133 research outputs found

    n-Heptane hydroconversion over nickel-loaded aluminum- and/or boron-containing BEA zeolites prepared by recrystallization of magadiite varieties

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    Phase-pure [Al]BEA and [Al,B]BEA zeolites, prepared by solid-state recrystallization of synthetic aluminum-containing magadiites and conventionally synthesized [B]BEA, were tested, after ion exchange with nickel, as bifunctional catalysts for hydroconversion of n-heptane. The reducibility of nickel ions incorporated into BEA zeolites by ion exchange was investigated by temperature-programmed reduction (TPR). The acidity of the samples was characterized with strong (pyridine (Py), ammonia (NH3)) and weak (nitrogen) bases. The adsorbed bases were studied by transmission FT-IR (Py), diffuse reflectance infrared Fourier-transform (DRIFT) spectroscopy (N2), and temperature-programmed ammonia evolution (TPAE, NH3). Over Ni/H-[B]BEA the reactants were completely converted via fast hydrogenolysis, whereas this reaction pathway plays only a negligible role in the hydroconversion over Ni/H-[Al]BEA and Ni/H-[Al,B]BEA zeolites. Boron-containing BEA zeolites were less active catalysts than the boron-free catalyst in the principal unimolecular hydroconversion reactions. However, incorporation of boron into the framework of BEA zeolite results in a considerable selectivity shift towards isomerization. Results suggest that the acid strength of bridged hydroxyls, probed with weak (N2) and strong basis (pyridine), was found to be similar in the boron-free and boron-containing BEA samples. The decrease in the isomerization rate and the increase of the apparent activation energy upon incorporation of boron may be attributed to the decrease in the heat of n-heptane adsorption

    Analytical study of radiative casson nanoliquid flow with heat absorption

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    The divergence of thermally radiative MHD flow of a Casson nanofluid over a stretching paper alongside heat absorption. The governing non linear equations are remodeled into a nonlinear ODE’s. The HAM is adopted to find the series solution. The changes of pertinent parameters are analyzed with diagrams and tables. The fluid velocity is controlled by suction and it develops with injection. The local Nusselt number rapidly suppresses with increasing the magnetic field parameter in heat generation case

    A comparative study on different BMI category and physical fitness health related component of sedentary male youth in Terengganu

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    This study aims to compare the physical fitness health related component on three different BMI category (underweight-UG; normal-NG and obese-OG) of sedentary male youth in Terengganu. 223 sedentary male youth of Terengganu (age 17.4±1.9) categorize into three groups based on BMI index value. Five physical fitness health related component (VO2max, one minute sit up and push up, V sit and reach and 20 meter speed) are measured in all groups. Multivariate Analysis of variance revealed that there is significant different between three BMI groups on physical fitness health related components F (10, 434) = 6.24, P < 0.0001. Thus, the current study shows an evidence to improve health, enhancement in each physical fitness health related components must be concentrated instead of correcting BMI alone.Keywords: BMI; physical fitness health related; obesit

    A comparative analysis of juggling skill between Sepak raga and Bulu ayam

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    The uses of sepak takraw’s ball for daily training for children might cause injury, while contact between the foot and ball due to hard and heavy structure. This study aims to examine the differences of kinematic juggling between sepak raga and bulu ayam. Eight participants within the age 13.63 (±0.52) years old were asked to perform 20 trials of sepak sila and sepak kuda juggling using raga ball and bulu ayam. Digital Motion Analysis software was used to analyze the kinematics parameters. One-way repeated measure ANOVA was implemented to examine the differences between the sepak raga and bulu ayam. The finding shows that there are no significant differences of kinematic juggling between sepak raga and bulu ayam in sepak sila juggling skills as well as sepak kuda juggling skills (p > 0.05). The young athlete could choose either raga ball or bulu ayam for skill acquisition depending on their comfort

    Association of Physical Activity with Anthropometrics Variables and Health-Related Risks in Healthy Male Smokers

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    Anthropometric variables (AV) are shown to be essential in assessing health status and to serve as markers for evaluating health-related risks in different populations. Studying the impact of physical activity (PA) on AV and its relationship with smoking is a non-trivial task from a public health perspective. In this study, a total of 107 healthy male smokers (37 ± 9.42 years) were recruited from different states in Malaysia. Standard procedures of measurement of several anthropometric indexes were carried out, and the International Physical Activity Questionnaire (IPPQ) was used to ascertain the PA levels of the participants. A principal component analysis was employed to examine the AV associated with physical activity, k-means clustering was used to group the participants with respect to the PA levels, and discriminant analysis models were utilized to determine the differential variables between the groups. A logistic regression (LR) model was further employed to ascertain the efficacy of the discriminant models in classifying the two smoking groups. Six AV out of twelve were associated with smoking behaviour. Two groups were obtained from the k-means analysis, based on the IPPQ and termed partially physically active smokers (PPAS) or physically nonactive smokers (PNAS). The PNAS were found to be at high risk of contracting cardiovascular problems, as compared with the PPAS. The PPAS cluster was characterized by a desirable AV, as well as a lower level of nicotine compared with the PNAS cluster. The LR model revealed that certain AV are vital for maintaining good health, and a partially active lifestyle could be effective in mitigating the effect of tobacco on health in healthy male smokers

    Newtonian Heating Effects of Oldroyd-B Liquid Flow with Cross-Diffusion and Second Order Slip

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    The current study highlights the Newtonian heating and second-order slip velocity with cross-diffusion effects on Oldroyd-B liquid flow. The modified Fourier heat flux is included in the energy equation system. The present problem is modeled with the physical governing system. The complexity of the governing system was reduced to a nonlinear ordinary system with the help of suitable transformations. A homotopy algorithm was used to validate the nonlinear system. This algorithm was solved via MATHEMATICA software. Their substantial aspects are further studied and reported in detail. We noticed that the influence of slip velocity order two is lower than the slip velocity order one

    Computational analysis of third-grade liquid flow with cross diffusion effects: application to entropy modeling

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    The key goal of this current study is to analyze the entropy generation with cross diffusion effects. The third-grade type non-Newtonian fluid model is used in this study. The current flow problem is modelled with stretching plate. Modified Fourier heat flux is replaced the classical heat flux. The appropriate transformation is availed to convert the basic boundary layers equations into ODEs and then verified by homotopy algorithm. The consequences of various physical quantities on temperature, velocity, entropy and concentration profile are illustrated graphically

    Design and validation of a virtual physical education and sport science–related course: A learner’s engagement approach

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    Learners’ engagement is shown to be a major predictor of learning, performance, and course completion as well as course satisfaction. It is easier to engage learners in a face-to-face teaching and learning format since the teacher can observe and interpret the learner’s facial expression and body language. However, in a virtual setting with the students sitting behind cameras, it is difficult to ascertain engagement as the students might be absent-mindedly attending the class. Henceforth, with the rapid transition to online learning, designing course content that could actively engage the students towards achieving the said elements is, therefore, necessary. We applied a data-driven approach in designing a virtual physical education and sport science–related course via a learner engagement model. A fully online course catering to 132 students that runs for a total of 14 weeks was used as a case study to develop the course. The study was conducted during the 2020/2021 academic year, which was the period of the peak COVID-19 pandemic in Malaysia. The delivery of the course content was implemented in stages to achieve three essential educational outcomes namely, skill and knowledge acquisition, and personal development as well as course satisfaction. We hypothesised that the developed learners’ engagement approach will promote the students’ acquisition of skills and knowledge and foster the personal development of the students through fitness improvement. It is also hypothesised that the students will be satisfied with the course developed upon successful completion. A chi-square analysis projected a statistically significant difference in the skill and knowledge acquisition before and after the programme (p < 0.001). A Wilcoxon rank-sum test demonstrated personal improvement in the overall fitness of the student upon completing the prescribed activity of the course content. Moreover, a total of 96.2%, 95.5% and 93.2% of students expressed their satisfaction with the clarity of the learning objectives, good organisational and course content plan, and appropriate workload of the course designed, respectively. There is sufficient evidence to accept all hypotheses formulated, and hence, we postulated that, since students spend more time outside the classroom, out-of-class learners’ engagement activity should be considered when designing a virtual course to promote lifelong learning, experience, and higher-order thinking. The techniques presented herein could be useful to academics, professionals, and other relevant stakeholders in developing virtual course content within a specific domain of interest

    Montmorillonite modified by CNx supported Pt for methanol oxidation

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    A composite support based on nature clay, i.e. montmorillonite (MMT), shows great promise as support materials for Pt electrocatalyst for the methanol oxidation reaction in fuel cell anodes. The reported composite support (CNx-MMT) was prepared via carbonizing MMT which was covered by N-contented polymer. X-ray diffraction and transmission electron microscopy results showed that Pt nanoparticles can be well-dispersed on the composite support with highly dispersed tiny crystal Pt nanoparticles. Cyclic voltammetry measurements showed that the Pt/CNx-MMT has the enhanced electrocatalytic activity in methanol oxidation reaction. The developed Pt catalyst supported on new composite support is catalytically more active for methanol electrooxidation than Pt supported on the conventional carbon support and shows good stability, offering promising potential for application of MMT as support for fuel cell electrocatalysis.Web of Scienc

    Association of physical activity with anthropometrics variables and health-related risks in healthy male smokers

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    Anthropometric variables (AV) are shown to be essential in assessing health status and to serve as markers for evaluating health-related risks in different populations. Studying the impact of physical activity (PA) on AV and its relationship with smoking is a non-trivial task from a public health perspective. In this study, a total of 107 healthy male smokers (37 ± 9.42 years) were recruited from different states in Malaysia. Standard procedures of measurement of several anthropometric indexes were carried out, and the International Physical Activity Questionnaire (IPPQ) was used to ascertain the PA levels of the participants. A principal component analysis was employed to examine the AV associated with physical activity, k-means clustering was used to group the participants with respect to the PA levels, and discriminant analysis models were utilized to determine the differential variables between the groups. A logistic regression (LR) model was further employed to ascertain the efficacy of the discriminant models in classifying the two smoking groups. Six AV out of twelve were associated with smoking behaviour. Two groups were obtained from the k-means analysis, based on the IPPQ and termed partially physically active smokers (PPAS) or physically nonactive smokers (PNAS). The PNAS were found to be at high risk of contracting cardiovascular problems, as compared with the PPAS. The PPAS cluster was characterized by a desirable AV, as well as a lower level of nicotine compared with the PNAS cluster. The LR model revealed that certain AV are vital for maintaining good health, and a partially active lifestyle could be effective in mitigating the effect of tobacco on health in healthy male smokers
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