838 research outputs found
Irrigation water quality assessment of a trans-state river basin in western part of Malaysia by integration of hydrochemical and chemometric analysis
This study aims to assess the monsoon effect on the chemical composition of water samples collected from Langat River, a trans-state river basin and to evaluate the suitability of the water for irrigation purposes. In-situ parameters (pH, salinity, electrical conductivity and total dissolved solids) and major ions (Ca, K, Mg, Na, HCO3, NO3, SO4, Cl) were determined. The water quality status for irrigation was determined based on the sodium adsorption ratio, salinity hazard, sodium percentage, magnesium hazard, residual sodium carbonate, Kelly's ratio and permeability index. Graphical presentation such as Wilcox diagram, Gibbs diagram, Schoeller diagram and Piper diagram were incorporated to display a wide range of water quality data. About 50% of the water samples collected from 30 sampling stations were beyond the good irrigation water class. The water quality at downstream was mostly unsatisfactory for irrigation purposes compared to water quality upstream, significantly proved at p<0.05. Cluster analysis revealed two different clusters of similarities between the points for both seasons, reflecting different chemical properties and irrigation water quality in the studied river
Spatial geochemical distribution and sources of heavy metals in the sediment of Langat River, western peninsular Malaysia.
The present study employed geochemical and multivariate analyses to assess the level of heavy metals (As, Cu, Cr, Ni, Pb, and Zn) in sediment along the lower reaches of the Langat River. The sediment samples were digested and analyzed for total metals by an inductively coupled plasma-mass spectrometry (ICP-MS). Selected physicochemical parameters such as pH, redox potential (Eh), electrical conductivity (EC), salinity, organic matter and cation exchange capacity (CEC) were also determined. The metal concentration from this study area was compared with interim sediment quality guidelines (ISQG). Most sediment samples did not exceed the ISQG. Geo-accumulation index (Igeo) revealed that certain sampling stations were classified as strongly polluted with respect to As and classified as moderately polluted for Pb. Based on the enrichment factor (EF) values, most sampling stations were categorized as ‘very severely enriched to extremely severely enriched for As and only 3% were moderately enriched. For Pb, pH, Eh, and CEC pose considerable influence on the composition of heavy metal in the sediment as confirmed by Pearson correlation. The hierarchical cluster analysis (HCA) revealed that sediment in the study area could be divided into two major clusters. Cluster 1 was mainly affected by the agricultural and industrial activities while Cluster 2 was heavily affected by seawater. The forensic investigation via the use of geostatistical and geochemical approaches revealed two pollution sources: (i) man-made (agricultural and industrial activities), and (ii) natural processes (seawater intrusion and geological weathering). The quantification of heavy metal concentrations thus provides a better understanding of the potential ecological risks and contamination status of the sediment. The vulnerable areas identified in this study should be given the highest priority for mitigation measures in order to alleviate pollution from industries and agriculture areas. The incorporation of source apportionment method to further understand the dynamics of environmental processes is recommended for future studies to assist in identifying possible high pollution-risk areas
Bioconcentration and translocation efficiency of metals in paddy (Oryza sativa):a case study from Alor Setar, Kedah, Malaysia
This study aimed to measure and compares the concentration of metals accumulated in various parts (grains, stems and roots) of paddy (Oryza sativa). Thirty samples were collected from selected paddy field in Alor Setar, Kedah, Malaysia. Metals (75As, 9Be, 114Cd, 59Co, 52Cr and 208Pb) concentration in various parts of the paddy and soil were analysed by using the sensitive Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). Bioconcentration factor (BCF) and translocation ratio were calculated based on the concentration of metals obtained. The mean concentration (mg/kg) of metals in grain samples were 0.06±0.12 for 75As, 0.0038±0.0037 for 9Be, 0.01±0.01 for 114Cd, 0.14±0.19 for 59Co and 0.21±0.15 for 208Pb while 52Cr concentration in all samples were below the ICP-MS detection limit. From the calculated translocation ratio, absorption of paddy had relation: root > stem >> grain. This study showed that measured concentration of metals in grain samples were all below the maximum permitted proportion (mg/kg) of Fourteenth Schedule (Regulation 38) of the Malaysian Food Regulation 1985
Comparisons of body mass index, waist circumference, waist-to-height ratio and a body shape index (ABSI) in predicting high blood pressure among Malaysian adolescents: a cross-sectional study
Objective To compare the performance of different anthropometric indices including body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR) and a body shape index to predict high blood pressure (BP) in adolescents using the 90th and 95th percentiles as two different thresholds. Design Cross-sectional study. Setting Probability proportionate to size was used to randomly select two schools in Selangor state, Malaysia. Participants A total of 513 adolescents (58.9% women and 41.1% men) aged 12–16 years were recruited. Primary and secondary outcome measures Weight, height, WC and BP of the adolescents were measured. The predictive power of anthropometric indices was analysed by sex using the receiver operating characteristic curve.
Results BMI and WHtR were the indices with higher areas under the curve (AUCs), yet the optimal cut-offs to predict high BP using the 95th percentile were higher than the threshold for overweight/obesity. Most indices showed poor sensitivity under the suggested cut-offs. In contrast, the optimal BMI and WHtR cut-offs to predict high BP using the 90th percentile were lower (men: BMI-for-age=0.79, WHtR=0.46; women: BMI-for-age=0.92, WHtR=0.45). BMI showed the highest AUC in both sexes but had poor sensitivity among women. WHtR presented good sensitivity and specificity in both sexes. Conclusions These findings suggested that WHtR might be a useful indicator for screening high blood pressure risk in the routine primary-level health services for adolescents. Future studies are warranted to involve a larger sample size to confirm these findings
Factors associated with knowledge and attitude of breastfeeding among staff of Faculty of Medicine and Health Sciences, Universiti Putra Malaysia
Introduction: Many studies have investigated the knowledge and attitude towards breastfeeding among fathers and mothers, however studies looking at working adults’ knowledge and attitude towards breastfeeding is limited. Working adults with good knowledge and favourable attitude toward the practice of breastfeeding may increase the breast-feeding initiative among working mothers. Therefore, the objective of this study was to investigate the knowledge and attitude toward breastfeeding among staff from the Faculty of Medicine and Health Sciences of a public university and its associated factors. Methods: A cross sectional study was conducted among faculty staff members. The respondents were selected by simple random sampling and a self-administered questionnaire was used to investigate the knowledge and attitude towards breastfeeding among them. Multiple linear regression was used to determine the factors associated with knowledge and attitude respectively. Results: A total of 117 respondents were recruited to take part in this study. Of these, 83(70.9%) had good knowledge while 61(52.6%) respondents had favourable attitude toward breastfeeding. There was significant positive fair correlation between knowledge and attitude score (r=0.396,p<0.001). Gender (coefficient:1.04,CI:0.25-1.84), education level (coefficient:1.56,CI:0.60-2.53) and number of children (coefficient:0.21,CI:0.01-0.40) were the factors affecting knowledge score whereas education level (coefficient:5.73,CI:1.40-10.07) and number of children (coefficient:1.3,CI:0.41-2.11) were the factors affecting attitude. Conclusion: Overall, majority of respondents were found to have good knowledge but half of them had favourable attitude toward breastfeeding. A awareness program is suggested particularly for male, low education level and those with less number of children in order to increase knowledge and attitude toward breastfeeding
Electrical conductivity studies in polycrystalline (CuSe)1-xSex
This studies are directed towards measuring the electrical conductivity of the (CuSe)1-xSex metal chalcogenide semi-conductor composites, with different stoichiometric compositions of Se (x = 0, 0.2, 0.4, 0.5, 0.6, 0.8,1.0) in bulk form. The electrical conductivity measurement was carried out at room temperature, using the parallel plate technique. The (CuSe) 1-xSex composites were prepared using solid state reaction, by varying the ratio of CuSe:Se, in the reaction mixture. The electrical conductivity of (CuSe) 1-xSex was determined to be in the range of 1.17 x 10-8 to 1.02 x 10-1 S/cm. The finding indicated that the electrical conductivity value tended to decrease as the concentration of Se increased. The effect of the concentration of Se, on electrical conductivity of (CuSe) 1-xSex composites, is discussed in this paper
Facebook Live-Streaming: How It Affect the Purchase Intention of Generation Y in Malaysia?
Today, people use social media for communicating and browsing the internet during their spare time. Additionally, people are using social media as a means of leisure during their free time. When Facebook launched its Facebook Live streaming application in 2016, the phenomenon created new opportunities for marketers. Recently, Facebook Live streaming is getting popular among companies in promoting their products and services. This research aims to investigate the factors that influence consumers’ purchase intention using Facebook Live streaming. The dependent variable of this study is the purchase intention whereas the independent variable is the attitude towards the broadcasters, interactivity, peer influence, perceived risk and product quality. There were 200 Generation Y respondents from whom information was collected via Facebook using a questionnaire. The result of the study showed that attitude and peer influence affect the consumer purchase intention when watching Facebook Live. This study gives marketers insight into improving their strategies in influencing consumer purchase intention when using Facebook Live streaming
Structural and thermal diffusivity studies of polycrystalline (CuSe)1-xSex metal chalcogenide compound
This paper reports the preparation and the characterization of the (CuSe)1−xSex metal chalcogenide semiconductor compounds with different stoichiometric compositions of Se (x = 0, 0.2, 0.4, 0.5, 0.6, 0.8, 1.0) in bulk form. The (CuSe)1−xSex compounds were prepared using the solid state reaction by varying the ratio of CuSe:Se in the reaction mixture. X‐ray powder diffraction analysis is used to identify and measure the mass absorption coefficient of the (CuSe)1−xSex compounds to support the thermal diffusivity behaviour. The thermal diffusivity of the polycrystalline (CuSe)1−xSex compounds were measured and analyzed for the first time, using the photoflash technique. The thermal diffusivity values were determined to be in the range of 2.524 × 10−3 cm 2 /s to 1.125 × 10−2 cm 2 /s. It was found that the thermal diffusivity value tends to decrease as the parameter x increases. The relationship between the thermal diffusivity, mass absorption coefficient and density of the (CuSe)1−xSex are discussed in detail
Application of geoaccumulation index and enrichment factors on the assessment of heavy metal pollution in the sediments.
An investigative study was carried out in Langat River to determine the heavy metal pollution in the sediment with 22 sampling stations selected for the collection of sediment samples. The sediment samples were digested and analyzed for extractable metal ((48)Cd, (29)Cu, (30)Zn, (33)As, (82)Pb) using the Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). Parameters, such as pH, Eh, electrical conductivity (EC), salinity, cation exchange capacity (CEC) and loss on ignition (LOI) were also determined. The assessment of heavy metal pollution was derived using the enrichment factors (EF) and geoaccumulation index (I(geo)). This study revealed that the sediment is predominantly by As > Cd > Pb > Zn > Cu. As recorded the highest EF value at 187.45 followed by Cd (100.59), Pb (20.32), Zn (12.42) and Cu (3.46). This is similar to the I(geo), which indicates that the highest level goes to As (2.2), exhibits moderately polluted. Meanwhile, Cd recorded 1.8 and Pb (0.23), which illustrates that both of these elements vary from unpolluted to moderately polluted. The Cu and Zn levels are below 0, which demonstrates background concentrations. The findings are expected to update the current status of the heavy metal pollution as well as creating awareness concerning the security of the river water as a drinking water source
Photoacoustic characterization of CuSe metal chalcogenide semiconductor using phase signal analysis
Open photoacoustic cell analysis has been done on CuSe metal chalcogenide semiconductor to obtain thermal and carrier transport properties. The thermal diffusivity, carrier diffusion coefficient, surface recombination velocity and recombination lifetime of the CuSe were determined from the photoacoustic phase signal-frequency analysis. The experimental results show that the surface recombination velocity decreases with the increasing of CuSe sample thickness. The results indicate an increasing trend of band-to-band recombination lifetime in conjunction with the increasing of sample thickness
- …