Synthesis of palm oil based-urethane acrylate (POBUA) resins was carried out by acrylation of epoxidizedpalm oil (EPOP) using acrylic acid in the presence of a catalyst and followed by isocyanation to obtainthe POBUA. Using the monomer as a diluent in the formulation, 4% of photoinitiator and incorporationof organoclay (1-5% wt), nanocomposites were obtained upon UV irradiation. The X-ray DiffractoryXRD study revealed that the nanocomposites obtained were of the exfoliation type. The presence ofthe clay improved the hardness and did not affect the thermal stability. Similarly, it increased the glasstransition temperature Tg but reduced the modulus as the clay content was increased. The improvementof the tensile strength was only obtained when the clay concentration was 5 phr.
This paper reviewed the aspect of fatigue approaches and analysis in a fibre reinforced composite materials which have been done by researchers worldwide. The aim of this review is to provide a better picture on analytical approaches that are presently available for predicting fatigue life in composite materials. This review also proposes a new interpretation of available theories and identifies area in fatigue of natural fibre reinforced composite materials. Thus, it was concluded there are still very limited studies on fatigue analysis of natural fibre reinforced composite materials, especially using non-destructive technique (NDT) methods and a new mathematical modelling on fatigue should be formulated.
Elderly are exposed to physical impairment. This has a strong impact on their daily activities including
frying, which is one of the most popular cuisine preparations. The stove height and work envelope
are two major ergonomic issues in performing cooking task. There has been little research focusing
on Malaysian elderly task performing in addressing these issues. The objectives of this study were to
identify the acceptable stove height and depth and to determine the working envelope among Malaysian
elderly using anthropometric data. A total of 55 Malaysian elderly (25 male and 30 female) aged between
60 to 85 years participated in this study. Five body measurements were taken from each subject using
an anthropometer. The measurements are stature height, shoulder height, arm span, arm reach forward
and waist height. Apart from these anthropometric measurements, their present stove height was also
measured. The acquisition of stove height dimensions was performed through a series of door to door
visit of the elderly homes in Kg. Sg. Merab. These variables were used to estimate the elderly working
envelope and determine the stove height, width and depth. Data were analysed using SPSS software. The
waist height dimension was to estimate the stove height, the arm reach forward for the depth and the arm
span for the length of the table-top where the stove was placed. Meanwhile the stature and shoulder height
were used for estimating the position of the overhead compartment or placement of cooking utensils.
The 5
th
percentile was chosen since it is appropriate to accommodate 90% of the studied population. The 5
th
percentile was also applied for the setting
of the working envelope so as to provide better
reaching tolerances. Meanwhile, standard was used
to compare the present state of the studied kitchen
setting. The results show that 56.4% of the elderly
waist height is lower than the standard table-top
height which is 36 inches (91.4cm) and 36.4% of the stove height was found higher than that of the standard. This could apparently cause fatigue and
discomfort to shoulders, the neck, the arm and the back of the user. Anthropometrics measurements can
be used for estimating the stove height, length and depth. These could also calculate a space taken for
certain physical activities, such as frying task envelope. Providing a good combination of stove height,
length, depth and ergonomic working envelope could hopefully improve the elderly cooking task and
increase their quality of life.
Titanium alloy (e.g. Ti-6Al-4V) has an excellent combination of properties. However in many cases,
the application is limited because of the poor wear property. In this work, a surface modification
(plasma nitriding) is carried out to improve the surface properties of Ti-6Al-4V, as a treatment prior to a hardcoating deposition, leading to a duplex coating system. This is an effort to improve the surface and near surface property of Ti-6Al-4V. Plasma nitriding is performed utilizing microwave plasma method in 25% Ar- 75% N2 atmosphere at temperatures of 600°C and 700°C for different processing times (1, 3 and 5 hours). The phase and microstructure of plasma nitrided substrate were characterized by using X-ray diffraction (XRD) and Scanning electron microscopy (SEM). The plasma nitrided Ti-6Al-4V properties (surface roughness, surface hardness and case depth) were determined using profilometer and microhardness, respectively. Results obtained showed a significant increase on the surface hardness of Ti-6Al-4V. This is due to the formation of TiN and Ti2N phases in the form of compound layer. Besides, it shows that the diffusion of nitrogen into the Ti-6Al-4V substrate produces case depth up to 130 µm and this contributes to the improvement of the near surface hardness due to the changes in the microstructures. It was also found that the surface hardness and surface roughness increased with the increases in the process temperature and times.
The motion resistances of 660 mm pneumatic and rigid bicycle wheels of the same rim diameter were measured experimentally using the developed tractor-towed single non-lug narrow wheel motion resistance test rig for traction studies. The motion resistances measured were taken to be the towing forces determined in real time using Mecmesin Basic Force Gauge (BFG 2500). The test variables included two test surfaces [tilled and wet (mud) surfaces], the dynamic load and the towing velocity. The tyre inflation pressure of 414 kPa was chosen to make the surface synonymous with that of the rigid wheel. Motion resistance ratios of the two wheels were determined empirically and through semi-empirical approach. The motion resistances of the rigid wheel were found to be greater than those of the pneumatic wheel for both surfaces. Consequently, the motion resistance ratios of the rigid wheel were greater than those obtained
from the pneumatic wheel. Analysis of variance showed that there were significant differences between the means of the motion resistance measured on the test surfaces, as well as between the two wheels and their interactions with the test surfaces. The motion resistance ratio exhibited a linear relationship with the towing velocity, while the relationship with the dynamic load was quadratic. However, such a relationship is either direct or inverse with the respective variables. The motion resistance ratio models for the pneumatic and rigid wheels showed that on different test conditions of the dynamic loads and the towing velocities, the relationships between the motion resistance ratio and the dynamic load, and motion resistance with dynamic load were also different.
In this study, a polluted site at Kg. Pasir Puteh was assessed for heavy metal pollution by using
transplanted caged mussel (Perna viridis) from a relatively clean population, Sg. Melayu; both are located in the Strait of Johore. For control purposes, the P. viridis from Kg. Pasir Puteh were also simultaneously transplanted in Sg. Melayu at the same time. It was found that Zn was the metal which got accumulated fastest in the transplanted mussel while Cd was the slowest. This study indicated that the byssus of Perna viridis was most effective for biomonitoring of Cd, Ni, Pb and Zn, while the shell could be used for the biomonitoring of Cu, Ni and Pb and the total soft tissue for the biomonitoring of Ni since they were able to accumulate and eliminate the respective metals well. By using mussel as a biomonitor, the present study found that Kg. Pasir Puteh, which is located in the eastern part of the Strait of Johore, had significantly higher contamination and bioavailabilities of Cd, Cu, Fe, Ni, Pb and Zn. Therefore, the use of the transplanted caged mussels is very useful for heavy metal assessment purposes since it can increase the validity of data interpretation by minimizing ecological factors.
Bismuth chromium solid solutions, with a general formula Bi6-xCr2Oδ, where -1 ≤ x ≤ 2, were successfully synthesized via the conventional solid state method. The phases of the synthesized samples were determined by X-ray diffraction (XRD) analysis. The properties of single-phase compounds were characterized by using differential thermal analysis (DTA), thermal gravimetric analysis (TGA), AC impedance spectroscopy, and inductively coupled plasma-atomic emission spectroscopy (ICP-AES). The occurrence of phase transitions was confirmed by DTA and TGA, where a thermal event was observed by DTA at around 800oC. In addition, TGA studies also showed that there was a weight loss at around 800oC. Elemental analysis of Bi6Cr2O15 and its solid solutions by ICP-AES showed a good agreement between the expected value and the experimental value on the compositions, with no evidence of any systematic deviation from stoichiometric. Electrical properties of Bi6Cr2O15 and its solid solutions were investigated by using AC impedance spectroscopy from 300oC to 650oC. Ionic conductivity increased with the increasing temperature and bismuth content, and the best ionic conductivity was observed for Bi7Cr2O16.5. The activation energy (Ea) of Bi6Cr2O15 and its solid solutions were in the range of 1.22-1.32 eV.
Palm oil-based Trimethylolpropane ester (TMP ester), with an iodine value of 66.4 g/100g, was epoxidizedto produce epoxidized TMP esters. In situ epoxidation method was used with peracetic acid to eliminatefatty acid double bonds in palm oil-based TMP ester and change it into oxirane ring. This was done toimprove the oxidative stability of trimethylolpropane ester which is a key concern limiting the usefulservice life in lubricants. The epoxidation was performed by reacting acetic acid as active oxygen carrierwith concentrated hydrogen peroxide as oxygen donor and a small amount of homogeneous catalyst(sulphuric acid). The effects of various parameters on the rate of epoxidation (such as the ratio of moleacetic acid to ethylenic unsaturation, hydrogen peroxide to ethylenic unsaturation and acetic acid moleratio, and amount of catalyst) were studied. The rate of oxidation was investigated by the percentageof oxirane oxygen analysis and iodine value.
The presence of heavy metals in aquatic systems has become a serious problem. Heavy metals can haveadverse effects on the environment as well as on human health. As a result, much attention has beengiven to new technologies for removal of heavy metal ions from contaminated waters. In this study,Microwave Incinerated Rice Husk Ash (MIRHA), a locally available agricultural waste, was used for theremoval of Cd (as a representative heavy metal) from synthetic wastewater by batch adsorption process.The effects of pH, initial metal concentration, and contact time on Cd removal efficiency were studied.pH 4 was found to be the optimum. The removal efficiency was found to be correlated with the initialmetal concentration and contact time between adsorbent and adsorbate. Cd adsorption kinetics followedthe pseudo-second-order model and implied chemisorption. The adsorption equilibrium of Cd can bewell described by the Freundlich isotherm model.
Hard rock formations consisting of granite and metasedimentary rocks in Peninsular Malaysia, have beenconsidered to be of poor aquifers. The map of shows the area underlain by hard rock as having poorto moderate potential for groundwater production (
A GIS-based user-interface programme was developed to compute the geospatial Water ProductivityIndex (WPI) of a river-fed rice irrigation scheme in Northwest Selangor, Malaysia. The spatial analysisincludes irrigation blocks with sizes ranging from 20 to 300 ha. The amount of daily water use for eachirrigation block was determined using irrigation delivery model and stored in the database for both mainseason (August to December) and off season (February to May). After cut-off of the irrigation supply,a sub-module was used to compute the total water use including rainfall for each irrigation block. Therice yield data for both seasons were obtained from DOA (Department of Agriculture, Malaysia) of thescheme. Then, the Water Productivity Index (WPI) was computed for each irrigation block and spatialthematic map was also generated. ArcObjects and Visual Basic Application (VBA) programminglanguages were used to structure user-interface in the ArcGIS software. The WPI, expressed in termsof crop yield per unit amount of water used (irrigation and effective rainfall), ranged from 0.02 to 0.57kg/m3 in the main season and 0.02 to 0.40 in off season among irrigation blocks, respectively. Thedevelopment of the overall system and the procedure are illustrated using the data obtained from thestudy area. The approach could be used to depict the gaps between the existing and appropriate watermanagement practices. Suitable interventions could be made to fill the gaps and enhance water useefficiency at the field level and also help in saving irrigation water through remedial measures in theseason. The approach could be useful for irrigation managers to rectify and enhance decision-makingin both the management and operation of the next irrigation season.
Covalently cross-linked nanogels were prepared via irradiation of inverse micelles that had been preparedfrom radiation crosslinkable polymer, water, oil and surfactant. A mixture of polymer, water, heptane andsodium dioctyl sulfosuccinate (AOT) at certain compositions forms inverse micelles with the size rangingfrom 2 to 8 nm. The hydrophilic head of the surfactant facilitates encapsulation of water soluble polymer.If the entrapped polymer is radiation crosslinkable, it is expected that upon irradiation, polymerizationshall take place in such small and confined space, leading to formation of nano-sized polymeric gel.Meanwhile, emulsion at 2 nm size was chosen for gamma irradiation process. The formation of thenano-sized discreet gel using irradiation of inverse micelles technique was proven at a dose as low as 5kGy to obtain nanogel sized ~ 95 nm.
A study on the effects of alkali treatment and compatibilising agent on the tensile properties of pineappleleaf fibre (PALF) reinforced high impact polystyrene (HIPS) composite is presented in this paper. Thetensile properties of natural fibre reinforced polymer composites are mainly influenced by the interfacialadhesion between the matrix and the fibres. In this study, several chemical modifications were employedto improve the interfacial matrix-fibre bonding and this resulted in the enhancement of tensile propertiesof the composites. In this study, the surface modification of pineapple fibre with alkali treatments andcompatibilizer were used to improve the adhesion between hydrophilic pineapple fibre and hydrophobicpolymer matrix. There are two concentrations of NaOH treatments and compatibilizer used in this study,namely, 2 and 4 wt. %. The results show that the alkali treated fibre and the addition of compatibilisingagent in PALF/HIPS composites have improved the tensile strength and tensile modulus of the composites.
Numerical studies of blood flow system of aorta coronary sinus conduit were carried out using ANSYSTMCFD simulation. A different model of conduit, which differs in the inlet diameter, was investigated. Theinvestigated inlet diameters are 3 mm, 4 mm and 5 mm. Pressure drop from 80 mmHg to 15 mmHgwas achieved for all the models. The comparison chart was produced to compare the pattern of pressurereduction as well as velocity distribution in each model. From the analysis of coronary sinus conduit,it was found that a narrow tube needs to be incorporated into the conduit produced. This is to inducea venturi effect to reduce the pressure drop of blood within a specific throat length. As conclusion, amodel of 3 mm inlet and a throat diameter of 1.13 mm show satisfactory result for pressure reductionfrom 80 mmHg to 15 mmHg. This particular model also has a lower peak velocity at the inlet zone ofthe throat section, which is more preferable in terms of Reynolds number.
Assembly line balancing is well-known in mass production system but this problem is non-deterministicpolynomial-time(NP)-hard, even for a simple straight line. Although several heuristic methods havebeen introduced and used by researchers, knowing and using an effective method in solving these typesof problems in less computational time have a considerable place in the area of line balancing problem.In this research, a new heuristic approach, known as critical node method (CNM), was introduced andtested by solving several test problems available in the literature so as to solve straight assembly lines.Finally, the obtained results are compared with 9 other heuristic rules in some performance measures.Thus, it is concluded that the proposed CNM is better than the rest in all the measures.
Biocellulose (BC), produced by Acetobacter xylinum (0416), was carried out using three types of medium
composition under static surface culture. The media used in this experiment included CWHSM (Coconut
water in Hestrin-Schramm medium), CM (Complex medium) and HSM (Hestrin-Schramm medium).
CWHSM and CM used coconut water from agro-waste as the main source of sugar. The fermentation
was conducted for 12 days and the results of BC dry weight, cell entrapped, pH medium and productivity
were evaluated and compared. The results show that CWHSM is the most suitable medium for BC
production with a productivity of up to 0.044 g l
-1
day
-1
.
In this paper, an implicit 2-point Block Backward Differentiation formula (BBDF) method was considered for solving Delay Differential Equations (DDEs). The method was implemented by using a constant stepsize via Newton Iteration. This implicit block method was expected to produce two points simultaneously. The efficiency of the method was compared with the existing classical 1-point Backward Differentiation Formula (BDF) in terms of execution time and accuracy.
Carbon monoxide (CO) is a ubiquitous, an indoor and outdoor air pollutant. It is not a significant greenhouse gas as it absorbs little infrared radiation from the Earth. It is produced by the incomplete combustion of fossil fuels, and biomass burning. The CO data are obtained from Atmospheric Infrared Sounder (AIRS) onboard NASA’s Aqua satellite. The AIRS provides information for several greenhouse gases, CO2, CH4, CO, and O3 as a one goal of the AIRS instrument (included on the EOS Aqua satellite launched, May 4, 2002) as well as to improve weather prediction of the water and energy cycle. The results of the analysis of the retrieved CO total column amount (CO_total_column_A) as well as effective of the CO volume mixing ratio (CO_VMR_eff_A), Level-3 monthly (AIR*3STM) 1º*1º spatial resolution, ascending are used to study the CO distribution over the East and West Malaysia for the year 2003. The CO maps over the study area were generated by using Kriging Interpolation technique and analyzed by using Photoshop CS. Variations in the biomass burning and the CO emissions where noted, while the highest CO occurred at late dry season in the region which has experienced extensive biomass burning and greater draw down of CO occurred in the pristine continental environment (East Malaysia). In all cases, the CO concentration at West Malaysia is higher than East Malaysia. The southeastern Sarawak (lat. 3.5˚ - long. 115.5˚) is less polluted regions and less the CO in most of times in the year. Examining satellite measurements revealed that the enhanced CO emission correlates with occasions of less rainfall during the dry season.
Melaleuca cajuputi and Acacia auriculiformis trees are major sources of nectar and pollen for Apis dorsata and the colonies are a major source of honey to the rural poor, honey hunters. Honey is a supplementary income to many of these people (including school children) in the Marang district, Terengganu. In this study, Marang area with 270 square kilometers was chosen as pilot study area in Terengganu state for mapping M. cajuputi and A. auriculiformis as two dominant species in low land secondary forest in Terengganu state.To inventory and produce land use map of Melaleuca forest in Marang area, in this study SPOT-5 satellite image in multispectral mode with 10 meter resolution which is acquired in 2007 as optical satellite was utilized. Most images from optical satellites have some null data from ground because of clouds and shadow of clouds. To solve this problem, Hue, Saturation and value (HSV) and Principal Component Analysis (PCA) were used as fusion techniques to replace null data with microwave data which taken from Radarsat-1 image in C-band with 25 meter resolution image. Accordingly, fusion technique which was used in this research not only was a technique to improve information but also caused the accuracy increasing than land use map by just only SPOT-5 image. Also between two different fusion techniques, PCA shows the better result than HSV as two different fusion techniques.
Geographical Information Systems (GIS) and three dimensional (3D) World Wide Web (WWW) applications usage are on the rise. The demand for online 3D terrain visualization for GIS data has increased. Current users demand for more complex data which have higher accuracy and realism. This is aided by the emergence of geo-browsers in the market which provide free service and also cater for the commercialized market. Other new technology driving the market is the use of software such as CityGML, Virtual Reality Markup Language (VRML)/ Entensive 3D (X3D), geoVRML, and Keyhole Markup Language (KML). These technologies also play an important role for this new era of online 3D terrain visualization. The aim of this paper is to implement the online 3D terrain visualization for GIS data by using VRML technology and launching the system into three different web servers. The data used for this system are contour data and high resolution satellite image (QUICKBIRD) for Universiti Putra Malaysia (UPM) area. Testing was done only for satellite image overlaid to 3D terrain data. The web servers used in this experiment were the Spatial Research Group Server in UPM, Universiti Utara Malaysia (UUM) web server, and ruzinoor.my web server. The comparison was based on the performance of web servers in terms of accessibility, uploading time, CPU usage, frame rate per second (fps), and number of users. The results from this experiment will be of help and guidance to the developers in finding the right web servers for the best performance on implementing online 3D terrain visualization for GIS data.