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Acta Mechanica Sinica 2012年第5期28卷 1389-1397页

作者： amin Manouchehrian Mohammad Fatehi Marji Mining and Metallurgical Engineering Department Yazd University

In many situations rocks are subjected to biaxial loading and the failure process is controlled by the lateral confinement stresses. The importance of confinement stresses has been recognized in the literature by many researchers, in particular, its influence on strength and on the angle of fracture, but still there is not a clear description for the influence of confining stress on the crack propagation mechanism of rocks. This paper presents a numerical pro- cedure for the analysis of crack propagation in rock-like ma- terials under compressive biaxial loads. Several numerical simulations of biaxial tests on the rock specimen have been carried out by a bonded particle model （BPM） and the influ- ence of confinement on the mechanism of crack propagation from a single flaw in rock specimens is studied. For this purpose, several biaxial compressive tests on rectangular spec- imens under different confinement stresses were modeled in （2 dimensional particle flow code） PFC2D. The results show that wing cracks initiate perpendicular to the flaw and trend toward the direction of major stress, however, when the lat- eral stresses increase, this initiation angle gets wider. Also it is concluded that in addition to the material type, the initiation direction of the secondary cracks depends on confine- ment stresses, too. Besides, it is understood that secondary cracks may be produced from both tensile and shear mechanisms.

关键词： Crack propagation Confinement Bonded par-ticle model - Rock Secondary cracks

Role of dissolved oxygen reduction in improvement inhibition performance of ascorbic acid during copper corrosion in 0.50 mol/L sulphuric acid

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Chinese Chemical Letters 2010年第3期21卷 341-345页

作者： Mohammed A.amin Chemistry Department Faculty of ScienceAin Shams University

The kinetics of dissolved O_2 reduction and hydrogen evolution reactions on copper surface was studied in naturally aerated and air and O_2-saturated 0.50 mol/L H_2SO_4 solutions using polarization measurements combined with the rotating disc electrode (RDE).The Koutecky-Levich plot indicated that the dissolved O_2 reduction at the copper electrode was an apparent four-electron process.A correlation between the presence of dissolved O_2 and the formation of Cu_2O,confirmed from XRD,was discussed. Ascorbic a...

关键词： Copper Sulphuric acid solutions Corrosion inhibition Ascorbic acid RDE O_2 reduction

Application of nano silica to improve self-healing of asphalt mixes

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Journal of Central South University 2017年第5期24卷 1019-1026页

作者： Ganjei Mohamad amin Aflaki Esmail Department of Civil and Environmental Engineering Amirkabir University of TechnologyTehranIran

Nano silica due to its spherical shape, tiny size and higher density compared to bitumen, may have an inherent potential to improve hot mix asphalt(HMA) self-healing. In this research scanning electron microscopy(SEM) images were used to investigate size, morphology and dispersion of nano silica particles. Additionally, HMA self-healing mechanism was also examined by SEM. Furthermore, dynamic indirect tensile test(IDT) was used to evaluate HMA self-healing index. The SEM results indicated that bitumen mortar flowing into micro cracks may be one of the most important mechanisms of HMA self-healing. The experiment results also showed that modification of bitumen by nano silica promotes the ability of the HMA self-healing.

关键词： nano silica healing index Taguchi method hot mix asphalt

Development of a Colorimetric Loop-mediated Isothermal Amplification Assay for the Visual Detection of Fusarium oxysporum ***. melonis

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Horticultural Plant Journal 2019年第3期5卷 129-136页

作者： Mohammad amin Almasi Young Researchers and Elites Club North Tehran Branch Islamic Azad University

Fusarium wilt of melon, Fusarium oxysporum ***. melonis is one of the most important diseases, causing tremendous losses in melon growing areas in Iran. There is a real need for a rapid and inexpensive assay to facilitate accurate disease diagnosis and surveillance for better management of Fusarium wilt outbreaks. One of the procedures designed for detection of this disease is loop-mediated isothermal amplification(LAMP)assay; its efficiency has been contrasted with polymerase chain reaction(PCR). The translation elongation factor 1-alpha gene is basically used for designing the LAMP(i.e. F3, B3, FIP, and BIP) together with PCR(F and B). Using hydroxynaphthol blue(HNB) dye, LAMP was placed in a water bath after the optimization was done. The results show LAMP is an advantageous method because it is highly sensitive(100-fold), quite cheap,user-friendly, and safe; in addition, it is performed quickly by visual detection and does not require DNA extraction(in direct-LAMP). The LAMP is believed to be a simple and reliable tool for laboratory purposes because it needs only very basic instruments and the results can be observed and contrasted visually.

关键词： Direct-LAMP assay Fusarium oxysporum f.sp. melonis Visual detection

Hybrid meta-heuristic machine learning methods applied to landslide susceptibility mapping in the Sahel-Algiers

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International Journal of Sediment Research 2022年第5期37卷 601-618页

作者： Mohammed amin Benbouras Technology Department Ecole Normale Sup erieure D?Enseignement Technologique de Skikda (ENSET) Laboratoire Central des Travaux Publics (LCTP)

Landslides are considered as one among many phenomena jeopardizing human beings as well as their constructions. To prevent this disastrous problem, researchers have used several approaches for landslide susceptibility modeling, for the purpose of preparing accurate maps marking landslide prone *** the most frequently used approaches for landslide susceptibility mapping is the Artificial Neural Network(ANN) method. However, the effectiveness of ANN methods could be enhanced by using hybrid metaheuristic algorithms, which are scarcely applied in landslide mapping. In the current study, nine hybrid metaheuristic algorithms, genetic algorithm(GA)-ANN, evolutionary strategy(ES)-ANN, ant colony optimization(ACO)-ANN, particle swarm optimization(PSO)-ANN, biogeography based optimization(BBO)-ANN, gravitational search algorithm(GHA)-ANN, particle swarm optimization and gravitational search algorithm(PSOGSA)-ANN, grey wolves optimization(GWO)-ANN, and probability based incremental learning(PBIL)-ANN have been used to spatially predict landslide susceptibility in Algiers’ Sahel,Algeria. The modeling phase was done using a database of 78 landslides collected utilizing Google Earth images, field surveys, and six conditioning factors(lithology, elevation, slope, land cover, distance to stream, and distance to road). Initially, a gamma test was used to decrease the input variable ***, the optimal inputs have been modeled by the mean of hybrid metaheuristic ANN techniques and their performance was assessed through seven statistical indicators. The comparative study proves the effectiveness of the co-evolutionary PSOGSA-ANN model, which yielded higher performance in predicting landslide susceptibility compared to the other models. Sensitivity analysis using the stepby-step technique was done afterward, which revealed that the distance to the stream is the most influential factor on landslide susceptibility, followed by the slope factor which ranked second. L

关键词： Artificial neural network Hybrid metaheuristic optimization algorithms Landslide susceptibility Geographical information system Sensitivity analysis

Optimally Connected Hybrid Complex Networks with Windmill Graphs Backbone

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Journal of Systems Science & Complexity 2020年第4期33卷 903-929页

作者： SAFAEI Farshad BABAEI amin MOUDI Mehrnaz Faculty of Computer Science and Engineering Shahid Beheshti UniversityTehranIran School of Computer Science Institute for Research in Fundamental SciencesTehranIran Department of Computer Engineering University of Torbat HeydariehTorbat HeydariehIran

The significance of the existing analysis methods in complex networks and easy access to the ever-increasing volume of information present the emergence of proposing new methods in various fields based on complex system ideas. However, these systems are usually faced with various random failures and intelligent attacks. Due to the nature of the components’ behaviors, the occurrence of the failures and faults in their operations and the alteration of their topologies are the most important problems. Since the complex systems are usually used as the infrastructures of other networks, their robustness against failures and the adoption of suitable precautions are necessary. Moreover, the smallworld effect in most complex systems is one of the crucial structural features. The authors found that the relation between these two is not well-known and may even be in conflict in some networks. The main goal in this paper is to achieve an optimal topology by utilizing a robustness-oriented multiobjective trade-off optimization model(edge rewiring) to establish a peaceful relationship between the two requirements. By offering a proposed rewiring method with the small-world effect, which is called core-periphery Windmill property, the authors demonstrated that the generated networks are able to exhibit appropriate robustness even during intelligent attacks. The results obtained in terms of Windmill graphs are presented very good approximations to demonstrate the small-world effect. These graphs are used as the initial core in the construction of the optimized networks’ topologies.

关键词： effect. utilizing Optimal

Fast Protection Scheme for Active Distribution Networks: Breaking Chains by Utilizing Auxiliary Relays

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Journal of Modern Power Systems and Clean Energy 2020年第3期8卷 540-548页

作者： amin Yazdaninejadi Daryoush Nazarpour Vahid Talavat Department of Electrical Engineering Shahid Rajaee Teacher Training UniversityTehranIran Urmia University UrmiaIran

Due to the swift expansion and the deployment of distributed generation, protection systems of active distribution networks are more expected to be fast. In loop-based active distribution networks, directional overcurrent relays(DOCRs) are caught in different chains. These chains stand as the severe obstacle to follow fast-response protection, which remains a significant challenge. In this paper, to overcome this challenge, a fast protection scheme is proposed to break the chains in the corresponding loops by deploying auxiliary DOCRs. The most effective constraint associated with each chain is relaxed during the coordination process. Then, the auxiliary relays are employed to play the backup roles instead of conventional backup relays in the relaxed constraints. To avoid the misoperation of relays in the proposed scheme, low bandwidth communication links are suitably employed. Furthermore, the auxiliary relays are optimally placed and adjusted. The proposed approach demonstrates a mixed-integer nonlinear programming model which is tackled by particle swarm optimization(PSO) algorithm. Detailed simulation studies are carried out to verify the performance of the proposed approach.

关键词： Fast protection scheme directional overcurrent relays active distribution network backup relay auxiliary relay

Regularity classification and corresponding analysis method requirements of horizontally curved bridges with unequal pier heights

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Earthquake Engineering and Engineering Vibration 2023年第2期22卷 549-571页

作者： Mohammad Jalal Maleki-amin Shahrokh Maalek School of Civil Engineering Tehran UniversityTehran 11155-4563Iran Iranian Bridge Engineering Association Tehran 36481684Iran

The seismic behavior of horizontally curved bridges,particularly with unequal height piers,is more complicated than that of straight bridges due to their geometric *** this study,the seismic responses of several horizontally curved single-column-bent viaducts with various degrees of curvature and different pier heights have been investigated,employing three different analysis approaches:namely,modal pushover analysis,uniform load method,and nonlinear time history *** the investigated bridge configurations and utilizing the most common regularity indices,the results indicate that viaducts with 45-degree and 90-degree deck subtended angles can be categorized as regular and moderately irregular,respectively,while the bridges with 180-degree deck subtended angle are found to be highly ***,the viaducts whose pier heights are asymmetric may be considered as irregular for almost all ranges of the deck subtended *** effects of higher transverse and longitudinal modes are discussed and the minimum analysis requirements are identified to assess the seismic response of such bridge configurations for design *** the Regularity Indices used here are useful tools to distinguish between regular and irregular bridges,further studies are needed to improve their reliability.

关键词： horizontally curved bridges unequal height piers pushover analysis regularity index seismic analysis and response

Economical Requirements Elicitation Techniques During COVID-19: A Systematic Literature Review

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Computers, Materials & Continua 2021年第5期67卷 2665-2680页

作者： Tauqeer ul amin Basit Shahzad Fazal-e-amin Muhammad Shoaib Department of Software Engineering National University of Modern LanguagesIslamabadPakistan Department of Software Engineering College of Computer and Information SciencesKing Saud UniversityRiyadhSaudi Arabia

Requirements elicitation is a fundamental phase of software development in which an analyst discovers the needs of different stakeholders and transforms them into *** phase is cost-and time-intensive,and a project may fail if there are excessive costs and schedule ***-19 has affected the software industry by reducing interactions between developers and *** a lack of interaction is a key reason for the failure of software *** can also fail when customers do not know precisely what they ***,selecting the unsuitable elicitation technique can also cause project *** present study,therefore,aimed to identify which requirements elicitation technique is the most cost-effective for large-scale projects when time to market is a critical issue or when the customer is not *** that end,we conducted a systematic literature review on requirements elicitation *** primary studies identified introspection as the best technique,followed by survey and *** finding suggests that introspection should be the first choice of elicitation technique,especially when the customer is not available or the project has strict time and cost ***,introspection should also be used as the starting point in the elicitation process of a large-scale project,and all known requirements should be elicited using this technique.

关键词： COVID-19 software engineering requirements engineering requirements elicitation introspection project failure SLR on elicitation techniques large-scale projects economical elicitation techniques costeffective time constraints

Microstructure and mechanical characteristics of AA6061-T6 joints produced by friction stir welding,friction stir vibration welding and tungsten inert gas welding:A comparative study

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International Journal of Minerals,Metallurgy and Materials 2021年第3期28卷 450-461页

作者： Behrouz Bagheri Mahmoud Abbasi amin Abdollahzadeh Department of Mining and Metallurgy Amirkabir University of TechnologyTehranIran Faculty of Engineering University of KashanRavandi Blvd.KashanIran Department of Materials Science and Engineering Faculty of EngineeringShahid Chamran University of AhvazAhvazIran

This study compared the microstructure and mechanical characteristics of AA6061-T6 joints produced using friction stir welding(FSW),friction stir vibration welding(FSVW),and tungsten inert gas welding(TIG).FSVW is a modified version of FSW wherein the joining specimens are vibrated normal to the welding line during *** results indicated that the weld region grains for FSVW and FSW were equiaxed and were smaller than the grains for *** addition,the weld region grains for FSVW were finer compared with those for *** also showed that the strength,hardness,and toughness values of the joints produced by FSVW were higher than those of the other joints produced by FSW and *** vibration during FSW enhanced dynamic recrystallization,which led to the development of finer *** weld efficiency of FSVW was approximately 81%,whereas those of FSW and TIG were approximately 74%and 67%,respectively.

关键词： friction stir welding vibration tungsten inert gas welding mechanical characteristics microstructure