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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

Study of a ternary blend system for bulk heterojunction thin film solar cells

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Chinese Physics B 2016年第8期25卷 94-97页

作者： Zubair ahmad Farid Touati Shakoor R A al-Thani N J Department of Electrical Engineering College of Engineering Qatar University Center for Advanced materials Qatar University

In this research, we report a bulk heterojunction（BHJ） solar cell consisting of a ternary blend system. Poly（3-hexylthiophene） P3 HT is used as a donor and [6,6]-phenyl C61-butyric acid methylester（PCBm） plays the role of acceptor whereas vanadyl 2,9,16,23-tetraphenoxy-29 H, 31H-phthalocyanine（VOPc Ph O） is selected as an ambipolar transport material. The materials are selected and assembled in such a fashion that the generated charge carriers could efficiently be transported rightwards within the blend. The organic BHJ solar cells consist of ITO/PEDOT：PSS/ternary BHJ blend/al structure. The power conversion efficiencies of the ITO/ PEDOT：PSS/P3HT：PCBm.al and ITO/PEDOT：PSS/P3HT：PCBm：VOPcPhO/al solar cells are found to be 2.3% and 3.4%, respectively.

关键词： organic semiconductor charge transport bulk heterojunction ternary blend

Changing patterns of hepatitis A prevalence within the Saudi population over the last 18 years

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World Journal of Gastroenterology 2008年第48期14卷 7371-7375页

作者： Faleh al Faleh Suliman al Shehri Saleh al Ansari mohammed al Jeffri Yaqoub al mazrou ahmad Shaffi Ayman A Abdo Department of medicine College of Medicine King Saud University ministry of Education ministry of Health Department of Community medicine College of Medicine King Saud University

AIm： To determine the seroprevalence of Hepatitis A （HAV） amongst Saudi children and compare it with previously reported prevalence data from the same population. mETHODS： A total of 1357 students were randomly selected between the ages of 16 and 18 years （689 males and 668 females） from three different regions of Saudi Arabia （madinah, AI-Qaseem, and Aseer） and tested for ***： The overall prevalence of anti-HAV-IgG among the study population was 18.6%. There was no difference between males and females but there was a significant difference in the seroprevalence （P = 0.0001） between the three different regions, with madinah region showing the highest prevalence （27.4%）. When classified according to socioeconomic status, lower class students had a prevalence of 36.6%, lower middle class 16.6%, upper middle class 9.6%, and upper class 5.9% （P = 0.0001）. Comparing the current study results with those of previous studies in 1989 and 1997 involving the same population, there was a marked reduction in the overall prevalence of HAV from 52% in 1989, to 25% in 1997, to 18.6% in 2008 （P 〈 0.0001）.CONCLUSION： Over the last 18 years, there has been a marked decline in the prevalence of HAV in Saudi children and adolescents. The current low prevalence rates call for strict adherence to vaccination policies in high-risk patients and raises the question of a universal HAV vaccination program.

关键词： Hepatitis A Saudi Arabia Epidemiology Prevalence Serology

Precipitation Study in Inconel 625 alloy by Positron Annihilation Spectroscopy

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Journal of materials Science & Technology 2003年第5期19卷 434-436页

作者： m.ahmad. W.ahmad. m.A.Shaikh mahmud ahmad m.U.Rajput Nuclear Physics Division Pakistan Institute of Nuclear Science & Technology P.O. Nilore Islamabad PakistanNuclear Physics Division Pakistan Institute of Nuclear Science & Technology P.O. Nilore Islamabad PakistanNuclear Physics Division Pakistan Institute of Nuclear Science & Technology P.O. Nilore Islamabad PakistanNuclear Physics Division Pakistan Institute of Nuclear Science & Technology P.O. Nilore Islamabad Pakistan Nuclear Physics Division Pakistan Institute of Nuclear Science & Technology P.O. Nilore Islamabad Pakistan

Precipitation in Inconel 625 alloy has been studied by positron annihilation spectroscopy and electron microscopy. The observed dependence of annihilation characteristics on aging time is attributed to the change of the positron state due to the increase and decrease of the density and size of the 7' precipitates. Hardness measurements and lifetime measurements are in good agreement.

关键词： Positron lifetime Precipitation Inconel 625 alloy Fast-fast coincidence system Hardness

Cloud Datacenter Selection Using Service Broker Policies:A Survey

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Computer modeling in Engineering & Sciences 2024年第4期139卷 1-41页

作者： Salam.al-E’mari Yousef Sanjalawe ahmad al-Daraiseh mohammad Bany Taha mohammad aladaileh Department of Information Security Faculty of ITUniversity of PetraAmman11196Jordan Department of Cybersecurity School of ITAmerican University of Madaba(AUM)Amman11821Jordan Department of Computer Science School of ITAmerican University of Madaba(AUM)Amman11821Jordan Department of Data Science and Artificial Intelligence School of ITAmerican University of Madaba(AUM)Amman11821Jordan

Amid the landscape of Cloud Computing(CC),the Cloud Datacenter(DC)stands as a conglomerate of physical servers,whose performance can be hindered by bottlenecks within the realm of proliferating CC services.A linchpin in CC’s performance,the Cloud Service Broker(CSB),orchestrates DC *** to adroitly route user requests with suitable DCs transforms the CSB into a bottleneck,endangering service *** tackle this,deploying an efficient CSB policy becomes imperative,optimizing DC selection to meet stringent Qualityof-Service(QoS)*** numerous CSB policies,their implementation grapples with challenges like costs and *** article undertakes a holistic review of diverse CSB policies,concurrently surveying the predicaments confronted by current *** foremost objective is to pinpoint research gaps and remedies to invigorate future policy ***,it extensively clarifies various DC selection methodologies employed in CC,enriching practitioners and researchers *** synthetic analysis,the article systematically assesses and compares myriad DC selection *** analytical insights equip decision-makers with a pragmatic framework to discern the apt technique for their *** summation,this discourse resoundingly underscores the paramount importance of adept CSB policies in DC selection,highlighting the imperative role of efficient CSB policies in optimizing CC *** emphasizing the significance of these policies and their modeling implications,the article contributes to both the general modeling discourse and its practical applications in the CC domain.

关键词： Cloud computing cloud service broker datacenter selection quality-of-service user request

Video Games Localization into Arabic:Gamers’Reactions to Localizing PUBG and Free Fire

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Journal of Social Computing 2023年第1期4卷 74-93页

作者： Shatha Jarrah Saleh al-Salman ahmad S Haider Department of English Language and Translation Applied Science Private UniversityAmman 11937Jordan mEU Research Unit Middle East UniversityAmman 11831Jordan

The middle East and North Africa(mENA)region has an active gaming community,with Arab gamers being reliant on games produced in Europe,America,and Japan due to the lack of significant game production companies in the mENA *** study explores the gamers’reactions to the localization process of two video games,namely PUBG and Free *** data collection purposes,a five-point Likert scale questionnaire that consisted of 18 items and six constructs,namely need for subtitled games,technical aspects,language issues,language preference,attitudes to game localization,and future actions and recommendations,was designed to elicit the reactions of 112 *** analyzing the responses,the findings showed that the better the technical aspects and language issues of the games’performance,the more positive participants’attitudes to game *** study recommends that further research could be conducted on the localization of video games with different themes into Arabic.

关键词： localization video games PUBG Free Fire Audio Visual Translation(AVT)

Improved signal de-noising in underwater acoustic noise using S-transform: A performance evaluation and comparison with the wavelet transform

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Journal of Ocean Engineering and Science 2017年第3期2卷 172-185页

作者： Yasin Yousif al-Aboosi ahmad Zuri Sha’ameri Faculty of Electrical Engineering Universiti Teknologi MalaysiaSkudai 81300JohorMalaysia Faculty of Engineering University of MustansiriyahBaghdadIraq

Sound waves propagate well underwater making it useful for target locating and *** acoustic noise(UWAN)affects the reliability in applications where the noise comes from multiple *** this paper,a novel signal de-noising technique is proposed using *** the time-frequency representation,de-noising is performed using soft thresholding with universal threshold estimation which is then *** UWAN used for the validation is sea truth data collected at Desaru beach on the eastern shore of Johor in malaysia with the use of broadband *** comparison is made with the more conventionally used wavelet transform de-noising *** types of signals are evaluated:fixed frequency signals and time-varying *** results demonstrate that the proposed method shows better signal to noise ratio(SNR)by 4 dB and lower root mean square error(RmSE)by 3 dB achieved at the Nyquist sampling frequency compared to the previously proposed de-noising method like wavelet transform.

关键词： Underwater acoustic noise Time-frequency analysis Wavelet transforms S-transforms Signal de-noising

Zinc Oxide Nanostructures for NO_2 Gas–Sensor Applications:A Review

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Nano-micro Letters 2015年第2期7卷 97-120页

作者： Rajesh Kumar O.al-Dossary Girish Kumar ahmad Umar PG Department of Chemistry JCDAV College Department of Physics King Saud University Department of Chemistry Faculty of Arts and Sciences Najran University Promising Centre for Sensors and Electronic Devices (PCSED) Najran University

Because of the interesting and multifunctional properties,recently,ZnO nanostructures are considered as excellent material for fabrication of highly sensitive and selective gas ***,ZnO nanomaterials are widely used to fabricate efficient gas sensors for the detection of various hazardous and toxic *** presented review article is focusing on the recent developments of NO2gas sensors based on ZnO *** review presents the general introduction of some metal oxide nanomaterials for gas sensing application and finally focusing on the structure of ZnO and its gas sensing *** gas sensing characteristics such as gas response,response time,recovery time,selectivity,detection limit,stability and recyclability,etc are also discussed in this ***,the utilization of various ZnO nanomaterials such as nanorods,nanowires,nano-micro flowers,quantum dots,thin films and nanosheets,etc for the fabrication of NO2gas sensors are also ***,various factors such as NO2concentrations,annealing temperature,ZnO morphologies and particle sizes,relative humidity,operating temperatures which are affecting the NO2gas sensing properties are discussed in this ***,the review article is concluded and future directions are presented.

关键词： ZnO nanostructure Gas sensors Sensor parameters Sensor mechanism

Techno-economic analysis of green hydrogen as an energy-storage medium for commercial buildings

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Clean Energy 2023年第1期7卷 84-98页

作者： Rahul Rajeevkumar Urs Assia Chadly Ameena al Sumaiti ahmad mayyas Department of Industrial and Systems Engineering Khalifa UniversityAbu Dhabi 127788UAE Department of Electrical Engineering and Computer Science Advanced Power and Energy CenterKhalifa UniversityAbu Dhabi 127788UAE

Green-hydrogen production is vital in mitigating carbon emissions and is being adopted *** its transition to a more diverse energy mix with a bigger share for renewable energy,United Arab Emirates(UAE)has committed to investing billions of dollars in the production of green *** study presents the results of the techno-economic assessment of a green-hydrogen-based commercial-building microgrid design in the *** microgrid has been designed based on the building load demand,green-hydrogen production potential utilizing solar photovoltaic(PV)energy and discrete stack reversible fuel cell electricity generation during non-PV *** the current market conditions and the hot humid climate of the UAE,a performance analysis is derived to evaluate the technical and economic feasibility of this *** study aims at maximizing both the building microgrid’s independence from the main grid and its renewable *** results indicate that the designed system is capable of meeting three-quarters of its load demand independently from the main grid and is supported by a 78%renewable-energy *** economic analysis demonstrates a 3.117-$/kg levelized cost of hydrogen production and a 0.248-$/kWh levelized cost for storing hydrogen as ***,the levelized cost of system energy was found to be less than the current utility costs in the *** analysis shows the significant impact of the capital cost and discount rate on the levelized cost of hydrogen generation and storage.

关键词： fuel cell electrolyser green hydrogen microgrid photovoltaic