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Hadad M.,Islamic Azad University at Dehaghan | Sadeghi B.,Tarbiat Modares University
Journal of Cleaner Production | Year: 2013

A number of studies have shown that compared to dry machining; MQL technique substantially enhances cutting performance in terms of increasing tool life and improving the quality of the machined parts. But, there have been a few investigations about the influence of process parameters on the results, such as MQL nozzle position and cutting parameters (cutting speed, depth of cut and feed). The current study aims to show through experiment, the effects of the above parameters on turning performance such as machining forces, surface roughness and temperature. Furthermore, this paper presents a new method to calculate average temperatures and the heat partition to the tool, workpiece and chip during MQL turning. This model also can be used for other turning operations such as dry and conventional wet turning processes. In other words, to more accurately predict machining temperatures and heat fluxes, convection heat transfer coefficient of MQL/fluid in the rake and flank faces of the tool have been made to the thermal model. The tool-chip interface temperature of turning AISI 4140 steel in which the oil mist is supplied from both nozzles to the rake and flank faces is approximately 350 C lower than that in dry turning. If the oil mist is supplied only to rake face, the tool temperature is about 200 C lower than that in dry turning. Additionally, in wet turning, the tool-chip interface temperature is about 300 C lower than that in dry turning. © 2013 Elsevier Ltd. All rights reserved. Source

Shabanian Boroujeni F.,Islamic Azad University at Dehaghan
Advances in Environmental Biology | Year: 2013

This paper examines the profitability or lossof charge and discharge automation system of new DRI silos of Mobarakeh Steel Company. In fact, the main objective of this research is to determine the economic quality of project in the automation system of unit (06) of Mobarakeh Steel complex during 2012-2013.In this study, 105 activities along with network transpositions have been studied. Project profitability and loss indicators (ACWP, BCWP and CPI) are calculated according to weight Factor of activities and their percent of completion, and project quality is economically reviewed. Results indicate that the cost performance index in all the activities is smaller than 1, and this shows that the project is already associated with loss and providing ways to minimize loss is inevitable. © 2013 AENSI Publisher All rights reserved. Source

Hadi-Vencheh A.,Islamic Azad University at Khorasgan | Hejazi S.,Islamic Azad University at Dehaghan | Eslaminasab Z.,Islamic Azad University at Khorasgan
Neural Computing and Applications | Year: 2013

In traditional approach, failure mode and effects analysis determines the risk priories of failure modes through the risk priority number which is determined by multiplication of three risk factors namely, failure occurrence (O), failure severity (S) and failure detection ability (D). In this approach, different weights of risk factors were not taken into consideration so that the three risk factors were assumed to have the same weight. This may not be realistic in real applications. In this paper we treat the risk factors as fuzzy variables and evaluate them using fuzzy linguistic terms and fuzzy ratings. As a result, fuzzy risk priority numbers (FRPNs) are proposed for prioritization of failure modes. The FRPNs are defined as fuzzy geometric means of the fuzzy ratings for O, S and D and can be computed using alpha-level sets and linear programming models. A numerical example is provided to examine the results of this model. © 2012 Springer-Verlag London Limited. Source

Shahreza A.R.,Islamic Azad University at Dehaghan | Imani H.,University of Kashan
Energy Conversion and Management | Year: 2015

A novel small scale model of solar chimney was investigated experimentally and numerically. Air flow, heat transfer and flow characteristics were numerically calculated and compared with the experimental results in this paper. Two intensifiers were used to intensify the heat flux radiated by the sun all around the solar chimney in the experimental case. An air tank was located downside the system to increase the absorption of the solar radiation reflected by the intensifiers. RNG k-ε model was chosen to simulate the turbulence and the well-known SIMPLE algorithm was used to solve the coupled velocity and pressure equations. Results show that utilization of intensifiers caused an increase in velocity magnitude in the chimney and consequently more power was generated. The maximum velocity of 5.12 m/s was reached which is remarkable, considering the small size of the SC structure. © 2014 Elsevier Ltd. Source

Allameh M.,University of Isfahan | Zamani M.,University of Isfahan | Davoodi S.M.R.,Islamic Azad University at Dehaghan
Procedia Computer Science | Year: 2011

Today knowledge is considered as a valuable key in competition. Not only it is known as the foundation for stable development, but also it is the source of keeping competitive nature of an organization which is an advantage for the organization. The two fold role of culture, both as the main obstacle and also as the empowering factor in knowledge management activities, makes the importance of this factor double in efficient managing of knowledge management processes. The present article is examining any kind of relationship between different kinds of organizational culture and different dimension of knowledge management. In order to analyze differences between different organizational cultures, the proposed conceptual framework by Comeron and Quinn has been used here. In this article the relationship between four kinds of organizational culture which are group, developmental, hierarchical and logical (market) culture and six dimensions of knowledge management has been examined. This project is applied in nature and the methodology which has been used is correlationnal-descriptive; it is categorized as field study. For analyzing the findings of the research and accepting or rejecting the proposed hypothesis, statistical techniques like step by step regression as well as pearson correlationnal coefficienal has been used. The results indicated that there is a meaningful relationship (about 99%) between different kinds of organizational culture and six dimensions of knowledge management. © 2010 Published by Elsevier Ltd. Source

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