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.
Fuzzy optimization
Mohammad Hossein Kabgani
Abstract
Selecting appropriate locations for Municipal Solid Waste (MSW) management facilities, such as landfills, is an important issue in rapidly developing regions. Multiple alternatives and evaluation attributes need to be analyzed to finalize the locations of these facilities. The selection of a landfill ...
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Selecting appropriate locations for Municipal Solid Waste (MSW) management facilities, such as landfills, is an important issue in rapidly developing regions. Multiple alternatives and evaluation attributes need to be analyzed to finalize the locations of these facilities. The selection of a landfill site in an urban area is a critical issue due to the involvement of many parameters. The decisive parameters are environmental, economic, and social, some of them conflicting, making landfill site selection a tedious and complex process. Multi Attribute Decision Making (MADM) approaches are found to be very effective for ranking several potential locations and, hence, selecting the best among them based on the identified attributes. Therefore, this study presents a two-stage MADM model that also accounts for all possible combinations of locations. This study evaluates economic, environmental, social, and technical attributes based on realistic conditions. Based on the results, 15 attributes are first identified through a comprehensive literature review and with the help of municipal officials during field surveys. These attributes are categorized into four types, i.e., economic, technical, environmental, and social, based on their respective propensity.In the second step, a statistical analysis questionnaire was distributed among the study population, and Cronbach's alpha was explained for all four main factors of the study. Therefore, in the last step, the rank of all research variables was calculated using the Nonlinear analysis method. Based on the results of this study, the technical variable was ranked first, the economic variable was ranked second, and the environmental and social variable was ranked third. This article has three theoretical, practical, and technical contributions. Also, this article provides a clear explanation of the theoretical contribution related to the accumulated knowledge, both in the introduction and theoretical background sections of the article. Therefore, studying the past research describes a relatively complete background of the planned theoretical contributions of this article compared to the previous research. Therefore, the theoretical contribution of this article solves the scientific gap about effective indicators for determining the location of waste disposal. From the point of view of practical contribution, this article presents practical concepts related to managers and experts and has practical suggestions presented in the conclusion section. Also, the technical contribution of this article is presented by combining fuzzy logic and Nonlinear mathematical programming.
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.
Management Sciences
A. Adeniran; S. O. Fadare
Abstract
The study examines the relationship between passengers’ satisfaction and service quality in MMIA. The sample size for the study is a total of three hundred and eighty-four (384), meanwhile, 58.3 percent of response rate was valid for data analysis. 49.1 percent valid questionnaire responses were ...
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The study examines the relationship between passengers’ satisfaction and service quality in MMIA. The sample size for the study is a total of three hundred and eighty-four (384), meanwhile, 58.3 percent of response rate was valid for data analysis. 49.1 percent valid questionnaire responses were obtained from the international terminal while 50.9 percent valid questionnaire responses were obtained from the domestic terminal. From the survey, the majority of the respondent was male representing 62.5 percent. From correlation analysis, about 71.1 percent of all service dimensions give a positive and very strong correlation, while about 18.4 percent of all service dimensions give a positive and strong correlation, also about 7.9 percent of all service dimensions give a positive and weak correlation, and about 2.6 percent of all service dimensions give a positive and very weak correlation. Efficiency of available public transport options is the only service with a very weak correlation. The study also revealed that there is a relationship between passengers’ satisfaction and service quality at P.value less than 0.05. This signifies that service quality leads to passengers’ satisfaction. It is therefore suggested that airport services should be quality so as to have a corresponding effect on high passengers’ satisfaction.
Data Envelopment Analysis, DEA
F. Z. Montazeri
Abstract
One of the best techniques for evaluating the performance of organizations is data envelopment analysis. Data Envelopment Analysis (DEA) is a non-parametric method for evaluating the performance of decision-making units (DMUs) that recognizes the relative performance of DMUs based on mathematical programming. ...
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One of the best techniques for evaluating the performance of organizations is data envelopment analysis. Data Envelopment Analysis (DEA) is a non-parametric method for evaluating the performance of decision-making units (DMUs) that recognizes the relative performance of DMUs based on mathematical programming. The classic DEA model was initially formulated for optimal inputs and outputs, But in real-world problems, the values observed from input and output data are often ambiguous and random. In fact, decision-makers may be faced with a specific hybrid environment where there are fuzziness and randomness in the problem. To overcome this problem, data envelopment analysis models in the random fuzzy environment have been proposed. Although the DEA has many advantages, one of the disadvantages of this method is that the classic DEA does not actually give us a definitive conclusion and does not allow random changes in input and output. In this research data envelopment analysis models in fuzzy random environments is reviewed.
Inventory, logistics, and transportation
A. Adetayo Adeniran; K. Olufunto Adedotun
Abstract
Trend analysis of domestic air travel demand in Nigeria was examined based on yearly passenger demand from 2010 to 2017. Ordinary Least Square (OLS) regression was used to forecast for twelve years (2018 to 2030) demand for domestic air passenger travel in Nigeria. The demand for domestic air passenger ...
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Trend analysis of domestic air travel demand in Nigeria was examined based on yearly passenger demand from 2010 to 2017. Ordinary Least Square (OLS) regression was used to forecast for twelve years (2018 to 2030) demand for domestic air passenger travel in Nigeria. The demand for domestic air passenger in Nigeria from year 2010 to 2017 was compared with the forecast. There seems to be periods of fluctuations in the demand for domestic air passenger travel in Nigeria from year 2010 to 2017 which are expected to have effect on the forecast of domestic air travel. Calculation and computation reveals that the coefficient of determination R2 is 0.203 which signifies a high error term such that the explanation level is very low; hence the prediction or forecast is unreliable. Despite the decline in the forecast of domestic air passenger demand in the future, and the fact that the forecast is unreliable, hence inconclusive as shown from the coefficient of determination, government agencies should be sensitive to the forecast and try to adopt new policies and strategies that will improve the demand for domestic air passenger travel in Nigeria.
Engineering Optimization
S. Aluvihara; J. K. Premachandra
Abstract
Crude oil is a predominant natural resource and also it causes the metallic corrosion in the industry of crude oil refining due to some corrosive properties of crude oils. In the current research, it is expected to investigate the effect of such compounds of crude oils on the rate of corrosion of seven ...
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Crude oil is a predominant natural resource and also it causes the metallic corrosion in the industry of crude oil refining due to some corrosive properties of crude oils. In the current research, it is expected to investigate the effect of such compounds of crude oils on the rate of corrosion of seven different types of ferrous metals which are frequently used in the crude oil refining industries. The sulfur content, salt content, acidity, and mercaptans content of each crude oil are determined in order to use XRF analyzer, salt analyzer, and titration methods. A set of equal size metal pieces are immersed in both crude oils separately for 15, 30, and 45 days and their corrosion rates are determined by using relative weight loss after these time periods while observing the corroded metal surface under the optical microscope, and the dissolved metal concentration in each crude oil sample is tested by the AAS. The hardness of each metal piece is tested before and after the immersion in crude oil with the aid of Vicker’s hardness tester. It is found that a higher amount of sulfur, acidity, and mercaptans and lower amount of salt present in Das blend than Murban. We have found there is some significant rate of corrosion from most of the metals and higher amount of dissolved metallic concentration in samples of both crude oils with respect to those metals. It is observed that there is a slight reduction in hardness of all metal pieces due to the corrosion.
Other
A. Y. Ali
Abstract
The aim of this paper is to propose a Six Sigma-DMAIC and food waste hierarchy-based framework that can be successfully implemented by Ethiopian University canteen managers to reduce food waste in a sustainable way. The importance of this research is twofold. First, the Six Sigma-DMAIC methodology is ...
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The aim of this paper is to propose a Six Sigma-DMAIC and food waste hierarchy-based framework that can be successfully implemented by Ethiopian University canteen managers to reduce food waste in a sustainable way. The importance of this research is twofold. First, the Six Sigma-DMAIC methodology is used to evaluate and improve the process to prevent food surplus and waste in the canteen. Second, other waste hierarchy options will be used to mitigate food waste problem in a sustainable way. This has a positive social, environmental, and economic implications.
Other
R. V. M. S. S. Kiran Kumar; G. Vindo Kumar; S. V. K. Verma
Abstract
This paper aimed to model and analyze the unsteady hydromagnetic boundary layer stagnation point nanofluid flow over a non-linear stretching surface through porous medium with variable wall thickness. The effects of radiation, dissipation, and slip velocity are taken into account. The formulation of ...
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This paper aimed to model and analyze the unsteady hydromagnetic boundary layer stagnation point nanofluid flow over a non-linear stretching surface through porous medium with variable wall thickness. The effects of radiation, dissipation, and slip velocity are taken into account. The formulation of the problem is made through Buongiorno’s model, which involves the aspects of thermophoresis and Brownian motion. The set of governing non-linear Ordinary Differential Equations (ODE’s) are solved numerically by using boundary value problem default solver in MATLAB bvp4c package. The impact of different flow quantities on fluid velocity, temperature, and nanoparticle concentration are analyzed and examined through graphs. The physical parameters like friction factor coefficient , rates of heat transfer , and nanoparticle friction are derived and presented through tables. It is found that the wall thickness parameter depreciates the nanofluid velocity for and accelerates when . Also, the unsteadiness parameter shows a significant effect on the stagnation point flow.
Mathematical modelling
H. Saberi Najafi; A. Yaghoubi
Abstract
In this paper we construct Non-Standard finite difference schemes (NSFD) for numerical solution of nonlinear Lane-Emden type equations which are nonlinear ordinary dierential equations on semi-infinite domain. They are categorized as singular initial value problems. This equation describes a variety ...
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In this paper we construct Non-Standard finite difference schemes (NSFD) for numerical solution of nonlinear Lane-Emden type equations which are nonlinear ordinary dierential equations on semi-infinite domain. They are categorized as singular initial value problems. This equation describes a variety of phenomena in theoretical physics and astrophysics. The presented schemes are obtained by using the Non-Standard finite difference method. The use of NSFD method and its approximations play an important role for the formation of stable numerical methods. The main advantage of the schemes is that the algorithm is very simple and very easy to implement. Thus, this method may be applied as a simple and accurate solver for ODEs and PDEs and it can also be utilized as an accurate algorithm to solve linear and nonlinear equations arising in physics and other fields of applied mathematics. Illustrative examples have been discussed to demonstrate validity and applicability of the technique and the results have been compared with the exact solutions.
Other
R. V M S S Kiran Kumar; T. Chalapathi
Abstract
Let (Zn, +) be a finite group of integers modulo n and Dn a non-empty subset of Zn containing proper devisors of n. In this paper, we have introduced the difference divisor graph Diff (Zn, Dn) associated with Zn whose vertices coincide with Zn such that two distinct vertices are adjacent if and ...
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Let (Zn, +) be a finite group of integers modulo n and Dn a non-empty subset of Zn containing proper devisors of n. In this paper, we have introduced the difference divisor graph Diff (Zn, Dn) associated with Zn whose vertices coincide with Zn such that two distinct vertices are adjacent if and only if either a-b belongs to Dn or b-a belongs to Dn . We have investigated its algebraic and graph theoretic properties. Further, we have proved that the difference divisor graph Diff (Zn, Dn) is not a Cayley graph.
Mathematical modelling
G. C. Sankad; P. S. Nagathan
Abstract
Incompressible Jeffrey fluid under peristalsis is considered into permeable conduit. Magnetic effect and slip effect are studied for this channel in the existence of wall slip and heat transfer. Time average velocity, heat transfer coefficient and temperature are obtained analytically underneath the ...
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Incompressible Jeffrey fluid under peristalsis is considered into permeable conduit. Magnetic effect and slip effect are studied for this channel in the existence of wall slip and heat transfer. Time average velocity, heat transfer coefficient and temperature are obtained analytically underneath the presumption of large wavelength approximation and also small Reynolds number. Effects of magnetic number, slip parameter, elasticity parameters and Brinkman number on coefficient of heat transfer and temperature field are graphically discussed. It is observed that in the case of temperature distribution the flow intensity enhances with rise in the Darcy number, while it reduces with enhancement in the Brinkman number and slip parameter.
H. Abd El-Wahed Khalifa
Abstract
This paper aims to study the multi-objective transportation problem with fuzzy parameters. These fuzzy parameters represented as (α, β) interval-valued fuzzy numbers instead of the normal fuzzy numbers. Using the signed distance ranking, the problem converted into the corresponding crisp ...
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This paper aims to study the multi-objective transportation problem with fuzzy parameters. These fuzzy parameters represented as (α, β) interval-valued fuzzy numbers instead of the normal fuzzy numbers. Using the signed distance ranking, the problem converted into the corresponding crisp multi-objective transportation problem. Then, the solution method introduced by [8] for solving the problem is applied. This method provides the ideal and the set of all fuzzy (α, β) efficient solutions. The advantage of this method is more flexible than the standard multi-objective transportation problem, where it allows the decision maker to choose the (α, β) levels of fuzzy numbers he is willing. A numerical example to illustrate the utility, effectiveness, and applicability of the method is given.
Case studies in industry and services
Jamal Aghayari; Changiz Valmohammadi; Mahmood Alborzi
Abstract
The corporate landscape is highly affected by two market factors, namely digitalization and sustainability. These two driving forces have been the topic of several studies on how they change management methods, businesses, and society in general. However, the point that these two trends meet each other ...
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The corporate landscape is highly affected by two market factors, namely digitalization and sustainability. These two driving forces have been the topic of several studies on how they change management methods, businesses, and society in general. However, the point that these two trends meet each other has been mostly neglected by research studies. Modern organizations and corporations are dealing with the adopting digital transformation issue as a new strategic paradigm. The present study attempts to elaborate on the relationship between digital transformation and sustainability. Therefore, through an in-depth review of the relevant literature, critical factors and their indicators were determined, and based on the proposed conceptual model, six hypotheses were developed. Then, a questionnaire was designed and distributed among 120 Iranian experts, managers, and consultants, and 97 complete questionnaires were returned. Reliability, Content Validity Ratio (CVR), and Content Validity Index (CVI) of the questionnaire were calculated, and the hypotheses were tested through Structural Equation Modeling (SEM) using SmartPLS Software. The results showed that digital transformation significantly affected an organization's sustainability aspects through operation, customer, business model, technology, workforce, and collaboration. Digital transformation and sustainability should constitute integral parts of organizational strategy. Considering that business practices affect the environment, society, and economy, digital transformation can influence the business sustainability. Digital technologies transform markets and create novel paradigms in the industry. In addition, they present new solutions to organizations to cope with sustainability issues. Due to this importance for organizations as consumers and other stakeholders, they are sensitive to the effects of business on brand value, revenues, and company valuation.
Numerical Analysis
F. Rahpeymaii; M. Kimiaei
Abstract
In this paper, we introduce a new adaptive trust-region approach to solve systems of nonlinear equations. In order to improve the efficiency of adaptive radius strategy proposed by Esmaeili and Kimiaei [8], Barzilai Borwein technique (BB) [3] with low memory is used which can truly control the trust-region ...
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In this paper, we introduce a new adaptive trust-region approach to solve systems of nonlinear equations. In order to improve the efficiency of adaptive radius strategy proposed by Esmaeili and Kimiaei [8], Barzilai Borwein technique (BB) [3] with low memory is used which can truly control the trust-region radius. In addition, the global convergence of the new approach is proved. Computational experience suggests that the new approach is more effective in practice in comparison with other adaptive trust-region algorithms.
Banking industry
S. Kumar-Das
Abstract
Because of uncertainty in the real life applications, reaching to the optimal solution is always time consuming and even sometimes impossible. In order to overcome these limitations the fuzzy set theory is introduced to handle it but not only incomplete information but also indeterminate and inconsistent ...
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Because of uncertainty in the real life applications, reaching to the optimal solution is always time consuming and even sometimes impossible. In order to overcome these limitations the fuzzy set theory is introduced to handle it but not only incomplete information but also indeterminate and inconsistent information which is common in real life conditions. In this paper, we have developed a new ranking function to solve a Fully Fuzzy Linear Fractional Programming (FFLFP). The ranking function is derived by replacing the non-parallel sides of the trapezoidal fuzzy number with non-linear functions. Various numerical examples are included and compared with the pre-existing methods.
Javad Pourqasem
Abstract
Internet of Things (IoT) technology is based on interconnected things in a dynamic and distributed environment. The IoT contains many widely pervasive and heterogeneous small things with limited storage, energy resources, and processing capacities. These limitations are an obstacle for developing IoT ...
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Internet of Things (IoT) technology is based on interconnected things in a dynamic and distributed environment. The IoT contains many widely pervasive and heterogeneous small things with limited storage, energy resources, and processing capacities. These limitations are an obstacle for developing IoT applications and involve challenging issues such as interoperability, scalability, performance, and availability. Cloud Computing is one of the promising approaches that can be integrated with IoT to overcome these limitations. The Cloud provides shared resources (network, storage, computing, and software) and is characterized by ubiquitous, low-cost, and virtualization features. This paper presents the Cloud-based IoT platform and describes the communication, processing, and storage properties of it. This platform can benefit from the resources and services of the Cloud to collect, transmit, analyze, process, and store the data generated by the heterogeneous things. We also represent the projects that have implemented the Cloud-based IoT platform.
Other
Sh. Sajana; D. Bharathi
Abstract
This paper deals with the number theoretic properties of non-unit elements of the ring Zn. Let D be the set of all non-trivial divisors of a positive integer n. Let D1 and D2 be the subsets of D having the least common multiple which are incongruent to zero modulo n with every other element of D ...
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This paper deals with the number theoretic properties of non-unit elements of the ring Zn. Let D be the set of all non-trivial divisors of a positive integer n. Let D1 and D2 be the subsets of D having the least common multiple which are incongruent to zero modulo n with every other element of D and congruent to zero modulo n with at least one another element of D, respectively. Then D can be written as the disjoint union of D1 and D2 in Zn. We explore the results on these sets based on all the characterizations of n. We obtain a formula for enumerating the cardinality of the set of all non-unit elements in Zn whose principal ideals are equal. Further, we present an algorithm for enumerating these sets of all non-unit elements.
Machine Learning
F. Furtado; A. Singh
Abstract
Nowadays, the recommendation system has made finding the things easy that we need. Movie recommendation systems aim at helping movie enthusiasts by suggesting what movie to watch without having to go through the long process of choosing from a large set of movies which go up to thousands and millions ...
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Nowadays, the recommendation system has made finding the things easy that we need. Movie recommendation systems aim at helping movie enthusiasts by suggesting what movie to watch without having to go through the long process of choosing from a large set of movies which go up to thousands and millions that is time consuming and confusing. In this article, our aim is to reduce the human effort by suggesting movies based on the user’s interests. To handle such problems, we introduced a model combining both content-based and collaborative approach. It will give progressively explicit outcomes compared to different systems that are based on content-based approach. Content-based recommendation systems are constrained to people, these systems don’t prescribe things out of the box, thus limiting your choice to explore more. Hence, we have focused on a system that resolves these issues.
Econometric Models
S.F. Fakhrehosseini; Meysam kaviani
Abstract
This paper attempts to solve a benchmark money in utility model by first order Taylor approximation to the policy function. After a brief summary of recent development in first order Taylor approximation in solving dynamic stochastic general equilibrium models, we choose Sidrauski’s Money in utility ...
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This paper attempts to solve a benchmark money in utility model by first order Taylor approximation to the policy function. After a brief summary of recent development in first order Taylor approximation in solving dynamic stochastic general equilibrium models, we choose Sidrauski’s Money in utility model as a standard model and follow the approach proposed by Uhlig [1] to solve for the recursive law of motion at first order.
Manufacturing and Logistics
A. Sharma; A. K. Sinha
Abstract
Ultrasonic testing uses high frequency sound waves of a range between 0.5 to 15 MHz to conduct testing. The basic principle and applications of ultrasonic testing techniques is enormous use under the domain of mechanical engineering applications. Importance of ultrasonic testing of rails, train wheels, ...
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Ultrasonic testing uses high frequency sound waves of a range between 0.5 to 15 MHz to conduct testing. The basic principle and applications of ultrasonic testing techniques is enormous use under the domain of mechanical engineering applications. Importance of ultrasonic testing of rails, train wheels, carbon fiber reinforced plastic, aeronautical defects in composite structures, testing of welds, and some other applications are increasing day by day. Literature survey reveals that it is a challenging task for practitioners and researchers to increase the efficiency of non-destructive testing techniques for identifying and localization defects in different mechanical engineering components/parts. Basic fundamentals applications of ultrasonic testing of metal, non-metal, ceramics, polymers, concrete, etc. are briefly explained. Present and future perspective of ultrasonic testing for mechanical engineering domain are discussed along with the sub new development in the area of ultrasonic testing.
Total quality management and quality engineering
E. Nassef; A. Mahmoud; H. Salah; Y. El-taweel
Abstract
The present study aims to removal of copper ions (Cu2+) as a heavy metal ion from aqueous solution by a high inorganic molecular weight compound. This compound is modified clay (activated bentonite) which is used in oil well drilling, and obtained from local company. The experimental results showed that ...
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The present study aims to removal of copper ions (Cu2+) as a heavy metal ion from aqueous solution by a high inorganic molecular weight compound. This compound is modified clay (activated bentonite) which is used in oil well drilling, and obtained from local company. The experimental results showed that it is an adsorption reaction that follows Langmuir isotherm model. The maximum removal of copper ions was obtained at low copper ion initial concentration, high adsorbent dosage, low temperature, and high agitation speed. It is clear from the results obtained that the compound within the experimental range investigated cannot be considered as a method for the removal of waste stream within the experimental range investigated as the residual concentration is higher than the limits which are allowed by the environmental limits which are allowed by the low which is 5 ppm. These results may be due to the high initial copper concentration used in this work and low dosage of the compound.
Kh. Ghaziyani; B. Ejlaly; S. F. Bagheri
Abstract
Data Envelopment Analysis (DEA) is a nonparametric technique used to determine the relative efficiency of Decision Making Units (DMUs). Results from DEA analysis yield important information regarding the optimal operating capabilities of each unit. This paper studies DEA to hospital sectors and identifies ...
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Data Envelopment Analysis (DEA) is a nonparametric technique used to determine the relative efficiency of Decision Making Units (DMUs). Results from DEA analysis yield important information regarding the optimal operating capabilities of each unit. This paper studies DEA to hospital sectors and identifies their rankings during a period of six years. Data for the study comes from a hospital in the North of Iran. This article compares the performance of different parts of the hospital over the years. It can also aid improve hospital performance.