ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Aerodynamics
  • Ecology
  • 1985-1989  (73)
  • 1950-1954  (76)
  • 1935-1939  (15)
  • 1
    Electronic Resource
    Electronic Resource
    Aerodynamics of Ephedra trifurca (1986)
    Springer
    Journal of mathematical biology 24 (1986), S. 1-24 
    Details
    ISSN: 1432-1416
    Keywords: Aerodynamics ; Pollination ; Ephedra ; Computer simulations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Mathematics
    Notes: Abstract Computer simulations are used to predict the behavior of pollen grains with different physical properties within the acceleration field created around the ovules of the gymnosperm Ephedra trifurca. A modelling procedure is given that (1) calculates the number of pollen grains captured by an ovule's pollination-droplet and (2) gives a correlation between pollination efficiency and the physical properties (= mass, size) of different types of pollen. Based on this procedure, the number of Ephedra pollen grains captured by micropyles can be less than the number captured from other species. However, the mass and size of Ephedra pollen grains appear to coincide with those predicted to yield a local maximum of pollination efficiency, i.e. slightly larger or smaller values of either mass or size would decrease the probability of capture. In addition, the properties of Ephedra pollen grains operate synergistically in the aerodynamic environment around ovules and are focused to collide with pollination-droplets. By analogy, the properties of Ephedra pollen coincide with those predicted for a localized “adaptive peak”. The physical properties of pollen grain types other than E. trifurca that can maximize pollen capture are not generally represented in the aerobiology of Ephedra during the pollination season. Therefore, the phenology of pollen release, community taxonomic-composition, and the physics of particle capture play collectively important roles in the reproductive success of Ephedra trifurca.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00275718
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    A rotational groups system approach for interdisciplinary research (1989)
    Springer
    Environmental management 13 (1989), S. 425-433 
    Details
    ISSN: 1432-1009
    Keywords: Interdisciplinarity ; Small islands ; Aeolian project ; Ecology ; Economy ; Human factors ; Environmental research methodology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Environmental research is characterized in each of its successive phases by a strong interdisciplinarity. A rotational groups system (RGS) method is proposed as an instrument to encourage interaction among researchers from fields that are traditionally far apart. Meetings conducted with the RGS procedure involve all the researchers, who, in repeated and topical encounters, are able to exchange information on a wide variety of environmental subjects. These meetings can be arranged according to a special calendar, through a series of phases treating different aspects of the same subjects to be discussed, and above all, referring to specific “themes” and “working guidelines” organized on the basis of criteria designed to favor an exchange of ideas and constructive discussion. At the end, the plenary assembly edits an overall resume of the proceedings, and votes on the final resolution, which brings together all the conclusive opinions regarding the themes discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01867676
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Towards a science of sustainable upland management in developing countries (1989)
    Springer
    Environmental management 13 (1989), S. 43-54 
    Details
    ISSN: 1432-1009
    Keywords: Sustainable development ; Ecology ; Agroecosystems ; Field research ; Statistical reliability ; Southeast Asia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Farmers attempting to subsist in tropical uplands often rely upon unsustainable resource use practices that lead to soil erosion, declining crop yields, and a loss of soil productivity capacity. Other uses of tropical uplands, including logging and conversion of forest to rangelands, have similar results. The undesirable effects of these actions are felt on-site, at the watershed level, and even nationally. Ecological cause-effect relationships are poorly understood, and few examples exist of the successful integration of ecological knowledge with upland development. It is hypothesized that recent results of ecological research could be applied to uplands management so that stable sustainable systems of human use may be established. A second hypothesis is that statistically reliable data can be obtained from experiments in upland situations, although natural variations of soils, weather, and vegetation are great. To test these hypotheses, research involving multinational collaboration among American and Southeast Asian scientists has begun. The objective of the work is to provide credible quantitative information to help policy and decision makers and resident farmers to plan and implement improved practices based on ecological principles. Some findings to date include: 1. Ecological principles are difficult to relate to the practical context of upland agroecosystems. Indeed, the null hypothesis is necessary for planning experiments and demonstrations. 2. The “signal-to-noise” ratio in these field experiments is low, and the detection of changes due to human intervention in soil erosion, nutrient movement, and plant productivity is difficult. 3. Obstacles to field research in developing countries include logistic, cultural, political, and institutional factors. It is essential that local land managers participate from the start with scientific researchers in designing experiments. 4. Planned collaboration among academic and government scientists facilitates design of relevant research and the implementation of results. 5. The idea of ecologically based management has been well received by researchers and government officials in Asia. There is little argument with the logic of the approach. 6. Pressures for quick responses to urgent problems in the uplands conflict with the need for careful, long-term, statistically valid scientific research. 7. Ecological principles are vaguely understood and poorly articulated in the scientific literature. The transfer and application of ecological science to the developing world would be enhanced by clearer statements of principles.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01867586
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Anaerobic biotransformations of pollutant chemicals in aquifers (1988)
    Springer
    Journal of industrial microbiology and biotechnology 3 (1988), S. 179-194 
    Details
    ISSN: 1476-5535
    Keywords: Aquifer ; Biodegradation, anaerobic ; Pollutant ; Groundwater ; Methanogenesis ; Sulfate-reduction ; Ecology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary Anaerobic microbial communities sampled from either a methanogenic or sulfate-reducing aquifer site have been tested for their ability to degrade a variety of groundwater pollutants, including halogenated aromatic compounds, simple alkyl phenols and tetrachloroethylene. The haloaromatic chemicals were biodegraded in methanogenic incubations but not under sulfate-reducing conditions. The primary degradative event was typically the reductive removal of the aryl halides. Complete dehalogenation of the aromatic moiety was required before substrate mineralization was observed. The lack of dehalogenation activity in sulfatereducing incubations was due, at least in part, to the high levels of sulfate rather than a lack of metabolic potential. In contrast, the degradation of cresol isomers occurred in both types of incubations but proved faster under sulfate-reducing conditions. The requisite microorganisms were enriched and the degradation pathway forp-cresol under the latter conditions involved the anaerobic oxidation of the aryl methyl group. Tetrachloroethylene was also degraded by reductive dehalogenation but under both incubation conditions. The initial conversion of this substrate to trichloroethylene was generally faster under methanogenic conditions. However, the transformation pathway slowed when dichloroethylene was produced and only trace concentrations of vinyl chloride were detected. These results illustrate that pollutant compounds can be biodegraded under anoxic conditions and a knowledge of the predominant ecological conditions is essential for accurate predictions of the transport and fate of such materials in aquifers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01569525
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    On the ecology of ciliates in riverwaters: The evaluation of water quality via ciliates and filamentous bacteria (1989)
    Springer
    Aquatic sciences 51 (1989), S. 235-248 
    Details
    ISSN: 1420-9055
    Keywords: Ecology ; ciliates ; river ; water quality ; sphaerotilus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Since sewage treatment plants are most effective in Switzerland, the micro-benthic communities in receiving running waters have changed considerably. From January 1980 to September 1981 the periphyton communities in 13 Swiss streams and rivers were monthly investigated. The NH4-N concentration in these waters varied between 0.015 and 1.0 mg/l. Four typical communities of microorganisms were found: In unpolluted running waters mainly small vagile ciliates were abundant; in slightly polluted waters peritricha (in the presence of bacteria) were found; in moderatly polluted waters peritricha in combination of few hymenostomata and Sphaerotilus could grow when bacteria and some degredable organic material where present; in polluted waters the well-known Spaerotilus-community (after Liebmann) could be found. The microscopic as well as the macroscopic aspect should be considered to qualify the degree of pollution in streams and rivers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00877745
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Effects of noise on some dynamical models in ecology (1986)
    Springer
    Journal of mathematical biology 24 (1986), S. 479-523 
    Details
    ISSN: 1432-1416
    Keywords: Nonlinear dynamics ; Noise ; Chaos ; Ecology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Mathematics
    Notes: Abstract We investigate effects of random perturbations on the dynamics of one-dimensional maps (single species difference equations) and of finite dimensional flows (differential equations for n species). In particular, we study the effects of noise on the invariant measure, on the “correlation” dimension of the attractor, and on the possibility of detecting the nonlinear deterministic component by applying reconstruction techniques to the time series of population abundances. We conclude that adding noise to maps with a stable fixed-point obscures the underlying determinism. This turns out not to be the case for systems exhibiting complex periodic or chaotic motion, whose essential properties are more robust. In some cases, adding noise reveals deterministic structure which otherwise could not be observed. Simulations suggest that similar results hold for flows whose attractor is almost two-dimensional.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00275681
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Exogenous inorganic carbon sources for photosynthesis in seawater by members of the Fucales and the Laminariales (Phaeophyta): ecological and taxonomic implications (1989)
    Springer
    Oecologia 78 (1989), S. 97-105 
    Details
    ISSN: 1432-1939
    Keywords: Phacophyta ; Inorganic carbon assimilation ; Carbonic anhydrase ; Carbon dioxide compensation concentration ; Ecology ; Taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Characteristics of inorganic carbon assimilation by photosynthesis in seawater were investigated in six species of the Fucales (five Fucaceae, one Cystoseiraceae) and four species of the Laminariales (three Laminariaceae, one Alariaceae) from Arbroath, Scotland. All of the algae tested could photosynthesise faster at high external pH values than the uncatalysed conversion of HCO 3 - to CO2 can occur, i.e. can “use” external HCO 3 - . They all had detectable extracellular carbonic anhydrase activity, suggesting that HCO 3 - use could involve catalysis of external CO2 production, a view supported to some extent by experiments with an inhibitor of carbonic anhydrase. All of the algae tested had CO2 compensation concentrations at pH 8 which were lower than would be expected from diffusive entry of CO2 supplying RUBISCO as the initial carboxylase, consistent with the operation of energized entry of HCO 3 - and / or CO2 acting as a “CO2 concentrating mechanism”. Quantitative differences among the algae examined were noted with respect to characteristics of inorganic C assimilation. The most obvious distinction was between the eulittoral Fucaceae, which are emersed for part of, or most of, the tidal cycle, and the other three families (Cystoseiraceae, Laminariaceae, Alariaceae) whose representatives are essentially continually submersed. The Fucaceae examined are able to photosynthesise at high pH values, and have lower CO2 compensation concentrations, and lower K1/2 values for inorganic C use in photosynthesis, at pH 8, than the other algae tested. Furthermore, the Fucaceae are essentially saturated with inorganic C for photosynthesis at the normal seawater concentration at pH 8 and 10°C. These characteristics are consistent with the dominant role of a “CO2 concentrating mechanism” in CO2 acquisition by these plants. Other species tested have characteristcs which suggest a less effective HCO 3 - use and “CO2 concentrating mechanism”, with the Laminariaceae being the least effective; unlike the Fucaceae, photosynthesis by these algae is not saturated with inorganic C in normal seawater. Taxonomic and ecological implications of these results are considered in relation to related data in the literature.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00377203
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Population biology of two land snails (Mesomphix spp.): variation among six southern appalachian sites with differing disturbance histories (1989)
    Springer
    Oecologia 79 (1989), S. 372-382 
    Details
    ISSN: 1432-1939
    Keywords: Logging disturbance ; Land gastropods ; Ecology ; Genetics ; Population
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Ecological and genetic properties of two North American terrestrial gastropods (Mesomphix spp.) were characterized in paired control and previously logged watersheds in two North Carolina forests (Coweeta and the Great Smoky Mountains National Park) of the Southern Appalachian Biosphere Reserve Cluster. Shell growth was greater in the control sites, but density and mortality were largely independent of prior logging history and forest reserve. Based on starch gel electrophoresis data, both species showed their highest levels of genetic diversity in the Coweeta forest, the component of the reserve cluster which had the most extensive and variable history of logging disturbance. M. subplanus also exhibited higher levels of heterozygosity in logged than in control watersheds, and M. andrewsae showed over twice as many rare alleles in disturbed sites as in control sites. F-statistic analysis depicted both excess levels of homozygosity and moderate genetic differentiation among the populations, reflecting the effects of small population size and perhaps drift and inbreeding. Estimated gene flow was relatively low. These results correspond to the recent finding by Bryant et al. (1987) and others on the effects of bottlenecks, and to the contrasting history of habitat instability of the two major study forests.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00384317
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Scatter-and clump-dispersal and seedling demography: hypothesis and implications (1989)
    Springer
    Oecologia 79 (1989), S. 417-426 
    Details
    ISSN: 1432-1939
    Keywords: Demography ; Ecology ; Frugivory ; Seed dispersal ; Tropics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Fruit-eating animals deposit viable seeds in patterns that determine the conditions under which seeds and seedlings live or die. Many tree species are scatter-dispersed by birds, bats, or other small frugivores that regurgitate, defecate, or drop seeds singly or in pairs. These scatterdispersed plant species normally recruit as isolated individuals, and are unlikely to evolve exceptional resistance to herbivores, pathogens, or to other sources of density-dependent seed or seedling mortality. Other tree species are clump-dispersed by larger terrestrial or arboreal frugivores that defecate seeds in masses which produce bouquets of seedlings. Because their seeds invariably germinate in close proximity to other seedlings, clump-dispersed species necessarily evolve chemical or mechanical defenses against seed predators, pathogens, and herbivores that act in a densitydependent manner. Population and genetic attributes should reflect this basic dichotomy in the conditions of seedling recruitment. I predict that seedlings of scatter-dispersed species rarely survive near parents or in dense aggregations under frugivore roosts. Seed dispersal should be mandatory, often to light gaps or other special habitats. Outbred adults and juveniles are expected to exist at low densities in loose aggregations or random distributions. Seedlings of clump-dispersed trees are pre-adapted for survival in dense aggregations near parents, as well as in fecal clumps. Substantial recruitment of juveniles and young adults should occur from undispersed seeds under and near parent trees. Such species should be common, highly aggregated, and show strong genetic family structure. Because recruitment requires dispersal, scatter-dispersed plant species should be especially vulnerable to loss of dispersal agents. Because offspring consistently recruit near parents, clump-dispersed plants should be less vulnerable to temporary loss of dispersal agents.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00384323
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    The fishery, biology, and management of Atlantic sturgeon, Acipenser oxyrhynchus, in North America (1985)
    Springer
    Environmental biology of fishes 14 (1985), S. 61-72 
    Details
    ISSN: 1573-5133
    Keywords: Acipenseridae ; Life history ; Ecology ; Harvest ; Culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis The Atlantic sturgeon supported major fisheries along the entire Atlantic coast of North America. These fisheries peaked about 1890 and then suffered almost total collapse by 1905. The Atlantic sturgeon is anadromous and highly susceptible to capture during spawning migrations. Further, this species biological characteristics makes it very vulnerable to man-induced changes in natural habitat and slow to recover. Atlantic sturgeon mature at an advanced age (7–27 year for females, depending on latitude), exhibit a long interspawning period (2–5 year), and require suitable riverine, estuarine, and coastal environments for successful completion of their life cycle. Today, only remnant stocks exist in areas of former abundance. Management regulations vary considerably from state to state and range from full protection to no protection. Biological data are needed to: identify and characterize specific spawning and nursery areas; delineate migratory patterns and recruitment to various stocks; establish stock abundance; and, assess effects of various management strategies. In order to protect remaining stocks, the imposition of a total harvesting moratorium is recommended.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00001577
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 11
    Electronic Resource
    Electronic Resource
    Early ontogeny of Adinia xenica (Pisces, Cyprinodontiformes): 3. Comparison and evolutionary significance of some patterns in epigenesis of egg-scattering, hiding and bearing cyprinodontiforms (1986)
    Springer
    Environmental biology of fishes 15 (1986), S. 91-105 
    Details
    ISSN: 1573-5133
    Keywords: Fish epigenesis ; Ecology ; Evolution ; Embryonic arrest ; Hatching initiation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis Developmental patterns as seen in cyprinodontiforms fishes with different reproductive styles are compared, and discussed in relation to ecology and evolutionary significance. The discussion centres around Adinia xenica (its detailed ontogeny presented in two previous sequels to this paper), and, from the existing literature, Fundulus heteroclitus (closely related), Austrofundulus myersi (an annual) and Platypoecilus maculatus (a livebearer). The embryonic resting interval is present in various forms in the first three species, and differences in it and the overall patterns of development are shown to be consistent with ecological conditions. Termination of the resting interval leads immediately to hatching, a process in A. xenica, as in F. heteroclitus, apparently initiated by the appropriate summation of internal and external factors. These factors include any or all of: metabolic changes and increased oxygen requirements, response to light, reduced environmental oxygen, agitation, and increased hydrostatic pressure. They all can cause increased movement by the embryo which is credited with rupturing hatching gland cells and releasing the enzyme(s). Annual fishes experience 3 pronounced resting intervals, termed diapauses. These are discussed in the context of apparent steps and thresholds, and evolutionary ecology. A possible evolutionary sequence, from a simple fractional spawning pattern to diapause, is presented. Morphological differences in primary embryonic respiratory surfaces, as seen in the four species, are related to environmental conditions. The above illustrate ways in which the same basic structures and events are modified to cope with different habitats.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00005425
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 12
    Electronic Resource
    Electronic Resource
    Temporal and areal feeding behavior of the butterflyfish,Chaetodon trifascialis, at Johnston Atoll (1989)
    Springer
    Environmental biology of fishes 25 (1989), S. 187-193 
    Details
    ISSN: 1573-5133
    Keywords: Foraging ; Ethology ; Ecology ; Chaetodontid ; Territorial ; Corallivore ; Corals ; Reef
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis The chevron butterflyfish,Chaetodon trifascialis, is found throughout the Indo-Pacific. It is a territorial, diurnal, corallivore found in close association withAcropora spp. corals. The feeding behavior of 33 individuals was studied over six seasons in three habitats.Chaetodon trifascialis spent one third of its active time feeding. However, there was much individual variation. Fish had significantly higher feeding rates during the early afternoon, and there were no significant differences in the feeding rates between the seasons. Feeding rates were significantly different between the three habitats. TheMontipora-rich habitat had the highest feeding rates (x = 10.74 bites min-1 ± 0.87, all corals combined) and theAcropora-Montipora mixed habitat had the lowest feeding rates (x = 4.58 bites min-1 ± 0.63, all corals combined). Females fed significantly more than males. WhileC. trifascialis had been thought to only eatAcropora spp. corals, it occasionally fed onMontipora spp. andPocillopora sp. corals whenAcropora spp. were scarce.Chaetodon trifascialis exhibited patterns predicted by foraging theory of an energy maximizer. Territory sizes were inversely related to food density and feeding rates were inversely related to intruder rates. This is a promising system for future testing of foraging strategy models.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00002211
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 13
    Electronic Resource
    Electronic Resource
    Non-visual feeding behavior of the mottled sculpin, Cottus bairdi, in Lake Michigan (1985)
    Springer
    Environmental biology of fishes 12 (1985), S. 111-117 
    Details
    ISSN: 1573-5133
    Keywords: Benthos ; Ecology ; Feeding periodicity ; Great Lakes ; Lateral line ; Mechanoreception ; Predation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis Field and laboratory experiments indicate that the mottled sculpin, Cottus bairdi, feed in the dark. Blinded sculpins feed on a variety of motile prey in the laboratory and show stereotyped responses to prey stimuli. The sculpins bite at moving inert objects, even if buried in substratum, indicating that they use their lateral line system to detect prey. Covering portions of the lateral line with an inert paste eliminates response to objects near the covered region of the lateral line. The sculpins can also detect prey (including inert objects) in a stream if the prey is upstream. Collection from two series of presunset, postsunset, presunrise, postsunrise, dives in Lake Michigan indicate nocturnal feeding by the mottled sculpin.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00002763
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 14
    Electronic Resource
    Electronic Resource
    Microgeographic diversity in the neotropical knife-fish Eigenmannia macrops (Gymnotiformes, Sternopygidae) (1985)
    Springer
    Environmental biology of fishes 13 (1985), S. 173-181 
    Details
    ISSN: 1573-5133
    Keywords: Evolution ; Ecology ; Morphometrics ; Morphology ; Electroreception ; Orinoco River ; Venezuela
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis Examination of 681 individuals of electric knife-fishes, Eigenmannia macrops, from the Orinoco River, Venezuela, revealed a pattern of morphological diversity which covaried with habitat. Fishes from the caños (small stream tributaries) are on average smaller than those from offshore habitats and lagoons. Even at the same body size the tails of caño fishes are relatively shorter, their bodies are deeper, and their heads are relatively wider than those from other habitats. Caño fishes are more different from fishes of the deep channels than from those of the shallow channels, beaches, or lagoons. Several factors are examined for their possible relationship to the origin of the observed diversity including electrophysiology, locomotory adaptation, growth rate and ecology. The problems of genetic versus physiological bases of morphological variation are addressed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00000928
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 15
    Electronic Resource
    Electronic Resource
    Development of dietary specializations in a summer community of juvenile fishes (1985)
    Springer
    Environmental biology of fishes 13 (1985), S. 211-224 
    Details
    ISSN: 1573-5133
    Keywords: Competition ; Food resources ; Habitat ; Ontogeny ; Ecology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis Patterns of food use and food availability were analysed in a species rich summer weedbed community of juvenile lake fish to elucidate ontogenetic and ecological adaptations facilitating species co-existence and rapid growth. It was found that: (a) the community was based on the period of high seasonal invertebrate abundance linked to the spring-summer proliferation of macrophytes: food was not limiting; (b) diet separations of individual fish species were high. In mid-July when nine species were present, Schoener diet overlap values exceeded 0.25 in only ten of 36 pairs of combinations. This contrasted with findings from a preceding May-June community of larval fish (Keast 1980); (c) mouth size helped channel the species towards different diets; and (d) diets of the early juveniles were distinct from those of the larvae, and late juveniles and adults of their species. At both the species and community level, ontogenetic and ecological developments have evolved in response to the opportunities created by an annually repetitive resource base.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00000933
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 16
    Electronic Resource
    Electronic Resource
    The influence of diel cycle, tidal direction and trawl alignment on beam trawl catches in an equatorial estuary (1987)
    Springer
    Environmental biology of fishes 19 (1987), S. 297-308 
    Details
    ISSN: 1573-5133
    Keywords: Ecology ; Fish ; Leiognathids ; Mangroves ; Nekton ; Papua New Guinea ; Periodicity ; Prawns ; Tidal cycles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis Using a 3 m beam trawl, catch variation in the fish and prawn assemblage of the Labu estuary, Papua New Guinea was investigated during July and December 1981 and September 1984. About six times more organisms, three and a half times the biomass and twice as many species were caught per trawl at night than during the day. The greatest number of species, individuals and biomass were caught just after dusk. With the exception ofSecutor ruconius, there was no significant difference in the catches trawled at ebbing and flooding tides. Over twice as many individuals ofS. ruconius were caught during ebbing tides. Alignment of trawl direction in relation to the tidal current did not have a significant effect on the fish catch, but affected the prawn (Metapenaeus demani) catch. It is postulated that most species are not carried to and fro by tidal currents, but maintain their position in the estuary with respect to the substratum. Only prawns appeared to be carried by the currents. This study indicates that the most representative trawl results in terms of species diversity and abundance in shallow estuaries may be obtained at night and, that in estuaries with a small tidal range, tidal direction and velocity have little influence on catch. It also indicates that analyses of demersal nekton assemblages from daytime only estuarine trawl surveys must be approached with caution.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00003230
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 17
    Electronic Resource
    Electronic Resource
    The need for conservation and management of Philippine coral reefs (1988)
    Springer
    Environmental biology of fishes 23 (1988), S. 141-154 
    Details
    ISSN: 1573-5133
    Keywords: Cyanide ; Diversity ; Development ; Ecology ; Environment ; Fisheries ; Pollution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis The biological diversity and productivity of Philippine coral reefs are threatened by siltation, destructive fishing methods, coral and shell collecting and overfishing. Destructive fishing includes: the widespread, illegal use of explosives; poisons such as sodium cyanide; muro-ami and kayakas fishing; and trawling. The recent decline in catch rates threatens the livelihood of 700 000 near-shore subsistence fishermen who catch 55% of the total landings. The new government under Corazon Aquino wishes to protect the marine environment through the creation of a viable marine conservation management plan, enforcement of existing laws and through cooperation between government, non-government and international agencies to provide education and research. The Department of Agriculture, which has the authority for fisheries, has designated the International Marinelife Alliance as the lead non-government agency involved with fund raising, net-training and finding alternatives to destructive fishing methods.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00000745
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 18
    Electronic Resource
    Electronic Resource
    Rocky intertidal fish communities of California: temporal and spatial variation (1986)
    Springer
    Environmental biology of fishes 17 (1986), S. 23-40 
    Details
    ISSN: 1573-5133
    Keywords: Cottids ; Ecology ; Littoral ; Marine ; Pacific ; Sculpins ; Tidepools ; Zoogeography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis We examined data from our own and published collections of intertidal and shallow littoral fishes of the North American Pacific Coast with respect to temporal and spatial trends in species composition and dominance. We compared (1) recent and past intertidal collections made five and seven years apart, respectively, for two California localities, (2) intertidal collections from twelve localities in California, Oregon, and British Columbia, and (3) intertidal versus subtidal collections at one California locality. Temporal comparisons indicated substantially lower abundance of the cottid Oligocottus snyderi at two California localities during 1984, at one locality due to depressed abundance of young. Interannual differences in abundances suggested that other tidepool fish assemblages undergo significant changes as well. Geographical comparisons indicated general similarity in species composition, with cottids predominating in tidepools although several other families also were well represented (e.g., Stichaeidae, Scorpaenidae). Eel-shaped stichaeids and pholids occurred at high densities in exposed boulder fields. Both the tidepool and boulder field assemblages showed north-south changes in species abundances. Comparison of collections from the intertidal and subtidal zones at one California locality demonstrated that fishes of these habitats form two essentially distinct assemblages, with most species restricted to or concentrated in one or the other habitat.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00000398
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 19
    Electronic Resource
    Electronic Resource
    Growth of the Barents Sea capelin,Mallotus villosus, in relation to climate (1987)
    Springer
    Environmental biology of fishes 20 (1987), S. 293-300 
    Details
    ISSN: 1573-5133
    Keywords: Osmeridae ; Barents Sea ; Ecology ; Temperature ; Length growth ; Otoliths
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis In order to investigate a possible relationship between temperature and fish length growth in the Barents Sea capelin stock, estimates of environmental temperature in the feeding season were compared to estimates of length growth during the same season. The mean temperature of the capelin feeding area was calculated by averaging the temperatures in September for the depth interval 10–200 m in statistical rectangles. The estimates of capelin growth were obtained for the same rectangles using backcalculation of length from otoliths. Correlation coefficients for the relationship between water temperature and growth were 0.70 and 0.53 for two- and three-year-olds, respectively, when all the material was considered, and between 0.85 and 0.91 for within-year data. In addition, a close correspondence between feeding area and growth rates was found.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00005300
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 20
    Electronic Resource
    Electronic Resource
    Population dynamics ofAzospirillum brasilense and its bacteriophage in soil (1986)
    Springer
    Plant and soil 90 (1986), S. 117-128 
    Details
    ISSN: 1573-5036
    Keywords: Azospirillum ; Bacteriophage ; Chernozemic soil ; Ecology ; Latosol soil ; Podzolic soil ; Population dynamics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary This study examined the ecology and interaction ofAzospirillum brasilense and its bacteriophage in soil. Four Chernozemic soils from Canada, a Latosol and three Podzolic soils from Brazil were assayed for phage. Only the Latosol containedA. brasilense phage. None of the soils contained phage for otherA. brasilense orA. lipoferum strains tested. Recovery of phage from soil depended on the growth of indigenous or added host cells. A phage isolated from the Latosol had a hexagonal head of 100 nm and a tail of 200 nm. This phage was morphologically distinct from previously described Azospirillum phage and its host range was limited toA. brasilense strains 29145 and 29711. Survival and recovery of phage added to phage-free soil was dependent on the phage, the initial phage population, the presence of host cells and nutrients, and the soil. Phage persisted in soils at undetectable levels for at least seven weeks, but were still able to interact with multiplying host cells and exhibit a 1000-fold increase in number. Phage required a host cell population of at least 100–1000 per g of soil in order to multiply. The phage burst detected under these conditions increased as the cell to phage ratio increased. Long term incubation studies showed that the activity of phage in soil closely followed the activity of host cells and thus both were manipulated by appropriate amendments to soil.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02277391
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 21
    Electronic Resource
    Electronic Resource
    The nitrogen fixing potential ofVicia faba rhizobia (R. leguminosarum) from different agricultural locations (1986)
    Springer
    Plant and soil 92 (1986), S. 249-254 
    Details
    ISSN: 1573-5036
    Keywords: Ecology ; Nitrogen fixation ; Rhizobium leguminosarum populations ; Vicia faba
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The size and symbiotic effectiveness, withVicia faba, ofRhizobium leguminosarum populations from five locations in southern Britain has been estimated. Population numbers varied from 4.54×103 to 1.69×105. Nitrogen fixing potential differed by up to 30%. The implications of the results for improving the productivity of field beans are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02372638
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 22
    Electronic Resource
    Electronic Resource
    Technique for ecological studies of seed germination in relation to soil water potential (1986)
    Springer
    Plant and soil 95 (1986), S. 285-288 
    Details
    ISSN: 1573-5036
    Keywords: Ecology ; Germination ; Seeds ; Soil-water potential
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Seeds were germinated in soils of known matric potential (ψm) achieved by adding the requisite amount of water to air-dry soil and mixing for several days. The quantity of water was derived from calibration curves of water content against ψm by use of pressureplate extraction equipment. Soils were transferred to plastic Petri dishes in which seeds were sown. Variations of the technique permitted germination counting through the transparent dish lid, or by opening the dish and either resealing or discarding the replicate dish. Measurements of ethylene and carbon dioxide in the soil atmosphere suggest that neither gas accumulated to a level which could interfere with interpretation of results. Some species showed sensitivity of germination to water potential which was correlated with the relative wetness of their habitats.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02375080
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 23
    Electronic Resource
    Electronic Resource
    Genetics of salt tolerance in higher plants: theoretical and practical considerations (1985)
    Springer
    Plant and soil 89 (1985), S. 199-226 
    Details
    ISSN: 1573-5036
    Keywords: Ecology ; Genetics ; Physiology ; Salt tolerance ; Tomato species
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary An interdisciplinary approach to breeding for stress tolerance in plants has gained considerable recognition in the past few years. Accordingly, this article presents a synthesis of the genetic, physiological, and ecological aspects of salt tolerance in plants. An understanding of these aspects and the interrelationships between them is essential for an efficient breeding program. A significant part of the presentation concentrates on the basic problems associated with the genetics of tolerance to stresses and of quantitative characters in general, since many of the unsolved problems relevant to the genetics of salt tolerance are still general. Significant progress in the breeding of quantitative as well as qualitative traits in multicellular organisms depends on an understanding of the genetic and epigenetic dimensions of gene action. The discussion therefore includes an overview of (1) the limited existing knowledge on the genetic control of salt tolerance and (2) the physiological mechanisms and molecular targets central to the control of salt resistance as expressed by the amount and stability of yield. An additional subject emphasized here concerns the main strategies of adaptation of wild species to their natural habitats. An understanding of them is essential to (1) enable distinction between traits that can increase agricultural yield and traits that are favorable only for survival under natural conditions (such a distinction is essential, especially when wild species are used as a gene source), and (2) predict the best combinations of characters for efficient agricultural production in stressful environments.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02182243
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 24
    Electronic Resource
    Electronic Resource
    Locomotion and habitat utilization in free-rangingTarsius bancanus: A preliminary report (1986)
    Springer
    Primates 27 (1986), S. 337-355 
    Details
    ISSN: 0032-8332
    Keywords: Prosimians ; Tarsius bancanus ; Locomotion ; Ecology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Four adultTarsius bancanus were followed for a total of over 120 hrs in Sepilok Forest Reserve, Sabah, using radiotracking techniques. Seven hundred and twenty-two records of locomotor and postural behaviour were gathered.Tarsius bancanus travels a mean of 1,800 m per night, over large (4.5 to 11.25 ha) ranges. They move at a mean height of 0.89 m, utilizing primarily vertical sapling trunks of diametre 2 to 4 cm. Lateral movement is carried out largely by leaping.Tarsius were found on the ground in 5.3% of cases, but movement on the ground is very largely restricted to short investigative movements by walking. Climbing is mostly related to foraging behaviour and characteristically occurs on relatively small supports.Tarsius bancanus' locomotion is similar to, but more specialized than that ofT. spectrum, Galago alleni, andGalago senegalensis, all of which have rather similar patterns of habitat utilization. We suggest that the energetic constraints of small body size together with the need to patrol large home ranges may have lead both toTarsius bancanus extreme degree of locomotor specialization and to its exclusive animalivory.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02382075
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 25
    Electronic Resource
    Electronic Resource
    Ecology and behavior ofPresbytis thomasi in Northern Sumatra (1986)
    Springer
    Primates 27 (1986), S. 151-172 
    Details
    ISSN: 0032-8332
    Keywords: Presbytis thomasi ; Ecology ; Behavior ; Social change ; Killing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A field study of 23 bisexual troops, ranging in size from 3 to 21 members ( $$\bar x$$ =8), and two all-male groups of the Thomas's leaf monkey (Presbytis thomasi) was conducted in North Sumatra from November 1981 to April 1984. Most troops (N=19 or 82.6%) contained only one adult male. Two troops and one group were most intensively studied. The home range was 12.3–15.7 ha for the two bisexual troops, and only 1.7 ha for the one, all-male, ten-member group. Fruits composed more than 50% of their diets. Vocalizations were classified into 13 types. Births occurred at any time of the year. Among three males of a bisexual troop, serious fights were observed: two males died of wounds and the former beta male became the new alpha male. After this social change, the home range area of this troop gradually shifted eastward. But, 3.5 months after the social change, a 9-month-old infant male stayed alone in the western part of its former range. Thereafter, he became a solitary male and sometimes went into the riverine area of the Bohorok river. The occurrence of male replacement suggests instability of multi-male organization in bisexual troops. Moreover, the different mortality rate between males and females and the unequal sex ratios forced by the formation of one-male troops, maintained high tension levels among males competing on females.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02382595
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 26
    Electronic Resource
    Electronic Resource
    An ecological comparison of two sympatric primates:Saguinus fuscicollis andCallicebus moloch of Amazonian Peru (1988)
    Springer
    Primates 29 (1988), S. 465-475 
    Details
    ISSN: 0032-8332
    Keywords: Ecology ; Diet ; Sympatry ; Competition ; Polyspecific groups
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The ecologies of two sympatric primates,Saguinus fuscicollis andCallicebus moloch, were compared during a four-month field study in southeastern Peru in order to examine the mechanisms by which these primate frugivores minimize competition for food and space.Saguinus fuscicollis andCallicebus moloch were found to differ dramatically both in diet and in use of the shared habitat. Specifically, tamarins and titis showed very little overlap in their choices of food plants or animal foods and they used distinctive foraging styles, exploiting very different parts of the habitat for animal prey. Significant interspecific differences were found in the use of particular support structures and strata within the forest, and in the density of vegetation preferred. These results suggest that resource competition between saddle-backed tamarins and dusky titis is minimal, a fact that could account for the high frequency of free association between the two species and the benign nature of these interspecific contacts.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02381134
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 27
    Electronic Resource
    Electronic Resource
    Body size variation in baboons: A reconsideration of ecological determinism (1988)
    Springer
    Primates 29 (1988), S. 135-137 
    Details
    ISSN: 0032-8332
    Keywords: Papio ; Body size ; Ecology ; Climate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Popp (1983) presented an intriguing argument regarding the covariation of body size in baboons and rainfall. However, a reanalysis of the data indicates that “Principle 2” of the model is not supported.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02380856
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 28
    Electronic Resource
    Electronic Resource
    New data on the use of stone tools by chimpanzees in Guinea and Liberia (1987)
    Springer
    Primates 28 (1987), S. 473-496 
    Details
    ISSN: 0032-8332
    Keywords: Chimpanzee ; Pan troglodytes ; Tool use ; Biogeography ; Ecology ; Ethology ; Food
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Two types of use of “hammers” for cracking nuts by wild-living chimpanzees have been distinguished: (1) Relatively small stones are used by the chimpanzee community at Bossou in Guinea to crack the nuts of oil palms growing on abandoned farmland, while no nuts of wild tree species are cracked. (2) Larger hammer stones (and, at some sites, wooden clubs) are used in a more sophisticated manner to crack the nuts of wild trees, but not of oil palms, in an area ranging from south-east Sierra Leone through Liberia to the south-west of the Ivory Coast. The first author (1986) has proposed that Type I has been copied by the chimpanzees, under pressure of food shortage, from the local human population. New data now indicate that, at Bossou, while habitat deterioration has continued, the number of hammer and anvil stones per utilized oil palm tree has approximately tripled in the last six years. The quantity of food obtained from oil palm nut kernels, however, amounts to only a few percent of the total diet. For the rest these apes depend to a large extent on many other agricultural products cultivated at Bossou which they are allowed freely to consume, including even cassava (manioc) roots and sweet potatoes dug by them from the ground. Some factors determining the chosen size of hammers were analyzed. Two abnormal hammers were found whose wear suggested a tentative, human-like manner of use. No evidence has been found to indicate the use of stone tools by chimpanzees in the adjoining chimpanzee-inhabited areas around the range of the Bossou community. Type II stone tool use was found, however, in a primary forest on a mountain≈13 km west of Bossou. This is especially intriguing because the site is separated by a wide belt of drier rain forest from the belt of very humid rain forest in the south where all the other known Type II sites are located. More research on the geographical distribution of the use of stone tools by chimpanzees and on the underlying ecological factors is recommended.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02380862
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 29
    Electronic Resource
    Electronic Resource
    The importance of turbellarians in the marine meiobenthos: a review (1986)
    Springer
    Hydrobiologia 132 (1986), S. 295-303 
    Details
    ISSN: 1573-5117
    Keywords: Turbellaria ; Meiofauna ; Ecology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Recent data and opinions on meiofaunal ecology are briefly reviewed; and from scattered data, the place of turbellarians in the meiobenthic community is discussed. Turbellarian diversity, density, and biomass are higher in sandy habitats than in muddy bottoms. In sand, turbellarian diversity is of the same magnitude as that of other important meiofaunal taxa, while densities range between 7–25% of the total meiofauna. Mean individual turbellarian dry weight seems to be four times that of nematodes and in sandy habitats turbellarian biomass may be equal to or excede that of nematodes. Most turbellarian species may be considered as predators and in this respect may take the place occupied by macrofaunal species in muddy sediments. mens.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00046263
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 30
    Electronic Resource
    Electronic Resource
    Studies on ultrastructure and host range of aChlorella attacking virus (1986)
    Springer
    Protoplasma 135 (1986), S. 162-165 
    Details
    ISSN: 1615-6102
    Keywords: Alga ; Chlorella ; Ecology ; Virus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A tail-less polygonal virus with a prominent capsid of about 140–150 nm in diameter and about 14–15 nm in thickness has been isolated from a freshwater pond. It shows a marked host specificity in attacking only an endosymbioticChlorella sp. isolated fromParamecium bursaria (Ciliata). Viral replication starts in the algal cytoplasm and both autospores and old cells are lysed. The ecology of the virus in the freshwater habitat is discussed. Screening tests for further phycoviruses were not successful.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01277009
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 31
    Electronic Resource
    Electronic Resource
    Mechanisms for Speciation inGalago andTarsius (1989)
    Springer
    Human evolution 4 (1989), S. 105-116 
    Details
    ISSN: 1824-310X
    Keywords: Ecology ; locomotion ; heterochrony ; recognition concept
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Patterson's Recognition Concept of Species has profound implications for the way we analyze the process of species formation. It emphasizes absolute rather than relativistic mechanisms, and concentrates on adaptive processes within population isolates rather than competitive exclusion or competition. Environmental change is seen as a major force initiating speciation. In the case of two species ofGalago, environmental degradation and the breakup of forest blocks is likely to have been the major initiator; while changes in sea-level may have lead to the fragmentation of populations ofTarsius. In both cases, however, the relationships of body size, energetics, heterochrony and species strategies most likely provided the engine for further behavioural and morphological divergence.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02435439
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 32
    Electronic Resource
    Electronic Resource
    The physiological ecology of strandline plants (1985)
    Springer
    Plant ecology 62 (1985), S. 319-326 
    Details
    ISSN: 1573-5052
    Keywords: Atriplex ; Cakile ; Ecology ; Salsola ; Strandline
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Factors which affect the vegetation of strandlines on sandy shores were investigated with particular attention to the growth of four annual species Atriplex glabriuscula, Atriplex laciniata, Cakile maritima and Salsola kali which are widely distributed around the coasts of North-West Europe. The response of these species to increases in salinity and sand accretion are reported from laboratory experiments. Field observations were also made of photosynthesis and the availability of, and the response to, nitrogen. The results are used to discuss the adaptation of these plants to growth on strandlines in an attempt to explain their restriction to this habitat.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00044759
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 33
    facet.materialart.
    Unknown
    Recruitment dynamics in complex life cycles (1988)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 1988-09-16
    Description: Organisms living in the marine rocky intertidal zone compete for space. This, together with predation, physical disruption, and differing species tolerances to physiological stress, explains the structure of the ecological communities at some sites. At other sites the supply of larvae is limiting, and events in the offshore waters, such as wind-driven upwelling, explain the composition of intertidal communities. Whether the community ecology at a site is governed by adult-adult interactions within the site, or by limitations to the supply of larvae reaching the site, is determined by the regional pattern of circulation in the coastal waters. Models combining larval circulation with adult interactions can potentially forecast population fluctuations. These findings illustrate how processes in different ecological habitats are coupled.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Roughgarden, J -- Gaines, S -- Possingham, H -- DE-FG03-85ER60362/DE/NIDCR NIH HHS/ -- NCA2-258/CA/NCI NIH HHS/ -- New York, N.Y. -- Science. 1988 Sep 16;241(4872):1460-6.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biological Sciences, Stanford University, CA 94305, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11538249" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Ecology ; *Ecosystem ; Larva ; *Marine Biology ; *Models, Biological ; Pacific Ocean ; Plankton ; Population Dynamics ; Thoracica/*growth & development
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 34
    facet.materialart.
    Unknown
    Where was Chakrabarty's bug? (1989)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 1989-05-26
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉New York, N.Y. -- Science. 1989 May 26;244(4907):919.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11644372" target="_blank"〉PubMed〈/a〉
    Keywords: *DNA, Recombinant ; Ecology ; *Industry ; Jurisprudence ; Microbiology ; *Patents as Topic ; *Risk ; *Risk Assessment ; Supreme Court Decisions ; United States
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 35
    facet.materialart.
    Unknown
    Contributions of bird studies to biology (1989)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 1989-10-27
    Description: Birds are widely distributed, highly diversified, and exhibit behavior and social organizations equal in complexity to mammals, yet they are generally more conspicuous and approachable in natural environments. These attributes make birds excellent subjects in many areas of biological research. The topics in which studies on birds have figured prominently include the mechanisms of species formation, the regulation of the distribution and abundance of animals, the effects of the environment on behavior and physiology, the biological and evolutionary significance of variations in social organizations, the encoding of information in animal communication, the sensory basis for migration and navigation, the effects of hormones on nerve cells and behavior, the ontogeny of brain and behavior, and the structure and function of the vertebrate brain. The outstanding record of avian research suggests that birds will continue to provide important models for developing and testing new ideas in various fields of biology.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Konishi, M -- Emlen, S T -- Ricklefs, R E -- Wingfield, J C -- New York, N.Y. -- Science. 1989 Oct 27;246(4929):465-72.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Division of Biology, California Institute of Technology, Pasadena 91125.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2683069" target="_blank"〉PubMed〈/a〉
    Keywords: Adaptation, Physiological ; Animals ; Behavior, Animal/physiology ; Biological Evolution ; Biology/*methods ; Birds/*physiology ; Ecology ; Ethology/methods ; Neurobiology/methods
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 36
    facet.materialart.
    Unknown
    What makes bigger brains? (1989)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 1989-06-30
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Lewin, R -- New York, N.Y. -- Science. 1989 Jun 30;244(4912):1544.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2740901" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; *Biological Evolution ; Brain/*anatomy & histology ; Ecology ; Genetics
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 37
    facet.materialart.
    Unknown
    Genetic engineering of bacteria from managed and natural habitats (1989)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 1989-06-16
    Description: The genetic modification of bacteria from natural and managed habitats will impact on the management of agricultural and environmental settings. Potential applications include crop production and protection, degradation or sequestration of environmental pollutants, extraction of metals from ores, industrial fermentations, and productions of enzymes, diagnostics, and chemicals. Applications of this technology will ultimately include the release of beneficial agents in the environment. If safely deployed, genetically modified bacteria should be able to provide significant benefits in the management of environmental systems and in the development of new environmental control processes.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Lindow, S E -- Panopoulos, N J -- McFarland, B L -- New York, N.Y. -- Science. 1989 Jun 16;244(4910):1300-7.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Plant Pathology, University of California, Berkeley 94720.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2660261" target="_blank"〉PubMed〈/a〉
    Keywords: Agriculture ; Bacteria/*genetics ; Biodegradation, Environmental ; Ecology ; *Genetic Engineering ; Hazardous Substances/metabolism ; *Industrial Microbiology ; Recombination, Genetic ; Xenobiotics/metabolism
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 38
    facet.materialart.
    Unknown
    Taxonomic differences in the scaling of brain on body weight among mammals (1989)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 1989-06-30
    Description: Theories for the evolution of brain weight in mammals suggest that closely related species have diverged largely as a result of selection for differences in body weight, but that differences among more distantly related species have arisen due to greater net directional selection on brain weight. This pattern of changing selection causes brain weight to evolve more slowly than body weight among closely related species, such as those in the same genus, than among more distantly related species, such as those from different families or orders; a phenomenon known as the "taxon-level effect." Thus, brain weight differs more for a given difference in body weight as the species compared are more distantly related. An alternative explanation for the taxon-level effect is proposed. Distantly related species are more likely to inhabit different ecological conditions than are more closely related species. Where the taxon-level effect occurs, brain weight appears to have evolved in response to the demands of these different ecological conditions. As a consequence, brain weight differs more among distantly related species, for any given difference in body weight, than among closely related species. This effect, rather than a progressive pattern of changing selection pressures, may account for the taxon-level effect in mammals.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Pagel, M D -- Harvey, P H -- New York, N.Y. -- Science. 1989 Jun 30;244(4912):1589-93.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Zoology, University of Oxford, United Kingdom.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2740904" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Artiodactyla/anatomy & histology ; *Biological Evolution ; *Body Weight ; Brain/*anatomy & histology ; Carnivora/anatomy & histology ; Chiroptera/anatomy & histology ; Ecology ; Mammals/*anatomy & histology/classification ; Models, Biological ; Organ Size ; Primates/anatomy & histology ; Regression Analysis ; Rodentia/anatomy & histology ; Selection, Genetic ; Species Specificity ; Statistics as Topic
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 39
    facet.materialart.
    Unknown
    Biological defense defended (1988)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 1988-05-20
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Norman, Colin -- New York, N.Y. -- Science. 1988 May 20;240(4855):981.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11644306" target="_blank"〉PubMed〈/a〉
    Keywords: *Biological Warfare ; Containment of Biohazards ; DNA, Recombinant ; Ecology ; Federal Government ; Government ; Government Regulation ; Hazardous Substances ; International Cooperation ; Internationality ; Politics ; Social Control, Formal ; United States
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 40
    facet.materialart.
    Unknown
    Predator-induced trophic shift of a free-living ciliate: parasitism of mosquito larvae by their prey (1988)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 1988-05-27
    Description: Larvae of the treehole mosquito, Aedes sierrensis, release a waterborne factor that induces morphogenesis of one of their prey, the tetrahymenid ciliate Lambornella clarki. Induced free-living trophonts of L. clarki undergo a synchronous response in which cells divide and transform into parasitic cells (theronts) that encyst on larval predators. Parasitic ciliates penetrate the cuticle, enter the hemocoel, and ultimately kill their predator-host. In nature, this trophic shift can lead to predator extinction and dramatic changes in microbial populations. Facultative parasitism by this polymorphic ciliate may have evolved as an antipredator strategy. The experimentally inducible parasitic response of L. clarki provides a novel model for studying cellular morphogenesis of ciliated protozoa.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Washburn, J O -- Gross, M E -- Mercer, D R -- Anderson, J R -- AI20245/AI/NIAID NIH HHS/ -- New York, N.Y. -- Science. 1988 May 27;240(4856):1193-5.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Entomological Sciences, University of California, Berkely 94720.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/3131877" target="_blank"〉PubMed〈/a〉
    Keywords: Aedes/*parasitology/physiology ; Animals ; Ciliophora/growth & development/*physiology ; Ecology ; Larva ; Predatory Behavior
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 41
    facet.materialart.
    Unknown
    Life history patterns emerge in primate study (1988)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 1988-12-23
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Lewin, R -- New York, N.Y. -- Science. 1988 Dec 23;242(4886):1636-7.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/3201254" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Body Weight ; Ecology ; *Environment ; Population Growth ; *Primates ; Selection, Genetic
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 42
    facet.materialart.
    Unknown
    Habitat selection in a clonal plant (1985)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 1985-05-03
    Description: Rhizomatous growth may permit the nonrandom placement of ramets into different environments, but whether clonal plants are able to use this means to exercise adaptive habitat choice is not known. Western ragweed (Ambrosia psilostachya) plants are shown to preferentially colonize nonsaline soil over saline soil patches, and clones with the strongest preference for nonsaline soil are those least able to grow when restricted to saline conditions. In clonal plant species, nonrandom associations of genotypes with specific environments may thus reflect habitat selection by plants as well as selective mortality imposed by different habitat patches.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Salzman, A G -- GN 07197/PHS HHS/ -- New York, N.Y. -- Science. 1985 May 3;228(4699):603-4.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/3983647" target="_blank"〉PubMed〈/a〉
    Keywords: Ecology ; *Plant Physiological Phenomena ; Sodium Chloride ; Soil
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 43
    facet.materialart.
    Unknown
    Judge blocks biological warfare laboratory (1985)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 1985-06-21
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Smith, R Jeffrey -- New York, N.Y. -- Science. 1985 Jun 21;228(4706):1411.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11643779" target="_blank"〉PubMed〈/a〉
    Keywords: *Biological Warfare ; *DNA, Recombinant ; Ecology ; Federal Government ; Government ; *Government Regulation ; Humans ; Judicial Role ; *Jurisprudence ; Microbiology ; Military Personnel ; Politics ; *Public Policy ; *Social Control, Formal ; Utah
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 44
    facet.materialart.
    Unknown
    Court hears suit on biowarfare laboratory (1985)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 1985-05-17
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Smith, R Jeffrey -- New York, N.Y. -- Science. 1985 May 17;228(4701):827-8.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11643758" target="_blank"〉PubMed〈/a〉
    Keywords: *Biological Warfare ; Containment of Biohazards ; *DNA, Recombinant ; Ecology ; Federal Government ; Government ; Government Regulation ; Hazardous Substances ; Jurisprudence ; *Public Policy ; Social Control, Formal ; United States
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 45
    facet.materialart.
    Unknown
    Army agrees to new study of biowarfare laboratory (1985)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 1985-02-08
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Smith, R Jeffrey -- New York, N.Y. -- Science. 1985 Feb 8;227(4687):614.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11643708" target="_blank"〉PubMed〈/a〉
    Keywords: *Biological Warfare ; *DNA, Recombinant ; Ecology ; Federal Government ; Government ; Government Regulation ; Humans ; Jurisprudence ; Microbiology ; Military Personnel ; Politics ; *Public Policy ; Research Personnel ; Social Control, Formal ; Utah
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 46
    facet.materialart.
    Unknown
    Administration divided over OECD biotech plan (1985)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 1985-08-30
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Sun, Marjorie -- New York, N.Y. -- Science. 1985 Aug 30;229(4716):842-3.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11643793" target="_blank"〉PubMed〈/a〉
    Keywords: Biomedical Research ; Containment of Biohazards ; *DNA, Recombinant ; Ecology ; Europe ; Federal Government ; Government ; *Government Regulation ; Hazardous Substances ; *Industry ; *International Cooperation ; *Internationality ; Japan ; *Public Policy ; Research ; *Social Control, Formal ; United States ; and Development (OECD)--which includes the United States, most of its European ; allies, and Japan--have been discussing how to set up international guidelines to ; regulate the emerging biotechnology industry. A May 1985 first draft of the ; guidelines spawned many objections, and now a revised draft, called "Safety and ; Regulations in Biotechnology," has encountered mixed responses from U.S. federal ; agencies. The Environmental Protection Agency generally supports the document, ; but the State Department, Food and Drug Administration, and Department of ; Agriculture have significant objections to its tone and substance, particularly ; in regard to the specificity of safety controls over the commercial development ; of recombinant DNA organisms used in large-scale production and for agricultural ; purposes.
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 47
    facet.materialart.
    Unknown
    Biotech policy draws flood of comments (1985)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 1985-06-14
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Sun, Marjorie -- New York, N.Y. -- Science. 1985 Jun 14;228(4705):1296.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11643759" target="_blank"〉PubMed〈/a〉
    Keywords: Advisory Committees ; *DNA, Recombinant ; Ecology ; Federal Government ; Government ; *Government Regulation ; Industry ; Public Policy ; Risk ; Risk Assessment ; *Social Control, Formal ; *United States Environmental Protection Agency ; has elicited dozens of letters from researchers, industry, environmental groups, ; and others in response to the Environmental Protection Agency's (EPA) proposed ; role. Many commentators took issue with the EPA's intention to subject the ; products of genetic engineering to more rigorous scrutiny than conventionally ; manufactured products, a policy that the agency defends on the premise that ; genetically manipulated substances may pose more risks. Several respondents also ; claimed that products produced by genetic techniques not involving recombinant ; DNA are not "new," and therefore not subject to EPA's authority. Questions were ; asked as well about the need for the Biotechnology Science Board that the ; government plans to establish to oversee review committees in federal agencies ; involved with biotechnology research.
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 48
    facet.materialart.
    Unknown
    Regulatory structure for biotechnology proposed (1985)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 1985-01-18
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Sun, Marjorie -- New York, N.Y. -- Science. 1985 Jan 18;227(4684):274.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11643694" target="_blank"〉PubMed〈/a〉
    Keywords: Advisory Committees ; Biomedical Research ; *DNA, Recombinant ; Ecology ; *Federal Government ; *Government ; *Government Regulation ; *Industry ; National Institutes of Health (U.S.) ; Public Policy ; Research ; *Social Control, Formal ; United States Dept. of Health and Human Services ; United States Environmental Protection Agency ; United States Food and Drug Administration ; the White House Office of Science and Technology Policy in the 31 December 1984 ; Federal Register. The report describes how the Environmental Protection Agency, ; the Food and Drug Administration, and the Department of Agriculture intend to use ; current laws and guidelines to regulate the new field of genetic engineering. It ; also proposes that these agencies and the National Science Foundation set up ; review groups similar to the Recombinant DNA Advisory Committee of the National ; Institutes of Health. The committees would report to an interagency board that ; would monitor scientific and regulatory consistency and address broad policy ; issues.
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 49
    facet.materialart.
    Unknown
    Monsanto may bypass NIH in microbe test (1985)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 1985-01-11
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Sun, Marjorie -- New York, N.Y. -- Science. 1985 Jan 11;227(4683):153.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11643692" target="_blank"〉PubMed〈/a〉
    Keywords: *DNA, Recombinant ; Ecology ; Federal Government ; Government ; *Government Regulation ; *Industry ; National Institutes of Health (U.S.) ; Public Policy ; *Social Control, Formal ; *United States Environmental Protection Agency ; for clearance to field test a genetically engineered microbial pesticide, ; bypassing the traditional approval process of the National Institutes of Health. ; Although only federally funded institutions are required to obtain NIH approval ; for genetic engineering tests, Monsanto is the first company to bypass the NIH ; regulatory process, which has become mired in a lawsuit brought by Jeremy Rifkin.
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 50
    facet.materialart.
    Unknown
    USDA biotechnology review criticized and defended (1986)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 1986-04-18
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Sun, Marjorie -- New York, N.Y. -- Science. 1986 Apr 18;232(4748):316.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11643917" target="_blank"〉PubMed〈/a〉
    Keywords: *DNA, Recombinant ; Ecology ; *Federal Government ; *Government ; *Government Regulation ; Industry ; Microbiology ; Politics ; Public Policy ; *Social Control, Formal ; United States
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 51
    facet.materialart.
    Unknown
    Vertical distribution of an estuarine snail altered by a parasite (1987)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 1987-03-20
    Description: Estuarine snails Ilyanassa obsoleta bearing larvae of the trematode Gynaecotyla adunca behave singularly in comparison with conspecifics lacking this parasite. Following high tides, and especially at night, infected snails were found stranded high on beaches and sandbars. Semiterrestrial crustaceans living well up on the shore serve as the next host, and the modified (induced) snail behavior is apparently a parasite adaptation facilitating cercarial transmission to these crustaceans. The altered behavior is unusual because of its apparent enhancement of host-to-host transmission by cercariae rather than predation, the process commonly recognized as being enhanced by parasitic modification of host behavior.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Curtis, L A -- New York, N.Y. -- Science. 1987 Mar 20;235(4795):1509-11.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/3823901" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Behavior, Animal/physiology ; Delaware ; Ecology ; Snails/*parasitology ; Trematoda/*physiology
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 52
    facet.materialart.
    Unknown
    Ecology of modern humans (1987)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 1987-09-11
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Lewin, R -- New York, N.Y. -- Science. 1987 Sep 11;237(4820):1295.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/3114878" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Anthropology ; Ecology ; Geography ; *Haplorhini ; Humans
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 53
    facet.materialart.
    Unknown
    How safe are engineered organisms? (1985)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 1985-07-05
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Kolata, G -- New York, N.Y. -- Science. 1985 Jul 5;229(4708):34-5.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/3859922" target="_blank"〉PubMed〈/a〉
    Keywords: Agriculture ; *Containment of Biohazards ; Ecology ; Genetic Engineering/*standards ; *Government Regulation ; Molecular Biology ; *Risk Assessment ; Scientific Issues" organized by the American Society for Microbiology, ecologists ; voiced their concern to molecular biologists about the safety of releasing ; genetically-engineered organisms into the environment without proper regulation. ; Under discussion were four proposed experiments, three in agriculture and one ; involving the production of a genetically-engineered smallpox vaccine at the ; National Institute of Allergy and Infectious Diseases. The agricultural ; experiments involve organisms developed at the University of California, ; Berkeley, to make potato plants frost-resistant, a Monsanto microbial pesticide, ; and herbicide-tolerant plants developed by Calgene.
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 54
    facet.materialart.
    Unknown
    Fuqua biotech bill sets stage for industry debate (1986)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 1986-03-28
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Crawford, Mark -- New York, N.Y. -- Science. 1986 Mar 28;231(4745):1501.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11643911" target="_blank"〉PubMed〈/a〉
    Keywords: *Advisory Committees ; *DNA, Recombinant ; Ecology ; *Federal Government ; *Government ; *Government Regulation ; Industry ; Microbiology ; Politics ; *Public Policy ; *Social Control, Formal ; United States ; United States Environmental Protection Agency
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 55
    facet.materialart.
    Unknown
    The Critical Role of Computational Fluid Dynamics in Rotary-Wing Aerodynamics (1986)
    In:  Other Sources
    Details
    Publication Date: 2011-08-23
    Description: Helicopter rotor aerodynamics is basically the study of unsteady aerodynamic flows in a rotating and translating coordinate system. Current trends in this field are briefly reviewed by examining recent advances in lifting-surface theory, wake modeling, panel methods, and finite-difference models' Examples are used to illustrate selected current methods and some indications of promising future directions are highlighted.
    Keywords: Aerodynamics
    Type: Vertica (ISSN 0360-5450); Volume 11; Nos. 1, 2; 43-63
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 56
    facet.materialart.
    Unknown
    Helicopter Model Rotor-Blade Vortex Interaction Impulsive Noise: Scalability and Parametric Variations (1987)
    In:  Other Sources
    Details
    Publication Date: 2011-08-23
    Description: Acoustic data taken in the anechoic Deutsch-Niederlaendischer Windkanal (DNW) have documented the blade-vortex interaction (BVI) impulsive noise radiated from a 1/7-scale model main rotor of the AH-1 series helicopter. Averaged model-scale data were compared with averaged full-scale, in-flight acoustic data under similar non-dimensional test conditions using an improved data analysis technique. At low advance ratios (mu = 0.164 - 0.194), the BVI impulsive noise data scale remarkably well in level, waveform, and directivity patterns. At moderate advance ratios (mu = 0.224 - 0.270), the scaling deteriorates, suggesting that the model-scale rotor is not adequately simulating the full-scale BVI noise. Presently, no proved explanation of this discrepancy exists. Measured BVI noise radiation is highly sensitive to all of the four governing nondimensional parameters--hover tip Mach number, advance ratio, local inflow ratio, and thrust coefficient.
    Keywords: Aerodynamics
    Type: Journal of the American Helicopter Society; Volume 32; No. 1; 3-12
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 57
    facet.materialart.
    Unknown
    Riblet Research (1985)
    In:  CASI
    Details
    Publication Date: 2018-06-09
    Description: Research at Langley on skin friction drag was described in Tech Briefs. 3M engineers suggested to Langley that grooves molded into a lightweight plastic film with adhesive backing and pressed on an airplane would be simpler than cutting grooves directly onto the surface. Boeing became involved and tested the "riblet" on an olympic rowing shell; the US won a silver medal. Based on the riblet-like projections on shark's skins, the technology may provide a 5 percent fuel saving for airplanes. Product is no longer commercially available.
    Keywords: Aerodynamics
    Type: Spinoff 1985; 66-67
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 58
    facet.materialart.
    Unknown
    Investigation of a 1/4-Scale Model of the Republic F-105 Airplane in the Langley 19-Foot Pressure Tunnel: Longitudinal Stability and Control of the Model Equipped with a Supersonic-Type Elliptical Wing-Root Inlet (1954)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: No abstract available
    Keywords: Aerodynamics
    Type: NACA-RM-SL54F28
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 59
    facet.materialart.
    Unknown
    A Correlation by Means of the Transonic Similarity Rules of the Experimentally Determined Characteristics of 22 Rectangular Wings of Symmetrical Profile (1952)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: The transonic similarity rules have been applied to the correlation of experimental data for a series of 22 rectangular wings having symmetrical NACA 63A-series sections, aspect ratios from 1/2 to 6, and thicknesses from 2 to 10 percent. The data were obtained by use of the transonic bump technique over a Mach number range from 0.40 to 1.10, corresponding to a Reynolds number range from 1.25 to 2.05 million. The results show that it is possible to correlate experimental data throughout the subsonic, transonic, and moderate supersonic regimes by using the transonic similarity parameters in forms which are consistent with the Prandtl-Glauert rule of linearized theory. The multiple families of basic data curves for the various aspect ratios and thickness ratios have been summarized in single presentations involving only one geometric variable - the product of the aspect ratio and the l/3 power of the thickness ratio.
    Keywords: Aerodynamics
    Type: NACA-RM-A51L17b
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 60
    facet.materialart.
    Unknown
    Performance Characteristics of Plane-Wall Two-Dimensional Diffusers (1953)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Experiments have been made at Stanford University to determine the performance characteristics of plane-wall, two-dimensional diffusers which were so proportioned as to insure reasonable approximation of two-dimensional flow. All of the diffusers had identical entrance cross sections and discharged directly into a large plenum chamber; the test program included wide variations of divergence angle and length. During all tests a dynamic pressure of 60 pounds per square foOt was maintained at the diffuser entrance and the boundary layer there was thin and fully turbulent. The most interesting flow characteristics observed were the occasional appearance of steady, unseparated, asymmetric flow - which was correlated with the boundary-layer coalescence - and the rapid deterioration of flow steadiness - which occurred as soon as the divergence angle for maximum static pressure recovery was exceeded. Pressure efficiency was found to be controlled almost exclusively by divergence angle, whereas static pressure recovery was markedly influenced by area ratio (or length) as well as divergence angle. Volumetric efficiency. diminished as area ratio increased, and at a greater rate with small lengths than with large ones. Large values of the static-pressure-recovery coefficient were attained only with long diffusers of large area ratio; under these conditions pressure efficiency was high and. volumetric efficiency low. Auxiliary tests with asymmetric diffusers demonstrated that longitudinal pressure gradient, rather than wall divergence angle, controlled flow separation. Others showed that the addition of even a short exit duct of uniform section augmented pressure recovery. Finally, it was found that the installation of a thin, central, longitudinal partition suppressed flow separation in short diffusers and thereby improved pressure recovery
    Keywords: Aerodynamics
    Type: NACA-TN-2888
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 61
    facet.materialart.
    Unknown
    Preliminary Report on Laminar-Flow Airfoils and New Methods Adopted for Airfoil and Boundary-Layer Investigations (1939)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Recent developments in airfoil-testing methods and fundamental air-flow investigations, as applied to airfoils, are discussed. Preliminary test results, obtained under conditions relatively free from stream turbulence and other disturbances, are presented. Suitable airfoils and airfoil-design principles were developed to take advantage of the unusually extensive laminar boundary layers that may be maintained under the improved testing conditions. The results are of interest mainly in range of below 6,000,000.
    Keywords: Aerodynamics
    Type: NACA-WR-L-345
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 62
    facet.materialart.
    Unknown
    The Compressibility Burble (1935)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Simultaneous air-flow photographs and pressure-distribution measurements have been made of the NACA 4412 airfoil at high speeds in order to determine the physical nature of the compressibility burble. The flow photographs were obtained by the Schlieren method and the pressures were simultaneously measured for 54 stations on the 5-inch-chord wing by means of a multiple-tube photographic manometer. Pressure-measurement results and typical Schlieren photographs are presented. The general nature of the phenomenon called the "compressibility burble" is shown by these experiments. The source of the increased drag is the compression shock that occurs, the excess drag being due to the conversion of a considerable amount of the air-stream kinetic energy into heat at the compression shock.
    Keywords: Aerodynamics
    Type: NACA-TN-543
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 63
    facet.materialart.
    Unknown
    Theoretical Performance Characteristics of Sharp Lip Inlets at Subsonic Speeds (1953)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: A method is presented for the estimation of the subsonic-flight-speed characteristics of sharp-lip inlets applicable to supersonic aircraft. The analysis, based on a simple momentum balance consideration, permits the computation of inlet pressure recovery - mass-flow relations and additive-drag coefficients for forward velocities from zero to the speed of sound. The penalties for operation of a sharp-lip inlet at velocity ratios other than 1.0 may be severe; at lower velocity ratios an additive drag is incurred that is not cancelled by lip suction, while at higher velocity ratios, unavoidable losses in inlet total pressure will result. In particular, at the take-off condition, the total pressure and the mass flow for a choked inlet are only 79 percent of the values ideally attainable with a rounded lip. Experimental data obtained at zero speed with a sharp-lip supersonic inlet model were in substantial agreement with the theoretical results.
    Keywords: Aerodynamics
    Type: NACA-TN-3004
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 64
    facet.materialart.
    Unknown
    On the Development of Turbulent Wakes from Vortex Streets (1953)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Wake development behind circular cylinders at Reynolds numbers from 40 to 10,000 was investigated in a low-speed wind tunnel. Standard hotwire techniques were used to study the velocity fluctuations. The Reynolds number range of periodic vortex shedding is divided into two distinct subranges. At R = 40 to 150, called the stable range, regular vortex streets are formed and no turbulent motion is developed. The range R = 150 to 300 is a transition range to a regime called the irregular range, in which turbulent velocity fluctuations accompany the periodic formation of vortices. The turbulence is initiated by laminar-turbulent transition in the free layers which spring from the separation points on the cylinder. This transition first occurs in the range R = 150 to 300. Spectrum and statistical measurements were made to study the velocity fluctuations. In the stable range the vortices decay by viscous diffusion. In the irregular range the diffusion is turbulent and the wake becomes fully turbulent in 40 to 50 diameters downstream. It was found that in the stable range the vortex street has a periodic spanwise structure. The dependence of shedding frequency on velocity was successfully used to measure flow velocity. Measurements in the wake of a ring showed that an annular vortex street is developed.
    Keywords: Aerodynamics
    Type: NACA-TN-2913
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 65
    facet.materialart.
    Unknown
    Preliminary Investigation of a New Type of Supersonic Inlet (1951)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: A supersonic inlet with supersonic deceleration of the flow entirely outside of the inlet is considered. A particular arrangement with fixed geometry having a central body with a circular annular intake is analyzed, and it is shown theoretically that this arrangement gives high pressure recovery for a large range of Mach number and mass flow and therefore is practical for use on supersonic airplanes and missiles. For some Mach numbers the drag coefficient for this type of inlet is larger than the drag coefficient for the type of inlet with supersonic compression entirely inside, but the pressure recovery is larger for all flight conditions. The differences in drag can be eliminated for the design Mach number. Experimental results confirm the results of the theoretical analysis and show that pressure recoveries of 95 percent for Mach numbers of 1.33 and 1.52, 92 percent for a Mach number of 1.72, and 86 percent for a Mach number of 2.10 are possible, with the configurations considered. If the mass flow decreases, the total drag coefficient increases gradually and the pressure recovery does not change appreciably. The results of this work were first presented in a classified document issued in 1946.
    Keywords: Aerodynamics
    Type: NACA-TN-2286
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 66
    facet.materialart.
    Unknown
    An Analysis of the Applicability of the Hypersonic Similarity Law to the Study of Flow About Bodies of Revolution at Zero Angle of Attack (1950)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: The hypersonic similarity law as derived by Tsien has been investigated by comparing the pressure distributions along bodies of revolution at zero angle of attack. In making these comparisons, particular attention was given to determining the limits of Mach number and fineness ratio for which the similarity law applies. For the purpose of this investigation, pressure distributions determined by the method of characteristics for ogive cylinders for values of Mach numbers and fineness ratios varying from 1.5 to 12 were compared. Pressures on various cones and on cone cylinders were also compared in this study. The pressure distributions presented demonstrate that the hypersonic similarity law is applicable over a wider range of values of Mach numbers and fineness ratios than might be expected from the assumptions made in the derivation. This is significant since within the range of applicability of the law a single pressure distribution exists for all similarly shaped bodies for which the ratio of free-stream Mach number to fineness ratio is constant. Charts are presented for rapid determination of pressure distributions over ogive cylinders for any combination of Mach number and fineness ratio within defined limits.
    Keywords: Aerodynamics
    Type: NACA-TN-2250
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 67
    facet.materialart.
    Unknown
    An Approximate Method of Calculating Pressures in the Tip Region of a Rectangular Wing of Circular-Arc Section at Supersonic Speeds (1950)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: No abstract available
    Keywords: Aerodynamics
    Type: NACA-TN-2211
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 68
    facet.materialart.
    Unknown
    Systematic Two-Dimensional Cascade Tests of NACA 65-Series Compressor Blades at Low Speeds (1951)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: The performance of NACA 65-series compressor blade section in cascade has been investigated systematically in a low-speed cascade tunnel. Porous test-section side walls and for high-pressure-rise conditions, porous flexible end walls were employed to establish conditions closely simulating two-dimensional flow. Blade sections of design lift coefficients from 0 to 2.7 were tested over the usable angle-of-attack range for various combinations of inlet-flow angle. A sufficient number of combinations were tested to permit interpolation and extrapolation of the data to all conditions within the usual range of application. The results of this investigation indicate a continuous variation of blade-section performance as the major cascade parameters, blade camber, inlet angle, and solidity were varied over the test range. Summary curves of the results have been prepared to enable compressor designers to select the proper blade camber and angle of attack when the compressor velocity diagram and desired solidity have been determined.
    Keywords: Aerodynamics
    Type: NACA-TR-1368 , NACA-RM-L51G31
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 69
    facet.materialart.
    Unknown
    Experimental Study of Isothermal Wake-Flow Characteristics of Various Flame-Holder Shapes (1952)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: An investigation of the isothermal wake-flow characteristics of several flame-holder shapes was carried out in a 4- by 4-inch flow chamber. The effects of flame-holder-shape changes on the characteristics of the Karman vortices and thus on the recirculation zones to which experimenters have related the combustion process were obtained for several flame holders. The results may furnish a basis of correlation, of combustion efficiency and stability for similarly shaped flame holders in combustion studies. Values of the spacing ratio-(ratio of lateral spacing to longitudinal spacing of vortices] obtained for the various shapes approximated the theoretical value of 0.36 given by the Karman stability analysis. Variations in vortex strength of more than 200 percent and in frequency of more than 60 percent were accomplished by varying flame-holder shape. A maximum increase in the recirculation parameter of 56 percent over that for a conventional V-gutter was also obtained. Varying flameholder shape and size enables the designer to select many schedules of variations in vortex strength and frequency- not obtainable by changing size only and may make it possible to approach theoretical maximum vortex strength for any given frequency.
    Keywords: Aerodynamics
    Type: NACA-RM-E51K07 , E-2403
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 70
    facet.materialart.
    Unknown
    Wind-tunnel investigation of the descent characteristics of bodies of revolution simulating anti-personnel bombs (1951)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: An investigation has been conducted in the Langley 20-foot free spinning tunnel to study the relative behavior in descent of a number of homogeneous balsa bodies of revolution simulating anti-personnel bombs with a small cylindrical exploding device suspended approximately 10 feet below the bomb. The bodies of revolution included hemispherical, near-hemispherical, and near-paraboloid shapes. The ordinates of one near-paraboloid shape were specified by the Office of the Chief of Ordnance, U. S. Army. The behavior of the various bodies without the cylinder was also investigated. The results of the investigation indicated that several of the bodies descended vertically with their longitudinal axis, suspension line, and small cylinder in a vertical attitude,. However, the body, the ordinates of which had been specified by the Office of the Chief of Ordnance, U. S. Army, oscillated considerably from a vertical attitude while descending and therefore appeared unsuitable for its intended use. The behavior of this body became satisfactory when its center of gravity was moved well forward from its original position. In general, the results indicated that the descent characteristics of the bodies of revolution become more favorable as their shapes approached that of a hemisphere.
    Keywords: Aerodynamics
    Type: NACA-RM-SL51L13
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 71
    facet.materialart.
    Unknown
    Aerodynamic Loads Induced by a Rotor on a Body of Revolution (1986)
    In:  Other Sources
    Details
    Publication Date: 2019-07-13
    Description: A wind-tunnel investigation was conducted in which aerodynamic loads were measured on a small-scale helicopter rotor and a body of revolution located close to it as an idealized model of a fuselage. The objective was to study the aerodynamic interactions as a function of forward speed, rotor thrust, and rotor/body position. Results show that body loads, normalized by rotor thrust, are functions of the ratio between free-stream velocity and the hover-induced velocity predicted by momentum theory.
    Keywords: Aerodynamics
    Type: May 01, 1983; Saint Louis, MO; United States|Journal of the American Helicopters; 29-36
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 72
    facet.materialart.
    Unknown
    Free-Tip Rotor Wind Tunnel Test Results (1985)
    In:  Other Sources
    Details
    Publication Date: 2019-07-13
    Description: A new rotor blade tip design called the free-tip has been proposed as a means to improve forward flight performance characteristics and reduce oscillatory loads. The free-tip design incorporates a tip that is free to pitch independently of the rest of the blade. Pitching about an axis forward of the quarter-chord, the tip weathervanes into its local wind, thus reducing angle of attack perturbations and the resulting oscillatory lift loadings. A nearly constant nose-up pitching moment is applied mechanically to the tip so that the tip, to maintain pitching equilibrium, produces nearly steady positive lift around the azimuth. A wind-tunnel test of a small-scale, 5.1 m diameter model rotor was conducted to obtain comparative forward flight performance and oscillatory loads data with the tips free and fixed. The free-up was shown to reduce power in trimmed flight over a wide range of advance ratio and thrust; at an advance ratio of 0.3 and C(sub L)/sigma of 0.08 the reduction is 12%. Oscillatory flapwise bending-moments and oscillatory pitch link loads are also reduced, but the oscillatory in-plane bending moments increase.
    Keywords: Aerodynamics
    Type: May 01, 1985; Fort Worth, TX; United States
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 73
    facet.materialart.
    Unknown
    Effects of Blade to Blade Dissimilarities on Rotor Body Lead Lag Dynamics (1985)
    In:  Other Sources
    Details
    Publication Date: 2019-07-13
    Description: Small blade-to-blade property differences are investigated to determine how they affect the behavior of a simple rotor-body system. An analytical approach is used which emphasizes the significance of these effects from the experimental point of view. It is found that the primary effect of blade-to-blade dissimilarities is the appearance of additional peaks in the frequency spectrum which are separated from the conventional response peaks by multiples of the rotor speed. These additional responses are potential experimental problems because when they occur near a mode of interest they act as contaminant frequencies which can make damping measurements difficult. Increased rotor-body coupling and a rotor shaft degree of freedom act to improve the situation by altering the frequency separation of the modes.
    Keywords: Aerodynamics
    Type: European Rotorcraft; Sep 01, 1985; London; United Kingdom
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 74
    facet.materialart.
    Unknown
    Effect of Helicopter Blade Dynamics on Blade Aerodynamic and Structural Loads (1987)
    In:  Other Sources
    Details
    Publication Date: 2019-07-13
    Description: The effect of rotor blade dynamics on aerodynamic and structural loads is examined for a conventional, main- rotor helicopter using both a comprehensive rotorcraft analysis (CAMRAD) and night test data. The impact of blade dynamics on blade section lift-coefficient time histories is studied by comparing predictions from both a rigid blade analysis and an elastic blade analysis with helicopter flight test data. The elastic blade analysis better predicts high-frequency behavior of section lift. In addition, components of the blade angle of attack, such as elastic blade twist, blade nap rate, blade slope velocity, and inflow, are examined as a function of blade mode. Elastic blade motion affects the blade angle of attack by a few tenths of a degree, and up to the sixth rotor harmonic. A similar study of the influence of blade dynamics on bending and torsion moments was also conducted. The modal analysis of the predicted blade structural loads suggested that five elastic bending deg of freedom (four flap and one lag) and three elastic torsion deg of freedom contributed to calculations of the blade structural loads. However, when structural bending load predictions from several elastic blade analyses were compared with flight test data, an elastic blade model consisting of only three elastic bending modes (first and second flap, and first lag), and two elastic torsion modes was found to be sufficient for maximum correlation.
    Keywords: Aerodynamics
    Type: Dynamics Specialists; Apr 10, 1987 - Apr 12, 1987; Monterey, CA; United States
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 75
    facet.materialart.
    Unknown
    Wind-Tunnel Investigation of an N.A.C.A. 23012 Airfoil with a Slotted Flap and Three Types of Auxiliary Flap (1938)
    In:  CASI
    Details
    Publication Date: 2019-08-26
    Description: An investigation was made in the N.A.C.A. 7- by 10- foot wind tunnel to determine the aerodynamic section characteristics of an N. A. C. A. 23012 airfoil with a single main slotted flap equipped successively with auxiliary flaps of the plain, split, and slotted types. A test installation mas used in which an airfoil of 7-foot span was mounted vertically between the upper and the lower sides of the closed test section so that two-dimensional flow was approximated. On the basis of maximum lift coefficient, low drag at moderate and high lift coefficients, and high drag at high lift coefficients, the optimum combination of the arrangements was found to be the double slotted flap . All the auxiliary flaps tested, however, increased the magnitudes of the pitching moments over those of the main slotted flap alone.
    Keywords: Aerodynamics
    Type: NACA-SR-97
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 76
    facet.materialart.
    Unknown
    The Base Pressure at Supersonic Speeds on Two-Dimensional Airfoils and Bodies of Revolution (With and Without Fins) Having Turbulent Boundary Layers (1953)
    In:  CASI
    Details
    Publication Date: 2019-08-17
    Description: An analysis has been made of available experimental data to show the effects of most variables that are predominant in determining base pressure at supersonic speeds. Two dimensional bases and bases of bodies of revolution, restricted to turbulent boundary layers, are covered.
    Keywords: Aerodynamics
    Type: NACA-RM-L53C02
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 77
    facet.materialart.
    Unknown
    The Effect of Nose Shape on the Drag of Bodies of Revolution at Zero Angle of Attack (1951)
    In:  CASI
    Details
    Publication Date: 2019-08-16
    Description: The subject of this paper is the drag of the nose section of bodies of revolution at zero angle of attack. The magnitude of the nose drag in relation to the total drag is very distinctly a function of the body design and the Mach number. It can range from a very small fraction of the total drag of the order of 10 percent to a very large fraction as high as 80 percent. The natural objective of nose design is to minimize the drag, but this objective is not always the primary one. Sometimes other factors overshadow the desire for minimum drag. The most conspicuous example of this is the proposal of guidance engineers that large-diameter spheres and other very blunt shapes be used at the nose tip. This paper will attempt to discuss both phases of the problem, noses for minimum drag and noses with very blunt tips. The state of the theory will also be reviewed and recent theoretical developments described, since the theory still remains a very valuable tool for assaying the effects of compromises in design and departure from shapes for which experimental data are available.
    Keywords: Aerodynamics
    Type: Aerodynamic Characteristics of Bodies at Supersonic Speeds: A Collection of Three Papers; 1-12; NACA-RM-A51J25|NACA Conference on Aerodynamic Design Problems of Supersonic Guided Missiles; Oct 02, 1951 - Oct 03, 1951; Moffett Field, CA; United States
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 78
    facet.materialart.
    Unknown
    Elastic Buckling under Combined Stresses of Flat Plates with Integral Waffle-Like Stiffening (1953)
    In:  CASI
    Details
    Publication Date: 2019-07-11
    Description: Theory and experiment were compared and found in good agreement for the elastic Buckling under combined stresses of long flat plates with integral waffle-like stiffening in a variety of configurations. For such flat plates, 45deg waffle stiffening was found to be the most effective of the configurations for the proportions considered over the widest range of combinations of compression and shear.
    Keywords: Aerodynamics
    Type: NACA-RM-L53J27
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 79
    facet.materialart.
    Unknown
    Rocket-Model Measurements of Zero-Lift Damping in Roll of the Bell MX-776 Missile at Mach Numbers from 0.6 to 1.56 (1953)
    In:  CASI
    Details
    Publication Date: 2019-07-11
    Description: The zero-lift damping in roll of the Bell MX-776 missile has been measured by a sting-mounted rocket-model technique at Mach numbers from 0.6 to 1.56. The damping-in-roll data, in general, show no unusual variation with Mach number. Aileron rolling-moment effectiveness derived from these data and previously obtained rolling-effectiveness data appear reasonable,
    Keywords: Aerodynamics
    Type: NACA-RM-SL54A13
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 80
    facet.materialart.
    Unknown
    An Investigation of the Aerodynamic Characteristics in Pitch of an XB-52 Airplane Model in a High-Speed Wind Tunnel (1951)
    In:  CASI
    Details
    Publication Date: 2019-07-11
    Description: A wind-tunnel investigation of a 0.049-scale model of the Boeing XB-52 airplane was made at Mach numbers from 0.30 to 0.925 and at corresponding Reynolds numbers from about 2.3 x 10(exp 6) to 4.3 x 10(exp 6). The results of the investigation indicate satisfactory static longitudinal stability throughout the test Mach-number range and some loss in tail effectiveness beginning at about 0.80 Mach number. A comparison of the results of these tests with those of the same model in the Boeing Airplane Company's wind tunnel showed close agreement of lift- and drag-divergence Mach numbers. Slight differences were observed in tail effectiveness and the position of the stick-fixed neutral point.
    Keywords: Aerodynamics
    Type: NACA-RM-SA51C16
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 81
    facet.materialart.
    Unknown
    Aerodynamic Characteristics at High and Low Subsonic Mach Numbers of the NACA 0012, 64(sub 2)-015, and 64(sub 3)-018 Airfoil Sections at Angles of Attack from -2 Degrees to 30 Degrees (1954)
    In:  CASI
    Details
    Publication Date: 2019-07-11
    Description: An investigation has been made in the Langley low-turbulence pressure tunnel of the aerodynamic characteristics of the NACA 0012, 64(sub 2)-015, and 64(sub 3)-018 airfoil sections. Data were obtained at Mach numbers from 0.3 to that for tunnel choke, at angles of attack from -2deg to 30deg, and with the surface. of each airfoil smooth-and with roughness applied at the leading edge.The Reynolds numbers of the tests ranged from 0.8 x 10(exp 6) to 4.4 x 10(exp 6). The results are presented as variations of lift, drag, and quarter-chord pitching-moment coefficients with Mach number.
    Keywords: Aerodynamics
    Type: NACA-RM-L54H06a
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 82
    facet.materialart.
    Unknown
    Lateral Oscillatory Characteristics of the Republic F-91 Airplane Calculated by Using Low-Speed Experimental Static and Rotary Derivatives (1953)
    In:  CASI
    Details
    Publication Date: 2019-07-11
    Description: The present investigation was conducted to determine, from low-speed tests in the Langley stability tunnel, the static and rotary derivatives of a 1/9-scale model of the Republic F-91 airplane and various of its components (including the effects of wing incidence) and to determine the accuracy with which the period and damping of the lateral oscillation of the airplane could be calculated by using these experimentally between flight and calculated period and damping of the lateral oscillation were made for Mach numbers from 0.4 to 0.9 at an altitude of 20,OOO feet for 0deg wing incidence and several other wing incidences. Some comparisons were made of the static and rotary derivatives of the model and derivatives estimated by available procedures. determined derivatives (corrected for Mach number effects). Comparisons The results of the investigation have indicated that the model did not have unusual aerodynamic characteristics except for a large (about -0.125) increment in the damping in yaw contributed by the fuselage. Changes in wing incidence, in general, had little effect on the static and rotary derivatives of the model. The static and rotary derivatives of the model could be estimated with good accuracy only in the low angle-of-attack range by using available procedures.
    Keywords: Aerodynamics
    Type: NACA-RM-L53G01
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 83
    facet.materialart.
    Unknown
    Flight Characteristics of a 1/4-Scale Model of the XFV-1 Airplane (TED No. NACA DE-378) (1952)
    In:  CASI
    Details
    Publication Date: 2019-07-11
    Description: A l/4-scale dynamically similar model of the XFV-1 airplane has been flown in the Ames 40- by 80-foot wind tunnel, using the trailing flight-cable technique. This investigation was devoted to establishing the flight characteristics of the model in forward flight from hovering to wing stall, and in yawed flight (wing span alined with the relative wind) from hovering to the maximum speed at which controlled flight could be maintained. Landings, take-offs, and hovering characteristics in flights close to the ground were also investigated.. Since the remote control system for the model was rather complicated and provided artificial damping about the pitch, roll, and yaw axes, sufficient data from the control-system calibration tests are included in this report to specify the performance of the control system in relation to both the model flight tests and the design of an automatic control system for the full-scale airplane. The model in hovering flight appeared to be neutrally stable. The response of the model to the controls was very rapid, and it was always necessary to provide some amount of artificial damping to maintain control. The model could be landed with little difficulty by hovering approximately a foot above the floor and then cutting the power. Take-offs were more difficult to perform, primarily because the rate of change in power to the model motors was limited by the characteristics of the available power source. The model was,capable of controlled yawed flight at translational velocities up to and including 20 feet per second. The effectiveness of the controls decreased with increasing speed, however, and at 25 fps control in pitch, and probably roll, was lost completely. The model was flown in controlled forward flight from hovering up to 70 fps. During these flights the model appeared to be more difficult to control in yaw than it was in pitch or roll. The flights of the model were recorded by motion picture cameras. These motion pictures are available on loan from NACA Headquarters as a film supplement to this report.
    Keywords: Aerodynamics
    Type: NACA-RM-SA52J15
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 84
    facet.materialart.
    Unknown
    Small-Scale Transonic Investigation of the Effects of Partial-Span Leading-Edge Camber on the Aerodynamic Characteristics of a 50 Deg 38' Sweptback Wing of Aspect Ratio 2.98 (1952)
    In:  CASI
    Details
    Publication Date: 2019-07-11
    Description: A small-scale transonic investigation of two semispan wings of the same plan form was made in the Langley high-speed 7- by 10-foot tunnel through a Mach number range of 0.70 to 1.10 and a mean-test Reynolds number range of 745,000 to 845,000 to determine the effects of partial-span leading-edge camber on the aerodynamic characteristics of a swept-back wing. This paper presents the results of the investigation of wing-alone and wing-fuselage configurations of the two wings; one, was an uncambered wing and the other had the forward 45 percent of the chord cambered over the outboard 55 percent of the span. The semispan wings had 50deg 38ft sweepback of their quarter-chord lines, aspect ratio of 2.98, taper ratio of 0.45, and modified NACA 64A-series airfoil sections tapered in thickness ratio. Lift, drag, pitching moment, and root-bending moment were obtained for these configurations. The results indicated that, for the wing-alone configuration, use of the partial-span leading-edge camber provided an increase in maximum lift-drag ratios up to a Mach number of 0.95, after which no gain was realized. For the wing-fuselage combination, the partial-span leading-edge camber appeared to cause no gain in maximum lift-drag ratio throughout the test range of Mach numbers. The lift-curve slopes of the partial-span leading-edge camber configurations indicated no significant change over the basic configurations in the subsonic range but resulted in slight reductions at the higher Mach numbers. No significantly large changes in pitching-moment-curve slopes or lateral center of additional loading were indicated because of the modification.
    Keywords: Aerodynamics
    Type: NACA-RM-L52D08A
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 85
    facet.materialart.
    Unknown
    Effect of a Leading-edge Flap upon the Lift, Drag, and Pitching Moment of an Airplane Employing a Thin, Unswept Wing (1954)
    In:  CASI
    Details
    Publication Date: 2019-07-12
    Description: The effects of deflecting full-span, constant-chord, leading-edge flaps, having either round or sharp leading edges, upon the lift, drag,. and pitching moment characteristics of a model of an interceptor-type aircraft have been determined experimentally at subsonic and supersonic speeds. Results indicate that the variations of lift with angle of attack and of pitching moment with lift were unaffected by either the shape of the flap leading edge or flap deflection. Deflection of the flaps having either a round or sharp leading edge increased the drag at zero lift at both subsonic and supersonic speeds. In spite of the increase in the drag at zero lift, however, deflection of the flaps increased the maximum lift-drag ratio at subsonic speeds and had no deleterious effect at supersonic speeds.
    Keywords: Aerodynamics
    Type: NACA-RM-SA54B16
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 86
    facet.materialart.
    Unknown
    Wind-Tunnel Investigation of the Low-Speed Static Longitudinal Characteristics of the Republic RF-84F Airplane (1952)
    In:  CASI
    Details
    Publication Date: 2019-07-12
    Description: Tests in the Ames 40- by 80-foot wind tunnel of the static longitudinal characteristics of the Republic RF-84F were made to determine both the origin and a suitable remedy for a pitch up tendency of the airplane encountered at moderate lift coefficients. The results indicated that the pitch-up at moderate lift coefficients was caused by an abrupt change in downwash at the tail which in turn was traceable presumably to flow conditions associated with the inlet-to-wing leading-edge discontinuity.. Attempts to eliminate this pitch-up characteristic with various fairings and stall-control devices. were not wholly successful. The investigation revealed, however, that significant gains in the performance of the airplane could be achieved in the upper lift range.. Three different configurations consisting of a partial-span modified leading edge combined with one or with two-fenees or a leading-edge extension each delayed the onset of separation to higher lift coefficients and provided large improvements in the stability of the airplane in the upper lift range.
    Keywords: Aerodynamics
    Type: NACA-RM-SA52H04
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 87
    facet.materialart.
    Unknown
    Preliminary Altitude Performance Characteristics of the J57-P-1 Turbojet Engine with Fixed-area Exhaust Nozzle (1954)
    In:  CASI
    Details
    Publication Date: 2019-07-12
    Description: An investigation to determine the altitude performance of the J57-P-1 turbojet engine and components was conducted at the NACA Lewis altitude wind tunnel. Data were obtained over a corrected inboard rotor speed range from 56 to 106 percent of rated speed, with intercompressor bleeds both open and closed, at altitudes from 15,000 to 50,000 feet and at a flight Mach number of 0.81. The corresponding range of Reynolds number indices was from 0.858 to 0.213. All data presented were obtained with a fixed-area exhaust nozzle sized according to the manufacturer's specification. Over-all engine performance parameters are presented as functions of inboard rotor speed corrected on the basis of engine inlet temperature. Component parameters are presented as functions of their respective corrected rotor speeds. A tabulation of all performance data is included in addition to the graphical presentation. Corrected net thrust is unusually sensitive to changes in corrected inboard rotor speed in the high speed region. A change of 1 percent in speed, at sated speed, produced a change of 6 percent in corrected net thrust . At rated engine speed, increasing the altitude from 15,000 to 50,000 feet at a constant flight Mach number of 0.81 increased the specific fuel consumption 13 percent but did not affect corrected net thrust.
    Keywords: Aerodynamics
    Type: NACA-RM-SE54D30
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 88
    facet.materialart.
    Unknown
    Large-Scale Flight Measurements of Zero-Lift Drag at Mach Numbers from 0.90 to 1.95 of 1/14-Scale Model of the Northrop MX-775B Pilotless Aircraft with Small Body (1950)
    In:  CASI
    Details
    Publication Date: 2019-07-12
    Description: A flight test was made a t high subsonic, transonic, and supersonic speeds and at high Reynolds numbers to determine the zero-lift drag of a 1/14-scale model of the Northrop MX-775B pilotless aircraft with small small body. The triangular wing of the model had 67.5 deg leading-edge sweep and 15 deg. trailing-edge sweep, The wing airfoil sections were modified NACA 0004 sections. The drag coefficient based on total wing area was 0.0107 at Mach number 1.60. At transonic speeds the maximum drag coefficient was 0.0125. The force-break Mach number was 0,98.
    Keywords: Aerodynamics
    Type: NACA-RM-SL50H18
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 89
    facet.materialart.
    Unknown
    Supplementary Free-Spinning-Tunnel Investigation of a 1/30-Scale Model of the Grumman XF10F-1 Airplane in the Swept-Wing Configuration with Slats Extended (1951)
    In:  CASI
    Details
    Publication Date: 2019-07-12
    Description: A supplementary investigation has been conducted in the Langley 20-foot free-spinning tunnel of a 1/30 -scale model of the Grumman XFlOF-1 airplane to determine what effect full-span slats would have on the spin-recovery characteristics of the swept-wing version of the XFlOF-1 airplane, which had previously been indicated as possessing undesirable spin-recovery characteristics without slats. The effects of extended nose-wheel doors and of fairing the air-duct inlets were also determined. The results indicated that, with slats fully extended, satisfactory recovery could be obtained by rudder reversal provided it was accompanied by movement of the trimmer ailerons to full with the spin (only up-going spoiler operative), Extension of the nose-wheel doors or fairing of the air-duct inlets did not improve the recovery characteristics.
    Keywords: Aerodynamics
    Type: NACA-RM-SL51G19
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 90
    facet.materialart.
    Unknown
    An Exploratory Investigation of Some Types of Aeroelastic Instability of Open and Closed Bodies of Revolution Mounted on Slender Struts (1953)
    In:  CASI
    Details
    Publication Date: 2019-07-12
    Description: Aeroelastic instability phenomena of isolated open and closed rigid bodies of revolution free to move under elastic restraint have been investigated experimentally at low speeds by means of models suspended at zero angles of attack and yaw on slender flexible struts from a wind tunnel ceiling. Three types of instability were observed - flutter similar to classical bending-torsion flutter, divergence, and an uncoupled oscillatory instability which consists in nonviolent continuous or intermittent small-amplitude oscillations involving only angular deformations. The speeds at which this oscillatory instability starts were found to be as low as about one-third of the speed at flutter or divergence and to depend on the shape of the body, particularly that of the afterbody, and on the relative location of the elastic axis. An attempt has been made to calculate the airspeeds and, in the case of the oscillatory phenomena, the frequencies at which these instabilities occur by using slender-body theory for the aerodynamic forces on the bodies and neglecting the aerodynamic forces on the struts. However, the agreement between the speeds and frequencies calculated in this manner and those actually observed has been found to be generally unsatisfactory; with the exception of the frequencies of the uncoupled oscillations which could be predicted with fair accuracy. The nature of the observed phenomena and of the forces on bodies of revolution suggests that a significant improvement in the accuracy of analytical predictions of these aeroelastic instabilities can be had only by taking into account the effects of boundary-layer separation on the aerodynamic forces.
    Keywords: Aerodynamics
    Type: NACA-RM-L53E07
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 91
    facet.materialart.
    Unknown
    Damping in a Roll of a Missile Configuration with a Modified Triangular Wing and a Cruciform Tail at a Mach Number of 1.52 (1951)
    In:  CASI
    Details
    Publication Date: 2019-08-14
    Description: The damping-in-Toll stability derivatives of a missile configuration and its components were determined both experimentally and theoretically. The tests were conducted at a Mach number of 1.52 and at a Reynolds number, based on the mean aerodynamic chord of the wing, of 0.82 x 10(exp 6). The experimental damping derivative of the wing-body combination was 67 percent of the theoretical value. The difference is believed to have resulted mainly from the fact that the theory is not strictly applicable when the Mach number normal to the leading edge is almost unity, which was the case in the present investigation. For the tail-body combination the damping derivative was 86 percent of the theoretical value. In this case, the difference is believed to have been caused partially by mutual interference between the tail surfaces and partially by the low Reynolds number of the flow over the tail. It was found that the damping of the complete configuration was not equal to the sum of the damping derivatives of the components because of the effect of the wing downwash on the damping of the tail.
    Keywords: Aerodynamics
    Type: NACA-RM-A51A03
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 92
    facet.materialart.
    Unknown
    Spinning Characteristics of Wings III : a Rectangular and Tapered Clark Y Monoplane Wing with Rounded Tips (1937)
    In:  CASI
    Details
    Publication Date: 2019-08-14
    Description: An investigation was made to determine the spinning characteristics of Clark Y monoplane wings with different plan forms. A rectangular wing and a wing tapered 5:2, both with rounded tips, were tested on the N.A.C.A. spinning balance in the 5-foot vertical wind tunnel. The aerodynamic characteristics of the models and a prediction of the angles of sideslip for steady spins are given. Also included is an estimate of the yawning moment that must be furnished by the parts of the airplane to balance the inertia couples and wing yawing moment for spinning equilibrium. The effects on the spin of changes in plan form and of variations of some of the important parameters are discussed and the results are compared with those for a rectangular wing with square tips. It is concluded that for a conventional monoplane using Clark Y wing the sideslip will be algebraically larger for the wing with the rounded tip than for the wing with the square tip and will be largest for the tapered wing. The effect of plan form on the spin will vary with the type of airplane; and the provision of a yawing-moment coefficient of -0.025 (i.e., opposing the spin) by the tail, fuselage, and interference effects will insure against the attainment of equilibrium on a steady spin for any of the plan forms tested and for any of the parameters used in the analysis.
    Keywords: Aerodynamics
    Type: NACA-TN-612
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 93
    facet.materialart.
    Unknown
    Lift, Drag, and Pitching Moment of Low-Aspect-Ratio Wings at Subsonic and Supersonic Speeds: Triangular Wing of Aspect Ratio 2 with NACA 0005-63 Thickness Distribution, Cambered and Twisted for a Trapezoidal Span Load Distribution (1951)
    In:  CASI
    Details
    Publication Date: 2019-08-17
    Description: A wing-body combination having a plane triangular wing of aspect ratio 2 with NACA 0005-63 thickness distribution in streamwise planes, and twisted and cambered for a trapezoidal span load distribution has been investigated at both subsonic and supersonic Mach numbers. The lift, drag, and pitching moment of the model are presented for Mach numbers from 0.60 to 0.90 and 1.30 to 1.70 at a Reynolds number of 3.0 million. The variations of the characteristics with Reynolds number are also shown for several Mach numbers.
    Keywords: Aerodynamics
    Type: NACA-RM-A50K27a
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 94
    facet.materialart.
    Unknown
    Tests at Mach Number 1.62 of a Series of Missile Configurations Having Tandem Cruciform Lifting Surfaces (1952)
    In:  CASI
    Details
    Publication Date: 2019-08-14
    Description: An investigation at a Mach number of 1.62 was made in the Langley 9-inch supersonic tunnel of a series of missile configurations having tandem lifting surfaces of low aspect ratio and of newly equal span. Some of the variables investigated were interdigitation angle, wing and tail plan form, and longitudinal location of wing with respect to tail. All configurations were tested through an angle-of-attack range from -5 deg to 15 deg at roll angles of 0 deg and 45 deg. Lift, drag, and pitching moment data are presented, together with center-of-pressure locations and tail-lift efficiency factors.
    Keywords: Aerodynamics
    Type: NACA-RM-L51J15
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 95
    facet.materialart.
    Unknown
    Tests of Several Model Nacelle-Propeller Arrangements in Front of a Wing (1939)
    In:  CASI
    Details
    Publication Date: 2019-08-27
    Description: An investigation was conducted in the N.A.C.A. 20-foot wind tunnel to determine the drag, the propulsive and net efficiencies, and the cooling characteristics of severa1 scale-model arrangements of air-cooled radial-engine nacelles and present-day propellers in front of an 18- percent-thick, 5- by 15-foot airfoil. This report deals with an investigation of wing-nacelle arrangements simulating the geometric proportions of airplanes in the 40,000- to 70,000- pound weight classification and having the nacelles located in the vicinity of the optimum location determined from the earlier tests.
    Keywords: Aerodynamics
    Type: NACA-SR-123
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 96
    facet.materialart.
    Unknown
    Flight Test Results of Rocket-Propelled Buffet-Research Models Having 45 Degree Sweptback Wings and 45 Degree Sweptback Tails Located in the Wing Chord Plane (1953)
    In:  CASI
    Details
    Publication Date: 2019-07-11
    Description: Three rocket-propelled buffet-research models have been flight tested to determine the buffeting characteristics of a swept-wing- airplane configuration with the horizontal tail operating near the wing wake. The models consisted of parabolic bodies having 45deg sweptback wings of aspect ratio 3.56, at aspect ratio of 0.3, NACA 64A007 airfoil sections, and tail surfaces of geometry and section identical to the wings. Two tests were conducted with the horizontal tail located in the wing chord plane with fixed incidence angles of -1.5deg on one model and 0deg on the other model. The third test was conducted with no horizontal tail. Results of these tests are presented as incremental accelerations in the body due to buffeting, trim angles of attack, trim normal- and side-force coefficients, wing-tip helix angles, static-directional-stability derivatives , and drag coefficients plotted against Mach number. These data indicate that mild low-lift buffeting was experienced by all models over a range of Mach number from approximately 0.7 to 1.4. It is further indicated that this buffeting was probably induced by wing-body interference and was amplified at transonic speeds by the horizontal tail operating in the wing wake. A longitudinal trim change was encountered by the tail-on models at transonic speeds, but no large changes in side force and no wing dropping were indicated.
    Keywords: Aerodynamics
    Type: NACA-RM-L53I10
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 97
    facet.materialart.
    Unknown
    Investigation of the Attenuation of Plane Shock Waves Moving over very Rough Surfaces (1953)
    In:  CASI
    Details
    Publication Date: 2019-07-11
    Description: Experimental measurements of the attenuation of plane shock waves moving over rough walls have been made in a shock tube. Measurements of the boundary-layer characteristics, including thickness and velocity distribution behind the shock, have also been made with the aid of new cal techniques which provide direct information on the local boundary-layer conditions at the rough walls. Measurements of shock speed and shock pressure ratio are presented for both smooth-wall and rough-wall flow over lengths of machined-smooth and rough strips which lined all four walls of the shock tube. A simplified theory based on Von Karman's expression for skin-friction coefficient for flow over rough walls, along with a wave-model concept and extensions to include time effects, is presented. In this theory, the shock-tube flow is assumed to be one-dimensional at all times and the wave-model concept is used to relate the local layer growth to decreases in shock strength. This concept assumes that local boundary-layer growths act as local mass-flow sinks, which give rise to expansion waves which, in turn, overtake the shock and lower its mass flow accordingly.
    Keywords: Aerodynamics
    Type: NACA-RM-SL53D13A
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 98
    facet.materialart.
    Unknown
    Tests of a Hermes A-2 Missile Body at Mach Number 4.04 (1950)
    In:  CASI
    Details
    Publication Date: 2019-07-11
    Description: Force tests on a proposed body shape of the Hermes A-2 missile with and without longitudinal spoilers were made at Mach number 4.04. Values of normal force coefficient, pitching-moment coefficient, and center-of-pressure position were obtained.
    Keywords: Aerodynamics
    Type: NACA-RM-SL50H23A
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 99
    facet.materialart.
    Unknown
    An Approximate Method of Calculating the Deformations of Wings Having Swept, M or W, A, and Swept-Tip Plan Forms (1952)
    In:  CASI
    Details
    Publication Date: 2019-07-11
    Description: An approximate method of calculating the deformations of wings of uniform thickness having swept, M or W, Delta, and swept-tip plan forms is presented. The method employs an adjustment to the elementary beam theory to account for the effect of the triangular root portion of a swept wing on the deformation of the outboard section of the wing. To demonstrate the general applicability of the method, the modified elementary theory is applied to the more complex M or W, Delta, and swept-tip plan forms as well as to swept plan forms. For the purpose of calculating angles of attack, it is shown that the unmodified elementary beam theory applied to that part of the wing outboard of the root triangle produces satisfactory results. However, for calculating deflections it is necessary to include the effects of the root-triangle deformation.
    Keywords: Aerodynamics
    Type: NACA-RM-L53A23
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 100
    facet.materialart.
    Unknown
    Aerodynamic Characteristics of a Flying-Boat Hull Having a Length-Beam Ratio of 15, TED No. NACA 2206 (1951)
    In:  CASI
    Details
    Publication Date: 2019-07-11
    Description: An investigation was made in the Langley 300 MPH 7- by 10-foot tunnel to determine the aerodynamic characteristics of a flying-boat hull of a length-beam ratio of 15 in the presence of a wing. The investigation was an extension of previous tests made on hulls of length-beam ratios of 6, 9, and 12; these hulls were designed to have approximately the same hydrodynamic performance with respect to spray and resistance characteristics. Comparison with the previous investigation at lower length-beam ratios indicated a reduction in minimum drag coefficients of 0.0006 (10 peroent)with fixed transition when the length-beam ratio was extended from 12 to 15. As with the hulls of lower length-beam ratio, the drag reduction with a length-beam ratio of 15 occurred throughout the range of angle of attack tested and the angle of attack for minimum drag was in the range from 2deg to 3deg. Increasing the length-beam ratio from 12 to 15 reduced the hull longitudinal instability by an mount corresponding to an aerodynamic-center shift of about 1/2 percent of the mean aerodynamic chord of the hypothetical flying boat. At an angle of attack of 2deg, the value of the variation of yawing-moment coefficient with angle of yaw for a length-beam ratio of 15 was 0.00144, which was 0.00007 larger than the value for a length-beam ratio of 12.
    Keywords: Aerodynamics
    Type: NACA-RM-L6J24
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...