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71.
A. Bhogal S. D. Young R. Ralph Sylvester Bradley J. Craigon 《Nutrient Cycling in Agroecosystems》1995,44(1):27-36
In 1977, a field trial was set up at Ropsley (UK) to study the effects of 8 nitrogen and 2 phosphate and potassium application rates on the response of crops grown in rotation and on the soil nutrient balance. An application of 87.3 and 166.0 kg ha–1 P and K fertilizer did not significantly increase the yield or nutrient offtake of winter wheat in comparison to 21.8 and 41.5 kg ha–1 P and K fertilizer. However, a build-up in available soil P and K reserves was observed.The high P and K application rate was terminated in 1981 and a progressive net fixation of P into non-available forms was subsequently observed. High available soil P resulted in greater rates of fixation but high N application rates effectively reduced the rate of fixation by imposing a high plant uptake demand. This paper describes simulation models of the soil phosphate dynamics observed under rotational cropping over a period of 7 years. 相似文献
72.
Daniel Povey Lukáš Burget Mohit Agarwal Pinar Akyazi Feng Kai Arnab Ghoshal Ondřej Glembek Nagendra Goel Martin Karafiát Ariya Rastrow Richard C. Rose Petr Schwarz Samuel Thomas 《Computer Speech and Language》2011,25(2):404-439
We describe a new approach to speech recognition, in which all Hidden Markov Model (HMM) states share the same Gaussian Mixture Model (GMM) structure with the same number of Gaussians in each state. The model is defined by vectors associated with each state with a dimension of, say, 50, together with a global mapping from this vector space to the space of parameters of the GMM. This model appears to give better results than a conventional model, and the extra structure offers many new opportunities for modeling innovations while maintaining compatibility with most standard techniques. 相似文献
73.
This paper examines the recently introduced charge-based capacitance measurement (CBCM) technique through use of a three-dimensional (3-D) interconnect simulator. This method can be used in conjunction with simulation at early process development stages to provide designers with accurate parasitic interconnect capacitances. Metal to substrate, interwire, and interlayer capacitances are each discussed and overall close agreement is found between CBCM and 3-D simulation. Full process interconnect characterization is one possible application of this new compact, high-resolution test structure 相似文献
74.
Quality changes in chicken nuggets fried in oils with different degrees of hydrogenatation 总被引:2,自引:0,他引:2
Quality changes in chicken nuggets fried in different mixtures of hydrogenated and non-hydrogenated canola oils were studied. Colour, texture, oil and moisture contents of the chicken nugget samples fried at 190 °C for 30, 60, 90, 120, 180, 240 and 300 s were investigated. The proportions of hydrogenated to non-hydrogenated frying oils used in the study were 0%, 20%, 40%, 60%, 80% and 100%.Results indicate that increase in frying time resulted in decreased product lightness (L*) whereas redness (a*) and yellowness (b*) increased. The maximum load to puncture increased with increasing frying time. In addition, oil content increased slowly with frying time, and moisture content decreased as expected. Both frying times and oil types have significant effects on the quality parameters investigated. First-order kinetic equation was used to describe colour changes as well as oil and moisture contents of the samples. Oil and moisture contents had negative correlation relationship. With increasing degree of oil hydrogenation, the surface colour of the fried chicken nuggets samples were lighter, texture increased, oil and moisture contents decreased. 相似文献
75.
Sylvester N Onyeneho Navam S Hettiarachchy 《Journal of the science of food and agriculture》1993,62(4):345-350
The effects of freeze-dried extracts from the peels of six potato varieties as antioxidants in pure soy oil were investigated using the active oxygen method (AOM) procedure, carotene bleaching and linoleic acid oxidation experiments on thin-layer chromatography (TLC) plates. At 9 h under AOM conditions, 20 g soy oil treated with 0.05 g of these extracts attained lower peroxide values (PV, 22.0-28.0 meq kg?1) than the control oil sample (PV, 109.0 meq kg?1) indicating very strong antioxidant activities. Oils treated with the same amount of tertiary butylhydroquinone, butylated hydroxyauisol-butylated hydroxytoluene mixture and rosemary extract attained PV of 10, 19.0 and 16.0 meq kg?1, respectively. Results of the carotene bleaching and linoleic acid oxidation experiments on TLC plates indicated that the antioxidant activities of these extracts were due to the presence of phenolic acids. Among the phenolic acids separated and identified by both high-performance liquid chromatography and TLC, chlorogenic, proto-catechuic and caffeic acids were predominant and appeared to be mainly responsible for the strong antioxidant activities of the extracts. Peels from the red potatoes contained more polyphenols than those from the brown-skinned varieties, but their oil contents were similar. 相似文献
76.
ABSTRACTTraumatic brain injury (TBI) due to blast exposure or head impacts in accidents or contact sports is one of the most critical and poorly understood areas of research in the 21st century. To date, the unavailability of human brain tissues (grey and white matter especially) due to ethical and biosafety issues has not allowed for much experimental research into the study of the mechanics of brain tissues under impact or dynamic loading. In the current work, for the first time, biofidelic brain tissue surrogates have been developed using a low cost, castable (to any shape or size), two-part silicone-based material system to precisely mimic the nonlinear mechanical properties of both the white and the grey matter. The fabrication methodology involves the iterative mixing of the two parts of silicone at certain mix ratios (by weight) to generate a biomechanical behavior similar to the white and the grey matter tissues, respectively, at two different strain rates (low and high). The nonlinear behavior of these novel brain tissue surrogates have been characterized using five hyperelastic material models. These brain tissue simulant materials would be indispensable not only for the study of TBI, but also to allow doctors to practice brain surgeries (for training purposes) in a clinical setting. Additionally, crucial brain tissue modifications in Alzheimer's disease and dementia can be studied in the future with such accessible biofidelic brain tissue surrogate materials. 相似文献
77.
An indirect method of estimation of size distribution of nanoparticles in a nanocomposite is proposed in this paper. The present approach exploits DC electrical current–voltage characteristics (CVC) of ZnO nanocomposite specimen in bio-polymer background. The nature of DC CVC is found to be oscillatory with respect to applied voltage. The nature of CVC is a consequence of Coulomb blockade (CB) phenomena of electrical conduction through a tiny nanoparticle. Considering the ZnO nanocomposites to be spherical, Coulomb-blockade model of quantum dot is applied here. The size distribution of particle is estimated from that model and compared with the results obtained from AFM and XRD analyses. The results from CVC are found to be consistent with these conventional microscopic results. 相似文献
78.
79.
Addressing fundamental challenges to designing high-performance ICs in nanometer-scale technologies, the authors advocate a flexible approach to limiting both dynamic and static power. They recommend global-signaling strategies to curb communication power requirements and thermal management techniques to ease the burden on packaging 相似文献
80.
Agarwal K. Rao R. Sylvester D. Brown R. 《Very Large Scale Integration (VLSI) Systems, IEEE Transactions on》2007,15(6):613-623
Parametric yield loss has become a serious concern in nanometer technologies. In this paper, we propose a methodology to estimate and optimize the parametric yield of a design in the presence of process variations. We discuss the impact of leakage on parametric yield given that leakage causes the parametric yield window to shrink by imposing a two-sided constraint in conjunction with performance targets on the yield window. We present a mathematical framework for yield estimation under process variation for a given power and frequency constraints. The model is validated against Monte Carlo SPICE simulations in a 90-nm CMOS process and is shown to have a typical error of less than 5%. We then demonstrate the importance of optimal supply and threshold voltage selection for yield maximization. Our results show that parametric yield is highly sensitive to supply voltage with only a 5% change in the supply voltage potentially leading to nearly 15% yield degradation. We also investigate the sensitivity of parametric yield to required frequency and power constraints. Finally, we apply the proposed framework to the problem of maximizing the shipping frequency in the presence of given yield and power constraints. 相似文献