Arash Kiyoumarsi, Abolfazl Nazari, Mohammad Ataei, Hamid Khademhosseini Beheshti and Rahmat‐Allah Hooshmand
The purpose of this paper is to present a 3D finite element model of the electromagnetic fields in an AC three‐phase electric arc furnace (EAF). The model includes the electrodes…
Abstract
Purpose
The purpose of this paper is to present a 3D finite element model of the electromagnetic fields in an AC three‐phase electric arc furnace (EAF). The model includes the electrodes, arcs, and molten bath.
Design/methodology/approach
The electromagnetic field in terms of time in AC arc is also modeled, utilizing a 3D finite element method (3D FEM). The arc is supposed to be an electro‐thermal unit with electrical power as input and thermal power as output. The average Joule power, calculated during the transient electromagnetic analysis of the AC arc furnace, can be used as a thermal source for the thermal analysis of the inner part of furnace. Then, by attention to different mechanisms of heat transfer in the furnace (convection and radiation from arc to bath, radiation from arc to the inner part of furnace and radiation from the bath to the sidewall and roof panel of the furnace), the temperature distribution in different parts of the furnace is calculated. The thermal model consists of the roof and sidewall panels, electrodes, bath, refractory, and arc. The thermal problem is solved in the steady state for the furnace without slag and with different depths of slag.
Findings
Current density, voltage and magnetic field intensity in the arcs, molten bath and electrodes are predicted as a result of applying the three‐phase AC voltages to the EAF. The temperature distribution in different parts of the furnace is also evaluated as a result of the electromagnetic field analysis.
Research limitations/implications
This paper considers an ideal condition for the AC arc. Non‐linearity of the arc during the melting, which leads to power quality disturbances, is not considered. In most prior researches on the electrical arc furnace, a non‐linear circuit model is usually used for calculation of power quality phenomena distributions. In this paper, the FEM is used instead of non‐linear circuits, and calculated voltage and current densities in the linear arc model. The FEM results directly depend on the physical properties considered for the arc.
Originality/value
Steady‐state arc shapes, based on the Bowman model, are used to calculate and evaluate the geometry of the arc in a real and practical three‐phase AC arc furnace. A new approach to modeling AC arcs is developed, assuming that the instantaneous geometry of the AC arc at any time is constant and is similar to the geometry of a DC arc with the root mean square value of the current waveform of the AC arc. A time‐stepping 3D FEM is utilized to calculate the electromagnetic field in the AC arc as a function of time.
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The purpose of this paper is to assess the possibility of cross-linking silk fabric using citric acid (CA) as the cross-linking agent and nano-TiO2 (NTO) particles as a catalyst…
Abstract
Purpose
The purpose of this paper is to assess the possibility of cross-linking silk fabric using citric acid (CA) as the cross-linking agent and nano-TiO2 (NTO) particles as a catalyst at low temperature and under UV irradiation. This paper also assesses the possibility of treated samples with suitable combinations of CA and NTO to impart multiple functional properties such as self-cleaning and antimicrobial properties.
Design/methodology/approach
In this research, ß-cyclodextrin (ß-CD) grafted onto silk fabric using CA as a crosslinking agent and NTO particles as a catalyst through a pad-dry-cure technique and with UVA irradiation. The effects of different concentrations of CA, ß-CD and NTO particles on some properties of the treated samples are evaluated, and the optimum finishing conditions are obtained. The author also investigated the washing durability of the modified product after ten times of washing.
Findings
The results showed that CA plays the role of a linking agent through an esterification reaction with the hydroxyl groups of both ß-CD and silk fabrics and improves the durability of materials on the textile surface. Also, the silk fabrics treated with CA only were found to have excellent photocatalytic properties and better antibacterial activity than the control sample and the fabrics treated with a mixture of ß-CD/CA.
Originality/value
This study was conducted to achieve multiple functions such as antibacterial and photocatalytic activities, good dry crease recovery angle and wet crease recovery angle behavior without a significant adverse effect on the Yellowness index and tensile properties for treated silk fabrics.
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Abolfazl Zare and Pedram Payvandy
The purpose of this study is the chemical grafting of β-Cyclodextrin (β-CD) onto silk fabrics by the use of butane tetracarboxylic acid (BTCA) as a crosslinking agent and nano-TiO2…
Abstract
Purpose
The purpose of this study is the chemical grafting of β-Cyclodextrin (β-CD) onto silk fabrics by the use of butane tetracarboxylic acid (BTCA) as a crosslinking agent and nano-TiO2 (NTO) as a catalyst. The effects of different parameters involved in this particular process, e.g. β-CD, BTCA and NTO concentrations, are examined using the artificial neural network (ANN). The method is evaluated for its ability to predict certain properties of treated fabrics, including grafting yield, dry crease recovery angle (DCRA) and wet crease recovery angle (WCRA), tensile strength, elongation at break and methylene blue dye absorption.
Design/methodology/approach
This study was conducted to describe the cross-linking of silk with 1,2,3,4-BTCA as a crosslinking agent in a wet state at low temperatures using NTO catalyst to improve the dry and wet wrinkle recovery (DCRA and WCRA) of silk fabrics. An ANN was also used to model and analyze the effects of BTCA, β-CD and NTO concentrations on the grafting percentage and some properties of the treated samples.
Findings
According to the results, the wet and dry wrinkle recovery of the silk fabrics was improved for about 38% and 11%, respectively, as compared to the non-cross-linked fabrics, without significantly affecting the tensile strength retention of the fabrics.
Originality/value
This research model and analyze the effects of BTCA, β-CD and NTO concentrations on the grafting percentage and some properties of the treated samples for the first time.
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Seyed Shahramadin Tavakoli, Afsaneh Mozaffari, Abolfazl Danaei and Ehtesham Rashidi
The purpose of this paper is to explain the effect of the technology acceptance model in the media environment by using the mediating role of artificial intelligence and the cloud…
Abstract
Purpose
The purpose of this paper is to explain the effect of the technology acceptance model in the media environment by using the mediating role of artificial intelligence and the cloud computing approach.
Design/methodology/approach
After reviewing the theoretical foundations, a conceptual model framework and research hypotheses were formed. The statistical population of the study included managers, deputies and experts from the National Iranian Oil Company, and a statistical sample of 368 people was selected by simple random sampling.
Findings
The results of structural equation modelling with PLS 2.0 software show a positive and significant effect on the artificial intelligence variable in the technology acceptance model with the cloud approach. Artificial intelligence has opened a new space in the digital world, especially in the media, so that its profound impact is quite evident and has affected people’s lives.
Originality/value
The acceleration of various technologies has severely challenged the approach of organizations, especially the media. The media environment with word of the technologies of the Industry 4.0, especially cloud computing technology, has changed the ways of accessing and using products and services.
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Abolfazl Gharaei, Seyed Hamid Reza Pasandideh and Alireza Arshadi Khamseh
The main purpose is to minimize the total inventory cost of chain, whereas the stochastic constraints are satisfied. In other words, the goal is to find optimum agreed stockpiles…
Abstract
Purpose
The main purpose is to minimize the total inventory cost of chain, whereas the stochastic constraints are satisfied. In other words, the goal is to find optimum agreed stockpiles and period length for products to minimize the total inventory cost of the chain while the stochastic constraints are fulfilled.
Design/methodology/approach
This paper designs and optimizes an integrated inventory model in a four-echelon supply chain that contains a supplier, a producer, a wholesaler and multiple retailers. All four levels agree with each other to make an integrated inventory system. Products in this model have a multi-stage production process, and the model is bounded by multiple stochastic constraints. The problem model is nonlinear and large. So, the interior point method as an effective algorithm is used for solving the recent convex nonlinear model. Two numerical examples are solved to demonstrate the application of this methodology and to evaluate the performance of the proposed approach.
Findings
The findings showed the model is applicable for real-world supply chain problems in the cases that echelons are going to do executive external integration. Also, the Interior Point algorithm has a satisfactory performance and a high efficiency in terms of optimum solution for solving nonlinear and large models.
Originality/value
The authors designed and optimized the inventory cost in a four-level integrated supply chain in stochastic conditions. The new decision variables, number of chain levels, multi-products, stochastic constraints and multi-stage products in four-level integrated supply chain are other novelties of this paper. The authors provided an efficient algorithm for solving a large-scale and nonlinear model in this research, too.
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The purpose of this study is to introduce a unified framework which integrates knowledge management processes (knowledge creation, sharing, storage and documentation and…
Abstract
Purpose
The purpose of this study is to introduce a unified framework which integrates knowledge management processes (knowledge creation, sharing, storage and documentation and acquisition), innovation capability (product, process, marketing and organizational and organizational performance (operational, financial and product quality). Then empirically test the effect of knowledge management processes (KMP) on innovation capability (IC), the effect of IC on organizational performance (OP) and the impact of KMP on OP through the mediator (IC).
Design/methodology/approach
A questionnaire was designed and addressed to the general managers of the Jordanian companies making up the target population. Statistical techniques employed included confirmatory factor analysis and structural equation modeling (SEM) using AMOS 24 to test the hypotheses.
Findings
The results show that KMP influences IC, IC affects OP and KMP impacts OP through the mediator (IC).
Research limitations/implications
The use of longitudinal data and comparisons with this study would provide further insights that would assist in generalizing knowledge related to the relationships among KMP, IC and Os' P.
Practical implications
If organizations fully comprehend KMP and IC, they would be able to implement them successfully, creating value for their companies and improving OP.
Originality/value
The existing research on KMP and IC is primarily conceptual and descriptive in nature, and empirical research confirming the real impact of KMP when developing IC is lacking. Also. the relationship between innovation capabilities and OP has not been adequately studied. Hence, this study introduces a conceptual framework which integrates KMP, IC and OP and simultaneously empirically tests the relationships among them.