检索结果-南通市图书馆

The Analysis of Wall Shear Stress Modulated by Acute Exercise in the Human Common Carotid Artery with an Elastic Tube Model

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2018年第8期116卷 127-147页

作者： Yanxia Wang Yu Wang Siqi Li aziz ur rehman aziz Shutian Liu Kairong Qin Department of Engineering Mechanics State Key Laboratory of Structural Analysis for Industrial EquipmentDalian University of TechnologyNo.2Linggong RoadDalian116024China. School of Optoelectronic Engineering and Instrumentation Science Dalian University of TechnologyNo.2Linggong RoadDalian116024China. School of Biomedical Engineering Dalian University of TechnologyNo.2Linggong RoadDalian116024China.

Assessment of the magnitude and pattern of wall shear stress(WSS)in vivo is the prerequisite for studying the quantitative relationship between exercise-induced WSS and arterial endothelial *** the previous studies,the calculation of the WSS modulated by exercise training was primarily based upon the rigid tube model,which did not take non-linear effects of vessel elastic deformation into *** this study,with an elastic tube model,we estimated the effect of a bout of 30-minute acute cycling exercise on the WSS and the flow rate in the common carotid artery according to the measured inner diameter,center-line blood flow velocity,heart rates and the brachial blood pressures before and after exercise ***,the roles of exerciseinduced arterial diameter and blood flow rate in the change of WSS were also *** numerical results demonstrate that acute exercise significantly increases the magnitudes of blood flow rate and ***,the vessel elastic deformation is a non-negligible factor in the calculation of the WSS induced by exercise,which generates greater effects on the minimum WSS than the maximum ***,the contributions of exercise-induced variations in blood flow rate and diameter are almost identical in the change of the mean WSS.

关键词： Acute cycling exercise blood flow wall shear stress common carotid artery elastic tube model rigid tube model

Dynamical Analysis of Radiation and Heat Transfer on MHD Second Grade 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

Computer Modeling in Engineering & Sciences 2021年第11期129卷 689-703页

作者： aziz-ur-rehman Muhammad Bilal Riaz Syed Tauseef Saeed Shaowen Yao Department of Mathematics University of Management and TechnologyLahore54770Pakistan Institute for Groundwater Studies(IGS) University of the Free StateBloemfontein9301South Africa Department of Science&Humanities National University of Computer and Emerging SciencesLahore54000Pakistan School of Mathematics and Information Science Henan Polytechnic UniversityJiaozuo454000China

Convective flow is a self-sustained flow with the effect of the temperature *** density is non-uniform due to the variation of *** effect of the magnetic flux plays a major role in convective *** process of heat transfer is accompanied by a mass transfer process;for instance,condensation,evaporation,and chemical *** to the applications of the heat and mass transfer combined effects in a different field,the main aim of this paper is to do a comprehensive analysis of heat and mass transfer of MHD unsteady second-grade fluid in the presence of ramped boundary conditions near a porous *** dynamical analysis of heat transfer is based on classical differentiation with no memory *** non-dimensional form of the governing equations of the model is *** are solved by the classical integral(Laplace)transform technique/method with the convolution theorem and closed-form solutions are attained for temperature,concentration,and *** physical aspects of distinct parameters are discussed via graph to see the influence on the fluid concentration,velocity,and *** results suggest that the velocity profile decrease by increasing the Prandtl *** existence of a Prandtl number may reflect the control of the thickness of momentum and enlargement of thermal ***,to validate our results,some results are recovered from the literature.

关键词： Heat transfer magnetic effect ramped conditions porous medium Laplace transform thermal radiation

Impact of Tillage and Herbicides on Weed Density, Yield and Quality of Cotton in Wheat Based Cropping System

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 Integrative Agriculture 2013年第9期12卷 1568-1579页

作者： Khalid Usman Niamatullah Khan Muhammad Umar Khan aziz ur rehman Said Ghulam Department of Agronomy Faculty of AgricultureGomal University Department of Agriculture Chemistry Faculty of AgricultureGomal University Department of Soil & Environmental Sciences Faculty of AgricultureGomal University

Conservation tillage may improve yield of cotton in addition to improvement in soil quality if practiced for longer period. However, the practice may not be productive in short-term particularly when severe weeds are infesting the crops such as Cynodon dactylon, Conyza canadensis, Tribulus terrestris, and Cyperus rotundus, etc. Recent studies indicate that conventional tillage （CT） is more productive than zero tillage （ZT）/reduced tillage （RT）. Performance of cotton under three tillage systems, viz., ZT, RT and CT; and five herbicides, i.e., haloxyfop-R-methyl 10.8 EC （108 g a.i. ha^-1）, lactofen 24 EC （168 g a.i. ha^-1）, haloxyfop 10.8 EC ＋ lactofen 24 EC, hand weeding, and weedy check were evaluated during 2010-2011 at Gomal University, ***, Pakistan, to explore the best management option for effective weed control, enhanced yield and quality of cotton grown after wheat. The results revealed that hand weeding and Haloxyfop as post emergence alone or in combination with Lactofen reduced weed density to the minimum irrespective of the tillage systems. Excessive rainfall and cooler temperature limited cotton growth and yield in 2010. The adverse weather conditions had more adverse effect on boll weight under ZT and RT than CT. Haloxyfop ＋ lactofen produced higher seed cotton yield in RT than ZT, however, it could not exceed CT. Broad-spectrum herbicides x CT produced the highest number of bolls/plant, boll weight and seed cotton yield. Fiber quality and net returns were also the highest in broad-spectrum herbicides x CT. In conclusion, broad-spectrum herbicides under CT were more productive in wheat based cropping system on silty clay soil of ***.

关键词： tillage herbicide cotton seed cotton yield weed density net return

维普期刊数据库

Numerical Study of Computer Virus Reaction Diffusion Epidemic Model

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2021年第3期66卷 3183-3194页

作者： Umbreen Fatima Dumitru Baleanu Nauman Ahmed Shumaila Azam Ali Raza Muhammad Rafiq Muhammad aziz-ur rehman Department of Computer Science The University of LahoreLahorePakistan Department of Mathematics Cankaya UniversityAnkaraTurkey Institute of Space Sciences Magurele-BucharestRomania Department of Medical Research China Medical University HospitalChina Medical UniversityTaichungTaiwan Department of Mathematics and Statistics The University of LahoreLahorePakistan Department of Mathematics National College of Business Administration and Economics LahoreLahorePakistan Faculty of Engineering University of Central PunjabLahorePakistan Department of Mathematics University of Management and TechnologyLahorePakistan

Reaction–diffusion systems are mathematical models which link to several physical *** most common is the change in space and time of the meditation of one or more ***–diffusion modeling is a substantial role in the modeling of computer propagation like infectious *** investigated the transmission dynamics of the computer virus in which connected to each other through network *** current study devoted to the structure-preserving analysis of the computer propagation *** manuscript is devoted to finding the numerical investigation of the reaction–diffusion computer virus epidemic model with the help of a reliable *** designed technique is finite difference scheme which sustains the important physical behavior of continuous model like the positivity of the dependent variables,the stability of the *** theoretical analysis of the proposed method like the positivity of the approximation,stability,and consistency is discussed in detail.A numerical example of simulations yields the authentication of the theoretical results of the designed technique.

关键词： Computer virus dynamics reaction-diffusion system positive solution simulations

Structure Preserving Algorithm for Fractional Order Mathematical Model of COVID-19

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2022年第5期71卷 2141-2157页

作者： Zafar Iqbal Muhammad aziz-ur rehman Nauman Ahmed Ali Raza Muhammad Rafiq Ilyas Khan Kottakkaran Sooppy Nisar Department of Mathematics University of Management and TechnologyLahorePakistan Department of Mathematics and Statistics The University of LahoreLahorePakistan Stochastic Analysis&Optimization Research Group Department of MathematicsAir UniversityIslamabad44000Pakistan Department of Mathematics National College of Business Administration and EconomicsLahorePakistan Department of Mathematics Faculty of SciencesUniversity of Central PunjabLahore54500Pakistan Faculty of Mathematics and Statistics Ton Duc Thang UniversityHo Chi Minh City72915Vietnam Department of Mathematics College of Arts and Science at Wadi AldawaserPrince Sattam Bin Abdulaziz UniversityAlkharj11991Kingdom of Saudi Arabia

In this article,a brief biological structure and some basic properties of COVID-19 are described.A classical integer order model is modified and converted into a fractional order model withξas order of the fractional ***,a valued structure preserving the numerical design,coined as Grunwald–Letnikov non-standard finite difference scheme,is developed for the fractional COVID-19 *** into account the importance of the positivity and boundedness of the state variables,some productive results have been proved to ensure these essential *** of the model at a corona free and a corona existing equilibrium points is investigated on the basis of Eigen *** Routh–Hurwitz criterion is applied for the local stability *** appropriate example with fitted and estimated set of parametric values is presented for the *** solutions are displayed for the chosen values ofξ(fractional order of the derivatives).The role of quarantined policy is also determined gradually to highlight its significance and relevancy in controlling infectious *** the end,outcomes of the study are presented.

关键词： Coronavirus pandemic model deterministic ordinary differential equations numerical methods convergence analysis

Optimality of Solution with Numerical Investigation for Coronavirus Epidemic Model

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2021年第5期67卷 1713-1728页

作者： Naveed Shahid Dumitru Baleanu Nauman Ahmed Tahira Sumbal Shaikh Ali Raza Muhammad Sajid Iqbal Muhammad Rafiq Muhammad aziz-ur rehman Department of Mathematics and Statistics The University of LahoreLahorePakistan Department of Mathematics University of Management and TechnologyLahorePakistan Department of Mathematics Cankaya UniversityBalgatAnkara06530Turkey Department of Medical Research China Medical University HospitalChina Medical UniversityTaichungTaiwanChina Institute of Space Sciences Magurele-BucharestRomania Department of Mathematics Lahore College for Women UniversityLahorePakistan Department of Mathematics National College of Business Administration and Economics LahorePakistan Department of Mathematics Faculty of SciencesUniversity of Central PunjabLahorePakistan

The novel coronavirus disease,coined as COVID-19,is a murderous and infectious disease initiated from Wuhan,*** killer disease has taken a large number of lives around the world and its dynamics could not be controlled so *** this article,the spatio-temporal compartmental epidemic model of the novel disease with advection and diffusion process is projected and *** counteract these types of diseases or restrict their spread,mankind depends upon mathematical modeling and medicine to reduce,alleviate,and anticipate the behavior of disease *** existence and uniqueness of the solution for the proposed system are ***,the solution to the considered system is made possible in a well-known functions *** this purpose,a Banach space of function is chosen and the solutions are optimized in the closed and convex subset of the *** essential explicit estimates for the solutions are investigated for the associated auxiliary *** numerical solution and its analysis are the crux of this ***,the consistency,stability,and positivity are the indispensable and core properties of the compartmental models that a numerical design must *** this end,a nonstandard finite difference numerical scheme is developed to find the numerical solutions which preserve the structural properties of the continuous *** M-matrix theory is applied to prove the positivity of the *** results for the consistency and stability of the design are also presented in this *** plausibility of the projected scheme is indicated by an appropriate *** simulations are also exhibited to conclude the results.

关键词： Spatio-temporal advection diffusion explicit estimates auxiliary data M-matrix

Spatio-Temporal Dynamics and Structure Preserving Algorithm for Computer Virus Model

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2021年第7期68卷 201-211页

作者： Nauman Ahmed Umbreen Fatima Shahzaib Iqbal Ali Raza Muhammad Rafiq Muhammad aziz-ur-rehman Shehla Saeed Ilyas Khan Kottakkaran Sooppy Nisar Department of Mathematics and Statistics The University of LahoreLahorePakistan Department of Mathematics University of Management and TechnologyLahorePakistan Department of Mathematics National College of Business Administration and EconomicsLahorePakistan Department of Mathematics Faculty of SciencesUniversity of Central PunjabLahorePakistan Faculty of Mathematics and Statistics Ton Duc Thang UniversityHo Chi Minh72915Vietnam Department of Mathematics College of Arts and Sciences at Wadi AldawaserPrince Sattam Bin Abdulaziz UniversityAlkharjSaudi Arabia

The present work is related to the numerical investigation of the spatio-temporal susceptible-latent-breaking out-recovered(SLBR)epidemic *** describes the computer virus dynamics with vertical transmission via the *** these types of dynamics models,the absolute values of the state variables are the fundamental requirement that must be fulfilled by the numerical *** taking into account this key property,the positivity preserving algorithm is designed to solve the underlying SLBR ***,the state variables associated with the phenomenon,represent the computer nodes,so they must take in ***,the continuous system(SLBR)acquires two steady states i.e.,the virus-free state and the virus existence *** stability of the numerical design,at the equilibrium points,portrays an exceptional aspect about the propagation of the *** designed discretization algorithm sustains the stability of both the steady *** computer simulations also endorse that the proposed discretization algorithm retains all the traits of the continuous SLBR model with spatial *** stability and consistency of the proposed algorithm are verified,*** the facts are also ascertained by numerical simulations.

关键词： Spatio-temporal computer virus model discretization positive solution computer simulations

Facile synthesis of samarium and cerium doped double perovskite cobaltite with enhanced dielectric response

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 2024年第7期42卷 1317-1327,I0005页

作者： Yasir Abbas M.Kamran M.Anis-ur-rehman Applied Thermal Physics Laboratory Department of PhysicsCOMSATS University IslamabadIslamabad 45550Pakistan

The investigation of Sm-Ce doping on structure,conduction,and dielectric response of Bi_(2)Ca_(2-2x)Sm_(x)CexCoO_(6)(x=0.000,0.025,0.050,0.075)(BCSCCO)are *** the specimens were synthesized by a facile synthesis technique named the co-precipitation route.X-ray diffraction(XRD)reveals that BCSCCO crystallizes into one phase with space group P21/*** crystallite size,dislocation density,lattice parameters,lattice strain,unit cell volume,and bulk density were determined using XRD *** structural properties of Bi_(2)Ca_(2)CoO_(6)were examined using calculations based on the density functional *** and experimental values discrepancy is less than 1%.A scanning electron microscope was used for performing a microstructural *** SEM images demonstrate the homogeneous distribution of grains with a range of sizes(0.054-0.090μm).The alternating current(ac)conductivity,dielectric permittivity,and tangent loss were also studied as a function of frequency(20 Hz-3 MHz)at different temperatures(100-500℃).All synthesized samples were examined using non-linear Debye's function to determine their spreading factor and relaxation *** specimen with the lowest crystallite size(∼23 nm)exhibits a high dielectric permittivity(∼3.80×10^(6)).The conduction mechanism was examined in the studied samples with the use of Jonscher's power *** power law indicates that the BCSCCO(x=0.000,0.025)follows correlated barrier hopping,whereas the x=0.050 and 0.075 compositions follow non-overlapping polaron *** studied specimen Bi_(2)Ca_(1.9)0Sm_(0.05)0Ce_(0.05)_(0)CoO_(6)with the highest density(∼5.65 g/cm^(3))displays a high electrical conductivity(∼46.1 S/cm).These findings correspond to those published for ceramics made from calcium cobaltite using solid-state reactions(5.0-26.0 S/cm).

关键词： Bismuth calcium samarium cerium cobaltite (BCSCCO) Spreading factor Conduction mechanism Rare earths

维普期刊数据库

Probing the Efficiency of PPMG-Based Composite Electrolytes for Applications of Proton Exchange Membrane Fuel Cell

在线全文

学校读者我要写书评

暂无评论

Transactions of Tianjin University 2024年第3期30卷 262-283页

作者： Shakeel Ahmed Faizah Altaf Safyan Akram Khan Sumaira Manzoor aziz Ahmad Muhammad Mansha Shahid Ali Ata-ur-rehman Karl Jacob School of Material Science and Engineering Henan International Joint Laboratory of Nano-Photoelectric Magnetic MaterialsHenan University of TechnologyZhengzhou 450001China Interdisciplinary Research Center for Hydrogen Technologies and Carbon Management King Fahd University of Petroleum and Minerals31261 DhahranSaudi Arabia School of Materials Science and Engineering Georgia Institute of TechnologyAtlantaGA 30332USA

PPMG-based composite electrolytes were fabricated via the solution method using the polyvinyl alcohol and polyvinylpyrrolidone blend reinforced with various contents of sulfonated inorganic *** acid was employed as the sulfonating agent to functionalize the external surface of the inorganic filler,i.e.,graphene *** proton conductivities of the newly prepared proton exchange membranes(PEMs)were increased by increasing the temperature and content of sulfonated graphene oxide(SGO),i.e.,ranging from 0.025 S/cm to 0.060 S/*** induction of the optimum level of SGO is determined to be an excellent route to enhance ionic *** single-cell performance test was conducted by sandwiching the newly prepared PEMs between an anode(0.2 mg/cm^(2) Pt/Ru)and a cathode(0.2 mg/cm^(2) Pt)to prepare membrane electrode assemblies,followed by hot pressing under a pressure of approximately 100 kg/cm^(2) at 60℃for 5–10 *** highest power densities achieved with PPMG PEMs were 14.9 and 35.60 mW/cm^(2) at 25℃and 70℃,respectively,at ambient pressure with 100%relative *** showed that the newly prepared PEMs exhibit good electrochemical *** results indicated that the prepared composite membrane with 6 wt%filler can be used as an alternative membrane for applications of high-performance proton exchange membrane fuel cell.

关键词： Proton exchange membrane fuel cell Sulfonated graphene oxide Polyvinylpyrrolidone Solution casting Membrane electrode assembly Fuel cell performance

维普期刊数据库