91 research outputs found

    Optical characterization on ITO/TiO2/P3HT/Areca Catechu/au for thin film hybrid solar cell

    Get PDF
    In this research, dye sensitized solar cell is fabricated by a combination of inorganic titanium dioxide nanoparticles sensitized by a locally available natural dye extract from organic Areca Catechu nut. This hybrid solar cells are fabricated accordingly by deposition of ITO/TiO2/P3HT/Areca Catechu/Au by using electrochemical method. The deposition rates of TiO2 are varied from 0.05, 0.07, 0.09 to 0.11 vs-1 whereas the number of scan of each layers are fixed to 5. The absorption spectra analysis is carried out in the wavelength range 200 to 600 nm, showed a wide and significant absorption spectrum in UV and visible regions. Analysis shows that scan rate affects the electrical conductivity of hybrid solar cell. The highest conductivity is recorded at 0.278 Scm-1 corresponding to the scan rate of 0.07 Vs-1at a potential value of 3.5 V

    Determination of iodine value of palm oil by differential scanning calorimetry

    Get PDF
    Iodine value (IV) is used as a parameter in process control as well as a quality parameter in traded palm oil products. IV measures the number of double bonds in the molecular structure of an oil. To form a double bond, carbon requires more energy (615 kJ/mol) than to form a single bond (350 kJ/mol). Therefore, the thermal behavior of an oil could reflect its iodine value. This study was conducted to demonstrate the use of a differential scanning calorimeter (DSC) to determine the IV of palm oil and its products as an attempt to reduce the use of chemicals in the analysis. The DSC thermograms of palm oil showed a clear separation of the substances that have low melting points (low-T), consisting of triunsaturated, monosaturated and disaturated triglycerides, from the high ones (high-T), consisting of trisaturated triglycerides. Regression analysis showed that the peak characteristics, namely, area and height of the low-T group and height of the high-T group in the heating thermogram and also the height of the high-T group in the cooling thermogram, can predict the IV of palm oil with R 2 higher than 0.99. This study concludes that DSC can be used to determine the IV of palm oil and its products

    The effect of the rheocast process on the microstructure and mechanical properties of Al-5.7Si-2Cu-0.3Mg alloy

    Get PDF
    This study shows the results of an experimental investigation of semisolid rheocasting of Al-5.7Si-2Cu-0.3Mg alloy using a cooling slope (CS) casting technique. However, the challenge is to determine process parameters of the CS process to get a desirable microstructure in the semisolid feedstock material. cooling slope technique was employed to create feedstock material for thixoforming under an argon gas atmosphere, where on an inclined plate that was fixed at a 60° slope angle, molten alloy is poured at different temperatures of 640°C, 650°C and 660°C at lengths 300, 400 and 500 mm. Examination the microstructure with optical microscope observed that the microstructure of conventionally cast alloy presented coarse and dendritic primary α-Al phase, whereas rheocast alloy included fine and nondendritic primary α-Al phase with homogeneous distribution of eutectic phase. The best CS processing condition has been identified for optimum pouring temperature of 650°C and the slope length of 400 mm as average globular grain size of around 31.67 ± 3 μm and a shape factor of about 0.66 ± 0.09 were obtained. The mechanical properties of conventional cast alloy were enhanced by the CS casting process. The ultimate tensile strength, the yield strength and elongation of the rheocast alloy were increased by 10%, 12% and 22% respectively compared to the conventional cast alloy. due to a reduction in shrinkage and porosity of the microstructure of the CS alloy

    Application of response surface methodology for chloride transport properties in nano metaclayed-UHPC

    Get PDF
    The major concern on the deterioration of reinforced concrete structure is due to the corrosion of steel reinforcement from the aggressive environment such as chloride penetration. Ultra-high performance concrete (UHPC) is an advanced concrete material having ultra-high strength with excellent durability properties. Inclusion of nano metaclay in UHPC is expected to overcome the chloride transport properties in UHPC by providing nano filler effect. Two (2) assessments were conducted which are chloride content and chloride depth were examined. All the concrete specimens were immersed in 3% NaCl solution up to 365 days and the tests conducted were performed at 3, 7, 28, 56, 91, 182 and 365 days. Response surface method (RSM) was performed to evaluate the interaction and relationship between operating variables (compressive strength and nano metaclay content). Based on RSM analysis, inclusion of nano metaclay in UHPC have good relationship towards the chloride resistance characteristics and adequate durability performance in terms of chloride penetration resistance. The results exhibited that inclusion of 1% nano metaclay significantly and positively affect in term of chloride penetration resistance

    Randomness test of fatty acids distribution in triacylglycerol molecules of palm oil

    Get PDF
    For food purposes, the palm oil is generally fractionated to solid (stearin) and liquid (olein) fractions. Distribution of fatty acids in triacylglycerols of palm oil determines the fate of fractionation in terms of yield and quality of the products, specifically the liquid fraction or olein. The more trisaturated and triunsaturated and the less mono- and disaturated will yield higher and better quality olein. There are six types of fatty acids found in the palm oil, but only 14 combinations are found in the triacylglycerols. In this study, such combinations were statistically tested to determine whether or not the fatty acids are randomly distributed, and if it was not, toward which direction the regulatory agent works. The distribution of fatty acids in the palm oil triacylglycerols was found to be nonrandomly distributed. Unfortunately, the palm tended to form 11.98% higher disaturated triacylglycerols, −7.4% less triunsaturated, and −4.25% less trisaturated compared to when the arrangement was random. If manipulation could be induced in such a way that the synthesis of triacylglycerols becomes random, the triunsaturated and trisaturated triacylglycerol proportion expectedly would increased to 12.57% and 12.43%, respectively. Such manipulation can be done in the plant through genetic engineering, or in the harvestedpuit through application of stimulant, or in the oil through chemical or enzymatic transesterification

    Application of Ikaz and direct quadrature for solving leakage in pipeline distribution by using transmission line modelling

    Get PDF
    A new transient-based advance towards single leak detection is proposed which requires a measurement station with an end at the pipe system. The method use the frequency response and gives adequate results using low frequency bandwidth. This research apply Empirical Mode Decomposition (EMD) as the method denoising the noisy pressure transient signal before the signal further analyze using instantaneous frequency analysis. Therefore EMD is the way to decompose into Intrinsic Mode Function (IMF) from the signal. However it is difficult to select suitable IMF. Thus the paper proposed the implementation of Integrated Kurtosis-based algorithm Z-filter technique for that allows automatic selection of relevant and appropriates IMF. This work demonstrated the synthetic pressure transient signal generates using transmission line modelling (TLM) in order to test the effectiveness of Ikaz as the autonomous selection of IMF. This paper implement the Direct Quadrature as the instantaneous frequency analysis. A straight fluid network was designed using TLM fixing with higher resistance at some point act as a leak and connecting to the pipe feature (junction, pipefitting or blockage). The analysis results using Ikaz revealed that the method can be utilized as an automatic selection of intrinsic mode function (IMF) although the noise level ratio of the signal is lower. Ikaz-kurtosis ratio is recommended and advised to be implemented as automatic selection of intrinsic mode function (IMF) through DQ analysis

    Nanofluid-cooled microchannel heat sink with carbon nanotube

    Get PDF
    Concerns over the exponential increase in the heat produced per unit area in electronic chips have driven advanced research into the nanofluid capability as a coolant. Generally reported for its improved thermal conductivity in particular at higher concentrations, different types of surfactant normally added used to stabilize the nanofluid have reported different thermal resistance to heat flow. This paper reports an analysis of the thermal performance of a nanofuid-cooled microchannel heat sink (MCHS) with 0.1% volume fraction of CNT nanofluid utilizing two different surfactants; Lignin (N2) and sodium polycarboxylate (N3) as stabilizers. Multi-objective particle swarm optimization (MOPSO) algorithm was utilized to simultaneously minimize the thermal resistance and pumping power by optimizing the design parameters; the wall width and channel aspect ratios. Optimization outcomes showed that the thermal resistance of CNT nanofluids is lower than water by 1% at 20°C. Nanofluid with N3 has a significantly higher pressure drop than water, up to 47%. CNT nanofluid with N3 performed poorly due to the high viscosity which consequently results both in higher thermal resistance and pressure drop. Since a surfactant alters the properties of nanofluid, it could improve or deteriorate the performance of a MCHS overall and must not be taken lightly as a MCHS is expected to operate for a long time

    Sensitivity and specificity of waist circumference as a single screening tool for identification of overweight and obesity among Malaysian adults

    Get PDF
    Generalised obesity and central obesity are risk factors for Type II diabetes mellitus and cardiovascular diseases. Waist circumference (WC) has been suggested as a single screening tool for identification of overweight or obese subjects in lieu of the body mass index (BMI) for weight management in public health program. Currently, the recommended waist circumference cut-off points of ≥ 94cm for men and ≥80cm for women (waist action level 1) and ≥ 102cm for men and ≥ 88cm for women (waist action level 2) used for identification of overweight and obesity are based on studies in Caucasian populations. The objective of this study was to assess the sensitivity and specificity of the recommended waist action levels, and to determine optimal WC cut-off points for identification of overweight or obesity with central fat distribution based on BMI for Malaysian adults. Data from 32,773 subjects (14,982 men and 17,791 women) aged 18 and above who participated in the Third National Health Morbidity Survey in 2006 were analysed. Sensitivity and specificity of WC at waist action level 1 were 48.3% and 97.5% for men; and 84.2% and 80.6% for women when compared to the cut-off points based on BMI ≥25kg/m 2. At waist action level 2, sensitivity and specificity were 52.4% and 98.0% for men, and 79.2% and 85.4% for women when compared with the cut-off points based on BMI (≥30 kg/m 2). Receiver operating characteristic analyses showed that the appropriate screening cut-off points for WC to identify subjects with overweight (≥25kg/m 2) was 86.0cm (sensitivity=83.6%, specificity=82.5%) for men, and 79.1cm (sensitivity=85.0%, specificity=79.5%) for women. Waist circumference cut-off points to identify obese subjects (BMI≥30 kg/m 2) was 93.2cm (sensitivity=86.5%, specificity=85.7%) for men and 85.2cm (sensitivity=77.9%, specificity=78.0%) for women. Our findings demonstrated that the current recommended waist circumference cut-off points have low sensitivity for identification of overweight and obesity in men. We suggest that these newly identified cut-off points be considered

    Biosafety of Vibrio parahaemolyticus from vegetables based on antimicrobial sensitivity and RAPD profiling

    Get PDF
    This study was undertaken to characterize the antibiotic resistance and randomly amplified polymorphic DNA (RAPD) profiles of Vibrio parahaemolyticus isolates from raw vegetable samples. A total of 46 isolates of V. parahaemolyticus recovered from raw vegetables samples and were confirmed by PCR were analyzed in this study. Most of the isolates were resistant to nalidixic acid (93.48%) and were the least resistant towards imipinem (4.35%). The MAR index results also demonstrated high individual and multiple resistances to antibiotics among the isolates. From the RAPD analysis, the size for RAPD fragments generated ranged from 250 bp to 1,500 bp, with most of the strains contained three major gene fragments of 350, 1,000 and 1,350 bp. The RAPD profiles revealed a high level of DNA sequence diversity within the isolates. Antibiotic resistance and RAPD proved to be effective tools in characterizing and differentiating the V. parahaemolyticus strain

    Redesign business model of masjid kitchens as soup kitchens, providing jobs employment and nurturing of asnaf as entrepreneurs, and income generation for the masjid

    Get PDF
    A survey conducted by the Department of Statistics Malaysia in May 2020 has found that: (a) 46.6% of self-employed respondents had reported losing their jobs; (b) an estimated 90% respondents were still working with lower than usual salaries; (c) more than two-thirds (71.4%) of self-employed respondents have sufficient financial savings for less than one month; and (d) the majority of respondents said they are unprepared if the duration of the MCO was extended except for employees under Government Linked Companies and multinational companies. In the “Families on The Edge” UNICEF report dated October 2020, COVID-19 crisis has pushed more low-income (or B40) urban Malaysian families into poverty. The poverty rate in the B40 community is higher than last year, with 50% of the families now living in absolute poverty. 70% of these households reported that COVID-19 had affected their ability to meet their basic living expenses, with 37% reporting that they struggle to purchase enough food for their families while 35% are unable to pay their bills on time. Hence, the main objectives of this paper is to offer a conceptual business model in turning masjid kitchens (or mKitchen) as a potential (a) soup kitchen for the B40 and Asnaf community, (b) job employment and nurturing of the Asnaf as entrepreneurs, and (c) income generation for the masjid via rental of kitchens. This is to turn the Asnaf community ‘Dari Penerima Zakat ke Pembayar Zakat’. The conceptual mKitchen business model can be adapted for possible implementation by masjid or mosques
    corecore