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Ammonium metavanadate:A novel catalyst for synthesis of 2-substituted benzimidazole derivatives

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Chinese Chemical Letters 2009年第3期20卷 292-295页

作者： Ganesh R.Jadhav mohammad u.shaikh Rajesh P.Kale Charansingh H.Gill Department of Chemistry Dr.Babasaheb Ambedkar Marathwada UniversityAurangabadMaharashtra 431 004India Division of Medicinal Chemistry Wockhardt Research CentreD-4Chikalthana M.I.D.C.AreaAurangabadMaharashtra 431 210India

Ammonium metavanadate （10 mol%） was found to be a useful catalyst for the synthesis of various 2-substituted aryl benzimidazoles. It was used as an oxidizing agent for the condensation of o-phenylenediamine with different substituted aryl aldehydes at room temperature in ethanol. The method was proved to be simple, convenient and the product was isolated with good yields （79-91%）.

关键词： Ammonium metavanadate Oxidation Aryl aldehyde Benzimidazole

Potassium dihydrogen phosphate catalyzed one-pot synthesis of 2,4,5-triaryl-1H-imidazoles

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Chinese Chemical Letters 2010年第4期21卷 429-432页

作者： Ratnadeep S.Joshi Priyanka G.Mandhane mohammad u.shaikh Rajesh P.Kale Charansingh H.Gill Department of Chemistry Dr.Babasaheb Ambedkar Marathwada UniversityAurangabadMaharashtra 431 004India

A simple and efficient method has been developed;benzil/benzoin undergoes smooth condensation with various substituted aldehyde and ammonium acetate in the presence of potassium dihydrogen phosphate（KH;PO;） under mild reaction conditions to afford the corresponding trisubstituted imidazole in excellent *** method for synthesis of product,the reaction mixture was reflux in ethanol for 40-90 *** present method is simple,efficient,and cost-effective.

关键词： Potassium dihydrogen phosphate(KH_2PO_4) 2 4 5-Triaryl-1H-imidazole Benzil Benzoin Aldehyde Ammonium acetate

Robust design of sliding mode control for airship trajectory tracking with uncertainty and disturbance estimation

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Journal of Systems Engineering and Electronics 2024年第1期35卷 242-258页

作者： WASIM Muhammad ALI Ahsan CHOuDHRY mohammad Ahmad shaikh Inam ul Hasan SALEEM Faisal Department of Aeronautics and Astronautics Engineering Institute of Space TechnologyIslamabad 44000Pakistan Department of Electrical Engineering University of Engineering and TechnologyTaxila 47080Pakistan Department of Measurements and Control Systems Silesian University of TechnologyGliwice 44-101Poland The Joint Doctoral School Silesian University of TechnologyGliwice 44-100Poland

The robotic airship can provide a promising aerostatic platform for many potential *** applications require a precise autonomous trajectory tracking control for *** has a nonlinear and uncertain *** is prone to wind disturbances that offer a challenge for a trajectory tracking control *** paper addresses the airship trajectory tracking problem having time varying reference path.A lumped parameter estimation approach under model uncertainties and wind disturbances is opted against distributed *** uses extended Kalman filter(EKF)for uncertainty and disturbance *** estimated parameters are used by sliding mode controller(SMC)for ultimate control of airship trajectory *** comprehensive algorithm,EKF based SMC(ESMC),is used as a robust solution to track airship *** proposed estimator provides the estimates of wind disturbances as well as model uncertainty due to the mass matrix variations and aerodynamic model *** stability and convergence of the proposed method are investigated using the Lyapunov stability *** simulation results show that the proposed method efficiently tracks the desired *** method solves the stability,convergence,and chattering problem of SMC under model uncertainties and wind disturbances.

关键词： airship chattering extended Kalman filter(EKF) model uncertainties estimation sliding mode controller(SMC)

Social Media-Based Surveillance Systems for Health Informatics using Machine and Deep Learning Techniques:A Comprehensive Review and Open Challenges

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Computer Modeling in Engineering & Sciences 2024年第5期139卷 1167-1202页

作者： Samina Amin Muhammad Ali Zeb Hani Alshahrani Mohammed Hamdi mohammad Alsulami Asadullah shaikh Institute of Computing Kohat University of Science and TechnologyKohat26000Pakistan Department of Computer Science College of Computer Science and Information SystemsNajran UniversityNajran61441Saudi Arabia Department of Information System College of Computer Science and Information SystemsNajran UniversityNajran61441Saudi Arabia

Social media(SM)based surveillance systems,combined with machine learning(ML)and deep learning(DL)techniques,have shown potential for early detection of epidemic *** review discusses the current state of SM-based surveillance methods for early epidemic outbreaks and the role of ML and DL in enhancing their ***,every year,a large amount of data related to epidemic outbreaks,particularly Twitter data is generated by *** paper outlines the theme of SM analysis for tracking health-related issues and detecting epidemic outbreaks in SM,along with the ML and DL techniques that have been configured for the detection of epidemic *** has emerged as a promising ML technique that adaptsmultiple layers of representations or features of the data and yields state-of-the-art extrapolation *** recent years,along with the success of ML and DL in many other application domains,both ML and DL are also popularly used in SM *** paper aims to provide an overview of epidemic outbreaks in SM and then outlines a comprehensive analysis of ML and DL approaches and their existing applications in SM ***,this review serves the purpose of offering suggestions,ideas,and proposals,along with highlighting the ongoing challenges in the field of early outbreak detection that still need to be addressed.

关键词： Social media epidemic machine learning deep learning health informatics pandemic

Triad-displaced uLAs configuration for non-circular sources with larger continuous virtual aperture and enhanced degrees of freedom

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Journal of Systems Engineering and Electronics 2024年第1期35卷 81-93页

作者： shaikh Abdul Hayee DANG Xiaoyu HuANG Daqing College of Electronic and Information Engineering Nanjing University of Aeronautics and AstronauticsNanjing 211106China

Non-uniform linear array(NuLA)configurations are well renowned due to their structural ability for providing increased degrees of freedom(DOF)and wider array aperture than uniform linear arrays(uLAs).These characteristics play a significant role in improving the direction-of-arrival(DOA)estimation ***,most of the existing NuLA geometries are primarily applicable to circular sources(CSs),while they limitedly improve the DOF and continuous virtual aperture for noncircular sources(NCSs).Toward this purpose,we present a triaddisplaced uLAs(Tdis-uLAs)configuration for *** TdisuLAs structure generally consists of three uLAs,which are appropriately *** proposed antenna array approach fully exploits the non-circular characteristics of the *** the same number of elements,the Tdis-uLAs design achieves more DOF and larger hole-free co-array aperture than its sparse array ***,the number of uniform DOF,optimal distribution of elements among the uLAs,and precise element positions are uniquely determined by the closed-form ***,the proposed array also produces a filled resulting *** simulations are conducted to show the performance advantages of the proposed Tdis-uLAs configuration over its counterpart designs.

关键词： direction-of-arrival(DOA)estimation sparse array non-circular source(NCS) sum co-array difference co-array degrees of freedom(DOF)

Microalgae cultivation in photobioreactors: sustainable solutions for a greener future

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Green Chemical Engineering 2024年第4期5卷 418-439页

作者： shaikh Abdur Razzak Khairul Bahar K.M.Oajedul Islam Abdul Khaleel Haniffa Mohammed Omar Faruque S.M.Zakir Hossain mohammad M.Hossain Chemical Engineering Department King Fahd University of Petroleum and Minerals Center for Refining and Advanced Chemicals King Fahd University of Petroleum & Minerals Department of Chemical Engineering University of Bahrain

Microalgae cultivation in photobioreactors（PBRs） has emerged as a promising and sustainable approach to address various environmental and energy challenges, offering a multitude of benefits across diverse *** developments in microalgae cultivation in photobioreactors have contributed substantially to the development and optimization of sustainable bioprocesses. This review presents a comprehensive analysis of recent innovations and breakthroughs in the field of microalgae cultivation, with a specific focus on their application in photobioreactors, aimed at paving the way for a greener future. This study in-depth examines the advantages of microalgae cultivation in photobioreactors, concentrating on its effectiveness in wastewater treatment, CO2bioremediation, and the production of biofuels and high-value products. The review evaluates the effects of light,solar irradiation, temperature, nitrogen and phosphorus concentrations in culture media, CO2concentrations, and pH on microalgae growth performance, including specific growth and biomass productivity. The study also examines open systems like unstirred ponds, raceway ponds, and circular ponds and closed systems like horizontal tubular, vertical bubble-column, airlift, flat panel, and plastic-bag photobioreactors, comparing their pros and cons. To optimize microalgae cultivation, key factors in photobioreactor design, including photosynthetic efficiencies, light/dark（L/D） cycles, CO2concentrations, mass transfer, hydrodynamics behavior, and p H, are extensively investigated. In addition, the review outlines recent developments in large-scale photobioreactors and highlights the challenges and opportunities associated with photobioreactor scale-up and design parameter optimization, including genetic engineering and economic feasibility. This article is a vital resource for researchers, engineers, and industry professionals seeking sustainable bioprocesses and the application of microalgae-based technol

关键词： Microalgae biomass CO 2 biofixation Wastewater treatment Biofuel Photobioreactors

Fine Sand and Clay Sediment Acoustic Properties of the Novel Sediment Sample from the Arabian Sea:Experimental Investigations and Biot−Stoll Model Validation

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China Ocean Engineering 2024年第1期38卷 169-180页

作者： Shahabuddin shaikh HuANG Yi-wang ZHANG Ze-chuan Habib Hussain ZuBERI National Key Laboratory of underwater Acoustic Technology and College of underwater Acoustic Engineering Harbin Engineering UniversityHarbin 150001China

The present study explores the physical and acoustic characteristics of fine sand and clay in novel seabed marine sediments from of Pakistan coastline of the Arabian *** measured physical parameters included mean grain size,mass density,bulk density,salinity,porosity,permeability,pore size and mineralogical *** properties,including sound speed and attenuation,in the high frequency range of 90-170 kHz were analyzed.A controlled laboratory setup with the acoustic transmission method and Fourier transform techniques was utilized to examine the sound propagation and absorption of novel seabed *** standard deviation of mean sound speed in fresh water was 0.75 m/s,and attenuation was observed in the range of 0.43 to 0.61 dB/*** mean sound velocity in sand and clay varied from 1706 to 1709 m/s and 1602 to 1608 m/s,*** average attenuation was observed at 80 to 93 dB/m in sandy sediments and from 31.8 to 38.6 dB/m in clayey *** velocity variation within sandy sediment is low,consistent with expected results,and smaller than the predicted ***,clay sediment exhibited a positive linear correlation and low sound speed *** increased linearly with frequency for both ***,the laboratory results were validated by using the Biot−Stoll *** dispersion of sound speed in sandy and clayey sediments was consistent with the predictions of the Biot−Stoll *** attenuation aligned more with Biot−Stoll model predictions due to improved permeability,tortuosity and pore size parameter fitting.

关键词： physical and acoustic characteristics marine sediments sound speed attenuation Biot−Stoll model

Geomorphic signatures and active tectonics in western Saurashtra,Gujarat,India

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Geodesy and Geodynamics 2024年第1期15卷 82-99页

作者： Bikramaditya Mondal Mery Biswas Soumyajit Mukherjee Mohamedharoon A.shaikh Department of Earth Sciences Indian Institute of Technology BombayMumbai 400076MaharashtraIndia Department of Geography Presidency UniversityKolkata 700073West BengalIndia

Active tectonics in an area includes ongoing or recent geologic *** paper investigates the tectonic influence on the subsidence,uplift and tilt of western Saurashtra through morphotectonic analysis of ten watersheds along with characteristics of relief and drainage *** 7-9 to the north(N)are tectonically active,which can be linked with the North Kathiawar Fault System(NKFS)and followed by watersheds 6,10,1,4 and ***-length gradient index and sinuosity index indicate the effect of tectonic events along the master streams in watersheds *** R^(2)values of the linear curve fit for watershed 7 indicate its master stream is much more tectonically active than the *** R^(2)curve fitting model and earthquake magnitude/depth analysis confirm the region to be *** reactivation of the NKFS most likely led to the vertical movement of western Saurashtra.

关键词： Active tectonics Geomorphology Western Saurashtra Archeology North kathiawar fault system

understanding the catalytic performance and deactivation behaviour of second-promoter doped Pt/WO_(χ)/γ-Al_(2)O_(3) catalysts in the glycerol hydrogenolysis for selective and cleaner production of 1,3-propanediol

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Journal of Energy Chemistry 2024年第7期94卷 486-507页

作者： Rafik Rajjak shaikh Sittichai Damruang Rais Ahmad Khan Supareak Praserthdam Piyasan Praserthdam Center of Excellence on Catalysis and Catalytic Reaction Engineering(CECC) Department of Chemical EngineeringFaculty of EngineeringChulalongkorn UniversityBangkok 10330Thailand Department of Chemistry College of ScienceKing Saud UniversityP.O.Box 2455Riyadh 11451Saudi Arabia High-Performance Computing unit(CECC-HCu) Centre of Excellence on Catalysis and Catalytic Reaction Engineering(CECC)Department of Chemical EngineeringFaculty of EngineeringChulalongkorn UniversityBangkok 10330Thailand

The selective aqueous-phase glycerol hydrogenolysis is a promising reaction to produce commercially useful 1,3-propanediol(1,3-PDO).The Pt-WOx bifunctional catalyst can catalyse the glycerol hydrogenol-ysis but the catalyst deactivation via sintering,metal leaching,and coking can predominantly occur in the aqueous phase *** this work,the effect of reaction temperature,pressure and second promoter(Cu,Fe,Rh,Mn,Re,Ru,Ir,Sn,B,and P)on catalytic performance and deactivation behaviour of Pt/WOx/-Al2O3 was *** doped with Rh,Mn,Re,Ru,Ir,B,and P,the second promoter boosts catalytic activity by promoting great dispersion of Pt on support and increasing Pt surface *** increased Bronsted acid sites lead to selective synthesis of 1,3-PDO than 1,2-propanediol(1,2-PDO).The characterization studies of fresh and spent catalysts reveal that the main cause of catalyst deactivation is the Pt sintering,as interpreted based on XRD,CO chemisorption,and TEM *** Pt sintering is affected depending on the second promoter that can either or reduce the interaction between Pt,WO_(χ)/γ and Al_(2)O_(3).As an electron acceptor of Pt in Pt/WO_(χ)/γ-Al_(2)O_(3),Re and Mn as second promoters resulted in increased Pt^(2+) on the catalytic surface,which strengthens the contact between Pt andγ-Al_(2)O_(3) and WO_(χ),resulting in a decrease in Pt *** metal leaching and coking are not affected by the presence of second *** catalyst modified with a second promoter possesses improved catalytic activity and 1,3-PDO production,however the stability continues to remain a *** present work unrav-elled the determining parameters of catalytic activity and deactivation,thus providing a promising pro-tocol toward effective catalysts for glycerol hydrogenolysis.

关键词： Glycerol hydrogenolysis 1,3-propanediol Metal-support interaction Second promoter Liquid phase Catalyst deactivation