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Influence of rainfall infiltration on the stability of unsaturated coal gangue accumulated slope

Journal of Mountain Science 2021年第6期18卷 1696-1709页

作者： Kaleem Ullah jan khan WANG Chang-ming muhammad wasim jan khan LIANG Zhu LI Shuo LI Bai-long College of Construction Engineering Jilin UniversityChangchun 130021China Department of Management Sciences University College of Zhob(Sub-Campus BUITEMS)Balochistan 85200Pakistan

The slope instability is associated with increasing rate of rainfall infiltration which cause shear strength reduction and suction loss and the slope tend to failure. The influences of rainfall infiltration on the stability of clayey and sandy slopes have been analyzed but the effect of rainfall infiltration on the stability of unsaturated coal gangue accumulated slope was needed to study. Therefore, a coal gangue accumulated slope prone to failure in Fuxin area of Northeast China was considered to evaluate its failure mechanism under different rainfall events. The effects after five different rainfall events on slope stability were physically analyzed, numerically investigated and the results from both uncoupled(hydraulic) and coupled(hydromechanical) responses were compared using finite element analysis. It was observed that the decisive soaking and leaching under different rainfall conditions caused maximum deformation at the crest of slope due to maximum value of permeability coefficient of coal gangue. The critical duration of moderate intensity(147 mm/day) of rainfall for the instability of coal gangue accumulated slope is declared as five days. The results from finite element analysis in this paper further clarifies that increase in duration of rainfall infiltration process cause hysteretic change in positive pore-water pressure causing decrease in factor of safety and increase in deformation. It is concluded that the stability of unsaturated coal gangue accumulated slope is greatly influence by the coupled effect of stress and porewater pressure in comparison of uncoupled(hydraulic) analysis as the obtained factor of safety values after five days of rainfall infiltration were 0.9 and 1.1 respectively.

关键词： Hydro mechanical coupling Factor of safety Ground water table Rainfall infiltration Matric suction Coal gangue

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Airship aerodynamic model estimation using unscented Kalman filter

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Journal of Systems Engineering and Electronics 2020年第6期31卷 1318-1329页

作者： wasim muhammad ALI Ahsan Department of Electrical Engineering University of Engineering and TechnologyTaxila 47080Pakistan

An airship model is made-up of aerostatic,aerodynamic,dynamic,and propulsive forces and *** others,the computation of aerodynamic forces and torques is ***,wind tunnel experimentation and potential flow theory are used for their ***,the limitations of these methods pose difficulties in their accurate *** this work,an online estimation scheme based on unscented Kalman filter(UKF)is proposed for their *** proposed method introduces six auxiliary states for the complete aerodynamic *** uses an extended model and provides an estimate of a complete state vector along with auxiliary *** proposed method uses the minimum auxiliary state variables for the approximation of the complete aerodynamic model that makes it computationally less *** estimation performance is evaluated by developing a nonlinear simulation environment for University of Engineering and Technology,Taxila(UETT)*** performance is vali􀅫dated by performing the error analysis based on estimation error and 2-σ uncertainty *** the same problem,the extended Kalman filter(EKF)is also implemented and its results are compared with *** simulation results show that UKF successfully estimates the forces and torques due to the aerodynamic model with small estimation error and the comparative analysis with EKF shows that UKF improves the estimation re􀅫sults and also it is more suitable for the under-consideration problem.

关键词： airship unscented Kalman filter(UKF) extend Kalman filter(EKF) state estimation aerodynamic model estimation

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Investigation of E-H mode transition in magnetic-pole-enhanced inductively coupled neon-argon mixture plasma

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Plasma Science and Technology 2020年第6期22卷 110-119页

作者： Zahid Iqbal KHATTAK Abdul Waheed khan Faiq jan muhammad SHAFIQ Department of Physics Quaid-i-Azam University45320 IslamabadPakistan Department of Physics Gomal University29050 D.I.KhanPakistan Department of Physics Govt.Post Graduate College Nowshera24100 NowsheraPakistan 不详

In this paper,E-H mode transition in magnetic-pole-enhanced inductively coupled neon-argon mixture plasma is investigated in terms of fundamental plasma parameters as a function of argon fraction(0%-100%),operating pressure(1 Pa,5 Pa,10 Pa and 50 Pa),and radio frequency(RF)power(5-100 W).An RF compensated Langmuir probe and optical emission spectroscopy are used for the diagnostics of the plasma under *** to the lower ionization potential and higher collision cross-section of argon,when its fraction in the discharge is increased,the mode transition occurs at lower RF power;*** 0%argon and1 Pa pressure,the threshold power of the E-H mode transition is 65 W,which reduces to 20 W when the argon fraction is *** electron density increases with the argon fraction at afixed pressure,whereas the temperature decreases with the argon *** relaxation length of the low-energy electrons increases,and decreases for high-energy electrons with argon fraction,due to the Ramseur ***,the relaxation length of both groups of electrons decreases with pressure due to reduction in the mean free *** electron energy probability function(EEPF)profiles are non-Maxwellian in E-mode,attributable to the nonlocal electron kinetics in this mode;however,they evolve to Maxwellian distribution when the discharge transforms to H-mode due to lower electron temperature and higher electron density in *** tail of the measured EEPFs is found to deplete in both E-and H-modes when the argon fraction in the discharge is increased,because argon has a much lower excitation potential(11.5 eV)than neon(16.6 eV).

关键词： Ne-Ar MaPE-ICP Langmuir probe OES electron temperature electron density mode transition

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Reforming of Methane by CO2 over Bimetallic Ni-Mn/γ-Al2O3 Catalyst

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Chinese Journal of Chemical Physics 2014年第2期27卷 214-220,I0004页

作者： Anis Hamza Fakeeha muhammad Awais Naeem wasim Ullah khan Ahmed Elhag Abasaeed Ahmed Sadeq Al-Fatesh 沙特国王大学工程学院化学工程系利雅得11421

γ-Al2O3 supported Ni-Mn bimetallic catalysts for CO2 reforming of methane were prepared by impregnation method. The reforming reactions were conducted at 500-700℃ and atmospheric pressure using CO2/CH4/N2 with feed ratio of 17/17/2, at total flow rate of 36 mL/min. The catalytic performance was assessed through CH4 and CO2 conversions, synthesis gas ratio （H2/CO） and long term stability. Catalytic activity and stability tests revealed that addition of Mn improved catalytic performance and led to higher stability of bimetallic catalysts which presented better coke suppression than monometallic catalyst. In this work, the optimum loading of Mn which exhibited the most stable performance and least coke deposition was 0.5wt%. The fresh and spent catalysts were characterized by various techniques such as Brunauer-Emmett-Teller, the temperature programmed desorption CO2- TPD, thermogravimetric analysis, X-ray diffraction, scanning electron microscope, EDX, and infrared spectroscopy.

关键词： CH4 CO2 Bimetallic Dry reforming Ni/γ-Al2O3 Mn and H2/CO

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Spectrum of venous thromboembolism in adult patients with ulcerative colitis in Pakistan:A single center retrospective study

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World Journal of Clinical Cases 2025年第6期13卷 9-13页

作者： Masood muhammad Karim Hafsa Shaikh Faisal wasim Ismail Department of Medicine The Aga Khan University HospitalKarachi 74800Pakistan Department of General Surgery The Aga Khan University HospitalKarachi 74800Pakistan

BACKGROUND Patients with inflammatory bowel disease are at a 2-8-fold higher risk of deve-loping venous thromboembolism(VTE)as compared to the general *** the exact pathogenesis is unclear,the literature suggests that increased risk of thromboembolic events in such patients occurs as a result of increased coagulation factors,inflammatory cytokines,and reduction in anticoagulants leading to a prothrombotic *** To assess the prevalence,risk factors,management,and outcome of ulcerative colitis(UC)patients who develop *** This was a retrospective chart review done in The Gastroenterology Department of The Aga khan University *** was collected from medical records for all patients admitted with a diagnosis of UC from january 2012 to December *** Seventy-four patients fulfilled the inclusion *** mean±SD of age at presentation of all UC patients was 45 years±10 years whereas for those who developed VTE,it was 47.6 years±14.7 *** and diabetes were the most common co-morbid seen among UC patients with a frequency of 17(22.9%)and 12(16.2%),respectively.A total of 5(6.7%)patients developed *** venous thrombosis was the most common thromboembolic phenomenon seen in 3(60%)*** the patients with UC and concomitant VTE were discharged home(5;100%).CONCLUSION The prevalence of VTE with UC in Pakistani patients corresponds with the international ***,multi-centric studies are required to further explore these results.

关键词： Deep venous thrombosis Inflammatory bowel disease Low-middle-income country Anticoagulation Protein C deficiency

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Flower Pollination Heuristics for Nonlinear Active Noise Control Systems

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Computers, Materials & Continua 2021年第4期67卷 815-834页

作者： wasim Ullah khan Yigang He muhammad Asif Zahoor Raja Naveed Ishtiaq Chaudhary Zeshan Aslam khan Syed Muslim Shah School of Electrical Engineering and Automation Wuhan UniversityWuhan430072China Future Technology Research Center National Yunlin University of Science and TechnologyYunlin64002Taiwan Department of Electrical Engineering International Islamic UniversityIslamabadPakistan Department of Electrical Engineering Capital University of Science and TechnologyIslamabadPakistan

In this paper,a novel design of the flower pollination algorithm is presented for model identification problems in nonlinear active noise control *** recently introduced flower pollination based heuristics is implemented to minimize the mean squared error based merit/cost function representing the scenarios of active noise control system with linear/nonlinear and primary/secondary paths based on the sinusoidal signal,random and complex random signals as noise *** flower pollination heuristics based active noise controllers are formulated through exploitation of nonlinear filtering with Volterra *** comparative study on statistical observations in terms of accuracy,convergence and complexity measures demonstrates that the proposed meta-heuristic of flower pollination algorithm is reliable,accurate,stable as well as robust for active noise control *** accuracy of the proposed nature inspired computing of flower pollination is in good agreement with the state of the art counterpart solvers based on variants of genetic algorithms,particle swarm optimization,backtracking search optimization algorithm,fireworks optimization algorithm along with their memetic combination with local search ***,the central tendency and variation based statistical indices further validate the consistency and reliability of the proposed scheme mimic the mathematical model for the process of flower pollination systems.

关键词： Active noise control computational heuristics volterra filtering flower pollination algorithm

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Evaluation of microstructure and mechanical properties of squeeze overcast Al7075-Cu composite joints

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China Foundry 2023年第1期20卷 29-39页

作者： muhammad Waqas Hanif Ahmad wasim muhammad Sajid Salman Hussain muhammad Jawad Mirza Jahanzaib Department of Industrial Engineering University of Engineering and Technology TaxilaPunjabPakistan

Al7075-Cu composite joints were prepared by the squeeze overcast *** effects of melt temperature,die temperature,and squeeze pressure on hardness and ultimate tensile strength(UTS)of squeeze overcast Al7075-Cu composite joints were *** experimental results depict that squeeze pressure is the most significant process parameter affecting the hardness and *** optimal values of UTS(48 MPa)and hardness(76 HRB)are achieved at a melt temperature of 800℃,a die temperature of 250℃,and a squeeze pressure of 90 *** electron microscopy(SEM)shows that fractured surfaces show flatfaced morphology at the optimal experimental ***-dispersive spectroscopy(EDS)analysis depicts that the atomic weight percentage of Zn decreases with an increase in melt temperature and squeeze *** optimal mechanical properties of the Al7075-Cu overcast joint were achieved at the Al2Cu eutectic phase due to the large number of copper atoms that dispersed into the aluminum melt during the solidification process and the formation of strong intermetallic *** relational analysis integrated with the Taguchi method was used to develop an optimal set of control variables for multi-response parametric *** tests were performed to validate the effectiveness of the employed *** manufacturing of squeeze overcast Al7075-Cu composite joints at optimal process parameters delivers a great indication to acknowledge a new method for foundry practitioners to manufacture materials with superior mechanical properties.

关键词： squeeze overcast joints Al7075-Cu composite joints mechanical properties gray relational analysis Taguchi method

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Primary esophageal tuberculosis mimicking esophageal carcinoma on computed tomography: A case report

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World Journal of Gastrointestinal Surgery 2019年第9期11卷 373-380页

作者： muhammad Salman khan muhammad Hassaan Arif Maan Amir Humza Sohail wasim Ahmed Memon Department of Radiology Aga Khan UniversityKarachi 74800Pakistan Medical College Aga Khan UniversityKarachi 74800Pakistan Department of Surgery New York University Winthrop HospitalNew YorkNY 11501United States

BACKGROUND Tuberculosis(TB)has a rare extrapulmonary manifestation known as esophageal tuberculosis,accounting for 0.2%of total TB *** TB typically presents with dysphagia,with retrosternal pain or odynophagia,but generalized symptoms such as low-grade fever,decreased appetite,and weight loss are also *** carcinoma and Crohn’s disease of the esophagus are important differential diagnoses with similar *** SUMMARY We present a case of a 25-year-old male,who presented with esophageal TB mimicking an esophageal *** work-up,Mantoux test,and chest X-ray were ***-swallow examination showed moderate dilatation of distal esophagus with a nodular and irregular *** tomography showed significant thickening of thoracic and distal esophagus with infiltration into the lesser omentum and large,centrally necrotic lymph nodes on gastro-hepatic ligament suggestive of a possible *** was performed and a biopsy of mural thickening was performed and sent for histopathological *** histopathology report and TB-polymerase chain reaction confirmed the diagnosis of esophageal *** patient was started on antituberculous therapy(ATT),and complete resolution of symptoms and disease was achieved in 6 *** Esophageal TB is an extremely rare,yet important differential diagnosis in a patient presenting with *** TB can mimic esophageal carcinoma on computed tomography *** patient responded well to a complete course of ATT.

关键词： Case report Esophageal tuberculosis Esophageal carcinoma Computed tomography

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Sunflower-Like SrCo_(2)S_(4)@f-MWCNTs Hybrid Wrapped by Engineering N-Reduced Graphene Oxide for High Performance Dye-Sensitized Solar Cells

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Journal of Renewable Materials 2020年第4期8卷 431-446页

作者： Weiming Zhang muhammad wasim khan Xueqin Zuo Qun Yang Huaibao Tang Shaowei Jin Guang Li School of Physics and Materials Science Anhui UniversityHefei230601China Anhui Key Laboratory of Information Materials and Devices Hefei230601China Institute of Physical Science and Information Technology Anhui UniversityHefei230601China

A novel sunflower-like nanocomposite of SrCo_(2)S_(4)nanoflakes and functionalized multiwall carbon nanotubes(f-MWCNTs)entanglement enveloped in nitrogen-reduced graphene oxide(N-RGO)is prepared by a cheap *** unique entanglement structure of the material exhibits higher specific surface area,better electrical conductivity and other *** helps to reduce the transfer resistance in the photoelectric process of the battery and improve the electrochemical activity,thus increasing the photoelectric conversion efficiency of the *** new ternary cobalt-based sulfide material can replace platinum as the counter electrode(CE)material loaded on dye-sensitized solar cells(DSSCs).DSSCs with SrCo_(2)S_(4)@f-MWCNTs@N-RGO(SCS@f-M@N-R)as CE material show excellent photoelectric conversion efficiency(PCE,8.06%),even surpassing than that of Pt CE material(7.51%).The low cost,excellent electrocatalytic performance and simple preparation method of SCS@f-M@N-R nanomaterial provide feasibility for replacing platinum material as the CE material of DSSCs,which is of great significance and persuasion.

关键词： Dye-sensitized solar cells sunflower-like multiwall carbon nanotubes SrCo_(2)S_(4) counter electrode

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Analysis of the effect of passive measures on the energy consumption and zero-energy prospects of residential buildings in Pakistan

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Building Simulation 2021年第4期14卷 1325-1342页

作者： muhammad wasim Anwar Zaib Ali Abdullah Javed Emad Ud Din muhammad Sajid School of Mechanical and Manufacturing Engineering National University of Sciences and TechnologyIslamabadPakistan

Climate change can adversely impact the thermal comfort and energy efficiency of the buildings stock. The South Asian countries are particularly vulnerable to the adverse impacts of climate change specially in the form of rising temperatures and increasing frequency of heat waves. The passive building design measures can be useful in mitigating and adapting to the climate change by increasing energy efficiency and reducing greenhouse gas (GHG) emissions. In this study various passive climate change adaptation measures (PCAMs) have been used individually and in form of combinations in order to analyze their impact on the energy efficacy of residential buildings in Pakistan. It has been found that the natural ventilation and front green wall are the most efficient options for reducing the overall energy consumption. By implementation of these PCAMs, cooling demand can be decreased by 27.75% while heating demand can be reduced by 35%. Secondly, the prospect of net zero-energy building and reduced CO2 emissions are also studied. It has been shown that building can achieve net-zero energy on an annual basis at every orientation and it can attain the status of nearly zero-energy building on a monthly basis. Moreover, emitted CO2 can be reduced by 31% by using the renewable energy.

关键词： building energy simulations net zero-energy passive climate adaptation measures climate change energy consumption Pakistan

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