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Determining the impact of rectangular grain aspect ratio on tortuosity–porosity correlations of two-dimensional stochastically generated porous media

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science Bulletin 2016年第8期61卷 601-611页

作者： A.Ebrahimi Khabbazi J.Hinebaugh A.Bazylak Thermofluids for Energy and Advanced Materials (TEAM) Laboratory University of Toronto Department of Mechanical and Industrial engineering University of Toronto faculty of applied science and engineering University of Toronto

Tortuosity is an important parameter for char- acterizing transport properties within porous materials and is of interest in a broad range of fields, such as energy storage and conversion materials. One of the parameters that impacts the tortuosity value is the geometry of the solid phase which, in this study, is considered as stochas- tically-placed rectangular particles. Through lattice Boltz- mann modelling （LBM）, we determined the impact of particle aspect ratio on the intrinsic tortuosity-porosity relationships of two-dimensional porous media composed of rectangular particles. These relationships were isolated for materials with grain （particle） aspect ratios of e { 1, 2, 3 } and porosities from [0.55 - 0.95]. We determined that a minimum of 6, 8 and 10 stochastic simulations, respec- tively, were required to calculate these average tortuosity values in laminar flow （Re 〈〈 1）. This novel application of the LBM to study the effects of porosity and aspect ratio of rectangular grains on tortuosity can be used in the tailoring of materials for clean energy.

关键词： Tortuosity ~ Porous media ~ Grain aspectratio ~ Lattice-Boltzmann model - Stochasticsimulation

Mathematical and numerical modelling of large creep deformations for annular rotating disks

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applied Mathematics and Mechanics(English Edition) 2015年第11期36卷 1441-1448页

作者： K.SZUWALSKI A.USTRZYcKA faculty of Mechanical engineering Institute of Applied MechanicsCracow University of Technology

A simulation model is presented for the creep process of the rotating disks under the radial pressure in the presence of body forces. The finite strain theory is applied. The material is described by the Norton-Bailey law generalized for true stresses and logarithmic strains. A mathematical model is formulated in the form of a set of four partial differential equations with respect to the radial coordinate and time. Necessary initial and boundary conditions are also given. To make the model complete, a numerical procedure is proposed. The given example shows the effectiveness of this procedure. The results show that the classical finite element method cannot be used here because both the geometry and the loading （body forces） change with the time in the creep process, and the finite elements need to be redefined at each time step.

关键词： creep process rotating disk finite strain theory simulation model

Heat Transfer and Thermal characteristics Effects on Moving Plate Impinging from cu-Water Nanofluid Jet

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Journal of Thermal science 2020年第1期29卷 182-193页

作者： DATTA Abanti KUMAR Sonal HALDER Pabitra Department of Aerospace engineering and applied Mechanics Indian Institute of Engineering Science and Technology

The present article is focused on modelling of flow and heat transfer behaviour of cu-water nanofluid in a confined slot jet impingement on hot moving *** parameters such as various moving plate velocities,nanoparticles at various concentrations,variation in turbulent Reynolds number and jet nozzle to plate distance have been considered to study the flow field and convective heat transfer performance of the *** of distribution of local and average Nusselt number and skin friction coefficients at the plate surface are shown to elucidate the heat transfer and fluid flow *** analysis of both stream function and isotherm contours are carried out to perceive the flow pattern and heat transfer mechanism due to moving *** results revealed that average Nusselt number significantly rises with plate velocity in addition with jet inlet Reynolds *** of the average Nusselt numbers are presented.

关键词： cu-water nanofluid,multiphase mixture model moving plate jet impingement cFD

Recent advances in myeloid-derived suppressor cell biology

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Frontiers of Medicine 2021年第2期15卷 232-251页

作者： Mahmoud Mohammad Yaseen Nizar Mohammad Abuharfeil Homa Darmani Ammar Daoud Department of Biotechnology and Genetic engineering Department of applied Biology Faculty of Science and Arts Department of Internal Medicine Faculty of MedicineJordan University of Science and TechnologyIrbid 22110Jordan

In recent years,studying the role of myeloid-derived suppressor cells(MDScs)in many pathological inflammatory conditions has become a very active research *** the role of MDScs in cancer is relatively well established,their role in non-cancerous pathological conditions remains in its infancy resulting in much *** objectives in this review are to address some recent advances in MDSc research in order to minimize such confusion and to provide an insight into their function in the context of other *** following topics will be specifically focused upon:(1)definition and characterization of MDScs;(2)whether all MDSc populations consist of immature cells;(3)technical issues in MDSc isolation,estimation and characterization;(4)the origin of MDScs and their anatomical distribution in health and disease;(5)mediators of MDSc expansion and accumulation;(6)factors that determine the expansion of one MDSc population over the other;(7)the Yin and Yang roles of ***,the functions of MDScs will be addressed throughout the text.

关键词： non-human primates(rhesus macaques) myeloid-derived pro-inflammatory cells(MDPcs) autoimmune disorders alloimmune responses pregnancy mature MDScs multiple sclerosis Yin-Yang law of MDScs

A new numerical method to solve modified Reynolds equation for magnetic head/disk working in ultra-thin gas films

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science china(Technological sciences) 2008年第4期51卷 424-434页

作者： Howard H HU School of engineering and applied science University of Pennsylvania

The modified Reynolds equation for ultra-thin gas films between magnetic head; disk assembly is difficult to solve with conventional numerical methods, since the bearing number is very large; there exist boundary layers where pressure changes rapidly. An iterative finite difference algorithm is introduced to solve the nonlinear modified Reynolds equation, with special treatment for the abrupt change in the thickness of the gas film. The numerical results for two types of magnetic heads demonstrate that the scheme is effective.

关键词： finite difference method ultra-thin gas film lubrication magnetic head/disk

Surfactant and nanoparticle synergy:Towards improved foam stability

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Petroleum 2023年第2期9卷 255-264页

作者： Arifur Rahman Farshid Torabi Ezeddin Shirif Petroleum Systems engineering Faculty of Engineering and Applied ScienceUniversity of ReginaReginaSK S4S 0A2Canada Petroleum and Mining engineering School of Applied Science&TechnologyShahjalal University of Science and TechnologySylhet3114Bangladesh

Surfactant foam stability gets a lot of interest while posing a significant obstacle to many industrial *** of the viable solutions for addressing gas mobility concerns and boosting reservoir fluid sweep efficiency during solvent-based enhanced heavy oil recovery processes is foam *** synergistic effect of nanoparticles and surfactants in a porous reservoir media can help create a more durable and sturdier *** study aims to see how well a combination of the nanoparticles(NPs)and surfactant can generate foam for controlling gas mobility and improving oil *** research looked at the effects of silicon and aluminum oxide nanoparticles on the bulk and dynamic stability of sodium dodecyl surfactant(SDS)-foam in the presence and absence of *** foam height,liquid drainage,half-decay life,nanoparticle deposition,and bubble size distribution of the generated foams with time were used to assess static foam stability in the bulk phase,while dynamic stability was studied in the *** understand the processes of foam stabilization by nanoparticles,the microscopic images of foam and the shape of bubbles were *** nanoparticles were applied in foamability testing in bulk and dynamic phase,the foam generation and stability were improved by 23%and 17%,*** comparison to surfactant alone,adding nanoparticles to surfactant solutions leads to a more significant pressure drop of 17.34 psi for SiO_(2)and 14.86 psi for Al_(2)O_(3)NPs and,as a result,a higher reduction in gas mobility which ultimately assists in enhancing oil recovery.

关键词： Foam stability Nanoparticles Surfactant Foam decay Pressure drop Enhanced oil recovery Etc

Adsorption of arsenate and arsenite from aqueous solutions by cerium-loaded cation exchange resin

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Journal of Rare Earths 2012年第6期30卷 563-572页

作者：何宗良田森林宁平 faculty of Environmental science and engineering Kunming University of Science and Technology

The removal of arsenic from water and wastewater is obligatory. Resin is one of the most effective adsorbents for the removal of arsenic. In order to improve the adsorption capacity of resin, a new cerium-loaded cation exchange resin arsenic adsorbent was prepared by impregnating cerium into the cation exchange resin. Batch adsorption experiments under various conditions, such as time, temperature, pH and with coexisting ions were carried out to evaluate the adsorption characteristics of cerium-loaded resin in the removal of As（V） and As（III） from aqueous solutions. The results showed that the adsorption kinetics of As（V） and As（III） obeyed a pseudo second-order kinetic model and the adsorption rate constants were 0.3159 and 0.5215 ***-1-min-1, respectively. The adsorption of As（V） followed the Freundlich adsorption isotherm model and the adsorption isotherm data for As（III） fitted well to the Langmuir equation model. The adsorption capacities were 1.0278 mg/g for As（V） and 2.5297 mg/g for As（Ill）. Both the adsorption of As（V） and As（Ill） were found to be pH sensitive and the optimum pH was found to be 5-6. Except for the phosphate ion, the coexisting anionics, such as nitrate, chlorate, sulphate and carbonate, showed no remarkable effect on As（V） and As（ill） adsorption. The desorption and regeneration study showed that the adsorption capacity of ce-loaded resin for As（V） and As（Ill） could be restored to 97.80% and 69.61%, respectively, using 0.5 moFL sodium hydroxide solution.

关键词： arsenic pollution cerium resin arsenate arsenite adsorption rare earths

Effect of zinc and cerium addition on property of copper-based adsorbents for phosphine adsorption

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Journal of Rare Earths 2010年第4期28卷 581-586页

作者：宁平易红宏余琼粉唐晓龙杨丽萍叶智青 faculty of Environmental science and engineering Kunming University of Science & Technology

A series of copper-based activated carbon (Ac) adsorbents were prepared in order to investigate the effect of Zn, ce addition on cu-based Ac adsorbent for phosphine (PH3) adsorption removal from yellow phosphorous tail gas. N2 adsorption isotherm and X-ray diffrac-tion (XRD) results suggested that the addition of Zn could increase the adsorbent ultramicropores, decrease the adsorbent supermicropores and the adsorbent average pore diameter. Therefore it enhanced the PH3 adsorption capacity. Appropriate amoun...

关键词： cu-based adsorbent zinc cerium phosphine adsorption removal rare earths

Influence of HfO2 alloying effect on microstructure and thermal conductivity of HoTaO4 ceramics

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Journal of Advanced ceramics 2019年第4期8卷 537-544页

作者： Lin cHEN Jing FENG faculty of Material science and engineering Kunming University of Science and Technology

HfO2 alloying effect has been applied to optimize thermal insulation performance of HoTaO4 ceramics.X-ray diffraction,Raman spectroscopy,and X-ray photoelectron spectroscopy are employed to decide the crystal *** electronic microscopy is utilized to detect the influence of HfO2 alloying effect on *** paper indicates that the same numbers of Ta5+and Ho3+ions of HoTaO4 are substituted by Hf4+cations,and it is defined as alloying *** crystal structural transition is introduced by HfO2 alloying effect,and circular pores are produced in ***2 alloying effect is efficient in decreasing thermal conductivity of HoTaO4 and it is contributed to the differences of ionic radius and atomic weight between Hf4+ions and host cations(Ta5+and Ho3+).The least experimental thermal conductivity is 0.8 W·K–1·m–1 at 900℃,which is detected in 6 and 9 mol%-HfO2 HoTaO4 *** results imply that HfO2–HoTaO4 ceramics are promising thermal barrier coatings(TBcs)due to their extraordinary thermal insulation performance.

关键词： thermal barrier coating(TBc) thermal conductivity rare earth tantalates microstructure alloying effect optical property