Montreal, QC | Canada
Main Specialties: Chemistry
Additional Specialties: Mathematical Modeling & Simulation
Alireza grew up in Tehran, Iran where he attended high school majoring in mathematics. He received his B.Sc. in Chemical Engineering (2004) and M.Sc. in Transport Phenomena & Separation Processes (2007) from the Department of Chemical and Petroleum Engineering at Sharif University of Technology. Then he attended the Zeolite Research Group (2008) where he was a researcher in the Science and Technology Park of Tehran University. Before beginning his Ph.D. in Materials Modeling, Alireza worked as a researcher and consulting engineer for two companies, MME Gmbh & Daneshpajouhan, where he conducted several industrial projects in oil, natural gas, and metal fields. In 2010 Alireza immigrated to Canada where he obtained his Ph.D. in Chemical Engineering (2015) at McGill University, working under the supervision of Prof. Alejandro D. Rey, and received several awards and fellowships. He collaborated with Prof. Mohan Srinivasarao’s Laboratory of Liquid Crystals and Soft Matters at Georgia Institute of Technology. Then he completed his Post-Doctoral Research Fellow (research consultant) at Yale School of Public Health and UiT the Arctic University of Norway in 2017, working with Dr. Ted Cohen and Dr. Abel zur Wiesch. Recently he was a Senior R&D Scientist and Process Specialist at Sigma Storage Energy Inc. in Montreal and now he is working as a postdoc fellow at Polytechnique Montreal.
Besides the academic and industrial experiences, Dr. Shams is a poet, writer, translator, and literary critic. His literary activity since 2001 began with founding Cactus Magazine in Sharif University of Technology and he was the chief editor of it for more than two years. Since his arrival in Montreal, he became the literary editor of the weekly Iranian magazine (Hafteh) and He established the Persian Poetry Association in Montreal on May 2013. Also, Dr. Shams is the Vice-President for Cultural and Educational Affairs in Hope for Children with Cancer non-profit organization. So far, he has eight published poetry books and two other books in press.
Primary Affiliation: Polytechnique Montréal - Montreal, QC , Canada
JOM (2015) 67: 2681
Journal of Minerals, Metals and Materials Society
Metallic iron used in steel industries is mostly obtained from a direct reduction process. The focus of this study is to simulate the furnace of the MIDREX technology. MIDREX technology which is the most important gas-based direct reduced iron (DRI) process in the world, includes reduction, transition and cooling zones. The reduction zone considered as a counter current gas–solid reactor produces sponge iron from iron ore pellets. The transition zone has sufficient height to isolate the reduction zone and cooling zone from each other and the cooling zone cools the solid product down to around 50°C. Each zone has a system of reactions. Simultaneous mass and energy balances along the reduction zone lead to a set of ordinary differential equations with two points of boundary conditions. The transitions and cooling zone are investigated at the equilibrium condition leading to a set of algebraic equations. By solving these systems of equations, we determined the materials concentration, temperature, and pressure along the furnace. Our results are in a good agreement with data reported by Parisi and Laborde (2004) for a real MIDREX plant. Using this model, the effect of reactor length and cooling gas flow on the metallization and the effect of cooling gas flow on the outlet temperature of the solid phase have been studied. These new findings can be used to minimize the consumed energy.
Molecular Crystals and Liquid Crystals, 612:1, 56-63
Molecular Crystals Liquid Crystals
When a nematic liquid crystal is confined to a capillary tube with strong homeotropic anchoring conditions, unstable +1 disclinations lines can branch into a pair of +1/2 lines forming loops attached to the +1 axial line through branch points. The shape of the +1/2 disclination lines is a function of the confinement and the Frank elasticity. Our previous work shows that nematic liquid crystals under cylindrical confinement display a radial-to-planar polar defect texture transition through the nucleation and uniform motion of a disclination branch point that separates a high charge disclination from two lower charge ones. Here, we present the existence of a branch point for a nematic LC confined to different conical geometries with homeotropic anchoring. Determination of the defect geometry in conjunction with our model provides a means of characterizing the elasticity of LCs. Our results show that a larger conical angle reduces the length at which disclination curvature relaxes to zero and it also leads to less bending energy. These new findings are useful to assess the Frank elasticity of the nematic LCs and predict novel defect structures under confinement.
Liquid Crystals, 42:4, 506-519
We present analysis, scaling and modelling based on a previously presented nonlinear nonlocal nematic elastica equation of disclination loop growth in nematic liquid crystals conﬁned to conical geometries with homeotropic anchoring conditions. The +1/2 disclination loops arise during the well-known planar radial to planar polar texture transformation and are attached to +1 singular core disclination at two branch points. The shape of the +1/2 loops is controlled by the axial speed of the branch points and the bending stiffness of the disclination both of which being affected by the confinement gradients (reduction in cross-sectional area) of a conical geometry. Motion towards the cone apex results in faster branch point motions and weaker curvature changes, but motion away from the apex results in slower branch point motion and stronger curvature changes. The simultaneous action of these effects results in novel ovoidal disclination loops. The numerical results are condensed into useful power laws and integrated into a shape/energy analysis that reveals the effects of confinement and its gradient on ovoidal disclination loops. These new findings are useful to characterise the Frank elasticity of new nematic mesophases and to predict novel defect structures under complex confinement.
Phys Rev E Stat Nonlin Soft Matter Phys 2014 Oct 14;90(4):042501. Epub 2014 Oct 14.
Department of Chemical Engineering, McGill University, Montreal, Quebec H3A 0C5, Canada.
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MRS Proceedings, 1526, Mrsf12-1526-tt03-10.
Mater. Res. Soc. Symp. Proc
Nematic liquid crystals (NLCs) under micron-range confinement exhibit a rich defect phenomenology that can be used to extract elastic (Frank moduli) material parameters of critical importance for next generation electro-optical devices. In this work we develop a model to predict defect-driven textural transformations that arise when a NLC is confined to a circular capillary. In the initial transformation stage an unstable disclination defect of strength +1 nucleates in the axis of the capillary and quickly branches into two stable +1/2 disclination defects. The model includes: (1) the Kirchhoff branch balance equation which predicts the splitting of a +1 into two +1/2 wedge disclinations; (2) the curvature of the +1/2 disclination lines as a function of elastic properties. This model shows that by increasing the ratio of tension strength to bending stiffness, the branch point angle increases, but the final defect distance decreases; and (3) the aperture branching angle of the +1/2 lines as a function of the elastic properties and the magnitude of the curvature at the branch point. These three predictions form the basis for the evaluation of the Frank elastic moduli on NLCs. The key advantage of the implemented methodology is to use time-dependent textural transformations under micron-range capillary confinement to extract elastic parametric data needed to further develop NLCs in functional and structural application.
Soft Matter, 2012,8, 11135-11143
Defects in nematic liquid crystals under controlled confinement serve as a useful tool to characterize material properties as well as to reveal texture stability and pattern formation mechanisms in anisotropic soft matter. In particular, nematics inside micro-capillaries can exhibit a large variety of textures with point defects, line defects and loop defects, whose stability is dictated by factors such as geometry and temperature. In this paper we present a theoretical model, scaling, and simulation of a texture transition between two commonly observed patterns (planar polar and radial), through the uniform translation of a shape-invariant disclination branch point in generic calamitic nematic liquid crystals under capillary confinement and strong radial anchoring. Using the “nematic elastica” model derived from the Q-tensor Landau–de Gennes and n-vector Frank–Oseen equations, the geometry, stability, and energetics of disclination branching of a straight high order +1 disclination into a pair of curved +1/2 disclinations under capillary confinement are fully characterized, including the branch angle, the curvature and final separation of the +1/2 lines, and the scaling of these quantities with the capillary radius (R). It is found that the branching and disclination shapes adjust to the capillary confinement by regulating their tension-to-bending stiffness ratio in such a way that the resulting branch angle is close to π/3, the branch curvature is 3/R and the final disclination distance is Image ID:c2sm26595h-t1.gif. These new findings based on the “nematic elastica” are also useful to predict other novel structures that arise in conical and toroidal geometries of current interest and can be used to assess the Frank elasticity of nematic liquid crystals.
Energy Fuels, 2008, 22 (1), pp 570–575
Energy & Fuels
This paper deals with the modeling and simulation of binary liquid-phase adsorption of methyl mercaptan and hydrogen sulfide from a liquid butane stream by zeolite molecular sieve 13X in a fixed bed. The model equations account for the effect of axial dispersion and the inter- and intraparticle mass-transfer resistances at isothermal operating conditions. Orthogonal collocation and Gill’s fourth-order Runge–Kutta methods were used to solve the dimensionless general forms of the 4N-coupled ordinary differential equations for simultaneous adsorption of the solutes by the adsorbent in a fixed bed. The model predictions were compared to the commercial-scale plant data of an Iranian petrochemical company (Bandar Imam, Iran), and a fair agreement was observed for the fixed-bed absorber of 1.7 m in diameter and 5.06 m in height. Moreover, the influences of the bed Reynolds number, Peclet number, total inlet sulfur concentration, feed temperature, and diameter of the spherical adsorbent on the breakthrough curve were investigated.