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MHD Flow of an Oldroyd-B Fluid through a Porous Space Induced by Sawtooth Pulses

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Chinese Physics Letters 2011年第8期28卷 161-164页

作者： Masood khan Zeeshan Department of Mathematics Quaid-i-Azam UniversityIslamabad 44000Pakistan

We investigate the unsteady magnetohydrodynamic(MHD)flow of an Oldroyd-B fluid through a porous space induced by sawtooth *** fluid is assumed to be electrically conducting in the presence of a transverse uniform magnetic *** porous space is taken into account using modified Darcy's law for the Oldroyd-B *** solutions of the governing problem are obtained by using the Laplace transform *** effects of the magnetic parameter,the permeability of the porous space and the elasticity parameter of the fluid are studied on the flow characteristics.

关键词： method field porous

Impact of selection of DC base values and DC link control strategies on sequential AC-DC power-flow convergence

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Frontiers in Energy 2015年第4期9卷 399-412页

作者： Shagufla khan Suman BHOWMICK Department of Electrical Engineering Delhi Technological University Delhi 110042 India

This paper demonstrates the convergence of the integrated AC-DC power-flow algorithm as affected by the selection of different base values for the DC quantities and adoption of different control strategies for the DC link. For power-flow modeling of integrated AC-DC systems, the base values of the various DC quantities can be defined in several ways, giving rise to different sets of per-unit system equations. It is observed that different per-unit system models affect the convergence of the power-flow algorithm differently. In a similar manner, the control strategy adopted for the DC link also affects the power- flow convergence. The sequential method is used to solve the DC variables in the Newton Raphson （NR） power flow model, where AC and DC systems are solved separately and are coupled by injecting an equivalent amount of real and reactive power at the terminal AC buses. Now, for a majority of the possible control strategies, the equivalent real and reactive power injections at the concerned buses can be computed a-priori and are independent of the NR iterative loop. However, for a few of the control strategies, the equivalent reactive power injections cannot be computed a-priori and need to be computed in every NR iteration. This affects the performance of the iterative process. Two different per-unit system models and six typical control strategies are taken into consideration. This is validated by numerous case studies conducted on the IEEE 118-bus and 300-bus test systems.

关键词： AC-DC power-flow Newton-Raphsonmethod high voltage direct current (HVDC) controlstrategy

Smart Object Detection and Home Appliances Control System in Smart Cities

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Computers, Materials & Continua 2021年第4期67卷 895-915页

作者： Sulaiman khan Shah Nazir Habib Ullah khan Department of Computer Science University of SwabiKPPakistan Department of Accounting and Information Systems College of Business and EconomicsQatar UniversityDohaQatar

During the last decade the emergence of Internet of Things(IoT)based applications inspired the world by providing state of the art solutions to many common *** traffic management systems to urban cities planning and development,IoT based home monitoring systems,and many other smart *** of these facilities,most of these IoT based solutions are data driven and results in small accuracy values for smaller *** order to address this problem,this paper presents deep learning based hybrid approach for the development of an IoT-based intelligent home security and appliance control system in the smart *** hybrid model consists of;convolution neural network and binary long short term model for the object detection to ensure safety of the homes while IoT based hardware components like;Raspberry Pi,Amazon Web services cloud,and GSM modems for remotely accessing and controlling of the home *** android application is developed and deployed on Amazon Web Services(AWS)cloud for the remote monitoring of home appliances.A GSM device and Message queuing telemetry transport(MQTT)are integrated for communicating with the connected IoT devices to ensure the online and offline *** object detection purposes a camera is connected to Raspberry Pi using the proposed hybrid neural network *** applicability of the proposed model is tested by calculating results for the object at varying distance from the camera and for different intensity levels of the *** many applications the proposed model promises for providing optimum results for the small amount of data and results in high recognition rates of 95.34%compared to the conventional recognition model(k nearest neighbours)recognition rate of 76%.

关键词： Hybrid deep learning model IoT smart cities home appliances control system and Amazon web services

Multiuser Detection for MIMO-OFDM system in Underwater Communication Using a Hybrid Bionic Binary Spotted Hyena Optimizer

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Journal of Bionic Engineering 2021年第2期18卷 462-472页

作者： Md Rizwan khan Bikramaditya Das Department of Electronics&Telecommunication Engineering VSS University of TechnologyBurla-768018OdishaIndia

Multi Access Interference (MAI) is the main source limiting the capacity and quality of the Multiple-Input Multiple-Output Orthogonal Frequency Division Multiplexing (MIMO-OFDM) system which fulfills the demand of high-speed transmission rate and high quality of service for future underwater acoustic (UWA) communication. Multi User Detection (MUD) is needed to overcome the performance degradation caused by MAI. In this research, both local and global optimal solutions are obtained in Bionic Binary Spotted Hyena Optimizer (BBSHO) algorithm using the Position Coordinate Vectors (PCVs) of the social behavior of spotted hyenas to achieve MUD. Further, Extremal Optimization (EO) is introduced in BBSHO algorithm to improve the local search ability within the search space. Hence, a hybrid BBSHO algorithm is proposed for achieving MUD at the receiver of the MIMO-OFDM system whose transceiver model in underwater is implemented using BELLHOP simulation system. By MATLAB simulation, it is shown that the Bit Error Rate (BER) performance of the proposed hybrid algorithm outperforms with best optimal solution within the search space towards MUD for Interference to Noise Ratio (INR) at 10 dB, 20 dB, and 40 dB over conventional detectors and metaheuristic approaches such as Binary Spotted Hyena Optimizer (BSHO), Binary Particle Swarm Optimization (BPSO) in the UWA network.

关键词： Underwater Acoustic(UWA) Orthogonal Frequency Division Multiplexing(OFDM) Multiuser Detection(MUD) Multi-Access Interference(MAI) Bionic Binary Spotted Hyena Optimizer(BBSHO) Extremal Optimization(EO)

Rare earth element(REE) geochemistry of phosphorites of the Sonrai area of Paleoproterozoic Bijawar basin,Uttar Pradesh,India

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Journal of Rare Earths 2012年第5期30卷 507-514页

作者： K.F.khan Shamim A.Dar Saif A.khan Department of Geology Aligarh Muslim UniversityAligarh-202002Uttar PradeshIndia

The rare earth element（REE） data from the Paleoproterozoic Bijawar basin,Sonrai phosphorites were used to interpret the depositional conditions of the *** post archean Australian shales（PAAS） normalized REE patterns of the Sonrai phosphorites were characterized by negative Ce and positive Eu *** rare earth elements（MREE）-enrichment was a characteristic *** showing the diagenetic effects on the REE patterns were *** observed Eu anomaly was indicative of an anoxic（or sulphate reducing） diagenetic environment of phosphate *** of sea water and upwelling during the Paleoproterozoic was responsible for the recording of positive Eu and negative Ce anomalies in the Sonrai phosphorites.

关键词： rare earth elements geochemistry phosphorites Sonrai Bijawar basin Ce anomaly Eu anomaly

Time stepping in discontinuous Galerkin method

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Journal of Hydrodynamics 2013年第3期25卷 321-329页

作者： LAI Wencong khan Abdul A Glenn Department of Civil Engineering Clemson University Clemson S.C. USA

The time discretization in the Discontinuous Galerkin （DG） scheme has been traditionally based on the Total Variation Diminishing （TVD） second-order Runge-Kutta （RK2） scheme. Computational efficiency and accuracy with the Euler Forward （EF） and the TVD second-order RK2 time stepping schemes in the DG method are investigated in this work. Numerical tests are condu- cted with the scalar Burgers equation, 1-D and 2-D shallow water flow equations. The maximum Courant number or time step size required for stability for the EF scheme and RK2 scheme with different slope limiters are compared. Numerical results show that the slope limiters affect the stability requirement in the DG method. The RK2 scheme is generally more diffusive than the EF scheme, and the RK2 scheme allows larger time step sizes. The EF scheme is found to be more efficient and accurate than the RK2 scheme in the DG method in computation.

关键词： Discontinuous Galerkin (DG) method Euler Forward (EF) scheme second-order Runge-Kutta scheme

A Seismic Hazard Map Based on Geology and Shear-wave Velocity in Rawalpindi–Islamabad,Pakistan

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Acta Geologica Sinica(English Edition) 2021年第2期95卷 659-673页

作者： Sarfraz khan Muhammad WASEEM M.Asif khan National Centre of Excellence in Geology University of Peshawar 25130KPPakistan University of Peshawar 25120 KPPakistan

The‘twin cities’district of Rawalpindi–Islamabad is among the most endangered seismic regions in Pakistan,with the seismic hazard assessed(0.32 g)to intensity IX MMI for a 475-year return period.A seismic hazard map for Rawalpindi–Islamabad is presented herein,based on 85 shear-wave velocity(VS)profiles obtained through geophysical H/V measurements and from the geological map of the *** between the average top thirty-meter shear-wave velocities(VS30)and surficial geological units have been *** peak ground acceleration(PGA)maps for 150,475 and 2475-year return periods were converted into a seismic intensity *** increments for different soils were used to compute PGA values for 150,475 and 2475-year return *** located on softer ground experienced a higher degree of damage from moderate *** to the presence of soft clay or liquefiable soil and lateral spreading,a few locations may be classified as hybrid sites class C and *** map is a critical step in facilitating code-based site classification and seismic design throughout Rawalpindi–*** the seismic hazard map based on seismic intensities is no longer used in engineering geology,it is still important in seismological analysis and for civil protection purposes.

关键词： seismic hazard site classification intensity increment engineering geology Rawalpindi-Islamabad

Strong interfacial charge transfer between hausmannite manganese oxide and alumina for efficient photocatalysis

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Chinese Journal of Chemical Engineering 2021年第5期34卷 147-159页

作者： Aisha Kanwal Shamaila Sajjad Sajjad Ahmed khan Leghari Muhammad Naeem khan International Islamic University H-10 IslamabadPakistan Pakistan Institute of Engineering and Applied Sciences Islamabad 44000Pakistan Department of Chemistry Government College of ScienceLahorePakistan

Well crystalline manganese oxide(Mn_(3)O_(4))nanoparticles anchored on gamma alumina(γ-Al_(2)O_(3))have been successfully tailored via a proficient and cost effective chemical process as an efficient material for photo *** indicated the composite formation ofγ-Al_(2)O_(3) and hausmannite structure of Mn_(3)O_(4).SEM and TEM revealed that hetero structure of Mn_(3)O_(4)/γ-Al_(2)O_(3) exhibits an amalgam of aggregated nanoparticles and *** demonstrated the chemical states of binary *** band gap tuning has been performed withγ-Al_(2)O_(3) nanoparticles by assimilating hausmannite Mn_(3)O_(4) particles into flower like microstructure of Al_(2)O_(3).The photoluminescence spectra affirmed the enhancement in charge separation in Mn_(3)O_(4)/γ-Al_(2)O_(3) binary hybrid *** band gap becomes narrow with the increase in concentrations of Mn_(3)O_(4).The narrowing of band gap is concorded with crystalline domains of primary aggregated *** elucidate the mechanism of the photocatalytic activity linear sweep voltammetry was *** results showed that Mn_(3)O_(4)/γ-Al_(2)O_(3) nanocomposite revealed the enhancement in current density as compared to pureγ-Al_(2)O_(3) which confirmed the electron transfer from Mn_(3)O_(4) toγ-Al_(2)O_(3) through the interfacial potential gradient in conduction *** optimum concentration of 6.0%Mn_(3)O_(4)/γ-Al_(2)O_(3) for hybrid structure showed an excellent photocatalytic activity under visible light due to narrow band gap *** degree distribution of Mn_(3)O_(4) nano architects overlying onγ-Al_(2)O_(3) induces a significant synergic effect betweenγ-Al_(2)O_(3) and hausmannite phase of manganese oxide(Mn_(3)O_(4)).This strong interfacial contact betweenγ-Al_(2)O_(3) and Mn_(3)O_(4) endures the quick transfer of photo generated charge carriers across interface.

关键词： Hausmannite Mn_(3)O_(4) Alumina Band gap tuning Interfacial charge transfer Nanomaterials Catalysis

A novel fractional case study of nonlinear dynamics via analytical approach

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Applied Mathematics(A Journal of Chinese Universities) 2024年第2期39卷 276-290页

作者： Hassan khan Adnan khan Rasool Shah Dumitru Baleanu Department of Mathematics Abdul Wali khan UniversityMardan 23200Pakistan Department of Mathematics Faculty of Arts and SciencesCankaya UniversityAnkara 06530Turkey Institute of Space Sciences Magurele-BucharestRomania

The present work describes the fractional view analysis of Newell-Whitehead-Segal equations,using an innovative *** work is carried with the help of the Caputo operator of fractional *** analytical solutions of some numerical examples are presented to confirm the reliability of the proposed *** derived results are very consistent with the actual solutions to the problems.A graphical representation has been done for the solution of the problems at various fractional-order ***,the solution in series form has the desired rate of convergence and provides the closed-form *** is noted that the procedure can be modified in other directions for fractional order problems.

关键词： Homotopy Perturbation method Shehu transform Newell-Whitehead-Segel Equation Caputo operator