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Enhancement of Electric Conductivity in Transparent Glasse—Ceramic Nanocomposites of Bi_2O_3—BaTiO_3 Glasses

Journal of Materials Science & Technology 2013年第12期29卷 1166-1176页

作者： A.A.Bahgat M.G.Moustafa E.E.Shaisha Department of Physics Faculty of ScienceAl-Azhar University

The frequency and temperature dependent electrical conductivity measurements for heat-treated binary glass system with composition of （lO0-x）Bi203-xBaTi03 （x = 20, 30, 40 and 50, in mol%） were carried out. The glass was prepared by melt quenching technique and their corresponding glass-ceramic nanocomposites were obtained by suitable heat treatment. Nanostructured behavior and electrical properties of these glasses and their corresponding glass-ceramic nanocomposites were studied. X-ray diffraction （XRD） and differential scanning calorimetry confirmed the amorphous nature of the glasses. Moreover, XRD patterns of the samples indicate nanocrystallites embedded in the glass matrix. The Fourier transform infrared spectroscopy （FT-IR） spectral analysis showed that the band positions of glass system are within the wave number range of Bi06, Bi03 and Ti06 structural units. It is observed that the electrical conductivity is enhanced by 102-103 times in the transparent glass-ceramic nanocomposite phase. With further heat treatment, the conductivity decreased considerably in the stage of glass-ceramic nanocomposite phase as compared with the glassy phase sample. Therefore, partially devitrified phase is more suitable as cathode material in secondary batteries compared to its vitreous or fully crystalline counterpart. The conduction mechanism was confirmed to obey the adiabatic small polaron hopping （SPH）. AC conductivity measurements were performed as a function of temperature and frequency, showing a very slow increasing rate at low temperatures and then a fast rate at higher temperatures.

关键词： Barium titanat Transparent glass--ceramic nanocomposites DC electrical conductivity AC electrical conductivity Smallpolaron hopping

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A Model Transformation Approach for Detecting Distancing Violations in Weighted Graphs

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Computer Systems Science & Engineering 2021年第1期36卷 13-39页

作者： Ahmad F.Subahi Department of Computer Science University College of Al JamoumUmm Al Qura UniversityMakkah21421Saudi Arabia

This work presents the design of an Internet of Things(IoT)edge-based system based on model transformation and complete weighted graph to detect violations of social distancing measures in indoor public *** sensor network based on Bluetooth Low Energy is introduced as the infrastructure of the proposed design.A hybrid model transformation strategy for generating a graph database to represent groups of people is presented as a core middleware layer of the detecting system’s proposed architectural design.A Neo4j graph database is used as a target implementation generated from the proposed transformational system to store all captured real-time IoT data about the distances between individuals in an indoor area and answer user predefined queries,expressed using Neo4j Cypher,to provide insights from the stored data for decision *** proof of concept,a discrete-time simulation model was adopted for the design of a COVID-19 physical distancing measures case study to evaluate the introduced system ***-one weighted graphs were generated randomly and the degrees of violation of distancing measures were *** experimental results demonstrate the capability of the proposed system design to detect violations of COVID-19 physical distancing measures within an enclosed area.

关键词： Model-driven engineering(MDE) Internet-of-Things(IoTs) model transformation edge computing system design Neo4j graph databases

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Interdependence of friction, wear, and noise: A review

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Friction 2021年第6期9卷 1319-1345页

作者： Kevin LONTIN Muhammad KHAN Cranfield university MK430ALUK

Phenomena of friction,wear,and noise in mechanical contacts are particularly important in the field of tribomechanics but equally complex if one wants to represent their exact relationship with mathematical *** have been made to describe these phenomena with different approaches in *** efforts have been compiled in different reviews but most of them treated friction,wear mechanics,and acoustic noise ***,an in-depth review that provides a critical analysis on their interdependencies is still *** this review paper,the interdependencies of friction,wear,and noise are analysed in the mechanical contacts at asperitical *** origin of frictional noise,its dependencies on contact’s mechanical properties,and its performance under different wear conditions are critically reviewed.A discussion on the existing mathematical models of friction and wear is also provided in the last section that leads to uncover the gap in the existing *** review concludes that still a comprehensive analytical modelling approach is required to relate the interdependencies of friction,noise,and wear with mathematical expressions.

关键词： noise acoustic emission wear friction

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Assessment of water resources in Yarmouk River Basin using geospatial technique during the period 1980–2020

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Journal of Arid Land 2022年第2期14卷 154-166页

作者： Noor M al-KHARABSHEH Department of Water Resources and Environmental Management Al-Balqa Applied UniversityAl-Salt 19117Jordan

It is common knowledge that Yarmouk River Basin(YRB)is shared between Jordan and *** of YRB trans-boundary water resources is attracting increasing interest because it is a strategic water resource for the riparian ***,lack of sharing information regarding hydrological flows and basin’s water management between partners’countries makes it difficult to distinguish between natural and man-made factors affecting the water ***,this study seeks to address and assess the main on-site changes that exert on *** technique and arithmetic equations were combined to carry out an assessment of the changes on water resources in ***,information and field measurements of the basin were aggregated,compiled and presented to determine the extent of changes during the period *** findings showed that precipitation amount in the basin significantly declined during the period 1980-2020 in particularly after the year *** rate of groundwater was 550 x 103 m3/a,exceeding the basin’s safe *** down of static groundwater level over time approached the value of-3.2 m/a due to the over abstraction in the aquifer ***,the evaporation rate reached more than 99%in some regions in the ***,the number of private wells has increased from 98 wells in 1980 to 126 wells in 2020,showing the excessive extraction of *** findings indicate that the study area is subjected to a considerable groundwater depletion in the near future due to extensive abstraction,continuous drilling of illegal wells and decreased annual precipitation under the shadow of the rapid population growth and continuous influx of ***,decision makers-informed scenarios are suggested in the development of water resource portfolios,which involves the combination of management and infrastructural actions that enhance the water productivity of the *** studies are recommended to evaluate the on-sit

关键词： assessment geospatial technique on-site changes water resources Yarmouk River Basin

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Fuzzy Logic Inference System for Managing Intensive Care Unit Resources Based on Knowledge Graph

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Computers, Materials & Continua 2023年第12期77卷 3801-3816页

作者： Ahmad F Subahi Areej Athama Department of Computer Science University College of Al JamoumUmm Al-Qura UniversityMakkah21421Saudi Arabia

With the rapid growth in the availability of digital health-related data,there is a great demand for the utilization of intelligent information systems within the healthcare *** systems can manage and manipulate this massive amount of health-related data and encourage different decision-making *** can also provide various sustainable health services such as medical error reduction,diagnosis acceleration,and clinical services quality *** intensive care unit(ICU)is one of the most important hospital ***,there are limited rooms and resources in most *** times of seasonal diseases and pandemics,ICUs face high admission *** line with this increasing number of admissions,determining health risk levels has become an essential and imperative *** creates a heightened demand for the implementation of an expert decision support system,enabling doctors to accurately and swiftly determine the risk level of ***,this study proposes a fuzzy logic inference system built on domain-specific knowledge graphs,as a proof-of-concept,for tackling this healthcare-related *** system employs a combination of two sets of fuzzy input parameters to classify health risk levels of new admissions to *** proposed system implemented utilizes MATLAB Fuzzy Logic Toolbox via several experiments showing the validity of the proposed system.

关键词： Fuzzy logic role-based expert system decision-support system knowledge graph Internet of Things ICU resource management Neo4J graph database

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Enhancing scalability of peer-to-peer energy markets using adaptive segmentation method

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Journal of Modern Power Systems and Clean Energy 2019年第4期7卷 791-801页

作者： Mohsen KHORASANY Yateendra MISHRA Behrouz BABAKI Gerard LEDWICH Department of Electrical Engineering and Computer Science Queensland University of TechnologyBrisbaneAustralia Polytechnique Montréal MontréalCanada

This paper proposes an adaptive segmentation method as a market clearing mechanism for peer-to-peer(P2P)energy trading scheme with large number of market *** the proposed method,market players participate in the market by announcing their *** the first step,players are assigned to different segments based on their features,where the balanced k-means clustering method is implemented to form *** segments are formed based on the similarity between players,where the amount of energy for trade and its corresponding price are considered as features of *** the next step,a distributed method is employed to clear the market in each segment without any need to private information of *** novelty of this paper relies on developing an adaptive algorithm for dividing large number of market players into multiple segments to enhance scalability of the P2P trading by reducing data exchange and communication *** proposed approach can be used along with any distributed method for market *** this paper,two different structures including community-based market and decentralized bilateral trading market are used to demonstrate the efficacy of the proposed *** results show the beneficial properties of the proposed segmentation method.

关键词： Energy trading Market segmentation Distributed optimization Peer-to-peer(P2P)market alternating direction method of multipliers

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Transport Properties of K_xV_2O_5·nH_2O Nanocrystalline Films

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Journal of Materials Science & Technology 2011年第10期27卷 865-872页

作者： A.A.Bahgat H.A.Mady A.S.Abdel Moghny A.S.Abd-Rabo Samia E.Negm Department of Physics Faculty of ScienceAl-Azhar University

Five different compositions of KxV2O5-nH2O （where prepared by the sol-gel process. Electrical conductiv x=0.00, 0.0017, 0.0049, 0.0064 and 0.0091 mol） were ty and thermoelectric power were measured parallel to the substrate surface in the temperature range of 300-480 K. The electrical conductivity showed that all samples were semiconductors and that conductivity increased with increasing K content. The conductivity of the present system was primarily determined by hopping carrier mobility. The carrier density was evaluated as well. The conduction was confirmed to obey non-adiabatic small polaron hopping. The thermoelectric power or Seebeck effect, increased with increasing K ions content. The results obtained indicated that an n-type semiconducting behavior within the temperature range was investigated.

关键词： Vanadium pentoxide xerogel Nanocrystalline film Electrical conductivity Small polaron hopping

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A Study of Traveling Wave Structures and Numerical Investigation of Two-Dimensional Riemann Problems with Their Stability and Accuracy

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Computer Modeling in Engineering & Sciences 2023年第3期134卷 2193-2209页

作者： Abdulghani Ragaa alharbi Department of Mathematics College of ScienceTaibah UniversityAl-Madinah Al-Munawarah42353Saudi Arabia

The Riemann wave system has a fundamental role in describing waves in various nonlinear natural phenomena,for instance,tsunamis in the *** paper focuses on executing the generalized exponential rational function approach and some numerical methods to obtain a distinct range of traveling wave structures and numerical results of the two-dimensional Riemann *** stability of obtained traveling wave solutions is analyzed by satisfying the constraint conditions of the Hamiltonian *** simulations are investigated via the finite difference method to verify the accuracy of the obtained *** extract the approximation solutions to the underlying problem,some ODE solvers in FORTRAN software are applied,and outcomes are shown *** stability and accuracy of the numerical schemes using Fourier’s stabilitymethod and error analysis,respectively,to increase the reassurance are investigated.A comparison between the analytical and numerical results is obtained and graphically *** proposed methods are effective and practical to be applied for solving more partial differential equations(PDEs).

关键词： The Riemann wave equation Hamiltonian system solitary solutions numerical solutions stability accuracy

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Hydro-Geophysical Investigations for the Purposes of Groundwater Artificial Recharge in Wadi al-Butum Area, Jordan

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Journal of Water Resource and Protection 2012年第7期4卷 507-515页

作者： Hani al-Amoush Earth and Environmental Sciences Department Al al-Bayt University Mafraq Jordan

In this article, the potential for artificial groundwater recharge of Wadi al-Butum catchments area - Jordan is studied, using geoelectrical resistivity surveys and hydro geochemical methods with the aim of storing some of surface water during flood events times to be recharged in the groundwater as an essential part of integrated water resources management. The results of geoelectrical surveys show the existence of potential zones of alluvial deposits to store and recharge the groundwater aquifers. The hydro-geochemical modeling results show an overall upgrading of the original groundwater quality could be expected.

关键词： VES Hydro-Geophysics Artificial Recharge Wadi-al-Butum

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Evaluating the Effect of algal Extracts against Ultraviolet B-Induced Skin Damage in BalB/c Mice

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Journal of Environmental Science and Engineering(B) 2015年第11期4卷 583-590页

作者： Abdullah Trad al-fawwaz Mariam Abu-al-Basal Hala ali Tawil Department of Biological Sciences Al al-Bayt University Mafraq 25113 Jordan

Ethanol extract of mixed algae--spirogyra and ulothrix was investigated to assess the effect on some biochemical parameters in UVB irradiated mice. The dorsal-thoracic region of mice were shaved and exposed to UVB radiation for 24 h for two consecutive weeks. Five groups of ten mice each were conducted： non-irradiated control and irradiated control. Mice treated with commercial cream （S.M.） at a dose of 0.1 mg/cm2 and mice treated with ethanol extract of mixed spirogyra and ulothrix at a dose of 0.1 mg/cm2 or 0.2 mg/cm2. Topical application was performed to all treated mice groups once a day for four consecutive weeks. Results showed significant differences between treated and control groups during the whole period of experiment. The clear potentiality of the ethanol extract was detected through body and skin weight, level of total protein, Superoxide Dismutase （SOD） and Catalase （CAT） activities in skin. However, UVB irradiated mice treated with 0.2 mg/cm2 exhibited the most significant effect when compared to control groups. That may be attributed to anti-inflammatory and anti-oxidant effects of algal extract.

关键词： algae ultraviolet radiation photoprotective

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