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Phase Diagram Body-Centredof Catalytic Oxidation of CO on the Surface-Subsurface of a Body-Centred Cubic Structure with Eley-Rideal Process： A monte Carlo Simulation

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Chinese Physics Letters 2004年第9期21卷 1838-1841页

作者： AU.Qaisrani m.khalid musaKaleemBalocht DepartmentofPhysics GomalUniversityD.I.KhanPakistan DepartmentofChemistry GomalUniversityD.I.KhanPakistan

monte Carlo simulation is used to explore the effects of the Eley-Rideal (ER) process on the phase diagram of the Langmuir–Hinshelwood (LH) type monomer–dimer (CO–O2) catalytic reaction on the surface and subsurface of a body-centred cubic structure, which extends to only two layers in the z-direction. The dimer (O2) is adsorbed in such a way that it takes one surface site whereas the second site is from the subsurface. For this mechanism, an interesting situation develops. The production rate of CO2 is found to be consistent with experiment. The qualitative trend of the surface oxygen coverage is not consistent with the experimental situation in one model while it is found to be consistent with that in another model, i.e. the coverage of surface oxygen decreases slowly with increase of concentration of CO (yCO). moreover, the production of CO2 can be predicted in the form of a mathematical relation.

关键词： Phase diagrams

Non-Thermal Effects on CO-NO Surface Catalytic Reaction on Square Surface： monte Carlo Study

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Chinese Physics Letters 2005年第6期22卷 1533-1535页

作者： m.khalid A.U.Qaisrani W.Ahmad DepartmentofPhysics GomalUniversityDeraIsmailKhanPakistan PhysicsResearchDivision PakistanInstituteofNuclearScienceandTechnologyPONiloreIslamabadPakistan

A monte Carlo simulation of the CO–NO heterogeneous catalytic reaction over a square surface has already been studied with a model based on the Langmuir–Hinshelwood (LH) mechanism. The results of this study are well known. Here we study the effects of transient non-thermal mobility of monomer (CO) based on precursor mechanism, diffusion of adsorbed nitrogen and oxygen atoms, on the phase diagram. The interesting feature of this model is the yield of a steady reactive window, while simple LH mechanism is not capable of producing a steady reactive state.

关键词： FOPT SOPT CO ZGB

Dip Coating of Nano Hydroxyapatite on Titanium Alloy with Plasma Assistedγ-Alumina Buffer Layer:A Novel Coating Approach

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Journal of materials Science & Technology 2013年第6期29卷 557-564页

作者： m.khalid m.mujahid A.Nusair Khan R.S.Rawat School of Chemical and materials Engineering National University of Sciences and TechnologySector H-12IslamabadPakistan Institute of Industrial Control Systems RawalpindiPakistan NSSE National Institute of EducationNanyang Technological UniversitySingapore

This paper reported a novel coating approach to deposit a （HA） film on Ti6Al4V alloy with Al2O3 buffer layer for thin, crack free and nano-structured hydroxyapatite biomedical implants. The Al2O3 buffer layer was deposited by plasma spraying while the HA top layer was applied by dip coating technique. The X-ray diffraction （XRD） and Raman reflections of alumina buffer layer showed α- to γ-Al2O3 phase transformation; and the fractographic analysis of the sample revealed the formation of columnar grains in well melted splats. The bonding strength between Al2O3 coating and Ti6Al4V substrate was estimated to be about 40 mPa. The presence of dip coated HA layer was confirmed using XRD, scanning electron microscopy （SEm） and energy dispersive X-ray spectroscopy （EDX） analysis. The SEm images exhibited that HA top layer enveloped homogenously the troughs and crests of the underneath rough （Ra = 2.91 μm） Al2O3 surface. It is believed that the novel coating approach adopted might render the implant suitable for rapid cement-less fixation as well as biocompatible for longer periods.

关键词： Ti6Al4V alloy Biomaterials Buffer layer Ceramic coatings

Effect　of　Ballistic-Type　Hot　Atom　Adsorption　mechanism　on　the　Phase　Diagram　of　monomer　Dimer　CO-O2　Surface　Catalytic　Reaction：　A　monte　Carlo　Simulation

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Chinese Physics Letters 2004年第6期21卷 1171-1174页

作者： m.khalid K.m.Khan A.U.Qaisrani Q.N.malik DepartmentofPhysics GomalUniversityDeraIsmailKhanPakistan NuclearPhysicsDivision PakistanInstituteofNuclearScienceandTechnology(PINSTECH)P.O.NiloreIslamabadPakistan

We investigate the effect of the ballistic mechanism on the phase diagram using a square surface. While using this mechanism whenever an O2 molecule hits a randomly vacant selected site, the molecule breaks up into atomic form and then executes a ballistic flight. The paths of the two oxygen atoms are taken exactly to be opposite to each other, ***-parallel, and the ranges of the atoms are taken to be equal, *** may fly up to 1 or 1.414 or 2 of the atomic spacing from the site of impact. Four cases have been studied on the basis of the range of hot atoms. The range of the hot oxygen atoms executing a ballistic flight might be up to the first nearest neighbourhood (1 atomic spacing from the site of impact), the second nearest neighbourhood (1.414 atomic spacing from the site of impact), the third nearest neighbourhood (2 atomic spacing from the site of impact), known as cases a, b, and c, respectively, while for case d the range of the oxygen atoms executing the ballistic flight might be up to 1 atomic spacing or 1.414 atomic spacing or 2 atomic spacing from the site of impact. The steady reactive window is observed and the continuous transition disappears. As soon as the CO partial pressure departs from zero, the production of CO2 is observed, which clearly verifies the experimental observation.

关键词： Oxygen

Optimization Study of Pulsed DC Nitrogen-Hydrogen Plasma in the Presence of an Active Screen Cage

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Plasma Science and Technology 2014年第5期16卷 460-464页

作者： A.SAEED A.W.KHAN F.JAN H.U.SHAH m.ABRAR m.ZAKA-UI-ISLAm m.khalid m.ZAKAULLAH National Centre for Physics Quaid-i-Azam University Campus Islamabad Department of Physics Gomal University Department of Physics Quaid-i-Azam University Department of Physics Hazara University Mansehra Department of Physics Faculty of ScienceUniversity of Jazan

A glow discharge plasma nitriding reactor in the presence of an active screen cage is optimized in terms of current density,filling pressure and hydrogen concentrations using optical emission spectroscopy（OES）.The samples of AISI 304 are nitrided for different treatment times under optimum *** treated samples were analyzed by X-ray diffraction（XRD） to explore the changes induced in the crystallographic *** XRD pattern confirmed the formation of iron and chromium nitrides arising from incorporation of nitrogen as an interstitial solid solution in the iron lattice.A Vickers microhardness tester was used to evaluate the surface hardness as a function of treatment time（h）.The results showed clear evidence of improved surface hardness and a substantial amount of decrease in the treatment time compared with the previous work.

关键词： optical diagnostics plasma nitriding austenitic stainless steel

Review of pharmacologic and immunologic agents in the management of COVID-19

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Biosafety and Health 2021年第3期3卷 148-155页

作者： marzuq A.Ungogo mustapha mohammed Bala N.Umar Auwal A.Bala Garba m.khalid Department of Veterinary Pharmacology and Toxicology Ahmadu Bello UniversityZaria 810107Kaduna StateNigeria Institute of Infection Immunity and InflammationCollege of MedicalVeterinary and Life SciencesUniversity of GlasgowGlasgow G128TAUnited Kingdom School of Pharmaceutical Sciences Universiti Sains Malaysi1Penang City 11800Pulau Pinang StateMalaysia Department of Clinical Pharmacy and Pharmacy Practice Ahmadu Bello UniversityZaria 810107Kaduna StateNigeria Department of Veterinary microbiology Faculty of Veterinary MedicineAhmadu Bello UniversityZaria 810107Kaduna StateNigeria Department of Pharmacology College of Medicine and Health SciencesFederal UniversityDutse 720231Jigawa StateNigeria Faculty of Pharmaceutical Sciences Bayero UniversityKano P.M.B.3011Kano StateNigeria Department of Pharmaceutical Sciences UniversitàDegli Studi di MilanoVia G.Colombo71Milano 20133Italy

The novel coronavirus disease 2019(COVID-19)is the third coronavirus outbreak in the last two *** and re-emerging infections like COVID-19 pose serious challenges of the paucity of information and lack of specific cure or *** leaves utilisation of existing scientific data on related viral infections and repurposing relevant aetiologic and supportive therapies as the best control approach while novel strategies are developed and *** promising antiviral agents including lopinavir,ritonavir,remdesivir,umifenovir,darunavir,and oseltamivir have been repurposed and are currently trialled for the care for COVID-19 *** therapies for the management of symptoms and to provide support especially in severe and critically ill patients have also been *** review provides an appraisal of the current evidence for the rational use of frontline therapeutics in the management of *** also includes updates regarding COVID-19 immunotherapy and vaccine development.

关键词： SAR-CoV-2 COVID-19 Respiratory Drug repurposing Antiviral Supportive therapy Immunotherapy

Quantitative and Qualitative Responses of Hydroponic Tomato Production to Different Levels of Salinity

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Phyton-International Journal of Experimental Botany 2024年第6期93卷 1311-1323页

作者： khalid A.Al-Gaadi Ahmed m.Zeyada ElKamil Tola Abdullah m.Alhamdan khalid A.m.Ahmed Rangaswamy madugundu mohamed K.Edrris Department of Agricultural Engineering College of Food and Agriculture SciencesKing Saud UniversityRiyadh11451Saudi Arabia Precision Agriculture Research Chair Deanship of Scientific ResearchKing Saud UniversityRiyadh11451Saudi Arabia Chair of Dates Industry&Technology Deanship of Scientific ResearchKing Saud UniversityRiyadh11451Saudi Arabia Agricultural Research Centre Agricultural Engineering Research Institute(AEnRI)Giza12619Egypt

From economic and nutritional points of view,tomato is,historically,considered one of the most important *** signiﬁcant yield reduction,most commercial cultivars of tomato crops are sensitive to moderate levels of ***,high levels of salt stress can negatively affect the yield and quality of tomato ***,this study was conducted to evaluate the yield and fruit quality of three tomato cultivars(Forester,Ghandowra-F1,and Feisty-Red)cultivated hydroponically,under three different levels of nutrient solution *** of tomato fruits was performed based on quantity(number and weight of fruits,and total fruit yield),physical quality(color andﬁrmness),and chemical quality(refractometric index“Brix”,pH,EC,K^(+),Na^(+),and NO_(3)-).Experiments were conducted using three salinity levels of the nutrient solution with electrical conductivity values(dSm^(-1))of 2.5(control),6.0,and *** showed that the studied tomato cultivars were signiﬁcantly inﬂuenced by high salinity(9.5 dSm^(-1))in comparison to the low(2.5 dSm^(-1))and medium(6.0 dSm^(-1))levels of *** average,the highest fruit weight per plant of 1944.84 g and total fruit yield of 4.42 kgm^(-2) were observed at the low salinity level;however,no signiﬁcant differences were obtained in the two yield factors(single fruit weight and total fruit yield)for the low and medium salinity *** the other hand,a signiﬁcant reduction in tomato yield(31%)was associated with the high salinity level compared to the yield at low and medium salinity *** of physical quality parameters showed highly signiﬁcant differences among all salinity *** average,the maximum value of color change(1.72)was associated with the medium salinity level,and the maximum value ofﬁrmness(9.61 Ncm^(-1))was recorded at the high salinity *** levels and tomato cultivars introduced signiﬁcant differences in chemical quality parameters;however,no signiﬁcant differences in these

关键词： Quality cultivars yield color ﬁrmness brix

Existence results and behavior analysis for nonlinear age-dependent population dynamics problems with conformable fractional operator

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International Journal of Biomathematics 2024年第5期17卷 229-256页

作者： Hiba El Asraoui m'hamed El Omari Ali El mfadel khalid Hilal Laboratory of Applied mathematics Scientific Computing Sultan moulay Slimane University BP 523 Beni MellalMorocco

In this paper,we investigate the existence of solutions and analyze the large-time behavior for Gurtin-maccamy population model involving conformable fractional *** a preliminary step,we construct a generic structure of the solution associated with our proposed model by utilizing some basic properties and tools of conformable fractional *** establish the existence of a unique solution of the given model with the given initial *** last,by using the upper and lower solutions for the characteristic equation,we define the upper and lower boundaries for the obtained solution and describe the large-time behavior of the total population.

关键词： Age-dependent population conformable fractional operator upper and lower boundary of the solution dynamics of populations

A Comprehensive 3-Steps methodology for Vibration-Based Fault Detection,Diagnosis and Localization in Rotating machines

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Journal of Dynamics, monitoring and Diagnostics 2024年第1期3卷 49-58页

作者： khalid m.Almutairi Jyoti K.Sinha Dynamics Laboratory School of EngineeringThe University of ManchesterManchester M139PLUK

In any industry,it is the requirement to know whether the machine is healthy or not to operate machine *** the machine is not healthy then what is the fault in the machine and then finally its *** paper is proposing a 3-Steps methodology for the machine fault diagnosis to meet the industrial requirements to aid the maintenance *** Step-1 identifies whether machine is healthy or faulty,then Step-2 detect the type of defect and finally its location in *** method is extended further from the earlier study on the 2-Steps method for the rotor defects only to the 3-Steps methodology to both rotor and bearing *** method uses the optimised vibration parameters and a simple Artificial Neural Network(ANN)-based machine Learning(mL)model from the earlier *** model is initially developed,tested and validated on an experimental rotating rig operating at a speed above 1st critical *** proposed method and model are then further validated at 2 different operating speeds,one below 1st critical speed and other above 2nd critical *** machine dynamics are expected to be significantly different at these *** highlights the robustness of the proposed 3-Steps method.

关键词： bearing faults fault diagnosis machine learning rotating machines rotor faults vibration analysis