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Showing papers by "Universiti Teknologi Malaysia published in 2010"


Journal ArticleDOI
TL;DR: In this paper, the performance studies of mixed matrix membrane (MMM) for gas separation were critically reviewed, and the materials selection and the preparation techniques of MMM were also discussed.

735 citations


Proceedings ArticleDOI
01 Dec 2010
TL;DR: A new hybrid population-based algorithm (PSOGSA) is proposed with the combination of Particle Swarm Optimization and Gravitational Search Algorithm to synthesize both algorithms' strength.
Abstract: In this paper, a new hybrid population-based algorithm (PSOGSA) is proposed with the combination of Particle Swarm Optimization (PSO) and Gravitational Search Algorithm (GSA) The main idea is to integrate the ability of exploitation in PSO with the ability of exploration in GSA to synthesize both algorithms' strength Some benchmark test functions are used to compare the hybrid algorithm with both the standard PSO and GSA algorithms in evolving best solution The results show the hybrid algorithm possesses a better capability to escape from local optimums with faster convergence than the standard PSO and GSA

535 citations


Journal ArticleDOI
01 Aug 2010-Energy
TL;DR: In this paper, the potential use of hybrid photovoltaic (PV)/diesel energy system in remote locations was analyzed and the suitability of utilizing hybrid PV and diesel energy system over standalone diesel system was discussed mainly based on different solar irradiances and diesel prices.

339 citations


Journal ArticleDOI
TL;DR: The model for surface roughness in the milling process could be improved by modifying the number of layers and nodes in the hidden layers of the ANN network structure, particularly for predicting the value of the surface Roughness performance measure.
Abstract: This paper presents the ANN model for predicting the surface roughness performance measure in the machining process by considering the Artificial Neural Network (ANN) as the essential technique for measuring surface roughness. A revision of several previous studies associated with the modelling issue is carried out to assess how capable ANN is as a technique to model the problem. Based on the studies conducted by previous researchers, the abilities and limitations of the ANN technique for predicting surface roughness are highlighted. Utilization of ANN-based modelling is also discussed to show the required basic elements for predicting surface roughness in the milling process. In order to investigate how capable the ANN technique is at estimating the prediction value for surface roughness, a real machining experiment is referred to in this study. In the experiment, 24 samples of data concerned with the milling operation are collected based on eight samples of data of a two-level DOE 2^k full factorial analysis, four samples of centre data, and 12 samples of axial data. All data samples are tested in real machining by using uncoated, TiAIN coated and SN"T"R coated cutting tools of titanium alloy (Ti-6A1-4V). The Matlab ANN toolbox is used for the modelling purpose with some justifications. Feedforward backpropagation is selected as the algorithm with traingdx, learngdx, MSE, logsig as the training, learning, performance and transfer functions, respectively. With three nodes in the input layer and one node in the output layer, eight networks are developed by using different numbers of nodes in the hidden layer which are 3-1-1, 3-3-1, 3-6-1, 3-7-1, 3-1-1-1, 3-3-3-1, 3-6-6-1 and 3-7-7-1 structures. It was found that the 3-1-1 network structure of the SN"T"R coated cutting tool gave the best ANN model in predicting the surface roughness value. This study concludes that the model for surface roughness in the milling process could be improved by modifying the number of layers and nodes in the hidden layers of the ANN network structure, particularly for predicting the value of the surface roughness performance measure. As a result of the prediction, the recommended combination of cutting conditions to obtain the best surface roughness value is a high speed with a low feed rate and radial rake angle.

313 citations


Journal ArticleDOI
TL;DR: The results indicate that LVM adsorbs MO efficiently and could be utilized as a low-cost alternative adsorbent for the removal of anionic dyes in wastewater treatment.

231 citations


Journal ArticleDOI
TL;DR: The analysis of this study has proven that the GA technique is capable of estimating the optimal cutting conditions that yield the minimum surface roughness value.
Abstract: This study is carried out to observe the optimal effect of the radial rake angle of the tool, combined with speed and feed rate cutting conditions in influencing the surface roughness result. In machining, the surface roughness value is targeted as low as possible and is given by the value of the optimal cutting conditions. By looking at previous studies, as far as they have been reviewed, it seems that the application of GA optimization techniques for optimizing the cutting conditions value of the radial rake angle for minimizing surface roughness in the end milling of titanium alloy is still not given consideration by researchers. Therefore, having dealt with radial rake angle machining parameter, this study attempts the application of GA to find the optimal solution of the cutting conditions for giving the minimum value of surface roughness. By referring to the real machining case study, the regression model is developed. The best regression model is determined to formulate the fitness function of the GA. The analysis of this study has proven that the GA technique is capable of estimating the optimal cutting conditions that yield the minimum surface roughness value. With the highest speed, lowest feed rate and highest radial rake angle of the cutting conditions scale, the GA technique recommends [email protected] as the best minimum predicted surface roughness value. This means the GA technique has decreased the minimum surface roughness value of the experimental sample data, regression modelling and response surface methodology technique by about 27%, 26% and 50%, respectively.

198 citations


Journal ArticleDOI
TL;DR: In this paper, the effects of linear low density polyethylene (LLDPE) and organophilic modified montmorillonite (MMT) on mechanical, thermal and morphological properties of PLA were investigated.

178 citations


Journal ArticleDOI
TL;DR: It is suggested that the anti-cancer activity of bromelain consists in the direct impact on cancer cells and their micro-environment, as well as in the modulation of immune, inflammatory and haemostatic systems.

176 citations


Journal ArticleDOI
TL;DR: It is proposed that the formation of cyclized structure by oxidation treatment minimized the nitrogen loss during steam activation, hence increased the uptake performance of activated carbons.

175 citations


Journal ArticleDOI
TL;DR: In this paper, the fracture behaviour of short bamboo fiber reinforced polyester composites is investigated and the results reveal that at 4mm of fibre length, the increment in fibre content deteriorates the fracture toughness.

171 citations


Journal ArticleDOI
TL;DR: In this paper, the authors report the work on oil palm empty fruit bunch (OPEFB) fiber-reinforced polymer composites with some interest on the OPEFB physical structure, and chemical compositions.
Abstract: Natural fiber-reinforced polymer composite materials have emerged in a wide spectrum of area of the polymer science. The composite produced from these types of materials are low density, low cost, comparable specific properties, and most importantly they are environmental friendly. The composite materials produced from oil palm fibers and commercially available polymers have offered some specific properties that can be comparable to conventional synthetic fiber composite materials. However, these properties are greatly dependent on the compatibility of oil palm fibers and matrix phase with moisture absorption as one of the critical issues that becomes the drawbacks of the oil palm fiber polymer composite materials. Apparently, it greatly affects the physical as well as mechanical properties of the composite materials. The present review reports the work on oil palm empty fruit bunch (OPEFB) fiber-reinforced polymer composites with some interest on the OPEFB physical structure, and chemical compositions. Finally, the incorporation of OPEFB into polymeric materials leads to several interesting consequences on the water absorption characteristics and the mechanical properties, which have been reviewed.

Journal ArticleDOI
TL;DR: In this article, the effects of non-solvent additives, polymeric additives, polymer concentration and volatile solvent on the performance and morphology of polysulfone flat sheet gas separation membranes have been investigated.

Journal ArticleDOI
TL;DR: In this article, the energy absorption of conical conical tubes under oblique impact loading was quantified for variations in the load angle and geometry parameters of the tube, and it was shown that foam-filled conical tube are preferable as impact energy absorbers due to their ability to withstand oblique impacts as effectively as axial impact loads.

Journal ArticleDOI
TL;DR: In this article, the authors have reviewed the literature on TQM and organized the paper along two main themes: the evolution of TQMs considered as a set of practices, and its impacts on organisational performance.
Abstract: Total quality management (TQM) has been considered as an infrastructural strategy in the operations management research field. It is one of the most recognised models for operational excellence besides lean operation, supply chain management, and technology management. Both manufacturing and service organisations tend to implement this strategy in order to maintain their competitive advantage. The purpose of this paper is to develop the conceptual model of TQM implementation in relation to organisational performance. The authors have reviewed the literature on TQM and organised the paper along two main themes: the evolution of TQM considered as a set of practices, and its impacts on organisational performance. Two research questions are proposed in order to re-validate TQM constructs: (1) Is the set of practices associated with TQM valid as a whole? (2) What performance measures should be considered to exhibit the effectiveness of its implementation?

Journal ArticleDOI
TL;DR: In this paper, the effect of alkalis (NaOH, KOH and K 2 CO 3 ) on liquefaction of EPFB (empty palm fruit bunch) biomass liquidefaction was investigated under subcritical water conditions in a batch reactor operating at 270°C and 20 bars for a period of 20min.

Journal ArticleDOI
TL;DR: In this article, the effect of different operating parameters such as absorbent temperature, CO2 pressure, absorbent flow rate and long-term operation on the CO2 flux of the hollow fiber membrane was investigated.

Proceedings ArticleDOI
01 Dec 2010
TL;DR: A MATLAB Simulink simulator for photovoltaic (PV) system using the two-diode model to represent the PV cell which is known to have better accuracy at low irradiance level which allows for a more accurate prediction of PV system performance.
Abstract: This paper proposes a MATLAB Simulink simulator for photovoltaic (PV) system. The main contribution of this work is the utilization of the two-diode model to represent the PV cell. This model is known to have better accuracy at low irradiance level which allows for a more accurate prediction of PV system performance. To reduce computational time, the input parameters are reduced to four and the values of Rp and Rs are estimated by an efficient iteration method. Furthermore, all the inputs to the simulator are information available on standard PV module datasheet. The simulator supports large array simulation that can be interfaced with MPPT algorithms and power electronic converters. The accurateness of the simulator is verified by applying the model to two PV modules. It is envisaged that the proposed work can be very useful for PV professionals who require simple, fast and accurate PV simulator to design their systems.

Journal ArticleDOI
TL;DR: This paper proposes an Ant System (AS) (one of the ACO variants) to solve Unequal Area Facility Layout Problems (UA-FLPs), and uses slicing tree representation to easily represent the problems without too restricting the solution space.

Journal ArticleDOI
TL;DR: Granular sludge could be developed in a single reactor with an intermittent anaerobic-aerobic reaction phase and is capable in treating the textile wastewater and demonstrated good removal of COD and ammonia.

Journal ArticleDOI
TL;DR: It can be concluded that the low cost and economical rice husk ash-synthesized zeolite NaY could be a better sorbent for ammonium removal due to its rapid adsorption rate and higher adsorptive capacity compared to natural mordenite.

Journal ArticleDOI
TL;DR: In this article, the authors reported experimental measurements of the streaming potential coupling coefficient in sandstones saturated with NaCl-dominated artificial and natural brines up to 5.5 M (321.4 g L−1 of NaCl; electrical conductivity of 23 S m−1).
Abstract: We report experimental measurements of the streaming potential coupling coefficient in sandstones saturated with NaCl-dominated artificial and natural brines up to 5.5 M (321.4 g L−1 of NaCl; electrical conductivity of 23 S m−1). We find that the magnitude of the coupling coefficient decreases with increasing brine salinity, as observed in previous experimental studies and predicted by models of the electrical double layer. However, the magnitude of the coupling coefficient remains greater than zero up to the saturated brine salinity. The magnitude of the zeta potential we interpret from our measurements also decreases with increasing brine salinity in the low-salinity domain ( 0.4 M). We hypothesize that the constant value of zeta potential observed at high salinity reflects the maximum packing of counterions in the diffuse part of the electrical double layer. Our hypothesis predicts that the zeta potential becomes independent of brine salinity when the diffuse layer thickness is similar to the diameter of the hydrated counterion. This prediction is confirmed by our experimental data and also by published measurements on alumina in KCl brine. At high salinity (>0.4 M), values of the streaming potential coupling coefficient and the corresponding zeta potential are the same within experimental error regardless of sample mineralogy and texture and the composition of the brine.

Journal ArticleDOI
TL;DR: An Inherent Occupational Health Index has been developed for assessing the health risks of process routes during process research and development stage and it is demonstrated by comparing the inherent occupational healthiness of six methyl methacrylate process routes using three different types of index calculations.
Abstract: Occupational health studies the interaction of work and health, especially the long-term effect of chemicals to health. In this paper an Inherent Occupational Health Index has been developed for assessing the health risks of process routes during process research and development stage. The method takes into account both the hazard from the chemicals present and the potential for the exposure of workers to the chemicals. The index can be used either for determining the level of inherent occupational health hazards or comparing alternative process routes for these risks. The method is tailored for the process research and development stage by including only such properties of chemicals and operating conditions of process, which are available already in this early stage. In the end of this paper the approach is demonstrated by comparing the inherent occupational healthiness of six methyl methacrylate process routes using three different types of index calculations; additive-type, average-type, and worst case-type. The study discloses that the average- and worst case-based approaches analyze the characteristics of a route better than the additive calculation, which is greatly affected by the number of steps in the route. A quantitative standard scale for the index is also developed to allow health level assessment of a single process.

Journal ArticleDOI
TL;DR: In this paper, the effect of chitosan as a functionalization agent on the performance and separation properties of polyimide/multi-walled carbon nanotubes mixed matrix flat sheet membranes were investigated.

Journal ArticleDOI
TL;DR: In this article, a Mixed Integer Linear Programming (MILP) model was developed for the optimal planning of electricity generation schemes for a nation to meet a specified CO2 emission target.

Journal ArticleDOI
TL;DR: In this paper, the effects of polyvinylpyrrolidone (PVP) and 2, 4, 6-triaminopyrimidine (TAP) on the surface properties of the silver-filled asymmetric membrane were investigated for antibacterial application.

Proceedings ArticleDOI
01 Oct 2010
TL;DR: In this article, the authors proposed a Maximum Power Point Tracking (MPPT) algorithm based on Differential Evolution (DE) that is capable of tracking global MPP under partial shaded conditions.
Abstract: Photovoltaic (PV) system performance extremely depends on local insolation and temperature conditions. Under partial shading, P-I characteristics of PV systems are complicated and may have multiple local maxima. Conventional Maximum Power Point Tracking (MPPT) techniques can easily fail to track global maxima and may be trapped in local maxima under partial shading; this can be one of main causes for reduced energy yield for many PV systems. In order to solve this problem, this paper proposes a novel Maximum Power Point tracking algorithm based on Differential Evolution (DE) that is capable of tracking global MPP under partial shaded conditions. The ability of proposed algorithm and its excellent performances are evaluated with conventional and popular algorithm by means of simulation. The proposed algorithm works in conjunction with a Boost (step up) DC-DC converter to track the global peak. Moreover, this paper includes a MATLAB-based modeling and simulation scheme suitable for photovoltaic characteristics under partial shading.

Journal ArticleDOI
TL;DR: In this paper, a phase-inversion method was used to fabricate polysulfone (PSf) hollow fiber membranes by using low molecular weight additives in the spinning dopes.

Journal ArticleDOI
TL;DR: In this paper, the effect of lithium chloride (LiCl) concentration as non-solvent additive in the spinning dopes on the structure and CO 2 absorption performance of the polyvinylidene fluoride (PVDF) membranes was investigated.

Journal ArticleDOI
TL;DR: The new developed SPMTE method showed comparable or even better results against reference method and is a simple, feasible, and cost effective microextraction technique.

Journal ArticleDOI
TL;DR: In this article, polyetherimide (PEI) hollow fiber membranes were used in gas-liquid contacting process and the mean pore size, effective surface porosity and void fraction of membranes decreased as the polymer concentration increased, while LEPw and membrane density increased.