检索结果-南通市图书馆

Journal of Environmental Sciences 2018年第8期30卷 87-96页

作者： ahmed AlSayed ahmed Fergala ahmed Eldyasti Department of Civil Engineering Lassonde School of Engineering York University

Methanotrophic based process can be the remedy to offset the wastewater treatment facilities increasing energy requirements due to methanotroph＇s unique ability to integrate methane assimilation with multiple biotechnological applications like biological nitrogen removal and methanol production. Regardless of the methanotrophic process end product, the challenge to maintain stable microbial growth in the methanotrophs cultivation bioreactor at higher cell densities is one of the major obstacles facing the process upscaling. Therefore, a series of consecutive batch tests were performed to attentively investigate the biomass density influence on type I methanotrophs bacterial growth. In addition, food to microorganisms（F/M）, carbon to nitrogen（C/N） and nitrogen to microorganisms（N/M） ratio effect on the microbial activity was studied for the first time. It was clarified that the F/M ratio is the most influencing factor on the microbial growth at higher biomass densities rather than the biomass density increase, whereas C/N and N/M ratio change, while using nitrate as the nitrogen source,does not influence methanotrophs microbial growth. These study results would facilitate the scaling up of methanotrophic based biotechnology by identifying that F/M ratio as the key parameter that influences methanotrophs cultivation at high biomass densities.

关键词： Methanotrophs Wastewater treatment Food to microorganisms ratio Biomass density

On Learning Adaptive Service Compositions

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science and Systems Engineering 2021年第4期30卷 465-481页

作者： ahmed Moustafa Department of Computer Science Nagoya Institute of TechnologyGokiso-choShowa-kuNagoyaAichi466-8555Japan Faculty of Informatics Zagazig UniversityZagazigEgypt

Service composition is an important and effective technique that enables atomic services to be combined together to forma more powerful service,i.e.,a composite *** the pervasiveness of the Internet and the proliferation of interconnected computing devices,it is essential that service composition embraces an adaptive service provisioning *** learning has emerged as a powerful tool to compose and adapt Web services in open and dynamic ***,the most common applications of reinforcement learning algorithms are relatively inefficient in their use of the interaction experience data,whichmay affect the stability of the learning process when deployed to cloud *** particular,they make just one learning update for each interaction *** paper introduces a novel approach that aims to achieve greater data efficiency by saving the experience data and using it in aggregate to make updates to the learned *** proposed approach devises an offline learning scheme for cloud service composition where the online learning task is transformed into a series of supervised learning tasks.A set of algorithms is proposed under this scheme in order to facilitate and empower efficient service composition in the cloud under various policies and different *** results of our experiments show the effectiveness of the proposed approach for composing and adapting cloud services,especially under dynamic environment settings,compared to their online learning counterparts.

关键词： Service composition reinforcement learning cloud services offline learning

CTAB-assisted fabrication of hierarchical flower-like magnesium oxide adsorbent for enhanced removal performance towards phosphate

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2023年第9期11卷 3231-3240页

作者： Saeed ahmed State Key Laboratory of Chemical Resource Engineering College of ChemistryBeijing University of Chemical TechnologyBeijing 100029China Department of Chemistry The University of LahoreLahore 54590Pakistan Department of Chemistry University of ChakwalPakistan

In this work, a series of hierarchical flower-like magnesium oxide(MgO) adsorbents were successfully fabricated in a cetyltrimethylammonium bromide(CTAB) assisted solvothermal route using hexamethylenetetramine(HMTA) as a precipitating agent. Effects of CTAB feeding amount on the structure, morphology, pore structure, and corresponding adsorption behavior were investigated. The hierarchical gardenias flower-like MgO demonstrated a surface area of 336.54 m^(2)·g^(-1) at a minimum ratio of the CTAB/Mg^(2+)was 0.02 in the reaction system. The hierarchical MgO phosphate removal capacity was 348.32 mg·g^(-1), which followed the pseudo-second-order and Freundlich isotherm model obtained from the large surface area and appropriate pore size. The value of n also suggests the feasible nature of phosphate adsorption under the examined conditions. Indeed, this CTAB assisted solvothermal method can provide a new understanding to tune the desired properties of a material by merely adjusting the reaction parameters of MgO.

关键词： Adsorption CTAB-assisted Magnesium oxide Phosphate removal Solvothermal

Oxidation Properties in CO_2 of Inconel Alloy 600 Coated by Simultaneous Aluminizing-Chromizing Process

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2007年第2期20卷 134-139页

作者： ahmed Moosa Jalil Karim ahmed Ali Hoobi The University of Technology Baghdad-Iraq Ministry of Labor and Social Affairs Baghdad-Iraq Ministry of Science and Technology Baghdad-Iraq

IN 600 alloy was coated with two different types of coatings, Cr-modified aluminide coating this is called aluminizing-chromizing and Y-doped chromium modified aluminide coating this is called aluminizing-chromizing-yttriumizing. Diffusion coating was carried at 1 050℃ for 8 h under Ar atmosphere by simultaneous aluminizing-chromizing process and by simultaneous aluminizing-chromizing- yttriumizing. Cyclic oxidation tests were conducted on the uncoated and on the coated Inconel 600 alloy in the temperature range 800- 1 000℃ in CO2 for 100 h at 10 h *** results showed that the oxidation kinetics for uncoated Inconel 600 alloy in CO2 is parabolic and the phases present are NiO, （Fe, Cr）2O3 , NiFe2O4 and NiCrO4. The oxidation kinetics for both coated systems in CO2 was found to be parabolic and the value ofkp for both coated systems were found to be lower than that for uncoated Inconel 600 alloy. Oxide phases that formed on coated systems are Al2O3 and NiCrO4. The role of yttrium can be attributed to its ability to improve the adherence of the oxide scale.

关键词： Inconel oxidation diffusion bonding aluminizing-chromizing Ni-superalloy

Magnetoresistive properties of Ni-doped La_(0.7)Sr_(0.3)MnO_3 manganites

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2016年第7期35卷 551-558页

作者： ahmed Mohamed ahmed Abd El-Moez ahmed Mohamed Medhat Abdelrady Abdellateef Hassan ahmed Abd El-Ghanny Physics Department Faculty of ScienceSohag University

Lao.7Sr0.3Mnl_xNixO3 （x = 0, 0.025, 0.050 and 0.075） ceramics were prepared by the conventional solid-state reaction method. The partial substitution of Mn by Ni2＋ leads to a decrease in cell volume as well as a structural transition from the rhombohedral to the orthorhombic structure. Ni2＋ doping increases the electrical resistivity, decreases the semiconductor-metal transition temperature （Tms） and relatively enhances the room temperature magnetoresistance （MR）, especially in x = 0.025 and around Tins. With respect to conduction mechanism, the small polaron hopping （SPH） and the variable range hopping （VRH） models were used to ex- amine conduction in the semiconducting region.

关键词： Manganites X-ray diffraction Structure Electrical resistivity Magnetoresistance

Topological effects on non-relativistic eigenvalue solutions under AB-flux field with pseudoharmonic- and Mie-type potentials

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2023年第5期75卷 84-96页

作者： Faizuddin ahmed Department of Physics University of Science&Technology MeghalayaRi-BhoiMeghalaya-793101India

In this paper,we investigate the quantum dynamics of a non-relativistic particle confined by the Aharonov-Bohm quantum flux field with pseudoharmonic-type potential in the background of topological defect produced by a point-like global *** solve the radial Schrödinger equation analytically and determine the exact eigenvalue solution of the quantum ***,we consider a Mie-type potential in the quantum system and solve the radial equation analytically and obtain the eigenvalue *** analyze the effects of the topological defect and the quantum flux with these potentials on the energy eigenvalue and wave function of the nonrelativistic *** fact,it is shown that the energy levels and wave functions are influenced by the topological defect shifted the result compared to the flat space *** addition,the quantum flux field also shifted the eigenvalue solutions and an analogue of the Aharonov-Bohm effect for bound-states is ***,we utilize these eigenvalue solutions to some known diatomic molecular potential models and presented the energy eigenvalue and wave function.

关键词： topological defect non-relativistic wave equation physical potential geometric quantum phase special function solutions of wave equation:bound-state

Conservation Laws for Partially Conservative Variable Mass Systems via d＇Alembert＇s Principle

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2008年第9期25卷 3181-3184页

作者： AFTAB ahmed NASEER ahmed QUDRAT Khan Department of Mathematics Quaid-I-Azam University 45320 Islamabad 44000 Pakistan

Conservation laws for partially conservative variable mass dynamical systems under symmetric infinitesimal transformations are determined. A generalization of Lagrange-d ＇Alembert＇s principle for a variable mass system in terms of asynchronous virtual variation is presented. The generalized Killing equations are obtained such that their solution yields the transformations and the associated conservation laws. An example illusstrative of the theory is furnished at the end as well.

关键词： the power-law exponents precipitation durative abrupt precipitation change

Boundary layer flow of Maxwell fluid due to torsional motion of cylinder: modeling and simulation

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2020年第4期41卷 667-680页

作者： M.KHAN A.ahmed J.ahmed Department of Mathematics Quaid-i-Azam UniversityIslamabad 44000Pakistan Department of Basic Sciences University of Engineering and TechnologyTaxila 47050Pakistan

This paper investigates the boundary layer flow of the Maxwell fluid around a stretchable horizontal rotating cylinder under the influence of a transverse magnetic *** constitutive flow equations for the current physical problem are modeled and analyzed for the first time in the *** torsional motion of the cylinder is considered with the constant azimuthal velocity *** partial differential equations(PDEs)governing the torsional motion of the Maxwell fluid together with energy transport are simplified with the boundary layer *** current analysis is valid only for a certain range of the positive Reynolds ***,for very large Reynolds numbers,the flow becomes ***,the governing similarity equations are simplified through suitable transformations for the analysis of the large Reynolds *** numerical simulations for the flow,heat,and mass transport phenomena are carried out in view of the bvp4c scheme in *** outcomes reveal that the velocity decays exponentially faster and reduces for higher values of the Reynolds numbers and the flow penetrates shallower into the free stream *** is also noted that the phenomenon of stress relaxation,described by the Deborah number,causes to decline the flow fields and enhance the thermal and solutal energy transport during the fluid *** penetration depth decreases for the transport of heat and mass in the fluid with the higher Reynolds *** excellent validation of the numerical results is assured through tabular data with the existing literature.

关键词： torsional motion Maxwell fluid magnetic field stretchable rotating cylinder bvp4c scheme

Klein–Gordon oscillator with magnetic and quantum flux fields in non-trivial topological space-time

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2023年第2期75卷 89-97页

作者： Faizuddin ahmed Department of Physics University of Science&Technology MeghalayaRi-BhoiMeghalaya—793101India

The relativistic quantum motions of the oscillator field(via the Klein–Gordon oscillator equation)under a uniform magnetic field in a topologically non-trivial space-time geometry are *** solve the Klein–Gordon oscillator equation using the Nikiforov-Uvarov method and obtain the energy profile and the wave *** discuss the effects of the non-trivial topology and the magnetic field on the energy *** find that the energy eigenvalues depend on the quantum flux field that shows an analogue of the Aharonov–Bohm ***,we obtain the persistent currents,the magnetization,and the magnetic susceptibility at zero temperature in the quantum system defined in a state and show that these magnetic parameters are modified by various factors.

关键词： relativistic wave equations -solutions of wave equations:bound-state geometric quantum phases magnetic fields

Reviving the use of inhibitors of matrix metalloproteases in spinal cord injury:a case for specificity

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2023年第9期18卷 1925-1930页

作者： Zubair ahmed Neuroscience and Ophthalmology Institute of Inflammation and AgeingUniversity of BirminghamEdgbastonBirminghamUK Center for Trauma Sciences Research University of BimringhamEdgbastonBirminghamUK

At present,there are no resto rative therapies in the clinic for spinal cord injury,with current treatments offering only palliative treatment *** role of matrix metalloproteases is well established in spinal cord injury,howeve r,translation into the clinical space was plagued by early designs of matrix metalloprotease inhibitors that lacked specificity and fears of musculos keletal syndrome prevented their further *** r,much more specific matrix metalloprotease inhibitors have revived the possibility of using these inhibitors in the clinic since they are much more specific to their to rget matrix ***,the evidence for use of matrix metalloproteases after spinal cord injury is reviewed and researche rs are urged to overcome their old fears rega rding matrix metalloprotease inhibition and possible side effects for the field to *** published work by us shows that inhibition of specific matrix metalloproteases after spinal cord injury holds promise since four key consequences of spinal cord injury could be alleviated by specific,next-gene ration matrix metalloprotease *** example,specific inhibition of matrix metalloprotease-9 and matrix metalloprotease-12 within 24 hours after injury and for 3 days,alleviates spinal cord injury-induced edema,blood-s pinal co rd barrier breakdown,neuro pathic pain and resto res sensory and locomotor *** are now underway to translate this therapy into the clinic.

关键词： axon regeneration blood-spinal cord barrier edema functional recovery matrix metalloprotease-9 matrix metalloproteses-12 pain spinal cord injury