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Natural Propulsion with Lorentz Force and Nanoparticles in a Bioinspired Lopsided Ciliated Channel

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Journal of Bionic Engineering 2017年第1期14卷 172-181页

作者： Noreen Sher Akbar Liaqat Ali Khan zafar hayat Khan Nazir Ahmed Mir DBS&H CEME National University of Sciences and Technology Islamabad Pakistan Basic Science Department Ripha International University Islamabad Pakistan Department of Mathematics University of Malakand Chakdara Dir (Lower) Khyber Pakhtunkhwa Pakistan

The transportation of biological and industrial nanofluids by natural propulsion like cilia movement and self-generated contraction-relaxation of flexible walls has tremendous applications in various fields. Inspired by multidisciplinary invention in this direction, a fuid mechanical model is proposed to study the Magneto-hydrodynamics （MHD） and heat transfer for nanofluids fabricated by the dispersion of nanoparticles in water as base fluid. The steady flow is induced by metachronal wave propulsion due to beating cilia. The flow regime is asymmetric channel. The flow is restricted under the low Reynolds number and long wavelength approximations. Cilia boundary conditions for velocity components are employed to find the exact solutions. The impacts of pertinent physical parameters on temperature profile, velocity profile, pressure, and stream lines are computed numerically. It is observed that velocity is inversely proportional to magnetic Reynolds number, Reynolds number, Strommer＇s number and velocity is directly proportional to flow rate. It is analyzed that temperature is inversely proportional to Strommer＇s number and magnetic Reynolds number and directly proportional to Brinkmann number and flow rate. The temperature is maximum at the center of the channel and it starts decreasing towards the boundary walls.

关键词： copper water nanoparticles induced magnetic field asymmetric ciliated channel

Estimation of boundary-layer flow of a nanofluid past a stretching sheet: A revised model

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Journal of Hydrodynamics 2016年第4期28卷 596-602页

作者： Naeema ISHFAQ zafar hayat KHAN Waqar Ahmad KHAN Richard J.CULHAM School of Mathematical Sciences Peking University Department of Mathematics University of MalakandDir (Lower) Department of Mechanical and Industrial Engineering College of EngineeringMajmaah University Department of Mechanical Engineering University of Waterloo

The previous model for the boundary layer nanofluid flow past a stretching surface with a specified nanoparticle volume fraction on the surface is *** major limitation of the previous model is the active control of the nanoparticle volume fraction on the *** a revised model proposed in this paper,the nanoparticle volume fraction on the surface is passively controlled,which accounts for the effects of both the Brownian motion and the thermophoresis under the boundary condition,whereas the Buongiorno＇s model considers both effects in the governing *** assumption of zero nanoparticle flux on the surface makes the model physically more *** the revised model,the dimensionless heat transfer rates are found to be higher whereas the dimensionless mass transfer rates are identically zero due to the passive boundary *** is also found that the Brownian motion parameter has a negligible effect on the Nusselt number.

关键词： stretching Brownian dimensionless revised identically governing realistic physically electrically negligible

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微通道中气泡生成的研究

微通道中气泡生成的研究

作者： zafar hayat 天津大学

学位级别：硕士

微化学工程与技术是化学过程强化的重要手段之一。由于其传质性能好、安全性强、并行放大策略等特点,引起了人们的广泛关注。本文利用高速摄像仪对并行微通道和台阶型微通道装置中气泡生成过程、气液两相流的稳定性和均匀性、以及气泡... 详细信息

微化学工程与技术是化学过程强化的重要手段之一。由于其传质性能好、安全性强、并行放大策略等特点,引起了人们的广泛关注。本文利用高速摄像仪对并行微通道和台阶型微通道装置中气泡生成过程、气液两相流的稳定性和均匀性、以及气泡生成的影响机制进行了实验研究。探究了四种不同构型并行微通道中气泡的生成机理。研究了气液两相流量、液体粘度和通道结构对气泡生成的稳定性和均匀性的影响机制。结果表明,随着气相流量、液相流量和液相粘度的增加,气泡生成过程趋于稳定。两并行微通道内气泡长度的均匀性随气相流量、液体粘度的减小、以及液体流量的增大而增强。此外,研究了并行微通道中气泡长度的相对偏差,发现随着液相流量和粘度的增加,气泡长度的相对偏差减小。考虑到气相流量、液相流量和液体粘度的影响因素,提出了四种构型微装置中两并行微通道内气泡生成尺寸的预测模型。探究了台阶式微通道内气泡生成机理。以氮气作为分散相、甘油水溶液为连续相。实验设计了三种台阶式微乳化装置,其步宽尺寸分别为0.4 mm、0.7mm和1 mm。利用气泡颈部宽度作为特征参数,研究了气泡生成过程气液界面的演变规律。结果表明,气泡经历了膨胀阶段和致细破裂阶段。气体细丝颈部宽度随时间先增大,过一段时间后,由于受限空间内气液界面失稳而开始减小。结果表明,气泡体积随气相流量的增大而增大,随着液体流量的增加而减小。本文工作为进一步研究气泡生成放大涉及的并行台阶式微乳化装置中气泡动力学机制奠定了良好的基础。

关键词：并行微通道台阶式乳化器界面气泡流体动力学

Mechanical Integrity and Failure Analysis of Photovoltaic Modules under Simulated Snow Loads Using Pneumatic Airbag Setup

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Journal of Power and Energy Engineering 2022年第1期10卷 1-13页

作者： Nouman Ali Shah Rizwan M. Gul zafar hayat Khan State Key Laboratory of Polymer Materials Engineering College of Polymer Science and Engineering Sichuan University Chengdu China Department of Mechanical Engineering University of Engineering and Technology Peshawar Pakistan State Key Laboratory of Hydraulics and Mountain River Engineering College of Water Resource and Hydropower Sichuan University Chengdu China

Photovoltaic (PV) modules have emerged as an ideal technology of choice for harvesting vastly available renewable energy resources. However, the efficiency of PV modules remains significantly lower than that of other renewable energy sources such as wind and hydro. One of the critical elements affecting a photovoltaic module’s efficiency is the variety of external climatic conditions under which it is installed. In this work, the effect of simulated snow loads was evaluated on the performance of PV modules with different types of cells and numbers of busbars. According to ASTM-1830 and IEC-1215 standards, a load of 5400 Pa was applied to the surface of PV modules for 3 hours. An indigenously developed pneumatic airbag test setup was used for the uniform application of this load throughout the test, which was validated by load cell and pressure gauge. Electroluminescence (EL) imaging and solar flash tests were performed before and after the application of load to characterize the performance and effect of load on PV modules. Based on these tests, the maximum power output, efficiency, fill factor and series resistance were determined. The results show that polycrystalline modules are the most likely to withstand the snow loads as compared to monocrystalline PV modules. A maximum drop of 32.13% in the power output and a 17.6% increase in series resistance were observed in the modules having more cracks. These findings demonstrated the efficacy of the newly established test setup and the potential of snow loads for reducing the overall performance of PV module.

关键词： Photovoltaic Modules Pneumatic Testing Setup Mechanical Integrity Electroluminescence Testing Electrical Performance

Approximation of some minerals in soil and forage as a function of non-conventional compost: A case study

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Agricultural Sciences 2013年第1期4卷 6-13页

作者： Kafeel Ahmad zafar Iqbal Khan Sidra Umer Farhad Mirzaei Muhammad Sher zafar hayat Abrar Hussain Department of Animal Sciences University of Sargodha Sargodha Pakistan Department of Biological Sciences University of Sargodha Sargodha Pakistan Department of Chemistry University of Sargodha Sargodha Pakistan Division of Science and Technology University of Education Lahore Pakistan Livestock Production & Management Animal Husbandry Economics Animal Science Research Institute of Iran Karaj Iran

In present study concentration of some metals (Magnesium, Nickel and Calcium) were determined in soil and different parts of Avena sativa treated with poultry waste grown in the pots. Nine different treatments of poultry waste were used: 0 (control), 60, 90, 120 and 150 kg/ha applied to soil as full doses before sowing, and 60, 90, 120, and 150 applied as two equal splits, 1st before sowing and the 2nd before flower instigation. The samples of soil were obtained after mixing the poultry waste with soil in each pot before sowing. Different parts (roots, leaves, and seeds) of plants were taken after 90 days of sowing and after grain filling. Samples of soil and forages were analyzed. Mg concentrations found both in soil and plants were non-significantly affected by treatments and were lower than the requirements of ruminants in forage crops, but above requirement of forages in soil. Soil and forage Ni was affected non-significantly from the treatments of poultry waste and soil and forage Ni levels were found to be lower than the toxic level for animals and forages. Soil Ca was affected non-significantly by treatments having far lower values than the requirements of both forage species and ruminants. The study showed that soil Mg was higher and Ca was lower than the requirements of forages, but forage Mg and Ca were not fulfilling the requirements of livestock indicating the non significant effect of poultry waste on their concentrations. From the results of this study it has been anticipated that various deficiency problems in livestock may be resulted as these elements play very important role in animals’ metabolic progression. Therefore, soil amendment with poultry manure along with other synthetic fertilizers for enhancing the levels of various minerals is acceptable. The soil amendment and specifically tailored mineral mixture with appropriate proportion of these elements is the dire needs for livestock consuming Avena sativa in pasture treated with poultry waste.

关键词： Mineral Forage Soil Non-Conventional Fertilizer

Density functional theory study of structural,electronic,and thermal properties of Pt,Pd,Rh,Ir,Os and PtPdX(X=Ir,Os,and Rh)alloys

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Chinese Physics B 2016年第3期25卷 298-306页

作者： Shabbir Ahmed Muhammad zafar M Shakilt M A Choudhary Simulation Laboratory Department of Physicsthe Islamia University of BahawalpurBahawalpur 63100Pakistan o Department of Physics Hafiz Hayat CampusUniversity of GujratGujrat 50700Pakistan

The structural, electronic, mechanical, and thermal properties of Pt, Pd, Rh, Ir, Os metals and their alloys PtPdX （X = Ir, Os and Rh） are studied systematically using ab initio density functional theory. The groundstate properties such as lattice constant and bulk modulus are calculated to find the equilibrium atomic position for stable alloys. The electronic band structure and density of states are calculated to study the electronic behavior of metals on making their alloys. The electronic properties substantiate the metallic behavior for all studied materials. The firstprinciples density functional perturbation theory as implemented in quasi-harmonic approximation is used for the calculations of thermal properties. We have calculated the thermal properties such as the Debye temperature, vibrational energy, entropy and constant-volume specific heat. The calculated properties are compared with the previously reported experimental and theoretical data for metals and are found to be in good agreement. Calculated results for alloys could not be compared because there is no data available in the literature with such alloy composition.

关键词： electronic structural and thermal properties platinum group metals

Theoretical calculations of structural, electronic, and elastic properties of CdSe_(1-x)Te_x:A first principles study

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Chinese Physics B 2016年第7期25卷 324-330页

作者： M Shakil Muhammad zafar Shabbir Ahmed Muhammad Raza-ur-rehman Hashmi M A Choudhary T Iqbal Department of Physics Hafiz Hayat Campus University of Gujrat Simulation Laboratory Department of Physics the Islamia University of Bahawalpur

The plane wave pseudo-potential method was used to investigate the structural, electronic, and elastic properties of Cd Se_（1-x）Te_x in the zinc blende phase. It is observed that the electronic properties are improved considerably by using LDA ＋ U as compared to the LDA approach. The calculated lattice constants and bulk moduli are also comparable to the experimental results. The cohesive energies for pure Cd Se and Cd Te binary and their mixed alloys are calculated. The second-order elastic constants are also calculated by the Lagrangian theory of elasticity. The elastic properties show that the studied material has a ductile nature.

关键词： first principles calculations density functional theory II–VI semiconductors structural electronic and elastic properties

First-principles calculation of the structural,electronic,and magnetic properties of cubic perovskite RbXF3(X = Mn,V,Co,Fe)

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Chinese Physics B 2016年第11期25卷 486-491页

作者： Muhammad Raza ur rehman Hashmi Muhammad zafar M Shakil Atif Sattar Shabbir Ahmed S A Ahmad Simulation Laboratory Department of Physics The Islamia University of Bahawalpur 63100 Pakistan Department of Physics Hafiz Hayat Campus University of Gujrat Gujrat Pakistan

First-principles calculations by means of the full-potential linearized augmented plane wave method using the generalized gradient approximation with correlation effect correction（GGA＋U） within the framework of spin polarized density functional theory（DFT＋U） are used to study the structural,electronic,and magnetic properties of cubic perovskite compounds RbXF3（X = Mn,V,Co,and Fe）.It is found that the calculated structural parameters,i.e.,lattice constant,bulk modulus,and its pressure derivative are in good agreement with the previous *** results reveal that the strong spin polarization of the 3d states of the X atoms is the origin of ferromagnetism in *** energies and the magnetic moments of RbXF3 have also been *** calculated electronic properties show the half-metallic nature of RbCoF3 and RbFeF3,making these materials suitable for spintronic applications.

关键词： cubic metallic perovskite modulus correction linearized ferromagnetic augmented instance spheres

Ethnobotanical Study of Medicinal Plants of Semi-Tribal Area of Makerwal &Gulla Khel (Lying between Khyber Pakhtunkhwa and Punjab Provinces), Pakistan

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American Journal of Plant Sciences 2013年第1期4卷 98-116页

作者： Amin Shah Sarfaraz Khan Marwat Faryal Gohar Ameer Khan Khizar hayat Bhatti Muhammad Amin Noor Ud Din Mushtaq Ahmad Muhammad zafar Department of Biological Sciences University of Sargodha Sargodha Pakistan Department of Botany Institute of Chemical and Biological Sciences University of Gujrat Gujrat Pakistan Department of Chemistry University of Sargodha Sargodha Pakistan Department of Plant Sciences Quaid-i-Azam University Islamabad Pakistan University Wensam College Gomal University Dera Imail Khan Pakistan

This paper is based on the results of an ethnomedicinal research work conducted in the semi-tribal mountainous area lying between District Mianwali (PunjabProvince) and District Karak (KhyberPakhtunkhwaProvince),Pakistanduring June 2009-July 2011. During field survey, questionnaires were used to interview the local inhabitants of the area. The ethnomedicinal data consists of 131 plant species (2 Pteridophytes, 7 Monocots, 122 Dicots) belonging to 48 families (2 Pteridophytes, 4 Monocots, 42 Dicots). The most commonly represented families were Amaranthaceae (9 spp.), Mimosaceae (8 spp.), Asteraceae and Papilionaceae (7 spp.) each;Solanaceae, Euphorbiaceae and Scrophulariaceae (6 spp.) each, followed by Boraginaceae, Brassicaceae, Lamiaceae and Polygonaceae (5 spp.) each. Plant specimens were identified, preserved and vouchers were deposited in the Plant Taxonomy Lab. of Department of Biological Sciences,University of Sargodha,Pakistanfor future reference. The data collected through interviews with the local people indicates that these species are mostly used in respiratory tract infections (RTI), urinary tract infections (UTI), digestive disorders, sexual problems, skin diseases, liver ailments, wound healing, blood vomiting, malaria, piles, epilepsy, jaundice, gummosis, round worms, hepatitis etc. in the area. Due to lack of scientific approach regarding harvesting and utilization of this valuable medicinal flora, many plants are quickly going towards extinction;therefore, further work is needed to create awareness in the community conservation of the precious medicinal plants.

关键词： Ethnobotanical Study Medicinal Plants Makerwal & Gulla Khel Pakistan