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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： Galerkin 有限元素电导率可变集体学习传导数字模拟

Effect of pressure on the electrical properties of flexible NiPc thin films fabricated by rubbing-in technology

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Chinese Physics B 2021年第1期30卷 328-331页

作者： Khasan S Karimov Fahmi F Muhammadsharif zubair Ahmad M Muqeet Rehman Rashid ali GIK Institute of Engineering Sciences and Technology TopiDistrict SwabiKPK23640Pakistan Center for Innovative Development of Science and New Technologies of Academy of Sciences of Tajikistan Dushanbe734025 Department of Physics Faculty of Science and HealthKoya University44023 KoyaKurdistan Region-F.R.Iraq Center for Advanced Materials(CAM) Qatar UniversityP.O.Box 2713DohaQatar Department of Electronic Engineering Jeju National UniversityJejuRepublic of Korea

Nickel phthalocyanine(Ni Pc) film was deposited onto the surface of flexible conductive glass by rubbing-in technology and used to fabricate devices based on ITO/Ni Pc/CNT/rubber structure. The I–V characteristics of the devices were investigated under different uniaxial pressures of 200, 280, and 480 gf/cm^(2), applied perpendicular to the surface of the Ni Pc film. Results showed that the nonlinearity coefficients of the I–V curves are in the range of 2 to 3, which was found to be decreased with the increase of the pressure. The rectification ratio of the devices was estimated to be varied from 1.5 to 3 based on the applied pressure. Concluding, the resistance of the active layers was decreased with the increase of both pressure and voltage. We believe that using the rubbing-in technology under sufficient applied pressure it is possible to utilize Ni Pc for the development of various electronic devices such as diodes, nonlinear resistors, and sensors.

关键词： pressure electrical property NiPc thin film rubbing-in technology

Optical sensors based on the NiPc-CoPc composite films deposited by drop casting and under the action of centrifugal force

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Chinese Physics B 2017年第6期26卷 114-118页

作者： Noshin Fatima Muhammad M Ahmed Khasan S Karimov zubair Ahmad Fahmi Fariq Muhammad Department of Electrical Engineering Capital University of Science and Technology (CUST) Islamabad 44000 Pakistan GIK Institute of Engineering Sciences and Technology Topi District Swabi KPK 23640 Pakistan Center for Innovative Development of Science and New Technologies of Academy of Sciences Aini 299/2 Dushanbe 734063 Tajikistan Center for Advanced Materials (CAM) Qatar University P. O. Box 2713 Doha Qatar Center for Composites Institute for Vehicle Systems & Engineering Faculty of Mechanical Engineering Universiti Teknologi Malaysia 81310 Johor Bahru Johor Malaysia Soft Materials & Devices Laboratory Department of Physics Faculty of Science and Health Koya University Danielle Mitten'and Boulevard Koya 45 Kurdistan Region Iraq

In this study, solution processed composite films of nickel phthalocyanine（NiPc） and cobalt phthalocyanine（CoPc）are deposited by drop casting and under centrifugal force. The films are deposited on surface-type inter-digitated silver electrodes on ceramic alumina substrates. The effects of illumination on the impedance and capacitance of the NiPc–CoPc composite samples are investigated. The samples deposited under centrifugal force show better conductivity than the samples deposited by drop casting technique. In terms of impedance and capacitance sensitivities the samples fabricated under centrifugal force are more sensitive than the drop casting samples. The values of impedance sensitivity（Sz）are equal to（-1.83） MΩ·cm^2/mW and（-5.365） MΩ·cm^2/mW for the samples fabricated using drop casting and under centrifugal force, respectively. Similarly, the values of capacitance sensitivity（Sc） are equal to 0.083 pF·cm^2/mW and 0.185 pF·cm～2/mW for the samples fabricated by drop casting and under centrifugal force. The films deposited using the different procedures could potentially be viable for different operational modes（i.e., conductive or capacitive） of the optical sensors. Both experimental and simulated results are discussed.

关键词： optical sensors capacitive mode impedance mode centrifugal deposition

氧化锌纳米颗粒的形貌控制合成及其体外抗菌活性

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Transactions of Nonferrous Metals Society of China 2020年第6期30卷 1605-1614页

作者： Naila zubair Khalida AKHTAR National Center of Excellence in Physical Chemistry University of PeshawarPeshawar-25120Khyber PukhtoonkhwaPakistan

在不使用任何表面活性剂或模板的情况下,采用可控沉淀法在水溶液中成功合成形貌均匀的分层花状和纳米棒状氧化锌(ZnO)。为了阐明纳米颗粒的生长机理,系统研究pH、反应时间和温度对纳米颗粒形貌的影响。采用SEM、FT-IR和XRD等表征手段对... 详细信息

在不使用任何表面活性剂或模板的情况下,采用可控沉淀法在水溶液中成功合成形貌均匀的分层花状和纳米棒状氧化锌(ZnO)。为了阐明纳米颗粒的生长机理,系统研究pH、反应时间和温度对纳米颗粒形貌的影响。采用SEM、FT-IR和XRD等表征手段对样品进行分析。XRD谱证实合成的粉末具有良好的结晶性。此外,对比研究合成的花状(ZnO-1)和纳米棒状(ZnO-2)的ZnO纳米颗粒与商业ZnO(ZnO-Com)颗粒的体外抗菌活性。结果表明,在实验条件下,ZnO-2比ZnO-1对受试菌具有更高的抗菌活性,而商业ZnO则没有抗菌活性。当ZnO-2的浓度从0.25升高到0.75μg/μL时,对变异链球菌的抑菌环从约30 mm扩大到33 mm,对大肠杆菌的抑菌环从约28mm增大到30mm。研究表明,合成的氧化锌纳米颗粒作为抗菌剂,可能在生物医学方面有效抑制某些致病菌。

关键词： ZnO 纳米颗粒菌株抗菌活性

基于新型形貌的纳米结构氧化锌高性能室温气体传感器（英文）

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Transactions of Nonferrous Metals Society of China 2019年第1期29卷 143-156页

作者： Naila zubair Khalida AKHTAR National Center of Excellence in Physical Chemistry University of Peshawar

通过简单快速且无添加剂的氨水可控沉淀法在水溶液中制备具有新型形貌和均匀纳米结构的氧化锌粉末。用SEM、XRD、FTIR、TG/DTA等检测手段表征所制备的固体粉末。FTIR分析结果显示:纳米结构形貌对所制备材料的红外光谱影响较小。将原始态... 详细信息

通过简单快速且无添加剂的氨水可控沉淀法在水溶液中制备具有新型形貌和均匀纳米结构的氧化锌粉末。用SEM、XRD、FTIR、TG/DTA等检测手段表征所制备的固体粉末。FTIR分析结果显示:纳米结构形貌对所制备材料的红外光谱影响较小。将原始态(ZnO-AP)、烧结态(ZnO-Cal)和商业(ZnO-Com)纳米结构ZnO制作成气敏元件,并在室温(29℃)下检测其对氨气、丙酮和酒精的气敏性能。结果表明,ZnO-AP和ZnO-Cal气敏元件对1×10^(-6)的氨气表现出优良的气敏性能和可重复性,灵敏度分别为63.79%和66.87%,响应和恢复时间分别为13和3 s;这是由于合成的纳米结构具有独特的形貌和优异的形状与尺寸均匀性。相反,ZnO-Com气敏元件对浓度200×10^(-6)以下的氨气没有响应。另外,ZnO-Cal在室温下对氨气的选择性高于对丙酮和酒精的选择性。总之,合成的ZnO对氨气的最低检测限为1×10^(-6),表明其具有优异的气敏特性。

关键词：氧化锌纳米结构气体传感器敏感性响应/恢复时间

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

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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

The Determinants of Chinese Outward Foreign Direct Investment:A Closer Look

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Frontiers of Economics in China-Selected Publications from Chinese Universities 2018年第4期13卷 577-601页

作者： Muhammad zubair Mumtaz Zachary alexander Smith School of Social Sciences&Humanities National University of Sciences&TechnologyH-12IslamabadPakistan Department of Economics Saint Leo UniversitySaint LeoFL 33574USA

Over the last fifteen years, China rapidly expanded its outward foreign direct investment (OFDI) through remarkable economic growth and the “go global” policy. Chinese firms explored investment avenues especially in developing and emerging countries. As a result, China became the third largest contributor of OFDI. We examine the determinants of Chinese OFDI in 67 countries during the period lasting from 2006 to 2015 using the feasible generalized least square method. We find that the size of the economy, market opportunities, cost advantages due to low wage structure, ease of doing business, country risk, and geographical proximity are the prominent factors leading to changes in Chinese OFDI in developing and emerging economies. We find that China’s investments in different developing and emerging countries are driven by a different set of factors and the determinants of Chinese OFDI vary in low and high per capita income countries.

关键词： China outward foreign direct investment (OFDI) emerging and developing countries globalization

Scenario of dengue infection & its control in Pakistan: An up-date and way forward

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Asian Pacific Journal of Tropical Medicine 2018年第1期11卷 15-23页

作者： Muhammad zubair Yousaf Adeena Siddique Usman ali Ashfaq Muhammad ali Department of Biological Sciences Forman Christian College(A Chartered University) Department of Bioinformatics and Biotechnology Government College University Faisalabad Department of Biotechnology Quad-e Azam University Islamabad

Dengue fever is one of the major health problems in tropical and subtropical areas throughout the world. The causative agent of dengue fever is the dengue virus which is an enveloped single stranded RNA virus belongs to the family Flaviviridae and has five distinct serotypes(DENV-1,DENV-2, DENV-3, DENV-4 and DENV-5). Dengue virus is transmitted to human via bite of Aedes aegypti and Aedes albopictus mosquitoes. The clinical symptoms of dengue fever ranging from mild to severe form as dengue hemorrhagic fever and dengue shock syndrome. Pakistan is dengue endemic since 1994 but from 2006, Pakistan faced the worst condition regarding dengue in which thousands of people affected by the disease and hundreds of people lost their lives. DENV-2, DENV-3 and DENV-1 are the prevalent serotypes in Pakistan. Common diagnostic techniques are being used in Pakistan such as enzyme-linked immunosorbent assay,polymerase chain reaction and rapid diagnostic tests, while differential diagnosis, limitations of diagnostic methods and poor health care system are the real challenges in dengue *** climatic conditions, unplanned urbanization, travelling etc., are major factors responsible for dengue epidemics in Pakistan. This presentation provides update about dengue circumstances in Pakistan and also describes the way how to improve dengue situation in Pakistan.

关键词： Dengue infection Diagnosis Treatment Prevention Pakistan

Gastric juice for the diagnosis of H pylori infection in patients on proton pump inhibitors

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World Journal of Gastroenterology 2008年第10期14卷 1539-1543页

作者： Javed Yakoob Shahid Rasool Zaigham Abbas Wasim Jafri Shahab Abid Muhammad islam zubair Ahmad Department of Medicine Aga Khan University Hospital Karachi 74800 Pakistan Department of Pathology Aga Khan University Hospital Karachi 74800 Pakistan

AIM: To determine the efficacy of gastric juice polymerase chain reaction (PCR) for the detection of H pylori infection in comparison with histology and gastric antral biopsy PCR in patients on a proton pump inhibitor (PPI). METHODS: Eighty-five consecutive patients with dyspeptic symptoms were enrolled. Gastric biopsies for histology, PCR and gastric juice were collected at endoscopy for PCR of the H pylori urease C gene (ure C). Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy, positive and negative likelihood ratio for PCR of gastric juice for the H pylori ure C gene was compared to histology and gastric antral biopsy H pylori ure C PCR in patients with and without PPI. RESULTS: Gastric juice PCR was positive in 66 (78%) patients. Histology showed H pylori associated gastritis in 57 (67%). Gastric biopsy PCR was positive in 72 (85%). In patients not taking PPI, the sensitivity, specificity, PPV, NPV, accuracy and positive and negative likelihood ratio for gastric juice PCR were 89%, 72%, 91%, 67%, 90%, 85%, 3.1 and 0.1 respectively. In patients on PPI these values were 86%, 100%%, 100%, 29%, 86%, 9.5 and 1.4, respectively. CONCLUSION: Gastric juice PCR for the diagnosis of H pylori infection has increased sensitivity compared to histology with PPI. The use of gastric juice PCR is recommended to confirm H pylori status in patients taking PPIs.

关键词：幽门杆菌质子泵抑制剂胃汁聚合酶联反应

Antibody seropositivity and endemicity of chikungunya and Zika viruses in Nigeria

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Animal Diseases 2023年第2期3卷 104-114页

作者： Peter Asaga Mac Philomena E.Airiohuodion Raman Velayudhan Shaistha zubair Markos Tadele Jude,O.Aighobahi Chukwuma Anyaike Axel Kroeger Marcus Panning Institute of Virology University Medical FreiburgHermann Herder Str1179104 FreiburgGermany World Health Organization Special Programme for Research and Training in Tropical Diseases(TDR)Avenue Appia 201211 Geneva 27Switzerland World Health Organization WHO/NTD UnitAvenue Appia 201211 Geneva 27Switzerland Maldives National University BuruzuMaguMaleMaldives Ethiopian Institute Of Agricultural Research/EIAR Addis AbabaEthiopia Icon Clinical Research Heinrich‑Hertz Starsse 2663225 Langen HessenBerlinGermany Federal Ministry of Health National Tuberculosis and Leprosy ControlProgrammeAbujaNigeria Centre for Medicine and Society Faculty of MedicineUniversity of FreiburgFreiburgGermany

Mosquito-borne infections are of global health concern because of their rapid spread and upsurge,which creates a risk for *** virus(CHIKV),an arbovirus disease transmitted by Aedes aegypti or ***,and malaria,a parasitic disease transmitted by Anopheles gambiae,are prevalent in Nigeria and neighbouring countries,but their burden and possible coinfections are poorly *** this study,we investigated the antibody seropositivity and endemicity of chikungunya and Zika viruses(ZIKV)in three regions of Nigeria.A cross-sectional serosurvey was conducted on 871 *** were collected from outpatients by simple random *** of the samples were performed using recomLine Tropical Fever for the presence of antibody serological marker IgG immunoblot with CHIKV VLP(virus like particle),ZIKV NS1 and ZIKV Equad according to manufacturers’instructions and malaria RDT for malaria *** was a significantly higher antibody seropositivity against CHIKV in the central region than in the northern and southern regions(69.5%,291/419),while ZIKV-seropositivity(22.4%,34/152)and CHIKV-ZIKV co-circulating antibody seropositivity(17.8%,27/152)were notably higher in the southern region than in the central and northern *** investigation revealed an unexpectedly high antibody seropositivity and concealed endemicity of CHIKV and ZIKV in three Nigerian *** seropositivity of detectable antibodies differed among the three geographical locations.

关键词： Chikungunya Zika Cocirculation Seroprevalence Nigeria Endemicity Malaria