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251.
252.
B K Roul A K Pradhan V V Rao P Bhattacharya P Pramanic V R Kalvey D N Bose K L Chopra 《Bulletin of Materials Science》1991,14(3):713-718
Studies of the effect of high power laser (Q-switched Ruby laser, 694 nm, 30 ns) irradiation on the critical current density
(J
c
) and magnetic hysteresis at 77K and temperature variation of microwave induced d.c. voltage on SmBa2Cu3O
x
ceramic samples have been performed. Irradiation did not substantially changeT
c
but caused a strong increase inJ
c
and magnetic hysteresis at 77K. The microwave-induced d.c. voltage at 77K showed appreciable decrease after irradiation.
SEM studies showed grain growth due to sintering which improves the interconnectivity among the superconducting grains. These
are attributed to physical densification and consequent reduction in the number of weak links. The increase of magnetic hysteresis
after laser irradiation is presumably connected with the creation of defects which act as pinning centres. Thermal modelling
suggests that on irradiation the surface melts up to a depth of 1μ and laser-induced evaporation occurs at energy density of 2·5 J/cm2. 相似文献
253.
J Katz KP West SC LeClerq MD Thapa SK Khatry SR Shresta EK Pradhan RP Pohkrel 《Canadian Metallurgical Quarterly》1998,44(4):225-229
Traumatic diaphragmatic hernia is rare, but is of utmost importance due to its high morbidity and mortality. It is markedly important in patients with blunt abdominal trauma, and diagnosis is difficult because of the numerous associated injuries. A patient with few symptoms of chronic traumatic diaphragmatic hernia is described, who underwent surgery due to a gastric volvulus. Laparoscopic surgery permits repair of these injuries through an abdominal approach, avoiding a thoracic incision or selective intubation. 相似文献
254.
This paper describes a novel application of singular value decomposition (SVD) of subsets of the phase-space trajectory for
calculation of the attractor dimension of a small data set. A certain number of local centres (M) are chosen randomly on the attractor and an adequate number of nearest neighbours (q=50) are ordered around each centre. The local intrinsic dimension of a local centre is determined by the number of significant
singular values and the attractor dimension (D
2) by the average of the local intrinsic dimensions of the local centres. The SVD method has been evaluated for model data
and EEG. The results indicate that the SVD method is a reliable approach for estimation of attractor dimension at moderate
signal to noise ratios. The paper emphasises the importance of SVD approach to EEG analysis. 相似文献
255.
Chakradhar S.T. Banerjee S. Roy R.K. Pradhan D.K. 《Very Large Scale Integration (VLSI) Systems, IEEE Transactions on》1996,4(2):254-263
We show that existing synthesis techniques may produce asynchronous circuits that are not initializable by gate level analysis tools even when the design is functionally initializable. Due to the absence of any initialization sequence, a fault simulator or test generator that assumes an unknown starting state will be completely ineffective for these circuits. In this paper, we show that proper consideration of initializability during the asynchronous circuit synthesis procedure can guarantee initializable implementations. We show that the assignment of don't cares during the synthesis procedure affects the initializability of the final implementation. We present a novel implicit enumeration procedure that selectively assigns don't cares to obtain an initializable implementation. Initialization sequences are obtained as a by-product of our synthesis procedure 相似文献
256.
Epoxidation of karanja (Pongamia glabra) oil by H2O2 总被引:1,自引:0,他引:1
Vaibhav V. Goud Narayan C. Pradhan Anand V. Patwardhan 《Journal of the American Oil Chemists' Society》2006,83(7):635-640
Epoxidation of karanja oil (KO), a nondrying vegetable oil, was carried out with peroxyacetic acid that was generated in situ from aqueous hydrogen peroxide and glacial acetic acid. KO contained 61.65% oleic acid and 18.52% linoleic acid, respectively,
and had an iodine value of 89 g/100 g. Unsaturated bonds in the oil were converted to oxirane by epoxidation. Almost complete
epoxidation of ethylenic unsaturation was achieved. For example, the iodine value of the oil could be reduced from 89 to 19
by epoxidation at 30°C. The effects of temperature, hydrogen peroxide-to-ethylenic unsaturation ratio, acetic acid-to-ethylenic
unsaturation ratio, and stirring speed on the epoxidation rate and on oxirane ring stability were studied. The rate constant
and activation energy for epoxidation of KO were 10−6 L·mol−1·s−1 and 14.9 kcal·mol−1, respectively. Enthalpy, entropy, and free energy of activation were 14.2 kcal·mol−1, −51.2 cal·mol−1·K−1, and 31.1 kcal·mol−1, respectively. The present study revealed that epoxides can be developed from locally available natural renewable resources
such as KO. 相似文献
257.
258.
259.
The cross-resistance characteristics of a lindane-resistant strain of Tribolium castaneum (Herbst) selected under pressure with lindane in the laboratory were studied. The strain was >86 times resistant to lindane as compared to the susceptible, and also showed resistance to eight other insecticides viz. dieldrin (>291 ×), heptachlor (>232 ×), endrin (>165 ×), aldrin (>147 ×), chlordane (>34 ×), endosulfan (>8 ×), toxaphene (>9 ×) and carbaryl (>12 ×). No cross-resistance was indicated to parathion (2·0 ×), diazinon (1·1 ×), malathion (1·0 ×), p,p′DDT (0·7 ×) and pyrethrins (1·5 ×). 相似文献
260.
The use of the KMnO4—oxalic acid redox system to initiate graft copolymerization of methyl methacrylate (MMA) onto poly(ethylene terephthalate) (PET) fiber has been investigated. The rate of grafting was determined by varying the concentrations of monomer, KMnO4, oxalic acid, acidity of the medium, and temperature. The graft yield increases steadily with increasing KMnO4 concentration. The graft yield is also influenced with concentration. The graft yield is also influenced with temperature. The effect of certain solvents on the rate of grafting has been investigated, and a suitable reaction mechanism has been proposed. 相似文献