检索结果-南通市图书馆

Communications in Theoretical Physics 2018年第4期69卷 449-460页

作者： Tariq Javed B.Ahmed m.sajid Department of mathematics and Statistics International Islamic University

The current study focuses on the numerical investigation of the mixed convective peristaltic mechanism through a vertical tube for non-zero Reynolds and wave number. In the set of constitutional equations, energy equation contains the term representing heat generation parameter. The problem is formulated by dropping the assumption of lubrication theory that turns the model mathematically into a system of the nonlinear partial differential equations. The results of the long wavelength in a creeping flow are deduced from the present analysis. Thus, the current study explores the neglected features of peristaltic heat flow in the mixed convective model by considering moderate values of Reynolds and wave numbers. The finite element based on Galerkin's weighted residual scheme is applied to solve the governing equations. The computed solution is presented in the form of contours of streamlines and isothermal lines, velocity and temperature profiles for variation of different involved parameters. The investigation shows that the strength of circulation for stream function increases by increasing the wave number and Reynolds number. Symmetric isotherms are reported for small values of time-mean flow. Linear behavior of pressure is noticed by vanishing inertial forces while the increase in pressure is observed by amplifying the Reynolds number.

关键词： mixed convection peristaltic flow moderate Reynolds number finite element method

Axisymmetric Stagnation-Point Flow with a General Slip Boundary Condition over a Lubricated Surface

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2012年第2期29卷 126-129页

作者： m.sajid K.mahmood Z.Abbas The Abdus Salam International Centre for Theoretical Physics Strada Costiera 1134014TriesteItaly Department of mathematics Riphah International UniversityIslamabad 44000Pakistan Department of mathematics The Islamia University of BahawalpurBahawalpurPakistan

We investigate the axisymmetric stagnation-point flow of a viscous fluid over a lubricated surface by imposing a generalized slip condition at the fluid-fluid *** power law non-Newtonian fluid is considered as a *** lubrication layer is thin and assumed to have a variable *** transformed nonlinear ordinary differential equation governing the flow is linearized using *** method of superposi-tion is adopted to convert the boundary value problem into an initial value problem and the solution is obtained numerically by using the fourth-order Runge-Kutta *** results are discussed to see the influence of pertinent *** limiting cases of Navier and no-slip boundary conditions are obtained as the special cases and found to be in excellent agreement with the existing results in the literature.

关键词： boundary ordinary assumed

Series Solution for Rotating Flow of an Upper Convected maxwell Fluid over a Stretching Sheet

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2011年第10期56卷 740-744页

作者： m.sajid Z.Iqbal T.Hayat S.Obaidat Theoretical Plasma Physics Division PINSTECHP.O.Nilore Islamabad 44000Pakistan Department of mathematics Quaid-i-Azam University 45320 Islamabad 44000Pakistan Department of mathematics College of ScienceKing Saud UniversityP.O.Box.2455Riyadh 11451Saudi Arabia

The equations for two-dimensional flow of an upper convected maxwell （UCm） fluid in a rotating frame are modeled. The resulting equations are first simplified by a boundary layer approach and then solved by a homotopy analysis method （HAm）. Convergence of series solution is discussed through residual error curves. The results of the influence of viscoelastic and rotation parameters are plotted and discussed.

关键词： rotating flow stretching sheet UCm fluid HAm solution residual error

Alternative Strategy for Development of Dielectric Calcium Copper Titanate‑Based Electrolytes for Low‑Temperature Solid Oxide Fuel Cells

在线全文

学校读者我要写书评

暂无评论

Nano-micro Letters 2025年第1期17卷 310-332页

作者： sajid Rauf muhammad Bilal Hanif Zuhra Tayyab matej Veis mAKYousaf Shah Naveed mushtaq Dmitry medvedev Yibin Tian Chen Xia martin motola Bin Zhu College of mechatronics and Control Engineering Shenzhen UniversityShenzhen 518060People’s Republic of China Department of Inorganic Chemistry Faculty of Natural SciencesComenius University BratislavaIlkovicova684215 BratislavaSlovakia Energy Storage Joint Research Center School of Energy and EnvironmentSoutheast UniversityNanjing 210096People’s Republic of China Hydrogen Energy Laboratory Ural Federal University620002 EkaterinburgRussia Laboratory of Electrochemical Devices Based on Solid Oxide Proton Electrolytes Institute of High Temperature Electrochemistry620066 EkaterinburgRussia School of microelectronics Hubei UniversityWuhan 430062People’s Republic of China

The development of low-temperature solid oxide fuel cells(LT-SOFCs)is of significant importance for realizing the widespread application of *** has stimulated a substantial materials research effort in developing high oxide-ion conductivity in the electrolyte layer of *** this context,for the first time,a dielectric material,CaCu_(3)Ti_(4)O_(12)(CCTO)is designed for LT-SOFCs electrolyte application in this *** individual CCTO and its heterostructure materials with a p-type Ni_(0.8)Co_(0.15)Al_(0.05)LiO_(2−δ)(NCAL)semiconductor are evaluated as alternative electrolytes in LT-SOFC at 450–550℃.The single cell with the individual CCTO electrolyte exhibits a power output of approximately 263 mW cm^(-2) and an open-circuit voltage(OCV)of 0.95 V at 550℃,while the cell with the CCTO–NCAL heterostructure electrolyte capably delivers an improved power output of approximately 605 mW cm^(-2) along with a higher OCV over 1.0 V,which indicates the introduction of high hole-conducting NCAL into the CCTO could enhance the cell performance rather than inducing any potential short-circuiting *** is found that these promising outcomes are due to the interplay of the dielectric material,its structure,and overall properties that led to improve electrochemical mechanism in CCTO–***,density functional theory calculations provide the detailed information about the electronic and structural properties of the CCTO and NCAL and their heterostructure CCTO–*** study thus provides a new approach for developing new advanced electrolytes for LT-SOFCs.

关键词： LT-SOFCs Dielectric CaCu_(3)Ti_(4)O_(12) Semiconductor Ni_(0.8)Co_(0.15)Al_(0.05)LiO_(2−δ) Ionic conductivity Heterostructure electrolyte

Petrogenesis of Granites from the Utla Area of Gadoon, North-West Pakistan: Implications from Petrography and Geochemistry

在线全文

学校读者我要写书评

暂无评论

Journal of Earth Science 2014年第3期25卷 445-459页

作者： muhammad sajid mohammad Arif m Tahir Shah Department of Geology University of Peshawar National Center of Excellence in Geology University of Peshawar

The granitic rocks around the Utla area（Gadoon）, north western, Pakistan are studied in terms of their petrographic features and geochemical characteristics. Although predominantly mega-porphyritic, some of the Utla granites are massive and display fine-grained equi-granular texture. Some of the mega-porphyritic varieties exhibit foliation and seem to be restricted to shear zones. In addition to being distributed largely as phenocrysts, all the essential minerals（plagioclase, perthitic alkali feldspar and quartz） also constitute the groundmass. The studied samples also contain minor to accessory amounts of tourmaline, muscovite and biotite and accessory to trace amounts of apatite, andalusite, garnet, zircon, monazite, epidote and sphene. A detailed geochemical investigation reveals a calc-alkaline and peraluminous character of the Utla granites. The peraluminous character and total lack of hornblende designate their S-type character while a volcanic arc or syn-collisional tectonic setting for their emplacement is indicated by discrimination diagrams. Further examination shows that the melt parental to the Utla granite was derived from a plagioclase-poor, clay-rich rock, i.e., pelite. The petrogenetically significant petrographic and geochemical features of the Utla granite show greater similarity with the mansehra than the Ambela granites. These include（i） the predominantly megaporphyritic texture,（ii） the presence of andalusite and tourmaline,（iii） the calc-alkaline geochemical signature and（iv） an indication of similar melt source rock character.

关键词： petrography geochemistry granite Utla Pakistan.

Novel hole transport layer of nickel oxide composite with carbon for high-performance perovskite solar cells

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2018年第1期27卷 80-86页

作者： sajid A m Elseman 纪军窦尚轶黄浩崔鹏卫东李美成 State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources School of Renewable EnergyNorth China Electric Power University Electronic & magnetic materials Department Advanced Materials Division Central Metallurgical Research and Development Institute (CMRDI)

A depth behavioral understanding for each layer in perovskite solar cells （PSCs） and their inter[acial interactions as a whole has been emerged for further enhancement in power conversion efficiency （PCE）. Herein, NiO@Carbon was not only simulated as a hole transport layer but also as a counter electrode at the same time in the planar heterojunction based PSCs with the program wxAmPS （analysis of microelectronic and photonic structures）-lD. Simulation results revealed a high dependence of PCE on the effect of band offset between hole transport material （HTm） and perovskite layers. meanwhile, the valence band offset （AEv） of NiO-HTm was optimized to be -0.1 to -0.3 eV lower than that of the perovskite layer. Additionally, a barrier cliff was identified to significantly influence the hole extraction at the HTm/absorber interface. Conversely, the AEv between the active material and NiO@Carbon-HTm was derived to be -0.15 to 0.15 eV with an enhanced efficiency from 15% to 16%.

关键词： hole transporting materials counter electrode perovskite solar cells simulation

An Analysis of Peristaltic Flow of a micropolar Fluid in a Curved Channel

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2011年第1期28卷 138-141页

作者： N. Ali m. sajid T. ,laved Z. Abbas Department of mathematics International Islamic University Islamabad Paksitan Theoretical Plasma Physics Division PINSTECH P.O. Nilore Islamabad Pakistan

We analyze the two-dimensional peristaltic flow of a micropolar fluid in a curved channel. Long wavelength and low Reynolds number assumptions are used in deriving the governing equations. A shooting method with fourth-order Runge-Kutta algorithm is employed to solve the equations. The influence of dimensionless curvature radius on pumping and trapping phenomena is discussed with the help of graphical results. It is seen that the pressure rise per wavelength in the pumping region increases with an increase in the curvature of the channel. moreover the symmetry of the trapped bolus destroys in going from strmg＇ht to curved channel.

关键词： Fluid dynamics

Stretching a Curved Surface in a Viscous Fluid

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics Letters 2010年第2期27卷 149-152页

作者： m. sajid N. Ali T. Javed Z. Abbas Theoretical Plasma Physics Division PINSTECH P.O. Nilore Islamabad 44000 Pakistan Faculty of Basic and Applied Sciences International Islamic University Islamabad 44000 Pakistan

This work is concerned with the viscous flow due to a curved stretching sheet. The similarity solution of the problem is obtained numerically by a shooting method using the Runge-Kutta algorithm. The physical quantities of interest like the fluid velocity and skin friction coefficient are obtained and discussed under the influence of dimensionless curvature. It is evident from the results that dimensionless curvature causes an increase in boundary layer thickness and a decrease in the skin friction coefficient.

关键词： Fluid dynamics mathematical physics

An Animated GIF Steganography Using Variable Block Partition Scheme

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computer Systems Science & Engineering 2022年第12期43卷 897-914页

作者： maram Abdullah m.Alyahya Arshiya S.Ansari mohammad sajid mohammadi Department of Information Technology College of Computer and Information SciencesMajmaah UniversityAl-Majmaah11952Saudi Arabia Department of Information Technology College of ComputerQassim UniversityBuraydah51452Saudi Arabia

The paper presents a novel Graphics Interchange Format (GIF) Steganography system. The algorithm uses an animated (GIF) file format video to applyon, a secured and variable image partition scheme for data embedding. The secretdata could be any character text, any image, an audio file, or a video file;that isconverted in the form of bits. The proposed method uses a variable partitionscheme structure for data embedding in the (GIF) file format video. The algorithmestimates the capacity of the cover (GIF) image frames to embed data bits. Ourmethod built variable partition blocks in an empty frame separately and incorporate it with randomly selected (GIF) frames. This way the (GIF) frame is dividedinto variable block same as in the empty frame. Then algorithm embeds secretdata on appropriate pixel of the (GIF) frame. Each selected partition block for dataembedding, can store a different number of data bits based on block size. Intruders could never come to know exact position of the secrete data in this stegoframe. All the (GIF) frames are rebuild to make animated stego (GIF) *** performance of the proposed (GIF) algorithm has experimented andevaluated based on different input parameters, like mean Square Error (mSE)and Peak Signal-to-Noise Ratio (PSNR) values. The results are compared withsome existing methods and found that our method has promising results.

关键词： (GIF)Steganography frame partition variable data insertion data encapsulation

Proton transport controlled at surface layer of CeO_(2) by gradient-doping with a built-in-field effect

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Rare Earths 2023年第12期41卷 2025-2032,I0008页

作者： Yuzheng Lu Naveed mushtaq m.A.K Yousaf Shah sajid Rauf Chen Xia Bin Zhu School of Electronic Engineering Nanjing Xiaozhuang UniversityNanjing21171China School of Physics Electronics and Intelligent ManufacturingHuaihua UniversityHuaihua418008China Jiangsu Provincial Key Laboratory of Solar Energy Science and Technology/Energy Storage Joint Research Center School of Energy and EnvironmentSoutheast UniversityNanjing210096China College of Electronics and Information Engineering Shenzhen UniversityShenzhen58000China Faculty of Physics and Electronic Science Hubei UniversityWuhan430062China

Ceramic fuel cells hold an important position for the sustainable energy future using renewable energy sources with high *** design and synthesis of active materials,interface engineering and having capability of low operating temperature is considered as an important factor to further increase the power output and stability of ceramic fuel cell devices.A novel methodology has vital importance to develop new functionalities of existing materials by introducing new different *** built-in electric field(BIEF) is one of the most recently used approaches to improve charge transfer and ionic conductivity of solid oxide ***,we demonstrate gradient doping strategy in CeO_(2)-δstructure to produce BIEF effect and to modulate the proton transport effectively at the surface layer rather than bulk *** inclusions of La and Sr metal ions at the surface and Co-metal ions into bulk-layer of CeO_(2)form the gradiently doped *** gradient doping into CeO_(2)highly improves the proton transport properties through the surface layer by modifying the energy ***,unbalanced charge distribution due to gradient doping produces built-in electric-field to provide extra driving force for protons transport through surface *** acquired gradiently doped fluorite structure exhibits remarkable proton conductivity of>0.2 S/cm,as a result ceramic fuel cell shows power output of>1000 mW/cm2while operating at 500℃.This unique work highlights the critical role of gradiently doped electrolyte in electrochemical conversion energy devices and offers new understanding and practices for sustainable energy future.

关键词： La_(0.20)Sr_(0.05)Ce_(0.65)Co_(0.1)0_(2-δ)(LSCC) Gradient doping Fast protonic transport High grain boundary conduction Built-in electric field Rare earths