Library

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
  • Polymer and Materials Science  (127)
  • Life and Medical Sciences  (114)
  • Engineering General  (43)
  • Biochemistry and Biotechnology  (33)
  • Analytical Chemistry and Spectroscopy  (30)
  • Coleoptera  (5)
Material
Keywords
  • 1
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 14 (1979), S. 1785-1804 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: Several types of smoothing technique are considered which generate continuous approximation (i.e. nodal values) for vorticity and pressure from finite element solutions of the Navier-Stokes equations using quadrilateral elements. The simpler schemes are based on combinations of linear extrapolation and/or averaging algorithms which convert elementwise. Gauss point values to nodal point values. More complicated schemes, based on a global smoothing technique which employ the mass matrix (consistent or lumped), are also presented.An initial assessment of the accuracy of the several schemes is obtained by comparing the approximate vorticities with an analytical function. Next, qualitative vorticity comparisons are made from numerical solutions of the steady-state driven cavity problem. Finally, applications of smoothing techniques to discontinuous pressure fields are demonstrated.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 7 (1987), S. 371-394 
    ISSN: 0271-2091
    Keywords: Consistent Flux ; Heat Flux ; Derived Quantities ; FEM ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: A consistent, accurate and reasonably simple method of obtaining derived quantities when the conventional Galerkin finite element method (GFEM) is used to obtain the primary quantities is defined and demonstrated, both theoretically and numerically.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 39 (1959), S. 249-268 
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The overall rate of polymerization of styrene and isoprene with the heterogeneous allylsodium-sodium isopropoxide-sodium chloride (Alfin PP) system as initiator is reaction-controlled and is first order with respect to monomer and proportional to the amount of initiator present. The intrinsic viscosity of the product is independent of the monomer and initiator concentrations. The rate of styrene polymerization is independent of alkoxide concentration over a certain range, while the intrinsic viscosity increases with increasing alkoxide concentration. The activation energy of the overall rate is about 12 kcal./mole for styrene and 10 kcal./mole for isoprene. The simplest explanation of the kinetic results assumes initiation and termination steps involving the monomer. The distribution of molecular weights in Alfin polystyrene appears very broad. The kinetic features of this reaction bear a strong resemblance to those of the formation of isotactic polymers from the alkyl aluminum-titanium chloride system (Ziegler catalyst.)
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1570-7458
    Keywords: Coleoptera ; Chrysomelidae ; Leptinotarsa decemlineata ; Colorado potato beetle ; Solanaceae ; Solanum berthaultii ; potato ; plant resistance ; selection ; adaptation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Thirty cohorts of the Colorado potato beetle (CPB) were reared for ten consecutive generations on the cultivated potato,Solanum tuberosum, and on two accessions (PI 473331 and PI 473334) of the resistant wild species,S. berthaultii. At each generation, selection was imposed for increased survival, decreased development time, and for increased fecundity. Although several parameters responded to selection, net replacement rate (R0) onS. berthaultii was consistently less than 1/3 that on cultivated potato. At the tenth generation, eachS. tuberosum strain female replaced herself with 110 daughters, whereas females from strains reared on PI 473334 and PI 473331 produced an average of 30 and 7 daughters, respectively. Slopes of the R0 regression lines for populations reared onS. tuberosum andS. berthaultii did not differ from zero, indicating no significant response to selection. Our findings suggest that populations of the Colorado potato beetle may have genetic variability in some performance traits for adaptation toS. berthaultii, but that adaptation is unlikely to occur as rapidly as previously reported.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1423-0445
    Keywords: kairomone ; behavior ; cucurbitacin ; Cucurbitaceae ; Coleoptera ; Chrysomelidae ; Luperini ; Aulacophora ; Diabrotica
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The attraction of Old World leaf beetles in the genusAulacophora to kairomones and parakairomones which are effective lures for New WorldDiabrotica andAcalymma were investigated. Beetles captured on sticky traps baited with single and multicomponent lures were no different from the control traps for two species ofAulacophora. Yellow colored traps and squash blossoms are attractive toAulacophora beetles which detect sub-microgram quantities of cucurbitacins on silica gel. Leaf feeding behavior and flight activity data are correlated with varietal preference of threeAulacophora species. The common response byDiabrotica andAulacophora to cucurbitacins reinforces the two groups' coevolutionary association with the Cucurbitaceae. The apparent lack of a common response toCucurbita blossom volatiles suggests recent evolutionary pathways are substantially different for these two groups of beetles.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Journal of chemical ecology 11 (1985), S. 1371-1387 
    ISSN: 1573-1561
    Keywords: Asymmetric synthesis ; stereoisomers ; sex pheromone ; Diabrotica ; Coleoptera ; Chrysomelidae ; (R)-2-methylbutyric acid ; HPLC ; diastereomers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Details of the syntheses of the four stereoisomers of 8-methyl-2-decanol and its propanoate ester are given. The racemic ester, two of its stereoisomers, and one stereoisomer as an acetate are attractive to several species ofDiabrotica. The key steps in the syntheses involve high-performance liquid chromatograpic resolutions of diastereomers to achieve high configurational enrichment of each site and generation of (R)-2-methylbutyric acid by chemical degradation ofd-isoleucine.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Journal of chemical ecology 12 (1986), S. 1109-1124 
    ISSN: 1573-1561
    Keywords: Rootworm beetle ; Diabrotica spp ; Aulacophora spp ; Coleoptera ; Chrysomelidae ; Cucurbita spp ; Cucumis spp ; cucurbitacin, allomone ; kairomone ; Chinese mantis ; Tenodera aridifolia sinensis ; predator ; Orthoptera ; Mantidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The cucurbitacins are oxygenated tetracyclic triterpenoids produced as secondary plant compounds by nearly all genera of Cucurbitaceae. The very bitter and toxic cucurbitacins are effective semiochemicals acting ecologically as allomones to protect the Cucurbitaceae from attack by a variety of invertebrate and vertebrate herbivores. For the Luperini (Coleoptera: Chrysomelidae: Galerucinae) the cucurbitacins have become kairomones for host selection, affecting the behavior of this large group of 1500 species of Aulacophorina (Old World) and Diabroticina (New World) by arrest and compulsive feeding. When feeding on bitter cucurbits these beetles sequester large amounts of cucurbitacins in their blood and tissues, and these act as allomones to deter predation. Specific detoxification and excretory mechanisms of the Diabroticina enable these beetles to avoid the toxic effects of the cucurbitacins.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Journal of chemical ecology 21 (1995), S. 1149-1162 
    ISSN: 1573-1561
    Keywords: Kairomonal attractants ; Diabroticite beetles ; Coleoptera ; Chrysomelidae ; olfactory synergism ; trimethoxybenzene ; indole ; cinnamaldehyde ; 4-methoxycinnamaldehyde ; 4-methoxyphenethanol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Olfactory synergism, where combinations of plant volatile kairomones are quantitatively more attractive to insects than the sum of attraction of the individual components, is an important but little-studied phenomenon in host plant selection and feeding and in pollination ecology. Diabroticite beetles (Coleoptera: Chrysomelidae) are strongly attracted toCucurbita blossoms, and 2- to 3-fold olfactory synergism has been demonstrated in four species by combinations of the key blossom volatiles, 1,2,4-trimethoxybenzene, indole, and (E)-cinnamaldehyde. This TIC mixture represents an optimizedCurcurbita blossom volatile kairomone mixture useful in monitoring Diabroticite populations and in studying their behavior and ecology. Indole, which exhibits a spectrum of attraction to these beetles ranging from moderate forDiabrotica virgifera virgifera andAcalymma vittatum to very weak forD. barberi, is the primary synergistic component. Indole combined with 4-methoxycinnamaldehyde was significantly synergistic toD. v. virgifera at a ratio of 1:300 and produced 4-fold synergism at a ratio of 1:1. Indole combined with 4-methoxyphenethanol was less synergistic toD. barberi with 1.5- to 2-fold synergism at a 1:1 ratio. These consistent variations in diabroticite beetle olfactory responses presumably indicate evolutionary divergences in the numbers of relict indole antennal receptors.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Biopolymers 2 (1964), S. 231-236 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The electrophoretic mobility of DNA in the presence of tetramethylammonium and alkali metal ion chlorides has been studied as a function of ionic strength. Each cation exhibits a characteristic behavior in accord with the idea that the order of inter-action with DNA is Li+ 〉 Na+ 〉 K+ 〉 TMA+. The application of theories of the electrophoresis of polyelectrolytes is discussed, leading to an attempt to calculate the fractional charge per DNA phosphorus from the mobility data. Over the range 0.05-0.4M a constant and unique value of the DNA charge is obtained in the presence of each cation. Values of the zeta potential and of the friction factor per monomer unit are also calculated.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Biopolymers 3 (1965), S. 491-496 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Calorimetric measurements of the heat of the addition of the second strand of poly U to poly (A + 2U) to form the three-stranded poly (A + 2U) complex in 0.1M and 0.5M NaCl at 24 and 37°C. are reported. A value of ΔH = -3800 cal./mole of poly (A + 2U) formed was found to be fairly insensitive to the experimental conditions employed. The heat of the addition of the third strand to the preformed poly (A + U) helix is considerably less exothermic than the heat of reaction between poly A and poly U to form poly (A + U). The insensitivity of the heat of addition of the third strand (poly U) to changes in salt concentration and temperature lends qualitative support to the earlier hypothesis that the major portion of the variation of the ΔH of the poly A and poly U reaction with experimental conditions arises from differences in the conformation of poly A. Combining the information obtained in this study for the ΔH of the reaction forming poly (A + 2U) with data for the ΔH of the formation of poly (A + U) indicates that the conversion of poly (A + U) to poly (A + 2U) is opposed by an enthalpy change which increases with temperature. Extrapolation of these values to 52°C. where poly (A + U) is transformed to poly (A + 2U) in 0.5M NaCl leads to a value of ΔH = +3800 cal./mole (A + 2U) formed and ΔS = 11.5 cal./mole of (A + 2U) formed. It is concluded from the calorimetric data that the driving force for the poly (A + U) to poly (A + 2U) conversion reaction is the favorable entropy change.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...