Space Vector Pulse Width Modulation (SVPWM) method is widely used as a modulation technique
to drive a three-phase inverter. It is an advanced computational intensive method used in pulse width modulation (PWM) algorithm for the three-phase voltage source inverter. Compared with the other PWM techniques, SVPWM is easier to implement, thus, it is the most preferred technique among others. Mathematical model for SVPWM was developed using MATLAB/ Simulink software. In this paper, the interface between MATLAB Simulink with the three-phase inverter by using Arduino Uno microcontroller is proposed. Arduino Uno generates the SVPWM signals for Permanent Magnet Synchronous Motor (PMSM) and is described in this paper. This work consists of software and hardware implementations. Simulation was done via Matlab/Simulink software to verify the effectiveness of the system and to measure the percentage of Total Harmonic Distortion (THD). The results show that SVPWM technique is able to drive the three-phase inverter with the Arduino UNO.
To investigate the pattern and major causes of tooth extraction among patients
attending IIUM Kulliyyah of Dentistry Polyclinic. (Copied from article).
For the past few years, government-funded universities in Malaysia faced an uphill
battle to strategize their management budget due to significant budget cut by the
Malaysian Government. One portion of the budget will be spent towards achieving the
key performance indicators (KPIs) set by the universities to achieve their annual
targets. Unfortunately, some universities set up their specific strategies to achieve the
KPIs without ample consideration to the limited available resources where less
attention is channeled to the cost of achieving the KPIs. Setting priorities and making
decisions on allocation and reallocation of resources based on the direction of the
strategies must be executed with transparency and accountability and will be of great
importance. In this paper we illustrate how integer programming was applied to
allocate budget based on the KPIs set for one of the government-funded Malaysian
universities’ (U-XYZ’s) research and publication agenda. Two models were developed
and successfully solved. The first model was to determine the total budget needed if
all the KPIs were to be achieved while the second model was to distribute the allocated
budget set by U-XYZ, for all the activities planned for the agenda. The result showed
that in order to achieve the target, U-XYZ has to increase its budget allocation by
RM2.164 million. Otherwise, U-XYZ can only expect to obtain 1.578 out of 1.593 points
that is required to be achieved.
Melissopalynology (pollen analysis) allows the identification of floral sources, botanical and geographical origin of selected Kelulut honey samples. Therefore, the aim of this study is to determine the origin of selected Kelulut honey by Geniotrigona thoracica and Heterotrigona itama farmed and harvested at Lenggong (Perak). Briefly, the honey was diluted in ddH2O and filtered to obtain the pollens. Subsequently, the morphology of the pollens was observed under scanning electron microscope (SEM) and the frequency classes of species were determined. Based on qualitative and quantitative analysis, G. thoracica honey was demonstrated to be a uni-floral honey and H. Itama honey as a multi-floral honey. A total of 7 types of pollens were observed in G. thoracica honey while 9 types in H. Itama honey. Some of the pollen were identified with the aid of pollen atlas while some were unidentified. Furthermore, the results obtained in this study suggested that the pollens present in Kelulut honey are crucial in identifying botanical resource of stingless bee honey, which assist in preserving the ecosystem.
The large clinical spectrum of Haemoglobin E (HbE)/β-thalassaemia leads to identification of modifiers that cause the complexity1. IGSF4, a member of the immunoglobulin superfamily 4 is known as a thalassaemia-related gene that plays an important role in globin synthesis. Methylation of IGSF4 was reported to interrupt the process of globin synthesis through its interaction with other genes in the regulation network of globin expression2. Specific cells isolation is needed in order to study the methylation profile as the interaction between various haematopoietic cells including nucleated red blood cells (NRBCs) in whole blood could impact the methylation results3. Therefore, the objective of this study was to describe the pattern of DNA methylation at the promoter region of IGSF4 gene that may involve in the alteration of globin synthesis in HbE/β-thalassaemia patients.
The Malaysian’s PUSPATI TRIGA Reactor (RTP) achieved its initial criticality on June 28, 1982. The reactor is designed to effectively implement various fields of basic nuclear research, manpower training, and production of radioisotopes. Several past activities on neutronics modelling development and validation of the RTP were carried out using Monte Carlo Code MCNP. In this work, the developed model was used to characterise in-core and beam-ports irradiation facilities of the reactor. The thermal and fast neutron flux distributions in these facilities were determined using MCNP mesh tally method. It was found that the flux as well as its spectral characteristics depended very much on the position of the irradiation facility in the reactor core or in the beam-ports. The maximum neutron flux was found to be in the Central Thimble facility with 1.98E13 nv of thermal neutron. The thermal-to-total flux ratio varies significantly from 0.41 for the in-core facility, 0.58 in the reflector and up to 0.88 in the beam-ports.
Austempering is one of the trendiest heat treatment processes to promote the strength and toughness of ductile iron. However, such practice is complex because it involves using aqueous solutions as quenchant (salt bath solution). This study was conducted to analyse the heat treatment of the combination processes of annealing-austenitising and evaluate the correlation between microstructure constituent and hardness of the ductile iron. Ductile iron samples in form of double cylinder was produced by conventional CO2 sand casting method. The new heat treatment process was started by annealed at 873 K for 1.8 ks before being oil quenched. Subsequently, the samples were austenitised at austenitising temperatures 1123 K, 1173 K and 1223 K for 3.6 ks respectively before being immediately oil quenched to room temperature. A series of microstructure analysis tests, including optical microscopy and X-ray diffraction (XRD) was applied. Vickers microhardness tester was used to measure the hardness for each microstructure constituent. The results showed that ductile iron matrix transforms to martensitic during heat treatment of annealing-austenitising combination processes, which in turn contributes to increasing microhardness of martensite and the bulk hardness of ductile iron.
Prolonged drought conditions have adverse environmental and socio-economic impacts due to unmet water demands. Defining drought is difficult because of its onset and ending time. Therefore, characterisation of drought is essential for drought management operations. Thus, drought indices come in handy and are a practical approach to assimilate large amounts of data into quantitative information which can then be applied for drought forecasting, declaring drought levels, contingency planning and impact assessments. This study analyses drought events using indices, namely SPI and Deciles Index, computed with DrinC software program but are not popular in Malaysia. It is observed that both indices are identical and suitable for drought occurrences.
Monthly data about oil production at several drilling wells is an example of
spatio-temporal data. The aim of this research is to propose nonlinear spatio-temporal
model, i.e. Feedforward Neural Network - VectorAutoregressive (FFNN-VAR) and FFNN
- Generalized Space-Time Autoregressive (FFNN-GSTAR), and compare their forecast
accuracy to linearspatio-temporal model, i.e. VAR and GSTAR. These spatio-temporal
models are proposed and applied for forecasting monthly oil production data at three
drilling wells in East Java, Indonesia. There are 60 observations that be divided to two
parts, i.e. the first 50 observations for training data and the last 10 observations for
testing data. The results show that FFNN-GSTAR(11) and FFNN-VAR(1) as nonlinear
spatio-temporal models tend to give more accurate forecast than VAR(1) and GSTAR(11)
as linear spatio-temporal models. Moreover, further research about nonlinear spatiotemporal
models based on neural networks and GSTAR is needed for developing new
hybrid models that could improve the forecast accuracy.
PHAs (polyhydroxyalkanoates) have emerged as biodegradable plastics more strongly in the 20th century. A wide range of bacterial species along with fungi, plants, oilseed crops and carbon sources have been used extensively to synthesize PHA on large scales. Alteration of PHA monomers in their structures and composition has led to the development of biodegradable and biocompatible polymers with highly specific mechanical properties. This leads to the incorporation of PHA in numerous biomedical applications within the previous decade. PHAs have been fabricated in various forms to perform tissue engineering to repair liver, bone, cartilage, heart tissues, cardiovascular tissues, bone marrow, and to act as drug delivery system and nerve conduits. A large number of animal trials have been carried out to assess the biomedical properties of PHA monomers, which also confirms the high compatibility of PHA family for this field. This review summarizes the synthesis of PHA from different sources, and biosynthetic pathways and biomedical applications of biosynthesized polyhydroxyalkanoates.
The best commonly applied approach in seating ergonomics is the concept that the seat must fit the sitter.
Understanding of population anthropometry is necessary because, in the mass vehicle market, a single seat should fit
a huge portion of the population. This research work proposes some automotive seat fit parameters based on a
representative Nigerian anthropometric data, to ensure an optimum fit between the vehicle seats and the occupants,
as well as providing adequate accommodation. Anthropometric data of 863 Nigerians captured with special emphasis
on the dimensions that are applicable in automotive seat design. A comparison made between the data obtained and
that of five other countries. The proposed dimensions includes: seat cushion width (475mm); seat cushion length
(394mm); seat height (340mm); seat lateral location (583mm); seat back height (480mm); seat back width (427mm);
armrest height (246mm); headrest height (703mm); armrest surface length (345mm); backrest width (thoracic level)
(524mm); seat adjustment (186mm); backrest width (lumbar level) (475mm) and distance between armrests
(475mm). A comparison made between the proposed dimensions and those recommended by four other scholars for
other populations. Finally, an ergonomic automotive seat suitable for the Nigerian population was designed using
AutoCAD 2016 software based on the proposed established dimensions.
Anthropometric study is one of the oldest branches of study in ergonomics where it serves a purpose in study of
proportion and size for human body. One of the common methods used in anthropometric measurement is traditional
measurement or direct measurement. However, Malaysia is still left behind other countries in development of national
anthropometric database. Researchers in Malaysia are still relying on the traditional anthropometric (TA)
measurement. There are several important factors that contribute to problems in TA such as accuracy, time, posture,
identification of landmarks, instrument positions and orientations, and pressure exerted due to measuring equipment. In
view of the fact that the difficulties of obtaining human anthropometry, it becomes necessary to propose a method which
has less contact executed to respondent. This study aims to propose a new anthropometric measurement method using
motion capture camera (MCC) method, later to develop the database for youth male population. A pilot test was done
in order to confirm the measuring procedure as well as the flow of the study. Next, the Minitab statistical software used
to check the validity and reliability of data using the tests of a) Accuracy-Pearson/Spearman Correlation b) BiasPaired
T-Test c) Test-Retest Reliability-Pearson/Spearman Correlation d) Precision-Mean Absolute Difference and
Relative Error Measurement. Results showed that the validity and reliability of this motion camera has successfully
obtained and the anthropometric data for youth male respondents has successfully constructed. These findings can be
used and expended to the national anthropometric database to be utilised in ergonomics design.
The effect of mixed strain culture of lactic acid bacteria (LAB) and Yeast, and yeast or L.
brevis, L. plantarum, or L. sanfranciscencis on the physicochemical properties (pH, TTA,
organic acid, ethanol, and sugar content) of rice bran sourdough was investigated. Starter
culture with optimum physicochemical properties was used to ferment rice and wheat bran
for sourdough production. Rice and wheat bran sourdough and non-fermented rice and
wheat bran were mixed with wheat flour at 10% substitution level for bread production.
Results showed that rice bran fermented with L. plantarum had the best physicochemical
properties compared to rice bran sourdough produced by other LAB or mixed culture. The
specific volume of bread sample made with rice bran sourdough (4.65 cm3
/g) was higher
than that of the bread samples made from wheat bran sourdough (4.32 cm3
/g) and nonfermented
bran (3.74 – 4.24 cm3
/g), but not significantly different from the control (100%
wheat) bread (4.85 cm3
/g). The crumb colour of the rice bran and rice bran sourdough
substituted bread was lighter than that of the other bread samples. Crust colour of all the
bread samples was not significantly different (p > 0.05). At the end of 6 days storage
period, bread samples from control and wheat bran sourdough were firmer than that from
rice bran sourdough, however, crumb firmness values were highest in non-fermented bran
substituted bread. Sensory analysis result revealed that rice bran sourdough bread was
more acceptable than wheat bran sourdough bread, and non-fermented rice and wheat bran
substituted bread.
As a way to enhance performance in sports, apart from in-field or in court training, athletes are recommended to adopt resistance training into their training routine. As an exercise that needs the performer to split their legs, lunge is suggested to be included as an exercise in a training session. Various researches had been conducted on lunge and several findings showed different methods or protocols of lunge affect the kinematics, kinetics muscle activation and fascicle behaviour response during the exercise. Although not much study conducted on the chronic adaptations, the existing studies suggested that performers should well plan the training protocols as this will cause different training adaptations.
Synthetic fibers such as glass fiber and carbon fiber are traditionally used as reinforcement in engineering composites. The increasing of environmental concerns has led to the use of natural fibers as renewable alternatives reinforcement. Among them, coconut meat husk fiber which abundant availability can be used as reinforcement fiber. However, the coconut meat husk fiber, same as other natural fibers, has the issues of fiber/matrix bonding and moisture absorption. Chemical treatments are needed to modify the surface of fiber, aiming at improving the adhesion with polymer matrix and reducing the hydrophilicity of the fiber. Alkalization was used in this study to treat the coconut meat husk fiber. The effects of chemical treatments for 1hr and 24 hr treatment time on the coconut meat husk fibers reinforced composites were investigated. A result showed that the 24 hr alkali treatment gave the highest tensile stenght compared to the 1hr treatment and RO water.
Osteomyelitis refers to an infection of the bone characterized by progressive inflammatory destruction caused by infecting microorganism. Open fracture carries the risk of developing osteomyelitis from 3 to 50% with a high amputation rate. Salvage of the limb is always a challenge and needs perseverance. We report the case of a 44-year-old male with chronic osteomyelitis with successful multiple limb salvage surgeries. The curative approach to chronic osteomyelitis has the following goals including arrest of infection, pain reduction and salvage of limb and function. With regard to survival and function, the result obtained in this case is more promising compared to above knee amputation.
Laryngopharyngeal tuberculosis (TB) is a rare disease and usually associated with pulmonary tuberculosis. Mostly, it occurs in adults without BCG vaccination or in immuno-compromised patients (such as AIDS patients). A 34-year-old gentleman with odynophagia and poor oral intake was referred to us to rule out malignancy. Direct laryngoscopy examination revealed ulcerative lesion involving right tonsillar fossa extending downward till right pyriform sinus. Panendoscopy and biopsy was performed. Laryngopharyngeal TB was diagnosed based on the histopathological examination and Ziehl-Neelsen staining.
Rainfall is an interesting phenomenon to investigate since it is directly related
to all aspects of life on earth. One of the important studies is to investigate and under-
stand the rainfall patterns that occur throughout the year. To identify the pattern, it
requires a rainfall curve to represent daily observation of rainfall received during the year.
Functional data analysis methods are capable to convert discrete data intoa function that
can represent the rainfall curve and as a result, try to describe the hidden patterns of the
rainfall. This study focused on the distribution of daily rainfall amount using functional
data analysis. Fourier basis functions are used for periodic rainfall data. Generalized
cross-validation showed 123 basis functions were sufficient to describe the pattern of daily
rainfall amount. North and west areas of the peninsula show a significant bimodal pattern
with the curve decline between two peaks at the mid-year. Meanwhile,the east shows uni-
modal patterns that reached a peak in the last three months. Southern areas show more
uniform trends throughout the year. Finally, the functional spatial method is introduced
to overcome the problem of estimating the rainfall curve in the locations with no data
recorded. We use a leave one out cross-validation as a verification method to compare
between the real curve and the predicted curve. We used coefficient of basis functions
to get the predicted curve. It was foundthatthe methods ofspatial prediction can match
up with theexistingspatialpredictionmethodsin terms of accuracy,but it isbetterasthe new
approach provides a simpler calculation.
Non-alcoholic fatty liver disease (NAFLD) is a clinicopathological syndrome strongly associated with
hyperlipidemia, hypertriglyceridemia, insulin resistance and obesity. The objective of this study is to evaluate the
potential health benefits of Baccaurea angulata fruit in preventing liver damage due to hypercholesterolemia.
Twenty-five healthy adult New Zealand White rabbits were assigned to five groups for 90 days diet and
intervention plan. While four groups (atherogenic groups) were fed 1% cholesterol diet and 0, 0.5, 1.0, and 1.5 mL
of B. angulata juice kg/per day, the fifth group (negative control) was fed with commercial rabbit pellet only.
After overnight fasting and sacrifice, the thoracic cavity was opened and the liver was carefully removed,
specifically observing for any presence of a gross lesion and then immediately fixing in 4% paraformaldehyde for
at least 48 hours for histopathological analysis. The hepatoprotective effect of B. angulata fruit juice was evident
in the histological examination of liver tissues. The results indicate the potential health benefits of the antioxidantrich
B. angulata fruit juice as a functional food with a therapeutic effect against hypercholesterolemia-induced
liver injury.