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81.
M. Sreenivasulu K. Arun KumarK. Sateesh Reddy K. Siva KumarP. Rajender Kumar K.B. ChandrasekharManojit Pal 《Tetrahedron letters》2011,52(6):727-732
A rapid, economic, and high yielding methodology has been developed for hydroacylation/reduction of activated ketones by using 1,3-bis(2,4,6-trimethylphenyl)imidazolium chloride as a catalyst in combination with triethylamine. The reaction proceeded at an ambient temperature via generating N-heterocyclic carbene in situ that interacted with the (hetero)aryl aldehyde employed. While the reduction of ketones takes place in MeOH, the hydroacylation process was found to be effective in THF for both electron rich and deficient aldehydes. 相似文献
82.
Magnetic nanocomposite material composed of poly vinyl alcohol encapsulated Ni0.2Ca0.8Gd0.08Fe1.92O4 was synthesized by a two step chemical method including sol-gel combustion and solvent casting technique. The obtained samples were characterized by powder X-ray diffraction; transmission electron microscopy and Fourier transform infrared spectroscopy. The results of spectroanalysis pointed towards the existence of a considerably feasible interaction between the polymer chain and the ferrite particles. The dc magnetization measurements divulged that both pristine and the nanocomposite samples under applied magnetic field exhibit no hysteretic behavior at room temperature, symptomatic of the superparamagnetic behavior. The departure of field cooled and zero field cooled curves in the moment-versus-temperature plot further confirmed the room temperature superparamagnetic behavior. The extrapolation of the slope of the curves to M=0 imparted the average value of Curie temperature at ∼323 K (50 °C) for both the samples, suggestive of the efficacy of the material for finding application in self controlled hyperthermia. 相似文献
83.
84.
Arun K. Varshneya 《Journal of Non》1986,80(1-3):688-692
Shelyubskii wavelength scan technique to measure glass homogeneity is described. The Raman-Shelyubskii theory, which is based upon interference optics and which, hitherto, was believed to be the underlying mechanism, is discarded. A computer simulation of light scattering based on geometric optics principles fits the observed transmission vs wavelength curves very well. 相似文献
85.
DeSouza Arun H. G. Wilson David J. Tanner Robert D. 《Applied biochemistry and biotechnology》1990,24(1):565-578
Applied Biochemistry and Biotechnology - Extracellular proteins produced by yeast have been observed to stratify in the extracellular fluid of a batch bioreactor, thus creating a vertical... 相似文献
86.
V. Sankaranarayanan Arun D. Mahindrakar Ravi N. Banavar 《Communications in Nonlinear Science & Numerical Simulation》2008,13(10):2266-2278
We present a switched control law for stabilizing an underactuated underwater vehicle (UUV) moving in a horizontal plane in a neutrally buoyant condition. The control law consists of a sequential series of control actions, each of which achieves a certain objective, finally resulting in the system being moved to the origin. Finite-time controllers are employed at each stage to achieve the desired objective. Simulation results are presented to validate the control law. 相似文献
87.
This paper deals with a new solution technique for approximately solving certain variational problems in elasticity by using discrete optimization techniques that were originally used in information theory. This allows us to easily and approximately solve large deformation buckling problems for slender cantilever beams (including post-buckling behavior) as well as problems where the strain energy function is non-convex.The core idea is to quantize or discretize the variables describing the possible configurations of the body. This, when combined with the fact that the variational problem has an inherent Markov structure allows us to use computationally efficient search techniques based on dynamic programming (equivalent to finding the shortest path in a weighted directed graph) to find optimal solutions within the quantized state space. The results can be used in two ways: (1) directly as a fast approximate solution to the variational problem (2) As a means for finding very good (nearly minimum energy) initial configurations for application of conventional minimization techniques, which might otherwise fail because of a poor starting configurations which are far from the global minimum. We demonstrate both these uses in the paper. 相似文献
88.
89.
Kashinath Chatterjee 《Annals of the Institute of Statistical Mathematics》1990,42(4):783-803
This paper describes the construction of search designs which permit the estimation of the general mean and main-effects,
and allow the search for and estimation of one possibly unknown non-zero effect among the two-and three-factor interactions
in the general symmetric and asymmetric factorial set-up. 相似文献
90.
Arun S. Mujumdar 《Transport in Porous Media》2007,66(1-2):3-18
Over the past three decades there has been nearly exponential growth in drying R&D on a global scale. Although thermal drying
had always been the workhorse of almost all major industrial sectors, the need for and opportunities in basic as well as industrial
research became clear only after the energy crisis of the early 1970s. Although the price of oil did drop subsequently the
awareness of the significance of improving the drying operation to save energy, improve product quality as well as reduce
environmental effect remained and indeed has flourished over recent years. New drying technologies, better operational strategies
and control of industrial dryers, as well as improved and more reliable scale-up methodologies have contributed to better
cost-effectiveness and better quality dried products. Yet there is no universally or even widely applicable drying theory
on the horizon. Most mathematical models of drying remain product-equipment specific for a variety of reasons. In this paper,
we examine the role of innovation in drying in various industrial sectors, e.g. paper, wood, foods, agriculture, waste management,
etc. Progress made over the past three decades and the challenges ahead are outlined. Some areas in need of further research
are identified. Examples of intensification of innovation in dryer designs via mathematical modeling are discussed. Finally,
the need for closer interaction between academia and industry is stressed as the key to successful drying R&D in the coming
decade. 相似文献