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  • Polymer and Materials Science  (5)
  • Panonychus ulmi  (2)
  • 1
    ISSN: 1572-9702
    Keywords: Tetranychus urticae ; Panonychus ulmi ; Petri dish bioassay ; propargite ; precision
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The effect of interval space between the concentration (symmetric or geometric), number of concentrations and overall sample sizes were investigated using a Petri dish bioassay, the miticide propargite and two spider mites species. The precision (width of the 95% confidence intervals) of the LC50 and LC90 estimates was shown to be influenced by the test design and total sample size The results suggest that a symmetric five-concentration design using a minimum total sample size of 480 mites is required to produce reliable LC estimates using the Petri dish method. Asymmetric designs did not increase the reliability of LC estimates. When less than 480 test subjects are available, a symmetric three-concentration design would give adequate LC estimates, but the precision would be less than with a five-concentration design.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Experimental and applied acarology 19 (1995), S. 549-570 
    ISSN: 1572-9702
    Keywords: Fluvalinate ; Tetranychus urticae ; Panonychus ulmi ; toxicity ; dispersal ; development rate ; oviposition ; sublethal effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Four fluvalinate formulations differed in their residual toxicity to female two-spotted spider mite (TSM), Tetranychus urticae adults; the emulsifiable concentrate (EC) was the most toxic. In contrast, there was little difference in toxicity between the formulations with the European red mite (ERM) Panonychus ulmi with the exception of the EC formulation which was the least toxic. Fluvalinate 2F caused minimal (〈10%) TSM and ERM egg mortality. Fluvalinate 2F was more toxic and caused greater larval dispersal for the TSM compared to the ERM at the field concentration and below. The toxicity of fluvalinate 2F to TSM and ERM protonymphs, deutonymphs and adults was low, approximately 〈20% at field concentration. Dispersal was the main response to fluvalinate and this was positively correlated with increasing concentration. The combined mortality and dispersal LC50 was five times lower for ERM protonymphs and adults, but 11 times higher for ERM deutonymphs compared to equivalent TSM life stages. Fluvalinate 2F reduced TSM development from the protonymph and deutonymph stages to a greater extent compared to the ERM. The mortality response to fluvalinate 2F was unaffected by host type (peach or apple) for the TSM whereas ERM mortality was higher on apple compared to peach. TSM dispersal was higher from apple compared to peach whereas ERM dispersal was similar on both host types. Oviposition by both mite species was lower on apple than peach leaves. A 1 h exposure to fluvalinate 2F reduced ERM oviposition for 12 days.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Biopolymers 7 (1969), S. 527-537 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Dilatometric measurements were made to determine the change in apparent specific volume ϕ of DNA resulting from thermal denaturation in neutral solution, ϕ increased continuously with temperature in the range 10-85°C. No deviations from a monotonically rising curve were observed in the ϕ versus temperature profile in the region of the melting temperature. The results are interpreted in terms of a partial loss of the preferentially bound DNA hydration shell. The nature of the well known buoyant density difference between native and denatured DNA was investigated by evaluating the densities in a series of cesium salt gradients at constant temperature. Extrapolation of the results to zero water activity indicates that the partial specific volumes of anhydrous native and denatured DNA are equal. The density difference at nonzero water activities is attributed to decreased hydration in the denatured state. The absence of a related change in ϕ accompanying the denaturation in the dilatometric experiments suggests that the probable volume change associated with loss of bound water during denaturation is accompanied by other compensatory volume effects. The possible nature of these volume effects is discussed.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Biopolymers 9 (1970), S. 445-457 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The change in apparent molal volume φ of DNA on thermal denaturation in carbonate buffer at pH 11.0 has been determined by the dilatometric method. It was found that φ increases sigmoidally during the helix-coil transition. Several methods, including a colorimetric technique that closely simulates the conditions used in the dilatometric experiments, were employed to estimate the protons lost by the DNA during the transition. These measurements indicated that the extent of the proton loss depends on the counterion present, increasing in the order Li+ 〈 Na+ 〈 K+ 〈 Cs+. The major part of the volume changes observed during the denaturation is due to the volume changes expected to accompany the transfer of protons from the bases guanine and thym ne to carbonate ions. As has been previously reported for the denaturation of DNA at neutral pH, the volume change directly due to the change in shape of the polymer molecules is so small as to be experimentally undetectable.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 4 (1966), S. 29-57 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The γ-radiation-induced free-radical copolymerization of ethylene and CO has been investigated over a wide range of pressure, initial gas composition, radiation intensity, and temperature. At 20°C., concentrations of CO up to 1% retard the polymerization of ethylene. Above this concentration the rate reaches a maximum between 27.5 and 39.2% CO and then decreases. The copolymer composition increases only from 40 to 50% CO when the gas mixture is varied from 5 to 90% CO. A relatively constant reactivity ratio is obtained at 20°C., indicating that CO adds 23.6 times as fast as an ethylene monomer to an ethylene free-radical chain end. For a 50% CO gas mixture, the above value of 23.6 and the copolymerization rate decrease with increasing temperature to 200°C. The kinetic data indicate a temperature-dependent depropagation reaction. Infrared examination of copolymers indicates a polyketone structure containing —CH2—CH2— and —CO— units. The crystalline melting point increases rapidly from 111 to 242°C., as the CO concentration in the copolymer increases from 27 to 50%. Molecular weight of copolymer formed at 20°C. increased with increasing CO, indicating M̄n values 〉20,000. Increasing reaction temperature results in decreasing molecular weight. Onset of decomposition for a 50% CO copolymer was measured at ≈250°C.
    Additional Material: 16 Ill.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 0721-3115
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The appearance of a significant deuterium isotope effect during the combustion of the solid HMX compound verifies that the chemical reaction kinetics is a major contributor in determining the experimentally observed or global burn rate. Burn rate comparison of HMX and its deuterium labeled HMX-d8 analogue reveals a primary kinetic deuterium isotope effect (1° KDIE) at 500 psig (3.55 MPa) and l000 psig (6.99 MPa) pressures and selectively identifies covalent carbon-hydrogen bond rupture as the mechanistic step which ultimately controls the HMX bum rate under the static combustion conditions of this experiment. The 1° KDIE value further suggests the rate-limiting C—H bond rupture occurs during the solid state HMX decomposition/deflagration portion of the overall combustion event and is supported by other independently published studies. A possible anomalous KDIE result at 1500 psig (10.4 MPa) is addressed. This condensed phase KDIE approach illustrates a direct link between lower temperature/pressure thermal decomposition and deflagration processes and their potential applicability to the combustion regime. Most importantly, a new general method is demonstrated for mechanistic combustion investigations which selectively permits an in-situ identification of the compound's burn rate-controlling step.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 0449-2986
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
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