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Exploration of structural,optical,and photoluminescent properties of (1-x)NiCo_(2)O_(4)/xPbS nanocomposites for optoelectronic applications

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Chinese Physics B 2022年第6期31卷 663-670页

作者： Zein K Heiba mohamed Bakr mohamed noura m farag Ali Badawi Physics Department Faculty of ScienceAin Shams UniversityCairoEgypt Physics Department Faculty of ScienceTaibah UniversityAl-Madina al MunawarahSaudi Arabia Department of Physics College of ScienceTaif UniversityP.O.Box 11099Taif 21944Saudi Arabia Department of Physics University College of TurabahTaif UniversityP.O.Box 11099Taif 21944Saudi Arabia

The(1-x)NiCo_(2)O_(4)/x PbS(0≤x≤0.2)nanocomposite samples are synthesized using the hydrothermal and thermolysis *** different phases developed in the obtained nanocomposite samples are accurately determined using the x-ray diffraction technique equipped with a *** percentage of the formed phases(NiCo_(2)O_(4)(NCO),PbS,PbSO_(4)),structural and microstructure parameters are determined using Rietveld quantitative phase *** transmission electron microscope(TEm)images and Rietveld analysis reveal almost isotropic particle size in the nano range with a very narrow size *** obtained phase percentage of PbS and PbSO4are smaller than nominated values(x)suggesting dissolving of some Pb and S ions into NCO which is then confirmed by the analysis of Fourier-transform infrared(FTIR)spectra of nanocomposite *** absorption spectra are modified upon doping NCO with *** optical band gaps of the nanocomposites increase as the amount of PbS *** effect of alloying on extinction coefficient,refractive index,dielectric constant,optical conductivity,the intensity,and emitted color from the photoluminescence of the nanocomposite samples are also *** refractive index value of NCO and NCO-PbS nanocomposite samples exhibit normal *** photoluminescent measurements reveal that the NCO-PbS nanocomposites can emit a violet *** improvement in the values of the nonlinear optical(NLO)parameters of pristine NCO at high frequencies or the nanocomposite samples at low frequencies,are made them used in NLO photonic devices.

关键词： Co_(2)O_(4)and PbS nanocomposite FTIR optical photoluminescence

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Artificial Intelligence Prediction of One-Part Geopolymer Compressive Strength for Sustainable Concrete

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Computer modeling in Engineering & Sciences 2024年第10期141卷 525-543页

作者： mohamed Abdel-mongy mudassir Iqbal m.farag Ahmed.m.Yosri Fahad Alsharari Saif Eldeen A.S.Yousef Department of Civil Engineering College of EngineeringJouf UniversitySakaka72388Saudi Arabia Department of Civil Engineering University of Engineering and TechnologyPeshawar54890Pakistan Civil Engineering Department Faculty of EngineeringAl-Azhar UniversityCairo11884Egypt Civil Engineering Department Faculty of EngineeringAswan UniversityAswan81528Egypt

Alkali-activated materials/geopolymer(AAms),due to their low carbon emission content,have been the focus of recent studies on ecological *** terms of performance,fly ash and slag are preferredmaterials for precursors for developing a one-part ***,determining the optimum content of the input parameters to obtain adequate performance is quite challenging and scarcely ***,in this study,machine learning methods such as artificial neural networks(ANN)and gene expression programming(GEP)models were developed usingmATLAB and GeneXprotools,respectively,for the prediction of compressive strength under variable input materials and content for fly ash and slag-based one-part *** database for this study contains 171 points extracted from literature with input parameters:fly ash concentration,slag content,calcium hydroxide content,sodium oxide dose,water binder ratio,and curing *** performance of the two models was evaluated under various statistical indices,namely correlation coefficient(R),mean absolute error(mAE),and rootmean square error(RmSE).In terms of the strength prediction efficacy of a one-part geopolymer,ANN outperformed *** and parametric analysis were also performed to identify the significant contributor to *** to a sensitivity analysis,the activator and slag contents had the most effects on the compressive strength at 28 *** water binder ratio was shown to be directly connected to activator percentage,slag percentage,and calcium hydroxide percentage and inversely related to compressive strength at 28 days and curing temperature.

关键词： Artificial intelligence techniques one-part geopolymer artificial neural network gene expression modelling sustainable construction polymers

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Insights into the hydrogen evolution reaction in vanadium redox flow batteries:A synchrotron radiation based X-ray imaging study

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Journal of Energy Chemistry 2024年第4期91卷 132-144页

作者： Kerstin Köble Alexey Ershov Kangjun Duan monja Schilling Alexander Rampf Angelica Cecilia Tomášfaragó marcus Zuber Tilo Baumbach Roswitha Zeis Helmholtz Institute Ulm Karlsruhe Institute of Technology89081 UlmGermany Laboratory for Applications of Synchrotron Radiation Karlsruhe Institute of Technology76131 KarlsruheGermany Institute for Photon Science and Synchrotron Radiation Karlsruhe Institute of Technology76344 Eggenstein-LeopoldshafenGermany Department of Electrical Electronicsand Communication EngineeringFaculty of EngineeringFriedrich-Alexander-Universität Erlangen-Nürnberg(FAU)91058 ErlangenGermany Department of mechanical and Industrial Engineering University of TorontoToronto M5S 3G8OntarioCanada

The parasitic hydrogen evolution reaction(HER)in the negative half-cell of vanadium redox flow batteries(VRFBs)causes severe efficiency ***,a deeper understanding of this process and the accompanying bubble formation is *** benchmarking study locally analyzes the bubble distribution in thick,porous electrodes for the first time using deep learning-based image segmentation of synchrotron X-ray *** large three-dimensional data set was processed precisely in less than one minute while minimizing human errors and pointing out areas of increased HER activity in *** study systematically varies the electrode potential and material,concluding that more negative electrode potentials of-200 m V *** hydrogen electrode(RHE)and lower cause more substantial bubble formation,resulting in bubble fractions of around 15%–20%in carbon felt ***,the bubble fractions stay only around 2%in an electrode combining carbon felt and carbon *** detected areas with high HER activity,such as the border subregion with more than 30%bubble fraction in carbon felt electrodes,the cutting edges,and preferential spots in the electrode bulk,are potential-independent and suggest that larger electrodes with a higher bulk-to-border ratio might reduce HER-related performance *** described combination of electrochemical measurements,local X-ray microtomography,AI-based segmentation,and 3D morphometric analysis is a powerful and novel approach for local bubble analysis in three-dimensional porous electrodes,providing an essential toolkit for a broad community working on bubble-generating electrochemical systems.

关键词： Vanadium redox flow battery Synchrotron X-ray imaging Tomography Hydrogen evolution reaction Gas bubbles Deep learning

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A STABILITY THEOREm FOR CONSTRAINED OPTImAL CONTROL PROBLEmS

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Journal of Computational mathematics 2004年第5期22卷 633-640页

作者： m.H.farag DepartmentofmathematicsandComputerScienceFacultyofEducation lbriSultanateofOman

This paper presents the stability of difference approximations of an optimal control problem for a quasilinear parabolic equation with controls in the coefficients, boundary conditions and additional restrictions. The optimal control problem has been convered to one of the optimization problem using a penalty function technique. The difference approximations problem for the considered problem is obtained. The estimations of stability of the solution of difference approximations problem are proved. The stability estimation of the solution of difference approximations problem by the controls is obtained.

关键词： Finite difference method Optimal control Penalty function methods Quasilinear Parabolic equations Stability estimations

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Current medical therapy of inflammatory bowel disease

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World Journal of Gastroenterology 2000年第4期6卷 483-489页

作者： Kiron m. Das Sherif A. farag Department of medicine Division of Gastroenterology and Hepatologyand Crohn's and Colitis Center of New JerseyUMDNJ Robert Wood Johnson Medical SchoolNew BrunswickNJ 08903USA

INTRODUCTIONThe 1990’s have brought a significant promise and the hopefor a better and brighter future in the new millennium forpatients with inflammatory bowel disease(IBD).A betterunderstanding of the pathophysiolo... 详细信息

关键词： ulcerative colitis Crohn’s disease therapy sulfasalazine 5-aminosalicylic acid glucocorticoids immunosuppresive agents immunomodulatory agents antibiotics nutrition

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maximizing the Benefit of Rate Transient Analysis for Gas Condensate Reservoirs

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Energy Engineering 2021年第5期118卷 1411-1423页

作者： mahmoud Abdo Tantawy Ahmed A.m.Elgibaly Ahmed mohamed farag Faculty of Petroleum and mining Engineering Suez UniversitySuezEgypt Abu Qir Petroleum Company AlexandriaEgypt

In recent years,many trials have been made to use the Rate Transient Analysis(RTA)techniques as a method to describe the gas condensate *** problem with using these techniques is the multi-phase behavior of the gas condensate ***,the Pressure Transient Analysis(PTA)is commonly used in this case to analyze the reservoir *** this paper,we are going to compare the results of both PTA and RTA of three wells in gas condensate *** comparison showed a great match between the results of the two mentioned techniques for the first time using a reference GOR of 75,000 SCF/***,we concluded that we could depend on RTA instead of PTA to spare the cost associated with the PTA in the gas condensate reservoirs.

关键词： Rate transient analysis production data analysis well testing permeability skin factor gas condensate

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Separation of rare earth elements from sulfate leach liquor by heterocyclic nitrogen compound

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Journal of Rare Earths 2008年第4期26卷 544-551页

作者： GHADA m. mahmoud NABIL T. El Hazek AHmAD m. farag OmNEYA m. El Hussaini Nuclear materials Authority P.O. Box 530 El Maadi Cairo Egypt Chemistry department Faculty of Science Cairo University Giza Egypt

Separation of rare earth dements by solvent extraction has actually been widely used in various fields from analytical chemistry to hydrometallurgy. A representative ore sample obtained from Kadabora Batholiths-Eastern Desert of Egypt, containing the multiple oxides rare earth minerals： Samarskite, Fergusonite, Betafite, and Pyrochlore, was subjected to sulfuric acid leaching. Different sets of equilibrium loading experiments were carded out on a bench scale for the extraction of rare earths （cerium and yttrium） from the sulfate leach liquor using 8,9-dihydro[1,2,4]triazolo[1,5-a]quinazolin-6（TH）-one {TQ} dissolved in methylene chloride. Stripping was carded out by 20% sodium hydroxide. A rare earth cake was produced by oxalic acid precipitation. Its purity reached 87.3%.

关键词： triazolopyrimidine extraction stripping precipitation rare earths

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Citrus reticulata Blanco (the common mandarin) fruit:An updated review of its bioactive,extraction types,food quality,therapeutic merits,and bio-waste valorization practices to maximize its economic value

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Food Bioscience 2022年第3期47卷 67-80页

作者： mohamed Shorbagi Nesrin m.Fayek Ping Shao mohamed A.farag Department of Special Chemistry Faculty of ScienceBenha UniversityAl Qalyubia GovernorateEgypt Pharmacognosy Department College of PharmacyCairo UniversityKasr El Aini st.11562CairoEgypt College of Food Science and Technology Zhejiang University of TechnologyZhejiangHangzhou310014PR China

Fruits are regarded as the richest dietary sources of polyphenols,carotenoids,terpenoids,and limonoids,making them highly desired prospects for the functional food *** waste that remains after fruit processing is also regarded as a valuable source of value-added phytochemicals.A comprehensive analysis of mandarin composition as a determinant of fruit functional properties,health benefits,and valorization into useful products is represented together with the effect of different processes such as light,wax coating,auxin addition,ozone treatment,and ethylene *** reviewing evidence is an essential precondition for improving the selling market of mandarin and highlighting its waste valorization potential and its incorporation into useful products produced by pharmaceutical *** this study,the phytochemical and biological reports presented to emphasize the needed priority for agricultural techniques to provide a certain mandarin product or *** addition,the paper summarizes the optimum conditions applied for the updated extraction techniques for phenolic acids,flavonoids,and oils at a commercial scale from mandarin peels and to enhance its global marketing.A brief representation is given towards potential mandarin patents and the valorization of its bio-waste fruits into commercial products of added *** review can guide researchers to produce future potentially marketed functional food enriched with mandarin extracts and/or bioactives.

关键词： Citrus reticulata Phytochemical composition Biological effects Waste valorization Extraction techniques Processing effect

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Thermochemical Aspects of Activated Ammonium Perchlorates with Superior Thermal Stability,Decomposition Enthalpy,Propagation Index,and Decomposition Kinetic Parameters

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Journal of Thermal Science 2021年第6期30卷 2196-2201页

作者： SHERIF Elbasuney m.Yehia SHUKRI Ismael SHERIF farag AHmED Saleh GHARIEB S.El-Sayyad Head of Nanotechnology Research Center Military Technical College(MTC)Cairo 11646Egypt School of Chemical Engineering Military Technical College(MTC)Cairo 11646Egypt Science and Technology Center of Excellence Cairo 11646Egypt Drug Radiation Research Department National Center for Radiation Research and Technology(NCRRT)Egyptian Atomic Energy Authority(EAEA)Cairo 11646Egypt

Ammonium perchlorate(AP)includes oxidizing and reducing elements on the same *** can act as an efficient oxidizer and mono-propellant as *** this study,AP experienced crystallographic phase change from orthorhombic centrosymmetric to non-centrosymmetric under controlled isothermal heat *** diffractograms confirmed this crystallographic phase *** thermal behaviour of activated AP had been investigated using *** AP demonstrated high chemical stability with an increase in endothermic phase transition enthalpy by 170%.The enthalpy of the subsequent two main exothermic decomposition reactions was increased by 250%.Whereas AP demonstrated total decomposition enthalpy of 733 J/g,activated AP showed 2614 J/*** AP can secure self-sustained response at a high *** index(combustion enthalpy/ignition temperature)was employed to assess self-sustained reaction *** AP demonstrated high propagation index of 8.7 compared with 2.5 for un-activated *** decomposition kinetic parameters had investigated using Kissinger and KAS *** AP showed an increase in activation energy by 89%using the Kissinger method;kinetic parameters using the KAS method were in good agreement with the Kissinger *** can have concluded that AP with novel kinetic decomposition parameters for enhanced safety storage and high combustion characteristics has evolved.

关键词： solid propellants oxidizers thermal behavior Kinetic parameters activation energy

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Portable rainfall simulator for plot-scale investigation of rainfall-runoff,and transport of sediment and pollutants

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International Journal of Sediment Research 2019年第1期34卷 38-47页

作者： Julien Boulange farag malhat Piyanuch Jaikaew Kazuki Nanko Hirozumi Watanabe Department of International Environmental and Agricultural SciencesGraduate School of AgricultureTokyo University of Agriculture and Technology Department of Pesticide Residues and Environmental Pollution Central Agricultural Pesticide LaboratoryAgriculture Research Center Department of Agricultural and Environmental Engineering United Graduate School of Agricultural ScienceTokyo University of Agriculture and Technology Department of Civil and Environmental Engineering Faculty of Science and engineeringKasetsart UniversityChalermphrakiat Sakon Nakhon Provice Campus Department of Disaster Prevention Meteorology and HydrologyForestry and Forest Products Research Institute

A low-cost, simple to use portable rainfall simulator is developed for use over a 5 m2plot. The simulator is easy to transport and assemble in the field, thereby allowing for necessary experimental replicates to be done. It provides rainfall intensities of between 20 and 100 mm/h by changing the number and type of silicon nozzles used. The Christiansen coefficient of uniformities obtained in the field are appropriate and vary from 79 to 94% for rainfall intensities ranging from 30 to 70 mm/h. In addition, the median volumetric drop diameters measured for rainfall intensities of 30, 50, and 70 mm/h are in the lower range of that of natural rainfall and equal to 1.10 ± 0.08,1.69 ± 0.21, and 1.66 ± 0.20 mm, respectively. The velocities of the raindrops with diameters less than 1.2 mm reached terminal velocities, while raindrops less than 2.0 mm achieved velocities reasonably close to the terminal velocity of natural rainfall. Furthermore,the average time-specific kinetic energy(KET) for rainfall intensities of 30, 50, and 70 mm/h are 257.7,760.1, and 1645.2 J/m2/h, respectively accounting for about 78.0 and 86.5% of the KET of natural rainfall for50 and 70 mm/h rainfall intensity, respectively. The applicability of the portable rainfall simulator for herbicide transport study is investigated using two herbicides(atrazine and metolachlor); herbicide losses in runoff and sediment samples are in the ranges reported in the literature. As a percentage of the amount of herbicide applied, 5.29% of atrazine and 2.15% of metolachlor are lost due to combined water and sediment runoff. The results show that the portable rainfall simulator can be effectively used in studying processes such as pesticide runoff, infiltration mechanisms, and sediment generation and transport at a field plot scale with an emphasis on how surface characteristics such as slope and soil properties affect these processes.

关键词： Rainfall simulator Rainfall intensity Raindrop energy Raindrop size distribution Rainfall uniformity

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