Spin coated polyvinlylidenefluoride-trifluoroetylene (PVDF-TrFE 70/30mol%) copolymer thin film were initially produced and annealed at varying temperatures (100°C to 160°C). The morphology, dielectric and ferroelectric analysis showed that PVDF-TrFE film annealed at 120°C produced the highest remnant polarization, Pr of 92 mC/m2, with orderly and grain-like shaped crystallites. The filled PVDF-TrFE, loaded with various volume percentages (1 – 7%) of Magnesium Oxide (MgO) nanofillers and then, annealed at 120°C, produced homogenous filler distribution with low agglomerates, especially for 3% PVDF-TrFE filled films. Moreover, the annealed PVDF TrFE/MgO(3%) generated the highest value of Pr in comparison to the other filled nanocomposite thin films. Most importantly, the saturation of hysteresis loop, Ps for annealed PVDF-TrFE/MgO(3%) film was relatively improved by 20% as compared to the unfilled annealed thin film. This study established that, 3% MgO loaded in PVDF-TrFE thin film and annealed at 120 °C demonstrated a stable ferroelectric thin film, closed to an ideal ferroelectric film, in which the ratio Pr/Ps for the film established a value approaching unity (value of 1).
Breast cancer is one of the most important diseases among females. According to the Malaysian Oncological Society (Wahid, 2007), about 4% of women who are 40 years old and above are suffering from breast cancer. Masses and microcalcifications are two important signs for breast cancer diagnosis on mammography. In this research, the effects of different image processing techniques which include enhancement, restoration, segmentation, and hybrid methods on phantom images were studied. Three different phantom images, which were obtained at 25kv (63.2 MAS), 28kv (29.8 MAS) and 35kv (9.5 MAS), were manipulated using image processing methods. The images were scored by two expert radiologists and the results were compared to explore any significant improvements. Meanwhile, the Wilcoxen Rank test was used to compare the quality of the manipulated images with the original one (alpha=0.05). Each image processing method was found to be effective on some particular criteria for image quality. Some methods were effective on just one criterion while some others were effective on a few criteria. The statistical test showed that there was an average improvement of 41 percent when the images were manipulated using the histogram modification methods. It could be concluded that different image processing methods have different effects on phantom images which generally improve radiologists’ visualization. The results confirm that the histogram stretching and histogram equation methods lead to higher improvement in image quality as compared to the original image (p < 0.05).
One of the issues found in small and medium industry is the poor layout design affecting its productivity
and line efficiency. In automotive industries, more attention should be given in improving assembly line
to increase productivity. This paper presents application of line balancing at the accelerator and brake
pedal assembly line at a small and medium automotive industry. Research methodology employed in
this study includes time study, visualising cycle time based on Yamazumi Chart, distribution of workload
on each workstation using line balancing based on the current takt time and re-layouting the assembly
line. All the proposed layouts are assessed using commercially available software, DELMIA Quest to
evaluate the robustness based on parameters such as fluctuation in demand, availability of the machine,
and operator capacity. Finally, the outputs presented include reduction in manpower, maximum utilisation
of manpower, as well as machine and minimum total production cost. This will lead to productivity
improvement of the assembly line.
The feasibility of an anaerobic digestion of cattle manure for biogas production is studied in this paper.
A batch thermophilic oscillatory flow anaerobic bioreactor (OFBR) operated in thermophilic (55o
C)
condition was used. Within the experimental conditions set in this study, the effect of mixing intensity on
volatile solids removal was found out to be significant. Results demonstrated that increasing the level of
mixing decreased the digester performance. Low intensity mixing at oscillatory Reynolds number (Reo)
of 100 achieved an increase of 37% in biogas yields compared to high mixing intensity, Reo of 500. It
was observed that the mixing intensity effect interacts with the methane composition in the biogas. The
benefit of decreasing mixing intensity emerges to significantly increase the methane composition in the
biogas. These experiments established that high intensity mixing was not essential for good performance
of oscillatory flow anaerobic bioreactor. In addition, the effect of mixing intensity might be reduced
through the use of a slightly lower total solid concentration, hence, lowering the operational cost of the
process. Although the study was lab scale a pilot-scale system where mixing retention times are longer
would be useful.
High strength concrete (HSC) has lower ductility, but higher in strength compared to normal strength concretes. The strength and ductility of HSC can be improved by applying external confinement, such as steel strapping tensioning technique (SSTT). However, SSTT was literately reported effective in confining circular specimens, but the effectiveness of SSTT on square cross section specimens are yet well investigated. This study focuses on HSC square cross section specimens with different corner ratio, which were right angle and rounded corner. In addition, the effect of different number of layer of steel straps confining around the specimens under optimum lateral pre-tensioning stress also been investigated. The number of layers was fixed to two layers and four layers. Fifteen HSC specimens with dimension of 88 mm x 88 mm x 200 mm, which consist of three unconfined specimens, six right angle specimens, and six rounded corner specimens were prepared and tested monotonically to failure. The experimental results show that the strength and ductility of HSC improved significantly by using rounded corner confined specimens and higher number of layer of confinements. This is due to more uniform confining pressure was exerted on entire surface of rounded corner confined specimens. The strength and ductility of the specimens can be improved up to 53.7% and 207.5% respectively.
In this paper, we proposed a new readout circuit in order to improve measurement output while reading the grouped resistive value in matrix array form. The purpose of having this circuit is to overcome the main problem in applying piezoresistive pressure sensor array for foot plantar application. This new approach is called Nodal Array Approach (NAA), a modified version of Wheatstone Bridge Circuit based on nodal analysis technique using Kirchcoff Current Law. The NAA calculates the sensors’ resistance values by solving simultaneous equations from reading voltages of the proposed readout circuit. Therefore, it is found that the readout circuit connection is of low complexity as it only uses resistive element as the major component of reading technique with only four iterations involved for each voltage nodes. Through simulation results, it shows that NAA is able to achieve high accuracy in obtaining a sensor’s resistance value by adhering to several limitations in order to avoid miscalculation (< 5% average calculation error).
Iris recognition has become a widely popular biometric system. The stable textures and features of the human iris have made such biometric systems efficient and accurate for purposes of verification and identification. The term non-ideal iris refers to a situation in which the iris is occluded by noise, including reflections, eyelashes, eyelids and so on. Most current iris recognition algorithms assume that the iris is not occluded, which is less accurate. A method using only some parts of the iris may be suitable to deal with a non-ideal iris. The current application of iris recognition systems are plagued by weaknesses such as slow processing times, especially when dealing with many irises. In this study, a sub-iris recognition technique is proposed to deal with the non-ideal iris, while reducing execution time via an embedded system using a graphical processing unit (GPU). The experiment revealed that the proposed method was accurate and fast.
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.
Positron emission tomography-computed tomography (PET-CT) is a hybrid imaging modality that plays a crucial role in detecting and managing oesophageal cancer. However, not much is known about the clinicians’ perspective on its usage for oesophageal cancer. The aim of this study is to know the perspective of clinicians on the utilisation of PET-CT imaging for oesophageal cancer patients. A total of 73 clinicians with multidisciplinary clinical specialties for oesophageal cancer management were interviewed. All these clinicians had completed a survey consisting of 31 questions on; practicality, clinical efficacy and cost-effectiveness of PET-CT. The survey used Likert-scale to evaluate the responses. In terms of PET-CT practicality and clinical efficacy 39.7% - 43.8% and 47.9% - 83.5% of the sample respectively responded positively while in with regards to cost effectiveness, there was a significant difference from being neutral to having no opinion in 6 out of 9 questions. It was clear from the study that PET-CT has positive impact in the management of oesophageal cancer patients. However, issues related to expertise, availability, staffing and bureaucracy need to be addressed to improve competency and quality of services.
Tailing sand is the residue mineral from tin extraction that contains between 94% and 99.5% silica, which can be used as moulding sand. It is found in abundance in the Kinta Valley in the state of Perak, Malaysia. Adequate water content and clay in moulding sand are important factors for better strength and
casting quality of products made from tailing sand. Samples of tailing sand were investigated according
to the American Foundrymen Society (AFS) standard. Cylindrical test pieces of Ø50 mm×50 mm in height from various sand-water ratios were compacted by applying three ramming blows of 6666g each using a Ridsdale-Dietert metric standard rammer. The specimens were tested for green compression strength using a Ridsdale-Dietert universal sand strength machine. Before the tests were conducted, moisture content of the tailing sand was measured using a moisture analyser. A mixture bonded with 8% clay possesses higher green compression strength compared to samples bonded with 4% clay. The results also show that in order to achieve maximum green compression strength, the optimum allowable moisture content for mixtures bonded with 8% clay is ranged between 3.75 and 6.5% and for mixtures bonded with 4% clay is 3-5.5%.
In this modern world, Information Technology gives impacts on society, countries, economy, and environment. This paper discusses the positive, negative, direct and indirect impacts of IT on environmental issues. A strategy for sustainable development in ICT and its future demand are also proposed. Apart from that, a research was also done to find a quantitative indicator to show the relationship between demand in IT industry and impacts to the environment. By using a mathematical formula, an estimation of the effect to the environment can be found. By using the indicator, it is hoped that society and the IT industry will become more aware of their action to the environment.
A novel nitrogen-sulphur macrocyclic Schiff base, 4,11,20,27-tetrathioxo3,12,19,28-tetrathia-5,6,9,10,21,22,25,26-octaazatricyclo[28.2.2.214,17]hexatriaconta 1(33),6,8,14(36),15,17(35),22,24,30(34),31-decaene-2,13,18,29-tetraone (TGSB) derived from terephthaloyl-bis-dithiocarbazate (TDTC) and glyoxal (ethane-1,2-dione) is synthesised via condensation. Metal complexes are formed by reacting the Schiff base with various metal salts such as Ru(III), Mo(V), Cd(II), Zn(II) and Cu(II). The complexes are expected to have a general formula of M2L or M3L with a square planar or square pyramidal geometry. These compounds were characterised by various physicochemical and spectroscopic techniques. From the data, it is concluded that the azomethine nitrogen atom and the thiolate sulphur atom from the ligand are bonded to the metal ion. In the IR spectra of the complexes, the presence of the C=N band in the region of 1600 cm-1 indicates the successful formation of the Schiff base. The structures of the Schiff base and metal complexes are confirmed via FT-IR, GC-MS and NMR spectroscopic analysis. The magnetic susceptibility measurements, electronic spectral data and molar conductivity analysis support the desired geometry of the complexes. The Schiff base and its metal complexes are evaluated for their biological activities against the invasive human bladder carcinoma cell line (EJ-28) and the minimuminvasive human bladder carcinoma cell line (RT-112). The RuTGSB and CdTGSB complexes showed selective activity against RT-112.
Controller tuning is needed to select the optimum response for the controlled process. This work presents a new tuning procedure of PID controllers with safety and response quality measures on a non-linear process model by optimization procedure, with a demonstration of two tanks in series. The model was developed to include safety constraints in the form of path constraints. The model was then solved with a new optimization solver, NLPOPT1, which uses a primal-dual interior point method with a novel non-monotone line search procedure with discretized penalty parameters. This procedure generated a grid of optimal PID tuning parameters for various switching of steadystates to be used as apredictor of PID tunings for arbitrary transitions. The interpolation of tuning parameters between the available parameters was found to be capable to produce state profiles with no violation on the safety measures, while maintaining the quality of the solution with the final set points targeted achievable.
One of the biggest power consuming devices in wireless communications system is the Power Amplifier
(PA) which amplifies signals non-linearly when operating in real-world systems. The negative effects of
PA non-linearity are energy inefficiency, amplitude and phase distortion. The increases in transmission
speed in present day communication technology introduces Memory Effects, where signal spreading
happens at the PA output, thus causing overhead in signal processing at the receiver side. PA Linearization
is therefore required to counter the non-linearity and Memory Effects. Digital Pre-distortion (DPD) is
one of the outstanding PA Linearization methods in terms of its strengths in implementation simplicity,
bandwidth, efficiency, flexibility and cost. DPD pre-distorts the input signal, using an inversed model
function of the PA. Modelling of the PA is therefore vital in DPD, where the Memory Polynomial
Method (MP) is used to model the PA with memory effects. In this paper, the MP method is improved
in Memory Polynomial using Binomial Reduction method (MPB-imag-2k). The method is simulated
using a modelled ZVE-8G Power Amplifier and sampled 4G (LTE) signals. It was found MPB-imag-2k
is capable of achieving comparable anti-scattering/anti-distortion in MP for non-linearity order of 3,
memory depth of 3 and pre-amplifier gain of 2.
This study was carried out to investigate effects of acoustic and thermofluid performance of a RanqueHilsch
Vortex Tube (RHVT) with different numbers of swirl generator nozzles. The number of nozzle
used in the experiment was 1, 2, 3, 4, 5 and 6 nozzle(s), respectively. Sound signal produced by the device
was recorded using two microphones located at hot side and cold side of the tube. The sound signal
was transformed using Fast-Fourier Transform (FFT) to obtain the frequency representation. Then, the
frequencies produced were related to its themofluid performance of each configuration.
Biocatalytic reaction is a type of reaction which uses enzyme or whole-cell as a (bio)-catalyst to achieve a desired conversion, under controlled conditions in a bioreactor. Temperature produces opposed effects on enzyme activity and stability, and is therefore a key variable in any biocatalytic processes. An exothermic biocatalytic reaction, in a continuous-stirred-tank reactor (CSTR), was analyzed where dynamic equations (non-linear differential equations) could be derived from the Michaelis-Menten and Arrhenius equations, by performing mass and energy balances on the reactor. In this work, the effects of the different parameters such as dilution rate, proportional control constant and dimensionless total enzyme concentration, on the stability of the system, were studied. The stability of the reaction could be analyzed, based on the ODE (ordinary differential equation), solved using the numerical technique in MATLAB® and the analytical investigation using Mathematica.® The numerical analysis can be carried out by considering the hase-plane behaviour and bifurcation diagrams of the dynamic equations, while the analytical analysis using Mathematica® can be undertaken by evaluating the eigenvalues of the system. In order to model the operational stability of biocatalysts, modulation factors need to be considered so that a proper design of bioreactors can be done. Temperature, as a key variable in such bioprocess systems, can be conveniently optimized through the use of appropriate models.
High Leverage Points (HLPs) are outlying observations in the X -directions. It is very imperative to detect HLPs because the computed values of various estimates are affected by their presence. It is now evident that Diagnostic Robust Generalized Potential which is based on the Minimum Volume Ellipsoid (DRGP(MVE)) is capable of detecting multiple HLPs. However, it takes very long computational running times. Another diagnostic measure which is based on Index Set Equality denoted as DRGP(ISE) is put forward with the main aim of reducing its running time. Nonetheless, it is computationally not stable and still suffers from masking and swamping effects. Hence, in this paper, we propose another version of diagnostic measure which is based on Reweighted Fast Consistent and High Breakdown (RFCH) estimators. We call this measure Diagnostic Robust Generalized Potential based on RFCH and it is denoted by DRGP(RFCH). The results of simulation study and real data indicate that our proposed method outperformed the other two methods in term of having the least computing time, highest percentage of correct detection of HLPs and smallest percentage of swamping and masking effects compared to the DRGP(MVE) and DRGP (ISE).
PM10 has been identified as being a common problem in Malaysia and many other countries all over the world. A Markov chain probability model is found to fit the average daily PM10 concentrations data of urban station (Shah Alam) and background area station (Jerantut) in Malaysia. This study aims to identify the occurrence of polluted and non-polluted days affected by PM10 concentrations based on data for 12 years’ period (2002-2013). The first order transition probability matrix of a Markov chain model and a two-state Markov chain, which are polluted days (1) and non-polluted days (0), were used for this purpose. The threshold value used in this study is referring to WHO 2006 guidelines (50µgm-3). Results of the analysis shows that there is a high probability that the next day event depends on what has happened on the previous day. The recurrence of the polluted day for Shah Alam is 4-5 days, while 2-3 days for Jerantut. By fitting the first order of Markov chain model, the results show that the higher order of Markov chain model is needed in order to get the best fitted distribution of polluted events at these two monitoring stations. Thus, the prediction of PM10 concentrations event can be made by considering the conditions of the previous day event;
Biologically inspired robotic hands have important applications in industry and biomedical robotics. The
grasping capacity of robotic hands is crucial for a robotic system. This paper presents an experimental
study on the finger force and movements of a human hand during the grasping operation in real-time.
It focuses on two topics; measuring grasping force using Flexi-force sensors and analysing human hand
action during grasping operation. The findings show that lifting required higher forces compared with
grasp force in the static phase.
Renewable energy projects in many developing countries need financial and legal back up from
governments and other supportive bodies. There is a viable alternative to finite energy via usage of
biomass waste a renewable energy source. The electrical energy production analysis on biomass waste
presented in this paper is based on the experimental analysis carried out using the laboratory and pilot
scale bioreactors. Electrical energy generated with oscillatory flow bioreactor (OFBR) was 10.12 kWh or
up to 91% higher than the 10 L lab scale bioreactor (0.9 kWh), demonstrating that the novel OFBR has a
great potential for renewable electricity. Also, the pilot scale plant achieves a value of 12.3 kWh, which
the difference is not quite significant with that of OFBR. These results illustrate that the generation of
the renewable electricity is feasible especially with the OFBR thereby achieving high methane potential
during the treatment of manure and food waste. Nevertheless, energy recoveries should be enhanced to
improve the entire operational performance.