检索结果-南通市图书馆

Kinetic study of methane hydrate formation in the presence of carbon nanostructures

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2019年第3期16卷 657-668页

作者： Saeid abedi-Farizhendi Mina Iranshahi Abolfazl Mohammadi Mehrdad Manteghian Amir H. Mohammadi Faculty of Chemical Engineering Tarbiat Modares University Tehran Iran Department of Petroleum Engineering South Tehran Branch Islamic Azad University Tehran Iran Department of Chemical Engineering University of Bojnord Bojnord Iran Institut de Recherche en Genie Chimique et Petrolier (IRGCP) Paris Cedex France Discipline of Chemical Engineering School of Engineering University of KwaZulu-Natal Howard College Campus King George V Avenue Durban 4041 South Africa

The effect of synthesized nanostructures,including graphene oxide,chemically reduced graphene oxide with sodium dodecyl sulfate(SDS),chemically reduced graphene oxide with polyvinylpyrrolidone,and multi-walled carbon nanotubes,on the kinetics of methane hydrate formation was investigated in this *** experiments were carried out at a pressure of 4.5 MPa and a temperature of 0 ℃ in a batch *** adding nanostructures,the induction time decreases,and the shortest induction time appeares at certain concentrations of reduced graphene oxide with SDS and graphene oxide,that is,at a concentration of 360 ppm for reduced graphene oxide with SDS and 180 ppm for graphene oxide,with a 98% decrease in induction time compared to that in pure ***,utilization of carbon nanostructures increases the amount and the rate of methane consumed during the hydrate formation *** of multi-walled carbon nanotubes with a concentration of 90 ppm showes the highest amount of methane *** amount of methane consumption increases by 173% in comparison with that in pure *** addition of carbon nanostructures does not change the storage capacity of methane hydrate in the hydrate formation process,while the percentage of water conversion to hydrate in the presence of carbon nanotubes increases considerably,the greatest value of which occurres at a 90 ppm concentration of carbon nanotubes,that is,a 253% increase in the presence of carbon nanotubes compared to that of pure water.

关键词： Clathrate hydrate Kinetics Carbon nanostructures Graphene oxide SDS PVP

Elastic Mechanical Stress Analysis in a 2D-FGM Thick Finite Length Hollow Cylinder with Newly Developed Material Model

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 2016年第2期29卷 178-191页

作者： Amir Najibi Mohammad hassan Shojaeefard Faculty of Mechanical Engineering Semnan University School of Mechanical Engineering Iran University of Science & Technology

In this paper a new 2D-FGM material model based on Mori-Tanaka scheme and third-order transition function has been developed for a thick hollow cylinder of finite *** mechanical stress analysis is performed by utilizing the finite element *** corresponding material,displacement and stress distributions are evaluated for different values of nr and ***,the effects of different material property distributions on the effective stress with respect to the metallic phase volume fraction are *** is demonstrated that the increase in nr and V_m leads to a significant reduction in the effective ***,it is shown that the ceramic phase rich cylinder wall has lower maximum effective stresses of which the lowest value of effective stress has been evaluated for nr=20 and nz=*** minimum value is about half the maximum effective stress which has been evaluated for the non-FGM cylinder case（nr=nz=0.1）.

关键词： 2D-FGM elastic analysis thick hollow cylinder Mori-Tanaka material model

Influences of the fluidizing and spouting pulsation on particle motion in spout-fluid beds

在线全文

学校读者我要写书评

暂无评论

Particuology 2018年第1期16卷 139-148页

作者： Maysam Saidi hassan Basirat Tabrizi Department of Mechanical Engineering Faculty of Engineering Razi University Kermanshah lran Department of Mechanical Engineering Amirkabir University of Technology Tehran lran

Effects of variable airflow on particle motion in spout-fluid beds are studied. Computational fluid dynam- ics using Navier-Stokes equations for the gas phase coupled with the discrete element method using Newton＇s laws for the solid phase have been employed. Results indicate that increasing the fluidizing velocity diminishes dead zones and increases both the total height of the bed and the traversed distance by particles in the steady spout-fluid bed. In pulsed airfows, two configurations are investigated, namely, the spouted pulsed-fluidized bed with pulsed flow of the fluidizing velocity, and the pulsed-spouted flu- idized bed with pulsed flow of the spouting velocity. The positive effect of pulsation on particle motion is shown and the effects of parameters, such as amplitude and frequency, on the dynamics of the bed are investigated in each configuration. An increase of up to 19% in traversed distance is found for the range studied, which suggests flow pulsation as a promising technique for increasing particle mixing in spout-fluid beds.

关键词： Computational fluid dynamics Discrete element method Flow pulsation Gas-solid Particle Spout-fluid bed

HEAT-RESISTANT,PYRIDINE-BASED POLYAMIDES CONTAINING ETHER AND ESTER UNITS WITH IMPROVED SOLUBILITY

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

Chinese Journal of Polymer Science 2010年第1期28卷 29-37页

作者： hassan Ebadi Shahram Mehdipour-Ataei Islamic Azad University of Shahreza P.O.Box 81145-311 ShahrezaIsfahanIran Iran Polymer and Petrochemical Institute P.O.Box 14965/115 TehranIran

A diamine containing ether and ester units, as basic monomer for the preparation of polyamides, was prepared via three consecutive reactions. Nucleophilic substitution reaction of 1,4-dihydroxy benzene with 4-nitrobenzoyl chloride produced 4-hydroxyphenyl 4-nitrobenzoate （HPNB）. Reduction of nitro groups to amino groups using Fe and HC1 resulted in preparation of 4-hydroxyphenyl 4-aminobenzoate （HPAB）. The diamine was synthesized through nucleophilic substitution reaction of HPAB with 2,6-dichloropyridine. The precursors and diamine were fully characterized by common methods, and the diamine was polycondensed with different diacid chlorides in the presence of an acid scavenger to prepare new polyamides. The polyamides were characterized, and their physical properties including thermal stability and behavior, inherent viscosity and solubility were studied.

关键词： Polyamide Polycondensation Diamine Ester Ether.

Nonsingular terminal sliding mode approach applied to synchronize chaotic systems with unknown parameters and nonlinear inputs

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2012年第6期21卷 107-116页

作者： Mohammad Pourmahmood Aghababa hassan Feizi Electrical Engineering Department Urmia University of TechnologyUrmiaIran Department of Mathematics Mamaghan BranchIslamic Azad UniversityMamaghanIran

This paper deals with the design of a novel nonsingular terminal sliding mode controller for finite-time synchro-nization of two different chaotic systems with fully unknown parameters and nonlinear inputs. We propose a novel nonsingular terminal sliding surface and prove its finite-time convergence to zero. We assume that both the master＇s and the slave＇s system parameters are unknown in advance. Proper adaptation laws are derived to tackle the unknown parameters. An adaptive sliding mode control law is designed to ensure the existence of the sliding mode in finite time. We prove that both reaching and sliding mode phases are stable in finite time. An estimation of convergence time is given. Two illustrative examples show the effectiveness and usefulness of the proposed technique. It is worthwhile noticing that the introduced nonsingular terminal sliding mode can be applied to a wide variety of nonlinear control problems.

关键词： nonsingular terminal sliding mode finite-time synchronization uncertain parameter,nonlinear input

Mass and performance optimization of an airplane wing leading edge structure against bird strike using Taguchi-based grey relational analysis

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2016年第4期29卷 934-944页

作者： hassan Pahange Mohammad Hossein Abolbashari Department of Mechanical Engineering Ferdowsi University of Mashhad Department of Mechanical Engineering Lean Production Engineering Research Center Ferdowsi University of Mashhad

Collisions between birds and aircraft are one of the most dangerous threats to flight safety. In this study, smoothed particles hydrodynamics(SPH) method is used for simulating the bird strike to an airplane wing leading edge structure. In order to verify the model, first, experiment of bird strike to a flat aluminum plate is simulated, and then bird impact on an airplane wing leading edge structure is investigated. After that, considering dimensions of wing internal structural components like ribs, skin and spar as design variables, we try to minimize structural mass and wing skin deformation simultaneously. To do this, bird strike simulations to 18 different wing structures are made based on Taguchi’s L18 factorial design of experiment. Then grey relational analysis is used to minimize structural mass and wing skin deformation due to the bird strike. The analysis of variance(ANOVA) is also applied and it is concluded that the most significant parameter for the performance of wing structure against impact is the skin thickness. Finally, a validation simulation is conducted under the optimal condition to show the improvement of performance of the wing structure.

关键词： Bird strike Grey relational analysis Multi-objective optimization Smooth particle hydrody namics(SPH) Wing leading edge structure

Strategic Bidding in Distribution Network Electricity Market Focusing on Competition Modeling and Uncertainties

在线全文

学校读者我要写书评

暂无评论

Journal of Modern Power Systems and Clean Energy 2021年第3期9卷 561-572页

作者： Mehrdad Mallaki Mehdi S.Naderi Mehrdad abedi Saeed D.Manshadi Gevork B.Gharehpetian the Electrical Engineering Department Amirkabir University of TechnologyTehranIran Iran Grid Secure Operation Research Centre Amirkabir University of TechnologyTehranIran theDepartment of Electrical and Computer Engineering San Diego State UniversitySan DiegoUSA

Developing the electricity market at the distribution level can facilitate the energy transactions in distribution networks with a high penetration level of distributed energy resources(DERs)and microgrids(MGs).However,the lack of comprehensive information about the marginal production cost of competitors leads to uncertainties in the optimal bidding strategy of *** electricity demand within the network and the price in the wholesale electricity market are two other sources of the *** this paper,a day-ahead-market-based framework for managing the energy transactions among MGs and other participants in distribution networks is introduced.A game-theory-based method is presented to model the competition and determine the optimal bidding strategy of participants in the *** optimization technique is employed to capture the uncertainties in the marginal cost of ***,the uncertainties in demand are modeled using a scenario-based stochastic *** results ob-tained from case studies reveal the merit of considering competition modeling and uncertainties.

关键词： Competition modeling bidding strategy distribution network electricity market microgrid uncertainty robust optimization

InGaN/GaN laser diode characterization and quantum well number effect

在线全文

学校读者我要写书评

暂无评论

Chinese Optics Letters 2009年第3期7卷 226-230页

作者： S.M.Thahab H.Abu hassan Z.hassan Nano-Optoelectronics Research and Technology Laboratory School of PhysicsUniversiti Sains Malaysia

The effect of quantum well number on the quantum efficiency and temperature characteristics of In- GaN/GaN laser diodes （LDs） is determined and investigated. The 3-nm-thick In0.13Ca0.87N wells and two 6-am-thick GaN barriers are selected as an active region for Fabry-Perot （FP） cavity waveguide edge emitting LD. The internal quantum efficiency and internal optical loss coefficient are extracted through the simulation software for single, double, and triple InGaN/GaN quantum wells. The effects of device temperature on the laser threshold current, external differential quantum efficiency （DQE）, and output wavelength are also investigated. The external quantum efficiency and characteristic temperature are improved significantly when the quantum well number is two. It is indicated that the laser structures with many quantum wells will suffer from the inhomogeneity of the carrier density within the quantum well itself which affects the LD performance.

关键词： Computer software Efficiency Fabry Perot interferometers Quantum well lasers Semiconductor lasers Semiconductor quantum wells

N^1,N^2-Bis[1-(2-hydroxyphenyl)methylidene]ethanedihydrazide as a neutral ionophore for preparation of a new Ho^(3+) PVC-membrane sensor

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2011年第6期22卷 701-704页

作者： hassan Ali Zamani Department of Applied Chemistry Quchan branch Islamic Azad University

N^1,N^2-Bis[1-（2-hydroxyphenyl）methylidene]ethanedihydrazide（MEH） was used as new compound which plays the role of an excellent ion carrier in the fabrication of a Ho（Ⅲ） membrane *** electrode shows a good selectivity for Ho（Ⅲ） ion with respect to most common cations including alkali,alkaline earth,transition and heavy metal *** electrode has a wide linear dynamic range from 1.0×10^（-6） to 1.0×10^（-2） mol/L with a Nernstian slope of 19.8±0.3 mV per decade and a low detection limit of 5.8×10^（-7） mol/L in the pH range of 2.5-9.8,while the response time was rapid（10 s）.The suggested sensor was applied to the determination of Ho（Ⅲ） ions in tap water and river water samples.

关键词： Ion-selective electrode Potentiometry Sensor PVC membrane