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Design of ultrafast all-optical PolsK DMUX based on semiconductor optical amplifiers

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Chinese Optics Letters 2012年第9期10卷 80-84页

作者： Hassan Kaatuzian hamed Ahmadi Photonics Research Lab Electrical Engineering Department Amirkabir University of Technology

A novel ultrahigh-speed all-optical demultiplexer （DMUX） with polarization-shift-keying （PolsK） modula- tion input signals is proposed. This design is based on four-wave mixing （FWM） in a semiconductor optical amplifier （sOA）. For analyzing each amplifier, we use finite-difference method （FDM） based on solution of the traveling wave coupled equations. Using numerical simulation, the all-optical DMUX is theoretically realized at 40 Gb/s. We also study the relation between optical confinement factor and thickness of active layer of the sOA section successfully, and investigate the increasing effect of confinement factor on the DMUX optical output power. With this work, the confinement factor is increased from 0.3 to 0.48, and as a result, the output power approximately twice of its initial value is achieved. Moreover, the effects of polarization dependence of sOA on the output performance of all-optical DMUX for PolsK signal are theoretically investigated in detail.

关键词： Design of ultrafast all-optical PolsK DMUX based on semiconductor optical amplifiers DMUX sOA

Assessment of converting approach to efficient design of micro-turboprop engines

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Chinese Journal of Aeronautics 2020年第2期33卷 572-588页

作者： hamed GOLCHIN Fathollah OMMI Zoheir sABOOHI Department of Mechanical Engineering Tarbiat Modares UniversityTehran 14115-111Iran Aerospace Research Institute(ARI) Ministry of ScienceResearchand TechnologyTehran 14115-111Iran

The design,manufacture and experiment of a shaft power unit for converting a microturbojet engine to a micro-turboprop in the class of less than 20 kW with the aim of obtaining maximum shaft power were described in this *** this purpose,a Wren 100 micro-turbojet engine was used as the gas generator,and the specifications of its outflow were *** optimal configuration of the inter-stage diffuser,which was an annular s-type diffuser,was selected based on its small total pressure drop and outlet flow *** power turbine was a single stage axial turbine that was designed based on the fixed nozzle angle assumption without any taper or twist in its *** turbine rotor was a bladed disk(Blisk)in which its unique blade profiles were designed based on the Wilson ***,the shaft power unit was completed by designing and manufacturing an exhaust complex and ***,the micro-turboprop engine was tested with an overloading *** results show a significant increase in the extracted power,an acceptable efficiency of the power turbine,and a significant reduction in the specific Fuel Consumption(sFC)compared to other engines that use similar gas generators.

关键词： Axial turbine Blisk Gas generators Micro-turboprop Power unit

Towards automated statistical partial discharge source classification using pattern recognition techniques

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High Voltage 2018年第3期3卷 162-169页

作者： hamed Janani Behzad Kordi Department of Electrical and Computer Engineering University of Manitoba75A Chancellor's CircleWinnipegMBCanadaR3T5V6 Powertech Labs Inc. 12388-88 AvenueSurreyBCCanadaV3W 7R7

This study presents a comprehensive review of the automated classification in partial discharge(PD)source identification and probabilistic interpretation of the classification results based on the relationship between the variation of the phase-resolved PD(PRPD)patterns and the source of the *** proposed automated classification system consists of modern,high-performance statistical feature extraction methods and classifier *** application in online monitoring and recognition of the PD patterns is investigated based on their low-processing time and high-performance *** application of modern statistical algorithms and pre-processing methods configured in this automated classification system improves the pattern recognition accuracy of the different PD sources that are suitable to be employed in different high-voltage(HV)insulation *** evaluate the performance of the different combinations of the feature extraction/classier pairs,laboratory setups are designed and built that simulate various types of *** test cells include three sources of PD in sF6,two sources of PD in transformer oil,and corona in the *** samples for different classes of PD sources are captured under two levels of voltage and two different levels of *** results of this study evaluate the suitability of the proposed classification systems for probabilistic source identification in various insulation ***,of importance to the problem of the PD source identification is to assign a‘degree of membership’to each PRPD pattern,besides assigning a class label to *** of the classifier algorithms studied in this study,such as fuzzy classifiers,are not only able to show high classification accuracy rate,but they also calculate the‘degree of membership’of a sample to a class of *** enables probabilistic interpretation of a new PRPD pattern that is being *** determination of the degree of membership for future PRPD samples allows saf

关键词： pattern membership source

Cardiac stem cells: Current knowledge and future prospects

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World Journal of stem Cells 2022年第1期14卷 1-40页

作者： Radwa A Mehanna Marwa M Essawy Mona A Barkat Ashraf K Awaad Eman H Thabet Heba A hamed Hagar Elkafrawy Nehal A Khalil Abeer sallam Marwa A Kholief samar s Ibrahim Ghada M Mourad Medical Physiology Department/Center of Excellence for Research in Regenerative Medicine and Applications Faculty of MedicineAlexandria UniversityAlexandria 21500Egypt Oral Pathology Department Faculty of Dentistry/Center of Excellence for Research in Regenerative Medicine and ApplicationsFaculty of MedicineAlexandria UniversityAlexandria 21500Egypt Human Anatomy and Embryology Department/Center of Excellence for Research in Regenerative Medicine and Applications Faculty of MedicineAlexandria UniversityAlexandria 21500Egypt Center of Excellence for Research in Regenerative Medicine and Applications Faculty of MedicineAlexandria UniversityAlexandria 21500Egypt Histology and Cell Biology Department/Center of Excellence for Research in Regenerative Medicine and Applications Faculty of MedicineAlexandria UniversityAlexandria 21500Egypt Medical Biochemistry Department/Center of Excellence for Research in Regenerative Medicine and Applications Faculty of MedicineAlexandria UniversityAlexandria 21500Egypt Forensic Medicine and Clinical toxicology Department/Center of Excellence for Research in Regenerative Medicine and Applications Faculty of MedicineAlexandria UniversityAlexandria 21500Egypt

Regenerative medicine is the field concerned with the repair and restoration of the integrity of damaged human tissues as well as whole *** the inception of the field several decades ago,regenerative medicine therapies,namely stem cells,have received significant attention in preclinical studies and clinical *** from their known potential for differentiation into the various body cells,stem cells enhance the organ's intrinsic regenerative capacity by altering its environment,whether by exogenous injection or introducing their products that modulate endogenous stem cell function and fate for the sake of ***,research in cardiology has highlighted the evidence for the existence of cardiac stem and progenitor cells(CsCs/CPCs).The global burden of cardiovascular diseases’morbidity and mortality has demanded an in-depth understanding of the biology of CsCs/CPCs aiming at improving the outcome for an innovative therapeutic *** review will discuss the nature of each of the CsCs/CPCs,their environment,their interplay with other cells,and their *** addition,important issues are tackled concerning the potency of CsCs/CPCs in relation to their secretome for mediating the ability to influence other ***,the review will throw the light on the clinical trials and the preclinical studies using CsCs/CPCs and combined therapy for cardiac ***,the novel role of nanotechnology in cardiac regeneration will be explored.

关键词： Cardiac stem and progenitor cells Cardiac stem cells’secretome Cardiac stem cells’niche and metabolism Nanotechnology Clinical trials Combined therapy

solute mixing in a permeable non-rectangular channel

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International Journal of sediment Research 2020年第2期35卷 134-145页

作者： sonia Zebardast sayyed-Hassan tabatabaei Fariborz Abbasi Manuchehr Heidarpour Department of Water Engineering Faculty of AgricultureShahrekord University Agricultural Engineering Research Institute (AERI) Agricultural ResearchEducation and Extension Organization (AREEO) 3. Department of Water EngineeringCollege of AgricultureIsfahan University of Technology

Understanding diffusion and solute transport,is regarded as a main activity in environmental management,sustainable development and sedimentation processes because of their role in diffusion of *** current paper presents an experimental study which was done in a parabolic channel with permeable and impermeable bed conditions in order to estimate the transverse mixing coefficient(TMC) and the maximum solute mixing length(sML) for different channel bed roughness coefficients and *** cross section of the channel was 0.5 m wide and 0.3 m deep with a parabolic shape(*** to furrow irrigation).Three levels of bed roughness coefficient of 0.02,0.04,and 0.06,and three discharges of 5,10,and 15 L/s were *** infiltration channel was applied at a low level and medium level as well as a case without *** the current experiments,sodium chloride was used as a soluble tracer and was injected into the water at mid depth in the upstream cross *** tracer concentration profile in the water and velocity profile were measured at eight cross sections in the *** results showed that the values of sML ranged between 20 and 46 m in impermeable and permeable beds channel beds *** assessment of usual discharge values,infiltration,and roughness coefficient of a furrow(agricultural field) indicated that the sML of the furrows were less than20 *** the current research,the average dimensionless mixing coefficient was found to be 0.17 in the nonrectangular ***,equations were developed to explain the TMC and sML in a permeable parabolic channel that could be beneficial in prediction of fertilizer transport in furrow irrigatio n.

关键词： Environmental hydraulics Fertigation Furrow irrigation solute mixing length Transverse mixing coefficient

Fabrication method and microstructural characteristics of coal-tar-pitchbased 2D carbon/carbon composites

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International Journal of Minerals,Metallurgy and Materials 2015年第2期22卷 210-216页

作者： Mohammad Esmaeeli hamed Khosravi Alireza Mirhabibi school of Metallurgy and Materials Engineering Iran University of Science and Technology Faculty of Materials science and Engineering K. N. Toosi University of Technology

The lignin-cellulosic texture of wood was used to produce two-dimensional （2D） carbon/carbon （C/C） composites using coal tar pitch. Ash content tests were conducted to select two samples among the different kinds of woods present in lran, including walnut, white poplar, cherry, willow, buttonwood, apricots, berry, and blue wood. Walnut and white poplar with ash contents of 1.994wt% and 0.35 lwt%, respectively, were selected. The behavior of these woods during pyrolysis was investigated by differential thermal analysis （DTA） and thermo gravimetric （TG） analysis. The bulk density and open porosity were measured after carbonization and densification. The mierostruc- tural characteristics of samples were investigated by scanning electron microscopy （sEM）, X-ray diffraction （XRD）, and Fourier-transform infrared （FT-IR） spectroscopy. The results indicate that the density of both the walnut and white poplar is increased, and the open porosity is decreased with the increasing number of carbonization cycles. The XRD patterns of the wood charcoal change gradually with increasing py- rolysis temperature, possibly as a result of the ultra-structural changes in the charcoal or the presence of carbonized coal tar pitch in the composite＇s body.

关键词： carbon/carbon composites microstructure porosity density densification carbonization

Modal interactions in primary and subharmonic resonant dynamics of imperfect microplates with geometric nonlinearities

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Acta Mechanica sinica 2016年第3期32卷 469-480页

作者： hamed Farokhi Mergen H.Ghayesh Department of Mechanical Engineering McGill University school of Mechanical Materials and MechatronicEngineering University of Wollongong

This paper analyses the modal interactions in the nonlinear, size-dependent dynamics of geometrically imperfect microplates. Based on the modified couple stress theory,the equations of motion for the in-plane and out-of-plane motions are obtained employing the von Kármán plate theory as well as Kirchhoff＇s hypotheses by means of the Lagrange equations. The equations of motions are solved using the pseudo-arclength continuation technique and direct timeintegration method. The system parameters are tuned to the values associated with modal interactions, and then nonlinear resonant responses and energy transfer are *** motion characteristics are shown in the form of frequency-response and force-response curves, time histories, phase-plane portraits, and fast Fourier transforms.

关键词： Modal interactions Microplate sizedependent dynamics Modified couple stress theory stability

Introducing a proper hydrogen liquefaction concept for using wasted heat of thermal power plants-case study: Parand gas power plant

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Chinese Journal of Chemical Engineering 2021年第12期34卷 187-196页

作者： hamed Rezaie Azizabadi Masoud Ziabasharhagh Mostafa Mafi Faculty of Mechanical Engineering K.N.Toosi University of TechnologyTehranIran Department of Mechanical Engineering Imam Khomeini International UniversityQazvinIran

A hydrogen liquefaction concept with an innovative configuration and a capacity of 4 kg·s^(-1)(345.6 t·d^(-1))is *** concept involves an ammonia absorption refrigeration system for the pre-cooling of hydrogen and MR streams from 25℃ to-30℃.The ammonia absorption refrigeration system is fed by exhaust gases of the Pa rand gas power plant that are normally dissipated to the environment with a temperature of 546℃.The simulation is performed by Aspen HYsYs V9.0,using two separate equations of state for simulating hydrogen and MR streams to gain more accurate results especially for ortho-para *** show that conversion enthalpy estimated by Aspen HYsYs,fits very well to the experimental *** the important independent variables and composition of MRs are done using trial and error procedure,a functional and straightforward method for complicated *** minimum temperature limit in the cooling section is lowered,and an ortho-para converter is implemented in this *** proposed concept performs well from energy aspects and leads to COP and sEC equal to 0.271 and 4.54 kW·h·kg^(-1),*** main advantage of this study is in the low sEC,eliminating the losses of the distribution network,and improving the ability of the hydrogen liquefaction for energy storage in off-peak times.

关键词： Hydrogen Liquefaction Absorption refrigeration Waste treatment Mixed-refrigerant Ortho-para conversion

镍铝化物增强摩擦堆焊Al-Cu-Mg合金基复合涂层的非等温时效行为

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Journal of Central south University 2023年第11期30卷 3696-3708页

作者： Ramezanali FARAJOLLAHI hamed JAMsHIDI AVAL Roohollah JAMAATI Mousa JAVIDANI Department of Materials Engineering Babol Noshirvani University of TechnologyShariati AvenueBabol47148-71167Iran Department of Applied science University of Québec at ChicoutimiSaguenayQC G7H 2B1Canada

本文研究了镍铝化物对Al-Cu-Mg合金非等温时效行为的影响。对经非等温时效处理的含镍铝化物Al-Cu-Mg合金的组织、力学性能和耐蚀性进行了评价。结果表明,在Al-Cu-Mg基体中加入1.5 wt%Ni后,Al-Cu-Mg基体中镍铝化物的存在使析出物由s-Al_(... 详细信息

本文研究了镍铝化物对Al-Cu-Mg合金非等温时效行为的影响。对经非等温时效处理的含镍铝化物Al-Cu-Mg合金的组织、力学性能和耐蚀性进行了评价。结果表明,在Al-Cu-Mg基体中加入1.5 wt%Ni后,Al-Cu-Mg基体中镍铝化物的存在使析出物由s-Al_(2)CuMg转变为θ-Al_(2)Cu。在非等温时效过程中,达到最大力学性能的非等温时效处理温度由250℃转变为300℃。与170℃等温人工时效处理相比,经非等温时效处理的含镍铝化物Al-Cu-Mg合金的最大硬度和力学性能均提高了9%。含镍铝化物试样在300℃时达到最大硬度和抗剪强度,分别为HV0.1(143.4±6.4)和(298.6±9.6)MPa。非等温时效处理后,与AA2024铝合金基体和不含镍铝化物涂层相比,含镍涂层的腐蚀电流强度分别降低了约58%和49%。与传统的人工时效处理相比,经非等温时效处理的含镍铝涂层的腐蚀电流降低了16.7%。

关键词：非等温时效镍添加剂摩擦堆焊微观结构腐蚀行为