In this study, we investigate the ability of the bacterial isolates from an Iraqi oil
reservoir, namely POS and PCO Oil to decolorize commercially used model azo dye Acid
Red-27(AR-27). The effects of inoculation volume and glycerol concentrations were
optimized to develop an economically feasible decolourization process. The isolates
were able to decolourize azo dye (AR27) at the highest decolorization efficiency of 98%
in 10 mL bacterial solution consisted of POS and PCO Oil and in the presence of 6.34
g/L glycerol. An optimized MFC using this bacterial consortium (POS + PCO Oil) and
graphite rod electrodes produced a maximum open circuit voltage (OCV) of 175 mV, in
the presence of potassium ferricyanide as the electron acceptor at the cathode. The
maximum current density of 1.7 μA/cm² and power density of 59.3 μW/cm² were
achieved when an external load of 5 kΩ was applied. Morphological analysis was
performed using Scanning Electron Microscope (SEM) to prove the bacterial
attachment onto the anode surface (graphite rod) in the MFC operation. This work
proposed that the bacterial strains POS and PCO Oil possess the ability to decolorize
Azo dye AR27 and generate electricity in the absence of nitrogen source.
Electrical Discharge Machining, EDM is one of the technologies used for surface
texturing such as the embedded micro-dimples on the metallic acetabular cup. During
the machining process, changes in the gap distance may lead to load changes from
open to short circuit. Limiting the load current under short circuit conditions and load
voltage under open circuit conditions is the requirement in this system. Power supply
is one of the elements that controls the process parameters which is related to improve
the machining condition as well as Material Removal Rate (MRR). A considerable
number of power supply design method were proposed for various EDM application.
This research proposed a Switch Mode Power Supply method implementing new
design of Flyback power supply which can stabilize the voltage during open circuit
condition as well as during discharge condition. Experimental studies were conducted
to verify the capability of Flyback power supply by machining eight micro-dimples in
lower position and twelve micro-dimples in upper position, both in circular
arrangement on metallic acetabular cup. Research conducted shows that the Flyback
power supply improve the consistency of MRR when compared to Linear power supply.
This may help to predict the machining time, thus improving the production of microdimples
in required time.
Value management explicitly targets to optimize value by providing necessary
functions at the least cost without sacrificing quality and performance. However, the
activities/methods of this technique in emerging economies are here and there
related to informal methodology. Therefore, the occurrence of these activities in an
evolving economy requires investigation. The exploration of the extent to which the
measured variables influenced the latent factors informed the need for this study.
Data was retrieved via self-administered questionnaire from 344 registered and
practicing construction professionals in Nigeria. The data was analyzed using SPSS for
descriptive analysis and Structural Equation Modelling (SEM). Kaiser-Meyer-Olkin
measure of sampling adequacy revealed that the internal consistency of the
developed research instrument was appropriate. Confirmatory factor analysis
indicates satisfactory goodness of fit among acknowledged determinants of the
model. Furthermore, the study revealed three (3) phases of the activities/methods of
value management in the Nigerian construction industry which include: information,
information/function analysis, and creativity/evaluation/development/presentation
phases. This means that value management activities and methods are being
practiced in Nigeria, however not as per the typical methodology or standard. The
need to carry out the practice according to the formal value management
methodology is therefore recommended.
As the lighting load constituted amount of power in electricity system, improving of efficiency in lighting technology would make a beneficial to consumer, energy provider and environment. Consequently, majority of home lighting manufacturers were competing each other by improving and claiming their product as the best energy efficient lighting product. Knowledge or exposure regarding to lighting technology especially on energy efficiency, power quality and economy are an important issues to give awareness to user before buy or use the lighting product. Therefore in this research study, three types of lighting product such as energy saving incandescent lighting, compact fluorescent lighting (CFL) and solid state lighting (LED) were compared. Comparative parameters were collected from data provided by lighting manufacturer and experimental data conducted in laboratory using power quality meter and lux meter. Hence, these study discussed in term of economy, power and light quality and energy efficiency of the tested lighting product. At the end of this study, the best home lighting technology is determined successfully.
Phishing detection is a momentous problem which can be deliberated by many
researchers with numerous advanced approaches. Current anti-phishing mechanisms
such as blacklist-base anti-phishing, Heuristic-based anti-phishing does suffer low
detection accuracy and high false alarm. There is need for efficient mechanism to
protect users from phishing websites. The purpose of this study is to investigate the
capability of 6 machine learning algorithms i.e. Multi-Layer Perceptron (MLP), Support
Vector Machine (SVM), Random Forest (RF), Decision Tree (DT), Logistic Regression
(LR) and Naïve Bayes (NB) to classify phishing and non-phishing websites. These
algorithms were trained with two different groups of training in WEKA environment
and then were tested in terms of accuracy, precision, TP rate, and FP rate on a 3
different sets of dataset which contains dissimilar portion of phishing and non-phishing
instances. Results presented that Naïve Bayes classifier has better detection accuracy
between other classifiers for predicting phishing websites while Multi-Layer
Perceptron gave worst result in terms of detection accuracy. The result also showed
that Support Vector machine has better FP rate between other classifier. In addition,
Random Forest, Decision Tree, and Naïve Bayes can classify all phishing websites as
phishing correctly. It means that TP rate is 100% for these classifiers. In conclusion this
paper suggests using NB as the best classifier for predicting phishing and non-phishing
websites.
Lightning is among the most deadly natural phenomena to mankind. This phenomenon
is seen to increase globally as well as in Malaysia. Lightning does strike open areas
such as playing fields and playgrounds and these areas are places people gather.
Sensors that can detect the early occurrence of lightning have been developed for
detecting approaching lightning activity in this project. The main objective is to provide
early lightning warning system to the public and hence to reduce the number of
fatalities due to lightning strike. The warning circuit was designed and simulated using
Multism11. Basic operational method of the circuit is based on the comparative
voltage method using LM339N integrated circuit comparator (IC). Light Emitting Diodes
(LEDs) were used as indicators to indicate if the incoming voltage level is higher or
lower than that of the safety level.
Piano technique is one of the main part of piano playing. Some researches had
attempted to unveil the technique of virtuoso pianists using technologies. These
researches employ different types of sensors in order to capture motion data of piano
playing. However, one area in this research had been under-represented, which is
finger position and pressure measurement applied by the musician while playing the
musical instrument. Research that embark on this area faced a common problem, the
sensors used in these research are directly in contact with the pianist, which causes a
change of piano playing experience. Since piano playing consists of very delicate
interaction between the pianist and the piano, such change of experience may affect
the pianist’s performance. These sensors are considered to be intrusive to the piano
playing experience. Concluding the challenges faced by current technologies, a nonintrusive
sensor is proposed and the circuit design of the sensor is discussed in this
paper.
Plywood is a wood product frequently utilized in building as part of concrete formwork systems. In the concreting process, plywood formwork needs to be strongly made to withstand the pressure subjected by the wet concrete as well as the impact. To reduce the dependency on solid timber as plywood, oil palm stem offers alternative materials. There are four main weaknesses of oil palm stem (OPS) as a material for plywood manufacturing; high variations in density and moisture content (MC), high water absorption and high surface roughness. Therefore, this study modified the drying and treatment process of OPS veneer. The veneer was predried by using roller presser for removing a large amount of water and later treated with medium molecular weight phenolformaldehyde (MMwPF) to bond together parenchyma tissue, cell wall, and a lumen for much uniform density and better surface bonding. The Charpy impact of OPS plywood developed in this study denoted as PTA was investigated. These properties were compared with the properties of another two types of commercial OPS plywood denoted as PTB and PTC which were manufactured using OPS veneer with tropical hardwood veneer for face and back veneer and control plywood denoted as PTD which was manufactured using 100% tropical hardwood veneer. The results showed that PTA has the highest mean value of energy and strength for both notched and unnotched Charpy impact.
This study aimed to integrate polyether sulfone (PES) membrane with hydroxyapatite synthesized from fish scale biowaste (HAp) to form ion exchange membrane. The PES incorporated by self-assembled with different concentrations of HAp solution; 0.2, 0.4, 0.6, 0.8 and 1.0 wt%. The prepared ion exchange membranes were characterized regarding permeability coefficient, porosity, morphology, ion exchange capacity (IEC), AT-IR, and fouling analysis. The promising characteristics and outstanding performance demonstrated by PES membrane incorporated with 0.8 wt%. Via SEM images and ATIR spectra, the PES/HAp-0.8 membrane depicted the adequate number, well distributed and low agglomeration of HAp onto the membrane surface with a strong attachment. The membrane also demonstrated good ion exchange capacity around 49%. Permeability coefficient for PES/HAp-0.8 membrane was 101.5 L/m2.h with 87.69 % membrane porosity.
The objective of this study is to characterized chitin from Leucaena leucephala pods at different aging stages with hydrochloric acid HCl by using Fourier Transform Infrared (FTIR). Leucaena leucephala is chosen to be used in this study because it is abundantly and can be found easily along the road as it is widely spread in Malaysia and available throughout the year. Leucaena leucephala is not fully utilized yet and it could potential for new source for chitin. Results from FTIR shows that Amide I band in Leucaena leucephala before and after extraction range of 1650-1600cm-1 and is not divided into two peaks which make it appear close to a β-chitin. Beside, Amide I band of Leucaena leucephala before and after extraction is appearing wide (U-shaped) rather than sharp therefore the chitin from Leucaena leucephala is determined to be in the form of β- chitin.
Microbial Fuel Cell (MFC) is a device that generates electricity from the metabolism of
bacteria simultaneously treats wastewater by decolourizing the azo dye in wastewater.
In this work, the effect of different external loads and bacterial loads were examined.
The maximum open circuit voltage generated was 390 mV by using 7 consortia of
bacteria while the maximum current generated was 50 µA using 10 Ω resistor. 97%
decolourization efficiency of 0.1 g/L of azo dye was achieved after 5 days of operation.
Besides, the maximum current density and power density achieved were 17.9 µA/cm2
and 460 µW/cm2
respectively. Polarization curve was plotted and Scanning Electron
Microscope was applied to visualize the bacterial community attachment onto the
graphite felt electrode. Cyclic voltammetry was applied to study the redox properties
of the Azo dye using microorganisms in MFC. Overall, these 7 bacterial strains used in
this work showed the capability in decolourizing the Azo dye simultaneously producing
electricity in MFC.
Kaempferia galangal rhizome is one of the traditional medicinal plant species in
Zingiberaceae family and well known as “cekur” in Borneo. Rapid emergence of
multidrug resistance of V. cholerae biofilm has increased the failure of antibiotic
treatment in recent years. This research was designed to demonstrate the
antimicrobial activity of K. galangal rhizome extract against twenty six (n=26) V. cholera
biofilm which were isolated from outbreak in Limbang, Sarawak in 2016. K. galangal
rhizome was analyzed by methanol extraction and tested against biofilm of V. cholerae.
The susceptibility of V. cholerae towards K. galangal rhizome was evaluated using disk
diffusion method which showed a maximum zone of inhibition of 12.0 mm at 1000
mg/mL concentration. As a result, the MBEC50 of V. cholerae was between 125 mg/mL
to 250 mg/mL while more than 90% biofilm eradication (MBEC90) was achieved by 500
mg/mL extract concentration. Extract-treated cell showed change in the morphology
of V. cholerae by destruction of cell wall. K. galangal rhizome extract acts as a potent
antibiofilm agent with dual actions by preventing and eradicating the biofilm of V.
cholerae.
Repetitive movement can lead to the pain muscle, nerves, and tendons that cause by
repetitive overuse of working task. The muscle will fatigue due to; repetitive
movement, force that been applied, posture during working and duration of working.
The stress level during working can influent the energy performance usage during
working. The aim of this paper is to analyse the influence of heart rate and muscle
activity of workers in composite manufacturing towards muscle fatigue. The data was
collected for a worker in hand layup department and the Qualitative method was used
in a way to investigate the working load and level of pain received by their body. Then,
the Qualitative data was sorted and the respondent proceeded for a Quantitative
method which involves muscle activity analysis and heart rate analysis. The tools that
were used to conduct these experiments were surface electromyography (sEMG),
Wristwatch with chest strap and perceived stress scale (PSS). The experimentation
used to calculate the average reading of heart rate and muscle activity during working
and detect the duration the muscle to start fatigue. Moreover, this paper analysed the
relationship between heart rate and muscle activity through the duration of working.
As an overall finding of this research, it was shown that the heart rate of the workers
influence the muscle activity of workers and has high potential relationship to the
fatigue of muscles of the workers in the layup department.