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  • 1
    ISSN: 1573-4803
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract We report here on the dielectric properties (dielectric constant, ɛ′ and dielectric losses ɛ″), magnetic properties (μ′ and μ″), infrared spectroscopic, thermal studies (thermogravimetric analysis (TGA)), differential thermogravimetry (DTG) and differential scanning calorimetry (DSC) and X-ray diffraction (XRD) for the polycrystalline powdered samples of manganese tartrate MnC4H4O6·2H2O obtained by diffusion of manganese ions through silica gel impregnated with tartaric acid. The aforementioned properties are used as a probe for the detection and study of the different transitions that have been found in this salt. Energy dispersive analysis of X-rays (EDAX) confirmed the presence of manganese. X-ray diffraction data giving 2gq, intensity andd-values are reported for the first time. Infrared wavelengths in the range 500–4000 cm−1 and the description of peaks recorded for the material are given. Results of thermal analysis indicated that the material is thermally unstable. Dielectric and magnetic measurements were determined in the frequency range of 45 MHz to 2 GHz.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1570-7458
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Summary In order to determine if sex trapping could be utilised as a method of studying the dispersal of S. cerealella, 120 males reared in the laboratory were released and caught in a sex trap containing 100 virgin females. This first experiment took place in April 1968, outside the normal period of insect activity in nature. During the 10 days following the male release, we caught, at dusk, 40 males in this sex trap (30% of the release). This method was later used to determine the life cycle of the Angoumois grain moth in South-West France. S. cerealella appears in late May and early June in nature. It appears to produce three generations a year. The first and the second would be passed either on maize in cribs or stores, or on other cultivated or wild Graminaceae; on the other hand, the third generation would be spent on ears of maize in the fields. Among the climatic factors which influence the trapping rates of males, daylight seems the most important. The males are trapped only at dusk and for a period of about one hour. Temperature, aerial-humidity, and wind are not negligible. The sex attractiveness of virgin females seems such as to draw males from considerable distances: an experiment with several sex traps, each containing 5 virgin females only, has proved that it was possible to trap males at several hundred metres from the release point. Among biotic factors excluding those pertaining to the insect itself, the host-plant seems to be the principal factor for the number of trapped males. The maize has adouble effect by its mere presence and its phenological stage: continuous trapping from June to November by two sex traps on uncultivated fields and two other sex traps on maize fields gave respectively the following results: 393 and 6520 males. The experiment of trapping males after release in uncultivated areas and in corn fields gave the following results (% of males covered), for the three periods studied: July 9–13 whorl stage: 7.3% August 27–31 late tasseling and silking stage: 19.6% October 4–8 milking stage of kernels, maturity: 19.0%
    Notes: Résumé Après avoir mis en évidence, par une expérience préliminaire, l'efficacité du piégeage sexuel chez S. cerealella, en dehors de sa période normale d'activité, l'auteur a utilié cette méthode au cours des années 1968, 1969 et 1970 pour préciser le cycle biologique de cette espèce dans le Sud-Ouest de la France. A cette occasion, l'action de différents facteurs sur le rendement du piégeage sexuel a pu être étudiée. Parmi les facteurs physiques, le plus important paraît être la luminosité: c'est au crépuscule, pendant une heure environ, que se font les captures. Parmi les facteurs biotiques, la présence de la plante-hôte, le Maïs, et le stade phénologique de celle-ci ont une action déterminante sur le taux des captures: ces dernières sont plus nombreuses à partir de la floraison mâle jusqu'à l'approche de la maturité des grains.
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  • 3
    ISSN: 1573-1561
    Keywords: Pyralidae ; Ostrinia nubilalis ; oviposition preference ; corn silk volatile chemicals ; extraction ; desorption ; gas chromatography ; mass spectrometry alkanes ; phenylacetaldehyde
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The noncontingent distribution ofO. nubilalis Hbn. eggs on various corn varieties has allowed their classification as either “favorable” or “nonfavorable” hybrids. This classification is based on a chemical communication system using volatile compounds active at a distance from the insect or active when in contact with the insect as soluble sugar components. Under this hypothesis, gas chromatography is the best way of investigating for the chemical differences between corn silk extracts from the two types of hybrids. A first experiment, using a “desorption-trapping” system on Tenax coupled to a gas chromatograph showed a quantitative difference between two compounds from the two hybrids. A second experiment showed the advantages and disadvantages of this method and allowed the development of two complementary techniques: (1) direct extraction of corn silk with trichlorofluo-romethane and direct injection into a capillary column with an apolar stationary phase using an “on-column” system; and (2) extraction under vacuum of volatile compounds from corn silk and their trapping on Tenax, followed by a second desorption. This allows a direct injection on the same capillary column. The first technique allows identification by mass spectrometry of many alkanes with high molecular weights. The second technique seems to confirm the presence of phenylacetaldehyde. Both techniques show quantitative differences in the composition of corn silk extracts from “favorable” and “nonfavorable” hybrids; however, the biologically active chemicals remain unknown.
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  • 4
    ISSN: 1573-1561
    Keywords: Lobesia botrana ; European grape moth ; sex pheromone ; mating disruption ; insect marking technique
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Disruption experiments were carried out under vineyard conditions and in the laboratory. Males from laboratory cultures were conditioned in an atmosphere permeated with pheromone (E7 Z9-12Ac), marked externally with fluorescent powder, and released in the middle of vine plots. They were then trapped in a series of traps baited with virgin females or dispensers loaded with various amounts of pheromone. Over 10,000 males were released in these experiments between 19 May and 22 July. Electroantennography tests were used for studying olfactory sensitivity in pheromone-permeated air by measuring the EAG responses of male antennae in constant pheromone air-flows. The conclusion is that both sensory adaptation and central nervous system habituation mechanisms acted simultaneously in air laden with pheromone, but they are probably not relevant when concentrations are of the same order of magnitude as those obtained under field conditions in which mating disruption methods are used for controlling the European grape moth.
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  • 5
    ISSN: 1573-6857
    Keywords: Drosophila melanogaster ; isofemale lines ; isogroups ; natural populations ; pigmentation ; body size
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Studies of short or medium range geographic variations play an increasing role in ecological genetics, and sensitive techniques are required to detect them. In this respect, two sampling techniques were compared inD. melanogaster. The biological data were provided by the analysis of four natural populations from the same geographic area, Spain (one) and Southern France (three), for four morphometrical traits: abdomen and thoracic pigmentation, and wing and thorax lengths. Traits were measured on wild living females and on their progeny reared in the laboratory at 25°C. For progeny analyses, two techniques were compared: the usual isofemale line technique, sib families issued from a single female, and a new isogroup technique, the progeny produced by a group of 20 wild-collected parents. Large phenotypic variations were observed in wild living flies, corresponding to the unstability of natural environmental conditions during their development. Among laboratory grown flies, variations were much smaller. Between isogroups, differences were small, due to sampling error and some common environment effects. Variations between lines were much greater, thus demonstrating a strong genetic component. When different populations have to be compared, the isogroup technique should be preferred since, for the same amount of work, the lesser variability between groups provides a more precise characterization of the population means.
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  • 6
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 84 (1998), S. 5729-5732 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Polycrystalline samples of dimeric cadmium tartrate, [(Cd,C4H4O6)2H2O)]3H2O [labeled CdT(I)], were studied using impedance measurements and x-ray powder diffraction. The dependence of the real part of the dielectric constant on temperature showed a sharp peak at about 65 °C, revealing a structural phase transition, while the other broad peak in the temperature range (70〈T〈85 °C) was due to the loss of water molecules. The x-ray powder diffraction patterns at three temperatures (25, 60, and 70 °C) are consistent with three nonequivalent space groups. According to these results, it seems that this compound undergoes two successive phase transitions: P212121→P21→Pnmn, suggesting an intermediate ferroelectric behavior, labeled CdT(II) between a paraelectric CdT(I) and an anhydrous phase, labeled CdT(III). © 1998 American Institute of Physics.
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  • 7
    ISSN: 0022-474X
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
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  • 8
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] The idea that iron might limit phytoplankton growth in large regions of the ocean has been tested by enriching an area of 64 km2 in the open equatorial Pacific Ocean with iron. This resulted in a doubling of plant biomass, a threefold increase in chlorophyll and a fourfold increase ...
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  • 9
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    In:  CASI
    Publication Date: 2006-01-12
    Description: The performance of the nickel hydrogen batteries on board the NTS-2 satellite was determined after being in orbit for several months. The effects of the eclipses were presented as well as the power loading operations.
    Keywords: ENERGY PRODUCTION AND CONVERSION
    Type: NASA. Goddard Space Flight Center 11th Ann. Battery Workshop; p 309-315
    Format: text
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  • 10
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    In:  Other Sources
    Publication Date: 2016-06-07
    Description: Data concerning a ten cell nickel hydrogen battery are presented. The plates are electrochemically impregnated using slurry plaque.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA. Goddard Space Flight Center The 1981 GSFC Battery Workshop; p 481-485
    Format: text
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