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71.
A. R. Moghadassi S. M. Hosseini B. Yasini E. Joudaki A. R. Fazlali 《Petroleum Science and Technology》2013,31(10):1036-1045
Abstract Optimization in the chemical and petroleum industry is gaining increased interest because of its importance in maintaining product quality and enhancing production levels while improving profit margins. In this article, simulation of the atmospheric distillation unit of an existing petroleum refinery is carried out. Optimization was performed on the prepared simulation through the use of a sequential quadratic programming approach (SQP). The objective function consisted of energy minimization and production level maximization. The results obtained from optimization were implemented on the real process and it was demonstrated that the suggested changes increased overhead production levels and maintained product quality. Furthermore, a net economical balance between the increment of overhead products and the energy consumption showed an energy savings in the refinery. 相似文献
72.
73.
The main aim of this article is studying the coupled sine-Gordon equations in nonlinear optics, which describe the propagation of an optical pulse in fibre waveguide. New exact solutions of the coupled sine-Gordon equations have been derived through the use of the well-organized modified Kudryashov method. 相似文献
74.
本实验用东洋曹达 HLC-802A GPC 仪考察了几种窄分布聚苯乙烯样品和两种宽分布聚苯乙烯样品.结果表明:(1)在0.10~0.15g/100ml 浓度以下几乎没有浓度效应.(2)浓度再增加,淋洗体积随之增加。(3)分子量随浓度增加而降低,且峰加宽.(4)分子量大者,浓度效应显著.窄分布样品比宽分布样品明显.(5)流速大,浓度效应显著. 相似文献
75.
甲基丙烯酸N,N-二甲氨乙酯(DMAEMA)与溴正丁烷在丙酮溶剂中进行季铵化反应,制得甲基丙烯酸季铵盐酯(MBDM);然后以AIBN为引发刑,MBDM与苯乙烯(St)在溶液中进行自由基共聚,制得阳离子共聚物P(MBDM-St),其结构用红外光诸法鉴定,并经 ̄1HNMR和元素分析表征,证实有可能根据δ2.8~4.1和δ7.22处两个共振峰确定共聚物的组成. 相似文献
76.
中空玻璃微珠填充环氧树脂复合材料 总被引:5,自引:0,他引:5
讨论了用发电厂固体废料中的中空玻璃微珠填充E-44环氧树脂制备轻质复合材料,实验详尽地考察了微珠填料,KH-500偶联剂,固化剂(三乙基四胺,T-31,三乙醇及液体四氢苯酐)及低聚酰胺等增韧剂等对所得的复合材料为力学性能的影响,并通过扫描电镜(SEM)观察了材料的形态,其结果表明,偶联剂和增韧剂对复合材料的力学性能影响较大,中空玻璃微珠填充环氧树脂赋予基轻质,高强,价廉等特性。 相似文献
77.
An investigation into the wear process of five polymers tested under different contact conditions is presented. Polymer pin on metal plate and metal pin on polymer plate configurations were used. The metal pin on polymer plate configuration gave significantly lower wear rates compared to that observed for the polymer pin on metal plate configuration. The results are discussed in terms of morphology of wear debris generated. 相似文献
78.
A Schiff base complex of Zn(II) as a neutral carrier for highly selective PVC membrane sensors for the sulfate ion 总被引:1,自引:0,他引:1
Shamsipur M Yousefi M Hosseini M Ganjali MR Sharghi H Naeimi H 《Analytical chemistry》2001,73(13):2869-2874
Novel polymeric membrane (PME) and coated graphite (CGE) sulfate-selective electrodes based on a recently synthesized Schiff base complex of Zn(II) were prepared. The electrodes reveal a Nernstian behavior over wide SO4(2-) ion concentration ranges (5.0 x 10(-5)-1.0 x 10(-1) M for PME and 1.0 x 10(-7)-1.0 x 10(-1) M for CGE) and very low detection limits (2.8 x 10(-5) M for PME and 8.5 x 10(-8) M for CGE). The potentiometric response is independent of the pH of the solution in the pH range 3.0-7.0. The electrodes manifest advantages of low resistance, very fast response, and, most importantly, good selectivities relative to a wide variety of other anions. In fact, the selectivity behavior of the proposed SO4(2) ion-selective electrodes shows a great improvement compared to the previously reported electrodes for sulfate ion. The electrodes can be used for at least 3 months without any appreciable divergence in potentials. The electrodes were used as an indicator electrode in the potentiometric titration of sulfate and barium ions and in the determination of iron in ferrous sulfate tablets. 相似文献
79.
Thermoelastic analysis of a functionally graded rotating disk 总被引:2,自引:0,他引:2
A semi-analytical thermoelasticity solution for hollow and solid rotating axisymmetric disks made of functionally graded materials is presented. The radial domain is divided into some virtual sub-domains in which the power-law distribution is used for the thermomechanical properties of the constituent components. Imposing the necessary continuity conditions between adjacent sub-domains, together with the global boundary conditions, a set of linear algebraic equations are obtained. Solution of the linear algebraic equations yields the thermoelastic responses for each sub-domain as exponential functions of the radial coordinate. Some results for the stress, strain and displacement components along the radius are presented due to centrifugal force and thermal loading. Results obtained within this solution are compared with those of a finite element analysis in the literature. Based on the results, it is shown that the property gradation correlates with thermomechanical responses of FG disks. 相似文献
80.
Mehran Hosseini Guchuan Zhu Yves-Alain Peter 《Analog Integrated Circuits and Signal Processing》2007,53(2-3):119-128
Though the effect of fringing field in electrostatic parallel-plate actuators is a well-understood phenomenon, the existing
formulations often result in complicated mathematical models from which it is difficult to determine the deflection of the
moving plate for given voltages and hence, they are not suitable for accurate actuation control. This work presents a new
formulation for tackling the fringing field, in which the effect of fringing field is modeled as a variable serial capacitor.
Based on this model, a robust control scheme is constructed using the theory of input-to-state stabilization (ISS) and backstepping
state feedback design. This method allows loosening the stringent requirements on modeling accuracy without compromising the
performance. The stability and the performance of the system using this control scheme are demonstrated through both stability
analysis and numerical simulation. 相似文献