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排序方式: 共有1747条查询结果,搜索用时 21 毫秒
61.
Abhinav Sharma Yashodhan Patil Ravi Krishnaiah PhD B. Ashok PhD Akhil Garg PhD Liang Gao PhD 《亚洲传热研究》2020,49(8):4626-4656
Lithium-ion cells are preferred in the electrical powertrain due to high-power density, compactness, and modularity. In real driving conditions, the cells undergo discharge rates as high as 4 C resulting in high heat generation affecting the performance. To obtain the maximum performance the pack construction and thermal management of cells are crucial parameters. In our work, air-cooled technique with diverse air inlet and staggered scheme with a two-channel partition approach for thermal management of the cylindrical lithium-ion cells are studied in computational fluid dynamics. The simulation model is validated with experimental results. The obtained results demonstrate that the cells in the dual-directional air inlet arrangement had low maximum temperature difference among and within the cells and required least fan work. This arrangement required least fan work to generate optimal air inlet velocity of 2 m/s for 1, 2, and 3 C and 4 m/s for 4 C discharge rates. There is a reduction of 50% and 33% fan work for 3 and 4 C discharge rates, which are the majority operating points. Also, it shows that the temperature uniformity within the cells has improved. The results of this study can used to optimize parameters for designing an enhanced thermal management system. 相似文献
62.
63.
Neural Computing and Applications - Heart diseases are of notable public health disquiet worldwide. Heart patients are growing speedily owing to deficient health awareness and bad consumption... 相似文献
64.
Ashok Kumar Dasmahapatra 《Journal of Polymer Research》2016,23(3):56
Blending of two or more pure polymers is an effective way to produce composites with tunable properties. In this paper, we report dynamic Monte Carlo simulation results on the crystallization of crystalline/crystalline (A/B) symmetric binary polymer blend, wherein the melting temperature of A-polymer is higher than B-polymer. We study the effect of segregation strength (arises from the immiscibility between A- and B-polymers) on crystallization and morphological development. Crystallization of A-polymer precedes the crystallization of B-polymer upon cooling from a homogeneous melt. Simulation results reveal that the morphological development is controlled by the interplay between crystallization driving force (viz., attractive interaction) and de-mixing energy (viz., repulsive interaction between two polymers). With increasing segregation strength, the interface becomes more rigid and restricts the development of crystalline structures. Mean square radius of gyration shows a decreasing trend with increasing segregation strength, reflecting the increased repulsive interaction between A- and B-polymers. As a consequence, a large number of smaller size crystals form with lesser crystallinity. Isothermal crystallization reveals that the transition pathways strongly depend on segregation strength. We also observe a path-dependent crystallization behavior in isothermal crystallization: two-step (sequential) isothermal crystallization yields superior crystalline structure in both A- and B-polymers than one-step (coincident) crystallization. 相似文献
65.
Raqibul Mostafa Ramesh C. Pallat Uwe Ringel Ashok A. Tikku Jeffrey H. Reed 《ETRI Journal》2012,34(3):319-329
Closed‐loop transmit diversity is considered an important technique for improving the link budget in the third generation and future wireless communication standards. This paper proposes several transmit diversity algorithms suitable for small wireless terminals and presents performance assessment in terms of average signal‐to‐noise ratio (SNR) and outage improvement, convergence, and complexity of operations. The algorithms presented herein are verified using data from measured indoor channels with variable antenna spacing and the results explained using measured radiation patterns for a two‐element array. It is shown that for a two‐element array, the best among the proposed techniques provides SNR improvement of about 3 dB in a tightly spaced array (inter‐element spacing of 0.1 wavelength at 2 GHz) typical of small wireless devices. Additionally, these techniques are shown to perform significantly better than a single antenna device in an indoor channel considering realistic values of latency and propagation errors. 相似文献
66.
S.L. Ashok Kumar M. Saravana Kumar R.P. John P. Thomas Muthiah A. Sreekanth 《Materials science & engineering. C, Materials for biological applications》2013,33(5):2519-2525
1,5-Bis (2-hydroxyacetophenone)thiocarbohydrazone (H4L) has been synthesized and characterized by means of spectroscopic and single crystal X-ray diffraction methods. Interactions of the H4L with a variety of anions were investigated using a combination of UV–visible and fluorescence spectroscopic methods in a biological competing solvent DMSO. The H4L has a high degree of selectivity for fluoride over other anions. 1H NMR titration experiments indicate that a deprotonation process is involved in the chemo sensing process. 相似文献
67.
N. G. Shiva Prasad G. V. Ashok H. M. Mahesh 《The International journal of environmental studies》2013,70(1):83-92
Potable waters from various locations of the Bangalore environment were investigated for their 222Rn concentrations by the emanometry method. About 94 groundwater (borewell) samples were analysed for 222Rn concentrations and found to vary in the range 5.3–283.4 Bq L?1 with a mean value of 87 Bq L?1. Frequency distribution showed the 222Rn concentration in a large number of samples in the range of 0–50 Bq L?1. From the measured concentrations, the effective doses (lung and stomach) for the population of the region were estimated. The effective dose was found to vary from 42.6 to 2280.2 µSv y?1 with a mean value 702.5 µSv y?1. The effect of boiling of water showed a drastic reduction in the 222Rn concentration. The results of the present investigation are systematically analysed, compared with the literature values and discussed. 相似文献
68.
The effect of liquid and gas velocities, solid concentrations, and operating pressure has been studied experimentally in a 15 cm diameter air-water-glass beads bubble column. The superficial gas and liquid velocities varied from 1.0 to 40.00 cm/s and 0 to 16.04 cm/s, respectively, while the solid loading varied from 1 to 9%. The gas holdup in the column was reduced sharply as we switched from batch to co-current mode of operation. At low gas velocity, the effect of liquid velocity was insignificant; while at high gas velocity, increasing liquid velocity decreased the gas holdup. Drift flux approach was applied to quantify the combined effect of liquid and gas velocities over gas holdup. For co-current three phase flows, the gas holdup decreased with increase in solid loading for all pressures. But for batch operations, when solid loading was 5% or more, settling started leading to higher gas holdup. Increasing pressure from atmospheric conditions increased the gas holdup significantly, flattening asymptotically. 相似文献
69.
Bansi L Raina Shri G Agarwal Ashok K Bhatia Govind S Gaur 《Journal of the science of food and agriculture》1996,71(1):27-32
Significant variations were observed in the concentration of pigments (10·0–17·0%, moisture-free basis) and flavour components during different post-harvest processing conditions of saffron (stigmas ex Crocus sativus L). The crocin pigments concentration was highest (15–17%) in the saffron samples dried between 35°C and 50°C either in a solar dryer or in an oven dryer and this also resulted in considerable reduction of normal drying time. Under these conditions the main flavouring component, safranal, was at its peak value of 60% in the oil in almost all the samples except the vacuum oven dried samples which interestingly contained 4-β-hydroxysafranal in major amounts. Studies indicated that 4-β-hydroxysafranal may be an intermediate in the formation of safranal. It was observed that prolonged storage affected the pigments and flavour concentration to a great extent, but proper packaging and storage with 5% moisture in the saffron reduced the deterioration, thereby increasing the shelflife of the product. 相似文献
70.
Ashok Pandey 《Starch - St?rke》1992,44(2):75-77
A laboratory process was established for the production of glucoamylase (amyloglucosidase) enzyme by Aspergillus niger (RRL isolate), using wheat bran of mixed particle size as main carbon source in solid cultures. The experimental studies were carried out in 500 ml conical flasks and subsequently in tray fermenters in static conditions. Experiments were conducted to monitor the impact of initial moisture content of the substrate as well as the steam cooking of the substrate on different atmospheric pressure on the productivity of the enzyme. An initial moisture level of 50–55% was found optimum for glucoamylase production when fermentation was carried out for 96h. Cooking of substrate at 1056 kg/cm2 under steam for 30 min gave most desirable qualities in substrate. 相似文献