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Effect of nitrogen fertilization on yield, N content, and nitrogen fixation of alfalfa and smooth bromegrass grown alone or in mixture in greenhouse pots

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Journal of Integrative Agriculture 2015年第9期14卷 1864-1876页

作者： XIE Kai-yun LI Xiang-lin HE Feng ZHANG Ying-jun WAN Li-qiang David B Hannaway WANG Dong QIN Yan gamal m a fadul Institute of Animal Sciences Chinese Academy of Agricultural Sciences Institute of Grassland Science College of Animal Science and TechnologyChina Agricultural University Department of Crop and Soil Science Oregon State University

Planting grass and legume mixtures on improved grasslands has the potential advantage of realizing both higher yields and lower environmental pollution by optimizing the balance between applied N fertilizer and the natural process of legume biological nitrogen fixation. However, the optimal level of N fertilization for grass-legume mixtures, to obtain the highest yield, quality, and contribution of N2 fixation, varies with species. A greenhouse pot experiment was conducted to study the temporal dynamics of N2 fixation of alfalfa （medicago sativa L.） grown alone and in mixture with smooth bromegrass （Bromus inermis Leyss.） in response to the addition of fertilizer N. Three levels of N （0, 75, and 150 kg ha-1） were examined using 15N-labeled urea to evaluate N2 fixation via the 15N isotope dilution method. Treatments were designated NO （0.001 g per pot）, N75 （1.07 g per pot） and N150 （2.14 g per pot）. Alfalfa grown alone did not benefit from the addition of fertilizer N; dry matter was not significantly increased. In contrast, dry weight and N content of smooth bromegrass grown alone was increased significantly by N application. When grown as a mixture, smooth bromegrass biomass was increased significantly by N application, resulted in a decrease in alfalfa biomass. In addition, individual alfalfa plant dry weight （shoots＋roots） was significantly lower in the mixture than when grown alone at all N levels. Smooth bromegrass shoot and root dry weight were significantly higher when grown with alfalfa than when grown alone, regardless of N application level. When grown alone, alfalfa＇s N2 fixation was reduced with N fertilization （R2=0.9376,P=0.0057）. When grown in a mixture with smooth bromegrass, with 75 kg ha-1 of N fertilizer, the percentage of atmospheric N2 fixation contribution to total N in alfalfa （%Ndfa） had a maximum of 84.07 and 83.05% in the 2nd and 3rd harvests, respectively. Total 3-harvest %Ndfa was higher when alfalfa was grown in a mixture than when grow

关键词： alfalfa (medicago sativa) smooth bromegrass (Bromus inermis) nitrogen (N2) fixation nitrogen partitioning,15N mixture monoculture

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A statistical approach to enhance the productivity of Streptomyces baarensis mH-133 for bioactive compounds

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

作者： mohamed H.Kalaba gamal m.El-Sherbiny Osama m.Darwesh Saad A.moghannem Botany and microbiology Department Faculty of Science(Boys)Al-Azhar UniversityCairo 11884Egypt Agricultural microbiology Department National Research CentreDokkiCairoEgypt

The goal of this study was to use statistical optimization to change the nutritional and environmental conditions so that Streptomyces baarensis mH-133 could make more active *** trials were used to screen for critical variables influencing productivity using the Placket-Burman Design *** mH-133 is significantly influenced by elicitation,yeast extract,inoculum size,and incubation period in terms of antibacterial activity.A total of 27 experimental trials with various combinations of these factors were used to carry out the response surface technique using the Box-Behnken *** analyses revealed that the model was highly significant(pmination(R2)of ***,the model predicted that the response as inhibition zone diameter would reach a value of 27 *** optimal conditions,*** mH-133 produced 18.0 g of crude extract to each 35L and was purified with column *** active fraction exhibiting antibacterial activity was characterized using spectroscopic *** mIC and mBC values varied between 37.5 and 300μg/ml and 75 and 300μg/ml,*** conclusion,the biostatistical optimization of the active fraction critical variables,including environmental and nutritional conditions,enhances the production of bioactive molecules by Streptomyces species.

关键词： S.baarensis mH-133 Placket-Burman designBox-Behnken design ESKAPE Antibacterial activity

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Ultralong hydroxyapatite-based forward osmosis membrane for freshwater generation

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Frontiers of Chemical Science and Engineering 2024年第9期18卷 37-49页

作者： mohamed gamal Gomaa Hamdy maamoun Abdel-Ghafar Francesco Galiano Francesca Russo Alberto Figoli El-Sayed Ali Abdel-Aal Abdel-Hakim Taha Kandil Bahaa Ahmed Salah Central metallurgical Research and Development Institute(CmRDI) 11421 CairoEgypt Chemistry Department Faculty of ScienceHelwan University11795 CairoEgypt Institute on membrane Technology(CNR-ITm) 87036 RendeItaly

Increasing global water shortages are accelerating the pace of membrane manufacturing,which generates many environmentally harmful *** challenges need a radical rethink of developing innovative membranes that can address freshwater production without generating environmentally harmful *** work utilized the synthesized ultra-long hydroxyapatite(UHA)by the solvothermal method using the green solvent oleic acid in preparing UHA-based forward osmosis *** membranes were developed using different loading ratios of graphene oxide(GO)by vacuum-assisted filtration *** prepared GO/UHA membranes were identified using X-ray diffraction,scanning electron microscope,Fourier-transform infrared spectroscopy,and X-ray photoelectron *** contact angle and pore size distribution were determined for the obtained GO/UHA *** obtained hierarchical porous structure in the prepared membranes 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 mg GO/UHA membrane,which is 3.3 times higher than the pristine membrane,and a reverse salt flux of 67 g·m^(-2)·h^(–1).The obtained results showed a promising capability of a new generation of sustainable inorganic-based membranes that can be utilized in freshwater generation by energy-efficient techniques such as forward osmosis.

关键词： forward osmosis ultra-long hydroxyapatite graphene oxide inorganic-based membrane

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Double compound combination synchronization among eight n-dimensional chaotic systems

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

作者： gamal m mahmoud Tarek m Abed-Elhameed Ahmed A Farghaly Department of mathematics Faculty of Science Assiut University

Depending on double compound synchronization and compound combination synchronization, a new kind of syn- chronization is introduced which is the double compound combination synchronization （DCCS） of eight n-dimensional chaotic systems. This kind may be considered as a generalization of many types of synchronization. In the communica- tion, based on many of drive and response systems, the transmitted and received signals will be more secure. Using the Lyapunov stability theory and nonlinear feedback control, analytical formulas of control functions are obtained to insure our results. The corresponding analytical expression and numerical treatment are used to show the validity and feasibility of our proposed synchronization scheme. The eight memristor-based Chua oscillators are considered as an example. Other examples can be similarly investigated. The proposed synchronization technique is supported using the mATLAB simula- tion outcomes. We obtain the same results of numerical treatment of our synchronization using simulation observations of our example.

关键词： double compound synchronization compound combination synchronization chaotic system Lya-punov stability

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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 DepartmentofPhysics FacultyofScienceSouthValleyUniversityQena83511Egypt

Single crystals of red Tl2S5 were prepared by a special modified vertical Bridgman and Stockbarger technique. This growth was performed in our laboratory. The influences of temperature on the electrical conductivity, Hall mobility, carrier concentration, and thermoelectric power (TEP) were carried out in the temperature range 277–413K. Throughout these measurements, various physical parameters such as effective mass of charge carriers, carrier mobility, diffusion coefficient, and the relaxation time for both majority and minority carriers were found.

关键词： TI USA K

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Spherically symmetric solution in higher-dimensional 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 mathematics Department Faculty of ScienceAin Shams UniversityCairo11566Egypt

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

关键词： (N+1)-dimensional teleparallel equivalent of general relativity five-dimensional solution energy and momentum

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Investigation of a New Formula for Gurney Velocity Estimation

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火炸药学报 2018年第4期41卷 340-344页

作者： Tamer Elshenawy Ahmed Elbeih Qing ming Li gamal m. Abdo Technical Research Centre Cairo Egypt military Technical College Kobry Elkobbah Cairo Egypt The University of manchester School of Mechanical Aerospace and Civil Engineering Manchester UK mechanical Engineering Department Modern Acade

The formula for the analytical calculations of the shaped charge jetting parameters exhibit an explicit dependence upon the Gurney velocity of an explosive *** attempts have been done to approximate the characteristic constant 2E^(1/2) and to make its use more *** is shown herein that the characteristic Gurney velocity parameter depends on the ratio of the Chapman Jouguet-pressure to explosive impulse ratio by the formula:2E^(1/2)=0.2415(P_(CJ)/I_(SP)ρ_0)-970.76,where PCJis the Chapman Jouguet pressure(Pa),ISPis the specific impulse of the explosive used as a monopropellant(N·s/kg)andρois the explosive density(kg/m^3).The proposed empirical formula was found to be reasonable and quite accurate approximation that can be implemented over a wide range of explosives,where the maximum deviation between the measured and the calculated Gurney velocities was nearly 6%.Besides,the proposed approach has been used analytically to calculate the jet tip velocity of a small caliber shaped charge,which is measured *** difference between the measured and the calculated jet tip velocity was only 1.6%.

关键词：火药理论研究化学分析

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Energy and momentum of general spherically symmetric frames 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 mathematics Department Faculty of ScienceAin Shams University

In the context of the covariant teleparallel framework, we use the 2-form translational momentum to compute the total energy of two general spherically symmetric frames. The first one is characterized by an arbitrary function H（r）, which preserves the spherical symmetry and reproduces all the previous solutions, while the other one is characterized by a parameter 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 spacetimes we use contain an arbitrary function and one parameter, they have no effect on the form of the total energy and momentum as it should be.

关键词： gravitation teleparallel gravity energy-momentum conserved currents

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Five-dimensional teleparallel theory equivalent to general relativity,the axially symmetric solution,energy and spatial momentum

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

作者： gamal G.L.Nashed mathematics Department Faculty of ScienceAin Shams University

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

关键词： five-dimensional teleparallel equivalent of general relativity five-dimensional solution energy and spatial momentum

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Teleparallel equivalent theory of (1+1)-dimensional gravity

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Chinese Physics B 2010年第11期19卷 124-131页

作者： gamal G.L.Nashed mathematics Department Faculty of ScienceAin Shams UniversityCairoEgypt Centre for Theoretical Physics The Bvitish University in EgyptEl-Sherouk CityMisr-Ismalia Desert RoadPostal No.11837P.O.Box 43Egypt

A theory of （1＋1）-dimensional gravity is constructed on the basis of the teleparallel equivalent of general relativity. The fundamental field variables are the tetrad fields ei^μ and the gravity is attributed to the torsion. A dilatonic spherically symmetric exact solution of the gravitational field equations characterized by two parameters m and Q is derived. The energy associated with this solution is calculated using the two-dimensional gravitational energy- momentum formula.

关键词： teleparallel equivalent theory of (1+1)-dimensional gravity two-dimensional spherically symmetric dilatonic black hole energy

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