Ultrafine polypropylene (PP) fibers as oil sorbents were fabricated via a needleless melt‐electrospinning device and were characterized by scanning electron microscopy and contact‐angle analysis. PP fibers of various diameters and porosities were obtained by the manipulation of the applied electrical field. The effects of the fiber diameter and porosity on the oil‐sorption capacity and oil‐retention behavior were investigated. The experimental results demonstrate that for fiber diameter on the microscale, the porosity played a paramount role in determining the oil‐sorption capacities. The maximum oil‐sorption capacity of the resulting PP fibers with regard to motor oil and peanut oil were 129 and 80 g/g, respectively; these values were approximately six to seven times that of commercial PP nonwoven fabricated through the melt‐blown method. In addition, even after seven sorption/desorption cycles, the oil‐sorption …

This paper demonstrates a new approach in solving problems with capacity issues within a cement factory in Libya using the Witness simulation package that enables the development of discrete and continuous simulation model to simulate these processes. The model aims to support the implementation of management systems in Supply Chain Management and the introduction of Just-In-Time systems. In order to carry out the above, research has been carried out into processes of SCM and J.I.T. The developed Simulation model is based on Libyan Cement industry, exploring supply chain management (SCM) and Just IN Time (JIT) system from start to end of the processes. Therefore, the aim and objective of investigating supply chain management and applying JIT to the cement factory using simulation at the very stage has been successful and has exercised with the simulation scenarios 1,2 and 3. This was achievable simply based on many assumptions as addressed above and with the help of the witness software that executes duties with the aid of input and output rules that need to be applied accordingly.

Toyota, in Japan started the creation of this method in the early 1960's and hence it is also known as the “Toyota Production System” as it was used for their production of their automobiles. Therefore, the best definition of this system comes from Toyota i.e. JIT is a disciplined programme for improving overall productivity and reducing waste. It provides for the cost-effective production and delivery of only the necessary required parts, in the right quantity, at the right time and place, while using a minimum amount of facilities, equipment, materials and human resources. JIT is dependent upon the balance between the supplier's flexibility and user's stability. It is accomplished through the application of specific techniques that require total employee involvement and teamwork.

ABSTRACT

The research was conducted to investigate the importance of teaching Libyan employees business English and to show the problems that face Libyan employees in using English language skills or business skills and all of that in order to verify the hypothesis which said that the employees in L.F.I.C in Gharian have communicating problems with clients who speak native English because what they have learnt was not enough to apply in real life. A literature review to the nature of teaching business English has illuminate different perspectives on the subject which helped to set out the background of this investigation. In order to investigate this problem data were collected by using questionnaire and test technique that involves the employees of the L.F.I.C. Results and findings indicated that the employees need help to learn more about business English skills. Also, it has been found that the employees had depended on their experience to answer the test. In addition, they can only improve their business English if teachers use the suitable methods and manipulate appropriate teaching techniques to be able to succeed in their company. Although this study has elaborated on various issues regarding teaching business English for Libyan employees, indeed further research is needed in future to understand the nature of teaching business English, hence the employees’ competence can be improved effectively and efficiently.           

Abstract: For electrical drives good dynamic performance is mandatory so as to respond to the changes in command speed and torques, so various speed control techniques are being used for real time applications. The speed of a DC motor can be controlled using various controllers like PID Controller, Fuzzy Logic Controller, Particle Swarm Optimization (PSO) and Hybrid Fuzzy-PSO Controller. Fuzzy-PSO Controller is recently getting increasing emphasis in process control applications. The paper describes application of Hybrid Fuzzy-PSO Controller in an enhancement of stability and accuracy of the SEDC Motor under the effect of the external disturbances and noise that uses the Fuzzy-PSO Controller for enhancement of stability and accuracy of the SEDC Motor under the effect of the external disturbances and noise is implemented in MATLAB/SIMULINK.  The simulation study indicates the superiority Hybrid FuzzyPSO Controller over the Particle Swarm Optimization (PSO) and fuzzy logic controller separately. This control seems to have a lot of promise in the applications of power electronics. The speed of the SEDC motor can be adjusted to a great extent so as to provide easy control and high performance. There are several conventional and numeric types of controllers intended for controlling the SEDC motor speed and executing various tasks: PID Controller, Fuzzy Logic Controller; or the combination between them: FuzzySwarm, Fuzzy-Neural Networks, Fuzzy-Genetic Algorithm, Fuzzy-Ants Colony, Fuzzy-Particle Swarm Optimization. We describe in this paper the use of Hybrid Fuzzy-PSO Controller for enhancement of stability and accuracy of the SEDC Motor under the effect of the external disturbances and noise We describe in this paper the use of Particle Swarm Optimization (PSO) for designing an optimal fuzzy logic controller of a SEDC Motor. In this case, our approach will optimize the membership functions of a fuzzy logic controller (FLC) using PSO and the obtained results were simulated on Matlab environment.

Keywords: Separately Excited DC Motor (SEDC), Fuzzy Logic Controller (FLC), Particle Swarm Optimization(PSO).

This paper considers a common problem that all industries contest with in practice ie the breaking down of machines that influence production and cost directly. In a majority of industrial applications, acquiring optimum utilisation of all available resources for existing and future predicted demand is a major function throughout all the levels of management. This paper uses a number of analytical tools and software that support one another ie Witness Simulation, Bayesian Network Modelling and Hugin Software. The use of expert experience and knowledge has been incorporated throughout the study as it is vital to model building and greater understanding of machine breakdown. This study uses discrete event simulation and Bayesian network modelling collectively to understand machine breakdowns to increase efficiency within a cement manufacturing plant ie the Crusher Machine. The Bayesian network modelling implemented by the Hugin Software is used to generate probabilities which are transferred into a discrete event simulation model using Witness Software based on the historical data, expert knowledge and opinions. The model simulates the three parameters of the machine life based on consumption of each parameter. This is translated into a probability failure rate that changes as the model is running. The model demonstrates decisions based on the probability of failure from the Bayesian model and based on life consumption of the different variables in the simulation model.

Abstract

ABSTRACT: This paper surveyed some of the works on fibre reinforced concrete (FRC) in concrete pavements using recycled waste plastics fibres (WPF) and waste synthetic fibres (WSF) which include its specifications, types, features, benefits and physical properties. Fibres in reinforced concrete pavements can improve their toughness, shrinkage and durability. The use of recycled waste plastic fibres from industrial or post-consumer waste in concrete pavement mixes offers additional advantages as well as for plastics waste reduction, lowers construction cost and resources conservation. Keywords: Fibre Reinforced Concrete, Concrete Pavements, Waste Plastics Fibre, Recycled Waste Plastic

This paper looks into how simulation can be used and developed to combat and aid integrated maintenance and cost optimisation of Libyan cement factory by using simulation as an intelligent maintenance tool to enable intelligent decisions to be made by maintenance management. The cost of preventive maintenance against corrective maintenance, the loss of production and the delay in schedule. Also this paper presents a methodology by integrating maintenance, repair and replacement decisions in bridge management based on reliability, optimization, and life-cycle cost. The overall total cost incurred per minute due to machine failure for more intelligent maintenance decision making. The end result of the model identifies a true to life cost of preventive and corrective maintenance incurred by organisation due to failures.

This paper presents a new approach using Witness Simulation in combating issues related to maintenance within the existing manufacturing facility. Currently, maintenance is a key issue as many machines breakdown due to every day wear and tear as well as the age of the machine itself. This causes bottlenecks within the entire production system as the schedules of production is disturbed and further backlogs are developed. Also, when machines breakdown there seems to be very little communication from one end to another ie parts are needed for the repair of many of the machines, for example, it is very common for the rotary kiln to come to a halt due to increased temperature and different quantities of a mixture of materials. In order to fix the problem and move back on schedule the maintenance team uses certain materials ie same materials, all the time. However, due to not having an adequate stock control system and the lack of communication many a times, parts are not readily available and hence the team wait further until parts arrive at the facility. This paper will demonstrate how all of the above problem areas can be adhered to via the use of adopting a simple automated response system using Witness Simulation. The demonstration will be based on a single machine for testing purposes to ensure efficiency that can later be applied to the entire system as a whole.

This paper explores the use of Bayesian network modeling of machine breakdowns within a cement manufacturing plant. The Bayesian network modeling is introduced using Hugin software and then implemented into a Witness Simulation model using historical data, expert knowledge and opinions. The models simulate 3 parameters of the machine based on life consumption and usage of each parameter, the developed Witness model produces a probability failure rate based on these parameter usages. The failure probability developed by Witness is implemented using the Chain Rule; this is compared with the probability for failure based on the Bayesian network model. This enables the user to see the probability of failure developed by the implementation of the chain rule and Witness based on the parameter usage, on a live streaming fashion as the model is running. This can be used as a decision making tool for management to consider machine maintenance affectively based on parameter usage.