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Effect of heat input on microstructure and mechanical properties of dissimilar joints of AISI 316L steel and API X70 high-strength low-alloy steel

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Journal of Iron and Steel Research International 2017年第12期24卷 1248-1253页

作者： Ebrahim Mortazavi reza amini Najafabadi Amirhossein Meysami Metallurgy&Materials Department Golpayegan University of TechnologyGolpayegan 65651Iran

The microstructure and mechanical properties of dissimilar joints of AISI 316L austenitic stainless steel and API X70 high-strength low-alloy steel were *** this purpose,gas tungsten arc welding（GTAW）was used in three different heat inputs,including 0.73,0.84,and 0.97 kJ/*** microstructural investigations of different zones including base metals,weld metal,heat-affected zones and interfaces were performed by optical microscopy and scanning electron *** mechanical properties were measured by microhardness,tensile and impact *** was found that with increasing heat input,the dendrite size and inter-dendritic spacing in the weld metal ***,the amount of delta ferrite in the weld metal was ***,tensile strength and hardness were reduced and impact test energy was *** investigation of the interface between AISI 316L base metal and ER316L filler metal showed that increasing the heat input increases the size of austenite grains in the fusion boundary.A transition region was formed at the interface between API X70 steel and filler metals.

关键词： Dissimilar joint AISI 316L steel API X70 high-strength low-alloy steel Transition region Heat input

Internal Short Circuit Detection for Parallel-Connected Battery Cells Using Convolutional Neural Network

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Automotive Innovation 2022年第2期5卷 107-120页

作者： Niankai Yang Ziyou Song Mohammad reza amini Heath Hofmann Department of Naval Architecture and Marine Engineering University of MichiganAnn ArborMI 48109USA Department of Mechanical Engineering National University of SingaporeSingapore 117575Singapore Department of Electrical Engineering and Computer Science University of MichiganAnn ArborMI 48109USA

Reliable and timely detection of an internal short circuit(ISC)in lithium-ion batteries is important to ensure safe and efficient *** paper investigates ISC detection of parallel-connected battery cells by considering cell non-uniformity and sensor limitation(i.e.,no independent current sensors for individual cells in a parallel string).To characterize ISC-related signatures in battery string responses,an electro-thermal model of parallel-connected battery cells is first established that explicitly captures *** analyzing the data generated from the electro-thermal model,the distribution of surface tem-perature among individual cells within the battery string is identified as an indicator for ISC detection under the constraints of sensor limitations.A convolutional neural network(CNN)is then designed to estimate the ISC resistance by using the cell surface temperature and the total capacity of the string as *** on the estimated ISC resistance from CNN,the strings are classified as faulty or non-faulty to guide the examination or replacement of the *** algorithm is evaluated in the presence of signal noises in terms of accuracy,false alarm rate,and missed detection rate,verifying the effectiveness and robustness of the proposed approach.

关键词： Internal short circuit Parallel-connected battery cells Convolutional neural network Cell temperature distribution

Improvement of Surface Mechanical and Tribological Characteristics of L-PBF Processed Commercially Pure Titanium through Ultrasonic Impact Treatment

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Acta Metallurgica Sinica(English Letters) 2024年第6期37卷 1034-1046页

作者： Iman Ansarian reza Taghiabadi Saeid amini Mohammad Hossein Mosallanejad Luca Iuliano Abdollah Saboori Department of Materials Science and Metallurgy Imam Khomeini International University(IKIU)QazvinIran Department of Mechanical Engineering University of KashanKashanIran Integrated Additive Manufacturing Center Department of Management and Production EngineeringPolitecnico di TorinoCorso Duca Degli Abruzzi 2410129TurinItaly

Multi-pass ultrasonic impact treatment(UIT)was applied to modify the microstructure and improve the mechanical and tribological characteristics at the near-surface region of commercially pure Ti(CP-Ti)specimens produced by the laser powder bed fusion(L-PBF)*** considerably refined the L-PBF process-related acicular martensites(α′-M)and produced a well-homogenized and dense surface microstructure,where the porosity content of 1-,3-,and 5-pass UITed samples was reduced by 43,60,and 67%,*** UITed samples showed an enhancement in their near-surface mechanical properties up to a depth of about 300μ*** nanoindentation results for the 3-pass UITed sample revealed an increase of about 53,45,and 220%in its nanohardness,H/E_(r),and H_(3)/E_(r)^(2)indices,*** stylus profilometry results showed that performing the UIT removed the L-PBF-related features/defects and offered a smooth *** roughness average(R_(a))and the skewness(R_(sk))of the 3-pass UITed sample were found to be lower than those of the L-PBFed sample by 95 and 223%,*** the UIT also enhanced the material ratio,where the maximum load-bearing capacity(~100%)in as-L-PBFed(as-built)and 3-pass UITed samples was obtained at 60-and 10-µm depths,*** tribological investigations showed that applying the UIT resulted in a significant reduction of wear rate and average coefficient of friction(COF)of *** instance,under the normal pressures of 0.05 and 0.2 MPa,the wear rate and COF of the 3-pass UITed sample were lower than those of the L-PBFed sample by 65 and 58%,and 20 and 17%,respectively.

关键词： Laser powder bed fusion Ultrasonic impact treatment Commercially pure Ti(CP-Ti) Surface mechanical properties Tribological properties

Applying DNA Computation to Error Detection Problem in Rule-Based Systems

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Journal of Intelligent Learning Systems and Applications 2015年第1期7卷 21-36页

作者： Behrouz Madahian Amin Salighehdar reza amini Department of Mathematical Sciences University of Memphis Memphis USA Financial Engineering Department Stevens Institute of Technology Hoboken USA Department of Computer Science Florida International University Miami USA

As rule-based systems (RBS) technology gains wider acceptance, the need to create and maintain large knowledge bases will assume greater importance. Demonstrating a rule base to be free from error remains one of the obstacles to the adoption of this technology. In the past several years, a vast body of research has been carried out in developing various graphical techniques such as utilizing Petri Nets to analyze structural errors in rule-based systems, which utilize propositional logic. Four typical errors in rule-based systems are redundancy, circularity, incompleteness, and inconsistency. Recently, a DNA-based computing approach to detect these errors has been proposed. That paper presents algorithms which are able to detect structural errors just for special cases. For a rule base, which contains multiple starting nodes and goal nodes, structural errors are not removed correctly by utilizing the algorithms proposed in that paper and algorithms lack generality. In this study algorithms mainly based on Adleman’s operations, which are able to detect structural errors, in any form that they may arise in rule base, are presented. The potential of applying our algorithm is auspicious giving the operational time complexity of O(n*(Max{q, K, z})), in which n is the number of fact clauses;q is the number of rules in the longest inference chain;K is the number of tubes containing antecedents which are comprised of distinct number of starting nodes;and z denotes the maximum number of distinct antecedents comprised of the same number of starting nodes.

关键词： DNA Computing Rule-Based Systems Rule Verification Structural Errors

Potentiodynamical Research of Zn-Al-Mg Alloy System in the Neutral Ambience of NaCl Electrolyte and Influence of Mg on the Structure

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Journal of Surface Engineered Materials and Advanced Technology 2012年第2期2卷 110-114页

作者： reza amini Ziadolla Obidov Izatulla Ganiev Mohammad Razazi Department of Material Science and Engineering Islamic Azad University Isfahan Iran Tajikistan Academy of Sciences Chemistry Institute Dushanbe Tajikistan.

The results of anodic behavior of Zn5Al, Zn55Al alloys alloyed with Magnesium in the environment and their micro-structures are studied. A potentiodynamical research carried out by Zinc-Aluminum alloys, alloyed with Magnesium obtained a corrosion-resistant coating with optimum concentration of Magnesium about 0.005 - 0.1wt%. The rate of corrosion of these alloys is 2 - 2.5 times lower than Zn5Al, Zn55Al initial alloys. It is explained by the effect of modification on the structure of original alloys and they can be used as an anticorrosion coating for protecting corrosion of steel frames.

关键词： Zn5Al Zn55Al Magnesium NaCl Electrolyte Corrosion Resistant

Anodic Behavior of Zn-Al-Be Alloys in NaCl Solution and the Influence of Be on Structure

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Journal of Surface Engineered Materials and Advanced Technology 2012年第2期2卷 127-131页

Potentiodynamic results of anodic behavior of Zn5Al and Zn55Al alloys, alloyed with Beryllium in the ambience of NaCl electrolyte and their microstructures are studied. They showed that a small addition of Beryllium (0.005 - 0.05 wt%) improves the corrosion resistance of Zn5Al and Zn55Al original alloys to 2 - 3 times by changing grains shape to spherical and changing sizes to small grains. The proposed composition of Zinc-Aluminum alloy, which contains of Beryllium, can be used as anodic coatings to protect steel products and constructions against corrosion.

关键词： Zn5Al Zn55Al Beryllium NaCl Solution Corrosion Resistant

Nonlinear phenomena in vibrations of embedded carbon nanotubes conveying viscous fluid

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Nanotechnology and Precision Engineering 2024年第1期7卷 44-54页

作者： reza Ebrahimi Mechanical Engineering Faculty of EngineeringYasouj UniversityYasouj 75918-74831Iran

Various nonlinear phenomena such as bifurcations and chaos in the responses of carbon nanotubes(CNTs)are recognized as being major contributors to the inaccuracy and instability of nanoscale mechanical ***,the main purpose of this paper is to predict the nonlinear dynamic behavior of a CNT conveying viscousﬂuid and supported on a nonlinear elastic *** proposed model is based on nonlocal Euler–Bernoulli beam *** Galerkin method and perturbation analysis are used to discretize the partial differential equation of motion and obtain the frequency-response equation,respectively.A detailed parametric study is reported into how the nonlocal parameter,foundation coefﬁcients,ﬂuid viscosity,and amplitude and frequency of the external force inﬂuence the nonlinear dynamics of the ***,quasi-periodic,and chaotic behaviors and hardening nonlinearity are revealed by means of the vibration time histories,frequency-response curves,bifurcation diagrams,phase portraits,power spectra,and Poincaré***,the results show that it is possible to eliminate irregular motion in the whole range of external force amplitude by selecting appropriate parameters.

关键词： Nonlinear vibration Carbon nanotubes Nonlocal effect Viscousﬂuid Nonlinear elastic medium

Resilence Control of DC Microgrid Integrated with Multi-Nanogrids Considering Connected-Islanded States

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CSEE Journal of Power and Energy Systems 2024年第2期10卷 786-796页

作者： Hossien Faraji reza Hemmati Pierluigi Siano Department of Electrical Engineering Amirkabir University of TechnologyTehranIran Department of Electrical Engineering Kermanshah University of TechnologyKermanshahIran Department of Management&Innovation Systems University of Salernoand also with the Department of Electrical and Electronic Engineering ScienceUniversity of JohannesburgJohannesburg 2006South Africa

In this paper, a DC microgrid (DCMG) integrated with a set of nano-grids (NG) is studied. DCMG exchanges predetermined active and reactive power with the upstream network. DCMG and NGs are coordinately controlled and managed in such a way the exchanged P-Q power with external grid are kept on scheduled level following all events and operating conditions. The proposed control system, in addition to the ability of mutual support between DCMG and NGs, makes NGs support each other in critical situations. On the other hand, in all operating conditions, DCMG not only feeds three-phase loads with time-varying active and reactive power on the grid side but also injects constant active power into the grid. During events, NGs support each other, NGs support DCMG, and DCMG supports NGs. Such control strategies are realized by the proposed control method to increase resilience of the system. For these purposes, all resources and loads in DCMG and NGs are equipped with individual controllers. Then, a central control unit analyzes, monitors, and regularizes performance of individual controllers in DCMG and NGs. Nonlinear simulations show the proposed model can effectively control DCMG and NGs under normal and critical conditions.

关键词： Control system DC microgrid nanogrid resilience

Interplay between temperature-dependent strengthening mechanisms and mechanical stability in high-performance austenitic stainless steels

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International Journal of Minerals,Metallurgy and Materials 2024年第10期31卷 2182-2188页

作者： Mohammad Javad Sohrabi Hamed Mirzadeh Saeed Sadeghpour Milad Zolfipour Aghdam Abdol reza Geranmayeh reza Mahmudi School of Metallurgy and Materials Engineering College of EngineeringUniversity of Tehran14395-515 TehranIran Centre for Advanced Steels Research Materials and Mechanical EngineeringUniversity of Oulu90014 OuluFinland Department of Mechanical Engineering College of EngineeringUniversity of Tehran14395-515 TehranIran

The effects of deformation temperature on the transformation-induced plasticity(TRIP)-aided 304L,twinning-induced plasti-city(TWIP)-assisted 316L,and highly alloyed stable 904L austenitic stainless steels were compared for the first time to tune the mechan-ical properties,strengthening mechanisms,and strength-ductility *** this purpose,the scanning electron microscopy(SEM),electron backscattered diffraction(EBSD),X-ray diffraction(XRD),tensile testing,work-hardening analysis,and thermodynamics calcu-lations were *** induced plasticity effects led to a high temperature-dependency of work-hardening behavior in the 304L and 316L stainless *** the deformation temperature increased,the metastable 304L stainless steel showed the sequence of TRIP,TWIP,and weakening of the induced plasticity mechanism;while the disappearance of the TWIP effect in the 316L stainless steel was also ***,the solid-solution strengthening in the 904L superaustenitic stainless steel maintained the tensile properties over a wide temper-ature range,surpassing the performance of 304L and 316L stainless *** this regard,the dependency of the total elongation on the de-formation temperature was less pronounced for the 904L alloy due to the absence of additional plasticity *** results re-vealed the importance of solid-solution strengthening and the associated high friction stress for superior mechanical behavior over a wide temperature range.

关键词： austenitic stainless steels mechanical behavior stacking fault energy metastability mechanical twinning