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Non Planar Electrostatic Solitary Wave Structures in Negative Ion Degenerate Plasma

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Chinese Physics Letters 2011年第4期28卷 148-151页

作者： S.Hussain N.Akhtar Saeed-ur-rehman Theoretical Plasma Physics Division PINSTECHNiloreIslamabad Department of Physics and Applied Mathematics PIEAS NiloreIslamabad

Theoretical and numerical studies are performed for quantum ion acoustic solitons in planar and non-planar geometries in an unmagnetized homogenous plasma consisting of warm positive and negative ions with nonthermal electrons.A deformed Korteweg de Vries(DKdV)equation is derived by using the reductive perturbation *** numerical solution to the DKdV equation indicates that the quantum parameter,temperatures of positive ions,temperture of negative ions and electron density blatantly influence the propagation speed and the structure of quantum ion acoustic *** geometrical effects on the structure of quantum ion acoustic wave are *** is shown that the amplitude and propagation speed in spherical geometry is larger as compared to cylinderical and planar geometries for different values of the above-mentioned parameters.

关键词： method quantum planar

Synthesis, Structural Investigations and Biological Screening of Diorganotin(IV) Complexes Derived from 5,5-Diethyl Sodium Barbital

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Chinese Journal of Structural Chemistry 2009年第4期28卷 419-426页

作者： Wajid rehman Amin Badshah Salimullah Khan Iftikhar Ahmad Department of Chemistry Hazara University Department of Chemistry Quaid-e-Azam University Department of Pharmacy Hazara University Department of Physics Louisiana State University

Some biologically important tin（Ⅳ） complexes derived from 5,5-diethyl sodium barbital have been synthesized and characterized through various analytical and spectroscopic techniques such as IR, ^1H-, ^13C-NMR and ^119mSn mossbauer. On the basis of these spectroscopic techniques, octahedral geometry has been assigned to all the novel compounds. These complexes, soluble in DMSO and DMF, were screened against a wide range of microorganisms. The results proved that the diphenyltin（Ⅳ） and dibutyltin（Ⅳ） complexes exhibit excellent activity against all types of microorganisms, while the rest of the compounds show significant activity that can be used during the biological study.

关键词： 5,5-diethyl sodium barbital spectra antibacterial anti-inflammatory organotin

Dynamics and Small Signal Stability Analysis of PMSG-based Wind Farm with an MMC-HVDC System

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CSEE Journal of Power and Energy Systems 2020年第1期6卷 226-235页

作者： Yifan Wang Chengyong Zhao Chunyi Guo Atiq Ur rehman The State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power UniversityBeijing 102206China

The permanent magnet synchronous generator (PMSG)-based wind farm with a modular multilevel converter (MMC) based HVDC system exhibits various oscillations and can experience dynamic instability due to the interactions between different controllers of the wind farm and MMC stations, which have not been properly examined in the existing literatures. This paper presents a dynamic modeling approach for small signal stability analysis of PMSG-based wind farms with a MMC- HVDC system. The small signal model of the study system is validated by the comprehensive electromagnetic transient (EMT) simulations in PSCAD/EMTDC. Then the eigenvalue approach and participation factors analysis are utilized to comprehensively evaluate the impact of different controllers, system’s parameters and the circulating current suppressing controller (CCSC) on the small signal stability of the entire system. From eigenvalue analysis, it is revealed that as the output active power of the wind farm increases within the rated range, the overall system will exhibit a sub-synchronous oscillation (SSO) instability mode, an extremely weak damping mode, and a low frequency oscillation instability mode. From participation factors analysis, it is observed that the SSO mode and weak damping mode are primarily related to the internal dynamics of the MMC, which can be suppressed or improved by CCSC. It is determined that the low frequency oscillation mode is primarily caused by the interactions between the phase locked loop (PLL) control of the wind farm and the voltage and frequency (V-F) control of the MMC station. The analysis also depicts that the larger proportional gain value of the V-F control of the MMC station and smaller PLL bandwidth of the wind farm can enhance the small signal stability of the entire system.

关键词： HVDC modular multilevel converter(MMC) permanent magnet synchronous generator(PMSG) small signal stability sub-synchronous oscillation(SSO) wind farm

Designing and Evaluating a Collaborative Knowledge Management Framework for Leaf Disease Detection

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Computer Systems Science & Engineering 2022年第8期42卷 751-777页

作者： Komal Bashir Mariam rehman Afnan Bashir Faria Kanwal Department of Computer Science Lahore College for Women UniversityLahore54000Pakistan Department of Information Technology Government CollegeFaisalabad54000Pakistan Engage Research Lab School of Law and SocietyUniversity of the Sunshine CoastSippy DownsQLD 4556Australia

Knowledge Management(KM)has become a dynamic concept for inquiry in *** management of knowledge from multiple sources requires a systematic approach that can facilitate capturing all important aspects related to a particular discipline,several KM frameworks have been designed to serve this *** research aims to propose a Collaborative Knowledge Management(CKM)Framework that bridges gaps and overcomes weaknesses in existing *** paper also validates the framework by evaluating its effectiveness for the agriculture sector of Pakistan.A software LCWU aKMS was developed which serves as a practical implementation of the concepts behind the proposed CKMF *** aKMS served as an effective system for rice leaf disease detection and *** aimed to enhance CKM through knowledge sharing,lessons learned,feedback on problem resolutions,help from co-workers,collaboration,and helping *** were collected from 300 rice crop farmers by questionnaires based on *** Olfman model was used to estimate the effectiveness of *** tests were performed including frequency measures of variables,Cronbach’s alpha reliability,and Pearson’s *** research provided a KMS depicting KM and collaborative *** disease detection module was evaluated using the precision and recall method and found to be 94.16%*** system could replace the work of extension agents,making it a cost and time-effective initiative for farmer betterment.

关键词： Collaborative knowledge management framework jennex olfman km success model knowledge management rice disease detection

Nanocarbon-based electrode materials applied for supercapacitors

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Rare Metals 2022年第12期41卷 3957-3975页

作者： Yu-Xiang Yang Kang-Kang Ge Sajid ur rehman Hong Bi School of Chemistry and Chemical Engineering School of Materials Science and EngineeringAnhui UniversityHefei 230601China CIRIMAT UMR CNRS 5085UniversitéPaul Sabatier ToulouseⅢToulouse 31062France CAS Key Laboratory of High Magnetic Field and Ion Beam Physical Biology Hefei Institutes of Physical ScienceChinese Academy of SciencesHefei 230031China

As one of the promising energy storage and conversion systems,supercapacitors(SCs)are highly favored owing to their high power density and good service *** all the key components of supercapacitor devices,the design and investigation of electrode materials play an essential role in determining the whole electrochemical charge storage ***,nanocarbon-based materials(e.g.,graphene,carbon dots,graphene quantum dots,etc.)have been widely used as SC electrode materials because of their good physical structure and chemical properties,providing a new route to further improve the energy density and life span of ***,we review the latest progress of nanocarbon-based materials(including nanocarbon and nanocarbon-based composite materials)as electrode materials in SCs *** recent progress of carbon dots,graphene,carbon nanotubes,and other nanocarbon materials electrodes is summarized,while the capacitance and energy density of the above nanocarbon electrodes still need to be ***,the preparation and performance of nanocarbonbased composite electrodes comprising transition metal oxides,conductive polymer,and metal-organic framework derived porous carbon are ***,we outline major challenges and propose some ideas on building better nanocarbon-based SC electrodes.

关键词： Supercapacitor(SC) Nanocarbon Electrode materials Carbon dots Nanocarbon-based composite

Authentication of Vehicles and Road Side Units in Intelligent Transportation System

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Computers, Materials & Continua 2020年第7期64卷 359-371页

作者： Muhammad Waqas Shanshan Tu Sadaqat Ur rehman Zahid Halim Sajid Anwar Ghulam Abbas Ziaul Haq Abbas Obaid Ur rehman Beijing Key Laboratory of Trusted Computing Faculty of Information TechnologyBeijing University of TechnologyBeijing100124China Faculty of Computer Science&Engineering Ghulam Ishaq Khan Institute of Engineering Sciences&TechnologyTopi23460Pakistan Beijing Electro-Meahnical Engineering Institute Beijing100074China Faculty of Electrical Engineering Ghulam Ishaq Khan Institute of Engineering Sciences&TechnologyTopi23460Pakistan Department of Electrical Engineering Sarhad University of Science and Information TechnologyPeshawar25000Pakistan

Security threats to smart and autonomous vehicles cause potential consequences such as traffic accidents,economically damaging traffic jams,hijacking,motivating to wrong routes,and financial losses for businesses and *** and autonomous vehicles are connected wirelessly,which are more attracted for attackers due to the open nature of wireless *** of the problems is the rogue attack,in which the attacker pretends to be a legitimate user or access point by utilizing fake *** figure out the problem of a rogue attack,we propose a reinforcement learning algorithm to identify rogue nodes by exploiting the channel state information of the communication *** consider the communication link between vehicle-to-vehicle,and *** evaluate the performance of our proposed technique by measuring the rogue attack probability,false alarm rate(FAR),mis-detection rate(MDR),and utility function of a receiver based on the test threshold values of reinforcement learning *** results show that the FAR and MDR are decreased significantly by selecting an appropriate threshold value in order to improve the receiver’s utility.

关键词： Intelligent transportation system authentication rogue attack

The Stability of Some Viable Stars and Electromagnetic Field

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Chinese Physics Letters 2016年第7期33卷 25-27页

作者： M.Azam S.A.Mardan M.A.rehman Division of Science and Technology University of EducationTownship Campus Department of Mathematics University of the Management and Technology

We examine the impact of electromagnetic field on the stability of compact stars corresponding to embedded class one metric using the concept of cracking. For this purpose, we develop the generalized hydrostatic equi- librium equation for charged perfect fluid distribution of compact stars and perturb it by means of local density perturbation scheme to check the stability of inner matter configuration. We investigate the cracking of Her X-I, PSR 1937＋21, PSR J 1614-2230, PSR J 0348＋0432 and B.X J 1856-37. We conclude that PSR J 0348＋0432 and RX J 1856-37 exhibit cracking when charge is introduced on these astrophysical objects.

关键词： of in et it on PSR The Stability of Some Viable Stars and Electromagnetic Field for

Salt Stress Threshold in Millets:Perspective on Cultivation on Marginal Lands for Biomass

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Phyton-International Journal of Experimental Botany 2021年第1期90卷 51-64页

作者： Naveed Ul Mushtaq Seerat Saleem Aadil Rasool Wasifa Hafiz Shah Khalid rehman Hakeem Reiaz Ul rehman Department of Bioresources School of Biological SciencesUniversity of KashmirSrinagar190006India Department of Biological Sciences Faculty of ScienceKing Abdulaziz UniversityJeddah21589Saudi Arabia

Millets hold an immense assurance for food safety and nourishment amid ever-rising agricultural expenses and climate *** are healthful,have supplementary wellbeing profit and need remarkably fewer effort overheads for crop *** characters draw attention to millets as a plant of preference for the humankind in the course of emergent alarm about environmental *** have the prospect to provide biomass and thus bioenergy,reduced carbon emission,carbon footprint and sustainable modern *** the rate of expansion in budding countries is increasing day by day,the scarcity of energy is a big panic and there is a mounting turn in the direction and rehearsal of waste and biomass as an energy ***,at least 20%of total irrigated land has been injured by salt and 1.5 million hectares is taken away of cultivation every ***,in future,we will have a requirement of efficient crops and utilisation of marginal lands for *** is an answer to the efficient *** are subjected to various environmental pressures(high/low temperature,heavy metal,salinity,pesticides,etc.)as well as biotic stresses(virus,bacteria,fungi,etc.)and millets are not an exception to *** are categorised as glycophytes and can tolerate average salt threshold of about 6(ECe)(dS/m)with some variation from specie to *** in the salt concentrations can lead to retarded growth and development,thus need for mitigants arise to reduce such *** mitigants to overcome the stress levels include proline,polyamine and betaines,Na2SeO3,H2S,KNO3,Mg(NO3)2,etc.

关键词： Sustainable development proline salt tolerance biomass food security

Bioassay studies of cobalt (Ⅱ) complexes of modified diamine

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Frontiers of Chemistry in China 2011年第2期6卷 98-104页

作者： Saeed-UR-rehman Muhammad IKRAM Sadia rehman Shah NAWAZ Institute of Chemical Sciences University of PeshawarPeshawar 25120Pakistan

Coordination compounds of modified diamine,the basic unit of which are ethylenediamine,with that of Co(Ⅱ)are *** modified diamines are ethylenediaceticacid(EDDA)and N,N,N,N-tetaraethylene-1,2-diamine(TEEDA).These diamines are characterized through ^(1)H-NMR,^(13)C-NMR,elemental analysis and IR ***(Ⅱ)complexes of these two ligands were prepared and characterized by physical measurements including elemental analysis,IR,UVVisible,magnetic susceptibilities and conductance *** activities are also carried out in order to investigate the biological activity upon *** were screened against four pathogenic bacteria like Escherichia coli,Pseudomonas aeroginosa,Klesbella pneumonia and Staphylococcus *** results showed significant enhancement in activities.

关键词： EDDA TEEDA cobalt complexes antibacterial studies