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A regular MOG black hole's impact on shadows and gravitational weak lensing in the presence of a quintessence field

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Communications in Theoretical Physics 2024年第8期76卷 91-102页

作者： Ahmad Al-Badawi sanjar shaymatov Mirzabek Alloqulov Anzhong Wang Department of Physics Al-Hussein Bin Talal UniversityPO Box:2071111Ma’anJordan Institute for Theoretical Physics and Cosmology Zhejiang University of TechnologyHangzhou 310023China Tashkent State Technical University Tashkent 100095Uzbekistan University of Tashkent for Applied Sciences Str.Gavhar 1Tashkent 100149Uzbekistan New Uzbekistan University Movarounnahr Street 1Tashkent 100000Uzbekistan Institute of Fundamental and Applied Research National Research University TIIAMEKori Niyoziy 39Tashkent 100000Uzbekistan GCAP-CASPER Physics DepartmentBaylor UniversityWacoTX 76798-7316United States of America

We investigate the impact of the modified gravity(MOG)field and the quintessence scalar field on horizon evolution,black hole(BH)shadow and the weak gravitational lensing around a static spherically symmetric *** first begin to write the BH metric associated with the MOG parameter and quintessence scalar *** then determine the BH shadow and obtain numerical solutions for the photon sphere and shadow *** show that the MOG(α)and the quintessence(c)parameters have a significant impact on the BH shadow and photon *** on the analysis,we further show that the combined effects of the MOG parameter and quintessence field can increase the values of BH shadow and photon sphere *** also obtain constraints on the BH parameters by applying the observational data of Sgr A^(★)and M87^(★).Finally,we consider the weak deflection angle of BH within the context of the Gauss-Bonnet theorem(GBT)and show that the combined effects of the MOG and quintessence parameters do make the value of the deflection angle increase,and find this remarkable property is in good agreement with the physical meaning of both parameters that can maintain the strong gravitational field in the surrounding environment of a BH.

关键词： modified gravity shadows gravitational weak lensing quintessence field

Radiation properties of the accretion disk around a black hole in Einstein-Maxwell-scalar theory

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Chinese Physics C 2024年第2期48卷 162-170页

作者： Mirzabek Alloqulov sanjar shaymatov Bobomurat Ahmedov Abdul Jawad New Uzbekistan University Movarounnahr street 1Tashkent 100000Uzbekistan Institute of Fundamental and Applied Research National Research University TIIAMEKori Niyoziy 39Tashkent 100000Uzbekistan University of Tashkent for Applied Sciences Str.Gavhar 1Tashkent 100149Uzbekistan Institute for Theoretical Physics and Cosmology Zhejiang University of TechnologyHangzhou 310023China Central Asian University Milliy Bog Street 264Tashkent 111221Uzbekistan National University of Uzbekistan Tashkent 100174Uzbekistan Power Engineering Faculty Tashkent State Technical UniversityTashkent 100095Uzbekistan Ulugh Beg Astronomical Institute Astronomy St 33Tashkent 100052Uzbekistan Institute of Theoretical Physics National University of UzbekistanTashkent 100174Uzbekistan Department of Mathematics COMSATS University IslamabadLahore CampusLahore-54000Pakistan

In this study,we explore the properties of a non-rotating black hole in the Einstein-Maxwell-scalar(EMS)theory and investigate the luminosity of the accretion disk surrounding *** determine all the orbital parameters of particles in the accretion disk,including the radius of the innermost stable circular orbit(ISCO)with angular velocity,angular momentum,and ***,we study the radiative efficiency for different values of black hole ***,we analyze the flux,differential luminosity,and temperature of the accretion disk.

关键词： Einstein-Maxwell-scalar theory black hole accretion disk

Shadows and gravitational weak lensing by the Schwarzschild black hole in the string cloud background with quintessential field

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Chinese Physics C 2022年第12期46卷 321-332页

作者： G.Mustafa Farruh Atamurotov Ibrar Hussain sanjar shaymatov Ali Övgün Department of Physics Zhejiang Normal UniversityJinhua 321004China Inha University in Tashkent Ziyolilar 9Tashkent 100170Uzbekistan Akfa University Milliy Bog Street 264Tashkent 111221Uzbekistan National University of Uzbekistan Tashkent 100174Uzbekistan Tashkent State Technical University Tashkent 100095Uzbekistan School of Electrical Engineering and Computer Science National University of Sciences and TechnologyH-12IslamabadPakistan Samarkand State University University Avenue 15Samarkand 140104Uzbekistan Ulugh Beg Astronomical Institute Astronomicheskaya 33Tashkent 100052Uzbekistan Institute of Fundamental and Applied Research National Research University TIIAMEKori Niyoziy 39Tashkent 100000Uzbekistan Physics Department Eastern Mediterranean UniversityFamagusta99628 North Cyprus via Mersin 10Turkey

In this study,we observe that,in the presence of the string cloud parameter a and the quintessence parameterγ,with the equation of state parameter,ω_(q) = -2/3the radius of the shadow of the Schwarzschild black hole increases as compared with that in the pure Schwarzschild black hole *** existence of both quintessential dark energy and the cloud of strings increases the shadow size;hence,the strength of the gravitational field around the Schwarzschild black hole *** the data collected by the Event Horizon Telescope(EHT)collaboration for M87*and Sgr A*,we obtain upper bounds on the values of a andγ.Further,we see the effects of a andγon the rate of emission energy for the Schwarzschild black *** notice that the rate of emission energy is higher in the presence of clouds of strings and ***,we study the weak deflection angle using the Gauss-Bonnet *** show the influence of a andγon the weak deflection *** notice that both a andγincrease the deflection angleα.

关键词： shadow gravitational Lensing string cloud quintessence Schwarzschild black hole

Real-Time Object Detection and Face Recognition Application for the Visually Impaired

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Computers, Materials & Continua 2024年第6期79卷 3569-3583页

作者： Karshiev sanjar Soyoun Bang SookheeRyue Heechul Jung Department of Artificial Intelligence Kyungpook National UniversityDaegu41466Republic of Korea Haga Co. Ltd.Daegu38428Republic of Korea

The advancement of navigation systems for the visually impaired has significantly enhanced their mobility by mitigating the risk of encountering obstacles and guiding them along safe,navigable *** approaches primarily focus on broad applications such as wayfinding,obstacle detection,and fall ***,there is a notable discrepancy in applying these technologies to more specific scenarios,like identifying distinct food crop types or recognizing *** study proposes a real-time application designed for visually impaired individuals,aiming to bridge this research-application *** introduces a system capable of detecting 20 different food crop types and recognizing faces with impressive accuracies of 83.27%and 95.64%,*** results represent a significant contribution to the field of assistive technologies,providing visually impaired users with detailed and relevant information about their surroundings,thereby enhancing their mobility and ensuring their ***,it addresses the vital aspects of social engagements,acknowledging the challenges faced by visually impaired individuals in recognizing acquaintances without auditory or tactile signals,and highlights recent developments in prototype systems aimed at assisting with face recognition *** comprehensive approach not only promises enhanced navigational aids but also aims to enrich the social well-being and safety of visually impaired communities.

关键词： Artificial intelligence deep learning real-time object detection application

Prediction of malaria cases in the southeastern Iran using climatic variables:An 18-year SARIMA time series analysis

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Asian Pacific Journal of Tropical Medicine 2021年第10期14卷 463-471页

作者： Hamid Reza Tohidinik Hossein Keshavarz Mehdi Mohebali Mandana sanjar Gholamreza Hassanpour HIV/STI Surveillance Research Center and WHO Collaborating Center for HIV SurveillanceInstitute for Futures Studies in HealthKerman University of Medical SciencesKermanIran Center for Research of Endemic Parasites of Iran(CREPI) Tehran University of Medical SciencesTehranIran Department of Medical Parasitology&Mycology School of Public HealthTehran University of Medical SciencesTehranIran

Objective:To predict future trends in the incidence of malaria cases in the southeast of Iran as the most important area of malaria using Seasonal Autoregressive Integrated Moving Average(SARIMA)model,and to check the effect of meteorological variables on the disease ***:SARIMA method was applied to fit a model on malaria incidence from April 2001 to March 2018 in Sistan and Baluchistan province in southeastern *** variables such as temperature,rainfall,rainy days,humidity,sunny hours and wind speed were also included in the multivariable model as ***,the best fitted model was adopted to predict the number of malaria cases for the next 12 ***:The best-fitted univariate model for the prediction of malaria in the southeast of Iran was SARIMA(1,0,0)(1,1,1)12[Akaike Information Criterion(AIC)=307.4,validation root mean square error(RMSE)=0.43].The occurrence of malaria in a given month was mostly related to the number of cases occurring in the previous 1(p=1)and 12(P=1)*** inverse number of rainy days with 8-month lag(β=0.3292)and temperature with 3-month lag(β=-0.0026)were the best predictors that could improve the predictive performance of the univariate ***,SARIMA(1,0,0)(1,1,1)12 including mean temperature with a 3-month lag(validation RMSE=0.414)was selected as the final multivariable ***:The number of malaria cases in a given month can be predicted by the number of cases in the prior 1 and 12 *** number of rainy days with an 8-month lag and temperature with a 3-month lag can improve the predictive power of the model.

关键词： Malaria Time series SARIMA Forecasting Climate Iran

Substrates for clinical applicability of stem cells

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World Journal of Stem Cells 2015年第2期7卷 243-252页

作者： sanjar Enam Sha Jin Department of Biomedical Engineering Thomas J Watson School of Engineering and Applied SciencesState University of New York in Binghamton

The capability of human pluripotent stem cells(h PSCs) to differentiate into a variety of cells in the human body holds great promise for regenerative medicine. Many substrates exist on which h PSCs can be self-renewed, maintained and expanded to further the goal of clinical application of stem cells. In this review, we highlight numerous extracellular matrix proteins, peptide and polymer based substrates, scaffolds and hydrogels that have been pioneered. We discuss their benefits and shortcomings and offer future directions as well as emphasize commercially available synthetic peptidesas a type of substrate that can bring the benefits of regenerative medicine to clinical settings.

关键词： Human pluripotent stem cells Extracellularmatrix protein Synthetic substrate Peptide Polymer Scaffold Hydrogel

Problems,assumptions and solutions in locomotive design,traction and operational studies

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Railway Engineering Science 2022年第3期30卷 265-288页

作者： Maksym Spiryagin Qing Wu Oldrich Polach John Thorburn Wenhsi Chua Valentyn Spiryagin Sebastian Stichel Sundar Shrestha Esteban Bernal sanjar Ahmad Colin Cole Tim McSweeney Centre for Railway Engineering Central Queensland UniversityRockhampton 4702Australia Independent Consultant Neuhausen am RheinfallSwitzerland Progress Rail NewcastleAustralia BHP Port HedlandAustralia Engineering Centre for Railway Transport SkolkovoRussian Federation KTH Royal Institute of Technology StockholmSweden

Locomotive design is a highly complex task that requires the use of systems engineering that depends upon knowledge from a range of disciplines and is strongly oriented on how to design and manage complex systems that operate under a wide range of different train operational conditions on various types of *** that field investigation programs for locomotive operational scenarios involve high costs and cause disruption of train operations on real railway networks and given recent developments in the rollingstock compliance standards in Australia and overseas that allow the assessment of some aspects of rail vehicle behaviour through computer simulations,a great number of multidisciplinary research studies have been performed and these can contribute to further improvement of a locomotive design technique by increasing the amount of computer-based *** paper was focused on the presentation of the all-important key components required for locomotive studies,starting from developing a realistic locomotive design model,its validation and further applications for train *** integration of all engineering disciplines is achieved by means of advanced simulation approaches that can incorporate existing AC and DC locomotive designs,hybrid locomotive designs,full locomotive traction system models,rail friction processes,the application of simplified and exact wheel-rail contact theories,wheel-rail wear and rolling contact fatigue,train dynamic behaviour and intrain forces,comprehensive track infrastructure details,and the use of co-simulation and parallel *** cosimulation and parallel computing approaches that have been implemented on Central Queensland University’s High-Performance Computing cluster for locomotive studies will be *** confidence in these approaches is based on specific validation procedures that include a locomotive model acceptance procedure and field test *** problems and limitations presented in locomot

关键词： Locomotive Design Simulation Virtual prototyping Digital twin Traction Braking Wheel-rail wear Damage

A Method to Reduce the Lehmer Measure in a Multi-Term Machin-Like Formula for π

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Open Journal of Applied Sciences 2022年第8期12卷 1477-1493页

作者： sanjar M. Abrarov Rehan Siddiqui Rajinder K. Jagpal Brendan M. Quine Epic College of Technology Mississauga Canada York University Toronto Canada

Previously we have proposed a new method of transforming quotients into integer reciprocals in the Machin-like formulas for π. As a further development, here we show how to generate a multi-term Machin-like formula f... 详细信息

关键词： Constant Pi Machin-Like Formula Lehmer’s Measure

Efficient Application of the Radiance Enhancement Method for Detection of the Forest Fires Due to Combustion-Originated Reflectance

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Journal of Environmental Protection 2021年第10期12卷 717-733页

作者： Rehan Siddiqui Rajinder K. Jagpal sanjar M. Abrarov Brendan M. Quine Epic College of Technology Mississauga Canada Department of Earth and Space Science and Engineering York University Toronto Canada Department of Physics and Astronomy York University Toronto Canada Thoth Technology Inc. Algonquin Radio Observatory Pembroke Ontario Canada

The existing methods for detection of the cloud scenes are applied at relatively small spectral range within shortwave upwelling radiative wavelength flux. We have reported a new method for detection of the cloud scenes based on the Radiance Enhancement (RE). This method can be used to cover a significantly wider spectral range from 1100 nm to 1700 nm by using datasets from the space-orbiting micro-spectrometer Argus 1000. Due to high sunlight reflection of the smoke originated from the forest or field fires the proposed RE method can also be implemented for detection of combustion aerosols. This approach can be a promising technique for efficient detection and continuous monitor of the seasonal forest and field fires. To the best of our knowledge this is the first report showing how a cloud method can be generalized for efficient detection of the forest fires due to combustion-originated reflectance.

关键词： Radiance Enhancement Clouds Forest Fire Radiative Transfer Model Line-By-Line Calculation Micro-Spectrometer