Coconut fibre reinforced composite was prepared by blending unsaturated polyester resin (UPR) from waste PET with 0.3 v% of coconut fibre. The coconut fibres were pre-treated with sodium hydroxide followed by silane prior to inclusion into the UPR. The untreated coconut fibres reinforced composite were used as a control. Dricon® as a phosphate type of flame retardant was then added to the composite to reduce the flammability of the composite. The amount of Dricon® was varied from 0 to 10 wt% of the overall mass of resin. The burning properties and limiting oxygen index (LOI) of the treated and untreated composites increased with the addition of Dricon®. The tensile strength and modulus of both composites were also increased with the addition of Dricon®. The treated fibre composite with 5 wt% Dricon® showed the highest burning time and LOI with the values of 101.5 s and 34 s, respectively. The optimum tensile strength and modulus for treated fibre composite was at 5 wt% Dricon® whereas the untreated fibre composite was at 2.5 wt% loading of Dricon®. Thermogravimetry (TGA) analysis indicated that the degradation temperature increased with the addition of Dricon® up to 5 wt% into UPR/coconut fibre composites. Morphological observations indicated better distribution of Dricon® for treated fibre composite resulted in enhancement of the tensile properties of the treated fibre composite.
Polymeric materials such as polypropylene (PP), polyethylene (PE) and ethylene propylene diene monomer (EPDM) are widely used as insulators for cable applications. We investigated the effect of alumina trihydrate (ATH) loading on the mechanical properties of PP/EPDM blend. Preliminary study showed that PP/EPDM (60:40) was the optimum composition. ATH filled PP/EPDM composites was prepared by using twin screw extruder. In this study, the tensile properties and hardness of the composites were evaluated. The tensile modulus and hardness increased while elongation at break and tensile strength decreased with increasing ATH content. Scanning electron microscope was used to study the morphology of ATH in PP/EPDM blend.
Pesakit kencing manis lebih mudah mendapat jangkitan disebabkan oleh sistem imun yang lemah. Antara jangkitan yang dialami adalah infeksi kulat kuku yang lebih dikenali sebagai onikomikosis. Satu kajian keratan rentas telah dijalankan di Pusat Perubatan Primer, Universiti Kebangsaan Malaysia untuk mengenal pasti prevalen onikomikosis dan patogen penyebab utama onikomikosis dalam kalangan pesakit kencing manis. Kajian ini dijalankan sepanjang bulan Oktober 2010 hingga bulan Mei 2011. Keratan kuku diambil dari kuku kaki yang tidak normal. Sekiranya kuku adalah normal, sampel
diambil daripada ibu jari kaki kanan. Sampel kuku diketip selepas dibersihkan dengan 70% alkohol, dimasukkan ke dalam sampul kertas dan diproses dalam masa dua jam. Sebahagian sampel diproses dengan larutan kalium hidroksida (20%) (KOH) dan sebahagian lagi dikultur pada plat media agar Sabouraud dekstros. Seramai 78 (51.7%) pesakit perempuan dan 73 (48.3%) pesakit lelaki telah menyertai kajian ini. Purata umur pesakit adalah 60.7 ± 9.1 tahun. Kebanyakan pesakit terdiri daripada etnik Melayu (60.3%, n=91), diikuti oleh Cina (24.5%, n=37), India (13.9%, n=21) dan lainlain (1.3% n=2). Prevalen jangkitan kulat kuku dalam kalangan subjek adalah 81.5%. Kebanyakan spesies kulat yang dikesan adalah kulapuk selain dermatofit (39.7%, n=60), terutamanya Aspergillus (12.6%, n=19) diikuti dengan yis (20.5%, n=31) dan dermatofit (0.7%, n=1). Keputusan kajian ini berbeza daripada kajian-kajian negara barat kerana spesies dermatofit dan yis lebih kerap ditemui. Kesimpulannya, prevalen jangkitan kulat kuku dalam kalangan pesakit kencing manis dalam kajian ini adalah tinggi. Jangkitan ini perlu dikesan dengan lebih awal dan seterusnya dirawat untuk mengelak daripada komplikasi diabetes pada kaki berlaku. Organisma penyebab utama onikomikosis dalam
kalangan pesakit kencing manis dalam kajian ini adalah kulat selain dermatofit dan ini adalah sama dalam kalangan pesakit diabetes dan populasi umum.
Oil palm empty fruit bunch (EFB) fibers were subjected to solvolytic liquefaction to convert into liquid products using ethylene glycol (EG) as a supporting agent. The process was carried out at 250˚C for 60 min. The water-insoluble product fraction was exhaustively extracted with acetone (ASL fraction) to separate all less polar. FTIR and comparative analytical pyrolysis GC/MS of the parent EFB fiber and the ASL fraction confirmed the formation of larger amounts of long-chain lipophilic compounds under liquefaction conditions. Furthermore, a considerable amount of less polar thermal lignin degradation products were obtained comprising all of the three main lignin building blocks, i.e. 4-hydroxyphenyl- (P units), 4-hydroxy-3-methoxyphenyl- (G units) and 3,5-dimethoxy-4-hydroxyphenyl (S units) substituted compounds. 4-Prop-2-en-1-yl substituted phenolic compounds contributed mostly to the cumulated peak area of all lignin derived pyrolysis products obtained by analytical Curie point pyrolysis GC/MS at 600°C. The results of both instrumental-analytical methods confirm the formation of phenol and its derivatives, furan derivatives, organic acids, hydrocarbon, ester, benzene groups and alcohols.
The dynamic shear rheometer (DSR) is one of the most complex and powerful instruments currently used to characterise the linear viscoelastic (LVE) rheological properties of bituminous binders. However, the DSR also has its limitations in that the measured complex modulus data are exposed to errors, known as compliance (testing) errors, particularly at low temperatures and/or high frequencies. This study was conducted to investigate the validity of equations developed by Schröter and associates on complex modulus data collected using the DSR. The equations used were originally developed based on the calibration of the advanced rheometric expanse system (ARES) rheometer. It was found that those equations are able to satisfactorily correct the data on unmodified bitumens and unaged bitumen-filler mastics, including unaged and aged samples. Similar results were also observed for storage and loss moduli master curves. Finally, the 2S2P1D Model was used to calibrate the corrected complex moduli data and it was found that the model satisfactorily simulates the rheological properties of tested samples.
The Bukit Lagong area is the most important aggregate supply centre in Selangor. Geological studies were carried out in four quarries in the Bukit Lagong area and samples were subjected to petrographic examination and accelerated expansion tests to assess the potential alkali-aggregate reactivity of granite aggregates. The granitic rocks comprise mainly of coarse grained megacrystic granite, minor medium grained megacrystic granite and microgranite. Petrographic examination showed that the primary minerals in these undeformed granitic rocks are not alkali reactive. Faulting and related alteration and mineralization have produced potentially alkali reactive minerals including microcrystalline and strained quartz and fine phyllosilicates. Marginally deleterious and deleterious expansion is shown by the accelerated mortar bar tests. Although alkali reactive rocks are present in some quarries in Bukit Lagong, their volume is small. When blended with the undeformed granitic rocks, the aggregates produced are not expected to cause alkali-aggregate reaction in concrete.
In this paper, a new reliable method called the step variational iteration method (SVIM) based on an adaptation of the variational iteration method (VIM) is presented to solve non–chaotic and chaotic systems. The SVIM uses the general Lagrange multipliers for constructing the correction functional for the problems. The SVIM yields a step analytical solution of the form of a rapidly convergent infinite power series with easily computable terms and obtain a good approximate solution for larger intervals. The accuracy of the presented solution obtained is in an excellent agreement with the previously published solutions.
Early treatment of orthodontic problems is important to ensure the best outcome and to avoid social stigmatization. Treatment is often prioritized based on scales such as the Index of Orthodontic Treatment Need (IOTN). Unfortunately, the conventional aesthetic component of IOTN measurement is slanted towards Caucasian malocclusions. Thus, Asian children find it particularly difficult to rate their appearance on this scale and therefore treatment may be wrongly prioritized. This study aimed to assess the use of a newly modified aesthetic scale in assessing orthodontic treatment need in adolescent. A total of 522 16-year old children were recruited. The subjects as well as the examiner rated the subject’s own dentition according to the conventional scale of aesthetic component of IOTN and the newly modified aesthetic scale. Questionnaire was given to assess the practicality of the two scales. When conventional scale was used, subjects and examiner tends to rate more to the no/slight treatment need category. However, when the newly modified scale was applied, the rating has skewed to the moderate/great need treatment category in both subjects and examiner. Moderate inter-agreement between examiner and subjects were detected when using the modified scale while poor agreement was found when using the conventional scale. Moreover, subjects found the modified scale to be easier and faster to use and more relevant to their own dentition. In conclusion, the newly modified aesthetic scale can be suggested as a better tool in assessing level of orthodontic treatment need in adolescent.
A high-order uniform Cartesian grid compact finite difference scheme for the Goursat problem is developed. The basic idea of high-order compact schemes is to find the compact approximations to the derivatives terms by differentiating centrally the governing equations. Our compact scheme will approximate the derivative terms by involving the higher terms and reducing the number of grid points. The compact finite difference scheme is given for general form of the Goursat problem in uniform domain and illustrates the performance by applying a linear problem. Numerical experiments have been conducted with the new scheme and encouraging results have been obtained. In this paper we present the compact finite difference scheme for the Goursat problem. With the aid of computational software the scheme was programmed for determining the relative errors of linear Goursat problem.
Differential cross sections for excitation to the n=2 states of atomic helium by electrons were computed for incident energies in the range from 30 to 50 eV. The n=2 states excitation cross sections are calculated with the use of closecoupling expansion with a non-orthogonal Laguerre-L2 basis function. The present status of agreement between theory and experiment for excitation of the ground-state was quite satisfactory.
Analytical probabilistic models (APM) are closed form mathematical expressions for long term system’s output performance derived from the probability distribution of the system’s input variables. In order to apply the APM for urban stormwater control systems’ design, APM parameters have to be made known. These input parameters include APM parameters which are derived from the meteorological rainfall characteristics; storm depth, duration, intensity and inter-event time. This
study is aimed to develop meteorological APM parameters that can be used for detention pond design in Peninsular Malaysia. Hourly rainfall data covering 10 to 40 years period were analyzed from 13 different locations spread across the Peninsular. The data were analyzed to obtain the APM parameters at different values of minimum storm separation time (MSST). The APM parameter of rainfall duration (λ) was found to range from a mean value of 0.260 h-1 for 2 h MSST to 0.04 h-1 for 24 h MSST. The APM parameter of rainfall volume (ζ) ranges from a mean value of 0.091 mm-1 for 2 h MSSTto 0.038 mm-1 for 24 h MSST. Similarly, the APM parameter of rainfall intensity (β) ranges from a mean value of 0.355 h/mm for 2 h MSST to 0.504 h/mm for 24 h MSST. Finally, the APM parameter of inter-event time (ψ) ranges from a mean value of 0.025 h-1 for 2 h MSST to 0.012 h-1 for 24 h MSST. Once the APM parameters are determined for a particular area, the long term stormwater control systems’ performance can easily be determined.
Fifty three samples of different types of imported and locally produced drinks consumed in the central zone of Malaysia were analyzed using gamma-ray spectrometry system equipped with a high purity germanium (HPGe) detector. The activity concentrations of the natural radionuclides 238U, 232Th and 40K present in the studied samples were measured and the radium equivalent activities Raeq were calculated. In addition, the radiation hazard index (HI) was calculated. The
average concentrations of 238U, 232Th and 40K were 0.69 ± 7×10¯4 ,1.3 ± 8×10¯4 and 20.52 ± 6×10¯4 Bq/Kg, respectively. The values of Raeq were between 0.002 and 10.0 Bq/kg. The HI were between 0.002 and 0.03, which is below one (the higher limit of HI). The results obtained were compared to the standard accepted international values and found to be within the acceptable limits.
Burkholderia pseudomallei, the causative agent of melioidosis, is an intracellular pathogen capable of invading and multiplying in both phagocytic and non-phagocytic cells. Infection results in an inflammatory response involving production of both pro- and anti-inflammatory cytokines. The cellular mechanism regulating this response, believed to play an important role in the pathogenesis of meliodoisis, is not fully understood. In recent years, glycogen synthase kinase-3 (GSK3) has been shown to assume a pivotal role in regulating production of these cytokines. Bacterial infection of host cells activates Toll-like receptors (TLRs) and results in the phosphorylation of GSK3β through activation of the phosphoinositide 3-kinase (PI3K) pathway. In this study, we investigated the effects of GSK3 inhibition in regulating B. pseudomallei-induced inflammatory response in macrophages and A549 epithelial lung cells. Our results showed that infection of cells with B. pseudomallei resulted in the increase of anti-inflammatory cytokine, IL-10 and pro-inflammatory cytokine, TNF-α. Pre-treatment of infected cells with GSK3 inhibitors caused further increase in the level of IL-10 but a significant decrease in TNF-α. These changes corresponded with the detection of phosphorylated GSK3β in infected cells treated with LiCl; suggesting that modulation of inflammatory response in B. pseudomallei infection involves phosphorylation of GSK3β (Ser 9). This could explain our observations from the invasion assays that pre-treatment of B. pseudomallei-infected cells with GSK3 inhibitors resulted in decreased intracellular replication of bacteria within macrophages and A549 epithelial lung cells. In summary, our results demonstrate a regulatory function of GSK3 in the modulation of cytokine levels during B. pseudomallei infection.
Abundant natural products with medicinal properties have been used as food and traditional medicine for diabetes mellitus all over the world. Psidium guajava fruit from the family of Myrtaceae has gained attention for its antioxidant potential. This study was conducted to determine the effects of P. guajava fruit peel aqueous extract on oxidative stress of pancreas in streptozotocin-induced (45 mg/kg) diabetic rats. Diabetic rats were administered with 400 mg/kg of aqueous extract of P. guajava fruit peel daily for 28 days duration. The results showed that diabetic rats supplemented with P. guajava extract did not cause significant difference in blood glucose level (p>0.05) as compared with diabetic rats alone. For oxidative stress evaluation, malondialdehyde (MDA) and protein carbonyl level were significantly lower and the activity of superoxide dismutase (SOD) and glutathione (GSH) level were significantly higher (p<0.05) in P. guajava supplemented rats compared with non-supplemented diabetic rats. However, histological observation showed that supplementation of P. guajava extract did not give protective effects towards alterations in pancreas histology in diabetic rats. The findings suggested that aqueous extract of P. guajava fruit peel supplementation has the ability to reduce oxidative stress in pancreas of diabetic rats and may play a role in reducing the development of diabetic complications.
Tinospora crispa and Tabernaemontana corymbosa have been used traditionally to treat fever, diabetes, rheumatism and sinusitis. The objective of this study was to evaluate the antioxidant activity of Tinospora crispa and Tabernaemontana corymbosa. The presence of apigenin and magnoflorine was detected using LCMS/MS in Tinospora crispa (Patawali) whereas appararicine, voafinine, conodusarine, conodurine, voacamine and voacangine were detected in Tabernaemontana corymbosa (Susur kelapa) methanol extract. The stem extract of Tinospora crispa showed high antioxidant activity in the following order: DPPH radical scavenging, reducing power and metal chelating assay (98.8%, 0.957, 81.97%) than Tabernaemontana corymbosa of leaves (90.04%, 0.652, 69.64%), stem (82.78%, 0.819, 36.70%) and root extracts (63.25%, 0.469, 51.56%), respectively. The high antioxidant activity in the stem extract of Tinospora crispa is due to the presence of apigenin and magnoflorine. The high antioxidant activity in Tabernaemontana corymbosa extract is due to its high phenol contents. There were significant linear positive correlation (r=0.788, p<0.001, r2=0.621) between the total phenolic content and DPPH free radical scavenging assay in the crude extracts of Tinospora crispa and Tabernaemontana corymbosa. Meanwhile, a significant moderate positive correlation was observed between the total phenolic content and ferric reducing power assay (r= 0.556, p<0.05, r2= 0.309). However, there was no significant difference in the correlation coefficient of total phenolic content and metal chelating assay.
Polymyxin B interacts with divalent cations by displacing cations from their binding sites in the lipopolysaccharide (LPS) molecules. It leads to the disorganization of the outer membrane component of the Gram negative bacteria, which releases LPS component from bacterial surface causing severe membrane leakage and finally cell death. In this paper, the reversible activity of PMB was investigated in the presence of access divalent cations such as Mg2+ or Ca2+. Membrane damage and cell disruption were monitored by detecting leakage of the outer membrane and cytoplasmic enzyme marker (β-lactamase and β-galactosidase), release of LPS component (KDO) from bacterial cells and bacterial survival. With the presence of divalent cations, leakage of enzyme markers and LPS released was significantly reduced when bacteria were exposed to PMB. The survival curve also significantly increased. The inhibitory of damage caused by PMB also depended on the type of divalent cation present. Ca2+ has been shown to be more effective in protecting the
bacteria cells than Mg2+. This is because Ca2+ appears more frequently as a constituent of the structural components of the bacteria. In conclusion, the presence of higher concentration of divalent cation particularly with Ca2+ inhibits PMB activity and maintained bacterial survival.
Protein from viscera of tuna was extracted by using water at ratio of viscera to water of 1:1 (w/v) and freeze-dried. The protein was found to be high in glycine (9.6%), arginine (9.2%), alanine (7.0%), lysine (7.2%) and leucine (7.0%). A study was then carried out to determine the effect of alcalase concentration, temperature, pH and incubation time on degree of hydrolysis (DH) during hydrolysis by using single factor experiment. The hydrolysis of viscera protein extract (VPE) was carried out at concentrations of 1.0, 1.5 and 2.0%. The DH of hydrolysates was significantly (p<0.05) increased when enzyme concentration was increased from 1.0% to 1.5% but became constant at concentration exceeding 1.5%. An enzyme concentration at 1.5% was subsequently used in the study of the effect of the other parameters. It was found that the value of the DH also increased when the temperature was increased from 30 to 40°C. However, the hydrolysis at
higher temperature (60°C) produced lower DH. Prolonging the time of incubation from 60 min up to 240 min significantly (p< 0.05) increased the DH. As for pH, there were no significant effects observed.
The critically endangered catfish eutropiichthys vacha (Hamilton 1822) is one of the commercially high nutritional valuable food fish in Asian countries, but the natural populations are seriously decreasing due to high fishing pressure, leading to an alarming condition and deserving of high conservation importance. Our study describes some biological parameters, including sex ratio, length-frequency distribution (LFD), length-weight relationships (LWRs), length-length relationships (LLRs), condition factors (Allometric, KA; Fulton’s, KF; Relative condition, KR; Relative weight, wR) and form factor (a3.0) of e. vacha in the Jamuna (Brahmaputra River distributary) River, northern Bangladesh. A total of 350 specimens ranging from 8.01-16.95 cm TL (total length) and 1.70-30.38 g BW (body weight) were analyzed in this study. Sampling was done using traditional fishing gears during March 2010 to February 2011. The overall sex ratio showed no significant differences from the expected value of 1:1 (χ2=2.57, p>0.05), and there was no significant difference in the LFD between the sexes (p=0.38). The allometric coefficient b for the LWR indicated isometric growth (~3.00) in males and combined sexes, but negative allometric growth (<3.00) in females. The results further indicated that the LLRs were highly correlated (r2>0.997; p<0.001). KR showed significant variations (F=65.11; p<0.01) between male and female; whereas, KF was not significantly different between the sexes (p=0.64). Also, wR was significantly different from 100 for both sexes (p<0.01), indicating the imbalance habitat with food availability relative to the presence of predators
for e. vacha. The estimated values of a3.0 were as 0.0060, 0.005 and 0.0054 for males, females and combined sexes of e. vacha. This study reported the first complete and comprehensive description of life-history traits for e. vacha from Bangladeshi waters. These results should be useful for the sustainable conservation of this critically endangered fishery in Bangladesh and neighboring countries.
A factorial experiment of three light intensities and three fertiliser levels was carried out on the potted seedlings of neobalanocarpus heimii as stock plants for subsequent rooting of cuttings. Light intensities used were 25%, 50% and 100% of the open sunlight and the fertilizer levels were 0 g, 1 g and 2 g plant-1 month-1. Results of 11 months after potting showed that the stock plants treated with 1 g and 2 g fertilizer had significantly better height and diameter increments than those without fertilizer in all light intensities tried. On the other hand, no significant effect of light intensity was obtained in height and diameter increments of the stock plants. Survival of stock plants of more than 86% was obtained in all light intensities tried with or without fertilizer application. Test on rooting of subsequent cuttings showed that light intensity of 25% and 0 g fertiliser, to stock plants gave the highest rooting percentage (73%) and the number of roots (2.0). The general trend showed that rooting decreased to below 60% when intensity of light was increased. In terms of size, cuttings with diameter between 1.2 mm and 2.3 mm is recommended as it yielded rooting of 65% to 75%. For practical application, a combination of 25% light intensity and 1 g of fertilizer plant-1 month-1 can be applied to the stock plants to maintain their healthy growth for continuous production of cutting materials for rooting.
The objectives of this study were to assess the intake of fluoride among 4-5 years old children from drinking water (FH20) and whether current practises of use of water filters and consumption of bottled water have any impact on fluoride intake. A questionnaire survey was conducted to elicit details of drinking water in 350 children aged 4-5 years old. The intake of fluoride from drinking water over a period of two days was biochemically determined in a subsample of 200 subjects. The majority of children (97.0%) had access to tap water, 23.1% to filtered tap water and 11.3% reported use of bottled water. The use of filters was found to be associated with ethnicity and socio-economic status (p<0.00). The mean fluoride concentration of unfiltered and filtered tap water were 0.541 ± 0.167 and 0.534±0.192 ppm, respectively. The mean volume of water consumed was 1348.76±482.70 mL/day while the mean FH2O was 726.7 ± 357.5 ug/day. The use of filters and consumption of bottled water were sparse with no significant impact on FH2O over a two-day study period.