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81.
T. Jeevananda Siddaramaiah Taek Su Lee Joong Hee Lee O. M. Samir R. Somashekar 《应用聚合物科学杂志》2008,109(1):200-210
Polyaniline/carboxylated multi-walled carbon nanotube (PAni/c-MWNT) nanocomposites have been synthesized by micellar aided emulsion polymerization with various c-MWNTs compositions, viz., 0.5, 1, 5, and 10 wt %. The microcrystalline parameters such as the nanocrystal size (〈N〉), lattice strain (g), interplanar distance (dhkl), width of the crystallite size distribution, surface weighted crystal size (Ds), and volume of the ordered regions were calculated from the X-ray data by using two mathematical models, namely the Exponential distribution and Reinhold distribution methods. The effects of heat ageing on the microcrystalline parameters of the PAni/c-MWNT nanocomposites were also studied and the results are correlated. The thermal stability and electrical resistivity of the PAni/c-MWNT nanocomposites were examined with thermogravimetric analysis (TGA) and a conventional two-probe method. The TGA data indicate that the thermal stability of the nanocomposites improved after the incorporation of c-MWNTs. The influence of temperature on the resistivity of the nanocomposites was also measured. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci 2008 相似文献
82.
The swelling kinetics curves of structurally defined poly(acrylic acid) hydrogel in bidistilled water at temperatures: 25, 30, 35, 40, and 45°C were determined. The possibility of kinetically explaining the isothermal swelling process by applying the following models: reaction controlled by diffusion, first order chemical reaction kinetics, and second order chemical reaction kinetics, was investigated. It was found that kinetically explaining the swelling process using these methods was limited to only certain parts of the process. The swelling process in bidistilled water was described in full range assuming that the hydrogel's swelling rate was a kinetically controlled reaction by the rate of the movement of reactive interface of hydrogel. Based on that model, the kinetic parameters, activation energy (Ea) and preexponential factor (A), of the swelling process were determined to be Ea = 35 kJ/mol and lnA = 8.6. A possible mechanism of the investigated swelling process was discussed. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
83.
Hsu‐Wei Fang Hsien‐Chieh Wang Teh‐Hua Tsai Wei‐Bor Tsai Shao‐Yi Hou Hsuan‐Liang Liu Wun‐Hsing Lee Yung‐Chang Lu Chun‐Hsiung Huang 《应用聚合物科学杂志》2008,108(4):2428-2437
Wear of ultrahigh‐molecular‐weight polyethylene (UHMWPE) and wear‐particle‐induced osteolysis and bone resorption are the major factors causing the failure of total joint replacements. It is feasible to improve the lubrication and reduce the wear of artificial joints. We need further understanding of the lubrication mechanism of the synovial fluid. The objective of this study is to evaluate the lubricating ability of three major components in the synovial fluid: albumin, globulin, and phospholipids. An accelerated wear testing procedure in which UHMWPE is rubbed against a microfabricated surface with controlled asperities has been developed to evaluate the lubrication behavior. An analysis of the wear particle dimensions and wear amount of the tests has provided insights for comparing their lubrication performance. It is concluded that the presence of biomolecules at the articulating interface may reduce friction. A higher concentration of a biological lubricant leads to a decrease in the wear particle width. In addition, in combination with the wear results and mechanical analysis, the roles of individual biomolecules contributing to friction and wear at the articulating interface are discussed. These results can help us to identify the role of the biomolecules in the boundary lubrication of artificial joints, and further development of lubricating additives for artificial joints may be feasible. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
84.
ABSTRACT: Popcorn was oiled and coated in a tumble drum nonelectrostatically and electrostatically with sugar, cornstarch, salt, cellulose, maltodextrin, all-purpose flour, whole-wheat flour, or soy flour. Particle size, density, flowability, and chargeability were correlated to transfer efficiency using regression analysis. Of the various methods to measure chargeability, charge-to-mass and adhesion improvement were the most significant. For nonelectrostatic coating, small, dense, free-flowing powders were most efficient. Small, free-flowing highly charging powders were most efficient for electrostatic coating. Percent improvement was the highest for the least efficient powders. The greatest benefit with electrostatic coating was for low density, highly charging powders with no effect of size. 相似文献
85.
文章较系统地论述了车铣复合机床设计方案的形成过程,同时分析了该设计方案的持点,并简要介绍了该产品的主要技术参数和用途,简评了该产品的技术水平。 相似文献
86.
厅堂音质评价参量的相关性分析 总被引:2,自引:1,他引:1
当代室内声学专家经常选用的评价厅堂音质的物理参量,其间有几个量是相关的。作为室内音质设计的依据.必须寻找基本相互独立的参量,才有更大的实用意义。 相似文献
87.
A test chamber has been developed in order to provide a small and simple emission testing facility capable of testing construction products in a climate where the important climatic parameters such as temperature, ventilation rate and air velocity can be varied independently around typical indoor values. The test chamber CLIMPAQ is made of panes of window glass. Other main surface materials are stainless steel and eloxated aluminium. The chamber has a volume of 50.9 litres and is designed to meet the requirements for quantifying air pollution. In this investigation human subjects acted as air pollution judges, and chemical characterization of the air pollution was carried out. Carpet, linoleum, wall paint and seal- ant were tested simultaneously in the CLIMPAQ and in four other chambers ranging from a full-scale chamber of 28 m3 to a field and laboratory emission cell of 3.5· 10?5m3. Product ranking is the same in all chambers for the sensory measurements. Emission rates based on sensory measurements differ for all products less than 100 % except for tests in a 3-litre chamber where emission rates were higher. Chemical measurements differ up to approximately 10 times for the same product in different chambers. Deviations appear to be the result of different environmental parameters in the various chambers. Low air concentrations or high specific ventilation rates seem to increase emissions, while differences in air velocities and sink properties may also be the cause of differences in emission rates. 相似文献
88.
Dr. C. R. Nagarajah W. Thompson 《The International Journal of Advanced Manufacturing Technology》1994,9(5):333-342
There are two aspects to cell formation in flexible manufacturing systems, cell sizing or deciding on the optimum number of machines to be allocated to each cell, and then allocation of specific machines to each cell. Although the latter problem has been investigated extensively there is a paucity of published work on the former. This paper discusses the effects of cell sizing on operational flexibility.Operational flexibility is that aspect of flexibility that enables manufacturing systems to respond with speed and efficiency to changes in the manufacturing environment while maintaining an effective level of control. 相似文献
89.
G. Mestres F. Niefloud R. Fortune J. M. Devoisselle R. Marti H. Maillols 《Drug development and industrial pharmacy》1996,22(12):1193-1199
This paper reports a study undertaken using techniques of static and dynamic light scattering to investigate the influence of sodium salicylate and methyl salicylate on droplet size of oil-in-water emulsions. The rates of changes were measured by determining the size and distribution of the oil droplet in the material. All emulsions showed a bimodal size distribution; the mean diameters and polydispersity were calculated from intensity. These data were analyzed with nonlinear regressions and bootstrap methodology. An amount of methyl salicylate component induced a decrease of mean diameter and standard deviation. On the contrary, sodium salicylate entailed the growth of all droplet populations and coalescence for the highest concentration. 相似文献
90.
CH_4、CO_2与O_2制合成气的研究 Ⅱ工艺条件的影响 总被引:1,自引:0,他引:1
在固定床反应器中考察了12%Ni-5%RE-2%Cu-2%Li/Al2O3(mass)催化剂在CH4、CO2与O2催化氧化重整制合成气反应中催化剂粒径、工艺操作条件(空速与温度)及原料气配比对反应的影响,确定了较佳的操作条件:催化剂粒径20~40目,反应最佳温度为800℃,SV=4×104ml/(g·h)。同时看到在不同的原料气配比的条件下该催化剂的活性亦很稳定,不仅达到了反应平衡,且产物V(CO)/V(H2)比有很强的调变性。 相似文献