The physical properties by natural fibre have a great importance, specifically in the structural of natural fibre which reinforces matrix. Response surface methodology with Box-Behnken (BB) design of experiment was utilized to study water absorption and melt flow index (MFI) of abaca fibre reinforced high impact polystyrene (HIPS) composites. The design utilizes fraction of weight abaca fibre, maleic anhydride (MAH), and impact modifier to develop models for characteristic behaviours of water absorption and MFI of composites. Abaca fibre reinforced high impact polystyrene (HIPS) composites were produced with different fibre loadings (30, 40, and 50 wt%), different compositions of coupling agent, maleic anhydried (MAH) (1, 2, and 3 wt%) and different compositions of impact modifier (4, 5, 6 wt%). The individual optimum of water absorption was found when loading abaca fibre close to 34.61 wt%, maleic anhydride 1 wt%, and impact modifier 4.01 wt%. The individual optimum of melt flow index dealt with loading abaca fibre 36.71 wt%, maleic anhydride 3 wt% and impact modifier 4.02 wt%. Meanwhile, the optimum condition for water absorption of abaca fibre reinforced HIPS composites was followed by a decreasing trend of the value of melt flow index.
The properties of fibre-reinforced composites are dependent not only on the strength of the reinforcementfibre but also on the distribution of fibre strength and the composition of the chemicals or additivesaddition within the composites. In this study, the tensile properties of abaca fibre reinforced high impactpolystyrene (HIPS) composites, which had been produced with the parameters of fibre loading (30,40,50wt.%), coupling agent maleic anhydride (MAH) (1,2,3 wt%) and impact modifier (4,5,6 wt.%) weremeasured. The optimum amount of MAH is 3% and the impact modifier is 6% and these give the besttensile properties. Meanwhile, Differential Scanning Calorimetry (DSC) was used to study the thermalbehaviour within the optimum conditions of the composites. In this research, glass transitions temperature(Tg) of neat HIPS occurred below the Tg of the optimum condition of composites as the temperature ofan amorphous state. The endothermic peak of the composites was in the range of 430-4350C, includingneat HIPS. It was observed that enthalpy of the abaca fibre reinforced HIPS composites yielded belowthe neat HIPS of 748.79 J/g.
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.
Cascaded multilevel inverters are popular in fields such as oil and gas, power supply installations, and
power quality devices. While there are many advantages of the cascaded multilevel inverter, its main
disadvantage is the need for large numbers of multiple dc sources. In order to reduce total harmonics
distortion (THD) of the output voltage waveform, the amount of output voltage level must be increased,
hence the higher number of dc sources. This essentially complicated the inverter design, as most converter
transform only one voltage source to another. In this paper a cascaded multilevel inverter topology with a
single dc source is discussed. The topology is based on capacitors instead of cells as the multiple voltage
sources. The cascaded multilevel inverter topology validity and functionality is verified by the Matlab
Simulink simulation of a 100W and 1kW aircraft single phase 41-level inverter.
Gallic acid (GA) is a phenolic compound found in almost all plants and has been reported to possess powerful health benefits such as anti-oxidant, anti-inflammatory, anti-cancer, and anti-diabetic properties. However, GA suffers a short half-life when administered in vivo. Recent studies have employed graphene oxide (GO), a biocompatible and cost-effective graphene derivative, as a nanocarrier for GA. However, the toxicity effect of this formulated nano-compound has not been fully studied. Thus, the present study aims to evaluate the toxicity and teratogenicity of GA loaded GO (GAGO) against zebrafish embryogenesis to further advance the development of GA as a therapeutic agent. GAGO was exposed to zebrafish embryos (n ≥ 10; 24hr post fertilization (hpf)) at different concentrations (0-500 μg/ml). The development of zebrafish was observed and recorded twice daily for four days. The toxicity of pure GO and GA was also observed at similar concentrations. Distilled water was used as control throughout the experiment. A significantly high mortality rate, delayed hatching rate and low heartbeat were recorded in embryos exposed to GO at concentrations of ≥ 150 μg/ml at 48 hr (p
Torrefaction is a thermal process to convert biomass into a coal-like material, which has better fuel characteristics than the original biomass. Torrefied biomass has more energy density and hydrophobic which is superior quality for handling and storage. The objective of this research was to develop a simulation model of the torrefied pelletization process from empty fruit bunch (EFB). The process was simulated using ASPEN Plus. Optimization involved a selection of the model option that produced the maximum mass yield and minimum energy requirement, with a converged base case simulation as a starting point. Torrefied biomass pellet offered coal-like properties such as high heating value, brittle, high bulk energy density and more hydrophobic. These properties could potentially avoid costly power plant modifications. On the other hand, Malaysia has issued National Biomass Strategy 2020 with target to solve the problem of under-utilized biomass in this country. Base model was based on previous study. For optimization of mass yield and overall energy consumption, six model options of design configurations were analysed. Design model 0 was used as the base model. For design model 1, flue gas from combustion reactor was channelled to torrefaction reactor. For design model 2, flue gas from combustion reactor was split to dryer and torrefaction reactor. For design model 3, combustion reactor was removed. For design model 4, flue gas was channelled to dryer reactor without combustion reactor. For design model 5, flue gas separator after dryer was removed. Out of five options, results were tabulated for the optimum one. The results showed that the highest mass yield was achieved by simulation Model 5 at 90.76 % and lowest energy requirement was achieved by simulation Model 4 at 411.336 kW. Optimization result meanwhile had shown that Model 4 was selected because it gave the maximum profitability of RM 72834.45 by considering the yield and the energy consumption simultaneously.
The present study aims to determine the level of heavy metals in surface soils and street dust from selected urban and peri-urban locations in the metropolitan city of Kuala Lumpur. Samples were collected from 15 different locations, where Kuala Lumpur City Centre (KLCC) served as the centre point while other locations were located at specific distances from the centre. Surface soils and street dust were collected to detect the level of contamination based on five elements (Zn, Cu, Pb, Cd and Fe). Results indicated that the metal distribution displayed a descending trend as follows: [Fe] > [Zn] > [Pb] > [Cu] > [Cd] and [Fe] > [Zn] > [Cu] > [Pb] > [Cd] in the surface soil and street dust samples, respectively. Geoaccumulation index (Igeo), contamination factor (CF) and pollution load index (PLI) were calculated. Based on the Igeo index, Fe in both samples was found to cause no pollution in all study sites. In surface soils, CF showed all sites were contaminated with Cd in both soil and street dust. In conclusion, the soil sample was polluted with metals while no pollution was found in the street dust in all sites sampled. Further intensive studies are recommended in order to determine other factors which may cause contamination.
This paper presents the outcome of a laboratory investigation on mix design, resilient modulus, moisture susceptibility and rutting resistance of Stone Mastic Asphalt (SMA) and Dense Graded Asphalt (AC) that is incorporated with Nanosilica (NS) modified binder. Penetration Grade 60-70 (PEN60-70) types of binder were mixed with nanoparticles (NS) using concentration of 0wt%, 2wt%, 4wt% and 6wt% by weight of asphalt binder. The mixtures were tested for resilient modulus, indirect tensile strength and rutting, in order to evaluate the performance of NS-SMA and NS-AC. The results show that the existence of NS is capable of enhancing the performance of both asphalt mixtures, and the addition of NS decreases the susceptibility of moisture damage and provides better resistance against permanent deformation. Furthermore, the addition of 4wt% NS appears to be the most effective amount for the performance enhancement in AC and SMA mixtures.
This paper details a study conducted to evaluate the performance of cold in-place recycling (CIPR) using polymer modified asphalt emulsion (PMAE). The asphalt emulsion was modified using natural rubber latex (NRL). Four proportions of reclaimed asphalt pavement (RAP) which are 0%, 25%, 50% and 75% were mixed with natural aggregates and modified asphalt emulsion using natural rubber latex (NRL). The results showed that the optimum modified asphalt emulsion for each proportion of RAP decreased due to the increase in RAP content. Results obtained from Indirect Tensile Strength (ITS) and Uniaxial Compressive Strength (UCS) test for the mixes complied with the requirements of the Road Engineering Association of Malaysia (REAM) specifications. The unsoaked and soaked ITS values obtained were 0.2 MPa and 0.15 MPa respectively, and the minimum compressive strength of CIPR mix obtained was 0.7 MPa. Based on the evaluation of performance for the four RAP proportions, it was determined that 50% of RAP gave the best combination of the CIPR mixture.
The new emergence and re-emergence of arbovirus infections transmitted by Aedes mosquitoes have been spreading across Southeast Asia, Central Africa, United States, tropical Oceania and has become a major of public health concern. These arbovirus diseases were found to have a similar vector, symptoms, and environments. The situation is complex due to no specific vaccine or treatments being available for the diseases. Therefore, vector control is currently the best defense against arbovirus diseases, but with its own challenges such as the difficulty in controlling scattered breeding sites and biological behavior. Herein, we present a literature review of studies on current techniques proposed to combat dengue transmission that can fill a crucial gap in vector control programs, which is the inability of conventional control methods to eliminate and destroy cryptic breeding sites. In particular, we focused on the concept of autodissemination, which is a self-delivery technique by manipulating the behavior of mosquitoes, carrying the insecticide and disseminating it to cryptic breeding sites. This technique has shown promising results in some countries and can be considered as an additional tool in a vector control program. Therefore, we conducted Boolean searches in several electronic databases including Google Scholar, PubMed, SciELO and ScienceDirect to identify relevant published data regarding dengue and autodissemination techniques.
Chronic inflammation is associated with processes that contribute to the onset or progression of cancer. This study examined the correlation between dichotomised patients with malignant tumours and inflammatory markers based on the altered glucose metabolism measured by the FDG SUVmax that underpins the degree of tumour aggressiveness. Thirty-one patients underwent 18F-FDG PET/CT for various carcinoma along with blood inflammatory markers such as C-reactive protein (CRP), interleukin-6 (IL6), lipid profile and fasting blood glucose (FBG) levels were obtained in retrospective study. Patients were dichotomised by the cut-off SUVmax value of 6.0 dl/ml derived from curve analysis (P=-0.025). The mean age of the subjects were 53.16 ± 12.06 years and mean SUVmax of 8.80±6.27 g/ml. Significant correlation was noted between the SUVmax and CRP and IL6 (r=0.361; P
The aim of this paper is to interrogate the principle of heat gain by the Overall Thermal Transfer Value
(OTTV) through residential building facades. This study proposes three façade configurations as case
studies to determine their capability of achieving the OTTV set by the current residential standards.
Utilising the OTTV formula provided by the Malaysian Standards, the OTTV of each case study was
calculated using parameters including Window-to-Wall Ratio (WWR), Shading Coefficient (SC), U-values
and solar absorption (α). Results showed that each of the façade generated OTTV exceeding the regulation
of 50 Wm-2. The study uncovered the increase in WWR leading to the increase in OTTV. The OTTV
increased alongside window areas due primarily to the high amount of heat gained through windows,
a constituent component of OTTV. Simultaneously, high Shading Coefficient (SC) and U-values were
found to cause the high amount of solar heat gained through windows. The result underpins the impacts
of high solar heat gain particularly from windows of a building envelope on OTTV. Recommendations
for improvement of OTTV of the residential façades are also discussed..
The present project investigated the potential of utilizing corncobs and sugar cane waste as viscosivier in drilling fluid. For this purpose, the synthetic-based drilling fluid, Sarapar 147, was used as the base fluid. Both the materials were subjected to pre-treatment of drying, dehumidifying, grinding and sieving process prior to rheological tests. The rheological tests were conducted in accordance with the API 13B specifications to measure mud density, plastic viscosity, yield point, 10-second and 10-minute gel strength. The study found that plastic viscosity and yield point had a direct relationship with the amount of materials added. To drill fluid additive with corn cobs, the density, plastic viscosity and yield point were increased when the amount of additives were increased. Based on these experiments, both additives were found to have the potential to be used as additive in drilling fluid. In particular, they were able to improve its rheological properties by increasing the density, plastic viscosity and yield point. The suitable concentration for the corn cobs and sugar cane is 6.45 lb/bbl and 9.43 lb/bbl, respectively.
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 work, hydrogels were prepared from carboxymethyl cellulose (CMC) and 1-vinyl-2-pyrrolidone(VP) by Electron Beam irradiation in the presence of N,N'-methylenebisacrylamide (BIS) as a crosslinkingagent. The parameters studied include stirring time and percentage of crosslinking agent. Hydrogels werecharacterized using Fourier Transform Infrared (FTIR) spectroscopy and Scanning Electron Microscopy(SEM). VP and BIS were found be effective as reinforcement materials to improve the properties ofCMC. Meanwhile, the optimum conditions were 5% BIS and 3 hours of stirring time. The gel fractionincreased when irradiation dose was increased. FTIR confirmed the crosslinking reaction between CMCand VP after the irradiation process by using BIS as the crosslinking agent. TGA thermograms showedchanges in the thermal properties of CMC-VP hydrogels in the presence of different amounts of BIS.
Crowdsourcing introduces new perspectives in innovation, allowing for new products and services to shift away from the traditional manufacture-centric model to a more user-centric one. In order for businesses to reap the benefits of open innovation, it is necessary to understand the factors that motivate ideators to contribute valuable ideas. Equally, there is an urgency to identify the challenges faced by ideators in crowdsourcing for open innovation to retain the participants of crowdsourcing communities. This paper presents a structured review to address the aforementioned issues. Our findings reveal that the intrinsic factors that drive participation in open innovation are related to the learning experience that results from sharing ideas. Extrinsic factors like social motivation are frequently mentioned in different studies. This study also highlights the need for organisations to develop strategies for interacting with their contributors in order to sustain their participation and idea contribution. In conclusion, this paper can serve as a guideline for practitioners to improve crowdsourcing platforms with the inclusion of important motivational features. It can also serve as reference for organisations for formulating policies to regulate idea contribution.
Polyaniline (PANI) and polyaniline composites with aluminium oxide (Al2O3) were prepared using the in situ polymerization method. The composites were then blended with acrylic paint and applied to carbon steel panels. The coated steel panels were evaluated for corrosion using the immersion test technique. The results revealed that the steel panels coated with polyaniline composites and with Al2O3 containing coatings had small corrosion as compared to the bare sample and the samples coated with polyaniline and paint alone. The samples were characterized by Fourier transform infrared (FTIR) and X-ray diffraction(XRD). In addition, the morphology of the finished samples was observed using the scanning electron microscopy (SEM). This novel composite was used as a paint pigment for enhancing the barrier properties and the paint protectable against aggressive ions. Meanwhile, corrosion was evaluated through visual monitoring using a digital camera after 60 days of fully immersion test in 5% NaCl. The weight loss method was also used to evaluate corrosion.
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.
This paper presents an auto grasping algorithm of a proposed robotic gripper. The purpose is to enhance the grasping mechanism of the gripper. Earlier studies have introduced various methods to enhance the grasping mechanism, but most of the works have not looked at the weight measurement method. Thus, with this algorithm, the weight of the object is calculated based on modified Wheatstone Bridge Circuit (WBC) which is controlled by programmable interface controller (PIC) method. Having this approach introduces and improves the grasping mechanism through an auto grasping algorithm. Experimental results show that an auto grasping algorithm based on pressure sensor measurements leads to a more precise grasping measurement and consequently enhance the sensitivity measurement as well as accurate movement calibration. Furthermore, several different grasping objects based on the proposed method are examined to demonstrate the performance and robustness of our approach.
Skin colour is an important visual cue for face detection, face recogmtlon, hand segmentation for gesture analysis and filtering of objectionable images. In this paper, the adaptive skin color detection model is proposed, based on two bivariate normal distribution models of the skin chromatic subspace, and on image segmentation using an automatic and adaptive multi-thresholding technique. Experimental results on images presenting a wide range of variations in lighting condition and background demonstrate the efficiency of the proposed skin-segmentation algorithm.