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Amination of biochar surface from watermelon peel for toxic chromium removal enhancement

Chinese Journal of Chemical Engineering 2021年第8期34卷 199-222页

作者： mohamed a.el-nemr Ibrahim M.A.Ismail Nabil M.Abdelmonem Ahmed el nemr Safaa Ragab Department of Chemical Engineering Faculty of EngineeringCairo UniversityGizaEgypt Renewable Energy Program Zewail City of Science and TechnologyEgypt Environmental Division National Institute of Oceanography and FisheriesKayet BeyEl-AnfoushyAlexandriaEgypt

Watermelon peel residues were used to produce a new biochar by dehydration *** new biochar has undergone two methods of chemical modification and the effect of this chemical modification on its ability to adsorb Cr(VI)ions from aqueous solution has been *** biochars,Melon-B,Melon-BO-NH_(2) and Melon-BO-TETA,were made from watermelon peel via dehydration with 50%sulfuric acid to give Melon-B followed by oxidation with ozone and amination using ammonium hydroxide to give Melon-BO-NH_(2) or Triethylenetetramine(TETA)to give *** prepared biochars were characterized by BET,BJH,SEM,FT-IR,TGA,DSC and EDAX *** highest removal percentage of Cr(VI)ions was 69%for Melon-B,98%for Melon-BO-NH_(2) and 99%for Melon-BO-TETA biochars of 100 mg·L^(−1) Cr(VI)ions initial concentration and 1.0 g·L^(−1) adsorbents *** unmodified biochar(Melon-B)and modified biochars(Melon-BO-NH_(2) and Melon-BO-TETA)had maximum adsorption capacities(Q_(m))of 72.46,123.46,and 333.33 mg·g^(−1),*** amination of biochar reduced the pore size of modified biochar,whereas the surface area was *** obtained data of isotherm models were tested using different error function *** Freundlich,Tempkin and Langmuir isotherm models were best fitted to the experimental data of Melon-B,Melon-BO-NH_(2) and Melon-BO-TETA,*** adsorption rate was primarily controlled by pseudo-second–order rate ***,the functional groups interactions are important for adsorption mechanisms and expected to control the adsorption *** adsorption for the Melon-B,Melon-BO-NH_(2) and Melon-BO-TETA could be explained for acid–base interaction and hydrogen bonding interaction.

关键词： Waste treatment Powder technology Citrullus lanatus Hexavalent chromium Biochar amination Adsorption

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Optimized system for combined production of electricity/green hydrogen for multiple energy pathways:a case study of Egypt

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Clean Energy 2024年第4期8卷 219-236页

作者： Reda Ragab mohamed HamdiHafez a.el Salmawy mohamed A.Ismail Mechanical Power Engineering Department Zagazig UniversityZagazig 44519Egypt Mechanical Engineering Department College of EngineeringKing Faisal UniversityAl-Ahsa 31982Saudi Arabia

By optimal sizing of a wind/photovoltaic hybrid renewable-energy(RE)system,trimming the surplus capacity to reduce the fluctuations in the electricity supplied to the grid,and using it to produce green hydrogen through electrolysis,a stable output with maximum possible capacity factor(CF)is generated to maintain the electricity grid ***,the trimmed energy is used in a secondary conversion path that minimizes the weighted average cost of the energy generated from the entire *** surplus power-to-gas conversion allows the use of green hydrogen to produce electricity,methanol,or ammonia subject to the resource availability,site characteristics,and financial *** on robust site selection criteria,the best performance is obtained at two sites:Ras Ghareb and Minya,achieving the lowest energy cost with some variance in their *** the Ras Ghareb site,the optimally sized RE plant provided the grid with a quasi-steady capacity of 423 MW with a CF of 80.04%and was capable of injecting 2965.8648 GWh throughout the year with the lowest cost of 2.4355¢/kWh.A surplus of 3.9%of the total energy produced from the plant was directed to produce 1922-ton H_(2)/year,achieving the lowest cost of hydrogen production of$1.9745/kg H_(2).For the other selected site,Minya,the clipped energy is used to produce 3330.47-ton H_(2)/year with an optimized lowest cost of$3.5268/kg H_(2).The difference in hydrogen costs was attributed to the number of full operating hours of the electrolyser in both *** cost is mainly affected by the electricity price and the electrolyser *** both tending to decrease,future forecasts show hydrogen cost reductions.

关键词： hybrid renewable-energy system(HRES) green hydrogen electrolysis power-to-gas methanol ammonia

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Effective participation of wind turbines in frequency control of a two-area power system using coot optimization

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Protection and Control of Modern Power Systems 2023年第1期8卷 230-244页

作者： Mahmoud Hussain el-Bahay Mohammed elsayed Lotfy mohamed a.el-Hameed electrical Power and Machines Department Faculty of EngineeringZagazig UniversityZagazig 44519Egypt ECEN Department Faculty of EngineeringA’Sharqiyah University400 IbraOman

In this paper,load frequency control is performed for a two-area power system incorporating a high penetration of renewable energy sources.A droop controller for a type 3 wind turbine is used to extract the stored kinetic energy from the rotating masses during sudden load *** auxiliary storage controller is applied to achieve effec-tive frequency *** coot optimization algorithm(COA)is applied to allocate the optimum parameters of the fractional-order proportional integral derivative(FOPID),droop and auxiliary storage *** fitness function is represented by the summation of integral square deviations in tie line power,and Areas 1 and 2 frequency *** robustness of the COA is proven by comparing the results with benchmarked optimizers including:atomic orbital search,honey badger algorithm,water cycle algorithm and particle swarm *** assessment is confirmed in the following four scenarios:(i)optimization while including PID controllers;(ii)optimization while including FOPID controllers;(iii)validation of COA results under various load disturbances;and(iv)validation of the proposed controllers under varying weather conditions.

关键词： Coot optimizer FOPID Load frequency control Photovoltaic Variable speed wind turbine

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Mineralogical and geochemical characterization of the Wadi Natash volcanic field(WNVF),Egypt:Alkaline magmatism in a Late Cretaceous continental rift system

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Acta Geochimica 2024年第6期43卷 1169-1191页

作者： a.el A.Surour Ahmed A.Madani mohamed a.el-Sharkawi Department of Geological Sciences Faculty of ScienceGalala UniversityNew Galala City 43511Egypt Geology Department Faculty of ScienceCairo UniversityGiza 12613Egypt

The Wadi Natash volcanic field(WNVF)in the south of the Eastern Desert of Egypt is a typical example of well-preserved intraplate alkaline magmatism during the Late Cretaceous,i.e.,prior to the Oligo-Miocene Red Sea *** compiled stratigraphic sections at two sectors;na.ely East Gabal Nuqra and West Khashm Natash(WKN)where the volcanic flows are intercalated with the Turonian Abu Agag sandstone with occasional paleosols when volcanic activity is *** mantle xenoliths are encountered in the first sector whereas flows in the second sector are interrupted by trachyte plugs and ring *** a geochemical basis,the maifc melt originating from the lithospheric mantle beneath the WNVF practiced~5%partial melting of phlogopite-bearing garnet *** dominate in the two sectors and highly evolved(silicic)rocks are confined to the WKN *** of ancient Precambrian fractures following the NW-SE and ENE-WSW trends facilitated the ascend of Late Cretaceous mantle-derived alkaline ***,the WNVF developed at the eastern shoulder of the so-called"Kom Ombo-Nuqra-Kharit rift system"that represents a well-defined NW-trending intracontinental rift basin in the southern Eastern *** such a structural setup,the Natash volcanic are confined to half-grabens at the East Gabal Nuqra sector whereas the West Khashm Natash sector is subjected to extensional stresses that propagated *** WNVF is a typical example of fluvial clastics(Turonian)intercalation with rift-related alkaline volcanic rocks in northeast Africa.

关键词： Wadi Natash volcanic field Late Cretaceous Lithostratigraphy Intraplate rift Abu Agag sandstone Clastic facies

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Mafic and felsic magmatism in the Wadi Kalalat area, South Eastern Desert, Egypt: mineralogy, geochemistry and geodynamic evolution during the Neoproterozoic in the Nubian Shield

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Acta Geochimica 2024年第1期43卷 150-173页

作者： a.el A.Surour Ahmed A.Madani mohamed a.el-Sobky Faculty of Science Galala UniversityNew Galala CitySuez 43511Egypt Department of Geology Faculty of ScienceCairo UniversityGiza 12613Egypt Egyptian Mineral Resources Authority P.O.Box 11517AbbasiyaCairoEgypt

In the south Eastern Desert of Egypt,two contrasting types of magmatism(mafic and felsic) are recorded in the Wadi Kalalat area,and form the Gabal el Motaghiarat and Gabal Batuga intrusions,*** two intrusions post-dates ophiolitic and arc associations represented by serpentinite and metagabbro-diorite,*** mafic intrusion has a basal ultramafic member represented by fresh peridotite,which is followed upward by olivine gabbro and anorthositic or *** mafic intrusion pertains to the Alaskan-type mafic-ultramafic intrusions in the Arabian-Nubian Shield(ANS)being of tholeiitic nature and emplaced in a typical arc *** the other hand,the Gabal Batuga intrusion comprises three varieties of fresh A-type granites of high K-calc alkaline nature,which is peraluminous and garnetbearing in parts.A narrow thermal aureole in the olivine gabbro of the mafic intrusion was developed due to the intrusion of the Batuga *** results in the development of a hornfelsic melagabbro variety in which the composition changed from tholeiitic to a calc-alkaline composition due to the addition of S_(i)O_(2),Al_(2)O_(3),alkalis,lithosphile elements(LILEs) such as Rb(70 ppm) and Y(28 ppm) from the felsic *** the thermal aureole,Rb amounts 2-8 ppm and Y lies in the range elieved that the Gabal Batuga felsic intrusion started to emplace during the waning stage of an arc system,with transition from the pre-collisional(i.e.,arc setting) to post-collisional and within plate *** from which the Gabal Batuga granites were fractionated is high-K calc-alkaline giving rise to a typical post-collisional A-type granite(A_(2)-subtype) indicating an origin from an underplating crustal ***,it is stressed here that the younger granites in the ANS are not exclusively post-collisional and within-plate but most likely they started to develop before closure of the arc *** possible source(s) of mafic magmas

关键词： Wadi Kalalat Gabal el Motaghairat mafic intrusion Gabal Batuga felsic intrusion Arc setting Post-collision Within-plate

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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

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Micro-fabrication of ceramics:Additive manufacturing and conventional technologies

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Journal of Advanced Ceramics 2021年第1期10卷 1-27页

作者： Hany HASSANIN Khamis ESSA Amr elSHAER mohamed IMBABY Heba H.el-MONGY Tamer a.el-SAYED School of Engineering Canterbury Christ Church UniversityCanterburyCT11QUUK University of Birmingham EdgbastonB152TTUK Kingston University London Penrhyn RoadKingston Upon ThamesSurreyKT12EEUK Department of Mechanical Design Faculty of EngineeringMatariaHelwan UniversityP.O.Box.11718CairoEgypt Jubail University College Mechanical EngineeringKingdom of Saudi Arabia Center for Applied Dynamics Research(CADR) School of EngineeringUniversity of AberdeenAberdeenAB243UEUK

Ceramic materials are increasingly used in micro-electro-mechanical systems(MEMS)as they offer many advantages such as high-temperature resistance,high wear resistance,low density,and favourable mechanical and chemical properties at elevated ***,with the emerging of additive manufacturing,the use of ceramics for functional and structural MEMS raises new opportunities and *** paper provides an extensive review of the manufacturing processes used for ceramic-based MEMS,including additive and conventional manufacturing *** review covers the micro-fabrication techniques of ceramics with the focus on their operating principles,main features,and processed *** that need to be addressed in applying additive technologies in MEMS include ceramic printing on wafers,post-processing at the micro-level,resolution,and quality *** paper also sheds light on the new possibilities of ceramic additive micro-fabrication and their potential applications,which indicates a promising future.

关键词： micro-electro-mechanical system(MEMS) micro-fabrication ceramics micro parts additive manufacturing

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Summary of the current guidelines for managing iatrogenic colorectal perforations and the evolving role of endoluminal vacuum therapy

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World Journal of Clinical Cases 2025年第6期13卷 1-8页

作者： Ahmed Tawheed Ibrahim Halil Bahcecioglu Mehmet Yalniz Mubin Ozercan Ali Cagri Oral mohamed el-Kassas Department of Endemic Medicine Faculty of MedicineHelwan UniversityCairo 11795Egypt Department of Gastroenterology Firat UniversityElazig 23119Türkiye Liver Disease Research Center College of MedicineKing Saud UniversityRiyadh 7805Saudi Arabia

Colonoscopy represents a safe procedure that is widely used in medical practice either to diagnose or treat various gastrointestinal *** the last few years,the incidence rate of perforations in colonoscopic procedures has increased,especially in therapeutic *** recent advancements in endoscopic techniques and gastrointestinal tumoral resection procedures such as endoscopic mucosal resection,endoscopic full-thickness resection,and endoscopic submucosal dissection(ESD)could be a risk factor for this increased *** incidence rate of mortality of serious colonoscopic perforations is 7.1%.The management plan for these perforations starts with conservative treatment in mild cases,endoscopic closure,and surgical management in severe ***,endoluminal vacuum therapy was found to be effective in the management of colorectal perforations and this has been reported in multiple case *** editorial provides an overview of the current guidelines for the management of iatrogenic colorectal *** insights are from the perspectives of endoscopists and *** also present a management algorithm based on the guidelines of the European Society of Gastrointestinal Endoscopy,the American Gastroenterological Association,and the World Society of Emergency *** also discussed in brief the use of endoluminal vacuum therapy in colorectal perforations.

关键词： Colon Rectum Iatrogenic colonic perforation Colonoscopy Guidelines Endovacuum Endolumical vacuum therapy Endoscopic management

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A Multi-Level Threshold Method for Edge Detection and Segmentation Based on Entropy

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Computers, Materials & Continua 2020年第4期63卷 1-16页

作者： mohamed a.el-Sayed Abdelmgeid A.Ali mohamed E.Hussien Hameda A.Sennary Department of Mathematics Faculty of ScienceFayoum UniversityFayoumEgypt.CurrentlyComputer Science DepartmentTaif UniversityTaifSaudi Arabia Computer Science Department Faculty of Computers and Information Minia UniversityMiniaEgypt Department of Mathematics Faculty of ScienceAswan UniversityAswanEgypt

The essential tool in image processing,computer vision and machine vision is edge detection,especially in the fields of feature extraction and feature *** is a basic area in information *** entropy,in image processing field has a role associated with image *** an initial step in image processing,the entropy is always used the image’s segmentation to determine the regions of image which is used to separate the background and objects in *** segmentation known as the process which divides the image into multiple regions or sets of *** applications have been development to enhance the image *** paper utilizes the Shannon entropy to achieve edge detection process and segmentation of the *** introduces a new method of edge detection for 2-D histogram and Shannon entropy based on multilevel *** method utilizes the gray value and the average gray value of the pixels to achieve the two dimensional *** current method has apriority in comparison to some upper classical *** experimental results exhibited that the proposed method could capture a moderate quality and execution time better than other comparative methods,particularly in the largest images *** proposed method offers good results when applied with images of different sizes from the civilization of ancient Egyptians.

关键词： Multi-level threshold edge detection 2D histogram entropy

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A comparative study of liquid and solid inner contact roxatidine acetate ion-selective electrode membranes

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Chinese Chemical Letters 2015年第6期26卷 714-720页

作者： mohamed K.Abd el-Rahman Hala E.Zaazaa Samah S.Abbas Badr el-Zeany Zeinab a.el-Sherif Dalia a.el-Haddad Analytical Chemistry Department Faculty of PharmacyCairo University National Organization for Drug Control and Research

A comparative study was conducted using two designs of a roxatidine acetate （ROX）-selective electrode; a conventional liquid inner contact called electrode A and a graphite-coated solid contact called electrode 13. The fabrication of electrodes was based on roxatidine-tetraphenylborate （ROX-TPB） as an ion-association complex in a PVC matrix using different plasticizers. electrode A has a linear dynamic range of 2.2 ×10^-5 mol/L to 1.0 ×10^-2 mol/L, with a Nernstian slope of 54.7 mV/decade and a detection limit of 1.4 ×10^-6 mol/L. electrode B shows linearity over the concentration range of 1.0×10^-6 mol/L to 1.0×10^-2 tool/L, with a Nernstian slope of 51.2 mV/decade and a limit of detection of 1.1×10^7 mol/L which is remarkably improved as a result of diminishing ion fluxes in this solid contact, ion-selective electrode. The proposed sensors display useful analytical characteristics for the determination of ROX in bulk powder and its pharmaceutical formulation. The present electrodes show clear discrimination of ROX from several inorganic, organic ions, sugars, some common drug excipients and the degradation product （3-[3-（1-piperidinyl methyl） phenoxy] propyl amine） of ROX. Furthermore, the proposed electrodes were utilized for the determination of ROX in human plasma, where electrode B covers drug Cmax which indicated its applicability to pharmacokinetic, bioavailability and bioequivalent studies. The results obtained by the proposed electrodes were statistically analyzed and compared with those obtained by a reported HPLC method. No significant difference for either accuracy or precision was observed.

关键词： Comparative study Roxatidine acetate Liquid inner contact electrode Solid contact electrode Degradation product Plasma

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