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21.
William R. Chase Muraleedharan G. Nair Alan R. Putnam Saroj K. Mishra 《Journal of chemical ecology》1991,17(8):1575-1584
Acinetobacter calcoaceticus, a gram-negative bacterium isolated from field soil, was found to be responsible for the biotransformation of 2(3H)-benzoxazolinone (BOA) to 2,2-oxo-1,1-azobenzene (AZOB). Experiments were conducted to evaluate the transformation of BOA to AZOB by this microbe in sterile and nonsterile soil. Transformation studies with soils inoculated withA. calcoaceticus indicated that the production of AZOB increased linearly with the concentration of BOA in sterile soil and showed a quadratic trend in nonsterile soils. This also indicated that all soil types studied for the transformation experiments might containA. calcoaceticus capable of the conversion of benzoxazolinones. 相似文献
22.
Recognizing a subject given a set of biometrics is a fundamental pattern recognition problem. This paper builds novel statistical models for multibiometric systems using geometric and multinomial distributions. These models are generic as they are only based on the similarity scores produced by a recognition system. They predict the bounds on the range of indices within which a test subject is likely to be present in a sorted set of similarity scores. These bounds are then used in the multibiometric recognition system to predict a smaller subset of subjects from the database as probable candidates for a given test subject. Experimental results show that the proposed models enhance the recognition rate beyond the underlying matching algorithms for multiple face views, fingerprints, palm prints, irises and their combinations. 相似文献
23.
This experimental study evaluated the water absorption characteristics of pineapple leaf fiber (PALF)–polyester composites of different fiber content. The degree of water absorption was found to increase with fiber loading. The mechanism of diffusion was analyzed and the effect of fiber loading on the sorption kinetics was studied. The diffusion coefficient was calculated and found to increase with fiber content. Studies were also made to correlate water absorption with the cross‐sectional areas of the specimens. The effects of ageing on the tensile properties and dimensional stability of PALF polyester composites were studied under two different ageing conditions. Ageing studies showed a decrease in tensile strength of the composites. The composite specimens subjected to thermal ageing showed only a slight deterioration in strength. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 503–510, 2004 相似文献
24.
P.?N.?Mayamol T.?Samuel C.?Balachandran A.?Sundaresan C.?ArumughanEmail author 《Journal of the American Oil Chemists' Society》2004,81(4):407-413
Several pilot-scale trials reported in this paper, using palm stearin-rice bran oil (PS-RBO) blends, obviously did not contain
trans FA (TFA), whereas the commercial products were found to contain 18–27% TFA. The effects of processing conditions such as
rate of agitation, crystallization temperature, and composition of the blends on the crystal structure of shortenings were
studied. The products were evaluated for their physicochemical characteristics using DSC, X-ray diffraction (XRD), HPLC, and
FTIR techniques. The formulation containing 50% PS and 50% RBO showed melting and cooling characteristics similar to those
of hydrogenated commercial “vanaspati” samples. Analysis of the FA composition revealed that the formulated shortenings contained
15–19% C18∶2 PUFA. Tocopherol and tocotrienol contents of the experimental shortenings were in the range of 850–1000 ppm with oryzanol
content up to 0.6%. XRD studies demonstrated that the crystal form in the shortenings was predominantly the most stable β′
form, and there was less of the undesirable β form. 相似文献
25.
L. A. Ehrhart R. Balachandran A. Butkus L. A. Lewis A. Lazzarini Robertson 《Lipids》1971,6(12):895-900
Dogs were maintainedoon a control ration or on a semisynthetic diet, containing 5% cholesterol and 16% hydrogenated coconut
oil, known to induce hyperlipemia and arteriosclerosis. Circulating leukocytes isolated from dogs fed the coconut oil containing
diet were shown to incorporate 50% more radioactivity into lipids than control leukocytes when incubated with acetate-1-14C. This increase, expressed as dpm/mg of leukocyte DNA, was not specific for any particular lipid since the distribution of
radioactivity between neutral lipids and phospholipids, as well as among their subfractions, was the same regardless of the
diet fed. The labeling patterns observed suggest that leukocyte fatty acid synthesis from acetate occurs predominantly, and
perhaps exclusively, by the chain elongation pathway. 相似文献
26.
John S. Haggerty A. Lightfoot John E. Ritter Paul A. Gennari S. V. Nair 《Journal of the American Ceramic Society》1989,72(9):1675-1679
Reaction-bonded Si3 N4 (RBSN) made from high-purity Si powder is unusually resistant to degradation caused by exposures to air for up to 50 h at temperatures up to 1400°C. The weight gain during oxidation of this SiH4 -originating RBSN is approximately 10 times less than conventional RBSN. Contrary to normally observed strength degradations, room-temperature strengths of this high-purity, oxidized RBSN (avg = 435 MPa, max. = 668 MPa) remained at their unusually high, as-processed levels after 1000° and 1400°C oxidizing exposures. Fracture toughness values were unaffected by oxidation ( K IC = 2.3 to 2.4 MPa · m1/2 ). This superior oxidation resistance results from the high purity and the small diameter pore channels (0.01 to 0.06 μm) achieved in this SiH4 -originating RBSN. 相似文献
27.
V. Sekkar K. Narayanaswamy K. J. Scariah P. R. Nair K. S. Sastri How Ghee Ang 《应用聚合物科学杂志》2006,101(5):2986-2994
Hydroxyl‐terminated polybutadiene (HTPB)‐based allophanate–urethane networks were prepared by reacting HTPB with di‐isocyanates, such as toluene–di‐isocyanate (TDI), isophorone–di‐isocyanate (IPDI), and 4,4′‐di(socyanatocyclohexyl)methane (H12MDI) at stoichiometric ratios (r‐values) ranging from 1.0 to 1.5. The networks were characterized for mechanical and swell properties. The network parameters, such as “X,” which is the fraction of urethane groups involved in the allophanate formation, and effective chain length (Lx) were calculated from experimental crosslink density values determined from swell data, using α‐model equations developed by Marsh. Excellent linear correlations were obtained between mechanical properties and the calculated network parameters. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2986–2994, 2006 相似文献
28.
Cathodic disbonding and charge transport through paint films were studied as a function of polarization potential, temperature, dry-film thickness and cation type in the electrolyte. It was found that both the disbonding rate and the charge transport were linearly related to the polarization potential. The activation energy for the disbonding process and the charge transport were quite different. The disbonding rate was linearly related to the dry-film thickness and was dependent on the cation type in the electrolyte. This was not the case for the charge transport. The results indicate a rate controlling factor for the disbonding process involving transport of cations through the film where the film is already disbonded. A fundamental difference in the conductive properties of the paint film on either side of the disbonding front is also proposed. 相似文献
29.
30.
The effect of nonlinear signal absorption (NLSA) due to ground-state absorption and excited-state absorption in a transversely pumped high-power dye laser amplifier is theoretically examined with a one-dimensional steady-state model for a dye amplifier pumped by a copper vapor laser. A well-approximated analytical expression for the extraction efficiency is derived, from which the effect of NLSA in reducing the amplifier efficiency can be appreciated immediately and can also be interpreted in terms of certain characteristic lengths. The reduction in efficiency due to NLSA is found to be largely independent of the pump power, provided that the signal power is increased linearly with the pump power to continue to saturate the amplifier gain and suppress amplified spontaneous emission. 相似文献