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Water conservation in the Arab region: a m.st for survival

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Research in Cold and Arid Regions 2013年第1期5卷 157-164页

作者： gamal m. abdo Abdin m. A. Salih Abdulm.hsen Al-Sheikh Civil Engineering Departm.nt University of Khartoum Sudan Alzam.l Group Chair King Saud University Riyadh Saudi Arabia

The Arab region covers an area over 13 m.llion square kilom.ters in size, with alm.st 90% of its area classified as arid or ex- trem.ly arid with very little precipitation, extrem.ly high evaporation and alm.st no vegetation cover. The region is classified in m.ny international reports as the poorest region in the world in the context of renewable water resources and critical water scarcity which hinders the socio-econom.ic developm.nt of m.ny countries in this region. The rapidly increasing population has reduced the per capita share of renewable water to less than the poverty line of 1,000 m./（capita＇a） and, in som. Arab countries, to less than the extrem. poverty line of 500 m./（capita＇a）. This has led to over-exploitation of non-renewable groundwater and desalination of salty water in m.ny countries with considerable costs and contam.nation of m.ny renewable sources. Atm.spheric processes re- sponsible for aridity in the Arab region are projected to intensify due to clim.te change, resulting in an alarm.ng decrease in pre- cipitation and increase in evaporation rates. m.ny concerned entities in the region consider water security as a key elem.nt for food security and ultim.tely political stability. Hence, various efforts have been exerted to identify key problem. and suggested solutions. The Arab Water m.nisters Council of the Arab League, as well as Reports of the Arab Forum.for the Environm.nt and Developm.nt （AFED） and the recom.endations of the 13th Regional m.eting of the Arab National Com.ittees of the Interna- tional Hydrological Program.e of UNESCO （niP）, have all m.de sim.lar recom.endations on the need to address the issues of water scarcity in the Arab region which will be further discussed in this paper. However, none of these reports focused on ＂Water Conservation＂ as an equally im.ortant action for coping with water scarcity in the region. There are m.ny definitions for ＂Water Conservation＂ in the scientific literature, including huge water savings

关键词： arid zone water scarcity water security irrigation efficiency clim.te change water harvesting water reuse

A statistical approach to enhance the productivity of Streptom.ces baarensis m.-133 for bioactive com.ounds

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Synthetic and System. Biotechnology 2024年第2期9卷 196-208页

作者： m.ham.d H.Kalaba gamal m.El-Sherbiny Osam. m.Darwesh Saad A.m.ghannem Botany and m.crobiology Departm.nt Faculty of Science(Boys)Al-Azhar UniversityCairo 11884Egypt Agricultural m.crobiology Departm.nt National Research CentreDokkiCairoEgypt

The goal of this study was to use statistical optim.zation to change the nutritional and environm.ntal conditions so that Streptom.ces baarensis m.-133 could m.ke m.re active *** trials were used to screen for critical variables influencing productivity using the Placket-Burm.n Design *** m.-133 is significantly influenced by elicitation,yeast extract,inoculum.size,and incubation period in term. of antibacterial activity.A total of 27 experim.ntal trials with various com.inations of these factors were used to carry out the response surface technique using the Box-Behnken *** analyses revealed that the m.del was highly significant(pm.nation(R2)of ***,the m.del predicted that the response as inhibition zone diam.ter would reach a value of 27 *** optim.l conditions,*** m.-133 produced 18.0 g of crude extract to each 35L and was purified with colum. *** active fraction exhibiting antibacterial activity was characterized using spectroscopic *** m.C and m.C values varied between 37.5 and 300μg/m. and 75 and 300μg/m.,*** conclusion,the biostatistical optim.zation of the active fraction critical variables,including environm.ntal and nutritional conditions,enhances the production of bioactive m.lecules by Streptom.ces species.

关键词： S.baarensis m.-133 Placket-Burm.n designBox-Behnken design ESKAPE Antibacterial activity

Ultralong hydroxyapatite-based forward osm.sis m.m.rane for freshwater generation

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Frontiers of Chem.cal Science and Engineering 2024年第9期18卷 37-49页

作者： m.ham.d gamal Gom.a Ham.y m.am.un Abdel-Ghafar Francesco Galiano Francesca Russo Alberto Figoli El-Sayed Ali Abdel-Aal Abdel-Hakim.Taha Kandil Bahaa Ahm.d Salah Central m.tallurgical Research and Developm.nt Institute(Cm.DI) 11421 CairoEgypt Chem.stry Departm.nt Faculty of ScienceHelwan University11795 CairoEgypt Institute on m.m.rane Technology(CNR-ITm. 87036 RendeItaly

Increasing global water shortages are accelerating the pace of m.m.rane m.nufacturing,which generates m.ny environm.ntally harm.ul *** challenges need a radical rethink of developing innovative m.m.ranes that can address freshwater production without generating environm.ntally harm.ul *** work utilized the synthesized ultra-long hydroxyapatite(UHA)by the solvotherm.l m.thod using the green solvent oleic acid in preparing UHA-based forward osm.sis *** m.m.ranes were developed using different loading ratios of graphene oxide(GO)by vacuum.assisted filtration *** prepared GO/UHA m.m.ranes were identified using X-ray diffraction,scanning electron m.croscope,Fourier-transform.infrared spectroscopy,and X-ray photoelectron *** contact angle and pore size distribution were determ.ned for the obtained GO/UHA *** obtained hierarchical porous structure in the prepared m.m.ranes with interconnected channels results in a stable water flux with reverse salt *** best water flux rate of 42±2 L·m.(–2)·h^(–1)was achieved using the 50 m. GO/UHA m.m.rane,which is 3.3 tim.s higher than the pristine m.m.rane,and a reverse salt flux of 67 g·m.(-2)·h^(–1).The obtained results showed a prom.sing capability of a new generation of sustainable inorganic-based m.m.ranes that can be utilized in freshwater generation by energy-efficient techniques such as forward osm.sis.

关键词： forward osm.sis ultra-long hydroxyapatite graphene oxide inorganic-based m.m.rane

Cosm.logical applications in Kaluza-Klein theory

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Chinese Physics B 2012年第4期21卷 631-637页

作者： m. I. Wanas gamal G. L. Nashed A. A. Nowaya Astronom. Departm.nt Faculty of Science Cairo University Giza Egypt m.them.tics Departm.nt Faculty of Science Ain Shams University Cairo 11566 Egypt Center for Theoretical Physics British University of Egypt Sherouk City 11837 P.O. Box 43 Egypt m.them.tics Departm.nt Faculty of Science King Faisal University P.O. Box 380 Al-Ahsaa 31982 the Kingdom of Saudi Arabia Egyptian Relativity Group (ERG) Physics Department Faculty of Science Monofia University Monofia Egypt

The field equations of Kaluz-Klein （KK） theory have been applied in the dom.in of cosm.logy. These equations are solved for a fiat universe by taking the gravitational and the cosm.logical constants as a function of tim. t. We use Taylor＇s expansion of cosm.logical function, A（t）, up to the first order of the tim. t. The cosm.logical param.ters are calculated and som. cosm.logical problem. are discussed.

关键词： Kaluz-Klein theory cosm.logy Taylor's expansion of cosm.logical function

Double com.ound com.ination synchronization am.ng eight n-dim.nsional chaotic system.

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Chinese Physics B 2018年第8期27卷 150-158页

作者： gamal m.m.hm.ud Tarek m.Abed-Elham.ed Ahm.d A Farghaly Departm.nt of m.them.tics Faculty of Science Assiut University

Depending on double com.ound synchronization and com.ound com.ination synchronization, a new kind of syn- chronization is introduced which is the double com.ound com.ination synchronization （DCCS） of eight n-dim.nsional chaotic system.. This kind m.y be considered as a generalization of m.ny types of synchronization. In the com.unica- tion, based on m.ny of drive and response system., the transm.tted and received signals will be m.re secure. Using the Lyapunov stability theory and nonlinear feedback control, analytical form.las of control functions are obtained to insure our results. The corresponding analytical expression and num.rical treatm.nt are used to show the validity and feasibility of our proposed synchronization schem.. The eight m.m.istor-based Chua oscillators are considered as an exam.le. Other exam.les can be sim.larly investigated. The proposed synchronization technique is supported using the m.TLAB sim.la- tion outcom.s. We obtain the sam. results of num.rical treatm.nt of our synchronization using sim.lation observations of our exam.le.

关键词： double com.ound synchronization com.ound com.ination synchronization chaotic system Lya-punov stability

Electronic Properties of Red P-Type Tl2S5 Single Crystals

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Chinese Physics Letters 2005年第6期22卷 1530-1532页

作者： G.A.gamal m.AbouZied A.A.Ebnalwaled Departm.ntofPhysics FacultyofScienceSouthValleyUniversityQena83511Egypt

Single crystals of red Tl2S5 were prepared by a special m.dified vertical Bridgm.n and Stockbarger technique. This growth was perform.d in our laboratory. The influences of tem.erature on the electrical conductivity, Hall m.bility, carrier concentration, and therm.electric power (TEP) were carried out in the tem.erature range 277–413K. Throughout these m.asurem.nts, various physical param.ters such as effective m.ss of charge carriers, carrier m.bility, diffusion coefficient, and the relaxation tim. for both m.jority and m.nority carriers were found.

关键词： TI USA K

Spherically sym.etric solution in higher-dim.nsional teleparallel equivalent of general relativity

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Chinese Physics B 2013年第2期22卷 120-127页

作者： gamal G.L.Nashed Center for Theoretical Physics British University in EgyptSherouk City 11837P.O.Box 43Egypt m.them.tics Departm.nt Faculty of ScienceAin Shams UniversityCairo11566Egypt

A theory of（N＋1）-dim.nsional gravity is developed on the basis of the teleparallel equivalent of general relativity（TEGR）.The fundam.ntal gravitational field variables are the（N＋1）-dim.nsional vector fields,defined globally on a m.nifold m.and the gravitational field is attributed to the *** form.of Lagrangian density is quadratic in torsion *** then give an exact five-dim.nsional spherically sym.etric solution（Schwarzschild（4＋1）-dim.nsions）.Finally,we calculate energy and spatial m.m.ntum.using gravitational energy-m.m.ntum.tensor and superpotential 2-form.

关键词： (N+1)-dim.nsional teleparallel equivalent of general relativity five-dim.nsional solution energy and m.m.ntum

Energy and m.m.ntum.of general spherically sym.etric fram.s on the regularizing teleparallelism

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Chinese Physics B 2012年第1期21卷 101-109页

作者： gamal G.L.Nashed Centre for Theoretical Physics The British University in EgyptEl-Sherouk City 11837Egypt m.them.tics Departm.nt Faculty of ScienceAin Shams University

In the context of the covariant teleparallel fram.work, we use the 2-form.translational m.m.ntum.to com.ute the total energy of two general spherically sym.etric fram.s. The first one is characterized by an arbitrary function H（r）, which preserves the spherical sym.etry and reproduces all the previous solutions, while the other one is characterized by a param.ter ξ which ensures the vanishing of the axial of trace of the torsion. We calculate the total energy by using two procedures, i.e., when the WeitzenbSck connection Гα^β is trivial, and show how H（r） and ξ play the role of an inertia that leads the total energy to be unphysical. Therefore, we take into account Гα^β and show that although the spacetim.s we use contain an arbitrary function and one param.ter, they have no effect on the form.of the total energy and m.m.ntum.as it should be.

关键词： gravitation teleparallel gravity energy-m.m.ntum conserved currents

Five-dim.nsional teleparallel theory equivalent to general relativity,the axially sym.etric solution,energy and spatial m.m.ntum

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Chinese Physics B 2011年第11期20卷 102-109页

作者： gamal G.L.Nashed m.them.tics Departm.nt Faculty of ScienceAin Shams University

A theory of （4＋1）-dim.nsional gravity is developed on the basis of the teleparallel theory equivalent to general relativity. The fundam.ntal gravitational field variables are the five-dim.nsional vector fields （pentad）, defined globally on a m.nifold m. and gravity is attributed to the torsion. The Lagrangian density is quadratic in the torsion tensor. We then give the exact five-dim.nsional solution. The solution is a generalization of the fam.liar Schwarzschild and Kerr solutions of the four-dim.nsional teleparallel equivalent of general relativity. We also use the definition of the gravitational energy to calculate the energy and the spatial m.m.ntum.

关键词： five-dim.nsional teleparallel equivalent of general relativity five-dim.nsional solution energy and spatial m.m.ntum