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  • 1
    Digitale Medien
    Digitale Medien
    Response of the braconid parasitoid Cotesia (= Apanteles) glomerata to volatile infochemicals: effects of bioassay set-up, parasitoid age and experience and barometric flux (1992)
    Springer
    Entomologia experimentalis et applicata 63 (1992), S. 163-175 
    Details
    ISSN: 1570-7458
    Schlagwort(e): Hymenoptera ; Braconidae ; Lepidoptera ; Pieridae ; cabbage ; tritrophic interactions ; semiochemicals ; host-habitat location ; foraging behaviour
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Upon initiating a research project on the role of volatile infochemicals in the tritrophic system Cotesia (= Apanteles) glomerata (L.)-Pieris brassicae (L.)-cabbage, a bioassay was developed to investigate the response of C. glomerata. The bioassay should be effective in terms of high responsiveness and minimum variability and constructed through a comparative approach. Twenty seven treatments, organized in a factorial randomized block design, compared the effect of three bioassay set-ups (glasshouse flight chamber, wind-tunnel and Y-tube olfactometer), three parasitoid age groups (1–2, 4–5 and 8–9 days old females), three pre-treatment experiences (naive, damage experienced and oviposition experienced wasps) and the day-to-day effect on response of C. glomerata to clean cabbage (CC) and planthost complex (PHC) in a dual choice test. The best results with regard to the strength and consistency of response to the PHC were obtained in the glasshouse flight-chamber by 4–5 days old female wasps with either damage or oviposition experience (94 and 90%, respectively). It is therefore recommended as a suitable bioassay for studying the role of volatile infochemicals in host-habitat location by C. glomerata. A day-to-day variation in response was found in the glasshouse and wind-tunnel. It was correlated with the direction of change in barometric pressure within the time period of the experiment, showing that steadily increasing atmospheric pressure yields a significantly higher response than steadily decreasing or fluctuating barometric flux. To control for the day effect it is suggested to conduct further experiments in a block design, having day as a block. Several aspects of the infochemical ecology of C. glomerata are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00343576
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  • 2
    Digitale Medien
    Digitale Medien
    Control of codling moth in organically-managed apple orchards by combining pheromone-mediated mating disruption, post-harvest fruit removal and tree banding (1997)
    Springer
    Entomologia experimentalis et applicata 83 (1997), S. 137-146 
    Details
    ISSN: 1570-7458
    Schlagwort(e): Lepidoptera ; Tortricidae ; codling moth ; mating disruption ; Isomate-C ; tree banding ; organic apples ; biological agriculture
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract An integrated programme of pheromone-mediated mating disruption using Isomate-C®, post-harvest removal of fruit, and trapping overwintering larvae with cardboard tree bands, was used to control codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae), in four commercial ‘organic’ apple orchards in Cawston, British Columbia during 1989–1992. One application of 1000 dispensers − 1 on May 1 delivered estimated seasonal totals of 16.6, 16.5 and 19.9 g of E,E-8,10-dodecadien-1-ol [=codlemone] − 1in 1990, 1991 and 1992, respectively, at median rates of 8.4, 8.3, and 13.3 mg · 〈 ha−1 · ha−1 during dusk flight periods of first brood and 5.3, 4.7 and 4.6 mg · − 1· ha−1 in second brood, respectively. Over this 3-year period damage from codling moth at harvest ranged from 0.08 to 2.4%, and averaged 60.7% in these four organic orchards, while damage in five conventional orchards receiving sprays of azinphosmethyl ranged from 0.02 to 1.85%, and averaged 0.5%. Damage in an experimental orchard that was banded only, ranged from 43.5 to 56.7%, and averaged 48.9%. Between 1990 and 1992 cumulative male catches in Pherocon 1-CP wing traps baited with 10 mg of codlemone declined by 52% and densities of overwintering codling moth larvae declined an average of 49.5% in all organic orchards. Overwintering populations in the banded experimental orchard showed an increase of 57.7% during this study period. We conclude that an integrated programme of pheromone-mediated mating disruption, post-harvest fruit removal and tree banding, controls codling moth effectively enough to make organic apple production viable in British Columbia.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1002934116859
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  • 3
    Digitale Medien
    Digitale Medien
    The influence of tactile and other non-chemical factors on the ovipositional responses of the generalist herbivore Epiphyas postvittana (1997)
    Springer
    Entomologia experimentalis et applicata 83 (1997), S. 147-159 
    Details
    ISSN: 1570-7458
    Schlagwort(e): Lepidoptera ; Tortricidae ; visual stimuli ; tactile stimuli ; generalist
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A bioassay to test the ovipositional responses of the generalist herbivore, Epiphyas postvittana, was developed, and various non-chemical factors that influenced the laying, and number of eggs laid, by females were tested. In choice experiments using various models, surface texture was found to be an important factor influencing ovipositional behaviour, with females preferring to lay on smoother rather than rougher surfaces. Another surface texture feature that influenced oviposition was a raised wax ridge on a smooth surface. The wax ridge stimulated more eggs to be laid within close proximity to the ridge. Observations of females showed that the increased numbers of eggs laid on models with a wax ridge resulted not from increased landing, time spent, or numbers of eggs laid per ovipositional bout, but rather through an increased probability of ovipositing after landing on models with a wax ridge compared to models without the ridge. Spatial features of the models were also found to influence egglaying by females. Females showed a tendency to lay on the upper rather than the lower surface of models, although this appeared to depend upon how stimulatory the upper surface of the model was. Females also laid more eggs on models with a dense array of leaves than on models with a more spread-out array.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1002959605202
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  • 4
    Digitale Medien
    Digitale Medien
    Heritability of flight distance for Cydia pomonella (1997)
    Springer
    Entomologia experimentalis et applicata 85 (1997), S. 169-175 
    Details
    ISSN: 1570-7458
    Schlagwort(e): Cydia pomonella ; Lepidoptera ; Tortricidae ; flight distance ; dispersal ; flight mill ; heritability ; colonisation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Cydia pomonella L. (Lepidoptera: Tortricidae) is considered to be rather sedentary, but some individuals undertake flights of several kilometres in the field. This paper investigates the genetic influence on this variability. The flight capacity was measured in the laboratory by a flight mill and its heritability was estimated for two different strains. The laboratory strain was kept for more than 45 generations and the field strain from Embrach (northern Switzerland) was recently collected in the field. The multiple-trait-restricted-maximum-likelihood method was used for the estimation of genetic variances and covariances. A mixed full-sib/half-sib design was applied for the field strain and a full-sib design for the laboratory strain. The heritability of total distance was 0.57 for the field strain and 0.37 for the laboratory strain (both sexes). In addition, a heritability of 0.38 for total distance was estimated by parent-offspring regression for the laboratory strain. All three values were significantly different from zero P〈0.05 and show that there is a significant additive genetic influence on flight capacity. The genetic correlations between total distance and other flight traits (total duration, flight velocity, longest flight) were between 0.84 and 1.00 for both strains and suggest that these traits actually belong to a single one. High genetic correlations were also found between total distance and the morphological traits body weight and wing length for the field strain, whereas a negative correlation was found between total flight distance and body weight for the laboratory strain. This difference between the two strains was interpreted as a possible trade-off between flight capacity and fecundity.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1003195424159
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  • 5
    Digitale Medien
    Digitale Medien
    Effects of vegetation and weather on trap catches of Glossina fuscipes fuscipes near Lake Victoria, Kenya (1997)
    Springer
    Entomologia experimentalis et applicata 85 (1997), S. 231-236 
    Details
    ISSN: 1570-7458
    Schlagwort(e): Glossina fuscipes fuscipes ; vegetation ; biconical trap ; temperature ; light ; relative humidity ; monitor lizard
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Glossina fuscipes fuscipes Newstead was sampled in isolated thickets and forest patches near Lake Victoria, Kenya using unbaited biconical traps, between March 1992 and June 1993. Traps set at 1 m from the forest edge caught 3.3 times as many males and 5 times as many females as those set inside or 10 m away. The corresponding figures at 1 m from the edge of thicket were about 1.43 and 1.64 times, respectively. Hourly catches of males and females were positively correlated with temperature, light intensity and host (monitor lizard) prevalence, and negatively correlated with relative humidity. Light intensity and temperature were the most important variables affecting the catches of each sex. The results are discussed in relation to control and monitoring of G. f. fuscipes using traps.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1003179128955
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  • 6
    Digitale Medien
    Digitale Medien
    In vitro rearing of Campoletis sonorensis, a larval endoparasitoid of Heliothis virescens from egg to third instar in an artificial medium devoid of insect sources (1997)
    Springer
    Entomologia experimentalis et applicata 85 (1997), S. 263-273 
    Details
    ISSN: 1570-7458
    Schlagwort(e): in vitro rearing ; Campoletis sonorensis ; Hymenoptera ; Ichneumonidae ; Heliothis virescens ; Lepidoptera ; Noctuidae ; artificial medium ; sugars ; amino acids ; proteins ; luminosity ; medium volume
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Campoletis sonorensis is a solitary larval endoparasitoid of several Heliothis spp. pests. This study was carried out to develop media devoid of insect sources for in vitro rearing the parasitoid. Trehalose, lysine, threonine, asparagine, glutamine, hydroxyproline, serine, bovine serum albumin, and lactalbumin were beneficial to C. sonorensis. Addition of fresh chicken egg yolk at a low level improved the artificial media. Addition of 20-hydroxyecdysone increased the molting rate, reduced the critical size at molt and decreased development time. Parasitoid development in vitro was dependent on eggs that had been in the host for at least 22 h. Luminosity was also critical for the development of C. sonorensis in vitro. Optimal development occurred in a L14:D10 photoperiod at 43 Lux light intensity. Utilizing the best media and conditions, 100% of the parasitoid larvae reached the second instar and over 37% molted to the third instar. However, no further development occurred.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1003154918980
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  • 7
    Digitale Medien
    Digitale Medien
    Choosing a place to grow. Importance of within-plant abiotic microenvironment for Yponomeuta mahalebella (1997)
    Springer
    Entomologia experimentalis et applicata 83 (1997), S. 171-180 
    Details
    ISSN: 1570-7458
    Schlagwort(e): within-plant heterogeneity ; tent caterpillars ; temperature ; circular statistics ; Lepidoptera ; Yponomeutidae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The caterpillars of Yponomeuta mahalebella Latr. (Lepidoptera: Yponomeutidae) are monophagous on Prunus mahaleb (Rosaceae) leaves. Adult females deposit eggs in batches, which determines larval gregarious behaviour. Coupled with gregarious behaviour, caterpillars spin silk tents within they will feed until pupation. Distribution of tents in the field, their effect in microenvironmental larval growth conditions and the consequences for adult body mass and survival of larvae were studied. There was a significant trend for tents to be placed with a southward orientation. Within-plant tent orientation was related to the sun-shade pattern experienced, which was the main effect determining thermal differences between the inside and the outside of the tent. These differences appeared to affect larval growth and survival, with higher survival of larvae and heavier adults emerging from tents oriented to the south-east and east, respectively.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1002908817924
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  • 8
    Digitale Medien
    Digitale Medien
    Mortality of eggs, larvae and pupae and larval dispersal of the cabbage moth, Mamestra brassicae, in white cabbage in south-eastern Norway (1997)
    Springer
    Entomologia experimentalis et applicata 83 (1997), S. 347-360 
    Details
    ISSN: 1570-7458
    Schlagwort(e): dispersal ; Lepidoptera ; Mamestra brassicae ; mortality ; Noctuidae ; parasitism ; predation ; survival rate ; white cabbage
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The mortality of eggs, larvae and pupae and larval dispersal of the cabbage moth, Mamestra brassicae (L.) (Lepidoptera: Noctuidae) was investigated in a series of small-scale field experiments in white cabbage, Brassicae oleracea var. capitata (L.), and in the laboratory during 1990–1992 in south–eastern Norway. The highest mortality was found in young larvae and in hibernating pupae. In 1990, larval mortality in the first instar was 80% (range 9–97% for the individual cohorts). Most larvae died within the first 1–3 days after hatching. The dispersal activity during these days was high, and failure to establish feeding sites and predation were probably the main mortality causes. Pupal mortality during winter was 90% on average for 1990–1993 (range 81–100%). The main mortality factor was probably unfavourable weather conditions, and indications of cold stress were found. The impact from parasitoids and diseases was generally low. Trichogramma semblidis (Aurivillius) (Trichogrammatidae) was reared from M. brassicae eggs in very low numbers in 1991. Larval parasitism increased from 〈 1% in 1990 to almost 24% in 1992, and was almost totally caused by the braconids Microplitis mediator (Haliday) and Aleiodes (Aleiodes) sp. Predation of frozen larvae on the soil surface was 75% on average (range 63–96%) during 1990–1992 in first instar larvae and decreased gradually with larval age. The consumption rates of Philonthus atratus (Gravenhorst) (Staphylinidae) and the carabids Bembidion tetracolum (Say), Pterostichus melanarius (Illiger) and Harpalus rufipes (Degeer) on M. brassicae eggs and larvae were investigated in non-choice experiments in the laboratory. A preliminary survival model based on estimates of the mortality factors identified in this study is presented.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1003049010620
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  • 9
    Digitale Medien
    Digitale Medien
    Behavioral responses of lightbrown apple moth neonate larvae on diets containing Bacillus thuringiensis formulations or endotoxins (1997)
    Springer
    Entomologia experimentalis et applicata 84 (1997), S. 207-219 
    Details
    ISSN: 1570-7458
    Schlagwort(e): behavior ; feeding ; movement ; walking ; endotoxin ; Lepidoptera
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Behavioral responses of individual lightbrown apple moth, Epiphyas postvittana (Walker), neonate larvae to Dipel or the Bacillus thuringiensis delta endotoxins CryIAc and CryIBa incorporated into artificial diets were measured in choice and no-choice treatments. Frass production and the spinning of silken shelters were delayed when larvae were given diets containing Dipel or Bt endotoxins. In choice treatments larvae did not exhibit an initial preference for control diets over diets with Dipel or Bt endotoxins but accumulated on control diets over a period of days, apparently because larvae that first settled on Dipel or endotoxin diets abandoned diets while larvae that fed on control diets remained on diets throughout the experiment. Abandonment of diets containing Dipel or endotoxins was also apparent in no-choice treatments. Larvae exposed to such diets were more likely to be observed walking or at different sites from one observation to the next, and produced frass and silken feeding shelters at multiple sites rather than a single site. The implications of these findings for the use of B. thuringiensis as a commercial spray or for the use of B. thuringiensis endotoxin genes as resistance factors to be expressed in transgenic apples are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1003039630691
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  • 10
    Digitale Medien
    Digitale Medien
    Magnetometric Method of Investigating Fire Sites (1997)
    Springer
    Fire technology 33 (1997), S. 195-213 
    Details
    ISSN: 1572-8099
    Schlagwort(e): point of fire origin ; fire ; temperature ; plaster ; concrete ; thermal ; damage ; biotite ; magnetization ; susceptibility ; N-rays ; P-rays ; X-rays
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Notizen: Abstract Magnetic susceptibility (MS) measurements were taken to determine fire exposure patterns on noncombustible structural members and compartment boundaries. These measurements led on-site fire investigators to the cause of combustion and the point of fire origin. Thermal damage to walls and to ceilings was estimated quantitatively by measuring MS and two-valent Fe ion concentration in building materials such as concrete and plaster. It was shown that these effects are preconditioned by thermochemical transformations in the mineral biotite, which is present as a component of common building materials. For the first time, the effect of a substantial and irreversible increase in biotite magnetization exposed to powerful flows of N- and P-rays was found. It is hoped that the presence of this “magnetic trace” of radiation in building materials will allow investigators to use the magnetometric method at nuclear power plant catastrophes such as that in Chernobyl. It was also shown that the influence of N- and P-rays on biotite's magnetic properties greatly differs from the thermal influence on biotite.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1015363605037
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  • 11
    Digitale Medien
    Digitale Medien
    Effects of diet, photoperiod and temperature on the postdiapause reproduction in the cabbage bug,Eurydema rugosa (1992)
    Springer
    Entomologia experimentalis et applicata 64 (1992), S. 31-36 
    Details
    ISSN: 1570-7458
    Schlagwort(e): Eurydema rugosa ; adult diapause ; diet ; photoperiod ; temperature ; postdiapause development
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract InEurydema rugosa Motschulsky (Heteroptera: Pentatomidae), the type of food supplied (i.e. seeds or leaves of the brown mustard,Brassica juncea Hemsel) and photoperiod, which control the induction of adult diapause, do not play a role in the initiation of reproduction after overwintering. A temperature above 13.2°C was required to start reproduction. After its initiation, however, short-day conditions on seeds induced diapause again in some adults. Although a diet of seeds under long-day conditions, in common with short-day conditions, induced diapause in young adults (Numata & Yamamoto, 1990), it did not reinduce diapause in adults after overwintering. Thus,E. rugosa that had overwintered became sensitive to diapause-inducing photoperiod again but not to dietary factors.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00688991
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  • 12
    Digitale Medien
    Digitale Medien
    Diet-induced food preference by Manduca sexta larvae: acceptable non-host plants elicit a stronger induction than host plants (1992)
    Springer
    Entomologia experimentalis et applicata 63 (1992), S. 3-12 
    Details
    ISSN: 1570-7458
    Schlagwort(e): Feeding ; behaviour ; food preference induction ; diets ; Manduca sexta ; Lepidoptera
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Diet-induced changes in food preference by fifth instar larvae of the tobacco hornworm, Manduca sexta (Johan.) (Lepidoptera, Sphingidae), were examined. Two groups of larvae with different diet experience were used: larvae reared on a host or on an acceptable non-host plant species. Each group of larvae was offered a choice between leaf discs from each rearing plant species (2-plant choice test) and food preference was measured as the consumption of one plant species relative to that of the other plant species. Diet-induced changes in preferences were larger with the host versus acceptable non-host plant pairs Solanum pseudocapsicum (L.) versus Raphanus sativus (L.), Lycopersicon esculentum (Mill.) versus Vigna sinensis (Savi), and Datura innoxia (L.) versus V. sinensis than with the host versus host plant pairs L. esculentum versus Capsicum annuum (L.) and L. esculentum versus D. innoxia. To examine how much the food preference had been altered for each test plant species alone, two other groups of larvae were offered a choice between leaf discs from a single plant species and filter paper discs laced with distilled water (1-plant choice test). Larvae preferred the dietary plant species more strongly than the non-dietary plant species in tests using the following plant species: for C. annuum with C. annuum and L. esculentum as diets, for V. sinensis with V. sinensis and L. esculentum or D. innoxia as diets, and for R. sativus with R. sativus and S. pseudocapsicum as diets. The preference for the hosts L. esculentum and D. innoxia did not change significantly after rearing larvae on different hosts or on an acceptable non-host. Thus, diet-induction by M. sexta larvae results in an enhancement of preference for the dietary plant species which is much stronger with acceptable non-hosts than with hosts.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00350341
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  • 13
    Digitale Medien
    Digitale Medien
    Gut contents in molting lepidopteran larvae: a source of error in nutritional studies (1992)
    Springer
    Entomologia experimentalis et applicata 62 (1992), S. 87-91 
    Details
    ISSN: 1570-7458
    Schlagwort(e): Molting ; Lepidoptera ; nutritional indices
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00185646
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  • 14
    Digitale Medien
    Digitale Medien
    Resistance in certain maize cultivars to first and third-instar Chilo partellus larvae (1992)
    Springer
    Entomologia experimentalis et applicata 65 (1992), S. 75-80 
    Details
    ISSN: 1570-7458
    Schlagwort(e): Pyralidae ; Lepidoptera ; Zea mays L. ; Chilo partellus ; susceptibility
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The resistance/susceptibility levels of ten maize (Zea mays L.) cultivars to neonates and 3rd-instar larvae of Chilo partellus (Swinhoe) (Lepidoptera: Pyralidae) were measured in the field and screenhouse experiments. The maize cultivars tested were: Inbred A, Mp 704, V-37, Population 10, Hybrid 511, Katumani Composite B, ER-29 SVR, Poza Rica 7832, ICZ2-CM, and MMV 400. Most cultivars were found susceptible to 3rd-instar larvae based on the incidence of dead heart symptoms, foliar feeding and stem tunnelling caused by stem borers in both the field and screenhouse experiments. However, the maize cultivars V-37, MMV 400 and Poza Rica 7832 sustained significantly lesser damage than the other cultivars when infested with neonates or 3rd instar larvae. The screenhouse experiments conducted with five maize cultivars, i.e. Inbred A, Mp 704, V-37, ER-29 SVR, and Poza Rica 7832 showed that neonates fed less on the resistant than the susceptible maize cultivars but feeding by the 3rd instars was equally high on all the maize cultivars except Mp 704 on which the larvae fed less than the others. In the cultivars infested with neonates, the mean period for 50% moth emergence P50 was longest on Mp 704 followed by Poza Rica 7832, ER-29 SVR, V-37 and Inbred A. In the cultivars infested with 3rd-instars, P50 was longest for Poza Rica 7832 followed equally by the remaining cultivars. On the basis of the evidence presented we here conclude that neonates of C. partellus are sensitive to the growth inhibiting effects of the resistant maize cultivars Mp 704, V-37, and Poza Rica 7832 but the older larvae are insensitive to these effects of Mp 704 and V-37 but not of Poza Rica 7832.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00189719
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  • 15
    Digitale Medien
    Digitale Medien
    The role of temperature, photoperiod, crowding and plant quality on the production of alate viviparous females of the bird cherry-oat aphid,Rhopalosiphum padi (1992)
    Springer
    Entomologia experimentalis et applicata 65 (1992), S. 205-214 
    Details
    ISSN: 1570-7458
    Schlagwort(e): Bird cherry-oat aphid ; Rhopalosiphum padi ; alate development ; crowding ; photoperiod ; plant quality ; temperature
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Experiments indicated that for offspring of apterousRhopalosiphum padi (L.) (Hemiptera: Aphididae), photoperiod and crowding were the most important determinants of wing development whereas crowding and plant quality were more significant for the next generation. Plant quality became increasingly important as temperature increased while crowding became less so. More alates developed on plants previously infested with aphids, indicating that aphid feeding reduced plant quality. High temperature suppressed alatoid production, but could be overcome by crowding. Temperature appeared to influence wing development indirectly rather than directly by acting on the aphid through the plant. Adult weight and potential fecundity were also reduced for aphids which fed on previously infested plants.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02343853
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  • 16
    Digitale Medien
    Digitale Medien
    Diel flight periodicity of Chilo partellus (1992)
    Springer
    Entomologia experimentalis et applicata 65 (1992), S. 165-170 
    Details
    ISSN: 1570-7458
    Schlagwort(e): Lepidoptera ; Pyralidae ; stem borer ; suction trap ; behaviour ; maize ; dispersal ; pheromones ; activity
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The diel flight periodicity of the nocturnal moth Chilo partellus (Swinhoe) (Lepidoptera;Pyralidae) was measured in the laboratory using an actograph and in the field with suction traps. Females showed almost no flight activity on the night of eclosion. Flight activity of mated females peaked before midnight, the period of peak oviposition activity. Male peak activity occurred after midnight coinciding with female eclosion. Presence or absence of females did not affect when or how long males were active. Data on flight activity and reproductive behaviour are discussed in relation to the use of pheromones to protect maize.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00221367
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  • 17
    Digitale Medien
    Digitale Medien
    Electroantennogram, wind tunnel and field responses of male Mediterranean corn borer, Sesamia nonagrioides, to several blends of its sex pheromone components (1997)
    Springer
    Entomologia experimentalis et applicata 82 (1997), S. 121-127 
    Details
    ISSN: 1570-7458
    Schlagwort(e): Sesamia nonagrioides ; Lepidoptera ; Noctuidae ; sex pheromone ; pest monitoring ; electrophysiological behaviour ; EAG ; wind tunnel tests ; field tests ; (Z)-11-hexadecen-1-yl acetate ; (Z)-11-hexadecen-1-ol ; (Z)-11-hexadecenal ; dodecyl acetate
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The electrophysiological and behavioural responses of male Sesamia nonagrioides Lefèbvre (Lepidoptera: Noctuidae) to several synthetic blends of its sex pheromone components were investigated. Electroantennogram (EAG) recordings showed the greatest response to a 77:8:10:5 blend of the four compounds found in the female glands: (Z)-11-hexadecen-1-yl acetate, (Z)-11-hexadecen-1-ol, (Z)-11-hexadecenal and dodecyl acetate. A logistic equation was fitted to the dose-response data and differences in relative EAG responses were analysed by deriving five parameters of this equation. Flight responses of males were also evaluated in a wind tunnel where the proposed blend (77:8:10:5) also elicited the best response. Field tests confirmed the laboratory findings as the 77:8:10:5 blend captured more S. nonagrioides males than other pheromone mixtures and showed more selectivity for male S. nonagrioides over other noctuid species, Discestra trifolii Rottenberg and Lacanobia oleracea L., but not for Mythimna unipuncta Haworth, a species with a sex pheromone composition almost identical to that of S. nonagrioides.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1002948904264
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  • 18
    Digitale Medien
    Digitale Medien
    Reproduction of Diaeretiella rapae on Russian wheat aphid hosts at different temperatures (1997)
    Springer
    Entomologia experimentalis et applicata 82 (1997), S. 159-166 
    Details
    ISSN: 1570-7458
    Schlagwort(e): Diaeretiella rapae ; reproduction ; life-tables ; temperature ; Diuraphis noxia ; biological control
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Diaeretiella rapae (M'Intosh), a polyphagous and cosmopolitan parasite of aphids, was imported from China to the USA for biological control of Diuraphis noxia (Mordwilko), a pest of small grains. We studied several aspects of its biology on D. noxia hosts in the laboratory at 3 constant temperatures, 10.0, 21.1, and 26.7 °C. Females lived significantly longer than males at all 3 temperatures, and longevity was greatest at 10 °C, followed by 21.1 and 26.7 °C. Fecundity (= number of mummies) did not differ significantly among the 3 temperatures studied. The ovarian egg-load was 129.1 ± 9.3, and was significantly affected by the size of adult females. A pre-oviposition period ± 0.26 days) was detected at 10 °C, but not at the other temperatures. Pre-imaginal survivorship was similar among temperatures, while R o and T c decreased with temperature, and r m increased with temperature. The offspring sex ratio (proportion females) was lowest at 26.7 °C, and similar between 10.0 and 21.1 °C. In addition, the offspring sex ratio significantly declined with the age of the female parent. The suitability of D. rapae for colonization against D. noxia in North America is discussed in relation to its responses to temperature and the climate of its home range.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1002929500786
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  • 19
    Digitale Medien
    Digitale Medien
    Effects of light availability on host plant chemistry and the consequences for behavior and growth of an insect herbivore (1997)
    Springer
    Entomologia experimentalis et applicata 82 (1997), S. 319-333 
    Details
    ISSN: 1570-7458
    Schlagwort(e): chlorogenic acid ; light availability ; Lycopersicon esculentum ; Manduca sexta ; protein ; rutin ; temperature ; tomatine
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract We examined how light availability influenced the defensive chemistry of tomato (Lycopersicon esculentum: Solanaceae). Tomato plants were grown either in full sunlight or under shade cloth rated at 73%. Leaves from plants grown in full sunlight were tougher, had higher concentrations of allelochemicals (chlorogenic acid, rutin and tomatine), and had less protein than leaves from plants grown in shade. We determined how these differences in host plant quality due to light availability affected the behavior and growth of a Solanaceae specialist, Manduca sexta. Both in the greenhouse and in the field, caterpillars on shade-grown plants grew heavier in a shorter amount of time than those on plants that had previously been grown in full sunlight. In contrast, the effects of previous light availability to plants on caterpillar behavior appeared to be minor. To further investigate how light availability to plants influenced herbivore growth, we examined the effects of leaf-powder diets made from tomato leaves of different ages (new, intermediate, or mature) grown in full sunlight or shade on caterpillar performance. Caterpillars fed diets made from plants grown in shade consumed less but grew faster than larvae fed diets made from tomato plants grown in full sunlight. Caterpillars fed diets made from new leaves grew larger in less time than caterpillars fed diets made from intermediate aged leaves. Caterpillars did not survive on the mature leaf powder diets. There were plant-light treatment by larval thermal regime interactions. For example, at 26:15 °C , plant-light treatment had no effect on stadium duration, but at 21:10 °C, stadium duration was prolonged with the full sunlight-new leaf diet compared with the shaded-new leaf diet. In a second diet experiment, we examined the interactive effects of protein and some tomato allelochemicals (rutin, chlorogenic acid and tomatine) on the performance of caterpillars. There were food quality by thermal regime interactions. For instance, at 26:15 °C , neither protein nor allelochemical concentration influenced stadium duration, whereas at 21:10 °C, stadium duration was prolonged with the low protein-high allelochemical diet, which simulated full sunlight leaves. In sum, light availability to plants affected defensive chemistry and protein concentration. The difference in food quality was great enough to influence the growth of a specialist insect herbivore, but the effects were temperature-dependent.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1002916325052
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  • 20
    Digitale Medien
    Digitale Medien
    Inter- and intra-population differences in the effects of temperature on postdiapause development of Delia radicum (1997)
    Springer
    Entomologia experimentalis et applicata 84 (1997), S. 255-265 
    Details
    ISSN: 1570-7458
    Schlagwort(e): Delia radicum ; postdiapause development ; temperature ; Diptera ; Anthomyiidae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Canadian populations of D. radicum differ in their response to temperature during postdiapause development. Populations that are primarily of the early-emerging type ( $$\left( { \leqslant 256DD_{04} } \right)$$ ) (St-Jean, Quebec; London, Ontario) have high values for the parameters describing this response: % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamOuamaaBa% aaleaacaWGTbaabeaakiabg2da9aaa!38F2!$$R_m = $$ 12.7–13.3; $$T_m = $$ 28.0–31.8 °C ; Tσ = 10.3–14.2 ( $$R_m $$ , the maximum developmental rate at the temperature, $$T_m $$ [ °C ] where the developmental rate is highest, and Tσ , the parameter which gives the shape of the truncated normal curve fitted to the data), a low degree-day requirement for emergence (160–232 $$DD_{04} $$ ), and may lack a developmental delay at temperatures above ca. 21 °C . Populations of the late-emerging type (Kildare, Prince Edward Island) have low parameter values ( $$ R_m = 2.5$$ , $$T_m = 19.3$$ °C ; Tσ = 6.4), high degree-day requirements (530 $$DD_{04} $$ ), and a developmental delay at high temperatures. The parameters for the early-emergers in the population from Winnipeg, Manitoba (74% early) were intermediate ( $$R_m = 9.1$$ , $$T_m = 27.1$$ °C , Tσ = 10.7, $$ DD_{04} = 246 $$ ), but resembled the early rather than the late type. This population varied from 31 to 90% early type over a 10-year period and the rate of postdiapause development at 20 °C was directly related to the percentage early. In the year with the most rapid development (90% early), development was significantly slower than in the populations from other locations with predominantly early populations, and the year with the slowest development (31% early) showed significantly faster development than that from Kildare, Prince Edward Island (100% late). Therefore the parameters for early and late types of development will not be accurate for use in mixed populations, and the parameters in mixed populations will change among years. Populations of D. radicum in North America and Europe (67 locations by years) varied from 0–100% early. At Winnipeg, the percentage early was directly related to the annual temperature accumulation ( $$DD_{05} $$ ) during the growing season. The calculation of developmental parameters for the early-emergers of mixed populations provides a more accurate basis for estimating the times of first emergence and the first peak of emergence than parameters based on the whole population. Since postdiapause developmental rates vary both among and annually within locations, developmental models should be designed to include such variations.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1003048502446
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  • 21
    Digitale Medien
    Digitale Medien
    Oxidation of bridging groups by carboxylate coordinated ligands in palladium clusters (1992)
    Springer
    Journal of cluster science 3 (1992), S. 411-421 
    Details
    ISSN: 1572-8862
    Schlagwort(e): Palladium ; carbene ; oxidation ; phosphonate ; carboxylate
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Maschinenbau , Physik
    Notizen: Abstract Thermolysis of tetranuclear palladium clusters Pd4(μ-Q)4 Pd4(μ-Q)4(μ-O2CR)4 (Q=CPh2 or CO;R=Me, CMe3, Ph, CH2Cl or CF3) has been found to involve innersphere oxidation of carbene or carbonyl ligands during which an oxygen atom transfer occurs from the carboxylate group to the carbene or carbonyl ligand. The thermolysis of the carbonyl clusters gives rise to the products of CO2 insertion into the C–H bond of benzene or toluene used as solvents forming benzoic acid from benzene and a mixture of phenylacetic and toluic acids from toluene. The reaction of [Pd(OAc)2(PPh3)]2 with HCO2H includes the transfer of an O atom from formate ligand to the P atom and cleavage of the P-Ph bond accompanied by transfer of the Ph group from PPh3 ligand to the palladium atom. The structure of the complex formed, [Pd(μ-O2PPh2)(C6H5)(PPh3)]2, has been resolved by X-ray analysis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00702748
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  • 22
    Digitale Medien
    Digitale Medien
    Carbon monoxide electrooxidation on porous Pt–Ru electrodes in sulphuric acid (1997)
    Springer
    Journal of applied electrochemistry 27 (1997), S. 1275-1282 
    Details
    ISSN: 1572-8838
    Schlagwort(e): Carbon monoxide ; Pt-Ru/C catalyst ; Tafel slopes ; oxidation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Elektrotechnik, Elektronik, Nachrichtentechnik
    Notizen: Abstract CO electrooxidation on a Pt–Ru/C catalyst was investigated in sulphuric acid electrolyte. The physico-chemical properties of the Pt–Ru/C catalyst were studied by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The influence of temperature, CO partial pressure and proton concentration on the electrochemical oxidation rate was investigated by steady-state galvanostatic polarization measurements. The apparent activation energy decreased from 70 to 30kJmol−1 as the overpotential increased from 0.5 to 0.9V vs NHE. The reaction order with respect to carbon monoxide increased, passing from 0.4 to 1, with the increase of the overpotential from 0.5 to 0.7V vs NHE; a reaction order close to −1 with respect to the protonic concentration was observed, irrespective of the potential. Tafel slopes of about 136mVdec−1 were determined for oxidation of CO and CO/N2 mixtures.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1018492122263
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  • 23
    Digitale Medien
    Digitale Medien
    Effect of temperature on performanceof LaNi4.76Sn0.24 metal hydride electrode’ (1997)
    Springer
    Journal of applied electrochemistry 27 (1997), S. 1328-1332 
    Details
    ISSN: 1572-8838
    Schlagwort(e): metal hydride ; capacity ; temperature ; performance ; enthalpy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Elektrotechnik, Elektronik, Nachrichtentechnik
    Notizen: Abstract The effect of temperature on the performance of a LaNi4.76Sn0.24 metal hydride electrode was investigated in the temperature range of 0 to 50°C. The electrode showed a maximum discharge capacity at 25°C. The total resistance increases with a decrease of temperature from 50°C to 0°C. The apparent activation enthalpies at different states of charge were determined by evaluating the polarization resistance at different temperatures. It was found that the apparent activation enthalpy is an indicator of the relative reaction rate of the charge-transfer reaction and hydrogen absorption.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1018460709968
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  • 24
    Digitale Medien
    Digitale Medien
    MaleHeliothis virescens maintain upwind flight in response to experimentally pulsed filaments of their sex pheromone (Lepidoptera: Noctuidae) (1992)
    Springer
    Journal of insect behavior 5 (1992), S. 669-687 
    Details
    ISSN: 1572-8889
    Schlagwort(e): Heliothis virescens ; Noctuidae ; Lepidoptera ; upwind flight ; sex pheromone ; filaments
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Aspects of the intermittent fine structure of an odor plume were mimicked and experimentally modified in the wind tunnel using an air-pulsing device. Filaments of a behaviorally active blend of six sex-pheromone components created by the device in a temporally regular fashion elicited sustained upwind flight and source location in male Heliothis virescens.Males did not exhibit sustained upwind flight in significant numbers until a frequency of 4 filaments/s was delivered, at a loading of 1 μg of the major component, Z11-16: Ald, with the other components loaded at their appropriate ratios. A loading of 10 μg Z11-16: Ald was found to be optimal at this filament delivery rate. Electroantennogram recordings to different filament delivery rates of the complete blend indicated that a stationary male antenna can respond to the pulse rates used in this study. Importantly, when a main component necessary for upwind flight, Z9-14:Ald, was isolated into its own filaments and pulsed alternately against filaments of the five other components (including the other component essential for upwind flight, Z11-16: Ald), upwind flight to the source was significantly reduced (9%) compared to upwind flight and source location in response to filaments composed of the entire blend (30%), indicating that the complete pheromone blend must arrive on the antenna simultaneously for optimal evocation of sustained upwind progress. Neurophysiological evidence from other studies suggests that higher-order interneurons whose phasic response is enhanced when the entire blend is presented simultaneously may be of importance in explaining this behavioral difference stemming from synchronous vsasynchronous arrival of the components.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01047979
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  • 25
    Digitale Medien
    Digitale Medien
    Factors influencing the landing of maleEpiphyas postvittana (Walker) exhibiting pheromone-mediated flight (Lepidoptera: Tortricidae) (1992)
    Springer
    Journal of insect behavior 5 (1992), S. 699-720 
    Details
    ISSN: 1572-8889
    Schlagwort(e): sex pheromone ; landing behavior ; visual cues ; Epiphyas postvittana ; Lepidoptera ; Tortricidae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The effects of changes in various visual and olfactory properties of a white card surface on the landing position of male Epiphyas postvittanaexhibiting pheromone-mediated flight were studied in a wind tunnel. Males landed predominantly at the most downwind position of a surface in line with the pheromone source, regardless of the strength of the source. The position on the surface that males landed was strongly influenced by visual factors. The landing position of males appeared to be influenced by visual cues along all three axes of the surface. Decreases in either the dimension horizontally perpendicular to the wind direction or the vertical dimension resulted in greater numbers of males landing farther upwind on the surface than the downwind edge. Visual changes in the axis along the wind direction also affected the position at which males landed. For example, when presented with two white card surfaces with a 4- cm gap between them, males tended to land on the downwind edge of the upwind surface (on which the source was located). When the gap was bridged with clear Mylar, the landing pattern was significantly different, with the greater proportion of males landing on the downwind surface. However, when Mylar was placed on the plexiglass floor of the tunnel (in addition to bridging the gap), the landing pattern on the surface was not significantly different from that on the two surfaces without the Mylar bridge. It is suggested that during the prelanding and landing phases of pheromone-mediated flight, male moths orient to visual features of the surface containing the pheromone source rather than to visual features of the source (conspecific female moth) itself.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01047981
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  • 26
    Digitale Medien
    Digitale Medien
    Preparation and characterization of bimodal porous carbons derived from a styrene-divinylbenzene copolymer (1997)
    Springer
    Adsorption 3 (1997), S. 67-79 
    Details
    ISSN: 1572-8757
    Schlagwort(e): porous carbons ; activation ; oxidation ; surface oxygen groups ; LTPD
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Physik , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Abstract A styrene/divinylbenzene copolymer has been used as precursor for making porous carbons with bimodal pore size distributions (i.e., with both microporosity and mesoporosity). Pretreatment of the as-received copolymer by mild oxidation in air, significantly increased the carbon yield after carbonization. Reactivity studies of the polymer-based chars to CO2 clearly show the influences of some important factors such as carbonization temperature, heating rate, soak time on char reactivities. Bimodal porous carbons were prepared by carbonization of the preoxidized styrene/divinylbenzene copolymer in N2, followed by activation in CO2 at different temperatures to different levels of burnoff. The pore structures of the porous carbons produced have been characterized by various techniques such as gas adsorption and mercury porosimetry. The surfaces of the porous carbons produced, and a commercial carbon adsorbent, have been modified with HNO3 and H2O2 treatment at various conditions. Characterization of the surface oxygen functionality, both quantitatively and qualitatively, has been achieved using techniques such as Linear Temperature Programed Desorption (LTPD) and selective neutralization of bases.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01133008
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  • 27
    Digitale Medien
    Digitale Medien
    The Influence of Catalyst Composition on the Oxidation Process of Carbonado Type Synthesized Polycrystalline Diamonds (1997)
    Springer
    Advanced performance materials 4 (1997), S. 297-304 
    Details
    ISSN: 1572-8765
    Schlagwort(e): carbonado ; diamond ; oxidation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Maschinenbau
    Notizen: Abstract The oxidation of carbonado type synthesized polycrystalline diamonds produced from graphite together with catalytic Ni-Mo alloy doped with TiB2 and BNcub was investigated. It was found that the addition of these boron compounds increases the oxidation resistance of the carbonado type synthesized polycrystalline diamonds. The oxidation mechanism acting on the carbonado type synthesized polycrystalline diamonds and the role of boron compounds in increasing the resistance to the oxygen reaction are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1008677105534
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  • 28
    Digitale Medien
    Digitale Medien
    Mechanism for the formation of carbon dioxide in the catalytic oxidation of carbon monoxide and methane on silica (1992)
    Springer
    Catalysis letters 13 (1992), S. 283-288 
    Details
    ISSN: 1572-879X
    Schlagwort(e): Silica ; oxidation ; methane ; carbon monoxide ; carbon dioxide ; labelled reaction
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract The oxidation of carbon monoxide to carbon dioxide is shown to be catalyzed at 850 K or above over almost all lattice oxygen atoms on the surface of silica prepared by the sol-gel method from ethyl orthosilicate under conditions which yield high selectivity to carbon dioxide in the oxidation of methane.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00771001
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  • 29
    Digitale Medien
    Digitale Medien
    The partial oxidation of some cyclohexenes and branched chain olefins over a silver catalyst (1992)
    Springer
    Catalysis letters 16 (1992), S. 149-158 
    Details
    ISSN: 1572-879X
    Schlagwort(e): Silver ; oxidation ; cyclohexenes ; branched chain olefins
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract The oxidation of some cyclic and branched chain olefins over a silver catalyst effective for the conversion of ethylene to ethylene oxide has been investigated in a steady state flow system. The reaction of cyclohexene produces benzene and that of both 1-methylcyclohexene and 4-methylcyclohexene yields toluene. The selectivity to aromatics exceeds 20% for fractional conversions below 0.2, but it can be improved to almost 50% by inclusion of an optimum quantity of dichloroethane in the feed. Styrene is oxidised more slowly than the cyclohexenes and only carbon dioxide and water are produced. The oxidation of 3,3-dimethyl-1-butene and 3-methyl-1-butene occurs much faster than that of the cyclic molecules and some of the corresponding epoxides are produced. The selectivity with the dimethyl-butene is 9–13% for conversions to 0.2. The methylbutene requires a higher temperature for reaction and the epoxide yield is lower. Factors influencing reactivity and product distribution are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00764365
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  • 30
    Digitale Medien
    Digitale Medien
    The molecular structures and reactivity of V2O5/TiO2/SiO2 catalysts (1992)
    Springer
    Catalysis letters 13 (1992), S. 9-19 
    Details
    ISSN: 1572-879X
    Schlagwort(e): Vanadia ; titania ; silica ; Raman ; oxidation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract A series of V2O5/TiO2/SiO2 catalysts were structurally investigated byin situ Raman spectroscopy and chemically probed by methanol oxidation in order to determine the molecular structure-reactivity relationships of the V2O5/TiO2/SiO2 catalysts. Only surface TiO x species are present on the 3% TiO2/SiO2 catalysts, and the surface TiO x species as well as bulk TiO2 (anatase) particles coexist on the 40% TiO2/SiO2 catalyst. The deposition of 1–3% vanadium oxide onto 3% TiO2/SiO2 and 4% vanadium oxide onto 40% TiO2/SiO2 forms only a surface vanadium oxide phase.In situ Raman studies reveal that the surface vanadium oxide species preferentially exist on the titania sites of the TiO2/SiO2 system. The interaction between the surface vanadia and the surface titania overlayer on SiO2 increases the methanol oxidation reactivity by two orders of magnitude relative to V2O5/SiO2. In the presence of bulk TiO2 (anatase) particles on the SiO7 support, the reactivity of the surface vanadia further increases by an order magnitude relative to the catalysts containing only surface titania, and is close to that of surface vanadia on bulk TiO2. This suggests that the surface VO x -TiO2 (bulk) interactions results in a more active site than the surface VO x -TiO x -SiO2 interactions. In addition, the V2O5/TiO2/SiO2 catalysts exhibit high selectivity towards HCHO because redox sites are predominant on the surface of these catalysts with essentially no acid site present.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00770942
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  • 31
    Digitale Medien
    Digitale Medien
    High yield synthesis of propanal from methane and air (1992)
    Springer
    Catalysis letters 13 (1992), S. 341-347 
    Details
    ISSN: 1572-879X
    Schlagwort(e): Methane ; oxidation ; oxidative coupling ; hydroformylation ; propanal ; catalysis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract High yield synthesis of propanal from methane and air can be obtained in a single pass at atmospheric pressure. Three catalytic processes are combined to give 13% yield of propanal based on total methane input. Ethene is made from the oxidative coupling reaction and carbon monoxide and hydrogen is generated from partial oxygenation of methane. These gases are combined and passed to a hydroformylation catalyst to give liquid propanal. The unreacted methane is inert in the hydroformylation stage, while oxygen deactivates the catalyst readily. The results imply that propanal can be obtained, in good yield, from methane and air provided that total oxygen conversion is achieved. The yield of propanal from the three combined processes can be substantially higher than that of ethene from the oxidative coupling reaction. Thus, higher yields of a condensible and oxygenated product are obtained.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00765036
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  • 32
    Digitale Medien
    Digitale Medien
    Oxidation of acrolein on a multicomponent oxide catalyst (1992)
    Springer
    Catalysis letters 15 (1992), S. 401-404 
    Details
    ISSN: 1572-879X
    Schlagwort(e): Acrylic acid ; oxidation ; mixed oxides ; acrolein
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract Catalytic oxidation of acrolein to acrylic acid has been studied and the optimum composition of the multicomponent catalyst Mo a V b Cu c Fe d O x has been found. The reaction kinetics has been measured.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00769164
    Standort Signatur Erwartet Verfügbarkeit
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  • 33
    Digitale Medien
    Digitale Medien
    Effect of fluorination of alumina support on activity of platinum catalysts for complete oxidation of benzene (1997)
    Springer
    Catalysis letters 49 (1997), S. 155-161 
    Details
    ISSN: 1572-879X
    Schlagwort(e): fluorination ; alumina ; platinum catalysts ; oxidation ; oxidation of benzene
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract Platinum supported on fluorinated alumina is more active for the total oxidation of benzene than is the catalyst with the same Pt loading supported on hydrophilic unfluorinated alumina. The Pt-F/alumina catalyst contains well-dispersed small Pt particles, in contrast to Pt/alumina. The high dispersion is a consequence of a strong metal-support interaction.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1019065507551
    Standort Signatur Erwartet Verfügbarkeit
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  • 34
    Digitale Medien
    Digitale Medien
    Étude des principaux facteurs influençant l'émission d'attractifs sexuels synthétiques à partir de diffuseurs en caoutchouc et en plastique (1987)
    Springer
    Entomologia experimentalis et applicata 44 (1987), S. 123-130 
    Details
    ISSN: 1570-7458
    Schlagwort(e): composantes phéromonales ; diffusion ; température ; vent ; Z9-12:Ac ; 12:Ac ; Z9-14:Ac ; pheromonal components ; diffusion ; temperature ; wind ; Z9-12:Ac ; 12:Ac ; Z9-14:Ac
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Beschreibung / Inhaltsverzeichnis: Summary To determine the effect of various factors influencing the emission rate of pheromones from slow release dispensers, laboratory tests were undertaken with two types of rubber (Michelin) and one type of plastic trilaminate (Hercon®) dispenser. The effects of chain length, and the presence of double bonds were tested with three pheromonal compounds, Z9-12: Ac, 12: Ac and Z9-14: Ac impregnated on both types of rubber dispenser. The influences of temperature, wind velocity, humidity and percent loading were also tested. Data obtained indicated that chain length has a greater effect than the presence of a double bond. Amongst the climatic factors tested, wind speed has a greater effect than temperature while humidity has a minimal effect.
    Notizen: Abstract Deux types de diffuseurs en caoutchouc (Michelin) et en plastique polystratifié (Hercon®) sont testés en laboratoire pour étudier quelques aspects des phénomènes de diffusion. Trois composantes phéromonales, le Z9-12: Ac, le 12: Ac et le Z9-14: Ac imprégnées dans ces différents supports servent à détermineer le rôle joué par la longueur de la chaîne de la molécule et la présence de doubles liaisons sur la vitesse de diffusion. L'influence de la température, de la vitesse du vent et de l'humidité est déterminée en cellules climatisées. Parmi les facteurs relatifs à la structure chimique, l'influence de la longueur de la chaîne est prédominante par rapport à la présence d'une double liaison. Parmi les facteurs climatiques, le vent agit plus que la température sur la diffusion, alors que l'humidité paraît secondaire.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00367619
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  • 35
    Digitale Medien
    Digitale Medien
    Maintenance of innate feeding preferences by a polyphagous insect despite ingestion of applied deleterious chemicals (1987)
    Springer
    Entomologia experimentalis et applicata 44 (1987), S. 221-227 
    Details
    ISSN: 1570-7458
    Schlagwort(e): Antifeedants ; aversion learning ; fall armyworm ; feeding behavior ; polyphagy ; Spodoptera ; Lepidoptera
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Beschreibung / Inhaltsverzeichnis: Résumé Nous avons examiné si l'introduction d'une substance chimique nocive dans la plante-hôte préférée pouvait modifier la hiérarchie des choix durant le reste de la vie d'un insecte phytophage. Le comportement de préférence de Spodoptera frugiperda pour le maïs (Zea mays) vis à vis des Phaseolus, a été quantifié dans un dispositif à choix binaire, ont suivi des expériences au cours desquelles les chenilles devaient s'alimenter, soit sur maïs sain, soit sur maïs traité. Chaque essai concernait un composé chimique (15 au total), 13 étant des substances allélochimiques naturelles, 2 des insecticides de synthèse. Aux concentrations étudiées, aucun des produits n'a eu d'effet dissuasif. Les effets nocifs pendant l'exposition sur les chenilles comprenaient une croissance et une taille réduites, une irritation et, dans quelques cas, la mort. Aucune des expériences de choix binaire, avec des chenilles ayant subi cette exposition, n'a modifié les préférences. Cependant les chenilles, qui avaient été exposées au gossypol ou à l'acide monocarboxylique éthyl ester de chrysanthemum, ont consommé moins pendant les stades ultérieurs que ce que l'on pouvait attendre en absence de choix. Le degré d'aversion acquis par chaque chenille dépendait de l'importance des maux qu'elle avait subis précédemment.
    Notizen: Abstract The question of whether the appearance of a novel deleterious chemical in a preferred host plant could alter the relative degree of preference by a polyphagous insect during its lifetime was considered. The behavioral preference of fall armyworm, Spodoptera frugiperda (J. E. Smith), for corn (Zea mays L.) over red kidney bean Phaseolus spp. was quantified in a two-way choice test, and followed by a no-choice test in which the same larvae were fed either treated or untreated corn. Each treatment consisted of one of 15 compounds, including 13 naturally occurring allelochemicals and two synthetic insecticides. None of the test chemicals had any inherently deterrent effect at the rates tested. Deleterious effects on the larvae during exposure included reduced growth, reduced size, irritancy, and in some cases death. After this exposure the two way choice test was repeated. All test compounds failed to elicit a change in relative preference during the final two-way choice test. However, larvae exposed to gossypol and chrysanthemum monocarboxylic acid ester fed less than expected during the latter stages of no-choice conditions. The degree of aversion learning by each larva was related to the degree of prior sickness it had experienced.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00369182
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  • 36
    Digitale Medien
    Digitale Medien
    Regulation of body size in a heteropteran bug, Pyrrhocoris apterus (1987)
    Springer
    Entomologia experimentalis et applicata 44 (1987), S. 257-262 
    Details
    ISSN: 1570-7458
    Schlagwort(e): Heteroptera ; Pyrrhocoris apterus ; adult size ; egg weight ; starvation ; temperature ; pollution ; crowding ; duration of development
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Die Körpergrösse bei den Imagines eines Wildstammes der Feuerwanze Pyrrhocoris apterus wurde teilweise durch die Veränderlichkeit der Eigrösse determiniert, teilweise auch durch Hungern der Larven, niedrige Temperatur und metabolischen Produkten beeinflusst. Der Effekt letzterer Faktoren stieg mit deren Dauer und war je grösser desto näher sich die Wirkungsperiode zur Imaginalhäutung befand. Unterschiedliche Photoperioden wirkten auf die Körperlänge nicht. Wurden die Larven zwischen der ungünstigen Periode und der Imaginalhäutung noch den optimalen Bedingungen ausgesetzt, kompensierten sich die negativen Einflüsse weitgehend. Zu einer drastischen Verkleinerung der Imagines kam es nur, wenn das letzte Larven-stadium mit Hunger beeinflusst wurde und bis zur Imaginalhäutung keinen Zutritt zum Futter hatte. Minimales Gewicht, wo die Metamorphose der Larven noch möglich war, wurde zu 18 mg festgestellt.
    Notizen: Abstract The determination of body size (length or weight) of teneral adults of Pyrrhocoris apterus L. was investigated. About 50% of size variation was determined already in the egg stage (average egg weight adult length correlations were 0.67 in males and 0.71 in females). During the larval development, starvation, low temperature, and pollution by excreta combined with crowding reduced adult size and usually increased the development length. The effects were directly proportionate to the length of the stress period, and increased with larval age. Photoperiod or intrinsic variation of development time did not affect adult size. The effects of stress were largely compensated when it was followed by a period of compensation growth at optimum conditions. A dramatic reduction of size appeared when last inster larvae starved and moulted to adults without access to food. Average adult weight was then reduced by up to 48%. Threshold weight for adult moulting was 18 mg, being attained after 1–2 day feeding of the last instar.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00369187
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  • 37
    Digitale Medien
    Digitale Medien
    Survival of repeated frosts by the Queensland fruit fly, Dacus tryoni: experiments in laboratory simulated climates with either step or ramp fluctuations of temperature (1987)
    Springer
    Entomologia experimentalis et applicata 45 (1987), S. 9-16 
    Details
    ISSN: 1570-7458
    Schlagwort(e): Dacus tryoni ; fruit fly ; frosts ; cold ; survival ; winter ; step ; ramp ; cooling ; temperature
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Beschreibung / Inhaltsverzeichnis: Résumé L'aptitude à survivre à une ou plusieurs expositions à des températures inférieures à zéro dépend à la fois de leur sévérité et du laps de temps entre les expositions. L'effet d'une température minimale déterminée dépend de sa valeur, de sa durée et du type de refroidissement: brutal (step) ou progressif (ramp). Les effets de toute température minimale peuvent être exprimés en termes de LE50 (temps nécessaire pour obtenir une mortalité de 50% avec une exposition unique). Lorsque le temps d'application de la température minimale correspond à 35% du LE50, il n'y a pas de mortalité, de même dans le cas de répétitions quotidiennes. Lorsque le minimum est subi pendant 44% du LE50, il provoque environ 14% de mortalité après la première exposition, avec 3% supplémentaire après chaque exposition quotidienne, mais l'augmentation est nulle si l'exposition au froid n'a lieu que tous les 3 jours. Lorsque le minimum est subi pendant 88% de LE50, la mortalité après la première exposition est d'environ 40% et de même importance à chaque nouvelle exposition, même si elles sont espacées de 7 j. Lorsque la durée d'exposition au minimum correspond à 125% et à 150% de LE50, les mortalités sont respectivement d'environ 80% et 100% à la première exposition. La température maximale quotidienne, entre 15 et 25°C, semble avoir peu d'influence sur la mortalité provoquée par des expositions répétées à-5°C. Les mouches d'âges différents résistent de la même façon jusqu'à 6 expositions répétées à-6°C, mais au-delà les mouches âgées sont plus sensibles que les jeunes. Dans la mesure où, dans la nature, la durée d'exposition à la température minimale est connue et où la température dans le sol peut être calculée ou mesurée, ces résultats peuvent permettre d'interpréter la mortalité provoquée par le gel.
    Notizen: Abstract Ability to survive exposure to single or repeated periods at a subzero temperature is related to the temperature experienced, whether it is approached quickly or slowly, the time for which it prevails and the interval between exposures. The severity of any low temperature can be expressed in terms of LE50 (time required to kill 50% of individuals with one exposure). Minima enduring for 35% LE50 do not cause any mortality, even when repeated daily. Minima enduring for 44% LE50 cause ca 14% mortality on the first occurrence but no more if repeated at 3 day intervals, but 3% more per occasion if repeated daily. Minima enduring for 88% LE50 cause ca 40% mortality on first occurrence and an equal amount at each recurrence even if each is 7 days apart. Minima enduring for 125% LE50 and over 150% LE50 cause respectively ca 80% and 100% mortality respectively on first occurrence. The daily maximum temperature (in the range 15°C to 25°C) appears to have little relevance to the mortality caused by a repeated minimum of -5°C. Flies of different ages have a similar ability to survive a repeated minimum of -6°C for up to six exposures, but thereafter old flies are more susceptible than young ones. These results can be related to mortality caused by frosty conditions in the field so long as the time spent at the minimum is known and the temperature on the ground can be measured or calculated.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00343619
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  • 38
    Digitale Medien
    Digitale Medien
    The importance of the behaviour of young larvae in sorghum resistance to Chilo partellus (1987)
    Springer
    Entomologia experimentalis et applicata 45 (1987), S. 47-54 
    Details
    ISSN: 1570-7458
    Schlagwort(e): Lepidoptera ; Pyralidae ; Chilo partellus ; spotted stem borer ; resistance mechanism ; larval establishment ; egg infestation ; larval infestation ; bazooka applicator
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Beschreibung / Inhaltsverzeichnis: Résumé L'Institut International de Recherches sur les Cultures en Régions Semi-Arides (ICRISAT) étudie la protection contre C. partellus Swinhoe par l'utilisation de cultivars résistants. Différents cultivars présentent une résistance à différents stades de croissance de la plante, et à différents stades de l'insecte. La résistance du sorgho à C. partellus dépend de plusieurs mécanismes, l'un d'eux conditionnant l'installation des chenilles du premier stade dans le verticille de la plante. Cependant, la lenteur de l'installation d'est un facteur lié à la résistance que chez quelques cultivars. Plusiers facteurs physiques et chimiques sont associés à l'installation préférentielle des jeunes chenilles dans le verticille foliare. Parmi les caractères physiques, le port érigé des feuilles, la présence de poches à leur base et les cires superficielles sont impliqués dans l'installation des chenilles. Une analyse chimique détaillée d'extraits des structures superficielles a montré que la concentration d'une substance, le C32 “marqueur” de la lignée résistante IS 2205, était 2 fois plus faible que dans les lignées sensibles IS 1151 et CSH 1.
    Notizen: Abstract Management of spotted stem borer, Chilo partellus (Swinhoe) by the use of resistant cultivars is being developed at ICRISAT. Different cultivars show resistance based on several mechanisms, one of which affects the establishment of first instar larvae in the plant whorl. However, it has been found that low establishment is a factor associated with resistance only in some cultivars and not in others. A number of physical and chemical plant factors are associated with preferential establishment of the young larvae in the leaf whorl. Among the physical characteristics, erect leaves and curled leaf bases are involved in larval establishment. Detailed chemical analysis of surface extracts showed that the concentration of one compound in the wax is related to resistance at this stage and assessment of physical and chemical plant characters has been used to predict resistance.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00343624
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  • 39
    Digitale Medien
    Digitale Medien
    The effect of age of current-year shoots of Picea glauca on survival, development time, and feeding efficiency of 6th-instar larvae of Choristoneura fumiferana (1987)
    Springer
    Entomologia experimentalis et applicata 43 (1987), S. 251-260 
    Details
    ISSN: 1570-7458
    Schlagwort(e): spruce budworm ; Choristoneura fumiferana ; Lepidoptera ; Tortricidae ; white spruce ; Picea glauca ; food consumption ; survival ; development time ; artificial diet
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Beschreibung / Inhaltsverzeichnis: Résumé De la poudre lyophilysée de pousses de l'année de Picea glauca a été introduite dans le régime de chenilles du 6ème stade de Choristoneura fumiferana: 20% de poudre de pousses, 1.2% de gélifiant, 78.8% d'eau. Il est ainsi possible de déterminer à 2 mg près la quantité d'aliment consommée par chaque chenille, et, ainsi, de calculer, pour chacune, l'indice alimentaire, dont la prise de nourriture est l'une des variables. Avec de tels régimes préparés à partie de pousses recueillies au cours de 1983, on a constaté que la date de nymphose, la quantité consommée, et le poids ultérieur des papillons dépendaient du sexe de la chenille. En général, les chenilles femelles se nymphosent plus tard, consomment plus et donnent des papillons plus lourds (poids sec) que les chenilles mâles. L'efficacité de l'assimilation et celle de la transformation en biomasse de papillon ne différent pas suivant les sexes, c'est-à-dire qu'ils ont la même aptitude à digérer les pousses. Les taux de survie de chenille à nymphe et de nymphe à imago ne différent donc pas. Cependant, certains de ces paramètres et d'autres changent en fonction de l'âge des pousses annuelles. Quand elles ont été récoltées 7 jours après le débourrement (il a lieu le 20 mai), la survie jusqu'en nymphe est de 93% contre 74% de survie totale; avec des pousses récoltées 52 jours après le débourrement (11 juillet) les taux de survie sont respectivement 7% et 1.4%; avec des pousses récoltées 146 jours après le débourrement (13 octobre) les survies sont 71% et 50%. Des pousses récoltées 28 jours ou plus après le débourrement, retardent la date de nymphose de 25% par rapport à celles récoltées entre 7 et 14 après le débourrement; parallèlement, elles abaissent l'efficacité de l'assimilation de 39%, l'efficacité de conversion de la biomasse de 125%, et le poids des papillons de 54%. Ces changements sont liés à une diminution de la teneur en azote des pousses de 2.1% à environ 1% du poids sec. Cependant la corrélation entre la survie des chenilles et la teneur en azote n'est pas rigoureuse et un facteur encore inconnu est supposé responsable de l'augmentation de la mortalité quand les chenilles consomment (dans leur régime) des pousses récoltées début juillet, 52 jours après le débourrement. Les travaux destinés à identifier ce facteur inconnu sont en cours.
    Notizen: Abstract Diets prepared from lyophilized and powdered current-year (1983) shoots of white spruce Picea glauca (Moench) Voss were offered to 6th-instar larvae of spruce budworm, Choristoneura fumiferana (Clemens) (Lepidoptera: Tortricidae). With increasing age of current-year shoots, time to pupation increased whereas survival, assimilation efficiency, efficiency of conversion of diet to moth biomass, and moth dry weight generally decreased. Sex of the larvae influenced amount ingested, time to pupation, and subsequent moth weight but not survival, assimilation efficiency, and efficiency of conversion of diet to moth biomass.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00343557
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  • 40
    Digitale Medien
    Digitale Medien
    Pine monoterpenes stimulate oviposition in the pine beauty moth, Panolis flammea (1987)
    Springer
    Entomologia experimentalis et applicata 43 (1987), S. 295-297 
    Details
    ISSN: 1570-7458
    Schlagwort(e): Oviposition stimulants ; Panolis flammea ; Lepidoptera ; Noctuidae ; Pinus contorta
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00343565
    Standort Signatur Erwartet Verfügbarkeit
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  • 41
    Digitale Medien
    Digitale Medien
    The effect of oxide structure and cation reduction potential of vanadates on the selective oxidative dehydrogenation of butane and propane (1992)
    Springer
    Catalysis letters 12 (1992), S. 45-50 
    Details
    ISSN: 1572-879X
    Schlagwort(e): Propane ; butane ; alkane ; oxidation ; dehydrogenation ; vanadates ; cation reduction potential ; oxide structure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract The oxidative dehydrogenation of butane over a series of orthovanadates of cations of different reduction potentials showed a correlation that the selectivity for dehydrogenation decreased with increasing ease of reduction of the cation. The highest selectivity was observed on Mg orthovanadate. Mg pyrovanadate was nonselective for butane oxidation, but was as selective as Mg orthovanadate in propane oxidation. These results were interpreted by the different structures of the two Mg vanadates.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00767187
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  • 42
    Digitale Medien
    Digitale Medien
    The ozone sensitized oxidative conversion of methane to methanol and ethane to ethanol (1992)
    Springer
    Catalysis letters 16 (1992), S. 217-221 
    Details
    ISSN: 1572-879X
    Schlagwort(e): Methane ; ethane ; methanol ; ethanol ; ozone ; oxygen atom ; oxidation ; sensitization
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract The reaction of O2, O3, and CH4 or C2H6 of 7.76, 0.24 and 92% of the hydrocarbon respectively (residence time of 8.8 min) at 1 atm, and 400 °C for CH4 and 300 °C for C2H6 gave CO, CO2, H2O, CH2O and CH3OH from CH4 and in addition CH4, C2H4, CH3CHO and C2H5OH from C2H6. No reaction occurred when O3 was absent indicating that the partial oxidation was sensitized (initiated) by the oxygen atoms formed by the decomposition of ozone.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00764374
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  • 43
    Digitale Medien
    Digitale Medien
    Field activity of sex pheromone components of Peribatodes rhomboidaria (1987)
    Springer
    Entomologia experimentalis et applicata 44 (1987), S. 199-201 
    Details
    ISSN: 1570-7458
    Schlagwort(e): (Z,Z)-6,9-nonadecadien-3-one ; (Z,Z,Z)-3,6,9-nonadecatriene ; Peribatodes rhomboidaria ; Lepidoptera ; Geometridae ; sex pheromone ; field tests
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00367630
    Standort Signatur Erwartet Verfügbarkeit
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  • 44
    Digitale Medien
    Digitale Medien
    Influence of host-plants on the wind dispersal and the survival of an Australian geometrid caterpillar (1987)
    Springer
    Entomologia experimentalis et applicata 44 (1987), S. 289-294 
    Details
    ISSN: 1570-7458
    Schlagwort(e): Lepidoptera ; Geometridae ; Ectropis excursaria ; first instars ; wind dispersal ; survival ; host-plants ; host-selection
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Beschreibung / Inhaltsverzeichnis: Résumé Les femelles d'E. excursaria ne pondent pas là où les chenilles de premier stade s'alimentent. La dispersion par le vent, a été examinée comme l'un des éléments de la sélection de la plante-hôte par les chenilles du premier stade. Cette dispersion était influencée par la nature du végétal et par l'âge du feuillage. La dispersion à partir de 3 plantes de valeurs alimentaires différentes n'a pas été modifiée par le jeûne du premier stade. Le taux de survie, sur feuilles coupées et sur plantes en pot, a été aussi influencé par la nature du végétal. Il y a eu une corrélation positive significative entre le pourcentage de chenilles de premier stade restant sur le feuillage de l'hôte lors d'expériences de dispersion et le taux de survie sur ce feuillage. On peut suggérer que le comportement alimentaire polyphage des chenilles et la fécondité élevée des femelles peuvent avoir contribué à la stratégie de dispersion larvaire, comme processus de sélection larvaire, au détriment d'une sélection du lieu de ponte par les femelles.
    Notizen: Abstract The wind dispersal and survival of the first instars of a native polyphagous geometrid, Ectropis excursaria (Guenée) on Citrus sinensis (L.), Cupressus macrocarpa Hartw., Eucalyptus camaldulensis Dehn., Medicago sativa (L.) and Pinus radiata D. Don., were studied. A positive correlation existed between the percentage of caterpillars remaining on the foliage in dispersal experiments and the percent survival of caterpillars on these host-plants. The results are discussed in relation to the host-selection strategy of the first instars and the advantages of dispersal are compared for adult females and young larvae.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00369191
    Standort Signatur Erwartet Verfügbarkeit
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  • 45
    Digitale Medien
    Digitale Medien
    Physiological interactions and development synchronisations between non-diapausing Ostrinia nubilalis larvae and the tachinid parasitoid Pseudoperichaeta nigrolineata (1987)
    Springer
    Entomologia experimentalis et applicata 45 (1987), S. 157-165 
    Details
    ISSN: 1570-7458
    Schlagwort(e): Ostrinia nubilalis ; Pyralidae ; Lepidoptera ; Pseudoperichaeta nigrolineata ; Tachinidae ; Diptera ; larval development ; host-parasitoid relationship ; development synchronisation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Beschreibung / Inhaltsverzeichnis: Résumé Les relations physiologiques entre O. nubilalis et le tachinidae P. nigrolineata ont été étudiées dans des conditions abiotiques telles que l'hôte présente un développement sans diapause. Le parasitoïde ralentit la prise de poids de l'hôte: le poids maximal des chenilles parasitées ne représente que 78% de celui des chenilles saines. Seule la durée du 5ème stade est significativement plus longue chez les chenilles parasitées que chez les saines (10,4 contre 8,0 jours). L'influence de l'hôte sur le développement du parasitoïde à été expérimentée en parasitant des stades 2 à 5 d'O. nubilalis. Lorsque l'infestation a lieu au stade 2, le développement larvaire complet du parasitoî de dure deux fois plus longtemps que lorsque l'infestation a lieu au stade 5. Le meilleur rendement en pupes (50%) est obtenu lorsque l'infestation a lieu au stade 3. Il a été montré qu'il existe une bonne synchronisation entre le développement de l'hôte et de son parasitoî de. Il y a 4 phases physiologiques du développement larvaire de P. nigrolineata qui semblent nécessiter un signal provenant de l'hôte pour être dépassées. Ainsi peuvent être mis en relation: — le début de la croissance de la larve néonate du parasitoî de et l'ecdysis 3/4 de l'hôte; — la première mue du parasitoïde et l'ecdysis 4/5 de l'hôte; — la reprise de la croissance du stade II du parasitoïde, vers un poids de 1 mg et la remontée des taux d'ecdystéroïdes au milieu du stade 5 de l'hôte. et probablement, — la seconde mue du parasitoïde et l'apolyse nymphale de l'hôte. Les expérimentations vont se poursuivre pour déterminer les facteurs en cause. Ces phénomènes de synchronisation seront aussi étudiés dans le cas de la diapause de l'hôte.
    Notizen: Abstract The physiological relationships between Ostrinia nubilalis Hübner and its tachinid parasitoid Pseudoperichaeta nigrolineata Walker are described under abiotic conditions which induce development of the host without diapause. The parasitoid lowers the larval growth of the host: the maximal weight attained by the parasitized larvae represented only 78% of that of healthy ones. The duration of the last larval host instar increased to 10.4 days in parasitized O. nubilalis compared to 8.0 days in unparasitized ones. The influence of the host on the parasitoid development was studied experimentally after parasitization of O. nubilalis larvae of instars 2 to 5. When the second larval instar of the host is parasitized, the overall duration of parasitoid larval development lasts twice as long as when the fifth instar is parasitized. The best yield of parasitoid pupariae (50%) is obtained when parasitization occurs in instar 3. We show that good synchronisation exists between the larval development of the host and its parasitoid. There are four phases of parasitoid development which would appear to require a ‘signal’ from the host: the start of the growth of newly hatched parasitoid larvae and the 3rd to 4th instar ecdysis of the host; the first moulting of the parasitoid and the 4th to 5th instar ecdysis of the host; the growth resumption of the parasitoid instar II (weight about 1 mg) and the small rise of the ecdysteroid level in the middle of host instar 5; and in all probability, the second parasitoid moulting and the larval-pupal apolysis of the host.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00305642
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  • 46
    Digitale Medien
    Digitale Medien
    Effectiveness and persistence of the oviposition deterring pheromone of Pieris brassicae in the field (1987)
    Springer
    Entomologia experimentalis et applicata 45 (1987), S. 227-235 
    Details
    ISSN: 1570-7458
    Schlagwort(e): oviposition deterrent ; pheromone ; field experiments ; pre-oviposition behaviour ; dispersal ; Pieris brassicae ; Lepidoptera
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Beschreibung / Inhaltsverzeichnis: Résumé L'étude de l'efficacité de la phéromone dissuasive de la ponte (ODP) de P. brassicae a été effectuée au cours de petites expériences dans la nature. Dans des cages contenant des choux traités à l'ODP et des choux témoins, des femelles isolées ont été lâchées et leur comportement a été suivi jusqu'à ce qu'elles aient choisi un lieu de ponte. Dans les expériences sans plantes traitées à l'ODP, la ponte avait lieu uniformément sur les plantes de la cage. En présence de la phéromone, la ponte était concentrée sur les plantes situées sur deux côtés de la cage. La distribution des tentatives de ponte sur plantes témoins et traitées dans les expériences avec phéromone ne différait cependant pas de la distribution observée dans les expériences témoins. Ceci montre que pour ces conditions expérimentales dans la nature, l'efficacité finale de la phéromone est nulle. Cependant, la durée du comportement de préponte et le nombre moyen d'atterrissages pendant la sélection du lieu de ponte par les pondeuses était tous les deux accrus significativement en présence de phéromone. L'ODP a modifié aussi le nombre d'atterrissages sur les plantes témoins qui étaient plus élevés dans les expériences avec phéromone que dans les expériences témoins. Sans phéromone, les femelles libérées au centre de la cage avaient tendance à voler vers les parois de la cage. La présence d'ODP a stimulé ce comportement et, de plus, a dissuadé le retour des femelles vers le centre de la cage, réduisant ainsi la ponte sur les plantes au centre du lot. Des expériences de laboratoire avec des feuilles de plantes traitées dans la nature ont montré la persistance de la phéromone pendant au moins 5 jours dans les conditions de la nature. Nous en avons conclu que, dans la nature, ODP agit en modifiant le comportement de pré-ponte des femelles et en stimulant l'activité de dispersion, plutôt qu'en fournissant une protection absolue contre la ponte de P. brassicae.
    Notizen: Abstract In small-scale field experiments the potency of the oviposition deterring pheromone (ODP) of Pieris brassicae as a pest control agent has been studied. In a field cage containing control and ODP-treated cabbage plants, single females were released and their behaviour observed until they had selected an oviposition site. In experiments without ODP-treated plants, oviposition occurred evenly on plants throughout the cage. In the presence of the pheromone, oviposition was concentrated on plants along two sides of the cage. The distribution of oviposition attempts on control and treated plants in pheromone experiments, however, was not significantly different from that in the control experiments. This means that under these field conditions, i.e. within a cage, the ultimate effectiveness of the pheromone is nil. However, the duration of pre-oviposition behaviour and the mean number of landings during the site-selection process by ovipositing females were both found to be significantly increased in the presence of the pheromone. The ODP also affected the relative number of landings on control plants, which was higher in the pheromone runs than in the control runs. Without pheromone, females released from the center of the cage tended to fly to the sides of the cage. The presence of ODP stimulates this flight behaviour and, moreover, discourages females from returning to the center of the cage, thereby reducing oviposition on central plants in the field plot. Laboratory experiments with leaves from treated field plants indicated persistence of the pheromone under field conditions for at least 5 days. It is concluded that in the field the ODP acts as a modifier of female pre-oviposition behaviour and stimulates dispersal activity, rather than giving absolute protection against P. brassicae oviposition.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00343583
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  • 47
    Digitale Medien
    Digitale Medien
    Range of action of moth sex-attractant sources (1987)
    Springer
    Entomologia experimentalis et applicata 44 (1987), S. 5-14 
    Details
    ISSN: 1570-7458
    Schlagwort(e): Pheromone ; sex-attractant ; range ; attraction ; stimulation ; sampling ; Lepidoptera ; Cydia nigricana ; mark and recapture
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Observations and experiments which indicate the range of attraction of a sex-attractant source are distinguished from those which show its range of stimulation or sampling range. Published evidence of these ranges for lepidopteran sex-attractant sources is reviewed. In particular, evidence for the values of these three parameters for traps containing 100 μg of synthetic sex-pheromone of the pea moth, Cydia nigricana (F.), is presented, including the results of a timed mark and recapture experiment. It is concluded that for C. nigricana the ranges of attraction, stimulation and the daily sampling range for such a source placed in a cereal crop are at least 200, 500 and 500 m respectively.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00361302
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  • 48
    Digitale Medien
    Digitale Medien
    Hickory shuckworm Cydia caryana: electroantennogram and flight tunnel studies of potential sex pheromone components (1987)
    Springer
    Entomologia experimentalis et applicata 44 (1987), S. 23-30 
    Details
    ISSN: 1570-7458
    Schlagwort(e): Lepidoptera ; Tortricidae ; Olethreutinae ; Cydia caryana ; sex pheromone ; electroantennogram ; flight tunnel ; behavior
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Beschreibung / Inhaltsverzeichnis: Résumé Les réponses olfactives antennaires de Cydia caryana, mesurées par électroantennogrammes (EAG), aux alcools et acétates à carbones monounsaturés en positions 12 et 14, ont montré que le système conjugué de double liaison, (E)-8-, (E)-10- du dodecadien-1-ol acétate constitue un composé chimique strutural critique de la phéromone sexuelle de C. caryana. De plus, les acétates: (E)-8-dodecen-1-ol,(Z)-8-dodecen-1-ol,(Z)-9-dodecen-1-ol, et le (Z)-12-tetradecen-1-ol, se sont révélés en AEG comme des composés secondaires de la phéromone. L'étude par AEG de la relation dose-réponse a conduit à l'hypothèse de deux catégories de populations de récepteurs de phéromones. L'analyse comportementale des résponses des papillons mâles dans le tunnel de vol aux composés qui ont provoqués les plus forts AEG, on fait estimer que les acétates (E,E)-8,10-dodécadien-1-ol et (Z)-9-dodecen-1-ol ressemblent (ou sont) les constituants de la phéromone sexuelle de C. caryana; tandis que les (Z)-8-dodecen-1-ol et (E)-10-dodecen-1-ol sont, soit des paraphéromones, soit des constituants mineurs de la phéromone. La signification biologique du (Z)-12-tétradécen-1-ol a été difficile à interprêter avec les expériences en tunnel de vol.
    Notizen: Abstract Electroantennogram (EAG) measurement of male Cydia caryana moth antennal olfactory response to monounsaturated 12 and 14 carbon alcohols and acetates indicated that the (E)-8-, (E)-10- conjugated double bond system of a dodecadien-1-ol acetate is a critical chemical structural component of the C. caryana sex pheromone. Additionally, EAG measurements implicated (E)-8-dodecen-1-ol acetate, (Z)-8-dodecen-1-ol acetate, (Z)-9-dodecen-1-ol acetate and (Z)-12-tetradecen-1-ol as potential minor pheromonal components. An EAG dosage-response study suggested that there were at least two heterologous populations of pheromone acceptors. Behavioral analysis of male moth response in a flight tunnel to compounds which evoked the stronger EAG responses suggested that (E,E)-8,10-dodecadien-1-ol acetate and (Z)-9-dodecen-1-ol acetate resemble or are C. caryana sex pheromonal components, while (Z)-8-dodecen-1-ol acetate and (E)-10-dodecen-1-ol acetate are either parapheromones or are minor pheromone components. Behavioral significance of (Z)-12-tetradecen-1-ol was difficult to interpret in the flight tunnel.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00361305
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  • 49
    Digitale Medien
    Digitale Medien
    A pheromone mimic: disruption of mating communication in the navel orangeworm, Amyelois transitella, with Z,Z-1,12,14-heptadecatriene (1987)
    Springer
    Entomologia experimentalis et applicata 44 (1987), S. 249-255 
    Details
    ISSN: 1570-7458
    Schlagwort(e): Lepidoptera ; Pyralidae ; navel orangeworm ; Amyelois transitella ; pheromone mimic ; mating disruption ; Z,Z-1,12,14-heptadecatriene ; Z,Z-11,13-hexadecadienal
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Beschreibung / Inhaltsverzeichnis: Résumé Le Z-Z-1,12,14-heptacécatriène, qui mime l'aldéhyde Z-Z-11,13-hexadécadénial, principal composé de la phéromone de A. transitella Walker, a été essayé pour interrompre les accouplements dans la nature. Un conditionnement avec plastique stratifié a mieux dispersé le triène que la présentation en capsules de polyéthylène. Comme dans le cas des autres produits examinés précédemment, ce triène a interrompu l'attraction sexuelle (réduction du nombre de mâles capturés dans les pièges, réduction du nombre d'accouplements) de A. transitella dans les vergers d'amandiers, pendant moins longtemps que l'aldéhyde. Placé dans des pièges contenant des femelles vierges, il est efficace comme l'aldehyde pendant 5 semaines, pendant 3 semaines lorsqu'il est placé autour des pièges et pendant 13 jours quand il est utilisé dans des parcelles de 9 arbres. Des essais ultérieurs avec d'autres présentations et des quantités plus élevées de triène devraient montrer si ce produit peut être utilisé pour l'interruption des accouplements. Les analogues de phéromones ont généralement une plus grande stabilité et un coût de synthèse moins élevé que les aldéhydes.
    Notizen: Abstract A novel olefinic analog, Z,Z-1,12,14-heptadecatriene, was synthesized from Z,Z-11,13-hexadecadienal, a major pheromone component of the navel orangeworm, Amyelois transitella (Walker) (Lepidoptera: Pyralidae), and evaluated as a potential disruptant of mating communication in commercial almond orchards. The effectiveness of the triene as a disruptant was compared to that of the aldehyde by evaluating the reduction in captures of feral males in female-baited traps and the reduction in mating success for females. The triene was highly effective in bringing about reductions in male captures in traps in all tests relative to controls. This effectiveness lasted as long as 5 weeks in one test and was influenced by type of dispenser, release rate and proximity of dispensers to female-baited traps. In none of the tests did the triene outperform the aldehyde in reducing male captures. The results of mating success tests showed the triene to be ineffective relative to controls (26% reduction) while the aldehyde yielded 100% reductions in matings during a 6-day period.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00369186
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  • 50
    Digitale Medien
    Digitale Medien
    Effect of temperature on the duration of larval and pupal stages of two species of sciomyzid flies, predators of the snail Lymnaea truncatula (1987)
    Springer
    Entomologia experimentalis et applicata 43 (1987), S. 95-100 
    Details
    ISSN: 1570-7458
    Schlagwort(e): Ilione albiseta ; Pherbellia cinerella ; Diptera ; Sciomyzidae ; larva ; pupa ; temperature ; Lymnaea truncatula ; snails ; biological control
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Beschreibung / Inhaltsverzeichnis: Résumé L'action de la température a été examinée à 14, 17, 20, 23 et 26°C. Les 2 espèces sont prédatrices de L. truncatula, vecteur de la douve du foie en Irlande, où elle provoque à l'àgriculture une perte évaluée à 10 millions de livres par an. Les données recuellies en conditions contrôlées du laboratoire doivent permettre de définir les conditions optimales pour l'élevage continu de ces espèces. Ceci est indispensable pour évaluer, dans la nature leurs potentialités pour la lutte biologique. Ilione albiseta: C'est à 23°C que le développement des larves de premier et second stades sont les plus brefs; la survie du premier stade est totale à toutes les températures constantes examinées. La durée moyenne du 3ème stade décroît de 104 jours à 17°C jusqu'à 27,5 jours à 26°C. Le taux de survie total est plus élevé à 17°C qu'à 26°C. La durée moyenne de la nymphose diminue quand la température croît, et ceci se produit aussi à la température ambiante extérieure. On réduit de moitié la durée du développement de l'éclosion de l'oeuf à l'apparition de l'adulte, entre la nature et le laboratoire, en utilisant respectivement: 23°, 17° et 26°C pour les premier et second stades, le troisième stade, la nymphé. Cela devrait aider à multiplier la souche pour la lutte biologique. Pherbellia cinerella: Avec élévation de la température la durée du développement larvaire diminue, mais aussi le nombre de larves parvenant à la pupaison (100% à 14° et 33,3% à 26°C). La nymphose tendait à être plus brève aux températures les plus élevées.
    Notizen: Abstract The duration of larval and pupal stages of two species of predatory flies was investigated at five constant temperatures. Ilione albiseta (Scopoli): Mean duration of first and second instars was shortest at 23°C and there was 100% survival of first instar larvae at all temperatures. Mean third instar larval duration decreased from 104 days at 17°C to 27.5 days at 26°C. Total percentage larval survival was greatest at 17°C and least at 26°C. Mean pupal duration decreased as temperature increased and this occurred also under outdoor conditions. Pherbellia cinerella (Fallén): As temperature increased mean larval duration decreased but the percentage of larvae pupating also decreased (100% at 14°C, 33.3% at 26°C). There was a trend for shorter mean pupal durations at higher temperatures.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00350381
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  • 51
    Digitale Medien
    Digitale Medien
    Influence of fertilizer on southwestern corn borer, Diatraea grandiosella, infestation and damage to field corn (1987)
    Springer
    Entomologia experimentalis et applicata 43 (1987), S. 271-274 
    Details
    ISSN: 1570-7458
    Schlagwort(e): Southwestern corn borer ; Diatraea grandiosella ; Lepidoptera ; insects and fertilizer
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Beschreibung / Inhaltsverzeichnis: Résumé Nous avons étudié les corrélations entre l'utilisation d'engrais azotés et phosphatés d'une part, l'infestation et l'alimentation de D. grandiosella sur maïs en champs d'autre part. Les formules d'engrais comparées étaient: pas d'engrais, 90 et 179 kg N/ha sans P, 45 et 90 kg P/ha sans N, et les combinaisons de ces deux teneurs en N et P. La contamination était plus élevée dans les lots ayant reçu de l'azote que dans ceux traités sans N, mais la présence d'azote n'a pas réduit le décapage des tiges et la verse dus à l'alimentatin larvaire. A l'inverse, les lots n'ayant reçu que du phosphore avaient des pourcentages plus faibles de tiges contaminées par D. grandiosella et ainsi décapées et versées, que ceux qui n'avaient pas reçu P. Il n'a pas eu de différences significatives dans les contaminations ou les dégats entre les lots ayant reçu différentes combinaisons de N et P, et les effets de ces combinaisons sur l'insecte étaient intermédiaires à ceux de N et P seuls.
    Notizen: Abstract Nitrogen (N) and phosphorus (P) fertilizers have differing effects on southwestern corn borer (SWCB). Diatraea grandiosella Dyar, densities and damage to field corn, Zea mays L. Nitrogen fertilization of corn is associated with an increase in number of stalks infested and girdled by corn borers, while addition of P has the opposite effect. When combinations of N and P were applied, there were no significant differences in SWCB infestation or damage from plots receiving no fertilizer. The effect of combinations of N and P on SWCB were intermediate to either element alone.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00343560
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  • 52
    Digitale Medien
    Digitale Medien
    The influence of nutritional and genetic factors on larval performance of the cinnabar moth, Tyria jacobaeae (1992)
    Springer
    Entomologia experimentalis et applicata 62 (1992), S. 29-36 
    Details
    ISSN: 1570-7458
    Schlagwort(e): Alkaloids ; cinnabar moth ; insect genetics ; larval performance ; Lepidoptera ; nutritional ecology ; nitrogen ; sugar ; Tyria jacobaeae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract In a laboratory experiment using full-sibs, 60% of the variation in pupal weight of the monophage Tyria jacobaeae L. (Lepidoptera, Arctiidae) could be explained by variation in the nitrogen concentration of the food plant, Senecio jacobaea L. and only 4% by variation in sugar concentration. Larval weight and growth rates of young and old larvae were also positively correlated with nitrogen and sugar concentration. Developmental time was negatively correlated with nitrogen concentration. In a second experiment full-sib families differed significantly in larval weight at day 7, mortality, growth rate and developmental time. Pupal weight did not differ significantly among families, but was positively correlated with nitrogen concentration of Senecio. Larval performance was not significantly influenced by concentrations of sugars or alkaloids. We conclude that larval performance of Tyria during most of the larval period is mainly determined by genetic factors, but pupal weights are primarily determined by nitrogen concentration of the food plant.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00185638
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  • 53
    Digitale Medien
    Digitale Medien
    Deterrence of feeding and oviposition responses of adult Heliothis virescens by some compounds bitter-tasting to humans (1992)
    Springer
    Entomologia experimentalis et applicata 65 (1992), S. 81-93 
    Details
    ISSN: 1570-7458
    Schlagwort(e): Heliothis virescens ; Lepidoptera ; Noctuidae ; feeding behavior ; oviposition behavior ; electrophysiology ; deterrence ; antifeedant ; quinine ; quinidine ; atropine ; caffeine ; denatonium benzoate ; naringin ; sucrose octaacetate
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Some compounds that are bitter-tasting to humans, both alkaloidal (quinine, quinidine, atropine, caffeine) and non-alkaloidal (denatonium benzoate, sucrose octaacetate, naringin), deterred feeding and oviposition by Heliothis virescens (F.) in laboratory and field cage experiments. Preliminary electrophysiological studies of gustatory sensilla on the ovipositor of H. virescens provided evidence of 3 neurons, one of which is responsive to sucrose. Preliminary indications are that responses of this neuron may be inhibited by quinine and denatonium benzoate.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00189720
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  • 54
    Digitale Medien
    Digitale Medien
    Mating behaviour of the corn stalk borerSesamia nnonagrioides (1992)
    Springer
    Entomologia experimentalis et applicata 65 (1992), S. 199-204 
    Details
    ISSN: 1570-7458
    Schlagwort(e): Sesamia nonagrioides ; Lepidoptera ; Noctuidae ; calling behaviour ; mating behaviour ; circadian rhythm
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The mating behaviour of the corn stalk borerSesamia nonagrioides (Lef.) [Lepidoptera:Noctuidae] was studied under laboratory conditions at 25 ± 1 °C, 65 ± 5% r.h. and 16:8 (L:D) regime. The females began calling during the first scotophase following emergence, the peak of calling occurred during the second scotophase and thereafter decreased. Maximum calling was observed between the fourth and sixth hour of the scotophase. The calling pattern varied with age. During the first and second scotophase most of the females were calling continuously, while during the third and fourth scotophase periodic calling was observed. The mean onset of calling was advanced and the mean length of calling per day was increased slightly as the female became older. Females held for 72 h in continuous darkness exhibited an endogenous circadian rhythm of calling. Matings began during the first scotophase following emergence and the peak of mating was observed during the second scotophase. Mated females did not remate. Few males mated more than once during the following scotophases.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02343852
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  • 55
    Digitale Medien
    Digitale Medien
    Effect of time-dependent speed on frictional heat generation and wear in transient axisymmetrical contact of sliding (1997)
    Springer
    Archive of applied mechanics 67 (1997), S. 331-338 
    Details
    ISSN: 1432-0681
    Schlagwort(e): Key words frictional heating ; wear ; contact pressure ; temperature ; brake system
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Maschinenbau
    Notizen: Summary A transient contact problem with frictional heating and wear for two nonuniform sliding half-spaces is considered. One of the two half-spaces is assumed to be slightly curved to give a Hertzian initial pressure distribution: the other is a rigid nonconductor. Under the assumption that the contact pressure distribution could be described by Hertz formulas during all the process of interaction, the problem is formulated in terms of one integral equation of Volterra type with unknown radius of contact area. A numerical solution of this equation is obtained using a piecewise-constant presentation of an unknown function. The influence of operating parameters on the contact temperature and the radius of the contact area is studied.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004190050121
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  • 56
    Digitale Medien
    Digitale Medien
    Localization of spectral receptors in the ommatidium of butterfly compound eye determined by polarization sensitivity (1992)
    Springer
    Journal of comparative physiology 171 (1992), S. 289-297 
    Details
    ISSN: 1432-1351
    Schlagwort(e): Electrophysiology ; Lepidoptera ; Photoreceptor ; Spectral sensitivity ; Vision
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary 1. A butterfly Papilio has 5 types of spectral receptors in the compound eye. The spectral sensitivity of each type peaks in the UV, violet, blue, green, and red wavelengths, respectively. The green type contains two subtypes with and without a UV secondary peak. Here we studied the localization of these spectral receptors within the ommatidium. 2. An ommatidium contains 9 photoreceptors (R1–9), each of which is one of the 5 spectral receptor types. The photoreceptors bear parallel microvilli to form a nontwisted rhabdom, and thereby the photoreceptors are polarization sensitive. 3. We first examined the microvillar orientation by electron microscopy. The microvilli of R1, 2, and 9 are oriented dorso-ventrally (0°), whereas those of R3 and 4 are parallel to the antero-posterior axis (90°). The R5–8 bear microvilli diagonally: 45° for R6 and R8, 135° for R5 and R7. 4. We then recorded spectral and polarization sensitivities from single photoreceptors. The peak angle of the polarization sensitivity (θmax) of the UV, violet, and blue receptors were around 0°, whereas that of the green receptors was around 90°. In the double-peaked green receptors, the θmax at UV was also around 90°. The red receptors showed a θmax at around 35°. The polarization sensitivity ratio (PSmax/PSmin) of the double-peaked green receptors measured at UV was around 4, whereas the ratio of other receptors was around 2. 5. We conclude that R1 and R2 are either UV, violet, or blue receptors whereas R3 and R4 are green receptors. Some R6 and R8 are red receptors. We also conclude that the UV secondary peak in the double-peaked green receptor is not simply attributable to the coupling with UV receptors.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00223959
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  • 57
    Digitale Medien
    Digitale Medien
    High resolution measurement of atmospheric carbon dioxide concentration changes by the labial palp organ of the moth Heliothis armigera (Lepidoptera: Noctuidae) (1992)
    Springer
    Journal of comparative physiology 171 (1992), S. 317-324 
    Details
    ISSN: 1432-1351
    Schlagwort(e): Carbon dioxide ; Chemoreception ; Lepidoptera ; Microclimate ; Sensory transduction
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary In recordings of single unit action potentials, the responses of CO2-receptors in the labial palp organ of the moth Heliothis armigera to modulation of CO2-density around a background of 350 ppm were investigated. Modulation of CO2-density by square wave changes in concentration at constant barometric pressure evokes modulation of the spike rate. Modulation of CO2-density by square wave changes in barometric pressure at constant CO2-concentration evokes responses similar to those evoked by concentration modulation. For modulation depths of less than 1.5%, the output modulation depth is linearly related to the input; at higher modulation depths the gain decreases progressively. Using sinusoidal pressure modulation, the frequency dependence of both gain and output noise was determined over a range of 0.05 to 12.8 Hz. With increasing frequency the gain progressively increases at a rate of 2.4 dB/octave up to a maximum of 63 at 3 Hz; at higher frequencies, it decreases rapidly. The threshold sensitivity of the receptors, using input noise amplitude density as a criterion, is broadly tuned, with a minimum of 1 % contrast Hz-0.5 between 0.3 and 3 Hz. Using these figures, it is concluded that the sensory organ is capable of detecting fluctuations in CO2-density of 0.14% or 0.5 ppm. The results are related to the fluctuations in CO2-density which occur in a natural environment.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00223962
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  • 58
    Digitale Medien
    Digitale Medien
    Short-term dynamics in protein and amino acid metabolism (1997)
    Springer
    European journal of nutrition 36 (1997), S. 336-339 
    Details
    ISSN: 1436-6215
    Schlagwort(e): Amino acids ; protein ; metabolism ; meal feeding ; oxidation ; breath test ; Aminosäuren ; Protein ; Stoffwechsel ; Fütterung ; Oxidation ; Atemtest
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft , Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Die aktuellen Mengen an freien Aminosäuren im Blut reichen nur aus, um die Ganzkörper-Proteinsynthese für einige Minuten aufrecht zu erhalten. Das zeigt, daß die freien Aminosäurenkonzentrationen in der Zirkulation klein und konstant gehalten werden im Vergleich zu den Mengen der Aminosäuren, die täglich aufgenommen und über die Körperproteine umgesetzt werden. Das Verschwinden der Aminosäuren exogenen oder endogenen Ursprungs aus dem freien Aminosäuren-Pool, findet hauptsächlich durch die Proteinsynthese und den Aminosäurenabbau statt. Die Partitionierung der Nahrungs-Aminosäuren zwischen diesen beiden Prozessen im Kurzzeitbereich werden als bedeutsam für die Ökonomie der Ganzkörper-Aminosäuren angesehen. Eine Verbesserung der Aminosäurenökonomie könnte durch solche nutritiven Maßnahmen erreicht werden, welche die Clearance der Nahrungsaminosäuren durch die Proteinsynthese anstelle des Aminosäurenabbaus begünstigen. Diese nutritiven Maßnahmen sollten sich an den „Schwellenwerten“ des Abbaus der individuellen Aminosäuren orientieren.
    Notizen: Summary Actual amounts of free amino acids in the blood are sufficient to support whole body protein synthesis for some minutes only. This indicates that the levels of free amino acids in the circulation are kept small and constant relative to the amounts of amino acids supplied by daily intake and turnover of body proteins. The clearance of the amino acids originating from either endogenous or exogenous sources is mainly due to protein synthesis and metabolic degradation. The partitioning of dietary amino acids between these processes, on the short term, is supposed to play an important role in whole body amino acid economy. Therefore whole body amino acid economy could be improved by nutritional measures that favour the clearance of dietary amino acids by protein synthesis instead of by metabolic degradation. These nutritional measures should to be focused on threshold values for metabolic degradation of individual amino acids.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01617818
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  • 59
    Digitale Medien
    Digitale Medien
    C60: A host lattice for the intercalation of oxygen? (1997)
    Springer
    Microchimica acta 125 (1997), S. 401-406 
    Details
    ISSN: 1436-5073
    Schlagwort(e): fullerenes ; intercalation ; oxidation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract The investigation of structural and electronic properties of the novel family of fullerenes depends on the existence of pure reference materials. Sublimation of the van-der Waals solids is a suitable purification method. Little attention has been paid to the question about the air stability of such sublimed samples in form of crystals or thin films. A combination of thermal desorption spectroscopy, thermal analysis and diffuse reflectance FT-IR spectroscopy is used to show the extent to which oxygen from dry air is intercalated into fullerenes and which detrimental reactivity occurs from attempts to thermally remove („nneal”) air-exposed samples. The conclusion is that any fullerene sample exposed to air will be transformed in part into a polymeric non-fullerene carbon upon thermal treatment to above 400 K irrespective of its initial purity.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01246218
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  • 60
    Digitale Medien
    Digitale Medien
    Effect of environmental conditions and inoculum density on infection of guava fruits by Colletotrichum glososporioides (1997)
    Springer
    Mycopathologia 137 (1997), S. 165-172 
    Details
    ISSN: 1573-0832
    Schlagwort(e): Anthracnose ; guava ; Colletotrichum glososporioides ; temperature ; free moisture ; inoculum density
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract The influence of environmental factors (temperature and humidity), inoculum density on infection by Colletotrichum glososporioides and development of anthracnose lesions were determined on uninjured, sand-injured and punctured fruits. The optical temperature for severe infection was 30 °C, whereas the disease incidence was less at 20 and 35 °C. Inoculated guavas that received 1–60 h of continuous free moisture developed lesions, but the disease was minimal (0–7%) after 1–6 h free moisture. Infection rates of uninjured, sand-injured and punctured fruits receiving 60 h of free moisture were 34, 70 and 100%, respectively. Disease incidence increased as inoculum density increased from 101 to 106 conidia/ml. In field conditions, the development of anthracnose lesions was greater on punctured guavas than on uninjured or sand-injured ones, in both rainy and winter seasons. In general, the number of lesions was highest in sand-injured fruits, followed by punctured and uninjured fruits. In rainy season the number of lesions on injured and uninjured fruits was greater than similarly treated guavas in winter.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1006842801828
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  • 61
    Digitale Medien
    Digitale Medien
    Effect of temperature on antagonistic and biocontrol potential of shape Trichoderma sp. on Sclerotium rolfsii (1997)
    Springer
    Mycopathologia 139 (1997), S. 151-155 
    Details
    ISSN: 1573-0832
    Schlagwort(e): Antagonism ; biocontrol ; ginger ; postharvest rot ; Sclerotium rolfsii ; Trichoderma ; temperature
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract Sclerotium rolfsii is a destructive soil-borne and postharvest plant pathogen. Use of the antagonistic fungus Trichoderma sp. has been earlier reported by us to successfully control this pathogen under postharvest conditions. In the present paper we report on the effects of temperature on the growth and biocontrol potential of Trichoderma sp. on S. rolfsii. Experimental results indicated that S. rolfsii and Trichoderma sp. have different temperature optima for growth: 30–35 °C for the pathogen and 25–30 °C for the antagonist. In dual culture, Trichoderma overgrew S. rolfsii at 25 °C and 30 °C, but at 35 °C and 37 °C, S. rolfsii overgrew the colony of Trichoderma. Trichoderma produced higher concentration of fungitoxic metabolites in broth culture at higher temperatures. In bioassays using ginger slices and whole rhizomes, it has been demonstrated that Trichoderma is not very effective in suppressing S. rolfsii at temperatures above 30 °C. In light of these results, possible mechanisms of biocontrol of S. rolfsii as a postharvest pathogen has been discussed. Storage temperature has been suggested as a critical factor in biocontrol of S. rolfsii.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1006868009184
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  • 62
    Digitale Medien
    Digitale Medien
    Urea, ammonium sulfate and dicyandiamide transformations in Costa Rican soils (1987)
    Springer
    Nutrient cycling in agroecosystems 12 (1987), S. 255-261 
    Details
    ISSN: 1573-0867
    Schlagwort(e): nitrification ; nitrification inhibitor ; fertilizer N ; temperature
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract The transformations of urea, ammonium sulfate and dicyandiamide (DCD) were studied in an Inceptisol and three Andisols from Costa Rica, considering the influence of temperature and DCD as a nitrification inhibitor. Nitrification was very slow with or without DCD in the strongly acid Inceptisol. A higher urea dose resulting in higher pH was well nitrified without DCD and appreciably retarded by DCD. In Andisols nitrification was retarded as long as a higher DCD level existed. Higher temperatures accelerated the DCD-breakdown and were followed by a quicker nitrification. The decomposition of DCD was slower compared with the Inceptisol. According to these experiments DCD is suitable as a nitrification inhibitor in tropical soils.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01315109
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  • 63
    Digitale Medien
    Digitale Medien
    Evaluation and model of temperature and rainfall effects on response to N sources applied to grassland in spring (1987)
    Springer
    Nutrient cycling in agroecosystems 13 (1987), S. 255-267 
    Details
    ISSN: 1573-0867
    Schlagwort(e): urea ; ammonium nitrate ; model ; temperature ; rainfall ; grassland
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Direct and residual effects of urea and calcium ammonium nitrate (CAN) on dry matter (DM) response were measured at a total of 12 application times in early spring over three years. The variation in the direct effect was described by models that included temperature and long-term rainfall for CAN and, additionally, short-term rainfall for urea. The operative temperature was the accumulated mean daily air temperature for combined intervals pre-application and postapplication of N. The effect of rainfall was apparent only when the data were adjusted for temperature. Simulation studies with the models indicated that, although the influence of temperature was dominant, rainfall modified it strongly in terms of the relative efficiencies of the two N sources and the magnitude of response. For instance, the temperature-induced increase in DM response to urea between cold and normal years was 402 kg ha−1 for a specified period, whereas differences between dry and wet years were decreases of 166 and 259 kg ha−1 in the case of urea and CAN, respectively. Short-term rainfall had a positive effect on response to urea. The experimental values varied widely both between and within years. The direct effect of the application of urea at 50 kg N ha−1 varied from 0 to 750 kg DM ha−1, and the residual effect varied from 0 to 1620 kg DM ha−1. The corresponding values for apparent N recovery varied from 0.1 to 45% and from 7 to 68%, respectively. The efficiency of urea was comparable to, and in instances better than, CAN.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01066448
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  • 64
    Digitale Medien
    Digitale Medien
    Methane oxidation in soils with different textures and land use (1997)
    Springer
    Nutrient cycling in agroecosystems 49 (1997), S. 91-95 
    Details
    ISSN: 1573-0867
    Schlagwort(e): greenhouse effect ; land use ; methane ; oxidation ; soils
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Intact core samples from soils with different textures and land use were tested for their capacity to oxidise methane. The soil cores were taken from arable land, grassland and forest. It was found that coarse textured soils (6.74–16.38 µg CH4 m-2 h-1) showed a higher methane uptake rate than fine textured soils (4.66–5.34 µg CH4 m-2 h-1). Increasing soil tortuosity was thought to reduce the methane oxidation rate in fine textured soils. The oxidation rate of forest soils (16.32–16.38 µg CH4 m-2 h-1), even with a pH below 4.5, was very pronounced and higher than arable land (11.40–14.47 µg CH4 m-2 h-1) and grassland (6.74–9.30 µg CH4 m-2 h-1). Within the same textural class arable land showed a faster methane uptake rate than grassland. In grassland with a fine texture, even methane production was observed. Nitrogen availability and turnover in these land use systems were thought to cause the different oxidation rates. Decreasing the moisture content slowed down the oxidation rate in all soils. This could be caused by an increased N turnover and a starvation of the methanotrophic bacteria.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1009706324386
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  • 65
    Digitale Medien
    Digitale Medien
    The effect of agriculture on methane oxidation in soil (1997)
    Springer
    Nutrient cycling in agroecosystems 49 (1997), S. 59-70 
    Details
    ISSN: 1573-0867
    Schlagwort(e): land use ; methane ; nitrogen fertilizer ; oxidation ; soil
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Aerobic soils are an important sink for methane (CH4) contributing up to 15% of annual global CH4 destruction. However, the sink strength is significantly affected by land management, nitrogen (N) fertilizers and acidity. We tested these effects on samples taken from the Broadbalk Continuous Wheat, Park Grass permanent grassland and Broadbalk and Geescroft Wilderness experiments at Rothamsted. The rates of uptake from the atmosphere of both enhanced (10 ppmv) and ambient (2 ppmv) concentrations of CH4 were measured in laboratory incubations of soil cores under controlled conditions. The most rapid rates of uptake were measured in soil from deciduous woodland at pH 7 (measured in water); acidic (pH 4) woodland soil showed no net CH4 oxidation. While disturbance of the cores used in the experiments did not affect the rate of CH4 uptake, extended (150 years) cultivation of land for arable crops reduced uptake rate by 85% compared to that in the soil under calcareous woodland. The long-term application of ammonium- (NH4) based fertilizer, but not nitrate- (NO3) based fertilizer, completely inhibited CH4 uptake, but the application for the same period of farmyard manure that contained more N than the fertilizer had no inhibitory effect. Although the effects of agricultural practice on the oxidation of CH4 in soil are significant, the differences in oxidation rates between land use types are even greater. The likely effects of forest clearance, agricultural intensification and anthropogenic emissions of CH4 over the last 2500 years have been estimated for the United Kingdom. The calculations indicate that 54% of the current CH4 uptake by UK soils is the result of increased CH4 mixing ratio. They also indicate that land use change has decreased the potential sink strength by 62% or 37 kt CH4 g-1. In countries with much larger land areas than the UK, such as China, aerobic soil is likely to be a more significant factor in calculating net fluxes of CH4. It is important that the impacts of different agricultural managements and land use systems are understood and quantified so that the best possible estimate of CH4 sinks is calculated for comparison with sources.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1009704226554
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  • 66
    Digitale Medien
    Digitale Medien
    Targeting and translocation of mitochondrial precursor proteins (1992)
    Springer
    Antonie van Leeuwenhoek 61 (1992), S. 135-142 
    Details
    ISSN: 1572-9699
    Schlagwort(e): mitochondria ; precursor proteins ; import receptors ; general insertion sites ; protein folding
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00580621
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  • 67
    Digitale Medien
    Digitale Medien
    Effects of Interference and Oxidation on the UV/Visible Rejection Properties of Filters for Soft X-ray Detectors (1997)
    Springer
    Experimental astronomy 7 (1997), S. 51-63 
    Details
    ISSN: 1572-9508
    Schlagwort(e): X-ray ; calibration ; filters ; interference ; oxidation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Abstract We report on UV/Visible transmission measurements of aluminum coated Lexan filters designed as UV blocking filters for soft x-ray detectors. Transmission of the filters in the 2300-8000 Å wavelength range is significantly higher than expected. It cannot be accounted for applying a simple slab model of the transmission and adopting material properties reported in the literature. We show that this is due to interference effects which are strongly dependent on the filter geometry, and to oxidation of exposed aluminum surfaces and/or chemical interaction with the plastic support. The results of this work have led to the redesign of the Advanced X-ray Astrophysics Facility High Resolution Camera UV blocking filters.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1007919005280
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  • 68
    Digitale Medien
    Digitale Medien
    An inflated conservation load for European butterflies: increases in rarity and endemism accompany increases in species richness (1997)
    Springer
    Journal of insect conservation 1 (1997), S. 43-62 
    Details
    ISSN: 1572-9753
    Schlagwort(e): Lepidoptera ; biogeography ; endemism ; conservation ; butterflies
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Wissenschaftskunde und Wissenschaftsorganisation, Hochschul- und Universitätswesen, Museumswissenschaft
    Notizen: Abstract The addition of species to the European butterfly list since 1983 has resulted in a number of highly significant changes. Most important are the increases in the number and proportion of endemics and of rare species, and a regional excess of species and endemics for southern Europe compared to northern Europe. There is also a surplus of Lycaenidae and Satyridae compared to other families, and an increase in species per genus associated with the reduction in genera. These additions raise two issues. First, the potential conservation load for European butterflies is inflated at species level. This is especially the case for southern Europe, which has disproportionate increases in rare and endemic species, more particularly if rarity and endemism are found to equate with threat of extinction. Second, the inflation in rarity and endemism suggests that there is a trend to promote ever more local populations (races, subspecies) to species. The taxonomic status of species being added to the list, a quarter of which are regarded as doubtful, is increasingly difficult to determine. Consequently, there is a danger that this may call into question the validity and objectivity of taxonomic practices, and of databases dependent on them, used by conservation. Revision of higher and lower butterfly taxa is urgently required.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1018474824448
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  • 69
    Digitale Medien
    Digitale Medien
    Antioxidant alteration ofGlycine max (Fabaceae) defensive chemistry: Analogy to herbivory elicitation (1992)
    Springer
    Chemoecology 3 (1992), S. 25-32 
    Details
    ISSN: 1423-0445
    Schlagwort(e): defensive chemistry ; alterable ; elicitation ; herbivory ; antioxidant ; Fabaceae ; Glycine max ; Lepidoptera ; Noctuidae ; Trichoplusia ni
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The water-soluble antioxidant, L-ascorbic acid (vitamin C), proved elicitory to alterable anti-herbivory inGlycine max againstTrichoplusia ni larvae. Elicitation by vitamin C was influenced especially by dose, time after elicitation and space in the plant. Results allow an analogy between antioxidant and herbivory elicitation. Elicitation apparently involves a sulfhydryl-protein-dependent redox mechanism which can be significantly affected by antioxidants. Findings would also support a proposed common redox-based mechanism, involving the plasma membrane, for communication between plant and animal cells and their environments.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01261453
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  • 70
    Digitale Medien
    Digitale Medien
    Cardenolide content, emetic potency, and thin-layer chromatography profiles of monarch butterflies,Danaus plexippus, and their larval host-plant milkweed,Asclepias humistrata, in Florida (1992)
    Springer
    Chemoecology 3 (1992), S. 1-13 
    Details
    ISSN: 1423-0445
    Schlagwort(e): aposematism ; cardenolide fingerprint ; chemical defense ; emesis ; plant-insect interaction ; migration ; Asclepiadaceae ; Apocynales ; Asclepias humistrata ; milkweed ; Lepidoptera ; Danainae ; Danaus plexippus ; monarch butterfly
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary This paper is the fourth in a series on cardenolide fingerprints of monarch butterflies (Danaus plexippus, Danainae) and their host-plant milkweeds (Asclepiadaceae) in the eastern United States. Cardenolide concentrations ofAsclepias humistrata plants from north central Florida ranged from 71 to 710 µg/0.1 g dry weight, with a mean of 417 µg/0.1 g. Monarchs reared individually on these plants contained cardenolide concentrations ranging from 243 to 575 µg/0.1 g dry weight, with a mean of 385 µg/0.1 g. Cardenolide uptake by butterflies was independent of plant concentration, suggesting that sequestration saturation occurs in monarchs fed cardenolide-rich host plants. Thinlayer chromatography resolved 19 cardenolides in the plants and 15 in the butterflies. In addition to humistratin,A. humistrata plants contained several relatively non-polar cardenolides of the calotropagenin series which are metabolized to more polar derivatives in the butterflies. These produced a butterfly cardenolide fingerprint clearly distinct from those previously established for monarchs reared on otherAsclepias species. In emetic assays with the blue jay,Cyanocitta cristata, the 50% emetic dose (ED50) per jay was 57.1 µg, and the average number of ED50 units per butterfly was 13.8, establishing that this important south eastern milkweed produces highly emetic, chemically defended monarchs. Our data provide further support for the use of cardenolide fingerprints of wild-caught monarchs to make ecological predictions concerning defence against natural enemies, seasonal movement and larval host-plant utilization by monarch butterflies during their annual cycle of migration, breeding and overwintering.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01261450
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  • 71
    Digitale Medien
    Digitale Medien
    Leaf surface chemicals stimulating oviposition byPieris rapae (Lepidoptera: Pieridae) on cabbage (1992)
    Springer
    Chemoecology 3 (1992), S. 33-38 
    Details
    ISSN: 1423-0445
    Schlagwort(e): oviposition ; 3-indolylmethyl glucosinolate ; sinigrin ; glucoiberin ; cabbage ; Cruciferae ; Brassica oleracea ; Lepidoptera ; Pieridae ; Pieris rapae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The chemical stimulation of oviposition byPieris rapae on cabbage was investigated by leaf washing and extraction. Isolation of the stimulant by various chromatographic techniques was monitored by a bioassay using Sieva bean as a surrogate host plant. Cold water, chloroform, or chloroform followed by cold water washes failed to release the stimulant from leaf surfaces. Boiling water or chloroform followed by methanol was required. The most active stimulatory compound was identified as 3-indolylmethyl glucosinolate (glucobrassicin). Other glucosinolates were identified as sinigrin, which was only slightly active, and glucoiberin, which was completely inactive as a stimulant. The significance of the selective response ofP. rapae andP. brassicae to different glucosinolates and the implications of the binding of polar allelochemicals to leaf surfaces is discussed with respect to host utilization and perception mechanisms of pierids.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01261454
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  • 72
    Digitale Medien
    Digitale Medien
    Survival of first instar larvae ofDanaus plexippus (Lepidoptera: Danainae) in relation to cardiac glycoside and latex content ofAsclepias humistrata (Asclepiadaceae) (1992)
    Springer
    Chemoecology 3 (1992), S. 81-93 
    Details
    ISSN: 1423-0445
    Schlagwort(e): first instar survival ; latex ; cardiac glycosides ; cardenolides ; Lepidoptera ; Danainae ; Danaus plexippus ; Asclepiadaceae ; Asclepias humistrata ; milkweed
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Our paper addresses field survivorship of first instar monarch butterfly larvae (Danaus plexippus L., Lep.: Danainae) in relation to the dual cardenolide and latex chemical defenses of the sand hill milkweed plant,Asclepias humistrata (Asclepiadaceae) growing naturally in north central Florida. Survival of first instar larvae in the field was 11.5% in the first experiment (15–20 April 1990), and dropped to 3.4% in the second experiment (20–30 April). About 30% of the larvae were found glued to the leaf surface by the milkweed latex. Predator exclusion of non-flying inverte-brates by applying “tanglefoot” to the plant stems suggested that the balance of the mortality was due to volant inverte-brates, or to falling and/or moving off the plants. Regression analyses to isolate some of the other variables affecting survivorship indicated that first instar mortality was correlated with (1) increasing cardiac glycoside concentration of the leaves, (2) increasing age of the plants, and (3) the temporal increase in concentration of cardiac glycosides in the leaves. The study also provided confirmatory data of previous studies that wild monarch females tend to oviposit onA. humistrata plants containing intermediate concentrations of cardiac glycosides. Cardiac glycoside concentration in the leaves was not correlated with that in the latex. The concentration of cardenolide in the latex is extremely high, constituting an average of 1.2 and 9.5% of the mass of the wet and dry latex, respectively. The data suggest that an increase in water content of the latex is compensated for by an influx of cardenolide with the result that the cardenolide concentration remains constant in the latex systems of plants that are growing naturally. We also observed first instar larvae taking their first bite of milkweed leaves in the field. In addition to confirming other workers findings that monarch larvae possess elaborate “sabotaging” behaviour of the milkweed's latex system, we discovered that several larvae on their first bite involuntarily imbided a small globule of latex and instantly became cataleptic. This catalepsis, lasting up to 10 min, may have been in response to the high concentration of cardenolide present in the latex ofA. humistrata, more than 10 times that in the leaves. The results of the present study suggest that more attention should be directed to plant chemical defenses upon initial attack by first instar insect larvae, rather than attempting correlations of plant chemistry with older larvae that have already passed the early instar gauntlet. The first bite of neonate insects may be the most critical moment for coping with the chemical defenses of many plants and may play a much more important role in the evolution of insect herbivory than has previously been recognized.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01245886
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  • 73
    Digitale Medien
    Digitale Medien
    Nest structure and colony cycle of the Allegheny mound ant,Formica exsectoides Forel (Hymenoptera: Formicidae) (1992)
    Springer
    Insectes sociaux 39 (1992), S. 385-402 
    Details
    ISSN: 1420-9098
    Schlagwort(e): Formica exsectoides ; nests ; colony cycle ; temperature ; brood ; reproductives
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The nest structure and colony cycle of a population of Allegheny mound ants,Formica exsectoides, were examined in central Michigan. The dispersion pattern of mounds was random. Nest structure and presence of brood were primarily determined by excavation of twenty-three nests over three intervals from June through September. Additional excavations of five nests in 1990 and ten nests in 1991 provided further details on nest structure and colony cycle. Most galleries occurred within the mound and upper 30 cm of soil, but some activity reached depths of 100 to 270 cm. Depth of nests showed little correlation with external measurements of height and diameter. Immature stages were recovered from two strata: the upper 20 cm of nest and mound and the lowest nest depths. Alate sexual forms were found in or near the mound in July, and numerous dealate queens were collected in September from peripheral galleries near the soil surface.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01240623
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  • 74
    Digitale Medien
    Digitale Medien
    GMP-stimulation of the cyanide-insensitive mitochondrial respiration in heat-shocked conidia ofNeurospora crassa (1987)
    Springer
    Cellular and molecular life sciences 43 (1987), S. 439-440 
    Details
    ISSN: 1420-9071
    Schlagwort(e): Neurospora crassa ; conidia ; heat-shock ; mitochondria ; cyanide-insensitive respiration ; guanosine 5′-monophosphate (GMP)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary In mitochondria of heat-shocked conidia ofNeurospora exogenous NADH and succinate were oxidized mainly via the alternative, hydroxamate-sensitive pathway (70%) and only 30% via the cytochromic, cyanide-sensitive pathway which was predominant in untreated conidia; the alternative oxidase pathway was markedly stimulated by guanosine 5′-monophosphate (GMP).
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01940445
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  • 75
    Digitale Medien
    Digitale Medien
    Identification of an oviposition-regulating pheromone in the European grapevine moth,Lobesia botrana (Lepidoptera: Tortricidae) (1992)
    Springer
    Cellular and molecular life sciences 48 (1992), S. 697-699 
    Details
    ISSN: 1420-9071
    Schlagwort(e): Oviposition-deterring pheromone ; Lepidoptera ; Tortricidae ; Lobesia botrana ; eggs ; fatty acids ; esters of fatty acids
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract The oviposition of the European grapevine moth (EGVM)Lobesia botrana can be deterred by an extract of conspecific eggs corresponding to 20 egg equivalents. The reduction of the oviposition behavior is dose-dependent. Nine chemicals have been extracted from the eggs and identified as straight chain fatty acids and esters of fatty acids. A mixture of these rather simple molecules induces the same levels of deterrence as the total extract. It might be possible to use oviposition regulating pheromone in the future for the control of EGVM populations.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02118323
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  • 76
    Digitale Medien
    Digitale Medien
    Hummingbird flight: Sustaining the highest mass-specific metabolic rates among vertebrates (1992)
    Springer
    Cellular and molecular life sciences 48 (1992), S. 565-570 
    Details
    ISSN: 1420-9071
    Schlagwort(e): Oxygen consumption ; exercise ; evolutionary design ; muscle ; mitochondria ; energy metabolism ; enzymes
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract Resting and maximal mass-specific metabolic rates scale inversely with body mass. Small hummingbirds achieve the highest known mass-specific metabolic rates among vertebrate homeotherms. Maximal capacities for O2 and substrate delivery to muscle mitochondria, as well as mitochondrial oxidative capacities in these animals may be at the upper limits of what are structurally and functionally possible given the constraints inherent in vertebrate design. Such constraints on the evolutionary design of functional capacities may play an important role in determining the lower limits to vertebrate homeotherm size and the upper limits to mass-specific metabolic rate.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01920240
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  • 77
    Digitale Medien
    Digitale Medien
    The temperature stratification and related characteristics of Chilean lakes in midsummer (1992)
    Springer
    Aquatic sciences 54 (1992), S. 37-57 
    Details
    ISSN: 1420-9055
    Schlagwort(e): Chile ; monomictic lakes ; temperature ; mixing ; heat budget ; stratification
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Temperature profiles in summer (February/March 1990) were measured in 24 lakes along a latitudinal transect from central Chile (32° S) to Patagonia (47° S), and on Easter Island (27° S). The lakes of the temperature zone, between 47° S and 38° S, are warm monomictic with surface and deep-water temperatures ranging from 12 °C to 21 °C and from 5.5 °C to 10 °C respectively. The heat content per unit area in midsummer was found to vary with lake area. The local stability of stratification (N 2) varied by more than two orders of magnitude, declining with increasing latitude, altitude, and depth. The lakes can be classified according to morphometric and temperature characteristics, mixing depth, stability of stratification and glacial turbidity. Lago General Carrera (463 m) was found to be almost as deep as Lago Nahuel Huapi (464 m), which is considered to be the deepest lake in South America.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00877263
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  • 78
    Digitale Medien
    Digitale Medien
    Leaf surface compound fromBrassica oleracea (Cruciferae) induces oviposition byPieris brassicae (Lepidoptera: Pieridae) (1992)
    Springer
    Chemoecology 3 (1992), S. 39-44 
    Details
    ISSN: 1423-0445
    Schlagwort(e): oviposition ; kairomone ; host plant selection ; indole glucosinolates ; Cruciferae ; Brassica oleracea ; cabbage ; Lepidoptera ; Pieridae ; Pieris brassicae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Chemicals present on the surface of cabbage (Brassica oleracea L.) leaves were extracted by dipping these leaves for 3 s in dichloromethane followed by a 3 s dip in methanol. When offered in dual choice bioassays using green paper cards as a substrate, the methanol extract stimulated oviposition activity byPieris brassicae L. (Lepidoptera: Pieridae) females. The oviposition stimulant was isolated using medium pressure liquid chromatography, reversed-phase HPLC, ion-pair HPLC and ion exchange chromatography. Using1H-NMR spectroscopy, the stimulant could be identified as glucobrassicin (3-indolyl-methyl-glucosinolate). When pure glucobrassicin was offered at a dose identical to that in the crude methanol extract, butterflies did not discriminate between these two substrates in a dual choice test. It is argued that a high sensitivity for indole glucosinolates as host recognition factors may confer an adaptive value for these specialist crucifer feeders. The nutritional significance of their precursor tryptophan and the non-volatile nature of the aglycones formed upon enzymic hydrolysis in damaged tissues are proposed as properties of indole glucosinolates that contribute to this possible adaptive advantage.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01261455
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  • 79
    Digitale Medien
    Digitale Medien
    Pyrrolizidine alkaloids in overwintering monarch butterflies (Danaus plexippus) from mexico (1987)
    Springer
    Cellular and molecular life sciences 43 (1987), S. 943-946 
    Details
    ISSN: 1420-9071
    Schlagwort(e): Pyrrolizidine alkaloids ; macrocyclic diesters ; monoesters ; dihydropyrrolizines ; Lepidoptera ; Danaus plexippus ; monarch butterflies ; overwintering ; asteraceae ; Boraginaceae ; ecological chemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary North American populations of the monarch butterfly,Danaus plexippus, have been found to contain pyrrolizidine alkaloids and their N-oxides. Analytical methods (TLC, GC, and GC/MS) have been developed to isolate, quantitate, and structurally elucidate the alkaloids. Examples of at least two classes of pyrrolizidine alkaloids have been identified, the macrocyclic diesters, senecionine, integerrimine, and seneciphylline, and the monoesters, echinatine, intermedine, and lycopsamine.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01951680
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  • 80
    Digitale Medien
    Digitale Medien
    Chemical basis of pupal cannibalism in a caterpillar (Utetheisa ornatrix) (1992)
    Springer
    Cellular and molecular life sciences 48 (1992), S. 97-102 
    Details
    ISSN: 1420-9071
    Schlagwort(e): Lepidoptera ; Arctiidae ; pyrrolizidine alkaloids ; cannibalism ; acquired defense ; phagostimulation ; specific hunger
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract The mothUtetheisa ornatrix derives protection against predation from systemic pyrrolizidine alkaloids (PAs) that it sequesters as a larva from its foodplants (Leguminosae,Crotalaria spp.). We here show, in laboratory tests, thatUtetheisa deficient in body PA can make up for the chemical shortfall by cannibalizing pupae. We present evidence indicating that cannibalism in larvae is elicited not by hunger, but possibly by PA deficiency itself, and that in making cannibalistic choices larvae prefer PA-containing over PA-free pupae. PAs themselves, either in crystalline form or as additives to food items, proved phagostimulatory to larvae. In natureUtetheisa tend to pupate away from their foodplant, essentially out of reach of larval attack. The threat of cannibalism may have contributed to the evolution of this pupation behavior.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01923618
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  • 81
    Digitale Medien
    Digitale Medien
    The induction of secondary seed dormancy by oxygen deficiency in a barnyard grassEchinochloa crus-galli (1992)
    Springer
    Cellular and molecular life sciences 48 (1992), S. 904-906 
    Details
    ISSN: 1420-9071
    Schlagwort(e): Barnyard grass ; Echinochloa crus-galli ; oxygen deficiency ; seed dormancy ; soil seed bank ; stratification ; temperature
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract At 25°C, secondary dormancy was induced in seeds ofE. crus-galli exposed for 100 days to oxygen deficiency. By contrast, hypoxia did not induce dormancy at 15°C or prevent dormancy termination at 7°C. Secondary dormancy was terminated after 2 months stratification at 7°C. Oxygen deficiency may increase the proportion of dormant seeds in the soil, and affect the dynamics of the barnyard-grass soil seed bank.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02118432
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  • 82
    Digitale Medien
    Digitale Medien
    Evolutionary conservatism of oviposition preference in a widespread polyphagous insect herbivore, Papilio zelicaon (1997)
    Springer
    Oecologia 111 (1997), S. 209-215 
    Details
    ISSN: 1432-1939
    Schlagwort(e): Key words Insect-plant interactions ; Lepidoptera ; Polyphagy ; Specialization ; Host plant
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract We analyzed geographic differentiation in oviposition preference in the anise swallowtail butterfly, Papilio zelicaon Lucas, which is one of the most widely distributed and polyphagous butterflies in western North America. Among 13 populations that span 1200 km of the range of P. zelicaon in the Pacific Northwest of North America, the overall oviposition preference hierarchy has not diverged significantly, even though these populations differ in the plant species they use in the field. The results indicate that differences in host availability and use have not favored major reorganizations in the preference hierarchy of ovipositing females. Instead, this butterfly has a conserved preference hierarchy that varies within a narrow range among populations. All populations ranked the four test plant species in the same overall relative order, even though these populations differ in the plant species they use in the field.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004420050227
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  • 83
    Digitale Medien
    Digitale Medien
    Relative nutritional quality of C3 and C4 grasses for a graminivorous lepidopteran, Paratrytone melane (Hesperiidae) (1992)
    Springer
    Oecologia 92 (1992), S. 97-103 
    Details
    ISSN: 1432-1939
    Schlagwort(e): C3 and C4 grasses ; Lepidoptera ; Hesperiidae ; Paratrytone melane ; Nutrients
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary We tested the hypothesis that C4 grasses are inferior to C3 grasses as host plants for herbivorous insects by measuring the relative performance of larvae of a graminivorous lepidopteran, Paratrytone melane (Hesperiidae), fed C3 and C4 grasses. Relative growth rates and final weights were higher in larvae fed a C3 grass in Experiment I. However, in two additional experiments, relative growth rates and final weights were not significantly different in larvae fed C3 and C4 grasses. We examined two factors which are believed to cause C4 grasses to be of lower nutritional value than C3 grasses: foliar nutrient levels and nutrient digestibility. In general, foliar nutrient levels were higher in C3 grasses. In Experiment I, protein and soluble carbohydrates were digested from a C3 and a C4 grass with equivalent efficiencies. Therefore, differences in larval performance are best explained by higher nutrient levels in the C3 grass in this experiment. In Experiment II, soluble carbohydrates were digested with similar efficiencies from C3 and C4 grasses but protein was digested with greater efficiency from the C3 grasses. We conclude (1) that the bundle sheath anatomy of C4 grasses is not a barrier to soluble carbohydrate digestion and does not have a nutritionally significant effect on protein digestion and (2) that P. melane may consume C4 grasses at compensatory rates.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00317268
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  • 84
    Digitale Medien
    Digitale Medien
    Relationships between leaf age and the food quality of cottonwood foliage for the gypsy moth, Lymantria dispar (1987)
    Springer
    Oecologia 72 (1987), S. 527-532 
    Details
    ISSN: 1432-1939
    Schlagwort(e): Lepidoptera ; Salicaceae ; Herbivory ; Resource allocation ; Chemical defense
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The cottonwood tree, Populus deltoides, continues to produce leaves late into the growing season, exposing midseason herbivores to leaves of a wide range of maturity. Gypsy moth larvae preferred and grew best on the oldest cottonwood leaves and suffered higher mortality and 85% less growth when fed young, expanding leaves. Concentration of phenolics in the youngest leaves was 3 times that in the oldest leaves and was negatively correlated with caterpillar growth rate. The active phenolics were not identified; tannin was present but its concentration changed more with season than leaf age.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00378978
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  • 85
    Digitale Medien
    Digitale Medien
    Digestion of uncrushed leaf tissues by leaf-snipping larval Lepidoptera (1992)
    Springer
    Oecologia 89 (1992), S. 229-235 
    Details
    ISSN: 1432-1939
    Schlagwort(e): Lepidoptera ; Digestion ; Larvae ; Mandible ; C4 grasses
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Cynodon dactylon (Poaceae) leaf pieces recovered from the frass of final-instar Paratrytone melane larvae (Lepidoptera: Hesperiidae) were composed of 14–22 percent crushed cells and 78–86 percent uncrushed cells, yet approximate digestibilities of soluble carbohydrates and protein averaged 78 and 88 percent, respectively. Therefore, nutrients from uncrushed cells were extracted by P. melane. The ability of P. melane and another leaf-snipping lepidopteran, Pseudaletia unipuncta (Noctuidae), to digest the contents of uncrushed bundle sheath and mesophyll cells in C. dactylon was examined with transmission electron microscopy. Organelles and plasma membranes were digested in the foreguts and midguts of both species. These findings suggest that nutrients in uncrushed leaf cells may be extracted through plasmodesmata and cell wall pores after membranes are digested. The generality of leaf-snipping, vis-a-vis leaf crushing, among larval Lepidoptera was assessed by surveying the mandible morphologies of 202 species. In 82 percent of the species surveyed only incisor regions were present. I conclude that leaf-snipping is a common mode of feeding among phytophagous Lepidoptera and that the digestion of cell contents is efficient despite the fact that few of the cells of ingested plant tissues are crushed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00317222
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  • 86
    Digitale Medien
    Digitale Medien
    Anaerobic ammonia oxidation with nitrogen dioxide by Nitrosomonas eutropha (1997)
    Springer
    Archives of microbiology 167 (1997), S. 106-111 
    Details
    ISSN: 1432-072X
    Schlagwort(e): Key wordsNitrosomonas ; Anaerobic ammonia ; oxidation ; Anaerobic cell growth ; Nitrogen dioxide ; Nitric oxide ; Nitrous oxide ; Dinitrogen
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Nitrosomonas eutropha, an obligately lithoautotrophic bacterium, was able to nitrify and denitrify simultaneously under anoxic conditions when gaseous nitrogen dioxide (NO2) was supplemented to the atmosphere. In the presence of gaseous NO2, ammonia was oxidized, nitrite and nitric oxide (NO) were formed, and hydroxylamine occurred as an intermediate. Between 40 and 60% of the produced nitrite was denitrified to dinitrogen (N2). Nitrous oxide (N2O) was shown to be an intermediate of denitrification. Under an N2 atmosphere supplemented with 25 ppm NO2 and 300 ppm CO2, the amount of cell protein increased by 0.87 mg protein per mmol ammonia oxidized, and the cell number of N. eutropha increased by 5.8 × 109 cells per mmol ammonia oxidized. In addition, the ATP and NADH content increased by 4.3 μmol ATP (g protein)–1 and 6.3 μmol NADH (g protein)–1 and was about the same in both anaerobically and aerobically grown cells. Without NO2, the ATP content decreased by 0.7 μmol (g protein)–1, and the NADH content decreased by 1.2 μmol (g protein)–1. NO was shown to inhibit anaerobic ammonia oxidation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002030050422
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  • 87
    Digitale Medien
    Digitale Medien
    Determination of kerogen type by using DSC and TG analysis (1997)
    Springer
    Journal of thermal analysis and calorimetry 49 (1997), S. 745-753 
    Details
    ISSN: 1572-8943
    Schlagwort(e): DSC ; kerogen ; oxidation ; pyrolysis ; type determination
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract The rate of pyrolysis and oxidation of 8 different samples of oil shale kerogen concentrate (KC) were investigated using DSC analysis. Recently performed thermogravimetric studies (TG and DTG) with the same samples of KC indicated that the activation energy of the pyrolysis of specific KCs increases with increasing paraffinic structure in the KC. An opposite effect, i.e. a decrease of the activation energy with an increase of paraffinic structure was determined in the case of KC oxidation. In this study, using the standard ASTM E-698 method based on the determined temperature at which the maximum heat effect could be observed (exo in the case of oxidation and endo in the case of pyrolysis), an activation energy for the pyrolysis, as well as for the oxidation process was determined and also successfully correlated with the content of paraffinic structure of KC. Thus, the higher content of paraffinic structure in KCs indicates that higher values of the activation energy could be determined either in the case of pyrolysis or oxidation followed by DSC analysis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01996758
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  • 88
    Digitale Medien
    Digitale Medien
    Comparative studies on some analytical methods (1997)
    Springer
    Journal of thermal analysis and calorimetry 49 (1997), S. 857-862 
    Details
    ISSN: 1572-8943
    Schlagwort(e): analytical methods ; kinetics ; powder milk ; temperature
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract This work present comparative results on powder milk storage quality, obtained from analytical methods. Protein content was determined conventional (Kjeldahl) and colorimetric with biuret reagent at 540 nm and integral quality by thermogravimetric and biological methods. A method was developed for the protein separation of powder milk. Powder milk was submitted to degradation processes at 45, 60 and 80°C for 20 days. The results indicated that protein content values were inconsistent if determinations by Kjeldahl and colorimetric methods and biological tests were compared. There is evidence of thermal decomposition of powder milk as detected by biological and thermogravimetric methods.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01996770
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  • 89
    Digitale Medien
    Digitale Medien
    Using isothermal microcalorimetry for the prediction and testing of long-term properties of materials and products (1997)
    Springer
    Journal of thermal analysis and calorimetry 49 (1997), S. 1017-1023 
    Details
    ISSN: 1572-8943
    Schlagwort(e): degradation ; microcalorimetry ; moisture ; oxidation ; permeability
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract The use of isothermal microcalorimetry (MC) as a sensitive monitor for slow reactions is demonstrated in a number of examples. In Example 1 the spontaneous decomposition of a nitrate ester propellant is studied and the absolute degradation rate estimated. Example 2 illustrates how MC can be used for comparing the rate of oxidative ageing at different O2 concentrations. Synergetic effects between oxygen and moisture in accelerated ageing of nitrile rubber are evaluated from a so-called 4-point test in Example 3. The last example shows a simple MC technique for rapid determination of moisture permeability through a polymeric sealant.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01996789
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  • 90
    Digitale Medien
    Digitale Medien
    Thermal properties and reactivity determination of micro- and submicrometer nickel powders (1997)
    Springer
    Journal of thermal analysis and calorimetry 48 (1997), S. 657-664 
    Details
    ISSN: 1572-8943
    Schlagwort(e): nickel powders ; oxidation ; thermal analysis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract Monodispersed fine metal nickel powders of uniform shape and high purity are increasingly required for specific uses in many technological areas, especially in the preparation of electronic materials such as the manufacture of conductive inks and pastes and the formation of catalysts. Metallic nickel powders were prepared in ethylene glycol by the reduction of a nickel solution. Hydrazine was used as a reducing agent. Metal powders were characterized by chemical analysis, scanning electron microscopy (SEM), thermogravimetry (TG), derivative thermogravimetry (DTG) and differential scanning calorimetry (DSC). Particle size distributions were determined using laser light scattering. The reactivity and purity of these fine nickel powders were tested by repeated oxidation and reduction of nickel powders in oxidative and reductive atmospheres.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01979511
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  • 91
    Digitale Medien
    Digitale Medien
    Thermogravimetric studies of the synthesis of cas from gypsum, CaSo4·2H2O and phosphogypsum (1997)
    Springer
    Journal of thermal analysis and calorimetry 49 (1997), S. 1501-1507 
    Details
    ISSN: 1572-8943
    Schlagwort(e): calcium sulphide ; gypsum ; oxidation ; phosphogypsum ; reduction ; stability ; thermogravimetry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract Using a heating rate of 2°C min−1, CaS reacts with oxygen in air from 700°C to form CaSO4, with a complete conversion at 1100°C. Synthesis of CaS from the reaction between CaSO4 containing compounds and carbon compounds in air would not be possible, as the carbon reacts from 600°C with oxygen in the air to give CO2. Heating stoichiometric amounts of carbon and pure CaSO4, synthetic gypsum or phosphogypsum in a nitrogen atmosphere, results in the formation of CaS from 850°C. Using a heating rate of 10°C min−1, the formation of CaS is completed at 1080°C. Addition of 5% Fe2O3 as a catalyst lowers the starting temperature of the reaction to 750°C. Activation energy values at different fraction reaction values (α) differ between 340 and 400 kJ mol−1. The relationship between the activation energy values and conversion (α) indicates that the reaction proceeds via multiple steps.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01983709
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  • 92
    Digitale Medien
    Digitale Medien
    Low/high temperature relationships in dinitramide salts by DEA/DSC and study of oxidation of aluminum powders by DSC/TG (1997)
    Springer
    Journal of thermal analysis and calorimetry 49 (1997), S. 1161-1170 
    Details
    ISSN: 1572-8943
    Schlagwort(e): basicity ; dinitramides ; kinetics ; oxidation ; tanδ ; transition temperatures
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract The dinitramide salts of ammonia (ADN), hexamethylenetetramine (HDN), potassium (KDN), and sodium (NaDN) showed a linear relationship between the DSC rate of decomposition at the peak maximum and the DEA tanδ value at the low temperature transition peak. As the cation basicity increased in the series ADN〈HDN〈KDN〈NaDN, there was an increase in the low temperature transition peak, the energy barrier for relaxation, and the decomposition peak temperature, and a decrease in the tanδ value at the low temperature transition peak, specific heat capacity, and the rate and enthalpy of decomposition. The more basic salts were more thermally stable (i.e., higher decomposition temperature) and less energetic (i.e., lower enthalpy of decomposition). The more internal free volume (disorder) present in these salts, the higher the rates of relaxation and decomposition. Five aluminum powders of different surface areas were analyzed by DSC in platinum sample pans, and it was found that the enthalpy and rate of oxidation increased as the particle size of Al decreased while the enthalpy of the Al melt decreased. TG showed a two-step weight gain in the oxidation of Al with plateaus in the 650 and 1130°C regions and the percent weight gain increased as the particle size of Al decreased. Variable DSC and TG heating rate studies showed that the activation energies for the first step in the oxidation process increased as the particle size of Al increased.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01983671
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  • 93
    Digitale Medien
    Digitale Medien
    Measurement by LASER-Generated Ultrasound of Four Stiffness Coefficients of an Anisotropic Material at Elevated Temperatures (1997)
    Springer
    Journal of nondestructive evaluation 16 (1997), S. 91-100 
    Details
    ISSN: 1573-4862
    Schlagwort(e): LASER ultrasound ; anisotropic material ; group velocity ; stiffness coefficients ; temperature
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Elektrotechnik, Elektronik, Nachrichtentechnik , Mathematik
    Notizen: Abstract Ultrasonic waves are generated through a composite material by means of a noncontact technique. It uses a Nd:Yag LASER for the generation and an interferometric probe for the detection of acoustic waveforms. From a suitable set of experimental data, an inversion scheme is used for the recovering of four stiffness coefficients. They characterize the elasticity in a principal plane of symmetry of the material which exhibits an orthorhombic symmetry. The measurements are performed at various temperatures, elevated by steps up to 300°C for two specimen. The sensitivity of the method appears convenient to measure the temperature induced stiffness changes. The anisotropic degradation of the material properties are then pointed out.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1022620501899
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  • 94
    Digitale Medien
    Digitale Medien
    Reaction of water vapor and oxygen with liquid uranium (1987)
    Springer
    Oxidation of metals 28 (1987), S. 195-211 
    Details
    ISSN: 1573-4889
    Schlagwort(e): Uranium ; corrosion ; oxidation ; liquid metal
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Maschinenbau
    Notizen: Abstract The reactions of water vapor and oxygen with liquid uranium were studied by modulated molecular-beam mass spectrometric methods. Equivalent pressures of the reactant fluxes on the surface ranged from 6×10 −6 to 2×10−4 torr. Temperatures up to 1570 K were investigated. The metal surface was kept clean during reaction by mechanical removal of the oxide formed with a tungsten needle. For the clean liquid uranium surface, a water reaction probability of ∼0.4 was deduced both from measurement of the reaction-product hydrogen signal and by the temperature dependence of the scattered reactant signal. Based solely on the latter measure, a reaction probability of 0.6 was estimated for oxygen. The reaction probabilities on the clean surface were temperatureindependent. They decreased as the coverage of the surface by islands of oxide increased and, for water, appeared to approach a value of 0.08 for a surface completely covered with an oxide estimated to be 500 Å thick. Bombardment of the surface during reaction with argon ions produced an increase in the reactivity on solid uranium but had a negligible effect on the reaction probability for the liquid.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00656707
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  • 95
    Digitale Medien
    Digitale Medien
    Evolution of grain structure in nickel oxide scales (1987)
    Springer
    Oxidation of metals 28 (1987), S. 353-389 
    Details
    ISSN: 1573-4889
    Schlagwort(e): Grain growth ; nickel oxide ; high temperature ; oxidation ; nickel
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Maschinenbau
    Notizen: Abstract In systems such as the oxidation of nickel, in which grain-boundary diffusion in the oxide can control the rate of oxidation, understanding of the factors governing the grain structure is of importance. High-purity mechanically polished polycrystalline nickel was oxidized at 700°C, 800°C, and 1000°C for times up to 20 hr in 1 atm O2. The scale microstructures were examined by parallel and transverse cross section transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Texture coefficients were found by X-ray diffraction (XRD). Each grain in the transverse section grain boundary networks was systematically analyzed for width parallel to the Ni-NiO interface and perpendicular length, for boundary radius of curvature and for number of sides. The variation of these parameters with depth in the scale was examined. In particular, grains were increasingly columnar (i.e., with ratio of grain length to width 〉1) at higher temperatures and longer times. Columnar grain boundaries tended to be fairly static; the columnar grain width was less than the rate controlling grain size predicted from the oxidation rate. The mean boundary curvature per grain provided a guide to the tendency for grain growth, except in the region of the Ni-NiO interface, where the boundaries were thought to be pinned.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00666728
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  • 96
    Digitale Medien
    Digitale Medien
    Oxidation behavior of several chromia-forming commercial nickel-base superalloys (1997)
    Springer
    Oxidation of metals 47 (1997), S. 381-410 
    Details
    ISSN: 1573-4889
    Schlagwort(e): Ni-Base superalloys ; Astroloy ; Waspaloy ; Udimet 720 ; oxidation ; chromia
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Maschinenbau
    Notizen: Abstract Several commercially available Ni-base superalloys were exposed isothermally in air at temperatures between 750° and 1000°C and also under cyclic conditions at 1000°C. The kinetics of oxidation were determined and the scales were analyzed by electron microscopy and X-ray diffraction. Thin adherent chromia-rich scales formed on the alloys at 750°C after 1000 hr. Although Waspaloy showed the lowest weight gain in this test, it also showed the deepest internal corrosion due to oxidation of the grain-boundary carbides. At temperatures up to 1000°C the external scales were also chromia-rich but there was greater internal corrosion. Titanium in the alloys oxidized, diffusing through the chromia scale to form faceted rutile (TiO2) grains at the surface as well as forming TiO2 and TiN internally. The amount of rutile at the oxide surface increased with temperature and alloy Ti concentration. Alumina formed as discrete internal oxides below the chromia scale, although Astroloy when oxidized isothermally at 1000°C developed a semicontinuous internal layer of alumina due to its higher Al content. Under cyclic conditions Astroloy formed a thicker, less-protective scale of transition oxides probably due to its lower Cr content.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02134783
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  • 97
    Digitale Medien
    Digitale Medien
    Oxidation behavior of an Fe-38Ni-13Co-4.7Nb-1.5Ti-0.4Si superalloy at high temperature in Ar-H2O atmospheres (1997)
    Springer
    Oxidation of metals 47 (1997), S. 411-426 
    Details
    ISSN: 1573-4889
    Schlagwort(e): oxidation ; Incoloy 909 ; superalloy ; scale ; high temperature ; kinetics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Maschinenbau
    Notizen: Abstract The oxidation of an Fe-38Ni-13Co-4.7Nb-1.5Ti-0.4Si superalloy (Incoloy 909 type alloy), was investigated at temperatures between 1000 K and 1400 K in Ar-(1, 10%)H20 atmosphere using metallographic, electron probe microanalysis, and X-ray diffraction techniques. The oxide scales consist of an external scale and an internal scale which has an intergranular scale (above 1200 K) and an intergranular scale. The oxide phases in each scale are identified asα-Fe2,O3 (below 1200 K) or FeO (above 1300 K) and CoO · Fe2O3 and FeO · Nb2O5, respectively. The morphologies, the oxide phases and the oxidation rates do not depend on the partial pressure of H2O in the range between one and ten percent in Ar gas. The rate constants for the intergranular-scale formation in this alloy are about one-tenth as large as those in Fe-36%Ni alloy reported previously. At all the temperatures the scales grow according to a parabolic rate law and the apparent activation energies for the processes are estimated.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02134784
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  • 98
    Digitale Medien
    Digitale Medien
    Water-vapor-effect on the oxidation of Fe-21.5 wt.%Cr-5.6 wt.%Al at 1000°C (1997)
    Springer
    Oxidation of metals 47 (1997), S. 445-464 
    Details
    ISSN: 1573-4889
    Schlagwort(e): oxidation ; Fe-Cr-Al alloy ; water vapor ; ESCA ; RHEED
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Maschinenbau
    Notizen: Abstract Fe-21.5 wt. %Cr-5.6 wt. %Al oxidation, at 1000°C, in dry or wet oxygen shows that steam has an influence on the oxide-scale growth mechanism. Steam modifies the kinetics of early-stage oxidation. In dry oxygen, an initial fast linear regime is observed during one hour. Under wet conditions, weight-gain curves follow the same parabolic regime over the entire oxidation test. The scale structure strongly depends on the presence of steam in the gaseous environment. With dry oxygen, the scale is composed mainly ofα-Al2O3 after the initial formation ofγ-Al2O3 identified by ESCA and RHEED. The kinetics transient stage corresponds to the necessary time for the internal part of the initialγ-Al2O3 scale to transform into a continuousα-Al2O3 diffusion barrier. Under wet oxygen conditions, transient oxides are identified as (Mg, Fe) (Cr, Al)2O4, MgAl2O4 (orthorhombic), Al2O3 (hexagonal), these oxides transform into MgAl2O4 (cubic), Cr3O4, Fe2O3,α-Al2O3, with time. When water vapor does not change drastically oxidation kinetics, the induced presence of iron and chromium in the oxide scale could be responsible for weakening the protectiveness of alumina scales.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02134786
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  • 99
    Digitale Medien
    Digitale Medien
    The transient state in the oxidation of binary alloys forming the most-stable oxide: A numerical solution (1997)
    Springer
    Oxidation of metals 47 (1997), S. 507-524 
    Details
    ISSN: 1573-4889
    Schlagwort(e): alloys ; high temperature ; oxidation ; transient state
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Maschinenbau
    Notizen: Abstract The initial transient high-temperature oxidation stage for binary alloys forming the most-stable oxide has been examined by means of a numerical procedure based on the finite-difference method. At variance with previous models, the present treatment takes into account the effect of the rate of the reaction at the scale/gas interface over the corrosion kinetics. The calculations concerning the transient stage are developed either using the general parabolic rate law to represent the overall scaling kinetics or using the rate law of the reaction at the scale/gas interface as a boundary condition without imposing any particular rate law to the overall process. A correct analysis of the oxidation behavior of binary alloys during the transient stage must take into account the kinetics effect of the rate of the surface reaction. The concentration of the most-reactive element at the alloy/scale interface changes regularly with time, decreasing gradually from the initial bulk value to its final steady-state value. The present results are in good agreement with those obtained by means of an approximate analytical model developed previously.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02134789
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  • 100
    Digitale Medien
    Digitale Medien
    An approximate treatment of the transient state in the oxidation of binary alloys forming the most-stable oxide. Part II: Single-phase alloys in systems with a solubility gap (1997)
    Springer
    Oxidation of metals 47 (1997), S. 525-550 
    Details
    ISSN: 1573-4889
    Schlagwort(e): high temperatures ; oxidation ; transient state
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Maschinenbau
    Notizen: Abstract The transient state in the oxidation of solid solutions of a most-noble componentA in a most-reactive componentB (beta phase) for binaryA-B alloys presenting a limited reciprocal solubility of the two metals has been examined assuming that theirB content is sufficient for the exclusive growth of externalBO scales. Above a criticalB content of the alloy theBO scales may grow directly on the surface of the beta phase, while below this limit they can only form over a layer ofB-depleted solid solution ofB inA (alpha phase), which appears after a critical time. An approximate analytical expression for the profile of concentration ofB in the alloy has been adopted to calculate the flux ofB in the metal. Moreover, the effect of the reaction between the gas and the external oxide surface has been taken into account using a procedure developed by Wagner for the oxidation of pure metals. The corrosion kinetics as well as all the parameters involved, such as the concentration ofB at the alloy-scale interface, have been calculated as functions of the corrosion time. The results show that, as time proceeds, the instantaneous parabolic rate constant increases and the concentration ofB at the alloy-scale interface decreases, both tending gradually to their corresponding steady-state values. It is also predicted that if the rate of transformation of the beta phase in the alpha phase after the alloy reaches the composition of equilibrium at the interface with the oxide is lower than the corresponding rate of displacement of the alloy surface due to scale growth, the corrosion of beta phase alloys may eventually lead to the formation of two phase mixtures of alpha phase andBO which are expected to grow at much larger rates than in the presence of a uniform continuous alpha layer.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02134790
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