623 research outputs found
Process system engineering in biodiesel production: a review
Biodiesel is fast becoming a popular alternative to fossil fuels, as it is natural, renewable and has low toxic emissions. Strategies that have been adopted to ensure continued growth of the biodiesel industry are policy development, reduction of biodiesel tax, offset funding for incremental fuel cost from CO2 emission fuel and support for research and development of potential biodiesel feedstocks. Recent innovations of biodiesel processes are focused on the development of more efficient catalysts and in the utilization of novel reaction media such as supercritical fluids as well as on a variety of oil feedstocks such as virgin and waste oils. Biodiesel production involves complex processes which require systematic process design and optimization. The main aim of designing biodiesel plants is to maxime conversion of ethyl or methyl esters at the lowest capital cost of the plant. The design should also consider safety and environmental concerns. Process system engineering (PSE) is a systematic approach to design and analyze complex processes by using a variety of PSE tools for the optimization of biodiesel production. This paper reviews the latest PSE tools used in development of novel biodiesel processes. It describes the main PSE elements such as process model development and product design, simulation of biodiesel processes, optimization of biodiesel synthesis, and integration of reactor and separation systems. This review also highlights the sustainability of biodiesel production
Process system engineering in biodiesel production: a review
Biodiesel is fast becoming a popular alternative to fossil fuels, as it is natural, renewable and has low toxic emissions. Strategies that have been adopted to ensure continued growth of the biodiesel industry are policy development, reduction of biodiesel tax, offset funding for incremental fuel cost from CO2 emission fuel and support for research and development of potential biodiesel feedstocks. Recent innovations of biodiesel processes are focused on the development of more efficient catalysts and in the utilization of novel reaction media such as supercritical fluids as well as on a variety of oil feedstocks such as virgin and waste oils. Biodiesel production involves complex processes which require systematic process design and optimization. The main aim of designing biodiesel plants is to maxime conversion of ethyl or methyl esters at the lowest capital cost of the plant. The design should also consider safety and environmental concerns. Process system engineering (PSE) is a systematic approach to design and analyze complex processes by using a variety of PSE tools for the optimization of biodiesel production. This paper reviews the latest PSE tools used in development of novel biodiesel processes. It describes the main PSE elements such as process model development and product design, simulation of biodiesel processes, optimization of biodiesel synthesis, and integration of reactor and separation systems. This review also highlights the sustainability of biodiesel production
Methyl esters selectivity of transesterification reaction with homogenous alkaline catalyst to produce biodiesel in batch, plug flow, and continuous stirred tank reactors
Selectivity concept is essential in establishing the best operating conditions for attaining maximum production of the desired product. For complex reaction such as biodiesel fuel synthesis, kinetic studies of transesterification reaction have revealed the mechanism of the reaction and rate constants. The objectives of this research are to develop the kinetic parameters for determination of methyl esters and glycerol selectivity, evaluate the significance of the reverse reaction in transesterification reaction, and examine the influence of reaction characteristics (reaction temperature, methanol to oil molar ratio, and the amount of catalyst) on selectivity. For this study, published reaction rate constants of transesterification reaction were used to develop mathematical expressions for selectivities. In order to examine the base case and reversible transesterification, two calculation schemes (Case 1 and Case 2) were established. An enhanced selectivity was found in the base case of transesterification reaction. The selectivity was greatly improved at optimum reaction temperature (60 C), molar ratio (9 : 1), catalyst concentration (1.5 wt.%), and low free fatty acid feedstock. Further research might explore the application of selectivity for specifying reactor configurations
Methyl esters selectivity of transesterification reaction with homogenous alkaline catalyst to produce biodiesel in batch, plug flow, and continuous stirred tank reactors
Selectivity concept is essential in establishing the best operating conditions for attaining maximum production of the desired product. For complex reaction such as biodiesel fuel synthesis, kinetic studies of transesterification reaction have revealed the mechanism of the reaction and rate constants. The objectives of this research are to develop the kinetic parameters for determination of methyl esters and glycerol selectivity, evaluate the significance of the reverse reaction in transesterification reaction, and examine the influence of reaction characteristics (reaction temperature, methanol to oil molar ratio, and the amount of catalyst) on selectivity. For this study, published reaction rate constants of transesterification reaction were used to develop mathematical expressions for selectivities. In order to examine the base case and reversible transesterification, two calculation schemes (Case 1 and Case 2) were established. An enhanced selectivity was found in the base case of transesterification reaction. The selectivity was greatly improved at optimum reaction temperature (60 C), molar ratio (9 : 1), catalyst concentration (1.5 wt.%), and low free fatty acid feedstock. Further research might explore the application of selectivity for specifying reactor configurations
Electrical Transport and Related Dielectric Phenomena in Coconut-Shell Activated Carbon
The electrical properties of coconut-shell activated carbon
have not been thoroughly investigated and are, therefore, not
well understood. In order to study these properties
meaningfully, a fairly satisfactory knowledge of the structure,
microstructure and composition of the material is needed.
Since the material's constitution has been little studied
and dealt with in the relevant published literature,
investigation of the structure and composition of the material
has to be done in a comprehensive manner.The experimental
investigation is divided into two categories. Firstly, the basic
experimental work, which is considered important in order to
provide supportive evidence to any proposed model of
charge-carrier conduction and dielectric behaviour, consists of work on x-ray diffractome try, neutron activation analysis,
Fourier transform infra-red spectroscopy, scanning electron
microscopy, thermoelectric power and magnetoresistance.
Secondly,the main experiments consist of work on direct current
conductivity and alternating current conductivity measurement
Surface Electromyography of Eyes Potential Behaviour using Wavelet Transform Analysis
The previous study of eyes potential behavior was carried out using Fourier Transform
which is found to be working on a single scale. Then, Wavelet Transform was proposed to overcome the limitation. Hence, the objective of this paper is to identify the surface electromyography of eye movement potentials behavior by using Wavelet Transform scalogram analysis. The eye movement signals are detected by using electrodes that are placed on a person’s forehead around the eye. It then recorded the signal using the data acquisition Electroencephalograph Neurofax-9200. The eye moved towards various directions involving 15 humans were identified. The Wavelet scalogram analyzed the eye movement signals by comparing the energy distribution with the change of time and frequency of each signal. The results proved that different surface electromyography of eye movement signals created different signals energy with their corresponding scales. Analysis of variance statistically proved that there was a 99% significance difference between each scale indicating that each eye movement has different frequency bands and energy distribution. These findings could be integrated to design a support machine for paralyzed people to move their robot or wheelchair by using eye movements. Future works should explore the energy and frequency bands distribution within four eye movement signals for better interpretation of surface Electromyography signals analysis by using Wavelet scalogram
Kepuasan Pelanggan dan Kualiti Perkhidmatan Skim Ar-Rahnu Bank Rakyat
The purpose of this study is to examine the level of satisfaction among the customer of ar-Rahnu scheme at Bank Rakyat Alor Setar, Kedah towards the service quality provided. The measurement of service quality was modified and adapted from Othman and Owen (2001) and Parasuraman et al. (1991) with 1-5 scale. The instrument consists of six dimensions namely compliance, assurance, reliability, tangible, empathy and responsiveness. Meanwhile, the measurement of customer satisfaction was adapted from Othman and Owen (2001) and McDougall and Lvesque (1994). This study chooses Bank Rakyat at Alor Setar, Kedah and 100 questionnaires were distributed. The systematic convenient sampling technique was used. The data gathered were analysed using Statistical Package for Social Science (SPSS) v.14. The study used descriptive analysis, correlation Pearson, means, t-test, ANOVA and multiple regression tests. The score means showed that the level of satisfaction of customer was high. In correlation Pearson test, it showed that all six dimensions of service quality have significant relationship with customer satisfaction. Beside of that, in t-test showed that in terms of demographic factor, female have strong significant relationship with customer satisfaction. Multiple regression analysis indicates that the service quality explained 45.9% of the variance in the customer satisfaction. The dimension of empathy considered as the critical factor in the customer satisfaction, and the other five dimensions are less emphasized factors. It can be concluded that the customers were satisfied with the service quality provided by Bank Rakyat Alor Setar, Kedah. More attention should be given to the customers by improving dimensions of compliance, assurance, reliability, tangible and responsiveness
An axiological study on Islamic visual art in Malaysia from 1957 to 1999 / Wan Samiati Andriana W. Mohamad Daud
The Islamic values were determined from Allah SWT through the Al-Quran and the guidance of the Prophet Muhammad SAW. The aims of this study were to determine the axiological aspect of the Contemporary Malaysian Islamic Visual Art, to explore the historical events and the development of the Malaysian Islamic Art from the year of 1957 to 1999, and to provide a comprehensive document on the history of the Contemporary Malaysian Islamic Visual Art based on history, tradition and culture of Islam. This research was conducted by using mixed methods of qualitative and quantitative research method. The quantitative research utilized questionnaire to solicit the data . The information gathered through data collection inclusive of three major issues, the concept, the national policies and the events or exhibitions gathered from various sources, including academic books, journal, proceedings as well as exhibition catalogues cum books of painting, retrospectives, biographies, competition booklets and website. The important events on Islamic art were also gathered through the articles presented at seminars and symposiums as well as newspaper cuttings and magazines. The study also analysed ninety five (95) pieces of artworks consist of artwork from painting, printmaking, sculpture and mix media such as collages, assemblages, digital print, fabric works and two-dimensional construction that were exhibited in Islamic Art exhibitions held in Malaysia from the years 1957 to 1999 and were selected from those created by the Muslim artists with the Islamic Art themes only
A modification of fuzzy arithmetic operators for solving near-zero fully fuzzy matrix equation
Matrix equations have its own important in the field of control system engineering particularly in the stability analysis of linear control systems and the reduction of nonlinear control system models. There are certain conditions where the classical matrix equation are not well equipped to handle the uncertainty problems such as during the process of stability analysis and reduction in control system engineering. In this study, an algorithm is developed for solving fully fuzzy matrix equation particularly for ~ A ~X ~B ~X = ~ C, where the coefficients of the equation are in near-zero fuzzy numbers. By modifying the existing fuzzy multiplication arithmetic operators, the proposed algorithm exceeds the positive restriction to allow the near-zero fuzzy numbers as the coefficients. Besides that, a new fuzzy subtraction arithmetic operator has also been proposed as the existing operator failed to satisfy the both sides of the nearzero fully fuzzy matrix equation. Subsequently, Kronecker product and V ec-operator are adapted with the modified fuzzy arithmetic operator in order to transform the fully fuzzy matrix equation to a fully fuzzy linear system. On top of that, a new associated linear system is developed to obtain the final solution. A numerical example and the verification of the solution are presented to demonstrate the proposed algorithm
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