Influential predictors of students' academic achievement in online peer learning among undergraduate students

Social media is widely used by students. Previous studies have projected conflicting results regarding the influence of online peer learning via social media on academic achievement. The purpose of this study is to identify the factors that impact on academic achievement. Building on the literature, the study proposed a conceptual model consists of self-efficacy; engagement, performance expectancy, social influence, peer feedback, and collaboration were incorporated as independent variables that influence the academic achievement. Data was collected from 369 undergraduate students. The findings of regression analysis showed that the strongest predictor of academic achievement in online peer learning was performance expectancy followed by collaboration, social influence, and engagement. An online peer learning influences significantly on academic achievement. Decision makers were advised to support the implementation of online peer learning in universities

Modelling 132 kV substation for surge arrester studies

Insulation coordination models are an essential part of power system studies and are used to determine the performance of a transmission line or substation. This paper generalizes the guidelines and parameters to be used in modelling the substation and in performing the analysis on the prediction of the transformer damage. Modelling parameters and the substation layout design are based and adapted from 132/11 kV Simpang Renggam – Ayer Hitam substation in Johor Baharu, Malaysia, courtesy of the Tenaga Nasional Berhad (TNB). The model is based on the single phase line model, as was suggested by the IEEE, to be adequate to represent the substation in transient analysis simulation. Extensive analyses on the placement of the surge arresters at the substation and a prediction of the transformer damage are also presented. The results obtained from this analysis are then compared with the suggested Basic Lightning Insulation Level (BIL) by the TNB, according to the standards, for assessing the percentage of transformer damage and optimizing the substation performance in terms of its reliability and cost effectiveness

Prodigy: an Innovative Approach for Character Development

The formation and development of healthy and effective characters among the students are closely related to the role played by a counselor at school. However, in the era of globalization, the role of counselor in the development of good character in students is more difficult and complicated. Thus, apart from the knowledge and skills, counselor should have an effective strategy in encouraging the development of good character in young children. The purpose of this paper is to introduce a ‘Prodigy\u27 as an approach to assist the guidance and counseling teachers as well as other individuals who play vital roles in the development and improvement of students\u27 behavior. Prodigy is unique and innovative because it helps counselors to understand the essential elements for the improvement and enhancement of human development in schools; and comprehensive as they integrate the affective, cognitive and behavioral components of character development. This paper discusses relevant course modules for character development and touches the benefits of using Prodigy in fostering character development

Safety issues of capacitor banks in medium voltage systems

This paper describes and illustrates the important factors concerning the safety issues of capacitor banks in medium voltage (MV) power system networks. It also explains the protective issues that should be considered. A detailed account on failures and risks of capacitors during the switching operations in power distribution systems is presented. Procedures of safety, techniques of protection, existing solutions to avoid equipment damage, as well as maintaining system safety and reliability have been discussed

Substation system simulation models for transformer risk assessment analysis

This paper comprises a study which is carried out to investigate and evaluate the effect of lightning stresses on the 132 kV substation in the way to improve its reliability in the event of active lightning activities. The paper also detailed the modelling parameters of substation for this transient analysis in order to evaluate the performance and to recommend such configuration to optimize its design to be not only to withstand the stresses but to be more cost effective. The modelling and simulation are carried out using one of the most powerful power system simulations tools that is PSCAD-EMTDC and the substation layout design is adapted from 132/11 kV Simpang Renggam -- Ayer Hitam substation, courtesy of TNB. The model is based on single phase line model as it was suggested by the IEEE to be adequate to represent the substation in transient analysis simulation. The outcome of this paper would be the results of lightning stresses in term of voltage level measured at particular points in substation. The results are then compared with the suggested BIL for assessment of transformer failure

Gasification of empty fruit bunch for hydrogen rich fuel gas production

A study on gasification of Empty Fruit Bunch (EFB), a waste of the palm oil industry is investigated. The composition and particle size distribution of feedstock are determined and the thermal degradation behaviour is analysed by a thermogravimetric analysis (TGA). Then 300 g h-1 fluidized bed bench scale gasification unit is used to investigate the effect of the operating parameters on biomass gasification namely reactor temperature in the range of 700-1000°C and feedstock particle size in the range of 0.3-1.0 mm. The main gas species generated, as identified by a Gas Chromatography (GC), are H2, CO, CO2 and CH4. With temperature increasing from 700 to 1000°C, the total gas yield is enhanced greatly and has reached the maximum value (~ 92 wt. %, on the raw biomass sample basis) at 1000°C with big portions of H2 (38.02 vol.%) and CO (36.36 vol.%). Feedstock particle size shows some influence on the H2, CO and CH4 yields. The feedstock particle size of 0.3 to 0.5 mm, is found to generate a higher H2 yield (33.12 vol.%) and higher LHV of gas product (17.19 MJ m-3)

Hydrogen rich gas from oil palm biomass as a potential source of renewable energy in Malaysia

Oil palm is one of the major economic crops in many countries. Malaysia alone produces about 47% of the world's palm oil supply and can be considered as the world's largest producer and exporter of palm oil. Malaysia also generates huge quantity of oil palm biomass including oil palm trunks, oil palm fronds, empty fruit bunches (EFB), shells and fibers as waste from palm oil fruit harvest and oil extraction processing. At present there is a continuously increasing interest in the utilization of oil palm biomass as a source of clean energy. One of the major interests is hydrogen from oil palm biomass. Hydrogen from biomass is a clean and efficient energy source and is expected to take a significant role in future energy demand due to the raw material availability. This paper presents a review which focuses on different types of thermo-chemical processes for conversion of oil palm biomass to hydrogen rich gas. This paper offers a concise and up-to-date scenario of the present status of oil palm industry in contributing towards sustainable and renewable energy

Preparation and characterization of Malaysian dolomites as a tar cracking catalyst in biomass gasification process

Three types of local Malaysian dolomites were characterized to investigate their suitability for use as tar-cracking catalysts in the biomass gasification process. The dolomites were calcined to examine the effect of the calcination process on dolomite’s catalytic activity and properties. The modifications undergone by dolomites consequent to thermal treatment were investigated using various analytical methods. Thermogravimetric and differential thermal analyses indicated that the dolomites underwent two stages of decomposition during the calcination process. The X-ray diffraction and Fourier-transform infrared spectra analyses showed that thermal treatment of dolomite played a significant role in the disappearance of the CaMg(CO3)2 phase, producing the MgO-CaO form of dolomite. The scanning electron microscopy microphotographs of dolomite indicated that the morphological properties were profoundly affected by the calcination process, which led to the formation of a highly porous surface with small spherical particles. In addition, the calcination of dolomite led to the elimination of carbon dioxide and increases in the values of the specific surface area and average pore diameter, as indicated by surface area analysis. The results showed that calcined Malaysian dolomites have great potential to be applied as tar-cracking catalysts in the biomass gasification process based on their favorable physical properties

Catalytic gasification of empty fruit bunch for enhanced production of hydrogen rich fuel gas

Oil palm is widely grown in Malaysia. There has been interest in the utilization of oil palm biomass for production of environmental friendly biofuels. The gasification of empty fruit bunches (EFB), a waste of the palm oil industry, was investigated in this study to effectively and economically convert low value and highly distribution solid biomass to a uniform gaseous mixture mainly hydrogen (H2). The effects of temperature, equivalence ratio (ER) and catalyst adding on the yields and distribution of hydrogen rich gas products were also investigated. The main gas species generated, as identified by GC, were H2, CO, CO2, CH4and trace amounts of C2 H4 and C2 H6. With temperature increasing from 700 to 1000°C, the total gas yield was enhanced greatly and reached the maximum value (~ 90 wt. %) at 1000°C with a big portion of H2(38.02 vol. %) and CO (36.36 vol. %). Equivalence ratio (ER) showed a significant influence on the upgrading of hydrogen production and product distribution. The optimum ER (0.25) was found to attain a higher H2 yield (27.42 vol. %) at 850°C. The effect of adding catalysts (Malaysian dolomite1, P1), Malaysian dolomite2 (GML), NaOH, NaCl, CaO, ZnO, NiO) as a primary catalyst on gas product yield was investigated, and it was found that adding dolomite showed the greatest effect with the maximum H2 yield achieved (28.18 vol.%) at 850°C