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Applied Mathematics(A Journal of Chinese Universities) 2024年第1期39卷 34-46页

作者： ZHOU Shuang-shuang Muhammad Ijaz Khan Sami Ullah Khan suma.r. qayyum School of Science Hunan City UniversityYiyang 413000China Department of Mechanical Engineering Prince Mohammad Bin Fahd UniversityP.O.Box1664Al-Khobar 31952Kingdom of Saudi Arabia Department of Mathematics Namal UniversityMianwali 42250Pakistan Department of Mathematics Quaid-I-Azam University 45320Islamabad 44000Pakistan

The investigation endorsed the convective flow of Carreau nanofluid over a stretched surface in presence of entropy generation *** novel dynamic of viscous dissipation is utilized to analyze the thermal mechanism of magnetized *** convective boundary assumptions are directed in order to examine the heat and mass transportation of *** thermal concept of thermophoresis and Brownian movements has been re-called with the help of Buongiorno *** problem formulated in dimensionless form is solved by NDSolve *** graphical analysis for parameters governed by the problem is performed with physical *** affiliation of entropy generation and Bejan number for different parameters is inspected in *** numerical data for illustrating skin friction,heat and mass transfer rate is also *** motion of the fluid is highest for the viscosity ratio *** temperature of the fluid rises via thermal Biot *** generation rises for greater Brinkman number and diffusion parameter.

关键词： heat generation surface reaction CNTs based nano uid stretching/shrinking sheet thermal radiation

Barley chitinase genes expression revamp resistance against whitefly (Bemisia Tabaci) in transgenic cotton (Gossypium hirsutum L.)

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Journal of Cotton research 2024年第1期7卷 90-100页

作者： BASHIr Samina YAQOOB Amina BASHIr rohina BUKHArI Shanila SHAHID Naila AZAM Saira BAKHSH Allah HUSNAIN Tayyab SHAHID Ahmad Ali rAO Abdul qayyum Centre of Excellence in Molecular Biology University of the PunjabLahore 53700Pakistan Department of Botany Kinnaird College for Women UniversityLahore 54000Pakistan Department of Botany Government College UniversityFaisalabad 38000Pakistan Institute of Botany University of the PunjabLahore 54590Pakistan.

Background Chitinase is an enzyme that hydrolyzes chitin,a major component of the exoskeleton of insects,including plant pests like *** present study aimed to investigate the expression of chemically synthesized barley ch1 and chi2 genes in cotton(Gossypium hirsutum)through Agrobacterium-mediated ***-five putative transgenic cotton plants were obtained,out of which fifteen plants successfully survived and were shifted to the *** gene-specific primers,amplification of 447 bp and 401 bp fragments confirmed the presence of the ch1 and chi2 genes in five transgenic cotton plants of the T0 *** five plants were further evalu-ated for their mrNA expression *** T0 transgenic cotton plants with the highest mrNA expression level and better yield performance in field,were selected to raise their subsequent *** The T1 cotton plants showed the highest mrNA expression levels of 3.5-fold in P10(2)for the ch1 gene and 3.7-fold in P2(1)for the chi2 *** in situ hybridization(FISH)confirmed a single copy number of ch1 and chi2(hemizygous)on chromosome ***,the efficacy of transgenes on whitefly was evaluated through an insect bioassay,where after 96 h of infestation,mortality rates of whitefly were calculated to be 78%–80%in transgenic cotton *** number of eggs on transgenic cotton plants were calculated to be 0.1%–0.12 per plant compared with the non-transgenic plants where egg number was calculated to be 0.90–1.00 per *** Based on these findings,it can be concluded that the chemically synthesized barley chitinase genes(ch1 and chi2)have the potential to be effective against insects with chitin exoskeletons,including *** transgenic cotton plants expressing these genes showed increased resistance to whiteflies,resulting in reduced egg numbers and higher mortality rates.

关键词： Chitinase Cotton White fly Transgene Bioassay

Catalyzed degradation of disperse dyes by calcium alginate-pectin entrapped bitter gourd (Momordica charantia) peroxidase

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Journal of Environmental Sciences 2011年第7期23卷 1135-1142页

作者： rukhsana Satarn qayyum Husai Department of Biochemistry Faculty of Life Sciences Aligarh Muslim University Faculty of Applied Medical Sciences Jazan University Jazan

Calcium-alginate pectin entrapped bitter gourd peroxidase （BGP） has been employed for the treatment of disperse dyes： Disperse Brown 1 （DB 1） and Disperse red 17 （Dr 17）. Peroxidase alone was unable to decolorize Dr 17 and DB 1. However, the investigated dyes were decolorized maximally by BGP in the presence of 0.2 mmol/L redox mediator, violuric acid （VA）. A slow decrease in percent decolorization was observed when VA concentration was higher than 0.2 mmol/L which could likely be due to the high reactivity of its aminoxyl radical （ N–O . ） intermediate, that might undergo chemical reactions with aromatic amino acid side chains of the enzyme thereby inactivating it. Maximum decolorization of the dyes was observed at pH 3.0 and 40°C within 2 hr of incubation. Immobilized peroxidase decolorized 98% Dr 17 and 71% DB 1 using 35 U of BGP in batch process in 90 min. Immobilized enzyme decolorized 85% Dr 17 and 51% DB 1 whereas soluble enzyme decolorized Dr 17 to 48% and DB 1 to 30% at 60°C. UV-visible spectral analysis was used to evaluate the degradation of these dyes and their toxicity was tested by Allium cepa test. The generally observed higher stability of the bioaffinity bound enzymes against various forms of inactivation may be related to the specific and strong binding of enzyme with bioaffinity support which prevents the unfolding/denaturation of enzyme. Thus entrapped peroxidase was found to be effective in the decolorization of the investigated dyes.

关键词： bitter gourd peroxidise (BGP) alginate pectin decolorization disperse dyes

Potential of plant polyphenol oxidases in the decolorization and removal of textile and non-textile dyes

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Journal of Environmental Sciences 2007年第4期19卷 396-402页

作者： AMJAD ALI Khan qayyum Husain Department of Biochemistry Faculty of Life Science Aligarh Muslim UniversityAligarh-202 002India.

In this study an effort has been made to use plant polyphenol oxidases; potato （Solanum tuberosum） and brinjal （Solanum melongena）, for the treatment of various important dyes used in textile and other industries. The ammonium sulphate fractionated enzyme preparations were used to treat a number of dyes under various experimental conditions. Majority of the treated dyes were maximally decolorized at pH 3.0. Some of the dyes were quickly decolorized whereas others were marginally decolorized. The initial first hour was sufficient for the maximum decolorization of dyes. The rate of decolorization was quite slow on long treatment of dyes. Enhancement in the dye decolorization was noticed on increasing the concentration of enzymes. The complex mixtures of dyes were treated with both preparations of polyphenol oxidases in the buffers of varying pH values. Potato polyphenol oxidase was significantly more effective in decolorizing the dyes to higher extent as compared to the enzyme obtained from brinjal polyphenol oxidase. Decolorization of dyes and their mixtures, followed by the formation of an insoluble precipitate, which could be easily removed simply by centrifugation.

关键词： decolorization textile dyes polyphenol oxidases potato brinjal wastewater treatment removal of dyes

Improvements in methodology to determine feedback reactivity coefficients

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Nuclear Science and Techniques 2019年第4期30卷 91-104页

作者： Faisal qayyum Muhammad rizwan Ali Awais Zahur r.Khan Department of Nuclear Engineering Pakistan Institute of Engineering and Applied Sciences (PIEAS) Department of Nuclear Engineering Pakistan Institute of Engineering and Applied Sciences(PIEAS)

The reactivity of a nuclear reactor is the most important safety and operating parameter. Due to short reactor period, the Light Water reactor(LWr) designs require the compensations of rapid unfavorable reactivity increases. The increase in fuel or moderator temperature leads to compensate the reactivity jumps as inherent safety characteristics. The safe and reliable reactor operation requires the accurate assessment of these reactivity changes. This paper highlights the improvements in the methodology to determine the feedback reactivity changes in IAEA MTr benchmark. This method incorporates the reactivity effects of fuel temperature in moderator regions and vice versa. For this purpose, a detailed 3D model of the IAEA 10 MW MTr benchmark reactor is developed employing OpenMC computer code. OpenMC is a probabilistic computer code for neutronic calculations. This work uses temperature-dependent JEFF 3.2 cross-sectional library. The model is validated against the reference results of eigenvalues for control rods(inserted and in fully withdrawn position), control rod reactivity worth, averaged thermal flux in the central flux trap, and power fraction for each fuel element at beginning of life. The validated model is applied to simulate the feedback reactivity coefficients against the conventional reference results. In order to improve the methodology, the effect of the moderator temperature and void on fuel is incorporated to obtain a more realistic value of the fuel temperature ***, the moderator temperature coefficient and void coefficient are improved by incorporating the coupling effects of fuel temperature on moderator. This methodology can be applied to improve the LWr designs.

关键词： OpenMC MTr benchmark reactivity feedback coefficients Fuel temperature coefficient Moderator temperature coefficient Void coefficient of reactivity

Polarization multiplexing based duplex radio-over-fiber link for millimeter wave signal transmission to a ring of multiple radio access units

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Frontiers of Information Technology & Electronic Engineering 2019年第2期20卷 300-306页

作者： Tayyab MEHMOOD Hina qayyum Salman GHAFOOr School of Electrical Engineering and Computer Science National University of Sciences and Technology

A radio-over-fiber(roF) distributed antenna system(DAS) architecture is proposed, where millimeter wave(mm-wave) signals are transmitted to four different radio access units(rAUs) arranged in a ring *** proposed architecture transmits duplex data of 128 Mb/s to each rAU in both downlink(DL) and uplink(UL)directions. The radio frequency(rF) signals are transmitted by polarization multiplexing a multi-wavelength ***-wave signals at a frequency of 25 GHz are generated at each rAU using remote heterodyne *** proposed architecture provides increased coverage while maintaining good bit error rate(BEr) results.

关键词： radio over fiber Millimeter wave radio access units

Three-dimensional mixed convection squeezing flow

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Applied Mathematics and Mechanics(English Edition) 2015年第1期36卷 47-60页

作者： T.HAYAT A.qayyum A.ALSAEDI Department of Mathematics Quaid-i-Azam University Nonlinear Analysis and Applied Mathematics (NAAM) research Group Faculty of Science King Abdulaziz University

The unsteady mixed convection squeezing flow of an incompressible Newtonian fluid between two vertical parallel planes is discussed. The fluid is electrically conducting. The governing equations are transformed into ordinary differential equations （ODEs） by appropriate transformations. The transformed equations are solved successfully by a modern and powerful technique. The effects of the emerging parameters on the flow and heat transfer characteristics are studied and examined. The values of the skin friction coefficient and the local Nusselt number are tabulated and analyzed.

关键词： squeezing flow, mixed convection, vertical rotating channel unsteadystretching porous sheet

Development of multi-physics numerical simulation model to investigate thermo-mechanical fatigue crack propagation in an autofrettaged gun barrel

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Defence Technology（防务技术） 2021年第5期17卷 1579-1591页

作者： Naveed Hussain Faisal qayyum riffat Asim Pasha Masood Shah Department of Mechanical Engineering University of Engineering and TechnologyTaxilaPakistan Institut für Metallformung Technische Universitat BeragakademieFreibergGermany

In this research,a detailed multi-physics study has been carried out by numerically simulating a solid fractured gun barrel for 20 thermo-mechanical *** numerical model is based on thermal effects,mechanical stress fields and fatigue crack ***-plastic material data of modified AISI 4340 at temperatures ranging from 25 to 1200℃and at strain rates of 4,16,32 and 48 s^(-1) was acquired from high-temperature compression *** was used as material property data in the simulation *** boundary conditions applied are kept similar to the working gun barrel during continuous firing.A methodology has been provided to define thermo-mechanically active surface-to-surface type interface between the crack faces for a better approximation of stresses at the crack *** of results from non-autofrettaged and autofrettaged simulation models provide useful information about the evolution of strains and stresses in the barrel at different points under combined thermo-mechanical loading cycles in both *** effect of thermal fatigue under already induced compressive yield due to autofrettage and the progressive degradation of the accumulated stresses due to thermo-mechanical cyclic loads on the internal surface of the gun barrel(mimicking the continuous firing scenario)has been *** between energy release rate at tips of varying crack lengths due to cyclic thermo-mechanical loading in the non-autofrettaged and autofrettaged gun has been carried out.

关键词： Steel Autofrettage Gun barrel Crack propagation Thermo-mechanical fatigue Numerical simulation residual stress dissipation

Electrical and optical measurements in the early hydrogen discharge of GLAST-Ⅲ

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Plasma Science and Technology 2017年第8期19卷 66-75页

作者： S HUSSAIN A qayyum Z AHMAD S AHMAD r KHAN M A NAVEED r ALI F DEEBA G M VOrOBYOV GLAST Team National Tokamak Fusion Program 3329 Islamabad Pakistan Saint-Petersburg State University 198504 Saint-Petersburg Russia

This work presents the first electrical and optical measurements of the initial phase of hydrogen discharge in the upgraded spherical tokamak GLAST-III, initiated with electron cyclotron heating（ECH）. Diagnostic measurements provide insights into expected and unexpected physics issues related to the initial phase of discharge. A triple Langmuir probe（TLP） has been developed to measure time series of the floating potential, plasma electron temperature and number density over the entire discharge, allowing monitoring of the two phases of the discharge： the ECH pre-ionization phase following by the plasma current formation phase. A TLP has the ability to give time-resolved measurements of the floating potential（V_（float））, electron temperature（T_e） and ion saturation current（I_（sat）∝n_e√kT_e）.sat e eThe evolution of the ECH-assisted pre-ionization and subsequent plasma current phases in one shot are well envisioned by the probe. Intense fluctuations in the plasma current phase advocate for efficient equilibrium and feedback control systems. Moreover, the emergence of some strong impurity lines in the emission spectrum, even after only a few shots, suggests a crucial need for improvements in the base vacuum level. A noticeable change in the shape of the temporal profiles of the floating potential, electron temperature, ion saturation current（I_（sat）） and light emission has been observed with changing hydrogen fill pressure and vertical magnetic field.

关键词： floating saturation subsequent spherical heating triple unexpected impurity noticeable advocate

Surface-Induced Dissociation of Low Energy H_2^(+) Impact on a Carbon Surface: A Monte Carlo Simulation

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Communications in Theoretical Physics 2011年第2期55卷 315-320页

作者： Shakir Ullah A.H.Dogar A.qayyum Physics Division Pakistan Institute of Nuclear Science and Technology

A Monte Carlo simulation based on the classical binary collision approximation is performed to investigate the interaction of W2 ions with the carbon target. The incident H2^＋ ion is characterized by its translational energy, eigenenergy and population of the vibrational state, and orientation of the ion with respect to the target surface. It is shown that experimentally determined energy resolved mass spectrum of H＋ can be nicely reproduced with the help of the proposed model. These simulations predict that translational to vibrational （T → V） energy transfer efficiency increases nonlinearly with translational energy of the incident ion. T → V energy transfer efficiency along with the initial vibrational energy of the incident H＋ ion found to play an important role in dissociation. Our simulations also show that the fraction of absorbed, reflected, and dissociated ions depends on the translational energy. The average vibrational energy of reflected H＋ increases with its initial translational energy. Moreover, average number of collisions required for dissociation varies inversely with the initial translational energy of the H2^＋.

关键词： ion-surface collisions surface-induced dissociation hydrogen molecular ions Monte Carlo simulation