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Mixed convection flow in vertical channel with boundary conditions of third kind in presence of heat source/sink

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Applied Mathematics and Mechanics(English Edition) 2012年第8期33卷 1015-1034页

作者： j.C.UMAVATHI j.PRATHAP KUMAR jAWERIYA sultana Department of Mathematics Gulbarga UniversityGulbarga 585106KarnatakaIndia

The effects of viscous dissipation and heat source/sink on fully developed mixed convection for the laminar flow in a parallel-plate vertical channel are investigated. The plate exchanges heat with an external fluid. Both conditions of equal and different reference temperatures of the external fluid are considered. First, the simple cases of the negligible Brinkman number or the negligible Grashof number are solved analytically. Then, the combined effects of buoyancy forces and viscous dissipation in the presence of heat source/sink are analyzed by a perturbation series method valid for small values of the perturbation parameter. To relax the conditions on the perturbation parameter, the velocity and temperature fields are solved by using the Runge-Kutta fourth-order method with the shooting technique. The velocity, temperature, skin friction, and Nusselt num- bers at the plates are discussed numerically and presented through graphs.

关键词： mixed convection viscous fluid perturbation method Runge-Kuttashooting method heat source/sink

Non-axisymmetric Homann MHD stagnation point flow of Al2O3-Cu/water hybrid nanofluid with shape factor impact

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Applied Mathematics and Mechanics(English Edition) 2020年第8期41卷 1125-1138页

作者： M.KHAN j.AHMED F.sultana M.SARFRAZ Department of Mathematics Quaid-i-Azam UniversityIslamabad 44000Pakistan Department of Basic Sciences University of Engineering and TechnologyTaxila 47050Pakistan

The heat transfer of Homann flow in the stagnation region of the Al2 O3-Cu/water hybrid nanofluid is investigated by adopting the Tiwari-Das model over a cylindrical *** effects of the nanoparticle shape,the viscous dissipation,and the nonlinear radiation are *** governing equations are obtained by using similarity transformations,and the numerical outcomes for the flow and the temperature field are noted by bvp4 c on *** numerical solutions of the flow field are compared with the asymptotic behaviors of large shear-to-strain-rate *** effects of variations of parameters involved are inspected for both nanofluid and hybrid nanofluid flows,temperature profiles,local Nusselt numbers,and skin *** is concluded that the velocity and temperature fields in the hybrid nanophase function more rapidly than those in the nanofluid phase.

关键词： cylindrical disk hybrid nanofluid magnetic field non-linear thermal radiation stagnation point flow viscous dissipation

Self-assembled V2O5 interconnected microspheres produced in a fish-water electrolyte medium as a high- performance lithium-ion-battery cathode

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Nano Research 2015年第11期8卷 3591-3603页

作者： Md Mokhlesur Rahman Abu Z. Sadek Irin sultana Mateti Srikanth Xiujuan j. Dai Matthew R. Field Dougal G. McCulloch Sri Balaji Ponraj Ying Chen Institute for Frontier Materials Deakin University Waurn Ponds VIC 3216 Australia Melbourne Centre for Nanofabrication 151 Wellington Rd Clayton VIC 3168 Australia School of Applied Sciences Applied Physics RMIT University Melbourne VIC 3001 Australia

Interconnected microspheres of V2Os composed of ultra-long nanobelts are synthesized in an environmental friendly way by adopting a conventional anodization process combined with annealing. The synthesis process is simple and low-cost because it does not require any additional chemicals or reagents. Commercial fish-water is used as an electrolyte medium to anodize vanadium foil for the first time. Electron microscopy investigation reveals that each belt consists of numerous nanofibers with free space between them. Therefore, this novel nanostructure demonstrates many outstanding features during electrochemical operation. This structure prevents self-aggregation of active materials and fully utilizes the advantage of active materials by maintaining a large effective contact area between active materials, conductive additives, and electrolyte, which is a key challenge for most nanomaterials. The electrodes exhibit promising electrochemical performance with a stable discharge capacity of 227 mAh·g^-1 at 1C after 200 cycles. The rate capability of the electrode is outstanding, and the obtained capacity is as high as 278 at 0.5C, 259 at 1C, 240 at 2C, 206 at 5C, and 166 mAh·g^-1 at 10C. Overall this novel structure could be one of the most favorable nanostructures of vanadium oxide-based cathodes for Li-ion batteries.

关键词： self-assembly interconnected microspheres fish-water electrolyte V2O5 cathode lithium-ion batteries

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单层金刚石工具螺旋钻削复合材料的性能比较

金刚石与磨料磨具工程 2023年第3期43卷 273-284页

作者： sultana Ireen 史忠德 ATTIA Helmi THOMSON Vincent 麦吉尔大学加拿大魁北克蒙特利尔H3A0C3 加拿大国家研究院航空航天研究中心航空航天制造技术中心加拿大魁北克蒙特利尔H3T1J4

使用不同形状、不同磨粒尺寸的单层金刚石工具以螺旋钻孔方式加工多向碳纤维-环氧树脂层压板,比较各工具的加工性能。在复合材料上钻孔时,和传统钻削相比,螺旋钻孔是更先进和完善的方法。选择7种不同工具开展性能试验,研究金刚石磨粒尺... 详细信息

使用不同形状、不同磨粒尺寸的单层金刚石工具以螺旋钻孔方式加工多向碳纤维-环氧树脂层压板,比较各工具的加工性能。在复合材料上钻孔时,和传统钻削相比,螺旋钻孔是更先进和完善的方法。选择7种不同工具开展性能试验,研究金刚石磨粒尺寸、刀具槽口类型和末端几何形状对钻进力、温度、钻进缺陷和表面完整性的影响。结果发现高速旋转钻削可以显著降低钻削力。使用磨粒尺寸更小的工具进行加工,可以改善钻孔表面粗糙度,但是其钻削力更大、钻削温度更高。带有槽口的工具可以减轻工具表面堵塞。和平直末端或无槽口的工具相比,球形末端的工具性能更好。

关键词：螺旋钻孔 CFRP 单层金刚石工具钻削力温度表面完整性

Selective C3-alkenylation of oxindole with aldehydes using heterogeneous CeO2 catalyst

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Chinese journal of Catalysis 2020年第6期41卷 970-976页

作者： MdNurnobi Rashed Abeda sultana Touchy Chandan Chaudhari jaewan jeon S.M.A.Hakim Siddiki Takashi Toyao Ken-ichi Shimizu Institute for catalysis hokkaido universityN-21W-10sapporo 001-0021japan Department of chemical systems engineering graduate school of engineeringnagoya universitynagoya 464-8603japan Elements strategy initiative for catalysts and batteries kyoto universitykatsurakyoto 615-8520japan

We report herein that a commercially available CeO2 is an active and reusable catalyst for the C3-selective alkenylation of oxindole with aldehydes under solvent-free conditions. This catalytic method is generally applicable to different aromatic and aliphatic aldehydes, giving 3-alkyledene-oxindoles in high yields(87%–99%) and high stereoselectivities(79%–93% to E-isomers). This is the first example of the catalytic synthesis of 3-alkenyl-oxindoles from oxindole and various aliphatic aldehydes. The Lewis acid-base interaction between Lewis acid sites on CeO2 and benzaldehyde was studied by in situ IR. The structure-activity relationship study using CeO2 catalysts with different sizes suggests that defect-free CeO2 surface is the active site for this reaction.

关键词： Oxindole Aldehyde Aldol condensation C3-alkenylation CeO2 catalyst

Effect of Vapour Absorption Enhancement in Solar-Heat Driven Air-Conditioning System

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Effect of Vapour Absorption Enhancement in Solar-Heat Driven...

State of Energy Consumption and CO_2 Emission in Bangladesh

作者： Papia sultana N.E.Wijeysundera j.C.Ho C.Yap T.K.Chang School of Engineering Republic PolytechnicSingapore Mechanical Engineering Department National University of Singapore

The solar-heat driven air-conditioning system has strong potential for significant primary energy *** most applications,the system involves Li-Br-water absorption chillers,which are suitable for large building *** absorption chillers to be used in small residential buildings,the reduction of the chiller system footprint is *** the present study focus has been given to design a vapour-absorption cooling system with improved transport phenomena using film-inversion *** film-inverting absorber has resulted in the enhancement of vapour absorption rate by 83-95 percent more than a conventional falling film-tubular absorber based on numerical simulation *** proposed design has the potential to increase Coefficient of Performance(COP) of a single-effect vapour absorption system 160% higher than that of a conventional vapour-absorption *** could also reduce the foot-print of the entire vapour absorption system especially for low-grade-heat driven *** least 10°C temperature reduction has been achieved in maintaining the same condensing ***,a smaller area is needed to harvest hot water for a solar-heat driven air-conditioning *** there has been at least 65% reduction of the collector area needed per k W cooling energy.

关键词： Coefficient of Performance(COP) film-inverting solar-heat-driven vapour absorption

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AMBIO－人类环境杂志 2006年第2期35卷 86-88页

作者： Abul K. Azad S.W. Nashreen j. sultana 丁莉（译）库尔纳(Khulna)大学库尔纳工程和技术大学(KUET)物理系

二氧化碳（CO2）是大气中的最重要气体之一而且对于维持地球上的生命是必须的。它还被认为是导致全球变暖和气候变化的一种主要温室气体。本文对孟加扭国的能源消耗进行了分析并且估计了1977～1995年间化石燃料（煤炭、天然气、石油产... 详细信息

二氧化碳（CO2）是大气中的最重要气体之一而且对于维持地球上的生命是必须的。它还被认为是导致全球变暖和气候变化的一种主要温室气体。本文对孟加扭国的能源消耗进行了分析并且估计了1977～1995年间化石燃料（煤炭、天然气、石油产品）燃烧产生的CO2排放量。我们采用国际气候变化小组计算国家温室气体总量的方法来估算CO2排放量。对能源数据的分析表明孟加扛国化石燃料消耗每年增长超过5％。在能源消耗总量中，天然气的比率正在增加，而石油产品和煤炭的比率正在降低。孟加拉国主要化石燃料排放的CO2总量1977年为5072（Gg），而1995年为14423Gg。1977～1995年间从石油产品、天然气和煤炭中排放的CO2总量分别为83026Gg（CO2排放量的50％），72541Gg（CO2排放量的44％）和9545Gg（CO2排放量的6％）。由此产生了到2070年CO2排放量的趋势预测。到2070年，总的CO2排放估算值为293260Gg，现有增长率为每年6．34％。化石燃料的CO2排放量正在逐渐增加。石油产品产生了大部分的CO2排放，虽然天然气的使用迅速增加，其CO2排放对CO2排放总量的比例仍然低于石油产品。煤炭的使用预计将会逐渐减少，其CO2排放量也将逐渐降低。

关键词： CO2排放量能源消耗孟加拉国石油产品化石燃料温室气体气候变化天然气二氧化碳全球变暖

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肺结核应用气腹疗法时支气管造影分析

中华结核和呼吸杂志 1958年第1期06卷 84-84页

作者： H. M. sultana, Brit. j. Tuberc. 钱元福(摘译)