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951.
The aim of this paper is to propose a new numerical model to simulate 2D vesicles interacting with a Newtonian fluid. The inextensible membrane is modeled by a chain of circular rigid particles, which are maintained in cohesion by using two different types of forces. First, a spring force is imposed between neighboring particles in the chain. Second, in order to model the bending of the membrane, each triplet of successive particles is submitted to an angular force. Numerical simulations of vesicles in shear flow have been run using FEM and the FreeFem++ software. Exploring different ratios of inner and outer viscosities, we recover the well‐known ‘tank‐treading’ and ‘tumbling’ motions predicted by a theory and experiments. Moreover, for the first time, 2D simulations of the ‘vacillating‐breathing’ regime without special ingredient such as thermal fluctuations are recovered. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
952.
Ismail Ajaj Jasmina Markovski Jelena Marković Maja Jovanović Miloš Milčić Fathi Assaleh Aleksandar Marinković 《Structural chemistry》2014,25(4):1257-1270
The tautomeric equilibria between 2-pyridone and 2-hydroxypyridine forms of methoxy, chloro, and nitro derivatives of 3-cyano-4-(2-, 3-, and 4-substituted phenyl)-6-phenyl-2(1H)-pyridones were evaluated from UV/Vis spectral data. Linear solvation energy relationships of Kamlet–Taft and Catalán-rationalized solvent have influence on tautomeric equilibria. Transmission of substituent effect was analyzed by the Hammett equation. Quantum chemical calculations were performed by density functional theory (B3LYP). The experimental data were interpreted with the aid of time-dependent density functional method. Electron density distribution was analyzed by Bader’s analysis. It was found that substituents of different electronic properties change the extent of conjugation, and affect intramolecular charge transfer character. Theoretical calculations and experimental results gave insight into the influence of the molecular conformation on the transmission of substituent effects, as well as on contribution of different solvent–solute interactions. 相似文献
953.
Surface roughness and color characteristics of wood treated with preservatives after accelerated weathering test 总被引:2,自引:0,他引:2
Ali Temiz Umit C. Yildiz Ismail Aydin Morten Eikenes Gry Alfredsen Gürsel olakoglu 《Applied Surface Science》2005,250(1-4):35-42
Wood samples treated with ammonium copper quat (ACQ 1900 and ACQ 2200), chromated copper arsenate (CCA), Tanalith E 3491 and Wolmanit CX-8 have been studied in accelerated weathering experiments. The weathering experiment was performed by cycles of 2 h UV-light irradiation followed by water spray for 18 min. The changes on the surface of the weathered samples were characterized by roughness and color measurements on the samples with 0, 200, 400 and 600 h of total weathering.
The objective of this study was to investigate the changes created by weathering on impregnated wood with several different wood preservatives. This study was performed on the accelerated weathering test cycle, using UV irradiation and water spray in order to simulate natural weathering.
Surface roughness and color measurement was used to investigate the changes after several intervals (0–200–400–600 h) in artificial weathering of treated and untreated wood. 相似文献
954.
The present work is an application of iodide to the reduction of gold(III), in an attempt to develop new method for gold(III) based on potentiometric back-titration of the excess of iodide with mercury(II). Although it was proved by calculation that the reduction of tetrachloroaurate to the metal should proceed quantitatively to completion, yet our experiments showed that the reduction under ordinary conditions, gave Au(I) in the form of a white precipitate of AuI. We succeeded to push the reduction with iodide to the metal by an excess of ethanol-ether catalyzed iodide at somewhat elevated temperature.With the experimental conditions established a reliable procedure have been developed involving a potentiometric finish which enabled accurate determination of gold(III), either alone or in some of its alloys. 相似文献
955.
Noureldin M. Ibrahim Ismail H. A. Fattah Mahmoud H. Ahmed 《Fiber and Integrated Optics》1994,13(4):373-379
A design for a 3-dB single-mode Y-junction has been developed and investigated by the beam propagation method with a purpose of decreasing radiation loss in the case of power dividers. The design has two aspects. The first introduces a general design of the boundaries of the 3-dB Y-junction. The second aspect is the replacement of a strip of the guiding material with a lower refractive index near the branching vertex. The design is optimized for low radiation loss, so the output power is increased by 42% over a conventional design. 相似文献
956.
F. Grass H. Holzner A. Ritschel S. S. Ismail J. Dorner 《Journal of Radioanalytical and Nuclear Chemistry》1994,179(1):13-25
Neutron activation analysis (NAA) at various irradiation and measurement systems of the Institute's TRIGA mark II reactor provides a choice of sample oriented analyzing systems. This is demonstrated on the analysis of waste products, on an analysis of the phase content of a high-Tc superconductor and on a fluorine analysis in a standard reference material. 相似文献
957.
958.
The solution and transport of propane in blends of polydimethyl siloxane and poly(ethylene-co-propylene) elastomers has been studied in the range 25–50°C. The dependence of the blend permeability on composition was determined and compared with the Maxwell and other expressions for transport in heterogeneous media. 相似文献
959.
960.
Waleed A. Al-Salam Mourad E.H. Ismail 《Journal of Mathematical Analysis and Applications》1976,55(1):125-139
The concept of “Discrete Convolution Orthogonality” is introduced and investigated. This leads to new orthogonality relations for the Charlier and Meixner polynomials. This in turn leads to bilinear representations for them. We also show that the zeros of a family of convolution orthogonal polynomials are real and simple. This proves that the zeros of the Rice polynomials are real and simple. 相似文献