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131.
In present communication, an attempt has been made to study the heat and mass transfer for crops namely wheat and gram. The removal of moisture from the crop was determined under simulated conditions and it was used to develop heat and mass transfer relation using linear as well as multiple regression analysis. The observations were recorded for relative humidity, temperature of crop and air and for moisture evaporated. Experimental error in terms of per cent uncertainty was calculated for recorded data which is in the range of 20 - 30 per cent for forced convection and natural cooling, respectively. 相似文献
132.
We show nearly 8 dB of crosstalk reduction using ground planes between active device layers in three-dimensional (3-D) integrated circuits. Our experimental work utilizes two planes of MOS transistors with tungsten or polysilicon ground planes designed to attenuate crosstalk. Theoretical simulations, using an electromagnetic solver, and the experimental results are consistent with analytical results. The key result verified is that a ground plane, whose footprint shadows the device area, is sufficiently large for effective attenuation. The interdevice layer ground plane provides an effective means to achieve crosstalk reduction in 3-D mixed-signal/RF integration because of simple fabrication and high coupling isolation. 相似文献
133.
The loss of zero-voltage-switching (ZVS) of active switches has been a serious limitation of full-bridge (FBZVS) converters.
Many techniques have been proposed in the past to extend the range of ZVS operation over the wider and also the full range
of operation. However, in these techniques ZVS is achieved at the expense of additional conduction loss in active switches
and losses in the auxiliary components. In this paper, the analysis for the additional losses in various full-range FBZVS
DC-DC converters and their comparative evaluation is reported. Closed form expressions are derived for average value of device
currents and losses. The loss curves for various topologies are plotted and compared. The analytical results are found to
be consistent with the experimental efficiency tests performed on 500 W, 100 kHz prototype. It is concluded that a recently
proposed new topology has the least penalty of additional losses. 相似文献
134.
B Das K Ramakrishna G D Verma R S Tiwari O N Srivastava 《Bulletin of Materials Science》1991,14(3):585-592
The second generation of high temperature superconductors typified by Bi2Sr2Ca
n−1Cu
n
O2n+4 and Tl2Ba2Ca
n−1Cu
n
O2n+4 exhibits curious structural properties which have direct relevance to the superconducting behaviour particularly transition
temperature (T
c
). The present paper reports on investigations of structural properties at microlevel in Bi-bearing HTCS. We have found curious
structural characteristics which manifests itself in the form of transformation froma
p
×a
p
×c to (2)1/2
a
p
×(2)1/2
a
p
×c through the loss of calcium atoms and the formation of five-fold modulated phase alongb through the loss of Ca and Sr atoms. We have also found the evidence of high periodicities (n=4) Bi2Sr2Ca3Cu4O12. The microstructural characteristics of HTCS showing the higherT
c
(R=0) ∼ 120 K exhibits unusual characteristics. 相似文献
135.
Bioactive peptides and carbohydrates are sourced from a myriad of plant, animal and insects and have huge potential for use as food ingredients and pharmaceuticals. However, downstream processing bottlenecks hinder the potential use of these natural bioactive compounds and add cost to production processes. This review discusses the health benefits and bioactivities associated with peptides and carbohydrates of natural origin and downstream processing methodologies and novel processes which may be used to overcome these. 相似文献
136.
Pranab K. Shyam Yu Kwon Kim Chan Lee Hye‐Young Jang 《Advanced Synthesis \u0026amp; Catalysis》2016,358(1):56-61
Copper‐catalyzed aerobic coupling of thiols and alcohols affords sulfinates and thiosulfonates. These products are assumed to form via sulfinyl radicals which are not commonly found in oxidative coupling reactions of thiols. A reaction mechanism involving sulfinyl radicals is proposed, and mass and electron paramagnetic resonance (EPR) experimental results are provided.
137.
Yiqian Zhu Aijun Wang Wenqian Shen Shyam Patel Rong Zhang William L. Young Song Li 《Advanced functional materials》2010,20(9):1433-1440
The difficulty in spinal cord regeneration is related to the inhibitory factors for axon growth and the lack of appropriate axon guidance in the lesion region. Here scaffolds are developed with aligned nanofibers for nerve guidance and drug delivery in the spinal cord. Blended polymers including poly(L ‐lactic acid) (PLLA) and poly(lactide‐co‐glycolide) (PLGA) are used to electrospin nanofibrous scaffolds with a two‐layer structure: aligned nanofibers in the inner layer and random nanofibers in the outer layer. Rolipram, a small molecule that can enhance cAMP (cyclic adenosine monophosphate) activity in neurons and suppress inflammatory responses, is immobilized onto nanofibers. To test the therapeutic effects of nanofibrous scaffolds, the nanofibrous scaffolds loaded with rolipram are used to bridge the hemisection lesion in 8‐week old athymic rats. The scaffolds with rolipram increase axon growth through the scaffolds and in the lesion, promote angiogenesis through the scaffold, and decrease the population of astrocytes and chondroitin sulfate proteoglycans in the lesion. Locomotor scale rating analysis shows that the scaffolds with rolipram significantly improved hindlimb function after 3 weeks. This study demonstrates that nanofibrous scaffolds offer a valuable platform for drug delivery for spinal cord regeneration. 相似文献
138.
Ashutosh Tiwari Mani Prabaharan Ravi R. Pandey Songjun Li 《Journal of Inorganic and Organometallic Polymers and Materials》2010,20(2):380-386
A hydrated tungsten oxide (WO3·nH2O)-embedded aniline–formaldehyde condensate (AFC/WO3·nH2O) nanocomposite thin film was prepared on an indium tin oxide (ITO)-coated glass surface via vacuum-deposition technique.
The resulting AFC/WO3·nH2O/ITO thin film was characterized using ultraviolet–visible spectroscopy (UV–Vis), Fourier transform infrared spectroscopy
(FTIR), X-ray diffractometry (XRD), and electron microscopy (SEM). The composite thin film exhibited a crystalline surface
morphology containing nanocrystals of WO3·nH2O with a diameter ranging from 15 to 20 nm. The AFC/WO3·nH2O/ITO film allowed for the low potential detection of NO2 gas at a concentration range from 0 to 9000 ppm. The NO2 gas sensing characteristics were studied by measuring the change in the current with respect to concentration and time. The
current of the AFC/WO3·nH2O/ITO film linearly increased with an increase in concentration of NO2 gas with a response of ~20 s. 相似文献
139.
Stability of anthocyanins in frozen and freeze-dried raspberries during long-term storage: in relation to glass transition 总被引:2,自引:0,他引:2
Abstract: Anthocyanins, natural plant pigments in the flavonoid group, are responsible for the red color and some of the nutraceutical benefits of raspberries. This study explores anthocyanin degradation in frozen and freeze‐dried raspberries during storage in relation to glass transition temperatures. Frozen raspberries were stored at ?80, ?35, and ?20 °C, while freeze‐dried raspberries were stored at selected water activity (aw) values ranging from 0.05 to 0.75 at room temperature (23 °C) for more than a year. The characteristic glass transition temperatures (T′g) of raspberries with high water content and glass transition temperature (Tg) of raspberries with small water content were determined using a differential scanning calorimeter. The pH differential method was used to determine the quantity of anthocyanins in frozen and freeze‐dried raspberries at selected time intervals. The total anthocyanins in raspberries fluctuated during 378 d of storage at ?20 and ?35, and ?80 °C. Anthocyanin degradation in freeze‐dried raspberries ranged from 27% to 32% and 78% to 89% at aw values of 0.05 to 0.07 and 0.11 to 0.43, respectively, after 1 y. Anthocyanins were not detectable in freeze‐dried raspberries stored at aw values of 0.53 to 0.75 after 270 d. First order and Weibull equations were used to fit the anthocyanin degradation in freeze‐dried raspberries. The 1st‐order rate constant (k) of anthocyanin degradation ranged from 0.003 to 0.023 days?1 at the selected water activities. Significant anthocyanin degradation occurred in both the glassy and rubbery states of freeze‐dried raspberries during long‐term storage. However, the rate of anthocyanin degradation in freeze‐dried raspberries stored in the glassy state was significantly smaller than the rate of anthocyanin degradation in the rubbery state. 相似文献
140.
Brajesh Tiwari Babu Baijnath Prasad Rajveer Jha Dharmendra Kumar Singh V. P. S. Awana 《Journal of Superconductivity and Novel Magnetism》2014,27(10):2181-2183
In the present short letter, we report on the low dimensional 4d and 5d transition metals-chalcogenide based compounds i.e., Ta2PdxS6, showing semiconducting to superconducting transition at around 4K with their upper critical fields outside the Pauli paramagnetic limit. It seems couple of different superconducting phases do exist in these new set of compounds. Our short letter in this regards is thought provoking, asking to explore various unearthed possible new superconducting phases in (Nb/Ta)2Pdx(S/Se/Te)y systems. 相似文献