International Journal of Engineering - Transactions C: Aspects最新文献_第5页

Providing an Analytical Model in Determining Nanofluids 提供一种测定纳米流体的分析模型

International Journal of Engineering - Transactions C: Aspects Pub Date : 2017-09-08 DOI: 10.5829/ije.2017.30.12c.14

A. Shahriari, N. Jahantigh, F. Rakani

{"title":"Providing an Analytical Model in Determining Nanofluids","authors":"A. Shahriari, N. Jahantigh, F. Rakani","doi":"10.5829/ije.2017.30.12c.14","DOIUrl":"https://doi.org/10.5829/ije.2017.30.12c.14","url":null,"abstract":"The inﬂuence of temperature, mean nanoparticle size and the nanoparticle concentration on the dynamic viscosities of nanofluids are investigated in an analytical method followed by introduction of modified equations for calculating the nanoﬂuids’ viscosities. A new correlation is developed for effective viscosity based on the previous model where the Brownian movement of the nanoparticles is considered as the key mechanism. In previous studies, the proposed models were not appropriate for nanoparticles larger than 36 nm. They were also focused on low concentrations of nanoparticles up to 5%. The possibility of homogeneous dispersion of the nanoparticles and the Stokes law are observed here. This new model is explained in terms of temperature, mean nanoparticle diameter, nanoparticle volume concentration and both the nanoparticle and base fluid thermophysical characteristics for the effective viscosity of nanofluids. A combined correction factor is introduced to take into account the simpliﬁcation for a free stream boundary condition outside the boundary layer. A good agreement is observed between the effective viscosity obtained in this new model and those of recorded experiments conducted for different nanoﬂuids. The results show that the present model is valid for large volume concentration (0% < φ","PeriodicalId":14066,"journal":{"name":"International Journal of Engineering - Transactions C: Aspects","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86532824","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Base Level Evaluation in Buildings with Different Foundation Levels by Soil-foundation-structure Interaction 基于地基-基础-结构相互作用的不同基础水平建筑基准面评价

International Journal of Engineering - Transactions C: Aspects Pub Date : 2017-07-07 DOI: 10.5829/ije.2017.30.09c.01

V. Kalatjari, A. Naghizadeh, R. Naderi, M. Talebpour

{"title":"Base Level Evaluation in Buildings with Different Foundation Levels by Soil-foundation-structure Interaction","authors":"V. Kalatjari, A. Naghizadeh, R. Naderi, M. Talebpour","doi":"10.5829/ije.2017.30.09c.01","DOIUrl":"https://doi.org/10.5829/ije.2017.30.09c.01","url":null,"abstract":"The base level is among the effective parameters in determining the seismic force on a structure, if the equivalent-static method is used for analyzing a structure. It is obvious that the base level is located on foundation in buildings in which foundation is built in a single level and there is not any interaction between the structure's walls and the soil; however, in some buildings which have underground part, the foundation is built in two different levels which in turn makes the determination of the location of base level uncertain. Since no relevant recommendation has been provided in the seismic codes, this study tries to remove such uncertainties. For this purpose, the structural models along with foundation and their peripheral soil were modeled by the ABAQUS software and regarding the soil type it was tested by an artificial accelerogram compatible with the spectrum of the code. Two types of soil (stiff and soft) were used in this study. The results indicated that the base level location is considerably influenced by the soil type, the number of entrance columns leading to the underground and the number of stories of the structure.","PeriodicalId":14066,"journal":{"name":"International Journal of Engineering - Transactions C: Aspects","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77387097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Buying Group Design Considering the Member’s Interest 考虑成员利益的购买群体设计

International Journal of Engineering - Transactions C: Aspects Pub Date : 2017-07-07 DOI: 10.5829/idosi.ije.2017.30.09c.06

Abdul Sattar Safaei, S. Moshtaghi, M. Paydar

引用次数: 1

Selecting Efficient Service-providers in Electric Power Distribution Industry Using Combinatorial Reverse Auction 基于组合反向拍卖的配电行业高效服务提供商选择

International Journal of Engineering - Transactions C: Aspects Pub Date : 2017-07-07 DOI: 10.5829/idosi.ije.2017.30.09c.07

Reza Alaei, Mostafa Setak

{"title":"Selecting Efficient Service-providers in Electric Power Distribution Industry Using Combinatorial Reverse Auction","authors":"Reza Alaei, Mostafa Setak","doi":"10.5829/idosi.ije.2017.30.09c.07","DOIUrl":"https://doi.org/10.5829/idosi.ije.2017.30.09c.07","url":null,"abstract":"In this paper, a combinatorial reverse auction mechanism is proposed for selecting the most efficient service-providers for resolving sustained power interruptions in multiple regions of an electric power distribution company’s responsibility area. Through this mechanism, supplying the required service in each region is assigned to only one potential service-provider considering two criteria including cost and service time. So, the corresponding winner determination problem of the proposed auction mechanism is formulated as a bi-objective combinatorial optimization problem. However, finding a feasible solution for the formulated problem as well as its solving is NP-complete. Since exact optimization algorithms are failed in solving this kind of problems in a reasonable time, a problem specific metaheuristic called NSGA-II that is an evolutionary algorithm for solving multi-objective optimization problems is developed to estimate the set of Pareto optimal solutions of the formulated bi-objective winner determination problem. In our developed NSGA-II, two problem-specific operators are proposed for creating initial feasible solutions and converting infeasible solutions to feasible ones. Furthermore, a new method for determining the population size based on the size of problem instance is proposed. We conduct a computational experiment in which several randomly generated problem instances are solved using the proposed NSGA-II in different settings. Computational results of proposed algorithm in different settings are compared using a quality measure and statistical hypothesis tests. The results of performance comparison show that the proposed NSGA-II with a population size determined by proposed method and a different form of binary tournament method performs better in finding non-dominated solutions for different instances of formulated bi-objective optimization problem.","PeriodicalId":14066,"journal":{"name":"International Journal of Engineering - Transactions C: Aspects","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85147570","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Field Study and Evaluation of Buckling Behavior of Cylindrical Steel Tanks with Geometric Imperfections under Uniform External Pressure 具有几何缺陷的圆柱形钢储罐在均匀外压下屈曲行为的现场研究与评价

International Journal of Engineering - Transactions C: Aspects Pub Date : 2017-07-07 DOI: 10.5829/ije.2017.30.09c.03

M. Rastgar, H. Showkati

{"title":"Field Study and Evaluation of Buckling Behavior of Cylindrical Steel Tanks with Geometric Imperfections under Uniform External Pressure","authors":"M. Rastgar, H. Showkati","doi":"10.5829/ije.2017.30.09c.03","DOIUrl":"https://doi.org/10.5829/ije.2017.30.09c.03","url":null,"abstract":"Construction and assembling process of shell structures has caused main problems. In these structures, there is no possibility for the integrated construction due to their large shell extent and they are built using a number of welded curved panel parts; hence, some geometrical imperfections emerge. Most of these imperfections are caused by the process of welding, transportation, inappropriate rolling, as well as installation and implementation problems. In this research, construction of steel cylindrical tanks in one of the refinery site is monitored using a field survey and created imperfections are identified and introduced. Relying on the statistical inference, they are classified and then, by studying the effective factors and origin in their generation, the common imperfections are identified. The impact of common imperfections on the buckling behavior is experimentally evaluated under uniform external pressure. Then, nonlinear analysis of the test specimens are performed by ANSYS software. Finally experimental results, finite element and analytical relations are compared. The obtained results show that the imperfections have a direct impact on the structural behavior of shells during the buckling under uniform external pressure load. Also, some imperfections caused by welding increase the buckling resistance of cylindrical shells. doi: 10.5829/ije.2017.30.09c.03","PeriodicalId":14066,"journal":{"name":"International Journal of Engineering - Transactions C: Aspects","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80553060","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Pattern Recognition in Control Chart Using Neural Network based on a New Statistical Feature 基于新统计特征的神经网络控制图模式识别

International Journal of Engineering - Transactions C: Aspects Pub Date : 2017-07-07 DOI: 10.5829/idosi.ije.2017.30.09c.10

M. K. Naeini, N. Bayati

引用次数: 2

Case Mix Planning using The Technique for Order of Preference by Similarity to Ideal Solution and Robust Estimation: a Case Study 基于理想解相似性和鲁棒估计的偏好排序技术的案例组合规划:一个案例研究

International Journal of Engineering - Transactions C: Aspects Pub Date : 2017-07-07 DOI: 10.5829/idosi.ije.2017.30.09c.09

R. Shafaei, A. Mozdgir

{"title":"Case Mix Planning using The Technique for Order of Preference by Similarity to Ideal Solution and Robust Estimation: a Case Study","authors":"R. Shafaei, A. Mozdgir","doi":"10.5829/idosi.ije.2017.30.09c.09","DOIUrl":"https://doi.org/10.5829/idosi.ije.2017.30.09c.09","url":null,"abstract":"Management of surgery units and operating room (OR) play key roles in optimizing the utilization of hospitals. On this line Case Mix Planning (CMP) is normally applied to long term planning of OR. This refers to allocating OR time to each patient’s group. In this paper a mathematical model is applied to optimize the allocation of OR time among surgical groups. In addition, another technique is applied to provide an Order of Preference by Similarity to Ideal Solution (TOPSIS) considering different hospital performance measures. Furthermore, robust estimation approach is used to estimate the models' parameters using real data. The proposed model is solved using GAMS software. The results of the study performed in this paper reveal that the proposed methods results in an increase in total hospital operated “value of patients” by 21.5%. This value is defined according to hospital priority and includes moral and ethical considerations. In addition, for each resource, a sensitivity analysis of the findings to the changes is conducted. The results of the sensitivity analysis indicated that the value of the objective function significantly increased via reallocating OR time to surgical groups and/or enhancing the OR facilities to support more surgical specialties.","PeriodicalId":14066,"journal":{"name":"International Journal of Engineering - Transactions C: Aspects","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89142535","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

Buoyancy Term Evolution in the Multi Relaxation Time Model of Lattice Boltzmann Method with Variable Thermal Conductivity Using a Modified Set of Boundary Conditions 基于修正边界条件的变导热晶格玻尔兹曼法多松弛时间模型的浮力项演化

International Journal of Engineering - Transactions C: Aspects Pub Date : 2017-07-07 DOI: 10.5829/ije.2017.30.09c.14

M. Varmazyar, Arash Mohammadi, M. Bazargan

{"title":"Buoyancy Term Evolution in the Multi Relaxation Time Model of Lattice Boltzmann Method with Variable Thermal Conductivity Using a Modified Set of Boundary Conditions","authors":"M. Varmazyar, Arash Mohammadi, M. Bazargan","doi":"10.5829/ije.2017.30.09c.14","DOIUrl":"https://doi.org/10.5829/ije.2017.30.09c.14","url":null,"abstract":"During the last few years, a number of numerical boundary condition schemes have been used to study various aspects of the no-slip wall condition using the lattice Boltzmann method. In this paper, a modified boundary condition method is employed to simulate the no-slip wall condition in the presence of the body force term near the wall. These conditions are based on the idea of the bounce-back of the non-equilibrium distribution. The error associated with the modified model is smaller than those of other boundary condition models available in the literature. Additionally, various schemes to simulate body forces have been studied. Based on the numerical results, the model demonstrating minimum error has been reported. Finally, it has been shown that the present model is capable of simulating the effect of high nonlinearity in the heat transfer equation in the presence of a variable thermal conductivity. This has been accomplished by employing a multi relaxation time scheme to model a Rayleigh-Benard natural convection current in a 2-D domain with high Rayleigh numbers. Previous studies reported that the onset of oscillation occurs at Ra≈30,000 and Pr=6.0. By the modified boundary condition method which is used in this study, the oscillation is removed until at least Ra≈ 45,000 and Pr=6.0. The results show that applying scheme 3 for the current boundary condition yields the least amount of error compared to the semi-empirical correlation. The Rayleigh-Benard convection problem has been revisited in the presence of a variable thermal conductivity and the simulation results remain stable for flows with a large variation of thermal conductivity ( = 0.7) and Rayleigh numbers up to 1,000,000 and Pr=0.7.","PeriodicalId":14066,"journal":{"name":"International Journal of Engineering - Transactions C: Aspects","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87560359","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Fuzzy-rough Information Gain Ratio Approach to Filter-wrapper Feature Selection 滤波包装特征选择的模糊粗糙信息增益比方法

International Journal of Engineering - Transactions C: Aspects Pub Date : 2017-07-07 DOI: 10.5829/ije.2017.30.09c.05

A. Moaref, Vahid Sattari-Naeini

引用次数: 1

An Investigation on the Parameters Influencing the Pounding in Highway Bridges 影响公路桥梁冲击的参数研究

International Journal of Engineering - Transactions C: Aspects Pub Date : 2017-07-07 DOI: 10.5829/ije.2017.30.09c.02

M. Hoseinzadeh, S. Pourzeynali

引用次数: 2