Case studies in industry and services
Md. Fazel Rabbi
Abstract
FMEA (Failure Mode and Effect Analysis) refers to a proactive quality tool that enables the identification and prevention of the potential failure modes of a product or process. However, in executing traditional FMEA, the difficulties such as vague information, relative importance ratings, decisions ...
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FMEA (Failure Mode and Effect Analysis) refers to a proactive quality tool that enables the identification and prevention of the potential failure modes of a product or process. However, in executing traditional FMEA, the difficulties such as vague information, relative importance ratings, decisions on same ratings, and opinion difference among experts arise which reduce the validity of the results. This paper presents a fuzzy logic based FMEA depending on fuzzy IF-THEN rules over traditional FMEA to make it precise and give proper maintenance decision. Here, the Risk Priority Number (RPN) is calculated and compared to the Fuzzy Risk Priority Number (FRPN) to give maintenance decision. Furthermore, the FMEA of Reach Stacker Crane (RST) is presented to demonstrate the proposed Fuzzy FMEA.
Decision analysis and methods
A. Lazar Farokhi
Abstract
Today, the use of risk assessment methods in various industries is expanding, as there are currently more than 70 different types of qualitative and quantitative risk assessment methods in the world. These methods are usually used to identify, control and mitigate the effects of hazards. Organizations ...
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Today, the use of risk assessment methods in various industries is expanding, as there are currently more than 70 different types of qualitative and quantitative risk assessment methods in the world. These methods are usually used to identify, control and mitigate the effects of hazards. Organizations should be able to select one or a combination of several types of risk assessment methods that are explored and studied in this article. In some cases, and for the direction of some sensitive processes, especially in the chemical industry, the production of explosive and combustion products such as the gas transmission company should be analyzed before determining the type of method of all methods and the best approach with regard to financial resources, requires qualitative or quantitative or qualitative and quantitative information, time limits, trained personnel limitations, the type of application of the risk identification method, the advantages, and disadvantages of each of these systems. Generally, acceptable risk levels are different for each organization or individual, depending on financial and economic resources, technological constraints, experienced human resources, discretion and management, and underlying risks such as hidden risks. Organizations usually require a system that, in addition to assessing their activities and processes can help them determine the risk situation, determine risk tolerance criteria, and accurately determine the exact risk of their processes, and ... lead them, depending on the complexity of the activity of each industry, the type of system that can bring them to the target. Is different. In this study, the assessment of the risks of gas Transmission facilities in the 9 regions, has been studied and reviewed. After identifying the various activities of the facility, which included three safety measures for equipment, personal and environmental health, and 28 sub-criteria, from previous studies and surveys, and staff comments. Then, using AHP, the fuzzy questionnaire was completed. Pairwise comparison of criteria and sub-criteria by experts and the use of excel software resulted in the weight of the sub-criteria and the compatibility rate. Then, using the verbal variables, five boost pressure facility with Fuzzy TOPSIS was ranked according to the relevant criteria, and the Rasht boost pressure gained the first rank.
Economics
N. Salehi; H. R. Askarzadeh
Abstract
Although the development of science and technology in the present era has increased human satisfaction from life, it has caused the problems such as environmental pollution and increased demand for energy carriers, especially fossil fuels. Considering that fossil fuels can be exhausted, the most suitable ...
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Although the development of science and technology in the present era has increased human satisfaction from life, it has caused the problems such as environmental pollution and increased demand for energy carriers, especially fossil fuels. Considering that fossil fuels can be exhausted, the most suitable solutions to address the consequences are the use of renewable energy sources to generate electricity. In this paper, using the Particle Cumulative Optimization (PSO) algorithm, we have tried to design an optimal photovoltaic and winding model to supply the power of an area in such a way that the electrical charge generated by this system has the reliable capability and economically viable.
H. Sheikhi
Volume 1, Issue 1 , June 2012, , Pages 42-63
Abstract
Fuzzy multi-objective zero-one linear programming (FMOZOLP) has many applications in various fields such as assembly line balancing, assignment, project portfolio selection and maximal covering location problems. In many of the existing methods for solving FMOZOLP problems, membership degree of different ...
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Fuzzy multi-objective zero-one linear programming (FMOZOLP) has many applications in various fields such as assembly line balancing, assignment, project portfolio selection and maximal covering location problems. In many of the existing methods for solving FMOZOLP problems, membership degree of different points of a fuzzy number is not considered or by performing α-cut, points with membership function more than or equal to α, are included in calculations. However, even in this case, membership degree of these points has no effect on optimal solution. In this paper, in addition to modifying defects and failures of Yu and Li method [1] in solving fuzzy zero-one linear programming problems, we develop a novel approach to solve FMOZOLP problems considering membership degree of coefficients. Finally, an illustrative example for the project portfolio selection is included to compare results obtained by the proposed approach with results obtained by the other fuzzy methods.
A. Jafari; P. Chiniforooshan; F. Zabihi
Volume 2, Issue 1 , February 2013, , Pages 45-62
Abstract
This paper investigates the problem of designing an integrated production-distribution system which supports strategic and tactical decision levels in supply chain management. This overall optimization is achieved using mathematical programming for modeling the supply chain functions such as location, ...
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This paper investigates the problem of designing an integrated production-distribution system which supports strategic and tactical decision levels in supply chain management. This overall optimization is achieved using mathematical programming for modeling the supply chain functions such as location, production, and distribution functions. Our model intends to minimize the total cost including production, location, transportation, and inventory holding costs. In view of the NP-hard nature of the problem, this paper provides a hybrid algorithm incorporates Genetic Algorithm into Lagrangian Relaxation method (namely HLRGA) to update the lagrangian multipliers and improve the performance of LR method. The effectiveness of HLRGA has been investigated by comparing its results with those obtained by CPLEX, hybrid genetic algorithm, and simulated annealing on a set of supply chain network problems with different sizes. Finally, an industrial case demonstrates the feasibility of applying the proposed model and algorithm to the real-world problem in a supply chain network.
Kh. Pichka; B. Ashjari; A. Ziaeifar; P. Nickbeen
Volume 3, Issue 2 , May 2014, , Pages 46-55
Abstract
MDOVRP is a variant of classical VRP, which seeks to find a set of non-depot returning vehicle routes dispatching form several depots. A new integer linear programming model is presented considering limited number of vehicles at each depot. Randomly generated smallsized MDOVRPs are solved for validation ...
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MDOVRP is a variant of classical VRP, which seeks to find a set of non-depot returning vehicle routes dispatching form several depots. A new integer linear programming model is presented considering limited number of vehicles at each depot. Randomly generated smallsized MDOVRPs are solved for validation and verification of the proposed model. Due to the complexity of the problem, a simulated annealing algorithm (SA) is developed for medium and large-sized MDVRPs’ benchmarks.
R. Golestaneh; A. Jafari; M. Khalilzadeh; H. Karimi
Volume 2, Issue 3 , September 2013, , Pages 47-57
Abstract
In this paper, we study a resource-constrained project-scheduling problem in which the objective is minimizing total Resource Tardiness Penalty Costs. We assume renewable resources that are limited in number, are restricted to very expensive equipment and machines, therefore they are rented and used ...
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In this paper, we study a resource-constrained project-scheduling problem in which the objective is minimizing total Resource Tardiness Penalty Costs. We assume renewable resources that are limited in number, are restricted to very expensive equipment and machines, therefore they are rented and used in other projects, and are not available in all project periods. In other words, there exists a predefined ready-date as well as a due date for each renewable resource type. In this way, no resource is utilized before its ready date. Nevertheless, resources are allowed to be used after their due date by paying penalty costs depending on the resource type. The objective is to minimize the costs of renewable resource usages. We formulated and mathematically modeled this problem as an integer-Linear programming model. Since our problem is NP-hard and also exact methods are only applicable in small scale, therefore metaheuristic methods are practical approaches for this problem; this means that metaheuristics are better for this problem. In order to authenticate the model and solution algorithm in small scale, we consider a network with low activity, and then solve the model of this network with both exact algorithms and SA-GA-TS metaheuristic algorithms. For more activities, as well as getting closer to the real world, we present a Simulated Annealing Algorithm to solve this problem. In order to examine the performance of this algorithm, data that had been derived from studied literature were used, and their answers were compared with Genetic Algorithm (GA) and Tabu Search Algorithm (TS). Results show that in average, quality of SA answers was better than those of the GA and TS algorithms. In addition, we use relaxation method to achieve an even higher validation for the SA algorithm. Finally all results in this paper indicate that both model and solution algorithm have high validity.
M. Rabbani; H. Yousefnejad; H. Rafiei
Volume 3, Issue 1 , May 2014, , Pages 49-54
Abstract
This article attempts to cope with one of the most vital strategic decisions in the supply chain design in terms of manufacturing context. The issues of finding the best position of Customer Order Decoupling Point (CODP) in a production line have been taken into consideration by many researchers in recent ...
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This article attempts to cope with one of the most vital strategic decisions in the supply chain design in terms of manufacturing context. The issues of finding the best position of Customer Order Decoupling Point (CODP) in a production line have been taken into consideration by many researchers in recent years, but locating CODP along a supply chain has not yet been completely investigated. Here we present a novel combined DEA/AHP method to tackle the problem of positioning CODP in a supply chain. Then in order to prove the applicability of the proposed structure in a real case, the model is implemented in a food processing supply chain.
Systems and service modeling and simulation
H. Amin-Tahmasbi; M. Hami
Abstract
In today’s competitive business environment, supply chain performance is one of the most critical issues in the various industries; there is much argumentation about the fact that supply chain performance is the basis of the supply chain management efficiency. In this regard, the distribution sector ...
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In today’s competitive business environment, supply chain performance is one of the most critical issues in the various industries; there is much argumentation about the fact that supply chain performance is the basis of the supply chain management efficiency. In this regard, the distribution sector is the most important part of the supply chain. Due to the pulse of a company is in the hands of its sales and distribution department. This article proposes a new mixed integrated linear programming model MILP for scheduling distribution channel membership based on capillary marketing by considering staffs experiences at Pak's pasteurized dairy in one month. The purpose of this study is to reduce the costs of the company along with the increase in sales. Constraints affecting target functions such as minimum sales per employee and maximum overtime days are also considered. The computational experiment by GAMS software demonstrates the effectiveness of the model in reaching its objectives.
M. Ashoori; M.J. Tarokh
Volume 3, Issue 4 , December 2014, , Pages 57-69
Abstract
Risk is a destructive phenomenon, which is an integral part of any business. Process mining is a form of a business process analysis based on the recorded process data by information systems, whose its aim is to discover process, control, data, organizational and social structures from event logs. A ...
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Risk is a destructive phenomenon, which is an integral part of any business. Process mining is a form of a business process analysis based on the recorded process data by information systems, whose its aim is to discover process, control, data, organizational and social structures from event logs. A process mining project methodology (PMPM) is considered as especially useful in the process mining project, which a comprehensive methodology that can be used as an efficient and effective approach for applying process mining in practice. This methodology made us sure that all important activities are performed and prevented of redundant work. This paper utilizes the PMPM for risk reduction to increase the organization agility against competitors and obtain the more market share. Evaluating the case study results with trace alignment method confirms expert confirmations. Trace alignment shows interesting patterns and provide better insight on process executions.
B. Kheyri; M. Mardi; Z. Mahzoun
Volume 1, Issue 2 , July 2012, , Pages 58-71
Abstract
Due to recent advancements in information technology and communication, Electronic Customer Relationship Management has drawn the attention of many firms to achieve competitive advantages. Despite the increasing importance given to understanding their customers better, organizations find inconsistencies ...
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Due to recent advancements in information technology and communication, Electronic Customer Relationship Management has drawn the attention of many firms to achieve competitive advantages. Despite the increasing importance given to understanding their customers better, organizations find inconsistencies between information technology and the existing marketing strategies, when they come to decide upon implementing e-CRM, as well as lack of theoretical backgrounds for developing success measures in this domain. Therefore, this study deals with describing a model for successful e-CRM, using variables such as customer information quality, technology system, efficiency, customer satisfaction, and profitability. These constructs cover most of variables and concepts presented yet in theories of successful information systems and views about customer satisfaction. Ample empirical evidence is gained through this research from analyzing the outcomes of 309 questionnaires distributed to employees and customers of some automobile manufacturers having established e-CRM. The results of this study may open up new ways of applying concepts and relationship-oriented marketing models and e-CRM in automobile industry.
S. Ghayebloo; M.J. Tarokh; M. Abedzadeh
Volume 2, Issue 4 , December 2013, , Pages 58-71
Abstract
This paper aims to study the impact of product greenness and part reliability on reverse supply chain network through green supplier selection and disassembly of products. It proposes a bi-objective mathematical modeling for a closed-loop supply chain network considering green supplier selection and ...
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This paper aims to study the impact of product greenness and part reliability on reverse supply chain network through green supplier selection and disassembly of products. It proposes a bi-objective mathematical modeling for a closed-loop supply chain network considering green supplier selection and disassembly of products to trade-off profit and greenness. To our knowledge, this study is the first paper which considers the greenness of products in part/components level. So, some important issues such as part reliability, part greenness and inventory management of new and recovered parts are included into the model. Part reliability and part greenness are considered as green criteria in green supplier selection stage. Product greenness is defined according to design for disassembly level. Better design for disassembly means more greenness level for the products and better yield of parts at the disassembly stage. Green parts are made of highly recyclable materials. According to the part greenness and part reliability, some scenarios are defined. The greenness level of product is chosen by the model. ε-constraint method is applied to solve the model. A set of Pareto-optimal solution is obtained by using ε-constraint method to show the trade-off between the profit and greenness objectives. The results showed the efficiency of the model.
M.H.M.A. Jahromi; R. Jafari; A. Shamsi
Volume 1, Issue 3 , December 2012, , Pages 60-68
Abstract
Operations assignment to feasible and suitable machine-tool combination affects the total production costs and selecting the best combinations is important for these systems, this is one of the significant problems in flexible manufacturing systems (FMSs). In this paper, minimizing the machining cost, ...
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Operations assignment to feasible and suitable machine-tool combination affects the total production costs and selecting the best combinations is important for these systems, this is one of the significant problems in flexible manufacturing systems (FMSs). In this paper, minimizing the machining cost, setup cost and material handling cost for the given multi-objective problem is considered. Also, this problem is solved with a grouping genetic algorithm and the associated results are presented.
B. Farhang Moghaddam; A.A. Fatahi
Volume 2, Issue 2 , June 2013, , Pages 61-69
Abstract
A very effective and strategic factor in the success of transportation projects is the process of selecting an execution system (delivery option). This is the reason why identifying the challenges and selecting an appropriate execution system in transportation projects are quite important; proper selecting ...
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A very effective and strategic factor in the success of transportation projects is the process of selecting an execution system (delivery option). This is the reason why identifying the challenges and selecting an appropriate execution system in transportation projects are quite important; proper selecting will lead to proper progress in the execution of the projects of this sector which is somehow the basis for the country’s development. In this paper, using extensive field studies, the most important affecting factors of the existing main execution systems in Iran, including Design-Bid-Build (DBB), Design-Build (DB) and Construction Management (CM), in road, railway, and freeway projects were determined. Then, using the Analytic Hierarchy Process (AHP) and the Expert Choice software, the appropriate execution system for each of such projects were identified and grouped
Decision analysis and methods
M. Barzegar; R. Ehtesham Rasi; A. H. Niknamfar
Abstract
Todays, some challenges such as soil, water and air pollution, and severe health hazards to humanity are the results of growing manufacturer in the real world. These challenges are so-called posing risk for sustainable development of the planet. In this matter, the need of achieving higher economic prosperity, ...
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Todays, some challenges such as soil, water and air pollution, and severe health hazards to humanity are the results of growing manufacturer in the real world. These challenges are so-called posing risk for sustainable development of the planet. In this matter, the need of achieving higher economic prosperity, along with the least environmental impact has led to a new manufacturing paradigm so-called Green Manufacturing (GM). In this way, Small and Medium-sized Enterprises (SMEs) in Iran with ISO 9001 and ISO 14001 certification, and Just-In-Time inventory control, which make up 99.8 percent of all businesses, are responsible for 70 percent of all industrial pollution. In this paper, we explore the drivers of the GM of SMEs’ environmental processes in field of the industrial chemistry and their impacts on GM. Unfortunately, there is no proper work considering a wide range of drivers of GM in an industrial chemistry. We evaluate 500 Iran SMEs in the field on industrial chemistry, and select the Tage Company as a case study for this purpose considering its Greenhouse Gas Emission (GHG). This paper aims to gather the common drivers of GM from several sources on a case study in Tage Iran Company, as well as to analyze them by utilizing Analytical Network Process (ANP) in an uncertain environment. To tackle this uncertainty, the fuzzy ANP is utilized to prioritize the barriers to GM based on environmental, social, and economic perspectives. Finally, based on the obtained drivers, the fuzzy ANP identifies essential critical driver and the priority of drivers by utilizing a pair-wise comparison
Case studies in industry and services
A. Devnath; Md. S. Islam; S. Rashid; E. Islam
Abstract
Selecting the right lean tool is one of the most challenging tasks for decision-makers. This research represents an integration of two methods, Quality Function Deployment (QFD) and TOPSIS, to evaluate and prioritize the lean tools. The aim of this research is to propose an integrated QFD-TOPSIS method ...
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Selecting the right lean tool is one of the most challenging tasks for decision-makers. This research represents an integration of two methods, Quality Function Deployment (QFD) and TOPSIS, to evaluate and prioritize the lean tools. The aim of this research is to propose an integrated QFD-TOPSIS method for finding and ranking the major wastes on a production floor and also prioritize lean tools for eliminating them. The proposed model consists of House Of Quality (HOQ) to identify major waste signs which transform them into seven wastes. A set of relative weights of the wastes were then determined which were input in the TOPSIS method to prioritize suitable lean tools.
F Hosseinzadeh Lotfi; M. Piri
Volume 3, Issue 3 , September 2014, , Pages 69-74
Abstract
Data Envelopment Analysis (DEA) is a nonparametric method for measuring the efficiency of Decision Making Units (DMUs) which was first introduced by Charnes, Cooper and Rhodes in1978 as the CCR model .One of the most important topics in management science is determining the efficiency of DMUs. DEA technique ...
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Data Envelopment Analysis (DEA) is a nonparametric method for measuring the efficiency of Decision Making Units (DMUs) which was first introduced by Charnes, Cooper and Rhodes in1978 as the CCR model .One of the most important topics in management science is determining the efficiency of DMUs. DEA technique is employed for this purpose. In many DEA models, the best performance of a DMU is indicated by an efficiency score of one. There is often more than one DMU with this efficiency score. To rank and compare efficient units, many methods have been introduced. Moreover, the main assumption in all DEA models was that all input and output values are positive, but practically, we encounter many cases that violate this term and we ultimately have negative inputs and outputs.
Forecasting, production planning, and control
H. Nasiri; K. Taghizadeh; B. Amiri; V. Shaghaghi Shahri
Abstract
Economic cycles are referred as repeatable movement of economic indicators with different domain and duration. Detection of these cycles may help in forecasting the contraction period or expansions of important parts of the economy specifically industry. In this regard, many economist and researchers ...
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Economic cycles are referred as repeatable movement of economic indicators with different domain and duration. Detection of these cycles may help in forecasting the contraction period or expansions of important parts of the economy specifically industry. In this regard, many economist and researchers have focused on composite leading indicators which are growing in terms of diversity of econometric methods. This paper studies 13 macro economical time series in order to develop the best composite indicator, reflecting business cycles of Iran’s industry. Number of established licenses, production index of large industrial units, producer price index and import value index are the chosen variables that make the proposed composite leading indicator. The result of comparison between composite leading indicator and value added time series in the studied period (1997 up to 2012) showed a good correlation between the fluctuations of composite indicators and value added of industry. The result also showed that the proposed leading indicator has the ability to predict the business cycle for maximum 4 and minimum 1 period ahead and in average the forecasted period is equal to 3.2 seasons.
Supply chain management
S. Aliari-Kardehdeh; S. Ayazi-Yazdi; R. Tavakkoli-Moghaddam; H. Farrokhi-Asl
Abstract
This paper considers a dynamic pricing decision problem, in which two different manufacturers compete to distribute substitutable products through a single retailer under two presented scenarios. In the first scenario, the pricing policy is determined via a centralized decision-making, while the second ...
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This paper considers a dynamic pricing decision problem, in which two different manufacturers compete to distribute substitutable products through a single retailer under two presented scenarios. In the first scenario, the pricing policy is determined via a centralized decision-making, while the second scenario manages the policy in a decentralized one. Utilizing the game-theory-based modeling approaches, the pricing decision problem is achieved under with two different structures. Numerical experiments are also given to examine the effects of the presented scenarios and provide further managerial insights on the solutions.
Fuzzy optimization
S. H. Mirzaei; A. Salehi
Abstract
In many real applications, the data of production processes cannot be precisely measured. Hence the input and output of Decision Making Units (DMUs) in Data Envelopment Analysis (DEA) may be imprecise or fuzzy-numbered. In original DEA models, inputs and outputs are measured by exact values on a ratio ...
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In many real applications, the data of production processes cannot be precisely measured. Hence the input and output of Decision Making Units (DMUs) in Data Envelopment Analysis (DEA) may be imprecise or fuzzy-numbered. In original DEA models, inputs and outputs are measured by exact values on a ratio scale, therefore conventional DEA can't easily measure the performance of DMUs and rank them. The researchers have introduced mane deferent model for ranking DMUs by fuzzy number. In this paper, we proposed a new method by using the Tchebycheff norm for ranking DMUs with fuzzy data. We explain our method by numerical example with the triangular fuzzy number.
Facility location, layout, design, and materials handling
H. Jafari; M. Ehsanifar; A. Sheykhan
Abstract
The Quadratic Assignment Problem (QAP) is one of the problems of combinatorial optimization belonging to the NP-hard problems’ class and has a wide application in the placement of facilities. Thus far, many efforts have been made to solve this problem and countless algorithms have been developed ...
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The Quadratic Assignment Problem (QAP) is one of the problems of combinatorial optimization belonging to the NP-hard problems’ class and has a wide application in the placement of facilities. Thus far, many efforts have been made to solve this problem and countless algorithms have been developed to achieve the optimal solutions; one of which is the Simulated Annealing (SA) algorithm. This paper aims at finding a suitable layout for the facilities of an industrial workshop by using a Developed Simulated Annealing (DSA) method.
Human factors, ergonomics, and safety
L. Noshin; H. Sen Gupta; Md. G. Kibria
Abstract
The world of ergonomic evaluation considerate the human biomechanics and anthropometric measurement an integral part of product design and development work. In this paper, we have given an attempt to design an ergonomically fitted office chair suitable for Bangladeshi people. In this paper, the anthropometric ...
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The world of ergonomic evaluation considerate the human biomechanics and anthropometric measurement an integral part of product design and development work. In this paper, we have given an attempt to design an ergonomically fitted office chair suitable for Bangladeshi people. In this paper, the anthropometric data analysis has been done in order to determine the necessary dimensions suitable for the office chair. Lastly, an ergonomically fitted office chair is designed based on this anthropometric data analysis. The concept of the paper is to focus on the dimensional changes that the Bangladeshi people need for their comfort in the ergonomic office chair. The structural difference in different regions makes us inspired to think about the office chair ergonomics for Bangladeshi people. In short, this paper reflects the entire process of designing an ergonomic office chair suitable for them.
Case studies in industry and services
A. O Adeniran; K. T. Gbadamosi
Abstract
This study examines some concessioned airports in the developed countries and their operational performance level with a view to identifying the positive impact of concessioning on their growth, development and operational performance. The ultimate goal of the study is to provide basis for adapting the ...
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This study examines some concessioned airports in the developed countries and their operational performance level with a view to identifying the positive impact of concessioning on their growth, development and operational performance. The ultimate goal of the study is to provide basis for adapting the experience from lessons learnt to Nigeria’s airports as a strategy for realization of airport operational efficiency. The study advocated for the concessioning of two principal airports in Nigeria because of their potentials to enhancing the application of the experience learnt from lessons on concessioning in the developed countries. Data obtained from relevant Government Institutions and Agencies in Nigeria were analyzed using descriptive statistics. It was concluded that Lagos and Abuja International Airport are the two major airports in Nigeria that can be privatized or concessioned in order to improving their level of efficiency. Happenings around the world have shown the efficacy of Government disengagement in running business through the policy of concessioning and privatization. Airport concessioning and privatization has been considered as a major tool to enhance airport efficiency as witnessed in the developed countries. Airport concessioning has the capacity to enhance efficiency of airport operation; reduce cost of airport services to stakeholders; decrease cost to the government for the support of airport sector; and attract private sector participation to free public resources for public services.
S. Q. Weng
Abstract
In recent years, the research of the fixed point theorem is a hot topic all the time. In this paper, we propose the notion of new mapping, that is, a general LW-type cyclic mapping, in a complete b-metric-like spaces. Then, we obtain the existence and uniqueness theorem of its fixed point. Moreover, ...
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In recent years, the research of the fixed point theorem is a hot topic all the time. In this paper, we propose the notion of new mapping, that is, a general LW-type cyclic mapping, in a complete b-metric-like spaces. Then, we obtain the existence and uniqueness theorem of its fixed point. Moreover, we give an example to illustrate the main results of this paper.
Operations Research
M. A. Abdel Khalek; F. I. El-Hosiny; K. A. Selim; I. Osama
Abstract
A novel continuous electroflotation cell, about 0.6 liter volume capacity, using aluminum electrodes was designed for oil produced water treatment. The treating performance of a novel continuous electroflotation cell for oil produced water was investigated. The pH, current density, and feed water flow ...
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A novel continuous electroflotation cell, about 0.6 liter volume capacity, using aluminum electrodes was designed for oil produced water treatment. The treating performance of a novel continuous electroflotation cell for oil produced water was investigated. The pH, current density, and feed water flow rate as affecting parameters of electroflotation process were studied. The results show that the removal efficiency decreased with increasing feed flow rate. However, it increased with increasing current density. The AC current was preferred because DC current causes passivation of the anode with time. The maximum removal for all types of pollutants is achieved at pH6. The designed electroflotation cell could remove different constituents of oil produced water with range 87.5 - 99.5 % at 25°C, 5V, pH7 and AC current density of 80A/m2 through a bipolar connection of the 8 electrodes with feed water flow rate of 60ml/min (3.6l/hr). The energy consumption was about 1.38Kwh/m3 and the operating cost (cost/m3) was about 0.3US$/m3 for the produced water treatment.
