Ion separation by selective crystallization of organic frameworks

Selective crystallization of organic frameworks is presented as a promising alternative to ion separation from competitive aqueous environments. The review focuses primarily on the principles determining ion selectivity in crystallization, as well as on structure–selectivity relationships. Specific examples involving anion separation by selective crystallization are discussed.     

一种基于EMD的系统误差分离方法

现有的测量误差分离方法大多需要预先确定误差的变化特征和基函数,而基函数的选取没有明确的标准.该文提出了一种采用自适应分解的经验模态法对周期较大的系统误差进行提取和自相关分析与经验模态相结合的分解法对周期较小的系统误差进行提取的方法.通过实际仿真结果表明,自相关分析与经验模态分解法不需要确定误差特征就能够成功分离系统误差与随机误差,达到了预期效果.     

Kinetics of crystallization of a Fe-based multicomponent amorphous alloy

The Fe-based multicomponent amorphous alloys (also referred to as metallic glasses) are known to exhibit soft magnetic properties and, it makes them important for many technological applications. However, metallic glasses are in a thermodynamically metastable state and in case of high temperature operating conditions, the thermally activated crystallization would be detrimental to their magnetic properties. The study of crystallization kinetics of metallic glasses gives useful insight about its thermal stability. In the present work, crystallization study of Fe₆₇Co₁₈B₁₄Si₁ (2605CO) metallic glass has been carried out using differential scanning calorimetry (DSC) technique. Mössbauer study has also been undertaken to know the phases formed during the crystallization process. The alloy shows two-stage crystallization. The activation energy has been derived using the Kissinger method. It is found to be equal to 220 kJ/mol and 349 kJ/mol for the first and second crystallization peaks, respectively. The Mössbauer study indicates the formation of α-(Fe, Co) and (Fe, Co)₃B phases in the alloy.     

Nucleation and crystallization of solids from solution

Over the past couple of years, important insights into the problem of nucleation from solution on the theoretical as well as on the modeling side have been achieved. Experimentally, in situ techniques applied during the nucleation and the crystallization reaction are being developed, which will help to analyze the elementary processes during these reactions. A particularly active field was that of zeolite formation.     

Dry separation of fine particulate sand mixture based on density-segregation in a vibro-fluidized bed

Separation of fine particulate solid materials is one of most important unit operations in industry. Utilization of gas-solid fluidized beds has been considered where particulates are released from constraints due to contacts with surrounding particulates and segregation occurs according to density, size or combination of density and size. Addition of mechanical vibration to the gas-solid fluidized bed may improve dry solid separation. In this study, we investigated the dry separation characteristics of solid particulates using a vibro-fluidized bed especially focusing on the separation of fine particulate ores (≈100 μm) with small density differences. At first, we focused on the influence of fluidizing air velocity on the efficiency of segregation. Subsequently, the influence of vibration strength, vibration amplitude and frequency on segregation behavior was investigated. We found the density segregation does not occur with either gas-fluidization or vertical vibration alone. Only the combination of these effects produces density segregation. The fluidizing air velocity is an important factor to enhance the density-segregation of the particulates with small density difference.     

Acceleration waves through a mixture of two non-linear elastic solids

Summary In this paper we study the propagation of acceleration waves through an anisotropic isothermal mixture of two non-linear elastic solids. First of all, we show that, under suitable hypotheses on the constitutive equations, there exist twelve real normal speeds of propagation; then by means of Nariboli method, we state the evolution law of the discontinuities along the rays associated with the wave front.Work performed under the auspices of C.N.R. (GNFM) and supported by M.P.I. of Italy.     

Longitudinal dispersion in the flow of a multicomponent mixture in a plane channel

The propagation of a multicomponent mixture in a channel is considered. An equation generalizing the well-known Taylor equation [1] both to the multicomponent case and so as to take account of the dependence of the transport coefficients on the concentrations of the components is obtained.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 56, No. 6, pp. 931–936, June, 1989.     

Calculation of thermal-diffusion separation in a mixture of gases

A method for calculating thermal-diffusion separation in a multicomponent mixture of gases is presented that does not require the application of either a thermal-diffusion coefficient or other quantities associated with it (a thermal-diffusion ratio, a factor of thermal diffusion). A comparison of the calculated results with experimental data for binary mixtures is given. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 70, No. 1, pp. 60–63, January–February, 1997.     

Tribo-electrostatic separation of a quaternary granular mixture of plastics

Many tribo-electrostatic separation studies of binary mixtures of millimeter-sized plastic particles have been performed. The objective of this work is an experimental investigation for separating a quaternary mixture comprising four different plastic types issued from waste electrical and electronic equipment. The feasibility of the separation of such quaternary mixtures by the sliding mode tribocharging with a metal wall was demonstrated. The separation of a mixture comprising PA, PC, high impact polystyrene, and polyvinyl chloride granules is better in terms of both purity and recovery when charging the particles by sliding contact with the metal wall, then in the case of a fluidized bed device.     

The Riemann problem for one-velocity model of multicomponent mixture

The exact and approximate solutions of the Riemann problem are given for a one-velocity model of heterogeneous medium which takes into account the internal forces of interfraction interaction. The shock adiabat for mixture, coordinated with the equations of one-velocity model, was used in constructing solutions with shock waves.     

Theoretical investigation of selective dissolution of alloys

We construct a quantum-chemical cluster model of interaction of α-brass and zinc-aluminum and ironchromium alloys with components of an acid aqueous solution of sodium chloride. We established the priority of an increase in the concentration of ions of zinc and iron as compared with the concentration of ions of other metals. The results of computation show that elastic mechanical deformations activate the process of selective dissolution of the alloys considered, which qualitatively agress with the experimental data. Karpenko Physicomechanical Institute, Ukrainian Academy of Sciences, L'viv. Translated from Fizyko-Khimichna Mekhanika Materialiv, Vol. 35, No. 6, pp. 67–71, November–December, 1999.     

Mass transfer in a solid particle with competing reactions with a multicomponent gas mixture

A macrokinetic model of the transformation of a solid particle, reacting with a multicomponent gas mixture, is constructed for arbitrary ratios between the rates of the mass-transfer stages of the transformation process (sorption, dissolution, and diffusion of the starting and final products).Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 51, No. 1, pp. 84–92, July, 1986.     

The Galerkin vector solution for a mixture of two elastic solids and Boussinesq problem

This work is concerned with the linear theory of a binary mixture of two elastic solids. Using the constitutive equations for the mixture which are given by Green and Steel, the displacement equations in the case of isotropic mixture of two elastic solids are derived. By use of the Galerkin vector solution, the displacement vector of each component in the mixture is obtained. Finally, an equilibrium solution for the Boussinesq problem of the mixture of two elastic solids in an infinite half-space is examined.     

基于核典型相关分析的非线性相关源盲分离方法研究

针对传统的相关源盲分离方法的不足,提出了一种基于核典型相关分析的非线性相关源盲分离方法。该方法是利用了核方法来处理数据之间的非线性问题,同时还利用信号源之间的相关性来进行分离。提出的方法与传统的相关源盲分离方法进行对比分析。仿真结果表明,提出的方法明显优于传统的相关源盲分离方法,并从分离性能指标上得到了充分的反映。最后,将该方法应用到转子不对中和碰摩故障的盲分离中,实验结果进一步验证了该方法的有效性。     

Energy bounds for a mixture of two linear elastic solids occupying a semi-infinite cylinder

Summary The aim of this paper is to establish some forms of the Saint-Venant principle for a mixture of two linear elastic solids occupying a semi-infinite prismatic cylinder. We examine the behaviour of the energy for both static and dynamical problems. Under mild assumptions on the asymptotic behaviour of the unknown fields at infinity, we show that in the static case the elastic energy of the portion of the cylinder beyond a distancex ₃ from the loaded region decays exponentially withx ₃. For the dynamical problem we estimate through the data the total energy stored in that part of the cylinder whose minimum distance from the loaded end isx ₃; these estimates, which are based on the assumption that the initial total energy is finite, depend uponx ₃ but do not depend upon the timet.