El-hefian E.A.,University of Malaya |
Nasef M.M.,UniversitiTeknologi Malaysia |
Yahaya A.H.,University of Malaya
Australian Journal of Basic and Applied Sciences | Year: 2011
Chitosan is a modified carbohydrate polymer derived industrially by hydrolyzing the aminoacetyl groups of chitin. It is a natural, biodegradable, biocompatible, non-toxic, and anti-bacterial poly-saccharide available in different forms such as solution, powder, flake, fiber and film. Due to its wide range of physical forms, chitosan has broad applications in different fields. This paper reviews the latest development in the physical forms of chitosan and its blends. Various physical forms of chitosan and its blends together with other derivatives such as composites and graft copolymers have been developed to overcome its disadvantages such as poor mechanical properties and to improve its functionality towards specific applications. The progress made in converting chitosan and its blends into various physical forms as well as the preparation methods are presented.
Noah N.N.F.M.,UniversitiTeknologi Malaysia |
Othman N.N.,UniversitiTeknologi Malaysia
Chemical Engineering Transactions | Year: 2017
Emulsion Liquid Membrane (ELM) process is one of the alternative techniques to extract solutes from wastewater. It has been given considerable attention due to its advantages such as simultaneous extraction and recovery in a single step operation, non-equilibrium mass transfer, high fluxes, low energy consumption, reusability and high selectivity. The main concern in order to achieve high stability in the process is the size of internal droplets of primary emulsion. This study aims to investigate the affecting parameters such as concentration of surfactant, emulsification speed and emulsification time. ELM process containing bis(2,4,4-Trimethylpentyl) monothiophosphinic acid (Cyanex 302) as a mobile carrier in kerosene and acidic thiourea as stripping agent was used. The stability results showed that 2.8 μm of droplet diameter was formed at favorable condition of 2 % w/v surfactant concentration, 12,000 rpm of emulsification within 3 min of emulsification time. At this condition, 84 % of Palladium was extracted. Copyright © 2017, AIDIC Servizi S.r.l..
Hebbar R.S.,National Institute of Technology Karnataka |
Isloor A.M.,National Institute of Technology Karnataka |
Ismail A.F.,UniversitiTeknologi Malaysia
RSC Advances | Year: 2014
Nanofiltration (NF) membranes are continually sought for their unique physical and chemical properties, which allow filtration of electrolytes, dyes and other substances. In continuation of our efforts to prepare NF membranes, flat sheet polyetherimide/hydrolysed poly(isobutylene-alt-maleic anhydride) (PIAM) blend membranes have been prepared. The main aim was to explore the effect of addition of PIAM on morphological features and permeation properties of the membranes. The presence of dicarboxlic acid functionality leads to an enhancement in the hydrophilicity and antifouling properties. The results revealed that increasing the content of hydrolysed PIAMdecreases the pore size of the membranes and subsequently increases the electrolyte rejection. The PEI/hydrolysed PIAM composition (80 : 20) showed reasonably good salt rejection (sodium sulphate of 1000 ppm) of up to 76% with a pure water flux of 11.8 L m-2 h-1 at 0.4 MPa transmembrane pressure. This study provides a simple and effective approach to produce a negatively charged NF membranes for water desalination applications with low energy consumption. © The Royal Society of Chemistry 2014.
Vanaki S.M.,University of Malaya |
Ganesan P.,University of Malaya |
Mohammed H.A.,UniversitiTeknologi Malaysia
Renewable and Sustainable Energy Reviews | Year: 2016
The recent development of nanotechnology led to the concept of using suspended nanoparticles in heat transfer fluids to improve the heat transfer coefficient of the base fluids. Specifically, numerical studies are reviewed in this study to get a clear view and detailed summary of the influence of several parameters such as type of nanoparticle and host liquid, particle volume concentration, particle size, particle shape, Brownian diffusion and thermophoresis effect on hydrodynamic and thermal characteristics of convective heat transfer using nanofluids. In addition, the paper provides detailed information about the most of commonly-used correlations which are utilized to predict the effective thermophysical properties of nanofluids. Finally, the main aim upon which the present work is based is to give a comprehensive review on different CFD approaches employed in numerical simulation of nanofluid flow, address the pros and cons of each approach, and find the suitable technique which gives more credible results as compared to experimental results. © 2015 Published by Elsevier Ltd.
Pohl C.,UniversitiTeknologi Malaysia
IOP Conference Series: Earth and Environmental Science | Year: 2014
With Malaysia being the second largest palm oil producer in the world and the fact that palm oil ranks first in vegetable oil production on the world market the palm oil industry became an important factor in the country. Along with the expansion of palm oil across the nation causing deforestation of natural rain forest and conversion of peat land into plantation land there are several factors causing a tremendous increase in carbon dioxide (CO2) emissions. Main causes of CO2 emission apart from deforestation and peat-land conversion are the fires to create plantation land plus the fires burning waste products of the plantations itself. This paper describes a project that aims at the development of a remote sensing monitoring system to allow a continuous observation of oil palm plantation activities and expansion in order to be able to quantify CO2 emissions. The research concentrates on developing a spaceborne synthetic aperture radar information extraction system for palm oil plantations in the Tropics. This will lead to objective figures that can be used internationally to create a policy implementation plan to sustainably reduce CO2 emission in the future. © Published under licence by IOP Publishing Ltd.
Marghany M.,UniversitiTeknologi Malaysia
International Journal of Physical Sciences | Year: 2011
This paper presents work done to utilize RADARSAT-1 synthetic aperture radar (SAR) data to reconstruct 3-D of coastal water front. The velocity bunching model was used to extract the significant wave height from RADARSAT-1 SAR, while the Volterra model was used to model the front movements. B-spline also was implemented to reconstruct the front into 3-D. This study shows that the integration between velocity bunching, Volterra models and B-spline can be used as geomatica tool for 3-D front reconstruction.
Talebian-Kiakalaieh A.,UniversitiTeknologi Malaysia |
Amin N.A.S.,UniversitiTeknologi Malaysia
Catalysis Today | Year: 2015
The gas phase dehydration of glycerol to acrolein over a series of supported silicotungstic acid (HSiW) on zirconia (10HZ, 20HZ, 30HZ and 40HZ) has been investigated. The catalysts were characterized by temperature programmed desorption, nitrogen adsorption-desorption, thermogravimetric analysis, Fourier transform infrared spectroscopy, X-ray diffraction, field-emission scanning electron microscopy and energy dispersive X-ray techniques. The large pore diameters (>19nm) of the prepared catalysts alleviated the coke deposition effect. Also, the specific surface area and acidity of the samples surged from 18 to 22m2/g and 0.38 to 1.24mmol/gcat, respectively by varying HSiW loadings from 10 to 40wt% on zirconia. The highest acrolein yield achieved was 63.75% at 92% glycerol conversion over 30HZ catalyst for 10wt% glycerol feed concentration and 300°C reaction temperature in 3h. The combined physico-chemical characteristics of 30HZ made it more superior compared with other samples in the current study. © 2015 Elsevier B.V.
Ho W.S.,UniversitiTeknologi Malaysia |
Tohid M.Z.W.M.,UniversitiTeknologi Malaysia |
Hashim H.,UniversitiTeknologi Malaysia |
Muis Z.A.,UniversitiTeknologi Malaysia
International Journal of Electrical Power and Energy Systems | Year: 2014
In a previous work, Electricity System Cascade Analysis (ESCA) was applied to optimize a Distributed Energy Generation (DEG) system consisting of a non-intermittent power generator and an energy storage device. DEG systems consisting of intermittent power source however were not discussed. This work thus extends the application of ESCA for intermittent resources. New ESCA proposed in this work has significance differences in term of execution strategy. The main cause of the differences is due to intermittent power generation which influenced by weather variability. In addition, this work includes the sizing of inverter. In this paper, the new ESCA was applied to optimize a solar PV system for an isolated rural house with daily energy consumption of 5.575 kW h. © 2013 Elsevier Ltd. All rights reserved.
Marghany M.,UniversitiTeknologi Malaysia |
Hashim M.,UniversitiTeknologi Malaysia
International Geoscience and Remote Sensing Symposium (IGARSS) | Year: 2011
In this study, we investigate the relative ability of a Box-Jenkins algorithm to retrieve sea surface salinity (SSS) from MODIS satellite data. The accuracy of this work has been examined using the root mean square of bias of sea surface salinity retrieved from MODIS satellite data. The study shows comprehensive relationship between Box-Jenkins algorithm, least square method, and in situ SSS measurements with high r2 of 0.98, 0.96 and RMS of bias value of ±0.34 psu, and ±0.32 psu, respectively. Thus, lower RMS of bias value of ± 0.32 psu has performed with Box-Jenkins algorithm. In conclusions, Box-Jenkins algorithm can be used to retrieve time series of SSS from MODIS satellite data as compared to least square algorithm. © 2011 IEEE.
Azmi S.A.M.,UniversitiTeknologi Malaysia |
Sahar M.R.,UniversitiTeknologi Malaysia
Materials Science Forum | Year: 2016
Nickel nanoparticles are incorporated in Sm3+ doped zinc phosphate glass having a composition of 40ZnO-(58-x)P2O5-1Sm2O3-xNiO, with x = 0.0 and 2.0 mol% prepared by melt quenching technique. Sample characterizations are made by means of X-ray diffraction, transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). X-ray diffraction shows that the glass is in the amorphous state. The transmission electron microscopic (TEM) image reveals the existence of Nickel nanoparticles having a particles size in the range of 5.5 – 21.8 nm. The magnetization M(H) curve reveals that the glass displays an anomalous hysteresis behavior at room temperature. It is observed that the initial curve of magnetization lies positively as a function of the magnetic field under 1000 H (O.e). © 2016 Trans Tech Publications, Switzerland.