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Non-axisymmetric Homann stagnation-point flow of Walter’s B nanofluid over a cylindrical disk

Applied mathematics and mechanics(English Edition) 2020年第5期41卷 725-740页

作者： m.KHAN m.sarfraz J.AHmED L.AHmAD C.FETECAU Department of mathematics Quaid-i-Azam UniversityTaxila 47050Pakistan Department of Basic Sciences University of Engineering and TechnologySheringal Upper Dir 18000Pakistan Department of mathematics Shaheed Benazir Bhutto UniversitySheringal Upper Dir 18000Pakistan Academy of Romanian Scientists Bucuresti 050094Romania

The study of non-axisymmetric Homann stagnation-point flow of Walter’s B nanofluid along with magnetohydrodynamic(mHD) and non-linear Rosseland thermal radiation over a cylindrical disk in the existence of the time-independent free stream is considered. moreover, the notable impacts of thermophoresis and Brownian motion are analyzed by Buongiorno’s model. The momentum, energy, and concentration equations are converted into the dimensionless coupled ordinary differential equations via similarity transformations, which are later numerically solved by altering the values of the pertinent parameters. The numerical and asymptotic solutions for the large shear-to-strain rate ratio γ =a/bfor the parameters of the displacement thicknesses and the wall-shear stress are computed by perturbative expansion and analyzed. Furthermore, the technique bvp4c in mATLAB is deployed as an efficient method to analyze the calculations for the non-dimensional velocities, temperature, displacement thickness, and concentration profiles. It is observed that the two-dimensional displacement thickness parameters α andβ are reduced due to the viscoelasticity and magnetic field effects. moreover, when the shear-to-strain rate ratio approaches infinity, α is closer to its asymptotic value, while βand the three-dimensional displacement thickness parameter δ1 show the opposite *** outcomes of the viscoelasticity and the magnetic field on the skin friction are also determined. It is concluded that ■ reaches its asymptotic behavior when the shearto-strain rate ratio approaches infinity. meanwhile, ■ shows different results.

关键词： Walter’s B fluid cylindrical disk nanofluid magnetic field non-linear thermal radiation stagnation-point flow

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Non-axisymmetric Homann mHD stagnation point flow of Al2O3-Cu/water hybrid nanofluid with shape factor impact

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Applied mathematics and mechanics(English Edition) 2020年第8期41卷 1125-1138页

作者： m.KHAN J.AHmED F.SULTANA m.sarfraz Department of mathematics Quaid-i-Azam UniversityIslamabad 44000Pakistan Department of Basic Sciences University of Engineering and TechnologyTaxila 47050Pakistan

The heat transfer of Homann flow in the stagnation region of the Al2 O3-Cu/water hybrid nanofluid is investigated by adopting the Tiwari-Das model over a cylindrical *** effects of the nanoparticle shape,the viscous dissipation,and the nonlinear radiation are *** governing equations are obtained by using similarity transformations,and the numerical outcomes for the flow and the temperature field are noted by bvp4 c on *** numerical solutions of the flow field are compared with the asymptotic behaviors of large shear-to-strain-rate *** effects of variations of parameters involved are inspected for both nanofluid and hybrid nanofluid flows,temperature profiles,local Nusselt numbers,and skin *** is concluded that the velocity and temperature fields in the hybrid nanophase function more rapidly than those in the nanofluid phase.

关键词： cylindrical disk hybrid nanofluid magnetic field non-linear thermal radiation stagnation point flow viscous dissipation

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metal Contamination in Nullah Dek Water and Accumulation in Rice

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Pedosphere 2007年第1期17卷 130-136页

作者： m.sarfraz S.m.mEHDI G.HASSAN S.T.ABBAS Plant Nutrition Division Soil Salinity Research InstitutePindi Bhattian(Pakistan) Crop Sciences Institute National Agricultural Research Centre(NARC)Islamabad (Pakistan)

A research study was carried out to determine the electrical conductivity (EC), residual sodium carbonate (RSC), sodium adsorption ratio (SAR), pH and metals in metal-polluted irrigation water from a nullah and those in soils over a period of time, and the effect of metals on rice yield and metal concentrations in rice grain and straw. Two sites (I and II) were selected on the bank of Nullah Dek at Thatta Wasiran in Sheikhupura District (Pakistan), with two rice varieties, Super Basmati and Basmati 385, at both sites. Water samples were collected during rice crop growth at 15-day intervals from August 3 to November 1, 2002. The results showed that Nullah Dek water had an EC >1.0 dS m-1 and RSC of 2.78-4.11 mmolc L-1, which was hazardous for crops, but the SAR was within the safe limit. Cu, mn Cd and Sr were also within safe limits. The soil analysis showed that Site II was free from salinity/sodicity, whereas Site I was saline sodic. Among metals, Zn was sometimes deficient, Cu, mn and Fe were adequate, and Sr, Ni and Cd were within safe limits in the soil at both the sites. After the rice crop harvest, concentrations of all metals tested were usually slightly increased, being higher in the upper soil layer than the lower. In addition, Basmati 385 produced higher rice grain and straw yield than Super Basmati. Chemical analysis of rice grain indicated the presence of Zn, Cu, Fe, mn, Pb and Sr, whereas rice straw contained Zn, Cu, Fe, mn and Sr, with Cd and Ni both being found in minute quantities.

关键词：金属混合物小麦水路浇灌技术

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A New Transplanting Approach to Enhance Salt Tolerance of Tree Saplings

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Pedosphere 2004年第1期14卷 77-84页

作者： S.m.mEHDI G.HASSAN A.H.SHAH m.sarfraz m.SADIQ Soil Salinity Research Institute (SSRI) Pindi Bhattian (Pakistan).Soil Salinity Research Institute (SSRI) Pindi Bhattian (Pakistan).International Waterlogging and Salinity Research Institute Lahore (Pakistan)Soil Salinity Research Institute (SSRI) Pindi Bhattian (Pakistan).Soil Salinity Research Institute (SSRI) Pindi Bhattian (Pakistan).

A field investigation was conducted to determine the survival and growth rate of eucalyptus (Eucalyptus camaldulensis Dehn.) and guava (Psidium guajava L.) saplings planted in salt-affected soils. The field used was highly saline-sodic in nature with a wide variation in electrical conductivity of the saturated soil extract (ECe), pHs, sodium adsorption ratio (SAR) and gypsum requirement (GR). A randomized complete block design was utilized with three treatments, i.e. T1 = plastic container bags totally removed, T2 = only the plastic container bag's base removed and T3 = plastic container bags un-removed. There were 34 and 8 plants in each block for eucalyptus and guava, correspondingly. The survival rates of eucalyptus and guava saplings were greater than 90%. In addition, gain in eucalyptus height was significantly higher in the T1 treatment where the bags were totally removed while for guava height the treatments were not *** gain in girth was not significant for both eucalyptus and guava saplings. With eucalyptus the taproot length was greater than the lateral roots while for guava the lateral roots were longer than the *** was a decrease in the salinity-sodicity of the soils for the upper 30 cm depth under both types of vegetation, indicating that the salts had leached down to the B-horizon.

关键词：树苗桉树番石榴盐份移栽机具传导性 pH值吸附率

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Al3+ doped CeO2 for proton conducting fuel cells

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International Journal of minerals,metallurgy and materials 2024年第10期31卷 2253-2262页

作者： sarfraz Shahzad Rasool muhammad Khalid m.A.K.Yousaf Shah Bin Zhu Jung-Sik Kim muhammad Imran Asghar Nabeela Akbar Wenjing Dong Jiangsu Provincial Key Laboratory of Solar Energy Science and Technology/Energy Storage joint Research Center School of Energy and Environment Southeast University Sino-French Engineer School/School of General Engineering Beihang University Renewable Energy Technologies Group Faculty of Engineering and Natural Sciences Tampere University School of microelectronics Hubei University

Developing high ionic conducting electrolytes is crucial for applying proton-conducting fuel cell （PCFCs） *** current study investigates the effect of alumina on the structural,morphological,electrical,and electrochemical properties of *** oxygen vacancies are induced in CeO2by a general doping concept that enables fast ionic conduction at low-temperature ranges（300–500°C） for *** refinement of the X-ray diffraction （XRD） patterns established the pure cubic fluorite structure of Aldoped CeO2（ADC） samples and confirmed Al ions’fruitful integration in the *** electronic structure of the alumina-doped ceria of the materials （10ADC,20ADC,and 30ADC） has been *** a result,it was found that the best composition of 30ADC-based electrolytes induced maximum lattice oxygen *** corresponding PCFC exhibited a maximum power output of 923 mW/cm2at 500°***,the investigation proves the proton-conducting ability of alumina-doped ceria-based fuel cells by using an oxide ion-blocking layer.

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Water-stable ZIF-300/Ultrason? mixed-matrix membranes for selective CO_2 capture from humid post combustion flue gas

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Chinese Journal of Chemical Engineering 2018年第5期26卷 1012-1021页

作者： muhammad sarfraz m. Ba-Shammakh Department of Polymer and Process Engineering University of Engineering and Technology Lahore 54890 Pakistan Department of Chemical Engineering King Fahd University of Petroleum and Minerals Dhahran 31261 Saudi Arabia

Water stable mixed-matrix membranes(mmms) were developed to help control the global warming by capturing and sequestrating carbon dioxide(CO_2) from post-combustion flue gas originated from burning of fossil *** of different compositions were prepared by doping glassy polymer Ultrason? S 6010(US) with nanocrystals of zeolitic imidazolate frameworks(ZIF-300) in varying degrees. Solution-casting technique was used to fabricate various mmms to optimize their CO_2 capturing performance from both dry and wet gases. The prepared composite membranes indicated enhanced filler-polymer interfacial adhesion, consistent distribution of nanofiller, and thermally established matrix configuration. CO_2 permeability of the membranes was enhanced as demonstrated by gas sorption and permeation experiments performed under both dry and wet conditions. As compared to neat Ultrason? membrane, CO_2 permeability of the composite membrane doped with 40 wt% ZIF-300 nanocrystals was increased by four times without disturbing CO_2/N_2 ideal selectivity. In contrast to majority of previously reported membranes, key features of the fabricated mmms include their structural stability under humid conditions coupled with better and unaffected gas separation performance.

关键词：烟道气体混合矩阵 CO2 燃烧潮湿马厩膜柱子

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A Seismic Hazard map Based on Geology and Shear-wave Velocity in Rawalpindi–Islamabad,Pakistan

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Acta Geologica Sinica(English Edition) 2021年第2期95卷 659-673页

作者： sarfraz KHAN muhammad WASEEm m.Asif KHAN National Centre of Excellence in Geology University of Peshawar 25130KPPakistan University of Peshawar 25120 KPPakistan

The‘twin cities’district of Rawalpindi–Islamabad is among the most endangered seismic regions in Pakistan,with the seismic hazard assessed(0.32 g)to intensity IX mmI for a 475-year return period.A seismic hazard map for Rawalpindi–Islamabad is presented herein,based on 85 shear-wave velocity(VS)profiles obtained through geophysical H/V measurements and from the geological map of the *** between the average top thirty-meter shear-wave velocities(VS30)and surficial geological units have been *** peak ground acceleration(PGA)maps for 150,475 and 2475-year return periods were converted into a seismic intensity *** increments for different soils were used to compute PGA values for 150,475 and 2475-year return *** located on softer ground experienced a higher degree of damage from moderate *** to the presence of soft clay or liquefiable soil and lateral spreading,a few locations may be classified as hybrid sites class C and *** map is a critical step in facilitating code-based site classification and seismic design throughout Rawalpindi–*** the seismic hazard map based on seismic intensities is no longer used in engineering geology,it is still important in seismological analysis and for civil protection purposes.

关键词： seismic hazard site classification intensity increment engineering geology Rawalpindi-Islamabad

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Parallel propagating modes and anomalous spatial damping in the ultra-relativistic electron plasma with arbitrary degeneracy

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Chinese Physics B 2017年第11期26卷 76-82页

作者： H Farooq m.sarfraz Z Iqbal G Abbas H A Shah Department of Physics Government College University Government College University

The dispersion relations of parallel propagating modes（Langmuir mode, right and left handed circular polarized waves） in the weak magnetic field limit ｜ω-k·v｜〉〉？ are considered for ultra-relativistic arbitrary degenerate electron plasma. The results are presented in terms of moments of Fermi-Dirac distribution. The increase in the electron equilibrium number density from negative large（weakly degenerate） to positive large（highly degenerate） values of μ/Te is observed（where μ is the electron chemical potential and Te is the electron thermal energy）. As a result, shifting of the cutoff points in all the real dispersion branches towards the higher values and increasing in the band gap between unmagnetized longitudinal and transverse modes in k-space are examined. Also, the suppression of the weak magnetic field effects in weakly magnetized right handed and left handed circular polarized waves and a decrease in the longitudinal and transverse screening effects are observed in the graphical patterns due to an increase in the equilibrium number density.

关键词： degenerate Fermi gases relativistic plasmas electromagnetic waves

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Study of Bacterial Samples Using Laser Induced Breakdown Spectroscopy

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Plasma Science and Technology 2014年第12期16卷 1141-1146页

作者： W A FAROOQ m ATIF W TAWFIK m S ALSALHI Z A ALAHmED m.sarfraz J P SINGH Physics and Astronomy Department College of ScienceKing Saud UniversityRiyadh 11451Saudi Arabia National Institute of Laser and Optronics NiloreIslamabadPakistan National Institute of Laser Enhanced Sciences NILES Department of Environmental ApplicationsCairo UniversityCairoEgypt Sustainable Energy Technologies Centre King Saud UniversityRiyadhSaudi Arabia Institute for Clean Energy Technology Mississippi State UniversityStarkvilleMS 39759USA

Laser-induced breakdown spectroscopy （LIBS） technique has been applied to inves- tigate two different types of bacteria, Escherichia coli （B1） and micrococcus luteus （B2） deposited on glass slides using Spectrolaser 7000. LIBS spectra were analyzed using spectrolaser software. LIBS spectrum of glass substrate was compared with bacteria spectra. Ca, mg, Na, K, P, S, C1, Fe, A1, mn, Cu, C, H and CN-band appeared in bacterial samples in air. Two carbon lines at 193.02 nm, 247.88 nm and one hydrogen line at 656.28 nm with intensity ratios of 1.9, 1.83 and 1.53 appeared in bacterial samples B1 and B2 respectively. Carbon and hydrogen are the important components of the bio-samples like bacteria and other cancer cells. Investigation on LIBS spectra of the samples in He and Ar atmospheres is also presented. Ni lines appeared only in B2 sample in Ar atmosphere. From the present experimental results we are able to show that LIBS technique has a potential in the identification and discrimination of different types of bacteria.

关键词： laser induced breakdown bacteria bio-samples and carbon lines

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Impact of grazing on soil, vegetation and ewe production performances in a semi-arid rangeland

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Journal of mountain Science 2018年第4期15卷 685-694页

作者： muhammad ISLAm Abdul RAZZAQ Shamim GUL sarfraz AHmAD Taj mUHAmmAD Sawsan HASSAN Barbara RISCHKOWSKY m.N.m.IBRAHIm mounir LOUHAICHI International Center for Agricultural Research in Dry Areas (ICARDA) South Asia Islamabad Pakistan Animal Sciences Division Pakistan Agricultural Research Council Islamabad Pakistan Botany Department University of Balochistan Quetta Pakistan Department of Natural Resource Sciences McGill University QC Canada Natural Resources Division Pakistan Agricultural Research Council Islamabad Pakistan Forest & Wildlife Department Quetta Balochistan Pakistan International Center for Agricultural Research in Dry Areas (ICARDA) Amman Jordan International Center for Agricultural Research in Dry Areas (ICARDA) SSA ILRI campus Addis Ababa Ethiopia International Livestock Research Institute (ILRI) Pakistan

Controlled grazing is considered a good management strategy to maintain or increase the live weight of livestock and to reduce vegetation degradation of rangelands. The present study investigated soil characteristics, aboveground vegetation biomass dynamics and controlled grazinginduced changes in the live weight of local ewes in the semi-arid rangeland of Ahmadun, Ziarat, Balochistanprovince of Pakistan. An area of 115 ha was protected from livestock grazing in April 2014. In June 2015, soil characteristics within 0-30 cm depth i.e. soil organic matter(SOm), mineral nitrogen, p H and texture in controlled and uncontrolled grazing sites were assessed. Aboveground vegetation biomass measured in early(June) and late summer(August) in 2015 and 2016. The nutritional value i.e. crude protein, phosphorus(P), neutral detergent fiber(NDF), acid detergent fiber(ADF), calcium(Ca), magnesium(mg) and potassium(K) of dominantplant species were assessed at the beginning of experiment in 2015. Vegetation cover of controlled and uncontrolled grazing sites was also measured during the two years of the study period using the Veg measure software. From June to November in2015 and 2016, controlled and uncontrolled livestock grazing sites were grazed on a daily basis by local ewes with a stocking rate of 2 and 1 head ha^(-1) respectively. Results reveal that the organic matter contents of coarse-textured, slightly alkaline soil of the study site were in the range of 9.4-17.6 g kg^(-1) soil and showed a strong positive correlation with aboveground vegetation biomass. The biomass of plants was 56.5% and 33% greater at controlled than uncontrolled grazing site in 2015 and 2016 respectively and plant cover was also higher at controlled than uncontrolled grazing site in both years The nutrient contents were significantly(Pmpared to the uncontrolled *** results

关键词：土壤特征放牧地生产率半干旱植被牧场生物资源土壤有机物

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