The management of role stress is becoming more dominant issue in the career life of teachers due to various roles that teachers need to play in their job. Among the factors of role stress are role conflicts, role ambiguity and role overload. The main purpose of this research is to study the influence of selected factors such as role conflict factor, role ambiguity and role overload on role stress among the Malaysian National Primary School teachers. This study was designed by utilizing the quantitative approach. The instrument used was a questionnaire which has been adapted from various relevant researchers. A total of 150 teachers were randomly selected as respondents and the data obtained were analysed using SPSS for descriptive statistics and Smart PLS for the inferential statistics. The findings show that the level of stress was at moderate level. In addition, the findings indicate that there is a significant relationship between role conflicts (ß=0.212, t=2.640, P=0.009), role ambiguity (ß=0.219, t=2.701, P=0.007) and role overload (ß=0.372, t=4.364, P=0.000) to role stress. As a conclusion, this study demonstrates that role conflicts, role ambiguity and role overload have a major impact to the role stress of teachers in Malaysia. It is hoped that through this study, various stakeholders such as schools, the district education offices as well as the Ministry of Education will be able to assist in planning and organizing efforts to address the role stress issues in order to produce highly qualified teachers.

Depletion of fossil fuels, concerns on environment, and fuel price fluctuation have become the major drives in searching for sustainable alternative fuel. In that regard, a study was conducted to evaluate the combustion performance of Waste Cooking Oil (WCO) converted into biodiesel and blended with Conventional Diesel Fuel (CDF) as a mean of sustainable replacement for diesel fuel. In this study, the production of biodiesel fuel from waste cooking oil was done via transesterification process, using the single step approach. The properties of the WCO biodiesel was characterized. The combustion performance of the produced fuels has been studied for B10 and B30 biodiesel from WCO and CDF (as baseline) based on their wall temperature profiles and gaseous emissions generated such as nitrogen oxides (NOx), carbon monoxide (CO) and sulphur dioxide (SO2). It was found that the B30 WCO biodiesel emits lower emission compared to CDF but at the same time generates a lower temperature profile.