Universiti Putra Malaysia
Download Latest Complete Journal - JST Vol. 25 (S) Aug. 2017
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1
Full Article
(Downloads: 14)
Abstract (Viewed: 2)Sufficient knowledge on food safety and diligence during food handling are crucial to food safety and hygiene practices. A casual approach to handling food in the kitchen on a regular basis may link to foodborne pathogens, contaminations, and adverse health effects. The purpose of this study is to identify the right practices and behaviour among culinary students in terms of food hygiene practices and food safety perspectives. The methodology employed includes observations on 18 food culinary students in an actual kitchen setting. Effective food hygiene and food safety implementation are needed to improve the effectiveness of health education programmes for food handlers. The results suggest that transmission reduction of food pathogens, knowledge transfer and food safety training in selective industry criteria with proper guidelines should be introduced to produce a competent workforce.Culinary, culinary students, food safety, hygiene practices
2
Full Article
(Downloads: 5)
Abstract (Viewed: 1)This study focuses on the effect of boronizing medium on the boride layer thickness of pack boronized 304 stainless steel after surface modification. Pack boronizing treatment was conducted in temperature of 900oC for a duration of eight hours. The treatment was performed using two different boronizing mediums which are powder and paste inside a tight box in an induction furnace. The characteristics of the samples were then observed using optical microscopy and XRD analyser. The thickness of boride layer was then measured using MPS digital image analysis software. The results showed that boronizing medium significantly affected the thickness of boride layer as paste boronized samples exhibited thicker boride layer thickness. The enhancement was mainly due to the size of boron particle in the paste medium which was smaller than powder medium that enabled better diffusion. It is expected that the enhancement of the boride layer thickness would result in further improvement of the mechanical and wear properties of this material. 304 stainless steel, boron diffusion, boronizing, boride layer thickness
3
Full Article
(Downloads: 4)
Abstract (Viewed: 2)Weft density and draw in plan play an important role since they affect physical properties such as fabric weight, cloth cover factor as well as seam strength. Weft density refers to the amount of weft yarn in one inch. Meanwhile, draw in plan refers to the amount of heald shaft used and the order of warp yarn through the heald. In this study, plain woven fabrics were produced by using Sulzer Rapier Loom Machine. There were two different types of weft density used which were 15 and 20 weft per centimeter (wpcm) and four draws in plan: pointed, straight, broken and broken mirror. Seams were constructed by using plain seam of Ssa-1, four stitches of stitch density and 301 lockstitches for stitch type. Subsequently, the fabric samples were tested on seam strength by using Testometric tester. As a result of this study, it is proven that weft density and draw in plan of woven plain fabric are parameters that affect the seam strength and seam efficiency. The highest increase in percentage of seam strength was obtained from straight draw in plan which increases up to 17.19% from 15wpcm to 20wpcm. Meanwhile, broken draw in plan has the lowest increase percentage for seam strength which is 6.46%. Furthermore, seam efficiency also shows straight draw in plan gives good fabric durability compared to others. Lastly, it also shows broken draw in plan has no significant effect on fabric tensile strength and seam strength. Draw in plan, seam efficiency, seam strength, stitch density, weft density
4
Full Article
(Downloads: 7)
Abstract (Viewed: 1)A symmetrical azomethine ligand L was synthesised from a reaction of m-phenylenediamine and o-vanillin in 1:2 molar ratio. Dinuclear complexes of Zn2L2 and Co2L2 have been successfully isolated and characterised through 1H NMR, IR and magnetic moment. The x-ray crystal structure of Zn2L2 showed that the two Zn(II) nuclei were coordinated to two L moieties through the phenolic oxygen and imine nitrogen atoms, forming a slightly distorted tetrahedral geometry around the Zn(II) centres. When coordinated to metal centres, the signature n(C=N) of Lat 1616 cm-1 experienced a shift towards lower wave numbers of 1573-1613 cm-1. The Zn(II) complex was diamagnetic whereas the Co2L2 complex was paramagnetic with 3 unpaired electrons having µ eff = 4.07 B.M. An antibacterial screening against methicillin resistant Staphylococcus aureus (MRSA) revealed that the activity of the complexes was more pronounced than that of the uncoordinated L. The complex Zn2L2 revealed the lowest MIC value of 0.56 µg/µl MIC, indicating that it was a better bactericides than Co2L2 and L, in that order. Antibacterial, azomethine, binuclear, X-Ray crystallography
5
Full Article
(Downloads: 3)
Abstract (Viewed: 1)Landfill leachate imposes a huge problem to the environment and human beings. This work focused on bioconversion of leachate to acetic and butyric acids by Clostridium butyricum NCIMB 7423. A continuous stirred tank reactor (CSTR) was applied and connected to fabricate membrane module.The leachate was collected from PulauBurung Landfill Site (PBLS), NibongTebal, Penang. Prior to fermentation, leachate was treated to remove volatile fatty acid and adjusted to meet the minimum requirement of nutrients for anaerobic fermentation. Synthetic medium fermentation acts as a benchmark to the leachate fermentation. The outcomes indicated that the yield of acetic acid and butyric acid in synthetic medium fermentation was 0.70 g/L and 0.71 g/L, respectively. Meanwhile, leachate fermentation showed that the yield of acetic and butyric acid was 0.93 g/L and 1.86 g/L, respectively.High production of acetic and butyric acid showed that leachate fermentation is a green alternative to produce a cleaner product. Anaerobic, bioreactor, C. butyricum, fermentation, waste to wealth
6
Full Article
(Downloads: 2)
Abstract (Viewed: 1)Oxidation of low-density lipoprotein (LDL) and activation of the transcription factor nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) are critical for the inflammatory response for endothelial dysfunction. The objective of this study is to investigate the effects of various doses of HDL on: (a) LDL susceptibility to oxidation; (b) expression of eNOS; and (c) expression of NF-κB p50 and p65. Different concentrations of HDL were incubated in LDL. The reaction rates of LDL susceptibility to oxidation were obtained by kinetic modeling analysis. For determination of eNOS, NF-κB p50 and p65 expression, different HDL concentrations were incubated in lipopolysacharides (LPS)-stimulated human umbilical vein endothelial cell line for 16 hours. Protein was extracted and analysed by western blot and nuclear transcription factor, for example, Co-incubation of LDL with increasing HDL concentrations showed longer lag time and lower reaction rate in a dose-dependent manner compared to controls (p<0.05). The eNOS expression at higher HDL concentration was significantly increased when compared to controls (p<0.05). HDL significantly decreased the expression of NF-κB p65 but not that of NF-κB p50. HDL protects LDL from oxidation, up regulates eNOS expression and down regulates the expression of NF-κB p65. These in part contribute to the role of HDL in the prevention and retardation of atherogenesis and atherosclerosis-related complications. eNOS, NF-κB, endothelial cells, HDL, LDL oxidation, protein expression
7
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(Downloads: 3)
Abstract (Viewed: 1)Chronic inflammation plays a pivotal role in atherogenesis. Antioxidants have a potential role in the prevention and treatment of atherosclerosis. The effects of palm oil-derived tocotrienol-rich fraction (TRF) supplementation on inflammation are not well established. This study aims to investigate the effects of TRF supplementation on the inflammatory biomarkers and adhesion molecules in severe atherosclerosis. A total of 28 New Zealand white rabbits were given 1% high-cholesterol diet (HCD) for five months and randomised from the second month onwards into one of five intervention groups: Placebo, TRF 15, 30, 60 and 90 mg/kg/day. Treatment was given for three months and the animals were fed HCD throughout the duration. At the end of the study, the aortas were obtained, stained with Sudan IV, fixed in formalin, embedded in paraffin and immunostained for tissue intracellular adhesion molecule-1 (ICAM-1), interleukin-6 (IL-6), E-selectin, smooth muscle actin (SMA), and nuclear factor-κB (NF-κB). The amount of atherosclerotic lesions was not significantly different between the groups and compared to placebo. Qualitative analysis showed lower trend of ICAM-1, IL-6, E-selectin and NF-κB but higher trend of SMA tissue expression in TRF-treated groups especially at low dose of TRF (TRF-15) compared to placebo. Quantitative analysis showed lower ICAM-1 and E-select in positivity in TRF-15 compared to placebo group (25.1 ± 7.4 % vs. 3.8 ± 2.0 %, 23.2 ±6.5 % vs. 4.2± 2.1 %, respectively, p<0.05). In conclusion, low dose TRF is potentially beneficial in attenuating vascular endothelial activation in severe atherosclerosis. Aorta, atherosclerosis, inflammation, tocotrienol-rich fraction
8
Full Article
(Downloads: 3)
Abstract (Viewed: 1)Tocotrienols have been reported to possess potent cholesterol lowering, anti-hypertensive, anti-inflammatory and anti-oxidative properties which are superior to tocopherols. Emerging evidence suggests pure tocotrienols have anti-atherogenic properties. However, optimal doses of oftocotrienol-rich fraction (TRF) in progressive atherogenesis remain unclear. This animal model experiment was designed to investigate the effects of a range concentration of TRF supplementation on the extent of atherosclerosis and soluble lipids, inflammatory and oxidative stress biomarkers in high-cholesterol diet (HCD) induced hypercholesterolaemic (HC) rabbits with atherosclerosis. A total of 28 New Zealand white rabbits were given 1% high-cholesterol diet (HCD) for two months and then randomised into five groups: Placebo (n=7), TRF 15 mg/kg (n=5), TRF 30 mg/kg (n=6), TRF 60 mg/kg (n=5) and TRF 90 mg/kg (n=5) daily. The treatment was given for three months and the animals were fed HCD throughout the duration. Aortic vessels were obtained to assess the extent of atherosclerotic lesions at the end of the study. Fasting serum lipids (FSL), C-reactive protein (CRP), malondialdehyde (MDA) and 8-isoprostane levels were measured at baseline, one and two months post-HCD, one, two, and three months post-intervention. There were no differences in the extent of the atherosclerotic lesions, percentage changes of FSL, MDA, 8-isoprostane and CRP levels between the placebo and TRF groups. In conclusion, TRF across all doses studied have neutral effects on atherosclerotic lesions, soluble lipids, biomarkers of oxidative stress, coronary risk and inflammation in severely atherosclerotic rabbits with progressive and continuous insult by high cholesterol feeding. Atherosclerosis, inflammation, lipids, oxidative stress, soluble biomarkers, tocotrienol-rich fraction
9
Full Article
(Downloads: 5)
Abstract (Viewed: 1)The increasing demand for high-strength light-weight fibre reinforced polymer (FRP) composite materials has driven the researchers to further innovate and introduce hybrid reinforcement materials. The usage of hybrid FRP composite and metal foam in the fabrication of sandwich panel in structural industries is still new and limited research has been reported in this area. In addition, there is limited research data on aluminium foam as a core material in sandwich panel and needs to be further studied. This research is aimed to determine the bending properties of closed-cell aluminium foam sandwich panel with hybrid FRP composite face-sheets. The three-point bending tests were carried out in order to determine mechanical properties of the material, such as Young's modulus and strength. The sandwich panels were prepared using FRP composite face-sheets, which consist of carbon and glass fibres and epoxy matrix, and closed-cell aluminium foam core material. The results show that aluminium foam sandwich panel with hybrid FRP composite face-sheets exhibit higher flexural strength and modulus compared to the neat closed-cell aluminium foam panel. It also has higher flexural strength and flexural modulus, by 338% and 136% respectively, as compared to the aluminium honeycomb sandwich panel. Aluminium foam, aluminium honeycomb, flexural strength, flexural modulus, hybrid FRP composite
10
Full Article
(Downloads: 2)
Abstract (Viewed: 1)In this study, oil palm fruit bunch fiber (OPEFB) was used as a secondary filler in HDPE/clay nanocomposites. The composites were prepared by melt compounding, containing high density polyethylene (HDPE), OPEFB fibers, Maleic anhydride grafted polyethylene (MAPE) and four different clay loading (3, 5, 7 and 10 PE nanoclaymasterbatch pellets per hundred HDPE pellets). Four OPEFB sizes (180 µm, 250 µm, 300 µm and 355 µm) were added in the composites to investigate its effects on the fracture toughness and impact strength. Fracture toughness of the composites was determined according to ASTM D5045 and single edge notch bending (SENB) was employed during the test while impact tests were performed according to ASTM D256. The effects of alkali treatment were also investigated in this study. The result indicates that the fracture toughness slightly increased as clay loading increased. The highest value of fracture toughness was 0.47 and 1.06 MPa.m1/2 at 5 phr for both types of composites. The presence of OPEFB fiber as a secondary filler in the matrix indicates significant enhancement of fracture toughness up to 133%. However, its impact strength seems to deteriorate with the presence of OPEFB fiber. Alkali treated, hybrid nanocomposite, oil palm empty fruit bunch (OPEFB) fiber, polyethylene, polymer
11
Full Article
(Downloads: 7)
Abstract (Viewed: 2)This study focuses on examining the influence of post weld impact treatment (PWIT) using Pneumatic Impact Treatment (PIT) for spot welded joint on mechanical properties and fatigue failure. PWIT is one of the methods for improving mechanical properties and fatigue strength of welded joints. One of the versatile techniques of PWIT used for this study is PIT. The material investigated in this study was carbon steel with welded single lap shear joint with the constant thickness of 1.2mm. All the welded samples were later performing the tensile shear test, hardness test, and fatigue test. The tensile shear test was conducted on the spot welded both treated and untreated samples using crosshead speed of 2 mm/min, while hardness test was performed using 1kgf load via Vickers hardness indenter. Fatigue test was conducted using R=0.1 and frequency of 10 Hz. The effects of PIT on tensile-shear properties, hardness, and fatigue failure were evaluated. It was found that the implementation of PIT has increased tensile shear and hardness significantly and prolonged lifetime of spot welded joint. Fatigue failure, pneumatic impact treatment (PIT), post weld impact treatment, resistance spot weld, spot-welded
12
Full Article
(Downloads: 3)
Abstract (Viewed: 3)Post Weld Impact Treatment (PWIT) is necessary in order to improve the tensile shear and hardness strengths on the welded joints of spot welding process. PWIT can be performed via Low Blow Impact Treatment (LBIT), which is the main focus in this research. In this present study, two plates of low carbon steel (LCS) with dimensions of 110 mm × 45 mm × 1.2 mm underwent a resistance spot welding. All welded samples were later tested for their mechanical properties by performing the tensile-shear, hardness test and qualitative analysis. Tensile shear test was conducted on the spot welded area for both treated and untreated samples using crosshead speed of 2 mm/min, while hardness test was performed using 1 kgf load Vickers hardness indenter. The effects of LBIT on tensile-shear properties, hardness and fatigue strength were evaluated and it was found that the implementation of LBIT increased the tensile shear strength, fatigue strength and hardness on the welded joint significantly. Hardness test, LBIT, LCS, PWIT, tensile-shear test
13
Full Article
(Downloads: 3)
Abstract (Viewed: 1)High uncertainties in aerosol radiative forcing (ARF) arise from inaccurate estimation for aerosol optical depth (AOD) as an input parameter into Santa Barbara Discrete Ordinate Radiative Transfer (SBDART) model. Influence of AOD in ARF at the top of atmosphere (TOA) and surface over Kuching from 2011 until 2015 was investigated using Moderate Resolution Imaging Spectroradiometer (MODIS). Multi plane regression technique was used to retrieve AOD from MODIS (AODMODIS) by using different statistics (mean and standard deviation (MODISµ±s) and relative absolute error (MODISRAE) for accuracy assessment in spatial averaging and compared with Aerosol Robotic Network (AERONET). The relationship between AODMODIS and AOD from AERONET (AODAERONET) showed R2 value for MODISµ±s and MODISRAE is 0.906 and 0.932, respectively. AODMODIS over Kuching tends to underestimate AOD during low variations and overestimate AOD when aerosol loading is higher. The retrieval of AODMODIS was used as an input parameter into SBDART for ARF estimation and compared with ARF from AERONET. When using AODMODIS from MODISµ±s, the ARF at TOA was between -5.95 Wm-2 and 0.89 Wm-2 and at the surface was from -389.7 Wm-2 and -31.4 Wm-2 while for MODISRAE, ARF value at the surface was from -392.3 Wm-2 and -27.3 Wm-2 while at TOA was between -5.89 Wm-2 and 0.98 Wm-2. Average ARF value within the atmosphere for both MODISµ±s and MODISRAE were 151.6 Wm-2 and 130.4 Wm-2, respectively. There is a poor relationship between the SBDART and AERONET for MODISµ±s, where R2 is 0.33, while strong relationship is observed for MODISRAE with R2 value at 0.724. Aerosol optical depth, aerosol radiative forcing, AERONET, MODIS
14
Full Article
(Downloads: 22)
Abstract (Viewed: 4)A full description of a new reading chart in Malay language, the Buari-Chen Malay Reading Chart (BCMRC) is described. Internal and external comparisons of BCMRC are also reported. BCMRC comprised four reading sets with contextual sentence (CS1 and CS2) and random words (RW1 and RW2) designs. A total of 14 prints, ranging from 1.3LogMAR to 0.0LogMAR in 0.1LogMAR steps (equivalent to 8 M to 0.4 M) were printed in high contrast Arial font. CS1, CS2, RW1 and RW2 were presented in random order to the participants for internal comparison. The reading was evaluated aloud with clear pronunciation (errors were recorded). Maximum reading speed (MRS) was reported in words per minute. The external comparison involved two standard English reading charts [MNread acuity chart (MNread) and Bailey-Lovie words reading chart (Bailey-Lovie)]. The internal and external comparisons were analysed using the intra-class correlation coefficient (ICC) and Cronbach's alpha (a) respectively. Contextual sentence set (ICC=0.82) and random word set (ICC=0.85) exhibited good reliability in our internal comparison. The external comparison showed acceptable reliability for both MNread (a=0.76) and Bailey-Lovie (a=0.80). BCMRC sets with similar features could be used interchangeably to monitor clinical progress in visual rehabilitation. BCMRC was comparable with MNread and Bailey-Lovie reading charts. Malay reading chart, reading, reading chart, reading speed
15
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(Downloads: 5)
Abstract (Viewed: 1)This article aims to quantify the colour discrimination ability by using Total error scores (TES) to categorisecolour discrimination level into superior, average or inferior levels under three different types of light sources, with different spectral power distribution. Colour discrimination was investigated using Farnsworth-Munsell 100 hues and compared upon three light sources: compact fluorescent light (CFL), fluorescent light (FL) and light emitting diode (LED). Total error score calculated and pattern of colour caps misplacement plotted used the web-based scoring method (http://www.torok.info/colorvision/fm100.htm). Total error score (TES) for three types of light sources (TES for LED 58.00 ± 18.67, FL 80.00 ± 19.27 and CFL 127.25 ± 28.02) were significantly different [One-way ANOVA (F=9.98, P<0.05)]. Tukey post hoc analysis showed that there was significant difference between compact fluorescent light & fluorescent light, and between compact fluorescent light & light emitting diodes. Variation of the mid-point cap was smaller for both types of fluorescent lights but higher under light emitting diodes. Fluorescent light and light emitting diode with 4000K correlated colour temperature showed average colour discrimination with mean total error score range between 20 to 100, while compact fluorescent light showed inferior colour discrimination with mean total error score of more than 100. Different light sources with different spectral power distributions affected the colour discrimination differently. This cross-over study design using the same subjects, the same testing tool and the same examiner suggested that subject responded differently towards fluorescent light and light emitting diode light source in the total error score of the Farnsworth-Munsell 100 hues. Colour discrimination, Farnsworth-Munsell 100 hues, fluorescent, light emitting diode, light source
16
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(Downloads: 4)
Abstract (Viewed: 2)The purpose of this study was to develop a simple, economical but efficient procedure to collect illuminance data in quantifying interior lighting. This study was carried out in 3.8 m × 2.9 m × 3.0 m controlled experimental room. Three approaches to measure illuminance level were examined: (1) row-to-row; (2) column-to-column; and (3) zig-zag direction. A pre-determined 34 measurement points was used for all the three approaches. The duration required to complete the illuminance data measurement was recorded in minutes. There was a statistically significant difference in the total time measured to complete the illuminance data measurement in three different approaches (F(2, 4) = 23266.81, p<0.05). The finding concluded that the zig-zag direction approach was the fastest and most efficient way in quantifying interior lighting. Illuminance, interior lighting, lux meter, lighting quantification, zig-zag pattern
17
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(Downloads: 6)
Abstract (Viewed: 1)This study was conducted to investigate mitochondrial, nuclear chromatin and cytoskeletal organisation of vitrified embryos based on timing of the first zygotic cleavage. Embryos were retrieved from superovulated ICR mice, 28 hours after hCG injection. Two-cell stage embryos were categorised as early-cleaving (EC), while zygotes with 2-pronuclei as late-cleaving (LC) embryos. Embryos were cultured overnight in M16 medium supplemented with 3% bovine serum albumin (BSA) in carbon dioxide incubator. After 20 hours, the embryos were vitrified for one hour and warmed to room temperature. They were then fixed and immunostained to visualise distribution and intensity of mitochondria, nuclear chromatin and cytoskeleton. Finally, the embryos were mounted on glass slides and examined under a Confocal Laser Scanning Microscope (CLSM). Fluorescence intensities were analysed using LAS-AF-Lite Software. Results showed that EC embryos had significantly higher mitochondria (39.22 ± 12.50 versus 35.42 ± 14.61 pixel, p<0.05) and actin filaments fluorescence intensities (11.43 ± 5.44 versus 5.23 ± 2.20 pixel) compared to LC embryos (p<0.001). There was no significant difference in nuclear chromatin and microtubules fluorescence intensities between EC and LC embryos. These findings suggest that greater cryosurvivability of vitrified EC compared to LC embryos was contributed by higher densities of mitochondria and actin filaments. Thus, selection of embryos for IVF procedure should be made based on timing of the first zygotic cleavage. Actins, chromatin, cytoskeleton, early cleavage, embryo, microtubules, mitochondria, vitrification
18
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(Downloads: 4)
Abstract (Viewed: 2)Cryopreservation by vitrification has been widely used in Assisted Reproductive Technology (ART) to preserve embryos for an extended period of time. However, the effect of vitrification on development of the embryos is lacking. Therefore, understanding on vitrification effects on embryonic proteins, especially those involved in preimplantation development is crucial to provide high quality embryos for further usage. In this study, XIAP and S6K1 protein expressions following vitrification was investigated, since they have been implicated in diverse cellular processes including cell growth, migration, proliferation, differentiation, survival and development of preimplantation embryos via the PI3K pathway. Embryos were obtained from superovulated female ICR mice which were mated with fertile males. The embryos were harvested at the 2-cell stage and cultured until blastocyst stage. Blastocysts were then vitrified in ESF40 cryoprotectant. Western blot was carried out to determine the expression of XIAP and S6K1 proteins. The results showed the expression of XIAP and S6K1 significantly decreased in vitrified blastocyst compared to the control. This indicates that blastocyst vitrification may impact developmental competence through the activation of apoptotic pathways. Blastocyst, cryopreservation, embryo, PI3K, vitrification
19
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(Downloads: 4)
Abstract (Viewed: 2)Kenaffibre is one of the natural fibers that has received much attention of many researchers because of its good properties and flexible use. Kenaffibre composites have been proposed as interior building materials. In this study, the recycling effect on the kenaf PVC wall panel is focused. The main objective of this study is to determine the mechanical properties of different types of kenaf PVC wall panels. The samples were formulated based on the first and third recycling process. The specimens were subjected to several types of tests, namely, tensile, izod impact, flexural and hardness based on ASTM D3039, ASTM D256, ASTM D7264 and ASTM D785, respectively. The results indicate that the mechanical properties of the third recycled kenaf PVC wall panel product is better than the virgin and first recycled specimen. This shows that the recycling process enhances the mechanical properties of the product. On the other hand, the hardness of the specimen decreases after first recycling due to the reheating effect. Kenaf fiber, kenaf PVC wall panel, mechanical properties, recycling

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