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Depression, Anxiety, Stress and Their Association with the Use of Electronic Devices among Adolescents during the COVID-19 Pandemic

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International Journal of Mental Health Promotion 2022年第2期24卷 251-262页

作者： Ahmad y.Alqassim Mohamed S.Mahfouz Mohammed M.Hakami Abdullah A.Al Faqih Ahmad A.Shugairi Malek R.Alsanosy ahmed y.rayyani AbdulAziz y.Albrraq Mohammed A.Muaddi Abdullah A.Alharbi Family and Community Medicine Department Faculty of MedicineJazan UniversityJazanSaudi Arabia

Background:Adolescence is a critical,multifactorial developmental *** the current pandemic of COVID-19,excessive using of electronic devices is a public health *** aim of this study is to investigate the relation-ship between depression and the use of electronic devices among secondary school children in Jazan,Saudi Arabia during the COVID-19 *** and Methods:The study is an observational,cross-sectional *** was collected using an anonymous online survey *** the Depression Anxiety Stress ***:A total of 427 participants were included in the *** prevalence of depression,anxiety,and stress in our study was 14.55%,12.01%,and 15.55%,*** the hours spent on electronic devices,13.6%of participants spent 1–4 h,43.6%spent 5–9 h,and 42.9%spent 10 h or more.86.7%reported an increase in their use of electronic devices during *** regression analysis revealed that the increase of Videogame Addiction Scale for Chil-dren is signiﬁcantly associated with an increase in Depression,Anxiety,and Stress scores(p-valuey found a positive correlation between electronic device use and increased prevalence of mental health *** also found signiﬁcantly increased use of electronic device during the COVID-19 lockdown;hence,more mental issues were *** is obvious that electronic device use needs to be more controlled among *** can be achieved by involving those who are in this age group in other activities,like sports,which can reduce the time they spend on electronic device.

关键词： COVID-19 depression electronic devices adolescents public health environmental health

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Impacts of environmental factors on urban heating

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Journal of Environmental Sciences 2010年第12期22卷 1903-1909页

作者： Rizwan ahmed Memon Dennis y.C.Leung Department of Mechanical Engineering Mehran University of Engineering & Technology Department of Mechanical Engineering The University of Hong Kong School of Energy and Environment City University of Hong Kong

This study investigated the impact of important environmental variables （i.e., wind speed, solar radiation and cloud cover） on urban heating. Meteorological parameters for fifteen years （from 1990 to 2005）, collected at a well developed and densely populated commercial area （Tsim Sha Tsui, Hong Kong）, were analyzed in details. Urban heat island intensity （UHII）, a well known indicator of urban heating, has been determined as the spatially averaged air-temperature difference between Tsim Sha Tsui and Ta Kwu Ling （a thinly populated rural area with lush vegetation）. Results showed that the UHII and cloud cover have increased by around 9.3% and 4%, respectively, whereas the wind speed and solar radiation have decreased by around 24% and 8.5%, respectively. The month of December experienced the highest UHII （10.2℃） but the lowest wind speed （2.6 m/sec） and cloud cover （3.8 oktas）. Conversely, the month of April observed the highest increases in the UHII （over 100%） and the highest decreases in wind speed （over 40 %） over fifteen years. Notably, the increases in the UHII and reductions in the wind speed were the highest during the night-time and early morning. Conversely, the intensity of solar radiation reduced while the intensity of urban cool island （UCII） increased during solar noon-time. Results demonstrated strong negative correlation between the UHII and wind speed （coefficient of determination, R^2 = 0.8） but no negative correlation between UCII and solar radiation attenuation. A possible negative correlation between UHII and cloud cover was investigated but could not be substantiated.

关键词： urban heat island urban cool island wind speed cloud cover

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Nonlinear numerical simulation of punching shear behavior of reinforced concrete flat slabs with shear-heads

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Frontiers of Structural and Civil Engineering 2020年第2期14卷 331-356页

作者： Dan VBOMPA ahmed yELGHAZOULI Department of Civil and Environmental Engineering Imperial College LondonLondon SIV72AZUK

This paper examines the structural response of reinforced concrete flat slabs,provided with flillyembedded shear-heads,through detailed three-dimensional nonlinear numerical simulations and parametric assessments using concrete damage plasticity *** of the adopted nonlinear finite element procedures are carried out against experimental results from three test *** gaining confidence in the ability of the numerical models to predict closely the full inelastic response and failure modes,numerical investigations are carried out in order to examine the influence of key material and geometric *** results of these numerical assessments enable the identification of three modes of failure as a function of the interaction between the shear-head and surrounding *** on the findings,coupled with results from previous studies,analytical models are proposed for predicting the rotational response as well as the ultimate strength of such slab *** recommendations are also provided for the design of shear-heads in RC slabs,including the embedment length and section *** analytical expressions proposed in this paper,based on a wide-ranging parametric assessment,are shown to offer a more reliable design approach in comparison with existing methods for all types of shear-heads,and are suitable for direct practical application.

关键词： non-linear numerical modelling concrete damage plasticity RC flat slabs shear-heads punching shear

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Exponential Attractor for a Nonlinear Boussinesq Equation

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Acta Mathematicae Applicatae Sinica 2006年第3期22卷 443-450页

作者： ahmed y. Abdallah Departmcnt of Mathematics University of Jordan Amman 11942 Jordan

This paper is devoted to prove the existence of an exponential attractor for the semiflow generated by a nonlinear Boussinesq equation. We formulate the Boussinesq equation as an abstract equation in the Hilbert space H0^2（0, 1） × L^2（0, 1）. The main step in this research is to show that there exists an absorbing set for the solution semiflow in the Hilbert space H0^3（0, 1） × H0^1（0, 1）.

关键词： Boussinesq equation absorbing set exponential attractor

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Task Scheduling Optimization in Cloud Computing Based on Genetic Algorithms

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Computers, Materials & Continua 2021年第12期69卷 3289-3301页

作者： ahmed y.Hamed Monagi H.Alkinani Faculty of Computers and Information Department of Computer ScienceSohag UniversitySohag82524Egypt Department of Computer Science and Artificial Intelligence College of Computer Science and EngineeringUniversity of JeddahJeddah21959Saudi Arabia

Task scheduling is the main problem in cloud computing that reduces system performance;it is an important way to arrange user needs and perform multiple *** computing is the most popular technology nowadays and has many research potential in various areas like resource allocation,task scheduling,security,privacy,*** improve system performance,an efficient task-scheduling algorithm is *** task-scheduling algorithms focus on task-resource requirements,CPU memory,execution time,and execution *** this paper,a task scheduling algorithm based on a Genetic Algorithm(GA)has been presented for assigning and executing different *** proposed algorithm aims to minimize both the completion time and execution cost of tasks and maximize resource *** evaluate our algorithm’s performance by applying it to two examples with a different number of tasks and *** first example contains ten tasks and four processors;the computation costs are generated *** last example has eight processors,and the number of tasks ranges from twenty to seventy;the computation cost of each task on different processors is generated *** achieved results show that the proposed approach significantly succeeded in finding the optimal solutions for the three objectives;completion time,execution cost,and resource utilization.

关键词： Cloud computing task scheduling genetic algorithm optimization algorithm

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Voltage imbalance mitigation in an active distribution network using decentralized current control

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Protection and Control of Modern Power Systems 2023年第2期8卷 68-84页

作者： ahmed M.M.Nour ahmed A.Helal Magdi M.El-Saadawi ahmed y.Hatata Alexandria Higher Institute of Engineering and Technology(AIET) AlexandriaEgypt Department of Electrical and Control Engineering Arab Academy for Science and Technology and Maritime TransportAlexandriaEgypt Department of Electrical Engineering Faculty of EngineeringMansoura UniversityMansouraEgypt Department of Electrical Engineering College of EngineeringShaqra UniversityShaqraKingdom of Saudi Arabia

Voltage imbalance(VI)is caused by the difference in connected single-phase load or generation in a low voltage distribution network(DN).VI increase in a smart distribution grid is due to the current practice of increasing single-phase distributed generators such as photovoltaic(PV)*** paper proposes a decentralized control method to mitigate VI using distributed batteries included in smart grid interfaced residential PV *** mitigate VI using the batteries in this way,five challenges must be overcome,i.e.,equalizing all battery stress currents within the DN,mitigating VI in abnormal conditions such as signal loss among bus controllers,being immune from the distorted feedback measurements,minimizing the steady-state error at different loads,and overcoming the insufficient number or capacity of the distributed batteries at the same *** fuzzy logic controllers(FLC)are proposed at each bus to overcome these five tasks based on a decentralized control *** proposed decentralized control based on FLC is compared with centralized control based on a PI *** proposed control method is tested and verified using simulations in the MATLAB/Simulink software,and the results validate the ability of the scheme to alleviate VI on a smart distribution network under both normal and abnormal conditions.

关键词： Fuzzy controller Distributed batteries Decentralized control Voltage imbalance Distributed PV

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A review on the generation, determination and mitigation of Urban Heat Island

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Journal of Environmental Sciences 2008年第1期20卷 120-128页

作者： RIZWAN ahmed Memon DENNIS y.C. Leung LIU Chunho Department of Mechanical Engineering the University of Hong Kong Hong Kong China.

Urban Heat Island （UHI） is considered as one of the major problems in the 21st century posed to human beings as a result of urbanization and industrialization of human civilization. The large amount of heat generated from urban structures, as they consume and re-radiate solar radiations, and from the anthropogenic heat sources are the main causes of UHI. The two heat sources increase the temperatures of an urban area as compared to its surroundings, which is known as Urban Heat Island Intensity （UHII）. The problem is even worse in cities or metropolises with large population and extensive economic activities. The estimated three billion people living in the urban areas in the world are directly exposed to the problem, which will be increased significantly in the near future. Due to the severity of the problem, vast research effort has been dedicated and a wide range of literature is available for the subject. The literature available in this area includes the latest research approaches, concepts, methodologies, latest investigation tools and mitigation measures. This study was carded out to review and summarize this research area through an investigation of the most important feature of UHI. It was concluded that the heat re-radiated by the urban structures plays the most important role which should be investigated in details to study urban heating especially the UHI. It was also concluded that the future research should be focused on design and planning parameters for reducing the effects of urban heat island and ultimately living in a better environment.

关键词： urban heat island (UHI) urbanization temperature rise mitigation

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Double-antibody-based nano-biosensing systemfor the onsite monitoring of SARS-CoV-2 variants

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Microsystems & Nanoengineering 2023年第4期9卷 247-262页

作者： Heba A.Hussein ahmed Kandeil Mokhtar Gomaa Rabeay y.A.Hassan Virology Department Animal Health Research Institute(AHRI)Agricultural Research Center(ARC)Giza 12619Egypt Biosensors Research Laboratory Zewail City of Science and Technology6th October CityGiza 12578Egypt Center of Scientific Excellence for Influenza Viruses Environmental Research DivisionNational Research CentreGiza 12622Egypt Nanoscience Program University of Science and Technology(UST)Zewail City of Science and TechnologyGiza 12578Egypt

The fast and reliable diagnosis of COVID-19 is the foremost priority for promoting public health ***, double-antibody-based immunobiosensor chips were designed, constructed, and exploited for clinicaldiagnosis. Gold nanoparticles/tungsten oxide/carbon nanotubes (AuNPs/WO3/CNTs) were used as the active workingsensor surface to support the chemical immobilization of a mixture of SARS-CoV-2 antibodies (anti-RBD-S and anti-RBD-S-anti-Llama monoclonal antibodies). The morphology and chemical functionalization of the fabricateddisposable immunochips was characterized using scanning electron microscopy (SEM), Fourier transform infrared(FTIR) spectroscopy, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). After full assayoptimization, the immunobiosensor showed a high sensitivity to detect SARS-CoV-2-S protein with limits of detectionand quantification of 1.8 and 5.6 pg/mL, respectively. On the other hand, for the SARS-CoV-2 whole virus particleanalysis, the detection and quantification limits were determined to be 5.7 and 17 pg/mL, respectively. The biosensorshowed a highly selective response toward SARS-CoV-2, even in the presence of influenza, nontargeting humancoronaviruses, and Middle East respiratory syndrome coronavirus (MERS-CoV). The immunochips exhibited distinctresponses toward the variants of concern: B.1>C.36.3>Omicron> Delta> Alpha coronavirus variants. For biosensorvalidation, twenty-nine clinical specimens were analyzed, and the impedimetric responses were positively detected fortwo Delta samples, eighteen Omicron samples, and six B.1-type samples in addition to three negative ***, the immunobiosensor was fabricated in the form of ready-to-use chips capable of sensitive detection ofvirus variants, especially variants of concern (VOC) and interest, in a specimen within 15 min. The chips providedinstantaneous detection with the direct application of clinical samples and are considered a point-of-care

关键词： system limits optimization

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New application of microbial fuel cell-based biosensor for monitoring the quality of actual potato chips’processing wastewater

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Waste Disposal and Sustainable Energy 2019年第3期1卷 227-235页

作者： ahmed y.Radeef Zainab Z.Ismail Department of Environmental Engineering University of BaghdadBaghdadIraq

In this study,a dual-chamber microbial fuel cell(MFC)fed with actual potato chips’processing wastewater(PCPW)was tested as a *** performance of MFC-based biosensor was evaluated in terms of the current measurement range,toxicity detection and sensitivity,and the operational *** results revealed that the MFC can simply be converted to an online biosensor unit to detect the harmful effect of suspended solids and acidic content in the actual PCPW on the anodic attached biofilm and the values of the generated current as well.A notable decrease in the current values was observed indicating the adverse effects of the harmful matters in the PCPW fed to the biosensor *** results proposed a competition between the harmful components and the favorable substrate in binding to the redox *** excellent fitting was obtained between the experimental and predicted results by I_(Km) model with determination coefficient(R^(2))and mean-square-error values of 0.927 and 0.363,***,a new approach was developed based on direct measurement of actual field data to replace the conventional statistical methods.

关键词： Microbial fuel cell Biosensor Modeling Potato chips processing wastewater Biodegradation

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Production of porous silica by the combustion of rice husk ash for tundish lining

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Journal of University of Science and Technology Beijing 2008年第3期15卷 307-313页

作者： y.M.Z.ahmed E.M.Ewais Z.I.Zaki Central Metallurgical Research and Development Institute(CMRDI)

In order to study the production of porous silica compacts by the combustion of rice husk ash （RHA） for tundish lining, the experimental design technique was used to evaluate the effect of firing temperature, soaking time and compaction pressure on controlling both the porosity degree and compressive strength of rice husk ash compacts. The results revealed that while the porosity degree of the compacts decreased with the increase in the entire studied parameters, the compressive strength exhibited another trend especially at a lower soaking time. At a lower soaking time, the increase in firing temperature led to a slight decrease in compressive strength and then increasing thereafter. The porous silica compacts having 30% porosity and 〉 2.5 MPa compressive strength suitable for tundish lining could be obtained from the combustion of rice husk ash compacts.

关键词： porous silica rice husk ash tundish lining compressive strength porosity

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