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Structural, electronic, and optical studies of chalcogenides stannite Cu_(2)CdSnX_(4)(X=S, Se, and Te): insights from the DFT study

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Optoelectronics Letters 2025年第2期21卷 69-76页

作者： Jamal GUERROUM mohamed AL-HATTAB Lhoucine MOUDOU khalid RAHMANI Youssef LACHTIOUI Omar BAJJOU Laboratory of Engineering in Chemistry and Physics of Matter Faculty of Sciences and TechnicsSultan Moulay Slimane UniversityBeni Mellal BP 52323000Morocco Ecole Normale Supérieure Mohammed V University in RabatMorocco College of Graduate Studies University of South AfricaPretoriaSouth Africa

In this paper,we have calculated the structural,electronic,and optical properties of chalcogenide stannite Cu_(2)CdSnX4(X=S,Se,Te) *** calculations are based on the density functional theory (DFT) method and are performed using the Cambridge sequential total energy package (CASTEP) code included in the Biovia Material Studio 20 *** optical properties have been studied in a domain that extends energetically from 10 meV to 40 *** results show that Cu_(2)CdSnX4(X=S,Se,Te) stannite exhibits absorption in the visible region,the refractive index decreases with increasing energy,and the refractive index values are n=3.2,3.73 and 3.75 for Cu_(2)CdSnS_(4),Cu_(2)CdSnSe_(4)and Cu_(2)CdSnTe_(4),*** show also high conductivity,which implies that this material is promising for solar *** results argue in favor of the use of these materials in various potential *** density of state,band structures,and structural properties of Cu_(2)CdSnX4(X=S,Se,and Te) stannite are also studied in this work.

关键词： materials electronic refractive

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A new systematic firefly algorithm for forecasting the durability of reinforced recycled aggregate concrete

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Frontiers of Structural and Civil Engineering 2022年第3期16卷 329-346页

作者： Wafaa mohamed SHABAN khalid ELBAZ mohamed AMIN Ayat gamal ASHOUR Department of Civil and Environmental Engineering College of EngineeringShantou UniversityShantou 515063China Department of Civil Engineering Misr Higher Institute of Engineering and TechnologyMansouraEgypt Department of Civil Engineering Higher Future Institute of Engineering and TechnologyMansouraEgypt Guangdong Engineering Center for Structure Safety and Health Monitoring Shantou UniversityShantou 515063China Civil and Architectural Construction Department Faculty of Technology and EducationSuez UniversityIsmailiaEgypt Department of Civil and Environmental Engineering Collage of EngineeringUniversity of SharjahSharjah 27272UAE

This study presents a new systematic algorithm to optimize the durability of reinforced recycled aggregate *** proposed algorithm integrates machine learning with a new version of the firefly algorithm called chaotic based firefly algorithm(CFA)to evolve a rational and efficient predictive *** CFA optimizer is augmented with chaotic maps and Levy flight to improve the firefly performance in forecasting the chloride penetrability of strengthened recycled aggregate concrete(RAC).A comprehensive and credible database of distinctive chloride migration coefficient results is used to establish the developed algorithm.A dataset composite of nine effective parameters,including concrete components and fundamental characteristics of recycled aggregate(RA),is used as input to predict the migration coefficient of strengthened RAC as output,k-fold cross validation algorithm is utilized to validate the hybrid *** numerical benchmark analyses are applied to prove the superiority and applicability of the CFA algorithm in predicting chloride *** show that the developed CFA approach significantly outperforms the firefly algorithm on almost tested functions and demonstrates powerful *** addition,the proposed strategy can be an active tool to recognize the contradictions in the experimental results and can be especially beneficial for assessing the chloride resistance of RAC.

关键词： chloride penetrability recycled aggregate concrete machine learning concrete components durability

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Effects of rare-earth Pr3+-Dy3+ doping on structural,magnetic,optical and dielectric properties of Zn2Y hexaferrite

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Journal of Rare Earths 2025年第2期43卷 329-336页

作者： Ibrahim Mohammed mohamed E.El Sayed Ali Shawabkeh Mohammad N.Murshed Ibtehaj F.Alshdoukhi Zeinhom M.El-Bahy J.Mohammed A.K.Srivastava Department of Physics Lovely Professional University Department of Science Technology Waziri Umaru Federal Polytechnic Birnin Kebbi Physics Department Faculty of Science and ArtsKing Khalid University College of Engineering and Technology American University of the Middle East Department of Basic Sciences College of Science and Health ProfessionsKing Saud Bin Abdulaziz University for Health ScienceKing Abdullah International Medical Research Center Department of Chemistry Faculty of ScienceAl-Azhar University Department of Physics Faculty of ScienceFederal University Dutse

This study was conducted to investigate the properties of Pr3+-Dy3+doped Zn2Y-type hexaferrite for potential technological applications.X-ray diffraction（XRD）,Fourier transform infrared spectroscopy（FTIR） and field-emission scanning electron microscopy（FESEM） were used to analyze structural *** crystallite size in the synthesized samples varies between 57.54 and 68.57 *** vibrational bands at 400 and 600 cm-1,common to all hexaferrites,were confirmed through *** FESEM analysis reveals an agglomeration of magnetic grains and a decrease in the average grain size from 1.24 to1.06 μ*** M-H loops show that,with x values of 0.0,0.1,and 0.2,the saturation magnetization is determined to be 34.76,34.23,and 32.52 emu/g,*** corresponding coercivity values are21.24,30.39,and 33.99 ***-visible spectroscopy using Tauc theory reveals an increase in the optical band gap from 2.32 to 2.50 eV,indicating a tunable energy band structure by incorporating Pr3+-Dy3+*** dielectric constant increases,whereas AC conductivity decreases with increased Pr3+-Dy3+*** obtained results suggest the potential suitability of these materials for various technological applications.

关键词： Dielectric constant Magnetic hysteresis Optical band gap Pr3+-Dy3+ Rare earths Zn2Y-type hexaferrite

Gaining-Sharing Knowledge Based Algorithm for Solving Stochastic Programming Problems

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Computers, Materials & Continua 2022年第5期71卷 2847-2868页

作者： Prachi Agrawal khalid Alnowibet Ali Wagdy mohamed Yogananda School of Artificial Intelligence Computers&Data ScienceShoolini UniversitySolan173229India Statistics and Operations Research Department College of ScienceKing Saud UniversityRiyadh11451Kingdom of Saudi Arabia Operations Research Department Faculty of Graduate Studies for Statistical ResearchCairo UniversityGiza12613Egypt Department of Mathematics and Actuarial Science School of Science and EngineeringThe American University in CairoEgypt

This paper presents a novel application of metaheuristic algorithmsfor solving stochastic programming problems using a recently developed gaining sharing knowledge based optimization (GSK) algorithm. The algorithmis based on human behavior in which people gain and share their knowledgewith others. Different types of stochastic fractional programming problemsare considered in this study. The augmented Lagrangian method (ALM)is used to handle these constrained optimization problems by convertingthem into unconstrained optimization problems. Three examples from theliterature are considered and transformed into their deterministic form usingthe chance-constrained technique. The transformed problems are solved usingGSK algorithm and the results are compared with eight other state-of-the-artmetaheuristic algorithms. The obtained results are also compared with theoptimal global solution and the results quoted in the literature. To investigatethe performance of the GSK algorithm on a real-world problem, a solidstochastic fixed charge transportation problem is examined, in which theparameters of the problem are considered as random variables. The obtainedresults show that the GSK algorithm outperforms other algorithms in termsof convergence, robustness, computational time, and quality of obtainedsolutions.

关键词： Gaining-sharing knowledge based algorithm metaheuristic algorithms stochastic programming stochastic transportation problem

Digital Watermarking Scheme for Securing Textual Database Using Histogram Shifting Model

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Computers, Materials & Continua 2022年第6期71卷 5253-5270页

作者： khalid A.El Drandaly Walid Khedr Islam S.mohamed Ayman mohamed Mostafa Faculty of Computers and Informatics Zagazig UniversityZagazig44519Egypt College of Computer and Information Sciences Jouf UniversitySakaka72314Saudi Arabia

Information security is one of the most important methods of protecting the confidentiality and privacy of internet *** greater the volume of data,the more the need to increase the security methods for protecting data from *** task can be challenging for researchers in terms of managing enormous data and maintaining their safety and *** of digital content is a major issue in maintaining the privacy and secrecy of *** this end,digital watermarking is based on the concept of information security through the insertion and detection of an embedded watermark in an efficient *** methodologies in the research on digital watermarking result in data distortion after embedding the *** scenario can reduce the efficiency of detecting watermarks as well as violate data *** study adapts a robust reversible histogram shifting(HS)technique for textual data in relational ***,the study presents a digital watermarking scheme intended for document copyright protection and proof of *** major advantage of the proposed watermarking scheme is that it can protect digital data and preserve data *** the best of our knowledge,this research methodology is promising for use in the HS expansion model for watermarking data on nonnumeric *** addition,the results showed that despite exposing the database to an insertion attacks at 50%and 75%of the watermark,the proposed algorithm can recovermore than half of the embedded watermark in all addition and alteration attacks *** a result,the watermark information can be retained and restored completely.

关键词： Information security digital watermarking information hiding histogram shifting technique

Evaluation of the prevalence and risk factors of burnout syndrome among healthcare workers:A cross-sectional study

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World Journal of Psychiatry 2025年第2期15卷 118-129页

作者： Nur adam mohamed Yusuf Abdirisak mohamed Rahma Yusuf Haji Mohamud Adan Ali Gabow Department of Psychiatry and Behavioral Sciences Mogadishu Somali-Turkiye Recep Tayyip Erdogan Training and Research HospitalMogadishu 2526Somalia Faculty of Medicine and Surgery Somali National UniversityMogadishu 2526Somalia Department of Nursing Mogadishu Somali-Turkiye Recep Tayyip Erdogan Training and Research HospitalMogadishu 2526Somalia

BACKGROUND Burnout syndrome is a significant issue among healthcare professionals worldwide,marked by depersonalization,emotional exhaustion,and a reduced sense of personal *** psychological and physical burden profoundly affects healthcare professionals'quality of care and overall *** Somalia,where the healthcare system faces numerous challenges,the escalating demand for medical services and inadequate resources,coupled with overwhelming workloads,long hours,and high-stress levels,make healthcare providers particularly vulnerable to burnout ***,in turn,affects both the mental health of healthcare personnel and the quality of care they *** To examine the prevalence and determinants of burnout syndrome among healthcare practitioners in Mogadishu,*** This cross-sectional prospective study was performed among 246 healthcare providers employed at a tertiary care hospital in Mogadishu,Somalia,who were recruited via random *** were collected using questionnaires that covered sociodemographic,psychological,work-related characteristics,and burnout *** and multivariate logistic regression analyses were performed to identify the variables that correlated with burnout *** results were presented using adjusted odds ratios(AORs),95%CIs,and P values,with a cutoff of 0.05 for identifying significant *** Among the participants,24%(95%CI:18.8%–29.8%)exhibited symptoms of burnout *** associated with burnout included female gender(AOR=6.60;95%CI:2.29-19.04),being married(AOR=3.07;95%CI:1.14-8.28),being divorced or widowed(AOR=5.84;95%CI:1.35-25.35),working more than 7 night shifts(AOR=3.19;95%CI:1.30–7.82),having less than 5 years of job experience(AOR=5.28;95%CI:1.29-21.65),experiencing poor sleep quality(AOR=5.29;95%CI:1.88-14.89),and exhibiting depressive(AOR=4.46;95%CI:1.59-12.53)and anxiety symptoms(AOR=7.34;95%CI:2.49-21.60).CONCLUSION This study found that nearly

关键词： Burnout syndrome Risk factors Healthcare workers Mogadishu Somalia

Hydrometallurgy two stage process for preparation of (Nd,La,Ce)_(2)O_(3) from end-of-life NiMH batteries

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Journal of Rare Earths 2024年第2期42卷 415-423,I0007页

作者： Karim Tanji khalid Ouzaouit mohamed Belghiti Isam Lamsayety Hakim Faqir Intissar Benzakour Centre de recherche REMINEX-Groupe MANAGEM MarrakechMorocco

The present work aims to investigate the recovery of light rare earth elements(LREEs) oxides from end-oflife NiMH batteries using a hydro metallurgical process followed by effective *** operational leaching parameters such as phosphoric acid concentration,temperature,and the solid-liquid ratio were first optimized by Box-Behnken *** results reveal that under optimum conditions([H_(3)PO_(4)]=2 mol/L,T=80℃,and S/L=1:10 g/mL) the leaching efficiencies of Ni,Co reach 98.1% and99.3%.While La,Ce,and Nd elements remain in the leaching residue as(La,Ce,Nd)PO_(4) with yields of 98.2%,98.6%,and 99.6% for La,Ce,and Nd,***,the(La,Ce,Nd)PO_(4) is leached with HCl acid,then the rare earth oxalate was precipitated using oxalic acid at a pH of 1.8 and then the product was calcined at 800℃ for 2 h in order to synthesize the(Nd,La,Ce)_(2)O_(3).The analysis using scanning electron microscopy(SEM) coupled with energy dispersive X-ray spectroscopy(EDX) confirms the homogeneity of(Nd,La,Ce)_(2)O_(3) particles that have two morphologies,i.e.,flower and sticks with a particle size between 3and 6 μ*** unit cell parameters of(Nd,La,Ce)_(2)O_(3) were calculated after Rietveld refinement of the XRD patterns,in the space group of Fm-3m are a=b=c=0.57921 nm and the volume equal to 0.194322 nm^(3).

关键词： NiMH batteries Hydrometallurgical process Leaching Phosphoric acid Box-Behnken Light rare earth oxides

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Managing Delivery of Safeguarding Substances as a Mitigation Against Outbreaks of Pandemics

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Computers, Materials & Continua 2021年第7期68卷 1161-1181页

作者： Said Ali Hassan khalid Alnowibet Prachi Agrawal Ali Wagdy mohamed Department of Operations Research and Decision Support Faculty of Computers and Articial IntelligenceCairo UniversityGiza12613Egypt Department of Statistics and Operations Research College of ScienceKing Saud UniversityRiyadhSaudi Arabia Trafc Safety Technologies Chair Vice Deanship of Scientic ResearchKing Saud UniversityRiyadhSaudi Arabia Department of Mathematics and Scientic Computing National Institute of TechnologyHamirpur177005India Operations Research Department Faculty of Graduate Studies for Statistical ResearchCairo UniversityGiza12613Egypt School of Engineering and Applied Sciences Wireless Intelligent Networks Center(WINC)Nile UniversityGizaEgypt

The optimum delivery of safeguarding substances is a major part of supply chain management and a crucial issue in the mitigation against the outbreak of pandemics.A problem arises for a decision maker who wants to optimally choose a subset of candidate consumers to maximize the distributed quantities of the needed safeguarding substances within a specic time period.A nonlinear binary mathematical programming model for the problem is *** decision variables are binary ones that represent whether to choose a specic consumer,and design constraints are formulated to keep track of the chosen *** better illustrate the problem,objective,and problem constraints,a real application case study is *** case study involves the optimum delivery of safeguarding substances to several hospitals in the Al-Gharbia Governorate in *** hospitals are selected to represent the consumers of safeguarding substances,as they are the rst crucial frontline for mitigation against a pandemic outbreak.A distribution truck is used to distribute the substances from the main store to the hospitals in specied required quantities during a given working *** objective function is formulated in order to maximize the total amount of delivered quantities during the specied time *** case study is solved using a novel Discrete Binary Gaining Sharing Knowledge-based Optimization algorithm(DBGSK),which involves two main stages:discrete binary junior and senior gaining and sharing *** has the ability of nding the solutions of the introduced problem,and the obtained results demonstrate robustness and convergence toward the optimal solutions.

关键词： Safeguarding substances mitigation against pandemic outbreaks supply chain management metaheuristic optimization

Optimum Location of Field Hospitals for COVID-19: A Nonlinear Binary Metaheuristic Algorithm

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Computers, Materials & Continua 2021年第7期68卷 1183-1202页

作者： Said Ali Hassan khalid Alnowibet Prachi Agrawal Ali Wagdy mohamed Department of Operations Research and Decision Support Faculty of Computers and Artificial IntelligenceCairo UniversityGiza12613Egypt College of Science Department of Statistics and Operations ResearchKing Saud UniversityRiyadhSaudi Arabia Department of Mathematics and Scientific Computing National Institute of Technology HamirpurHimachal Pradesh177005India Department of Operations Research Faculty of Graduate Studies for Statistical ResearchCairo UniversityGiza12613Egypt Wireless Intelligent Networks Center(WINC) School of Engineering and Applied SciencesNile UniversityGizaEgypt

Determining the optimum location of facilities is critical in many fields,particularly in *** study proposes the application of a suitable location model for field hospitals during the novel coronavirus 2019(COVID-19)*** used model is the most appropriate among the three most common location models utilized to solve healthcare problems(the set covering model,the maximal covering model,and the P-median model).The proposed nonlinear binary constrained model is a slight modification of the maximal covering model with a set of nonlinear *** model is used to determine the optimum location of field hospitals for COVID-19 risk *** designed mathematical model and the solution method are used to deploy field hospitals in eight governorates in Upper *** this case study,a discrete binary gaining–sharing knowledge-based optimization(DBGSK)algorithm is *** DBGSK algorithm is based on how humans acquire and share knowledge throughout their *** DBGSK algorithm mainly depends on two junior and senior binary *** two stages enable DBGSK to explore and exploit the search space efficiently and effectively,and thus it can solve problems in binary space.

关键词： Facility location nonlinear binary model field hospitals for COVID-19 gaining-sharing knowledge-based metaheuristic algorithm