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Development of multi-physics numerical simulation model to investigate thermo-mechanical fatigue crack propagation in an autofrettaged gun barrel

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Defence Technology（防务技术） 2021年第5期17卷 1579-1591页

作者： Naveed Hussain faisal Qayyum Riffat Asim Pasha Masood Shah Department of Mechanical Engineering University of Engineering and TechnologyTaxilaPakistan Institut für Metallformung Technische Universitat BeragakademieFreibergGermany

In this research,a detailed multi-physics study has been carried out by numerically simulating a solid fractured gun barrel for 20 thermo-mechanical *** numerical model is based on thermal effects,mechanical stress fields and fatigue crack ***-plastic material data of modified AISI 4340 at temperatures ranging from 25 to 1200℃and at strain rates of 4,16,32 and 48 s^(-1) was acquired from high-temperature compression *** was used as material property data in the simulation *** boundary conditions applied are kept similar to the working gun barrel during continuous firing.A methodology has been provided to define thermo-mechanically active surface-to-surface type interface between the crack faces for a better approximation of stresses at the crack *** of results from non-autofrettaged and autofrettaged simulation models provide useful information about the evolution of strains and stresses in the barrel at different points under combined thermo-mechanical loading cycles in both *** effect of thermal fatigue under already induced compressive yield due to autofrettage and the progressive degradation of the accumulated stresses due to thermo-mechanical cyclic loads on the internal surface of the gun barrel(mimicking the continuous firing scenario)has been *** between energy release rate at tips of varying crack lengths due to cyclic thermo-mechanical loading in the non-autofrettaged and autofrettaged gun has been carried out.

关键词： Steel Autofrettage Gun barrel Crack propagation Thermo-mechanical fatigue Numerical simulation Residual stress dissipation

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Blockchain Based Secured Load Balanced Task Scheduling Approach for fitness Service

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Computers, Materials & Continua 2022年第5期71卷 2599-2616页

作者： Muhammad Ibrahim faisal Jamil YunJung Lee DoHyeun Kim Big Data Research Center Department of Computer Science and StatisticsJeju National UniversityKoreaJeju-si63243Korea Department of Computer Engineering(and Advanced Technology Research Institute) Jeju National UniversityJeju 63243Korea

In recent times,the evolution of blockchain technology has got huge attention from the research community due to its versatile applications and unique security *** IoT has shown wide adoption in various applications including smart cities,healthcare,trade,business,*** these applications,fitness applications have been widely considered for smart fitness *** users of the fitness system are increasing at a high rate thus the gym providers are constantly extending the fitness ***,scheduling such a huge number of requests for fitness exercise is a big ***,the user fitness data is critical thus securing the user fitness data from unauthorized access is also *** overcome these issues,this work proposed a blockchain-based load-balanced task scheduling approach.A thorough analysis has been performed to investigate the applications of IoT in the fitness industry and various scheduling *** proposed scheduling approach aims to schedule the requests of the fitness users in a load-balanced way that maximize the acceptance rate of the users’requests and improve resource *** performance of the proposed task scheduling approach is compared with the state-of-the-art approaches concerning the average resource utilization and task rejection *** obtained results confirm the efficiency of the proposed scheduling *** investigating the performance of the blockchain,various experiments are performed using the Hyperledger Caliper concerning latency,throughput,resource *** Solo approach has shown an improvement of 32%and 26%in throughput as compared to Raft and Solo-Raft approaches *** obtained results assert that the proposed architecture is applicable for resource-constrained IoT applications and is extensible for different IoT applications.

关键词： Load balancing resource scheduling task scheduling Internet of things blockchain fitness applications

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An Ensemble Learning Based Approach for Detecting and Tracking COVID19 Rumors

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Computers, Materials & Continua 2022年第1期70卷 1721-1747页

作者： Sultan Noman Qasem Mohammed Al-Sarem faisal Saeed Computer Science Department College of Computer and Information SciencesAl Imam Mohammad Ibn Saud Islamic University(IMSIU)Riyadh11432Saudi Arabia Computer Science Department Faculty of Applied ScienceTaiz UniversityTaiz6803Yemen College of Computer Science and Engineering Taibah UniversityMedinaSaudi Arabia Information System Department Saba’a Region UniversityMareebYemen

Rumors regarding epidemic diseases such as COVID 19,medicines and treatments,diagnostic methods and public emergencies can have harmful impacts on health and political,social and other aspects of people’s lives,especially during emergency situations and health *** huge amounts of content being posted to social media every second during these situations,it becomes very difficult to detect fake news(rumors)that poses threats to the stability and sustainability of the healthcare sector.A rumor is defined as a statement for which truthfulness has not been *** COVID 19,people found difficulty in obtaining the most truthful news easily because of the huge amount of unverified information on social *** methods have been applied for detecting rumors and tracking their sources for COVID 19-related ***,very few studies have been conducted for this purpose for the Arabic language,which has unique ***,this paper proposes a comprehensive approach which includes two phases:detection and *** the detection phase of the study carried out,several standalone and ensemble machine learning methods were applied on the Arcov-19 dataset.A new detection model was used which combined two models:The Genetic Algorithm Based Support Vector Machine(that works on users’and tweets’features)and the stacking ensemble method(that works on tweets’texts).In the tracking phase,several similarity-based techniques were used to obtain the top 1%of similar tweets to a target tweet/post,which helped to find the source of the *** experiments showed interesting results in terms of accuracy,precision,recall and f1-Score for rumor detection(the accuracy reached 92.63%),and showed interesting findings in the tracking phase,in terms of ROUGE L precision,recall and f1-Score for similarity techniques.

关键词： Rumor detection rumor tracking similarity techniques COVID-19 social media analytics

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Blockchain-Based Decentralized Authentication Model for IoT-Based E-Learning and Educational Environments

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Computers, Materials & Continua 2023年第5期75卷 3133-3158页

作者： Osama A.Khashan Sultan alamri Waleed Alomoush Mutasem K.Alsmadi Samer Atawneh Usama Mir Research and Innovation Centers Rabdan AcademyP.O.Box 114646Abu DhabiUnited Arab Emirates College of Computing and Informatics Saudi Electronic UniversityRiyadh13316Saudi Arabia School of Information Technology Skyline University CollegeP.O.Box 1797SharjahUnited Arab Emirates Department of MIS College of Applied Studies and Community ServicesImam Abdulrahman Bin Faisal UniversityP.O.Box 1982DammamSaudi Arabia Department of Computer Science University of WindsorWindsorN9J3Y1Canada

In recent times,technology has advanced significantly and is currently being integrated into educational environments to facilitate distance learning and interaction between *** the Internet of Things(IoT)into education can facilitate the teaching and learning process and expand the context in which students ***,learning data is very sensitive and must be protected when transmitted over the network or stored in data ***,the identity and the authenticity of interacting students,instructors,and staff need to be verified to mitigate the impact of ***,most of the current security and authentication schemes are centralized,relying on trusted third-party cloud servers,to facilitate continuous secure *** addition,most of these schemes are resourceintensive;thus,security and efficiency issues arise when heterogeneous and resource-limited IoT devices are being *** this paper,we propose a blockchain-based architecture that accurately identifies and authenticates learners and their IoT devices in a decentralized manner and prevents the unauthorized modification of stored learning records in a distributed university *** allows students and instructors to easily migrate to and join multiple universities within the network using their identity without the need for user *** proposed architecture was tested using a simulation tool,and measured to evaluate its *** simulation results demonstrate the ability of the proposed architecture to significantly increase the throughput of learning transactions(40%),reduce the communication overhead and response time(26%),improve authentication efficiency(27%),and reduce the IoT power consumption(35%)compared to the centralized authentication *** addition,the security analysis proves the effectiveness of the proposed architecture in resisting various attacks and ensuring the security requirements of learning data in the unive

关键词： Blockchain decentralized authentication Internet of Things(IoT) E-learning IoT security

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Six Minute Walk Test to assess functional capacity in chronic liver disease patients

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World Journal of Gastroenterology 2007年第29期13卷 3996-4001页

作者： Hatem f Alameri faisal M Sanai Manal Al Dukhayil Nahla A Azzam Khalid A Al-Swat Ahmad S Hersi Ayman A Abdo Unit of Pulmonary Medicine Department of Medicine King Saud University Riyadh Saudi Arabia Hepatology Division Department of Medicine Riyadh Military Hospital Riyadh Saudi Arabia Unit of Gastroenterology Department of Medicine King Saud University Riyadh Saudi Arabia

AIM: To examine the utility of Six Minute Walk Test (6MWT) in patients with chronic liver disease (CLD). METHODS: Two hundred and fifty subjects between the ages of 18 and 80 (mean 47) years performed 6MWT and the Six Minute Walk Distance (6MWD) was measured. RESULTS: The subjects were categorized into four groups. Group A (n = 45) healthy subjects (control); group B (n = 49) chronic hepatitis B patients; group C (n = 54) chronic hepatitis C patients; group D (n = 98) liver cirrhosis patients. The four groups differed in terms of 6MWDs (P fication was negatively correlated with the 6MWD in cirrhosis (group D) patients (r = -0.328, P f a 12 mo follow-up period, 15 of the 98 cirrhosis patients had died from disease complications. The 6MWD for the surviving cirrhotic patients was longer than for non-survivors (317 ± 101 vs 245 ± 145 m, P = 0.021; 95% CI 11-132). The 6MWD was found to be an independent predictor of survival (P = 0.024). CONCLUSION: 6MWT is a useful tool for assessing physical function in CLD patients. We suggest that 6MWD may serve as a prognostic indicator in patients with liver cirrhosis.

关键词： Six Minute Walk Test Chronic liver disease functional capacity

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Hybrid Renewable Energy Resources Management for Optimal Energy Operation in Nano-Grid

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Computers, Materials & Continua 2022年第5期71卷 2091-2105页

作者： faiza Qayyum faisal Jamil Shabir Ahmad Do-Hyeun Kim Department of Computer Engineering Jeju National UniversityJeju-siJeju Special Self-Governing Province63243Korea Department of IT Convergence Engineering Gachon UniversitySujeong-GuSeongnam-SiGyeonggi-Do461-701Korea

Renewable energy resources are deemed a potential energy production source due to their cost efficiency and harmless reaction to the environment,unlike non-renewable energy ***,they often fail to meet energy requirements in unfavorable weather *** concept of Hybrid renewable energy resources addresses this issue by integrating both renewable and non-renewable energy resources to meet the required energy *** this paper,an intelligent cost optimization algorithm is proposed to maximize the use of renewable energy resources and minimum utilization of non-renewable energy resources to meet the energy requirement for a nanogrid *** actual data set comprising information about the load and demand of utility grids is used to evaluate the performance of the proposed nanogrid energy management *** objective function is formulated to manage the nanogrid operation and implemented using a variant of Particle Swarm Optimization(PSO)named recurrent PSO(rPSO).firstly,rPSO algorithm minimizes the installation cost for ***,the proposed NEMS ensures cost efficiency for the post-installation period by providing a daily operational plan and optimizing renewable ***-of-the-art optimization models,including Genetic Algorithm(GA),bat and different Mathematical Programming Language(AMPL)solvers,are used to evaluate the *** study’s outcomes suggest that the proposed work significantly reduces the use of diesel generators and fosters the use of renewable energy resources and beneficiates the eco-friendly environment.

关键词： Smart grid nanogrid distributed generation(DG) renewable energy optimization machine learning

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Interrelationships between Deformation and Metamorphic Events across the Western Hinterland Zone, NW Pakistan

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Journal of Earth Science 2016年第4期27卷 584-598页

作者： Asghar Ali Mustafa Yar Muhammad Asif Khan Shah faisal Department of Geology University of Peshawar Department of Earth and Environmental Sciences Bahria University National Centre of Excellence in Geology University of Peshawar Earth and Environmental Sciences IKBAS University of British Columbia

Microscopic to mesoscopic structural investigations and foliation intersection axes（fIAs） preserved in porphyroblasts reveal a very complex history of deformation and tectonism within the southwestern part of the western hinterland zone along the northern margin of the Indian plate, NW Pakistan. D_1, D_2, and D_3 related structures in the southwestern part resemble the f_1/f_2, f_3, and f_4 related structures in the northeastern part of the western hinterland zone. These structures developed at the same time through the same changes in the direction of bulk shortening in southwestern and northeastern parts of the western hinterland zone. fIA set 1 indicates NW-SE shortening. The D_2 fabrics, mineral lineations and fold axes indicate E-W shortening. fIA set 2, D_3 fold axes and mineral lineations indicate NNE-SSW shortening. D_3 deformation event is equivalent to the f_4 deformation event in the northeastern part of the western hinterland zone. D_4 fold axes, mineral stretching lineations and axial plane foliation suggest ENE-WSW shortening. The D_4 NNW-SSE fabrics, which formed in the region after the formation of the MMT（main mantle thrust）, Khairabad-Panjal thrust fault, Hissartang thrust fault and MBT（main boundary thrust）, likely resulted from ENE-WSW bulk shortening related to development of the Hazara-Kashmir syntaxis.

关键词： fIA western hinterland zone microstructure mesostructure metamorphism tectonics,NW Pakistan.

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Internal friction behavior of Zr_(59)fe_(18)Al_(10)Ni_(10)Nb_(3)metallic glass under different aging temperatures

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Chinese Physics B 2021年第2期30卷 426-430页

作者： Israa faisal Ghazi Israa Meften Hashim Aravindhan Surendar Nalbiy Salikhovich Tuguz Aseel MAljeboree Ayad fAlkaim Nisith Geetha Department of Materials Engineering Engineering CollegeUniversity of Al-QadisiyahQadisiyyahIraq Nursing College University of Al-QadisiyahQadisiyyahIraq Department of Pharmacology Saveetha Dental College and HospitalSaveetha Institute of Medical and Technical SciencesChennaiIndia Department of Higher Mathematics Kuban State Agrarian UniversityKrasnodarRussian Federation College of Sciences for Women University of BabylonBabylonIraq Department of Electrical and Electronics Engineering Sengunthar College of EngineeringTiruchengodeIndia

We investigate the role of aging temperature on relaxation of internal friction in Zr_(59)fe_(18)Al_(10)Ni_(10)Nb_(3)metallic *** this purpose,dynamic mechanical analysis with different annealing temperatures and frequency values is *** results indicate that the aging process leads to decrease in the dissipated energy in the temperature range of glass *** is also found that the increase in applied frequency weakens the loss factor intensity in the metallic ***,the Kohlrausch-Williams-Watts(KWW)equation is used to evaluate the evolution of internal friction during the aging *** to the results,higher annealing temperature will make the primary internal friction in the material increase;however,a sharp decline is observed with the *** drop in characteristic time of internal friction is also closely correlated to the rate of atomic rearrangement under the dynamic excitation so that at higher annealing temperatures,the driving force for the collaborative movement of atoms is easily provided and the mean relaxation time significantly decreases.

关键词： metallic glass internal friction relaxation dynamic analysis

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Complex Problems Solution as a Service Based on Predictive Optimization and Tasks Orchestration in Smart Cities

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Computers, Materials & Continua 2021年第10期69卷 1271-1288页

作者： Shabir Ahmad Jehad Ali faisal Jamil Taeg Keun Whangbo DoHyeun Kim Department of IT Convergence Engineering Gachon UniversitySujeong-GuSeongnam-SiGyeonggi-Do461-701Korea Department of Computer Engineering and Department of AI Convergence NetworkAjou UniversitySuwonKorea Computer Engineering Department Jeju National UniversityJeju63243Korea

Smart cities have different contradicting goals having no apparent *** selection of the appropriate solution,which is considered the best compromise among the candidates,is known as complex *** city administrators face different problems of complex nature,such as optimal energy trading in microgrids and optimal comfort index in smart homes,to mention a *** paper proposes a novel architecture to offer complex problem solutions as a service(CPSaaS)based on predictive model optimization and optimal task orchestration to offer solutions to different problems in a smart *** model optimization uses a machine learning module and optimization objective to compute the given problem’s *** task orchestration module helps decompose the complex problem in small tasks and deploy them on real-world physical sensors and *** proposed architecture is hierarchical and modular,making it robust against faults and easy to *** proposed architecture’s evaluation results highlight its strengths in fault tolerance,accuracy,and processing speed.

关键词： Internet of things complex problem solving task modeling embedded IoT systems predictive optimization artificial cognition task orchestration

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Phytochemical Analysis,Estimation of Quercetin,and in Vitro Anti-Diabetic Potential of Stevia Leaves Samples Procured from Two Geographical Origins

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Phyton-International Journal of Experimental Botany 2022年第10期91卷 2349-2365页

作者： Kuntal Das Syed Mohammed Basheeruddin Asdaq M.Saifulla Khan Sravani Singirikonda Abdulhakeem S.alamri Walaa f.Alsanie Majid Alhomrani Sreeharsha Nagaraja Katharigatta N.Venugopala Department of Pharmacognosy and Phytochemistry Krupanidhi College of PharmacyVarthurHobliBengaluru560035India Department of Pharmacy Practice College of PharmacyAlMaarefa UniversityDariyahRiyadh13713Saudi Arabia Department of Clinical Laboratory Sciences The Faculty of Applied Medical SciencesTaif UniversityTaif21944Saudi Arabia Centre of Biomedical Sciences Research(CBSR) Deanship of Scientific ResearchTaif UniversityTaif21944Saudi Arabia Department of Pharmaceutical Sciences College of Clinical PharmacyKing Faisal UniversityAl-HofufAl-Ahsa31982Saudi Arabia Department of Pharmaceutics Vidya Siri College of PharmacyBangalore560035India Department of Biotechnology and food Science Faculty of Applied SciencesDurban University of TechnologyDurban4001South Africa

The current study used RP-HPLC to compare phytochemicals and estimate the bioactive constituents found in Stevia rebaudiana Bert.(SRB)leaves collected from two different geographical *** leaves were collected from Bangalore,Karnataka,India,and Reduit,*** were prepared using ethanol and aqueous sol*** analysis was used to evaluate moisture content,ash values,crude fibers,and extractive *** that,preliminary phytochemical screening was done on both ethanol leaves extracts,and subsequently total flavonoid content was *** addition,TLC chromatograms and RP-HPLC studies were performed on both plant extracts to determine the presence of flavonoid components in both leaves extracts,followed by in vitro anti-diabetic activity was performed with alpha amylase and alpha glucosidase enzymes against Acarbose as *** revealed that both the extracts from two different geographical sources varied significantly with the yield,content of chemicals,and presence of quercetin(flavonoid)content when estimated through the RP-HPLC standardized ***,flavonoids,proteins,steroids,saponins,terpenoids,and phenols were found in various concentrations during phytochemical *** both zones,the ethanol leaves extract of SRB taken from Mauritius had a greater content of phytochemicals and a higher yield than other extracts due to the soil *** Mauritius sample had greater total flavonoid levels as well as more quercetin(0.92±0.011)than the other *** that,ethanol extract inhibited enzymes(alpha amylase,alpha glucosidases)more than aqueous extract,and this inhibition was dose *** them,the Mauritius ethanol sample showed higher anti-diabetic efficacy than the Indian sample,but this difference was not ***,SRB ethanol leaves extracts outperformed other leaves extracts in terms of yield,phytoconstituents,and total flavo***,both SRB samples had high querce

关键词： Antidiabetic activity Stevia rebaudiana phytochemicals proximate analysis TLC RP-HPLC

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