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991.
An analysis of the solute dispersion in the liquid flowing through a pipe by means of Aris-Barton's ⒈method of moments',under the joint effect of some finite yield stress and irreversible absorption into the wall is presented in this paper.The liquid is considered as a three-layer liquid where the center region is Casson liquid surrounded by Newtonian liquid layer.A significant change from previous modelling exercises in the study of hydrodynamic dispersion,different molecular diffusivity has been considered for the different region yet to be constant.For all time period,finite difference implicit scheme has been adopted to solve the integral moment equation arising from the unsteady convective diffusion equation.The purpose of the study is to find the dependency of solute transport coefficients on absorption parameter,yield stress,viscosity ratio,peripheral layer variation and in addition with various diffusivity coefficients in different liquid layers.This kind of study may be useful for understanding the dispersion process in the blood flow analysis. 相似文献
992.
993.
就石膏墙体材料的轻质化目的,运用两种不同的EPS颗粒的加入工艺,对两种工艺的耐水石膏材料的吸水率、强度等多种系数及性能开展对比研究,最终经过试验验证可知,EPS掺入最优值是1.3%,基于此石膏表观密度是839.06 kg/m~3。干燥时的抗压及抗折度是4.05和2.06 MPa,两者软化系数是0.517和0.650,对比未加EPS颗粒时提升百分比分别为20.8%和11.5%。虽然掺入ESP颗粒后要比未掺入的强度要大,但石膏耐水性获得了显著的提高,并且符合《石膏砌块》以及《建筑隔墙用轻质板条》对于石膏材料的性能要求。 相似文献
994.
995.
K. Dasthaiah B. Robert Selvan A. S. Suneesh M. P. Antony R. L. Gardas 《分离科学与技术》2017,52(14):2308-2317
Aliquat-336-based strongly hydrophobic ionic liquid, tri-n-octylmethylammonium diglycolamate ([A336]+[DGA]?), was prepared and impregnated in Amberlite XAD-7 (abbreviated as [A336]+[DGA]?/XAD-7) for studying the extraction behavior of Am(III) and Eu(III) from nitric acid medium. The distribution ratio of Am(III) and Eu(III) in [A336]+[DGA]?/XAD-7 decreased with an increase in the concentration of nitric acid and the mechanism of trivalent metal ion extraction in the resin phase was elucidated. The uptake of Am(III) and Eu(III) in [A336]+[DGA]?/XAD-7 followed a second order and from the Langmuir adsorption model the apparent europium extraction capacity was determined. The conditions needed for efficient separation of Am(III) from Eu(III) was optimized. 相似文献
996.
In this study, batchwise absorption of CO2 in N-methyl pyrolidone (NMP) was experimentally performed at different conditions using pressure decay method, and as a result, the equilibrium data, Henry’s law constants, and kinetic data were reported. It was shown that solubility and diffusivity are two important factors affecting the kinetic behaviour of the system. This absorption system was mathematically modelled using Fick’s second law accompanied by a time-dependent boundary condition. Thus, the diffusion coefficients of CO2 in NMP were calculated under different operating conditions by means of the experimental kinetic data. Furthermore, the influence of temperature and pressure on the diffusion coefficient of CO2 in NMP was analysed. 相似文献
997.
Mass transfer experiments were carried out in an annular pulsed disc-and-doughnut column (APDDC) using 30% (v/v) TBP-kerosene + uranium nitrate + nitric acid + water system (uranium nitrate system) for both extraction and stripping processes. Parameters in the axial dispersion model (ADM) and plug-flow model (PFM), namely, the axial dispersion coefficient of the continuous phase and the number of mass transfer units, were regressed by correlating the respective model with the experimental concentration profile. The mass transfer coef?cient is calculated, and new correlations are developed to predict the axial mixing coefficient of the continuous phase and the volumetric mass transfer coefficient. The height of a transfer unit is also calculated. The influence of axial mixing on mass transfer performance for the uranium nitrate system is discussed. 相似文献
998.
999.
Absorption methods for the determination of mass transfer parameters of packing internals: A literature review 下载免费PDF全文
Laszlo Hegely John Roesler Pascal Alix David Rouzineau Michel Meyer 《American Institute of Chemical Engineers》2017,63(8):3246-3275
Methods for the determination of mass‐transfer coefficients and effective interfacial areas in packed absorption columns are reviewed. For each parameter, the methods are grouped into categories on the basis of their physical principle; the chemical systems used, experimental protocol, and the advantages and inconveniences are discussed. The treatment of end effects, the influence of packed bed height, and the recent efforts in standardization of measurement methods are also treated. The aim of the review is to give a broad overview of the methods used in literature in the last eight decades, some of which might be reconsidered in the light of modern measurement techniques and to evaluate them in relation to precision, practicality and hazardousness thereby to facilitate the search for reliable, precise, and convenient experimental practices. © 2017 American Institute of Chemical Engineers AIChE J, 63: 3246–3275, 2017 相似文献
1000.
为提高直流微网抗干扰能力,改善系统暂态运行特性,提出了一种基于自适应下垂系数的储能变流器惯性控制方法。基于Matlab/Simulink仿真平台对所提方法进行了对比仿真分析,结果表明:在该控制策略下,直流微网具有较强的抗扰动能力,储能单元能够及时进行功率补给避免了负荷减载,系统供电可靠性和运行稳定性得到了提高。 相似文献