Palm oil (PO) and fully hydrogenated palm oil (FHPO) were subjected to enzymatic
interesterification using 9.5% of TLIM Lipozyme. The optimum condition for this process
occurred at 62.75°C, with reaction time 172.50 minutes with the ratio of 1:1 for palm oil to
hydrogenated palm oil respectively. The Palmitoyl-Oleoyl-Stereoyl (POS) yield obtained
was approximately 15%. Product was subsequently subjected to a fractionation process
at various cooling temperatures and reaction time. At 34°C, POS achieved was at the
highest level which was approximately 31% after 12 hours cooling process. The study of
physiochemical properties of the Cocoa butter Equivalent (CBE) fat was determined for the
purpose of characterization identification. The properties identified were solid fat content,
slip melting point (SMP) and iodine value (IV). The IV and SMP values obtained were
44.30 and 29°C respectively. However, CBE produced almost 0% of Solid Fat Content
(SFC) at 30°C. Apart from the high yield of POS, the physicochemical characteristics
showed significant compatibility with that of CB. In addition, the crystal polymorph of
CBE 34 physicochemical characteristics of CBE34 (β′+β) was similar to CBE. Hence, from
this study, CBE 34 is recommended for utilization in the confectionery industry as CBE.
Autocorrelation problem causes unduly effects on the variance of Ordinary Least Squares (OLS) estimates. Hence, it is very essential to detect the autocorrelation problem so that appropriate remedial measures can be taken. The Breusch-Godfrey (BG) test is the most popular and commonly used test for the detection of autocorrelation. Since this test is based on the OLS estimates, which are not robust, it is easily affected by outliers. In this paper, we propose a robust Breusch-Godfrey (MBG) test which is not easily affected by outliers. The results of the study indicate that the MBG test is more powerful than the BG test in the detection of autocorrelation problem.
Expectation Maximization (EM) algorithm has experienced a significant increase in terms of usage in many fields of study. In this paper, the performance of the said algorithm in finding the Maximum Likelihood for the Gaussian Mixed Models (GMM), a probabilistic model normally used in fraud detection and recognizing a person’s voice in speech recognition field, is shown and discussed. At the end of the paper, some suggestions for future research works will also be given.
It is now evident that the estimation of logistic regression parameters, using Maximum LikelihoodEstimator (MLE), suffers a huge drawback in the presence of outliers. An alternative approach is touse robust logistic regression estimators, such as Mallows type leverage dependent weights estimator(MALLOWS), Conditionally Unbiased Bounded Influence Function estimator (CUBIF), Bianco andYohai estimator (BY), and Weighted Bianco and Yohai estimator (WBY). This paper investigates therobustness of the preceding robust estimators by using real data sets and Monte Carlo simulations. Theresults indicate that the MLE behaves poorly in the presence of outliers. On the other hand, the WBYestimator is more efficient than the other existing robust estimators. Thus, it is suggested that the WBYestimator be employed when outliers are present in the data to obtain a reliable estimate.
Waste rocks are a non-economical by-product of mining operations, which can lock up carbon dioxide into a carbonate form and thereby help reduce greenhouse gases emissions. The aims of this research are to determine the mineral and chemical composition of the sedimentary waste rocks of gold mines and to classify the potential of silicate minerals to be a feedstock for carbonation mineralization. The sampling was undertaken at the Selinsing gold mine, where waste rocks were collected from the waste dump, stockpiles, the borrow pit, and the main pit. The mineralogical and chemical component of the sedimentary waste rocks were explored using X-ray diffraction and energy dispersive X-ray spectroscopy. The findings indicated that the presence of divalent cations, of 55.12% for CaO, 9.09% for MgO, and 16.24% for Fe2O3 from gold mine waste, capable of sequestering carbon dioxide into calcium, magnesium and iron carbonates, respectively, through carbonation of mineral. The domination of silicate minerals such as quartz, muscovite, kaolinite, chlorite, albite, and carbonate minerals such as calcite, have been found to be widespread in sedimentary waste rocks. However, the natural silicates (chlorite, muscovite) and carbonates (calcite) are potential minerals which can be consumed as feedstock for carbonation processes because they contain the magnesium, iron, and calcium elements which can form stable carbonates in the presence of carbon dioxide. The mineralogy and chemical composition of sedimentary waste rocks from the Selinsing gold mine provides a better understanding of the future carbonation reaction to sequester more carbon dioxide in response to climate change.
The objective of this study was to explore the geographic distribution and temporal patterns of violent crime cases in Peninsular Malaysia by using the tools and techniques for spatial analysis. This study will also provide a general picture of violent crime patterns in Malaysia. The unit of analysis is district and the violent crime data from the year 2000 until 2009 were used in this study. In order to obtain the optimum number of components of crime in the space-time period, the space-time Normal Mixture Models were used. Based on the results of this model, the mapping of the crime occurrences was made. This map displays the spatial distribution of crime occurrence in 82 districts of Peninsular Malaysia. From this analysis, more violent crimes were shown to have occurred in developed states such as Selangor, Wilayah Persekutuan Kuala Lumpur and Johor. The findings of this study could be used by policy makers or responsible agencies to take any relevant actions in terms of crime prevention, human resource allocation and law enforcement so as to overcome this important issue in future.
The purpose of this research is to analyse the influence of change management and e-learning in Malaysian private higher education institutions focusing on educators’ perspectives. The conceptual framework was modified in combination of various theories from Systemic Change Models and E-learning Cycle Models. A self-administered questionnaire adapted from Siebel 4.0-2 Survey Questionnaires (SSQ) by Hambling, 2010 was the data collection instrument. The sample consisted of educators from private higher education institutions with visions or missions based on e-learning implementation in Malaysia. As per findings, through review of the visions and missions, the selected private higher education institutions integrated teaching and learning with Stepwise Multiple regression analysis, has a significant relationship on independent variables that contribute to e-learning implementation.
Strength and durability are important characteristics of concrete and desired engineering properties. Exposure to aggressive environment threatens durability of concrete. Previous studies on bio-concrete using several types of bacteria, including sulphate reduction bacteria (SRB), had to increase durability of concrete have shown promising results. This study used mixtures designed according to concrete requirement for sea water condition with SRB composition of 3%, 5% and 7% respectively. The curing time were 28, 56 and 90 days respectively. The mechanical properties, namely compressive strength and water permeability, were tested using cube samples. The results showed compressive strength had higher increase than the control at 53.9 Mpa. The SRB with 3%composition had maximum water permeability. Thus, adding SRB in concrete specimens improves compressive strength and water permeability. This is particularly suitable for applications using chloride ion penetration (sea water condition) where corrosion tends to affect durability of concrete constructions.
Nowadays, Concurrent Engineering (CE) is becoming more important as companies compete in the worldwide market. Reduced time in product development process, higher product quality, lower cost in manufacturing process and fulfilment of customers’ requirements are the key factors to determine the success of a company. To produce excellent products, the concept of Concurrent Engineering must be implemented. Concurrent Engineering is a systematic approach which can be achieved when all design activities are integrated and executed in a parallel manner. The CE approach has radically changed the method used in product development process in many companies. Thus, this paper reviews the basic principles and tools of Concurrent Engineering and discusses how to employ them. Similarly, to ensure a product development process in the CE environment to run smoothly and efficiently, some modifications of the existing product development processes are proposed; these should start from market investigation to detail design.
Rainfall is one of the microclimatic variables that vary with space. The changes in vegetation characteristics may influence the microclimate elements. To demonstrate rainfall variation due to vegetation, the relationship between rainfall and vegetation should be spatially investigated over a local scale. This paper aims to explore the impact of vegetation on local variations of rainfall based on Geographically Weighted Regression (GWR) approach. The global and local relationship between rainfall and the extracted Normalized Difference Vegetation Index (NDVI) of Landsat 7 ETM+ are quantitatively estimated in 2000 and 2011 within the northern and east coast regions of the Peninsular Malaysia. Based on 277 rainfall stations, the Moran’s Index (Moran’s I) spatial autocorrelation and Ordinary Least Square (OLS) - GWR methods were applied to analyse the rainfall spatial patterns and to determine rainfall spatial variation, respectively. It was found that, the rainfall spatial patterns exhibit small clustering patterns which leads to non-stationarity. This indicator supports the use of local regression approach in exploring the variation of rainfall due to vegetation. The R-Squared (R2) from GWR (0.51 and 0.75) significantly improved the R2 from OLS (0.01 and 0.04) for both years. The approach of GWR in the relationship between rainfall and vegetation provides findings on rainfall spatial variation on a local scale.
One of the best ways to enhance heat transfer coefficient is by improving thermal properties of the
working fluid. Gold/water nanofluid flow through horizontal minitube with very low Reynolds number
was simulated by using Thermal Lattice Boltzmann Method (TLBM) under uniform heat flux boundary
condition. The effect of different volume fraction of nanoparticles on the heat transfer coefficient was
studied and compared with the base fluid (water). The results were verified using Finite Volume Method
(FVM). The results showed enhancement of heat transfer coefficient when using gold/water nanofluid
and this enhancement depends on the volume concentration of Gold nanoparticles. The maximum
enhancement was 18% with 0.03 volume concentration.
If we were given a questionnaire of “How do we measure a researcher as a true scientist? with optional answers like (a) Having a good number of publications, (b) having attending numerous conferences, (c) with a high popularity as always appeared in mass media, and (d) good international networking and good public relations. Options (c) and (d) always come later after option (a) has been achieved, while option (b) can be simply achieved or abstract be accepted for presentation in any conference. Hitherto, publishing in any peer-reviewed journals carry a certain quality since they are highly subjected to peer review evaluation before the paper can be accepted for publication in a journal. Needless to say, those constructive comments given by the reviewers are very crucial in shaping our scientific understanding in our subject area rather than rejection experience (Yap, 2009). Having said so, option (a) will definitely be the best answer. The fact is that option (a) should not be argued whatsoever as the best answer [since publications speaks louder than anything else] and options (a), (b) and (c) are supplementary criteria to option (a) but they are not as vital as option (a). When we are asked ‘What is your scientific research performance or research output?’, the answer could always be ‘Having a good number of publications.’ Then, the next question forwarded is that ‘What is the quality and impact of your published papers to the scientific community?’ Of course, good and high impact factor journals always accept papers with high novelty in the subject area. Therefore, papers published in good journals are always highly cited and subsequently resulting in high impact (or citations) of the research done to the scientific community. However, the last question is sometimes very subjective and difficult to answer until h-index is introduced and discussed among the researchers. This paper aimed to discuss the h-index based on Elsevier’s Scopus database as an indicator of research achievement for young Malaysian scientists.
As a crucial demand in urban areas, flood risk management has been considered by researchers and decision makers around the world. In this case, hydrological modelling that simulates rainfall-runoff process plays a significant role. This paper quantified the roles of three main parameters in river basin hydrological response, namely, rainfall event duration, rainfall event ARI (magnitude) and land-use development condition. The case study area of this research was Sungai Kayu Ara basin which is located in the western part of Kuala Lumpur, Malaysia. A total of twenty seven scenario were defined for this research, including three different rainfall event durations (60, 120 and 360 minutes), three different ARIs (20, 50 and 100 years) and in three different land-use conditions (existing, intermediate and ultimate). The results of this research indicate that rainfall event duration, rainfall event ARI (magnitude) and land-use development condition have considerable effects of the surface runoff hydrographs in terms of peak discharge and volume.
Setting a question paper for test, quiz, and examination is one of the teachers’ tasks. The factors that are usually taken into consideration in carrying out this particular task are the level of difficulty of the questions and the level of the students’ ability. In addition, teachers will also have to consider the number of questions that have impact on the examination. This research describes a model-based test theory to study the confidence intervals for the projected number of items of a test, given the reliability of the test, the difficulty of the question, and the students’ ability. Using the simulated data, the confidence intervals of the projected number of items were examined. The probability coverage and the length of the confidence interval were also used to evaluate the confidence intervals. The results showed that the data with a normal distribution, the ratio variance components of 4:1:5 and reliability equal to 0.80 gave the best confidence interval for the projected number of items.
A chemical modifier (acrylic acid) was used to improve the thermal properties of polypropylene/ ethylene propylene diene terpolymer/calcium carbonate (PP/EPDM/CaCO3) composites. Treated
and untreated PP/EPDM composites were filled by CaCO3 at 0, 20 and 40% wt. The composites
were prepared using Z-blade mixer machine at 180oC and 50 rpm of rotor speed. Thermogravimetric
analysis (TGA) and differential scanning calorimetry (DSC) methods were used to analyze the thermal properties of the composites. Thermogravimetric analysis indicated that the total weight loss of PP/EPDM/CaCO3 composites decreased with the increasing filler loading for the treated and untreated composites. Meanwhile, the presence of acrylic acid was found to have increased the thermal stability and crystallinity of PP/EPDM/CaCO3
.
This aim of this study is to study the effects of various contents of Automotive Windscreen Glass Waste Powder (WGWP) as a cement replacement. Mortar incorporating several compositions of WGWP (0%, 5%, 10%, 15% and 20%) by weight of cement was prepared. Three batching systems of cement to sand (C:S) ratios of 1:2.5 superplasticizers (SP), 1:3.0 SP and 1:3.5 SP was also employed. Fixed water to cement (w/c) ratio of 0.5 was used. The samples were water cured and the assessment of the strength performance of mortar cubes carried out at 7 and 28 days. Studies conducted have shown that WGWP has good pozzolanic properties. In term of compressive strength, it was observed that employing C:S ratio of 1:3.5 SP is better than 1:2.5 SP and 1:3.0 SP.
The main focus of this study was to obtain the optimum alkaline treatment for banana fibre and the its effect on the mechanical and chemical properties of banana fibre, its surface topography, its heat resistivity, as well as its interfacial bonding with epoxy matrix. Banana fibre was treated with sodium hydroxide (NaOH) under various treatment conditions. The treated fibres were characterised using FTIR spectroscopy. The morphology of a single fibre observed under a Digital Image Analyser indicated slight reduction in fibre diameter with increasing NaOH concentration. The Scanning Electron Microscope (SEM) results showed the deteriorating effect of alkali, which can be seen from the removal of impurities and increment in surface roughness. The mechanical analysis indicates that 6% NaOH treatment with a two-hour immersion time gave the highest tensile strength. The adhesion between single fibre and epoxy resin was analysed through the micro-droplet test. It was found that 6% NaOH treatment with a two-hour immersion yielded the highest interfacial shear stress of 3.96 MPa. The TGA analysis implies that alkaline treatment improved the thermal and heat resistivity of the fibre.
The presence of airflow during heating process is expected to increase heat uniformity in a closed heating chamber. Circulation of hot air increases the percentage of convective heat transfer. In this study effects of airflow on oven temperature, cake temperature and several cake qualities were investigated. Experimental studies were conducted in convective oven using two different baking modes; with and without airflow. During baking, oven temperatures and internal cake temperature were measured, and images of cake expansion were captured. Results of the study showed that the presence of airflow could maintain the oven temperature within a small range of set point temperature. Temperature in the oven exhibited ±5.5°C fluctuation, approximately 3.5% overshoot that occurred continuously during baking with airflow. On the contrary, higher overshoot (ranging from 15 to 30%) was observed in oven temperature without airflow. Airflow also showed a significant effect (p
Ordinary Portland Cement (OPC) is widely used by the construction industry. Research to find the precise proportion of cement replacement material which can be used to produce a product called Ternary Blended Cement (TBC) is not new. The objective of this study is to determine the effect of POFA and SF as TBC on the heat of hydration and compressive strength of mortar. Before producing TBC, specimens using BBC is required. Mix design proportion for POFA and SF are 5%, 10%, 15%, and 20%. Mix design proportion TBC are chose from the highest compressive strength value achieved at 7 days of curing. This research found the heat of hydration of TBC containing 20% POFA and 5% SF is high in the beginning to drop at the end of hydration process in addition to producing lower compressive strength.
Literature has established the effectiveness of self-regulatory techniques using Heart Rate Variability (HRV)-Biofeedback Technology in improving individual’s heart coherence. The current study aims to evaluate the effectiveness of Quick Coherence Technique, a self-regulatory technique, through the application of HRV-biofeedback technology on the level of heart coherence among university students. A total of 20 students of a technical public university participated in the study. The Quick Coherence Technique (QCT) and the emWave device and software of the HeartMath Institute were used to collect the data. According to the HRV power spectrum, the HRV data is divided under very low frequency (VLF), low frequency (LF), and high frequency (HF) frequency ranges. Based on the results, the use of HRV-biofeedback technology and the QCT had helped to increase the levels of HRV scores and heart coherence of the participants.