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Defence Technology（防务技术） 2018年第3期14卷 238-249页

作者： Edison E.Haro jerzy a.szpunar Akindele G.Odeshi Department of Mechanical Engineering University of Saskatchewan

The mechanical behavior of chonta palm wood(Bactris gasipaes) microparticles reinforced high density polyethylene(HDPE) under high strain-rate compressive and ballistic impact loading were *** palm wood microparticles were introduced into the HDPE via an extrusion process using parallel twin screw extruder to produce biocomposite containing 10, 20, 25, and 30 wt % chonta wood microparticles. In addition to mechanical tests, fractographic analysis was done to understand the failure mechanism in the biocomposites under dynamic and ballistic impact loads. The results indicate that both quasi-static and dynamic mechanical properties of HDPE are enhanced by reinforcement with chonta palm wood particles. The biocomposites containing 25 wt % wood microparticles exhibited the highest strength, stiffness, ballistic impact resistance and impact energy absorption capability. Introduction of microparticles of chonta palm wood as reinforcement into a polymeric matrix such as HDPE is therefore a promising method to develop biocomposites with enhanced capacity to withstand dynamic impact loading and absorb impact energy.

关键词： HDPE 弹道行为盔甲机械测试吸收能力密度聚乙烯挤出过程

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Correlation Between Magnetic Properties and Allotropic Phase Transition of Fe–Co–V Alloy

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Acta Metallurgica Sinica(English Letters) 2015年第8期28卷 1055-1058页

作者： Saeed Hasani Ali Shafyei Morteza Shamanian Peiman Behjati Hossein Mostaan Timu Juuti jerzy a.szpunar Department of Materials Engineering Isfahan University of Technology Department of Materials and Metallurgical Engineering Arak University Centre for Advanced Steels Research University of Oulu Department of Mechanical Engineering University of Saskatchewan

In this study, the allotropic phase transition and its effect on the magnetic behavior of Fe Co–7 wt%V alloy were investigated. It was found that c phase is observed in the microstructure in the as-cast condition, and it diminishes after severe cold rolling（90% reduction）. After annealing at temperatures higher than 500 up to 750 ℃, the c phase is observed in the structure, again. But, this phase is disappeared by annealing at temperatures above 750 ℃ due to the formation of vanadium-rich precipitates. Thermocalc software was used in order to elucidate the influence of vanadium percent on the stability of c phase in Fe–Co alloys. Also, magnetic studies showed that the saturation induction is reduced by annealing at temperatures from 500 up to 750 ℃, which is related to the formation of residual non-magnetic γ phase.

关键词： Fe–Co–V alloy Thermocalc software Magnetic material Phase transformation Electron backscatter diffraction(EBSD)

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Structure,Texture and Magnetic Properties of Laser-Welded Ultrathin Fe-Co-V Foils

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Acta Metallurgica Sinica(English Letters) 2015年第3期28卷 338-347页

作者： Hossein Mostaan Morteza Shamanian Seyed Mahmoud Monirvaghefi Peiman Behjati jerzy a.szpunar Morteza Amiri Mashallah Fathi Moghadam Department of Materials Engineering Isfahan University of Technology Department of Mechanical Engineering University of Saskatchewan Department of Materials Engineering Yazd University Department of Materials Science and Engineering Sharif University of Technology

This research aims to investigate the effect of pulsed Nd：YAG laser micro-welding on the microstructure,texture and magnetic properties of ultra-thin Fe-Co-7.15 wt%V magnetic *** microscopy,scanning electron microscopy and electron backscattered diffraction techniques were used to study the microstructural ***,vibrating sample magnetometry was used to characterize the magnetic *** results showed that the fractions of low Σ coincidence site lattice boundaries in the fusion zone are higher than those of the base *** welded samples experience a significant decrease in their magnetic *** was found that the formation of new fiber texture in the fusion zone and grain coarsening are the most important factors affecting the magnetic properties.

关键词： Magnetic properties Ultra-thin magnetic foils Texture analysis EBSD study Nd:YAG laser micro-welding

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Bioinspired and hydrophobic alkyl-silanized protective polymer coating for Mg alloy

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Progress in Natural Science:Materials International 2018年第3期28卷 354-362页

作者： Ubong Eduok jerzy szpunar Department of Mechanical Engineering College of EngineeringUniversity of Saskatchewan

The modification of silica coating surfaces by trimethylsilylation has contributed to enhanced hydrophobicity（θw~o>90°）against fluid permeation and corrosion in Na *** alkyl-silanized coatings were deployed to protect Mg alloy after reinforcing their internal structures with nanosilica *** reduced wetness of coating surfaces is attributed to their chemically-modified surface morphology,and this has been compared to the reticulate leaf structures of lotus *** optimum amount of silylating additive（hexamethyldisilazane）required to prepare a hydrophobic coating with minimum water adhesion has been *** performance of coatings were examined by electrochemical and surface analyses in 5 wt%Na *** corrosion resistance of these coatings is a result of the direct contribution of their bulk stability and surface hydrophobicity,and this is expressed in terms of the variation of electrochemical parameters with exposure *** coatings may have emerging industrial applications,including a future in metal surface treatments and anticorrosion paints.

关键词： Alkyl-silanized coating Mg alloy corrosion Surface properties Contact angle Hydrophobicity Lotus leaf

Electronic Transport of Uranium Mononitride

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Journal of Modern Physics 2021年第10期12卷 1409-1417页

作者： Barbara.szpunar Jayangani I. Ranasinghe jerzy A. szpunar Department of Physics and Engineering Physics University of Saskatchewan Saskatoon Canada Department of Mechanical Engineering University of Saskatchewan Saskatoon Canada

We investigated the electronic heat capacity, thermal conductivity, and resistivity of UN using Quantum Espresso and EPW code. GGA, PBEsol functional was used. The calculated electronic heat coefficient was found to be significantly reduced (0.0176 J⋅mol-1⋅K-2 versus 0.0006 J⋅mol-1⋅K-2) when the non-local hybrid functional (B3LYP) was used. Furthermore, we calculated electrical resistivity using a very transparent Ziman’s formula for metals with the Eliashberg transport coupling function as implemented in EPW code for non-spin-polarized calculations. The number of mobile electrons in UN, as a function of temperature, was derived from the ratio of the calculated resistivity and available experimental data. The electronic thermal conductivity was evaluated from the calculated electronic resistivity via Wiedemann-Franz law with the number of mobility electrons (nav) incorporated (averaged over the temperature range 300 K - 1000 K). Both the electronic thermal conductivity and resistivity, as calculated using newly evaluated nav, compare well with experimental data at ~700 K, but to reproduce the observed trend as a function of temperature, the number of mobile electrons must decrease with the temperature as evaluated.

关键词： UN Electronic Thermal Conductivity Electronic Structure Number of Mobility Electrons Quantum ESPRESSO EPW Codes

Effects of Orientation of Carbon Nanotubes on CNT Bundle Based Silk Composite Using Finite Element Method

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Modeling and Numerical Simulation of Material Science 2013年第1期3卷 33-38页

作者： Md Shihamul Islam jerzy szpunar Department of Mechanical Engineering University of Saskatchewan Saskatoon Canada

Carbon Nanotubes (CNTs) have exceptional mechanical properties. They are the stiffest and strongest material, yet discovered, because of their high length to diameter ratio. In this paper a Representative Volume Element (RVE) model of CNT-silk composite is made. Then the orientations of the CNTs in the composite are varied and the effects of this variation are observed. The change is mainly observed between the interfaces of CNT and silk. Also there is a change in Young’s Modulus. COMSOL Multiphysics 4.2a is used for building model and performing simulations.

关键词： Carbon Nanotubes (CNTs) Orientation Interface Young’s Modulus RVE FEM COMSOL Multiphysics 4.2a

Study of Dialyzer Membrane (Polyflux 210H) and Effects of Different Parameters on Dialysis Performance

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Open Journal of Nephrology 2013年第3期3卷 161-167页

作者： Md Shihamul Islam jerzy szpunar Department of Mechanical Engineering University of Saskatchewan Saskatoon Canada

Problems frequently encountered in kidney malfunction include abnormal fluid levels in the body, increased acid levels, abnormal levels of Urea, Glucose, Endothelin, β2-Microglobulin and Complement Factor D. Parameters characterizing the structure of dialyzers are very important because they decide overall clearance of toxin molecules and at the same time should allow retaining useful molecules in the blood. In this paper, a cross sectional image of the dialyzer membrane with details of the porosity is presented. A multilayered membrane model with different porosity for each layer, describes the actual structure of Polyflux 210H membrane. This model is developed using Finite Element Software—COMSOL Multiphysics 4.3. A blood flow with substances like—Urea, Glucose, Endothelin, β2-Microglobulin, Complement Factor D and Albumin is introduced. For a certain blood flow rate, the toxins diffuse through the membrane and on the other side of the membrane a dialysate flow removes the toxins. Here, different parameters, such as flow rate of blood and dialysate, length and radius of the fiber are changed to simulate how these changes affect toxin clearance and the removal of useful molecules.

关键词： Simulation Dialysis Axisymmetric Model 3-Layered Membrane Effective Diffusivity Parameters COMSOL Multiphysics 4.3