检索结果-南通市图书馆

Communications in theoretical Physics 2018年第7期69卷 49-59页

作者： Imran Haider Qureshi M.Nawaz Shafia Rana t.zubair Department of Applied Mathematics and Statistics Institute of Space and TechnologyIslamabad

this article investigates the effects of variable thermal conductivity and variable mass diffusion coefficient on the transport of heat and mass in the flow of Casson fluid. Numerical simulations for two-dimensional flow induced by stretching surface are performed by using Galerkin finite element method(GFEM) with linear shape functions. After assembly process, nonlinear algebraic equations are linearized through Picard method and resulting linear system is solved iteratively using Gauss Seidal method with simulation tolerance 10^(-8). Maximum value of independent variableη is searched through numerical experiments. Grid independent study was carried out and error analysis is *** results are validated by comparing with already published results. Parametric study is carried out to explore the physics of the flow. the concentration increases when mass diffusion coefficient is increased. the concentration and thermal boundary layer thicknesses increase when ?_1 and ? are increased. the effect of generative chemical reaction on concentration is opposite to the effect of destructive chemical reaction on the concentration.

关键词： variable diffusion coefficients grid independent study convergence error analysis Nusselt num-ber Casson fluid Joule heating viscous dissipation

Brownian motion and thermophoresis effects on unsteady stagnation point flow of Eyring-Powell nanofluid: a Galerkin approach

在线全文

学校读者我要写书评

暂无评论

Communications in theoretical Physics 2020年第12期72卷 71-82页

作者： Z H Khan M Usman t zubair M Hamid R U Haq State Key Laboratory of Hydraulics and Mountain River Engineering College of Water Resource and HydropowerSichuan UniversityChengdu610065China BIC-ESAt College of EngineeringPeking UniversityBeijing 100871China State Key Laboratory for turbulence and Complex Systems Department of Mechanics and Engineering SciencePeking UniversityBeijing 100871China Institute of Ocean Research Peking UniversityBeijing 100871China School of Mathematical Sciences Peking UniversityBeijing 100871China Department of Mechanics and Engineering Science Fudan UniversityShanghai 200433China Department of Electrical Engineering Bahria UniversityIslamabad CampusIslamabad 44000Pakistan

this article concerns the analysis of an unsteady stagnation point flow of Eyring–Powell nanofluid over a stretching *** influence of thermophoresis and Brownian motion is also considered in transport *** nonlinear ODE set is obtained from the governing nonlinear equations via suitable *** numerical experiments are performed using the Galerkin scheme.A tabular form comparison analysis of outcomes attained via the Galerkin approach and numerical scheme(RK-4)is available to show the credibility of the Galerkin *** numerical exploration is carried out for various governing parameters,namely,Brownian motion,steadiness,thermophoresis,stretching ratio,velocity slip,concentration slip,thermal slip,and fluid parameters,and Hartmann,Prandtl and Schmidt *** velocity of fluid enhances with an increase in fluid and magnetic parameters for the case of opposing,but the behavior is reversed for assisting *** Brownian motion and thermophoresis parameters cause an increase in temperature for both cases(assisting and opposing).the Brownian motion parameter provides a drop-in concentration while an increase is noticed for the thermophoresis *** the outcomes and the behavior of emerging parameters are illustrated *** comparison analysis and graphical plots endorse the appropriateness of the Galerkin *** is concluded that said method could be extended to other problems of a complex nature.

关键词： Eyring-Powell fluid stagnation point flow Brownian motion and thermophoresis Galerkin method

Impedance hygrometer based on cellulose and CuPc

在线全文

学校读者我要写书评

暂无评论

Journal of Semiconductors 2010年第6期31卷 70-73页

作者： Kh.S.Karimov t.A.Qasuria zubair Ahmad Ghulam Ishaq Khan Institute of Engineering Sciences and technology Physical technical Institute Aini St.299/1Dushanbe

An investigation has been made on the properties of an impedance hygrometer fabricated using cellulose and copper phthalocyanine（Ag/cellulose/CuPc/Ag）.A 5wt%suspension of cellulose was prepared in water while the CuPc was dissolved in *** film was deposited on glass substrates with preliminary deposited metallic electrodes followed by deposition of CuPc *** resistances and capacitances of the samples were evaluated under the effect of *** impedance was calculated from resistance and capacitance *** was also measured during the *** was observed that the capacitance of the sensor increases and resistance and impedance decrease with an increase in the relative humidity *** was found that the impedance-humidity relationship showed more uniform changes in the interval of 31%—98%RH than the resistance-and capacitance-humidity relationships that showed visible changes in the humidity intervals of 31%-80%RH and 80%-98%RH *** humidity-dependent impedance of the sample makes it attractive for use in impedance *** impedance hygrometer may be used in instruments for the environmental monitoring of humidity.

关键词： cellulose copper phthalocyanine organic hygrometer humidity impedance

Multi-objective vendor managed inventory system with interval type-2 fuzzy demand and order quantities

在线全文

学校读者我要写书评

暂无评论

International Journal of Intelligent Computing and Cybernetics 2021年第3期14卷 439-466页

作者： zubair Ashraf Mohammad Shahid South Asian University New DelhiIndiaand Aligarh Muslim University AligarhIndia

Purpose-the proposed It2FMOVMI model intends to concurrently minimize total cost and warehouse space for the single vendor-retailer,multi-item and a consolidated vendor *** demand and order quantities with the deterministic and type-1 fuzzy numbers,we have also formulated the classic/crisp MOVMI model and type-1 fuzzy MOVMI(t1FMOVMI)*** suggested solution technique can solve both crisp MOVMIand *** finding the optimal ordered quantities and backorder levels,the Paretofronts are constructed to form the solution sets for the three ***/methodology/approach-A multi-objective vendor managed inventory(MOVMI)is the most recognized marketing and delivery technique for the service provider and the retail in the supply chain in Industry *** to the evolving market conditions,the characteristics of the individual product,the delivery period and the manufacturing costs,the demand rate and order quantity of the MOVMI device are highly *** such a scenario,a MOVMI system with a deterministic demand rate and order quantity cannot be designed to estimate the highly unforeseen cost of the *** paper introduces a novel interval type-2 fuzzy multi-objective vendor managed inventory(It2FMOVMI)system,which uses interval type-2 fuzzy numbers(It2FNs)to represent demand rate and order *** the model is an NP-hard,the well-known meta-heuristic algorithm named NSGA-II(Non-dominated sorted genetic algorithm-II)with EKM(Enhanced Karnink-Mendel)algorithm based solution method has been ***-the experimental simulations for the five test problems that demonstrated distinct conditions are considered from the real-datasets of SAPCO *** study concludes that t1FMOVMI and crisp MOVMI schemes are outclassed by It2FMOVMI model,offering more accurate Pareto-Fronts and efficiency measurement ***/value-Using fuzzy sets theory,a significant amount of work has been already done in past

关键词： Multi-objective vendor managed inventory Interval type-2 fuzzy demand Interval type-2 fuzzy ordered quantity Industry 4.0 NSGA-II

Humidity sensitive organic field effect transistor

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 Semiconductors 2010年第5期31卷 40-44页

作者： I.Murtaza Kh S.Karimov zubair Ahmad I.Qazi M.Mahroof-tahir t.A.Khan t.Amin Ghulam Ishaq Khan Institute of Engineering Sciences and technology TopiSwabiNWFP23640Pakistan Physical technical Institute of Academy of Sciences Dushanbe 734025Tajikistan St.Cloud State University MN 56301-4498USA

this paper reports the experimental results for the humidity dependent properties of an organic field effect *** organic field effect transistor was fabricated on thoroughly cleaned glass substrate,in which the junction between the metal gate and the organic channel plays the role of gate *** films of organic semiconductor copper phthalocynanine（CuPc） and semitransparent Al were deposited in sequence by vacuum thermal evaporation on the glass substrate with preliminarily deposited Ag source and drain *** output and transfer characteristics of the fabricated device were *** effect of humidity on the drain current,drain current-drain voltage relationship, and threshold voltage was *** was observed that humidity has a strong effect on the characteristics of the organic field effect transistor.

关键词： organic field effect transistor CuPc metal-semiconductor Schottky junction humidity sensor

Physical aspects of anisotropic compact stars in f(t,t) gravity with off diagonal tetrad

在线全文

学校读者我要写书评

暂无评论

Chinese Physics C 2021年第8期45卷 190-205页

作者： M.zubair Allah Ditta G.Abbas Rabia Saleem Department of Mathematics COMSATS University IslamabadLahore CampusLahorePakistan Department of Mathematics The Islamia University of BahawalpurBahawalpurPakistan

this study addresses the formation of anisotropic compact star models in the background of f(t,t)gravity(where t and t represent the torsion and trace of the energy momentum tensor,respectively).f(t,t)gravity is an extension of the f(t)theory,and it allows a general non-minimal coupling between t and *** this setup,we apply Krori and Barua's solution to the static spacetime with the components ξ=Br^(2)+c and ψ=Ar^(2).to develop viable solutions,we select a well-known model f(t,t)=αt^(m)+βt+Ф(where α and β are coupling parameters,and Ф indicates the cosmological constant).We adopt the conventional matching of interior and exterior space time to evaluate the unknowns,which are employed in the stellar *** present a comprehensive discussion on the stellar properties to elaborate the anisotropic nature of compact stars corresponding to well-known models:PSRJ1416-2230,4U1608-52,CenX-3,EXO1785-248,and *** physical analysis,it is observed that the solution of compact spheres satisfy the acceptability criteria,and its models behave optimally and depict stability and consistency,in accordance with f(t,t)gravity.

关键词： f(t,t)gravity compact stars stellar models

On Modeling the Medical Care Insurance Data via a New Statistical 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1期66卷 113-126页

作者： Yen Liang tung zubair Ahmad G.G.Hamedani Accounting Department School of BusinessNanjing UniversityNanjingChina Department of Statistics Yazd UniversityYazdIran Department of Mathematical and Statistical Sciences Marquette UniversityMilwaukeeUSA

Proposing new statistical distributions which are more flexible than the existing distributions have become a recent trend in the practice of distribution *** often search for new and appropriate statistical models to address data related to financial and risk management *** the present study,an extension of the Lomax distribution is proposed via using the approach of the weighted t-X family of *** mathematical properties along with the characterization of the new model via truncated moments are *** model parameters are estimated via a prominent approach called the maximum likelihood estimation method.A brief Monte Carlo simulation study to assess the performance of the model parameters is *** application to medical care insurance data is provided to illustrate the potentials of the newly proposed extension of the Lomax *** comparison of the proposed model is made with the(i)two-parameter Lomax distribution,(ii)three-parameter models called the half logistic Lomax and exponentiated Lomax distributions,and(iii)A four-parameter model called the Kumaraswamy Lomax *** statistical analysis indicates that the proposed model performs better than the competitive models in analyzing data in financial and actuarial sciences.

关键词： Lomax distribution family of distributions financial sciences Monte Carlo simulation estimation

Solute drag-controlled grain growth in magnesium investigated by quasi in-situ orientation mapping and level-set simulations

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 Magnesium and Alloys 2023年第7期11卷 2312-2325页

作者： Risheng Pei Yujun Zhao Muhammad zubair Sangbong Yi talal Al-Samman Institut für Metallkunde und Materialphysik RWTH Aachen University52056 AachenGermany Institute of Materials and Process Design Helmholtz-Zentrum Hereon21502 GeesthachtGermany Department of Metallurgical and Materials Engineering Faculty of ChemicalMetallurgical&Polymer EngineeringUniversity of Engineering&Technology(UET)LahorePakistan Institute for Materials Ruhr-Universität Bochum44801 BochumGermany

Critical properties of metallic materials,such as the yield stress,corrosion resistance and ductility depend on the microstructure and its grain size and size *** atoms that favorably segregate to grain boundaries produce a pinning atmosphere that exerts a drag pressure on the boundary motion,which strongly affects the grain growth behavior during *** the current work,the characteristics of grain growth in an annealed Mg-1 wt.%Mn-1 wt.%Nd magnesium alloy were investigated by advanced experimental and modeling *** quasi in-situ orientation mappings with a scanning electron microscope were performed to track the evolution of local and global microstructural characteristics as a function of annealing *** segregation at targeted grain boundaries was measured using three-dimensional atom probe ***-set computer simulations were carried with different setups of driving forces to explore their contribution to the microstructure development with and without solute *** results showed that the favorable growth advantage for some grains leading to a transient stage of abnormal grain growth is controlled by several drivers with varying importance at different stages of *** longer annealing times,residual dislocation density gradients between large and smaller grains are no longer important,which leads to microstructure stability due to predominant solute *** fluctuations in residual dislocation energy and solute concentration near grain boundaries cause different boundary segments to migrate at different rates,which affects the average growth rate of large grains and their evolved shape.

关键词： Magnesium alloys Grain growth Quasi in-situ EBSD Level-set simulation Solute drag Dislocation density gradient

Cytotoxic activity and phytochemical standardization of Lunasia amara Blanco wood extract

在线全文

学校读者我要写书评

暂无评论

Asian Pacific Journal of tropical Biomedicine 2016年第11期6卷 962-966页

作者： Muhammad Sulaiman zubair Syariful Anam Subehan Lallo Department of Pharmacy Faculty of Science Tadulako University Department of Pharmacognosy and Phytochemistry Faculty of Pharmacy Hasanuddin University

Objective: to evaluate the cytotoxic activity of wood extracts of Lunasia amara Blanco(L. amara) and to perform further phytochemical ***: the wood extracts of L. amara were assessed for cytotoxic activity by in vitro tetrazolium bromide(Mtt) method against two human cancer cell lines, cervical cancer cells(He La) and breast cancer cells(t47D). thin layer chromatography, Dragendorf,acetic anhydride-sulfuric acid and ferric chloride were used to detect alkaloids, steroids and polyphenols, respectively. Furthermore, quantitative determination of total alkaloid by ultra fast liquid chromatography-photodiode array detection using lunacrine as a marker compound was performed as ***: the ethyl acetate extract exhibited higher cell-growth inhibition than methanol and n-hexane extracts on He La and t47 D cancer line cells with the IC50 of 71.15 and79.04 mg/m L, respectively. total alkaloid in ethyl acetate extract was counted as(10.46 ± 0.28)%(w/w), while lunacrine determined by ultra fast liquid chromatographyphotodiode array detection method was found to be(3.55 ± 0.26)%(w/w).Conclusions: the high total alkaloid and lunacrine concentration on the extract confirm the potential cytotoxic property of ethyl acetate wood extract of L. amara.

关键词： Lunasia amara Anticancer HeLa t47D total alkaloid Lunacrine

On the Genesis of the Marshall-Olkin Family of Distributions via the t-X Family Approach: Statistical Modeling

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4期67卷 753-760页

作者： Yang Zhenwu zubair Ahmad Zahra Almaspoor Saima K.Khosa College of Management and Economics Tianjin UniversityTianjinChina Department of Statistics Yazd UniversityYazdIran Department of Statistics Bahauddin Zakariya UniversityMultanPakistan

In the last couple of years,there Has been an increased interest among the statisticians to dene new families of distributions by adding one or more additional parameter(s)to the baseline *** this regard,a number of families have been introduced and *** such example is the Marshall-Olkin family of distributions that is one of the most prominent approaches used to generalize the existing ***,we see a new method,the natural questions come in to mind are(i)what are the genesis of the newly proposed method and(ii)how did the proposed method is *** doubt,the Marshall-Olkin family is a very useful method and has attracted the ***,unfortunately,the authors failed to provide the explanation about the genesis of the method that how this family of distributions is *** address this issue,in this article,an attempt Has been made to provide a straight forward computation about the genesis of the Marshall-Olkin family that somehow completes its *** genesis of the Marshall-Olkin family is based on the t-X family ***,we have showed that other extensions of the Marshall-Olkin family can also be obtained via the t-X family ***,a real-life application form insurance science is presented to illustrate the newly proposed extension of the Marshall-Olkin family.

关键词： Family of distributions Marshall-Olkin family t-X family approach statistical modeling