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Detailed analysis of the relativistic configuration of Bardeen anisotropic spheres in modified f(G)gravity

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Communications in Theoretical Physics 2024年第6期76卷 45-56页

作者： Adnan malik Ayesha Almas Tayyaba Naz Rubab manzoor m Z bhatti School of mathematical Sciences Zhejiang Normal UniversityJinhuaZhejiangChina Department of mathematics University of Management and TechnologySialkot CampusLahorePakistan National University of Computer and Emerging Sciences Lahore CampusPakistan Department of mathematics University of Management and TechnologyJohar Town CampusLahore 54782Pakistan Department of mathematics University of the PunjabQuaid-i-Azam CampusLahore-54590Pakistan

The aim of this work is to investigate anisotropic compact objects within the framework of f(G)modified theory of *** our present work,we utilize Krori-Barua metrics,i.e.,λ(r)=Xr^(2)+Y andβ(r)=Zr^(2).We use some matching conditions of spherically symmetric spacetime with Bardeen's model as an exterior ***,we establish some expressions of energy density and pressure components to analyze the stellar configuration of Bardeen compact stars by assuming viable f(G)*** examine the energy conditions for different stellar structures to verify the viability of our considered ***,we also investigate some other physical features,such as equilibrium condition,equation of state parameters,adiabatic index,stability analysis,mass function,surface redshift,and compactness factor,*** is worthwhile to mention here for the current study that our stellar structure in the background of Bardeen's model is more viable and stable.

关键词： Bardeen compact stars f(G)modified gravity Krori-Barua potential

双制式列车接地系统的车-地联合牵引供电计算

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西南交通大学学报 2024年第3期59卷 501-509页

作者：刘炜杨凌云马庆安李雪飞 bhatti Ashfaque Ahmed 西南交通大学电气工程学院四川成都611730 中车长春轨道客车股份有限公司吉林长春130062

为研究双制式列车在不同供电制式区段下的车体环流和车体—轴端电位分布,针对某型双制式列车构建列车接地系统的链式电路模型,并提出车-地一体化的交、直流区段联合牵引供电计算方法;同时,建立列车接地保护电阻优化模型,并分析2种列车... 详细信息

为研究双制式列车在不同供电制式区段下的车体环流和车体—轴端电位分布,针对某型双制式列车构建列车接地系统的链式电路模型,并提出车-地一体化的交、直流区段联合牵引供电计算方法;同时,建立列车接地保护电阻优化模型,并分析2种列车接地系统配置方案.以国内某条双制式线路为算例进行仿真验证,研究结果表明:方案1相较方案2,列车的车体—轴端电位最大值降低36.58%~41.04%,车体环流最大值降低18.49%~22.97%;并且在方案1中,头尾车保护电阻设置为20 mΩ,可使列车的车体—轴端电位最大值为1.15 V,车体电流最大值为50.30 A,达到抑制车体—轴端电位的最优效果.该车-地一体化的交、直流区段联合牵引供电计算方法可适用于单一供电制式或者多供电制式列车接地系统的分析.

关键词：双制式列车联合牵引供电计算列车接地系统链式电路车体环流

Thin-shell wormholes and modified Chaplygin gas with relativistic corrections

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Communications in Theoretical Physics 2023年第12期75卷 84-96页

作者： m Z bhatti Z Yousaf m Yousaf Department of mathematics University of the PunjabQuaid-i-Azam CampusLahore-54590Pakistan

In this paper,we analyze thin-shell wormholes from two identical copies of charged static cylindrically symmetric spacetimes using Visser’s‘cut and paste’approach under the influence of f(R,T)gravity Harko,Lobo,Nojiri,and Odintsov(2011,***.D 84,024020).In this scenario,the modified Chaplygin gas supports the exotic matter in the shell which allows,one to examine the dynamics of constructed *** utilize the junction condition to connect the interior and exterior geometries across the hypersurface and calculate different components of the Lanczos equation recently computed by Roza in Rosa(2021,***.D 103,104069).We analyze the stability of the thin-shell wormhole models under linear perturbations while keeping the cylindrical symmetry and also examine the influence of charge on their *** positive quantity of the second derivative of potential at the throat radius might be interpreted as the stability *** find both unstable and stable wormhole solutions for different parameters included in the equation of state and specific forms of considered gravity and illustrate them theoretically as well as *** examine the impact of electric charge on the stability region of a constructed wormhole,which suggests that a wormhole model with a charge may exhibit more stable behavior compared to an uncharged system.

关键词： wormholes gravitation mathematical and relativistic aspects of cosmology

Complexity of charged anisotropic spherically symmetric fluids in f(G)gravity

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Communications in Theoretical Physics 2023年第3期75卷 91-104页

作者： Z Yousaf m Z bhatti m m m Nasir Department of mathematics University of the PunjabQuaid-i-Azam CampusLahore-54590Pakistan

The previous ideology of complexity factor for the dynamical spheres[Herrera et al 2018,***.D,98,104059]is extended for the influence of charge.A dynamical spherically symmetric non-dissipative and dissipative self-gravitating structure is examined in the presence of maxwell f(G)gravity to examine the complexity *** pattern of evolution is studied with the minimal complexity *** complexity factor remains the same for the structure of fluid distribution,while we examine homologous constraints for the most basic evolution *** calculate the structure scalars which play an important role in order to understand the fundamental properties of the *** fluid is geodesic as well as shearing for the dissipative case and there is a large number of *** the non-dissipative fluid distribution,a shear-free,homogeneous and isotropic,geodesic fluid correlates with the evolving homologous and vanishing complexity *** implication of the condition of vanishing complexity factor and stability are discussed at the end.

关键词： gravitation anisotropy complexity hydrodynamics

magnetohydrodynamics hemodynamics hybrid nanofluid flow through inclined stenotic artery

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Applied mathematics and mechanics(English Edition) 2023年第3期44卷 459-476页

作者： B.K.SHARmA R.GANDHI T.ABBAS m.m.bhatti Department of mathematics Birla Institute of Technology and SciencePilani 333031India Department of mathematics Division of Science and TechnologyUniversity of EducationLahore 54770Pakistan College of mathematics and Systems Science Shandong University of Science and TechnologyQingdao 266590Shandong ProvinceChina

The present study aims to perform computational simulations of twodimensional(2D)hemodynamics of unsteady blood flow via an inclined overlapping stenosed artery employing the Casson fluid model to discuss the hemorheological properties in the arterial region.A uniform magnetic field is applied to the blood flow in the radial direction as the magneto-hemodynamics effect is *** entropy generation is discussed using the second law of *** influence of different shape parameters is explored,which are assumed to have varied shapes(spherical,brick,cylindrical,platelet,and blade).The Crank-Nicolson scheme solves the equations and boundary conditions governing the *** a given critical height of the stenosis,the key hemodynamic variables such as velocity,wall shear stress(WSS),temperature,flow rate,and heat transfer coefficient are computed.

关键词： overlapping stenosis hematocrit-dependent viscosity Au-Cu/blood hybrid nanofluid entropy generation shape effect

A multi-modal Deep Learning Approach for Emotion Recognition

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Intelligent Automation & Soft Computing 2023年第5期36卷 1561-1570页

作者： H.m.Shahzad Sohail masood bhatti Arfan Jaffar muhammad Rashid The Superior University LahorePakistan National University of Technology IslamabadPakistan Intelligent Data Visual Computing Research(IDVCR) LahorePakistan

In recent years,research on facial expression recognition(FER)under mask is *** a mask for protection from Covid 19 has become a compulsion and it hides the facial expressions that is why FER under the mask is a difﬁcult *** prevailing unimodal techniques for facial recognition are not up to the mark in terms of good results for the masked face,however,a multi-modal technique can be employed to generate better *** proposed a multi-modal methodology based on deep learning for facial recognition under a masked face using facial and vocal *** multimodal has been trained on a facial and vocal *** have used two standard datasets,m-LFW for the masked dataset and CREmA-D and TESS dataset for vocal *** vocal expressions are in the form of audio while the faces data is in image form that is why the data is *** order to make the data homogeneous,the voice data is converted into images by taking spectrogram.A spectrogram embeds important features of the voice and it converts the audio format into the ***,the dataset is passed to the multimodal for *** network and the experimental results demonstrate that the proposed multimodal algorithm outsets unimodal methods and other state-of-the-art deep neural network models.

关键词： Deep learning facial expression recognition multi-model neural network speech emotion recognition spectrogram covid-19

Hydrodynamics and Heat Transfer Analysis of Airflow in a Sinusoidally Curved Channel

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Computers, materials & Continua 2022年第6期71卷 4835-4853页

作者： Abid.A.memon m.Asif memon Kaleemullah bhatti Thanin Sitthiwirattham Nichaphat Patanarapeelert Department of mathematics and Social Sciences Sukkur IBA UniversitySukkur65200SindhPakistan mathematics Department Faculty of Science and TechnologySuan Dusit UniversityBangkok10300Thailand Department of mathematics Faculty of Applied ScienceKing Mongkut’s University of Technology North BangkokBangkok10800Thailand

For heat transfer enhancement in heat exchangers,different types of channels are often *** performance of heat exchangers can be made better by considering geometry composed of sinusoidally curved *** research studies the modeling and simulation of airflow through a 2πunits long sinusoidally curved wavy *** the purpose,two-dimensional Navier Stokes equations along with heat equations are under *** simulate the fluid flow problem,the finite element-based software COmSOL multiphysics 5.4 is *** parametric study for Reynolds number from Re=100 to Re=1000 and the period of vibration P from 0 to 5 are *** surface plots,streamline patterns,contours,and graphs are presented for the velocity field magnitude,temperature,and pressure against the Reynolds number as well as period of *** results are compared with various *** is found that due to the creation of periodic contraction regions the velocity magnitude of the flow is continuously increasing with the increase of Reynolds number,on the contrary the pressure is decreasing from inlet to outlet of the ***,a periodic variation in the pressure distribution along the vibrating boundaries has been found with an average increase of 500%for the high Reynolds number.A novel work was done by expressing the rotation rate per second in terms of local Reynolds number for the recirculating regions found due to the periodic oscillation of the *** average temperature near the outlet where a fixed temperature is imposed initially is decreasing with an increase in Reynolds *** convection process is weakened due to an increase of periodic vibration of boundaries.

关键词： Simulation of fluid flow heat transfer cosine function wavy channel

Simulation of Non-Isothermal Turbulent Flows Through Circular Rings of Steel

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Computers, materials & Continua 2022年第3期70卷 4341-4355页

作者： Abid.A.memon m.Asif memon Kaleemullah bhatti Kamsing Nonlaopon Ilyas Khan Department of mathematics and Social Sciences Sukkur IBA UniversitySukkur65200SindhPakistan Department of mathematics Faculty of ScienceKhon Kaen UniversityKhon Kaen40002Thailand Department of mathematics College of Science Al-ZulfiMajmaah UniversityAl-Majmaah11952Saudi Arabia

This article is intended to examine the fluid flow patterns and heat transfer in a rectangular channel embedded with three semi-circular cylinders comprised of steel at the *** an organization is used to generate the heat exchangers with tube and shell because of the production of more turbulence due to zigzag path which is in favor of rapid heat *** of little maintenance,the heat exchanger of such type is extensively ***,we generate simulation of flow and heat transfer using nonisothermal flow interface in the Comsol multiphysics 5.4 which executes the Reynolds averaged Navier stokes equation(RANS)model of the turbulent flow together with heat *** is tested with Prandtl number(Pr=0.7)with inlet velocity magnitude in the range from 1 to 2 m/sec which generates the Reynolds number in the range of 2.2×10^(5) to 4.4×10^(5) with turbulence kinetic energy and the dissipation rate in ranges(3.75×10^(−3) to 1.5×10^(−2))and(3.73×10^(−3)−3×10^(−2))*** correlations available in the literature are used in order to check *** results are displayed through streamlines,surface plots,contour plots,isothermal lines,and *** is concluded that by retaining such an arrangement a quick distribution of the temperature over the domain can be seen and also the velocity magnitude is increasing from 333.15%to a maximum of 514%.The temperature at the middle shows the consistency in value but declines immediately at the *** process becomes faster with the decrease in inlet velocity magnitude.

关键词： Incompressible turbulent flow heat transfer non-isothermal finite element method energy equation

Raising capital amid economic policy uncertainty:an empirical investigation

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Financial Innovation 2022年第1期8卷 2013-2044页

作者： Dawood Ashraf mohsin Khawaja m.Ishaq bhatti Islamic Development Bank Institute(A member of Islamic Development Bank Group) 8111 King Khalid StreetJeddah 22332-2444Saudi Arabia School of Business Studies Institute of Business Administration(IBA)KarachiPakistan S P Jain School of Global management SydneyNSW 2141Australia La Trobe Business School La Trobe UniversityMelbourneAustralia

This paper investigates how economic policy uncertainty affects firms’frequency and their choice of financial instruments to raise *** applying a three-step sequential framework over a sample of 6834 publicly listed US non-financial firms,we find that during periods of high economic uncertainty,firms raise capital more frequently with a preference toward debt *** empirical findings suggest that firms prefer debt financing over equity financing to avoid ownership dilution and high equity *** rise in leverage during periods of high economic uncertainty highlights the importance of scrutinizing policy tools used to stabilize the economy during such times.

关键词： Economic policy uncertainty Political uncertainty Capital issuance Debt and equity markets Ownership structure Governance mechanisms