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81.
82.
M. Sajid N. Ali T. Hayat 《Communications in Nonlinear Science & Numerical Simulation》2009,14(2):451-461
The present paper contains the exact solutions for thin film flows of a micropolar fluid. Thin films are considered for three different geometries namely: (i) flow down an inclined plane, (ii) flow on a moving belt and (iii) flow down a vertical cylinder. The exact solution is obtained for the velocity and micro-rotation in first two cases for both weak and strong concentrations of the microelements. However, the exact expression for the micro-rotation is obtained for the third case and a numerical solution is presented for the velocity. The micro-rotation and velocity fields are sketched and discussed for different values of the material parameters. It is observed that the rotation of the microelements at the boundary increases the velocity when compared with the case when there is no rotation at the boundary. 相似文献
83.
84.
Mohsin Ali Chaudry Christian Woitzik Christian Weißenfels Alexander Düster Peter Wriggers 《PAMM》2016,16(1):311-312
In this contribution, a novel design strategy is investigated for improving the crashworthiness of double-hull vessels, which involves usage of granular materials. For numerical simulation, a framework based on coupling of the Discrete Element and the Finite Element Method is used to study load bearing capacity of granular materials during uniaxial compression. In addition, the effect of Young's modulus of particles is also investigated with respect to the load transferability. (© 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
85.
Monireh Heshmati Gonbari Ali Ramazani Ali Souldozi 《Phosphorus, sulfur, and silicon and the related elements》2013,188(2):309-314
N, N′ -diphenylthiourea reacts with dialkyl acetylenedicarboxylates in acetone to form 1:1 adducts, which undergo a cyclization reaction to produce alkyl (Z)-2-[4-oxo-3-phenyl-2-(phenylimino)-1,3-thiazolan-5-yliden]acetates in fairly good yields. NMR spectra indicated that the reaction is completely stereoselective. 相似文献
86.
Ali Deeb 《Phosphorus, sulfur, and silicon and the related elements》2013,188(10):637-650
AbstractThis review describes the synthesis and reactions of 5-aminothieno[2,3-c]pyridazine-6-carbonitriles as a building blocks for the synthesis of polyfunctionalized heterocyclic compounds. The antimicrobial activity of some compounds are discussed. 相似文献
87.
Mahdi Tohidian Seyed Reza Ghaffarian Seyed Emadodin Shakeri Erfan Dashtimoghadam Mohammad Mahdi Hasani-Sadrabadi 《Journal of Solid State Electrochemistry》2013,17(8):2123-2137
Nanocomposite membranes based on polyelectrolyte complex (PEC) of chitosan/phosphotungstic acid (PWA) and different types of montmorillonite (MMT) were prepared as alternative membranes to Nafion for direct methanol fuel cell (DMFC) applications. Fourier transform infrared spectroscopy (FTIR) revealed an electrostatically fixed PWA within the PEC membranes, which avoids a decrease in proton conductivity at practical condition. Various amounts of pristine as well as organically modified MMT (OMMT) (MMT: Cloisite Na, OMMT: Cloisite 15A, and Cloisite 30B) were introduced to the PEC membranes to decrease in methanol permeability and, thus, enhance efficiency and power density of the cells. X-ray diffraction patterns of the nanocomposite membranes proved that MMT (or OMMT) layers were exfoliated in the membranes at loading weights of lower than 3 wt.%. Moreover, the proton conductivity and the methanol permeability as well as the water uptake behavior of the manufactured nanocomposite membranes were studied. According to the selectivity parameter, ratio of proton conductivity to methanol permeability, the PEC/2 wt.% MMT 30B was identified as the optimum composition. The DMFC performance tests were carried out at 70 °C and 5 M methanol feed and the optimum membrane showed higher maximum power density as well as acceptable durability compared to Nafion 117. The obtained results indicated that owing to the relatively high selectivity and power density, the optimum nanocomposite membrane could be considered as a promising polyelectrolyte membrane (PEM) for DMFC applications. 相似文献
88.
Hamid Hadi-Alijanvand Ali A. Moosavi-Movahedi Bahram Goliaei 《Journal of the Iranian Chemical Society》2013,10(5):907-914
Prolyl hydroxylase domain 2 containing protein (PHD2) is a central protein in regulation of cellular response to hypoxia. This protein controls the responses of cell to oxygen level via the regulation of hypoxia inducible factor (HIF) stability. HIF induces the expression of many genes, especially ones orchestrate angiogenesis. There are some reports that mentioned in some tumor types the level of HIF is high in spite of the presence of wild-type PHD2 and normoxic environment. Therefore, the possibility of PHD2 misfolding in some cancer cells arises. Studying such important protein unfolding pathway is insightful for possible therapeutic approaches. In this study, the unfolding pathway of PHD2 illustrates utilizing molecular dynamics simulation of protein thermal denaturation. Based on current study results, we represent the possible mechanisms of PHD2 unfolding in detail. The possible intermediates of PHD2 thermal unfolding are characterized, and the most venomous state of its unfolding pathway is introduced. 相似文献
89.
Reza Ghiasi Hoda Pasdar 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2013,87(6):973-978
The electronic structure and properties of the platinabenzene and para substituted platinabenzenes have been investigated using the hybrid density functional mpw1pw91 theory. The substituent effect in structure parameters, frontier orbital energies, aromaticity indexes, and hyperpolarizability has been studied. The calculations show that, in all molecules HOMO → LUMO transition makes the major contribution in the most intense electronic transition. 相似文献
90.
A novel chiral ionic liquid (CIL) based on nicotinium salt has been synthesized and used as an efficient asymmetric chiral catalyst for reduction of acetophenone derivatives with NaBH4 in methanol at room temperature. The optically active alcohols were obtained in low to moderate enantiomeric excess in a short reaction time. 相似文献