Search results for: Alireza Kashani
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 244

Search results for: Alireza Kashani

244 Topology Optimisation for Reduction in Material Use for Precast Concrete Elements: A Case Study of a 3D-Printed Staircase

Authors: Dengyu You, Alireza Kashani

Abstract:

This study explores the potential of 3D concrete printing in manufacturing prefabricated staircases. The applications of 3D concrete printing in large-scale construction could enhance the industry’s implementation of the Industry 4.0 concept. In addition, the current global challenge is to achieve Net Zero Emissions by 2050. Innovation in the construction industry could potentially speed up achieving this target. The 3D printing technology offers a possible solution that reduces cement usage, minimises framework wastes, and is capable of manufacturing complex structures. The performance of the 3D concrete printed lightweight staircase needs to be evaluated. In this study, the staircase is designed using computer-aided technologies, fabricated by 3D concrete printing technologies, and tested with Australian Standard (AS 1657-2018 Fixed platforms, walkways, stairways, and ladders – design, construction, and installation) under a laboratory environment. The experiment results will be further compared with the FEM analysis. The results indicate that 3D concrete printing is capable of fast production, reducing material usage, and is highly automotive, which meets the industry’s future development goal.

Keywords: concrete 3D printing, staircase, sustainability, automation

Procedia PDF Downloads 68
243 An Intergenerational Study of Iranian Migrant Families in Australia: Exploring Language, Identity, and Acculturation

Authors: Alireza Fard Kashani

Abstract:

This study reports on the experiences and attitudes of six Iranian migrant families, from two groups of asylum seekers and skilled workers, with regard to their language, identity, and acculturation in Australia. The participants included first generation parents and 1.5-generation adolescents, who had lived in Australia for a minimum of three years. For this investigation, Mendoza’s (1984, 2016) acculturation model, as well as poststructuralist views of identity, were employed. The semi-structured interview results have highlighted that Iranian parents and adolescents face low degrees of intergenerational conflicts in most domains of their acculturation. However, the structural and lawful patterns in Australia have caused some internal conflicts for the parents, especially fathers (e.g., their power status within the family or their children’s freedom). Furthermore, while most participants reported ‘cultural eclecticism’ as their preferred acculturation orientation, female participants seemed to be more eclectic than their male counterparts who showed inclination towards keeping more aspects of their home culture. This finding, however, highlights a meaningful effort on the part of husbands that in order to make their married lives continue well in Australia they need to re-consider the traditional male-dominated customs they used to have in Iran. As for identity, not only the parents but also the adolescents proudly identified themselves as Persians. In addition, with respect to linguistic behaviour, almost all adolescents showed enthusiasm to retain the Persian language at home to be able to maintain contacts with their relatives and friends in Iran and to enjoy many other benefits the language may offer them in the future.

Keywords: acculturation, asylum seekers, identity, intergenerational conflicts, language, skilled workers, 1.5 generation

Procedia PDF Downloads 199
242 The Reason Why Al-Kashi’s Understanding of Islamic Arches Was Wrong

Authors: Amin Moradi, Maryam Moeini

Abstract:

It is a widely held view that Ghiyath al-Din Jamshid-e-Kashani, also known as al-Kashi (1380-1429 CE), was the first who played a significant role in the interaction between mathematicians and architects by introducing theoretical knowledge in Islamic architecture. In academic discourses, geometric rules extracted from his splendid volume titled as Key of Arithmetic has uncritically believed by historians of architecture to contemplate the whole process of arch design all throughout the Islamic buildings. His theories tried to solve the fundamental problem of structural design and to understand what makes an Islamic structure safe or unsafe. As a result, al-Kashi arrived at the conclusion that a safe state of equilibrium is achieved through a specific geometry as a rule. This paper reassesses the stability of al-Kashi's systematized principal forms to evaluate the logic of his hypothesis with a special focus on large spans. Besides the empirical experiences of the author in masonry constructions, the finite element approach was proposed considering the current standards in order to get a better understanding of the validity of geometric rules proposed by al-Kashi for the equilibrium conditions of Islamic masonry arches and vaults. The state of damage of his reference arches under loading condition confirms beyond any doubt that his conclusion of the geometrical configuration measured through his treaties present some serious operational limits and do not go further than some individualized mathematical hypothesis. Therefore, the nature of his mathematical studies regarding Islamic arches is in complete contradiction with the practical knowledge of construction methodology.

Keywords: Jamshid al-Kashani, Islamic architecture, Islamic geometry, construction equilibrium, collapse mechanism

Procedia PDF Downloads 93
241 Optimization of Structures Subjected to Earthquake

Authors: Alireza Lavaei, Alireza Lohrasbi, Mohammadali M. Shahlaei

Abstract:

To reduce the overall time of structural optimization for earthquake loads two strategies are adopted. In the first strategy, a neural system consisting self-organizing map and radial basis function neural networks, is utilized to predict the time history responses. In this case, the input space is classified by employing a self-organizing map neural network. Then a distinct RBF neural network is trained in each class. In the second strategy, an improved genetic algorithm is employed to find the optimum design. A 72-bar space truss is designed for optimal weight using exact and approximate analysis for the El Centro (S-E 1940) earthquake loading. The numerical results demonstrate the computational advantages and effectiveness of the proposed method.

Keywords: optimization, genetic algorithm, neural networks, self-organizing map

Procedia PDF Downloads 268
240 Dam Break Model Using Navier-Stokes Equation

Authors: Alireza Lohrasbi, Alireza Lavaei, Mohammadali M. Shahlaei

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The liquid flow and the free surface shape during the initial stage of dam breaking are investigated. A numerical scheme is developed to predict the wave of an unsteady, incompressible viscous flow with free surface. The method involves a two dimensional finite element (2D), in a vertical plan. The Naiver-Stokes equations for conservation of momentum and mass for Newtonian fluids, continuity equation, and full nonlinear kinematic free-surface equation were used as the governing equations. The mapping developed to solve highly deformed free surface problems common in waves formed during wave propagation, transforms the run up model from the physical domain to a computational domain with Arbitrary Lagrangian Eulerian (ALE) finite element modeling technique.

Keywords: dam break, Naiver-Stokes equations, free-surface flows, Arbitrary Lagrangian-Eulerian

Procedia PDF Downloads 294
239 Guidance and Control of a Torpedo Autonomous Underwater Vehicle

Authors: Soheil Arash Moghadam, Abdol R. Kashani Nia, Ali Akrami Zade

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Considering numerous applications of Autonomous Underwater Vehicles in various industries, there has been plenty of researches and studies on the motion control of such vehicles. One of the useful aspects for studying is the guidance of these vehicles. In this paper, while presenting motion equations with six degrees of freedom for Autonomous Underwater Vehicles, Proportional Navigation Guidance Law and the first order sliding mode control for TAIPAN AUV was used to address its guidance for the purpose of collision with a moving target.

Keywords: Autonomous Underwater Vehicle (AUV), degree of freedom (DOF), hydrodynamic, line of sight(LOS), proportional navigation guidance(PNG), sliding mode control(SMC)

Procedia PDF Downloads 432
238 Waste Generation in Iranian Building Industry: Addressing a Theory

Authors: Golnaz Moghimi, Alireza Afsharghotli, Alireza Rezaei

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Construction waste has been gradually increased as a result of upsizing construction projects which are occurred within the lifecycle of buildings. Since waste management is a major priority and has profound impacts on the volume of waste generated in construction stage, the majority of efforts have been attempted to reuse, recycle and reduce waste. However, there is still room to study on lack of sufficient knowledge about waste management in construction industry. This paper intends to provide an insight into the effect of project management knowledge areas on waste management solely on construction stage. To this end, a survey among Iranian building construction industry contractors was conducted to identify the effectiveness of project management knowledge areas on three jobsite key factors including ‘Site activity’, ‘Training’, and ‘Awareness’. As a result, four management disciplines were identified as most influential ones on amount of construction waste. These disciplines were Project Cost Management, Quality Management, Human Resource Management, and Integration Management. Based on the research findings, a new model was presented to develop effective construction waste strategies.

Keywords: awareness, PMBOK, site activity, training, waste management

Procedia PDF Downloads 308
237 Investigating Sustainable Neighborhood Development in Jahanshahr

Authors: Khashayar Kashani Jou, Ilnaz Fathololoomi

Abstract:

Nowadays, access to sustainable development in cities is assumed as one of the most important goals of urban managers. In the meanwhile, neighborhood as the smallest unit of urban spatial organization has a substantial effect on urban sustainability. Hence, attention to and focus on this subject is highly important in urban development plans. The objective of this study is evaluation of the status of Jahanshahr Neighborhood in Karaj city based on sustainable neighborhood development indicators. This research has been applied based on documentary method and field surveys. Also, evaluating of Jahanshahr Neighborhood of Karaj shows that it has a high level in sustainability in physical and economical dimension while a low level in cultural and social dimension. For this purpose, this neighborhood as a semi-sustainable neighborhood must take measures for development of collective spaces and efficiency of utilizing the public neighborhood spaces via collaboration of citizens and officials.

Keywords: neighborhood, sustainable development, sustainable neighborhood development, Jahanshahr neighborhood

Procedia PDF Downloads 242
236 A Framework for ERP Project Evaluation Based on BSC Model: A Study in Iran

Authors: Mohammad Reza Ostad Ali Naghi Kashani, Esfanji Elia

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Nowadays, the amounts of companies which tend to have an Enterprise Resource Planning (ERP) application are increasing particularly in developing countries like Iran. ERP projects are expensive, time consuming, and complex, in addition the failure rate is high among these projects. It is important to know whether these projects could meet their goals or not. Furthermore, the area which should be improved should be identified. In this paper we made a framework to evaluate ERP projects success implementation. First, based on literature review we made a framework based on BSC model, financial, customer, processes, learning and knowledge, because of the importance of change management it was added to model. Then an organization was divided in three layers. We choose corporate, managerial, and operational levels. Then to find criteria to assess each aspect, we use Delphi method in two rounds. And for the second round we made a questionnaire and did some statistical tasks on them. Based on the statistical results some of them are accepted and others are rejected.

Keywords: ERP, BSC, ERP project evaluation, IT projects

Procedia PDF Downloads 292
235 ERP Implementation in Iran: A Successful Experience in DGC

Authors: Mohammad Reza Ostad Ali Naghi Kashani

Abstract:

Nowadays, the amounts of companies which tend to have an Enterprise Resource Planning (ERP) application are increasing. Although ERP projects are expensive, time consuming, and complex, there are some successful experiences. These days, developing countries are striving to implement ERP projects successfully; however, there are many obstacles. Therefore, these projects would be failed or partially failed. This paper concerns the implementation of a successful ERP implementation, IFS, in Iran at Dana Geophysics Company (DGC). After a short review of ERP and ERP market in Iran, we propose a three phases deployment methodology (phase 1: Preparation and Business Process Management (BPM) phase 2: implementation and phase 3: testing, golive-1 (pilot) and golive-2 (final)). Then, we present five guidelines (Project Management, Change Management, Business Process Management (BPM), Training& Knowledge Management, and Technical Management), which were chose as work streams. In this case study we present lessons learned in Project management and Business process Management.

Keywords: business process management, critical success factors, ERP, project management

Procedia PDF Downloads 453
234 Fuzzy Implicative Pseudo-Ideals of Pesudo-BCK Algebras

Authors: Alireza Gilani

Abstract:

In this paper, we consider the fuzzification of implicative pseudo-ideal in a pseudo-BCK algebra, and then we investigate some of their properties. We prove that the family of fuzzy implicative pseudo-ideal is completely distributive lattice.

Keywords: BCK-algebra, pseudo-BCK algebra, pseudo-ideal, implicative pseudo-ideal

Procedia PDF Downloads 336
233 A New Center of Motion in Cabling Robots

Authors: Alireza Abbasi Moshaii, Farshid Najafi

Abstract:

In this paper a new model for centre of motion creating is proposed. This new method uses cables. So, it is very useful in robots because it is light and has easy assembling process. In the robots which need to be in touch with some things this method is very good. It will be described in the following. The accuracy of the idea is proved by an experiment. This system could be used in the robots which need a fixed point in the contact with some things and make a circular motion. Such as dancer, physician or repair robots.

Keywords: centre of motion, robotic cables, permanent touching, mechatronics engineering

Procedia PDF Downloads 399
232 Impact of FACTS Devices on Power Networks Reliability

Authors: Alireza Alesaadi

Abstract:

Flexible AC transmission system (FACTS) devices have an important rule on expnded electrical transmission networks. In this paper, the effect of these diveces on reliability of electrical networks is studied and it is shown that using of FACTS devices can improve the relibiability of power networks, significantly.

Keywords: FACTS devices, power networks, reliability

Procedia PDF Downloads 378
231 Views and Experiences of Medical Students of Kerman University of Medical Sciences on Facilitators and Inhibitators of Quality of Education in the Clinical Education System in 2021

Authors: Hossein Ghaedamini, Salman Farahbakhsh, Alireza Amirbeigi, Zahra Saghafi, Salman Daneshi, Alireza Ghaedamini

Abstract:

Background: Assessing the challenges of clinical education of medical students is one of the most important and sensitive parts of medical education. The aim of this study was to investigate the views and experiences of Kerman medical students on the factors that facilitate and inhibit the quality of clinical education. Materials and Methods: This research was qualitative and used a phenomenological approach. The study population included medical interns of Kerman University of Medical Sciences in 1400. The method of data collection was in-depth interviews with participants. Data were encoded and analyzed by Claizey stepwise model. Results: First, about 540 primary codes were extracted in the form of two main themes (facilitators and inhibitors) and 10 sub-themes including providing motivational models and creating interest in interns, high scientific level of professors and the appropriate quality of their teaching, the use of technology in the clinical education process, delegating authority and freedom of action and more responsibilities to interns, inappropriate treatment of some officials, professors, assistants and department staff with their interns, inadequate educational programming, lack of necessary cooperation and providing inappropriate treatment by clinical training experts for interns, inadequate evaluation method in clinical training for interns, poor quality mornings, the unefficiency of grand rounds, the inappropriate way of evaluating clinical training for interns, the lack of suitable facilities and conditions with the position of a medical intern, and the hardwork of some departments were categorized. Conclusion: Clinical education is always mixed with special principles and subtleties, and special attention to facilitators and inhibitors in this process has an important role in improving its quality.

Keywords: clinical education, medical students, qualitative study, education

Procedia PDF Downloads 41
230 Evaluation of the Cities Specific Characteristics in the Formation of the Safavid Period Mints

Authors: Mahmood Seyyed, Akram Salehi Heykoei, Hamidreza Safakish Kashani

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Among the remaining resource of the past, coins considered as an authentic documents among the most important documentary sources. The coins were minted in a place that called mint. The number and position of the mints in each period reflects the amount of economic power, political security and business growth, which was always fluctuated its position with changing the political and economic condition. Considering that, trade has more growth during the Safavid period than previous ones, the mint also has been in greater importance. It seems the one hand, the growth of economic in Safavid period has a direct link with the number and places of the mints at that time and in the other hand, the mints have been formed in some places because of the specific characteristic of cities and regions. Increasing the number of mints in the north of the country due to the growth of silk trade and in the west and northwest due to the political and commercial relation with Ottoman Empire, also the characteristics such as existence of mines, located in the Silk Road and communication ways, all are the results of this investigation. Accordingly, in this article researcher tries to examine the characteristics that give priority to a city for having mint. With considering that in the various historical periods, the mints were based in the most important cities in terms of political and social, at that time, this article examines the cities specific characteristics in the formation of the mints in Safavid period.

Keywords: documentary sources, coins, mint, city, Safavid

Procedia PDF Downloads 236
229 Passive and Active Spatial Pendulum Tuned Mass Damper with Two Tuning Frequencies

Authors: W. T. A. Mohammed, M. Eltaeb, R. Kashani

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The first bending modes of tall asymmetric structures in the two lateral X and Y-directions have two different natural frequencies. To add tuned damping to these bending modes, one needs to either a) use two pendulum-tuned mass dampers (PTMDs) with one tuning frequency, each PTMD targeting one of the bending modes, or b) use one PTMD with two tuning frequencies (one in each lateral directions). Option (a), being more massive, requiring more space, and being more expensive, is less attractive than option (b). Considering that the tuning frequency of a pendulum depends mainly on the pendulum length, one way of realizing option (b) is by constraining the swinging length of the pendulum in one direction but not in the other; such PTMD is dubbed passive Bi-PTMD. Alternatively, option (b) can be realized by actively setting the tuning frequencies of the PTMD in the two directions. In this work, accurate physical models of passive Bi-PTMD and active PTMD are developed and incorporated into the numerical model of a tall asymmetric structure. The model of PTMDs plus structure is used for a)synthesizing such PTMDs for particular applications and b)evaluating their damping effectiveness in mitigating the dynamic lateral responses of their target asymmetric structures, perturbed by wind load in X and Y-directions. Depending on how elaborate the control scheme is, the active PTMD can either be made to yield the same damping effectiveness as the passive Bi-PTMD of the same size or the passive Bi-TMD twice as massive as the active PTMD.

Keywords: active tuned mass damper, high-rise building, multi-frequency tuning, vibration control

Procedia PDF Downloads 54
228 Innovative Design of Spherical Robot with Hydraulic Actuator

Authors: Roya Khajepour, Alireza B. Novinzadeh

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In this paper, the spherical robot is modeled using the Band-Graph approach. This breed of robots is typically employed in expedition missions to unknown territories. Its motion mechanism is based on convection of a fluid in a set of three donut vessels, arranged orthogonally in space. This robot is a non-linear, non-holonomic system. This paper utilizes the Band-Graph technique to derive the torque generation mechanism in a spherical robot. Eventually, this paper describes the motion of a sphere due to the exerted torque components.

Keywords: spherical robot, Band-Graph, modeling, torque

Procedia PDF Downloads 305
227 A Survey on Important Factors of the Ethereum Network Performance

Authors: Ali Mohammad Mobaser Azad, Alireza Akhlaghinia

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Blockchain is changing our world and launching a new generation of decentralized networks. Meanwhile, Blockchain-based networks like Ethereum have been created and they will facilitate these processes using tools like smart contracts. The Ethereum has fundamental structures, each of which affects the activity of the nodes. Our purpose in this paper is to review similar research and examine various components to demonstrate the performance of the Ethereum network and to do this, and we used the data published by the Ethereum Foundation in different time spots to examine the number of changes that determine the status of network performance. This will help other researchers understand better Ethereum in different situations.

Keywords: blockchain, ethereum, smart contract, decentralization consensus algorithm

Procedia PDF Downloads 172
226 An Integrated Framework for Seismic Risk Mitigation Decision Making

Authors: Mojtaba Sadeghi, Farshid Baniassadi, Hamed Kashani

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One of the challenging issues faced by seismic retrofitting consultants and employers is quick decision-making on the demolition or retrofitting of a structure at the current time or in the future. For this reason, the existing models proposed by researchers have only covered one of the aspects of cost, execution method, and structural vulnerability. Given the effect of each factor on the final decision, it is crucial to devise a new comprehensive model capable of simultaneously covering all the factors. This study attempted to provide an integrated framework that can be utilized to select the most appropriate earthquake risk mitigation solution for buildings. This framework can overcome the limitations of current models by taking into account several factors such as cost, execution method, risk-taking and structural failure. In the newly proposed model, the database and essential information about retrofitting projects are developed based on the historical data on a retrofit project. In the next phase, an analysis is conducted in order to assess the vulnerability of the building under study. Then, artificial neural networks technique is employed to calculate the cost of retrofitting. While calculating the current price of the structure, an economic analysis is conducted to compare demolition versus retrofitting costs. At the next stage, the optimal method is identified. Finally, the implementation of the framework was demonstrated by collecting data concerning 155 previous projects.

Keywords: decision making, demolition, construction management, seismic retrofit

Procedia PDF Downloads 207
225 Investigation of Riprap Stability on Roughness Bridge Pier in River Bend

Authors: A. Alireza Masjedi, B. Amir Taeedi

Abstract:

In this research, by placing the two cylindrical piers without roughness and with roughness with riprap around its, they proceeded to a series of tests. Experiments were done by three relative diameters of riprap with density 2.1 and one rate of discharge 27 lit/s under pure water condition. In each experiment, flow depth measured in terms of failure threshold then stability number calculated by using data obtained. The results of the research showed that the riprap stability in pier with roughness is more pier without roughness because of the pier with roughness is sharp-pointed and reduced horseshoe vortex.

Keywords: riprap stability, roughness, river bend, froude number

Procedia PDF Downloads 310
224 Effect of Riprap Stability on Roughness Bridge Pier in River Bend

Authors: Alireza Masjedi, Amir Taeedi

Abstract:

In this research, by placing the two cylindrical piers without roughness and with roughness with riprap around its, they proceeded to a series of tests. Experiments were done by three relative diameters of riprap with density 2.1 and one rate of discharge 27 lit/s under pure water condition. In each experiment, flow depth measured in terms of failure threshold then stability number calculated by using data obtained. The results of the research showed that the riprap stability in pier with roughness is more pier without roughness because of the pier with roughness is sharp-pointed and reduced horseshoe vortex.

Keywords: riprap stability, roughness, river bend, froude number

Procedia PDF Downloads 302
223 Equations of Pulse Propagation in Three-Layer Structure of As2S3 Chalcogenide Plasmonic Nano-Waveguides

Authors: Leila Motamed-Jahromi, Mohsen Hatami, Alireza Keshavarz

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This research aims at obtaining the equations of pulse propagation in nonlinear plasmonic waveguides created with As2S3 chalcogenide materials. Via utilizing Helmholtz equation and first-order perturbation theory, two components of electric field are determined within frequency domain. Afterwards, the equations are formulated in time domain. The obtained equations include two coupled differential equations that considers nonlinear dispersion.

Keywords: nonlinear optics, plasmonic waveguide, chalcogenide, propagation equation

Procedia PDF Downloads 371
222 Influence of the Substitution of C for Mg and Ni on the Microstructure and Hydrogen Storage Characteristics of Mg2Ni Alloys

Authors: Sajad Haghanifar, Seyed-Farshid Kashani Bozorg

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Nano-crystalline Mg2Ni-based powder was produced by mechanical alloying technique using binary and ternary powder mixtures with stoichiometric compositions of Mg2Ni, Mg1.9C0.1Ni and Mg2C0.1Ni0.9. The structures and morphologies of the milled products were studied by XRD, SEM and HRTEM. Their electrochemical hydrogen storage characteristics were investigated in 6 M KOH solution. X-Ray diffraction, scanning and transmission electron microscopy of the milled products showed the formation of Mg2Ni-based nano-crystallites after 5, 15 and 30 h of milling using the initial powder mixtures of Mg1.9C0.1Ni, Mg2Ni and Mg2C0.1Ni0.9, respectively. It was found that partial substitution of C for Mg has beneficial effect on the formation kinetic of nano-crystalline Mg2Ni. Contrary to this, partial substitution of C for Ni was resulted in retardation of formation kinetic of nano-crystalline Mg2Ni. In addition, the negative electrode made from Mg1.9C0.1Ni ternary milled product after 30 hour of milling exhibited the highest initial discharge capacity and longest discharge life. Thus, partial substitution of C for Mg is beneficial to electrode properties of the Mg2Ni-based crystallites. The relation between the discharge capacity and cycling number of mechanically alloyed products was proposed on the basis of the fact that the degradation of discharge capacity was mainly caused by the oxidation of magnesium and nickel. The experimental data fitted the deduced equation well.

Keywords: Mg2Ni, hydrogen absorbing materials, electrochemical properties, nano-crystalline, amorphous, mechanical alloying, carbon

Procedia PDF Downloads 402
221 Reliability Improvement of Power System Networks Using Adaptive Genetic Algorithm

Authors: Alireza Alesaadi

Abstract:

Reliability analysis is a powerful method for determining the weak points of the electrical networks. In designing of electrical network, it is tried to design the most reliable network with minimal system shutting down, but it is usually associated with increasing the cost. In this paper, using adaptive genetic algorithm, a method was presented that provides the most reliable system with a certain economical cost. Finally, the proposed method is applied to a sample network and results will be analyzed.

Keywords: reliability, adaptive genetic algorithm, electrical network, communication engineering

Procedia PDF Downloads 459
220 Optimal Energy Consumption with Semiconductor Lamps

Authors: Pejman Hosseiniun, Rose Shayeghi, Alireza Farzaneh, Abolghasem Ghasempour

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Using LED lamps as lighting resources with new technology in designing lighting systems has been studied in this article. In this respect a history of LED emergence, its different manufacturing methods and technologies were revised, then their structure, light production line, its application and benefits in lighting industry has been evaluated. Finally, there is a comparison between these lamps and ordinary lamps to assess light parameters as well as energy consumption using DIALux software. Considering the results of analogies LED lamps have lower consumption and more lighting yield, therefore they are more economically feasible. Color variety, longer usage lap (circa 10 years) and compatibility with DC voltages are other LED lamps perquisites.

Keywords: LED, lighting efficiency, lighting intensity, luminance

Procedia PDF Downloads 553
219 Mechanical Properties of Palm Oil-Based Resin Containing Unsaturated Polyester

Authors: Alireza Fakhari, Abdul Razak Rahmat

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In this study, new palm oil-based polymer systems have been produced by blending unsaturated polyester (UPE) and maleinated, acrylated epoxidized palm oil (MAEPO). The MAEPO/UPE ratio was varied between 10/90 and 40/60 wt%. The influences of various loadings of MAEPO (10, 20, 30, and 40 wt%) on tensile, flexural and impact properties of resulting polymer systems were investigated. The results revealed that, these bio-based polymer systems exhibit mechanical properties comparable to those of petroleum-based polymers.

Keywords: palm oil, bio-based resin, renewable resources, unsaturated polyester resin

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218 Investigation of the Flow in Impeller Sidewall Gap of a Centrifugal Pump Using CFD

Authors: Mohammadreza DaqiqShirazi, Rouhollah Torabi, Alireza Riasi, Ahmad Nourbakhsh

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In this paper, the flow in a sidewall gap of an impeller which belongs to a centrifugal pump is studied using numerical method. The flow in sidewall gap forms internal leakage and is the source of “disk friction loss” which is the most important cause of reduced efficiency in low specific speed centrifugal pumps. Simulation is done using CFX software and a high quality mesh, therefore the modeling error has been reduced. Navier-Stokes equations have been solved for this domain. In order to predict the turbulence effects the SST model has been employed.

Keywords: numerical study, centrifugal pumps, disk friction loss, sidewall gap

Procedia PDF Downloads 486
217 Numerical Modelling of Crack Initiation around a Wellbore Due to Explosion

Authors: Meysam Lak, Mohammad Fatehi Marji, Alireza Yarahamdi Bafghi, Abolfazl Abdollahipour

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A wellbore is a hole that is drilled to aid in the exploration and recovery of natural resources including oil and gas. Occasionally, in order to increase productivity index and porosity of the wellbore and reservoir, the well stimulation methods have been used. Hydraulic fracturing is one of these methods. Moreover, several explosions at the end of the well can stimulate the reservoir and create fractures around it. In this study, crack initiation in rock around the wellbore has been numerically modeled due to explosion. One, two, three, and four pairs of explosion have been set at the end of the wellbore on its wall. After each stage of the explosion, results have been presented and discussed. Results show that this method can initiate and probably propagate several fractures around the wellbore.

Keywords: crack initiation, explosion, finite difference modelling, well productivity

Procedia PDF Downloads 244
216 Numerical Simulation of Flow and Particle Motion in Liquid – Solid Hydrocyclone

Authors: Seyed Roozbeh Pishva, Alireza Aboudi Asl

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In this investigation a hydrocyclone by using for separation particles from fluid in oil and gas, mining and other industries is simulated. Case study is cone – cylindrical and solid - liquid hydrocyclone. The fluid is water and the solid is a type of silis having diameters of 53, 75, 106, 150, 212, 250, and 300 micron. In this investigation CFD method used for analysis flow and movement of particles in hydrocyclone. In this modeling flow is three-dimention, turbulence and RSM model have been used for solving. Particles are three dimensional, spherical and non rotating and for tracking them Lagrangian model is used. The results of this study in addition to analyzing flowfield, obtaining efficiency of hydrocyclone in 5, 7, 12, and 15 percent concentrations and compare them with experimental result that both of them had suitable agreement with each other.

Keywords: hydrocyclone, RSM Model, CFD, copper industry

Procedia PDF Downloads 533
215 The Effect of Bunch in the Branch on Vegetative Characteristics of Pistacia vera

Authors: Alireza Sohrabi, Hamid Mohammadi

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The pistachio fruit is a strategic product in Iran. One of the problems caused the reduction of pistachio proceeds is related to biennial- bearing or alternative bearing. Biennial- bearing is very important and is happened because of the fallen female bloom buds in vintage year. This test was done according to random blocks of 6 orchards in the type of Ahmad Aghaie with 4 iterations. Vegetative properties of branch are investigated. The results are shown that if the bunch numbers are increased, the possibility of falling is increased in bloom buds. The least possibility of falling of bloom buds is specified in trimming of one bunch and has significant difference with other trimming.

Keywords: alternate bearing, pistachio, cluster, bud

Procedia PDF Downloads 386