This study deals with the fabrication of composite matrix from saw dust (SD) and recycled polyethylene terephthalate (PET) at different ratio (w/w) by flat-pressed method. The wood plastic composites (WPCs) were made with a thickness of 6 mm after mixing the saw dust and PET in a rotary type blender followed by flat press process. Physical i.e., density, moisture content (MC), water absorption (WA) and thickness swelling (TS), and mechanical properties i.e., Modulus of Elasticity (MOE) and Modulus of Rupture (MOR) were assessed as a function of mixing ratios according to the ASTM D-1037 standard. WA and TS were measured after 24 hours of immersion in water at 25, 50 and 75°C temperature. It was found that density decreased 18.3% when SD content increased from 40% to 70% into the matix. WA and TS increased when the PET content decreased in the matrix and the testing water temperature increased. MOE and MOR were reached to maximum for the fabricated composites (2008.34 and 27.08 N/mm², respectively) when the SD content were only 40%. The results indicated that the fabrication of WPCs from sawdust and PET would technically feasible; however, the use of additives like coupling agents could further enhance the properties of WPCs.

The outbreak of new coronavirus disease (COVID-19) has triggered a global panic, affecting the mental well-being of people of all ages, including students. The aim of this study was to explore the relationship between self-reported mental health concerns and subjective sleep quality of the Bangladeshi university students during the COVID-19 pandemic. A web-based cross-sectional study was conducted to maintain the social distancing recommended by the World Health Organization. There were 1,317 student responses from 49 universities across Bangladesh. Data was analyzed by executing both bi-variate and multivariate analysis. Findings indicate that 27.1%, 51.0%, 45.9%, and 86.0% of students had poor subjective sleep quality, anxiety, depression, and fear of COVID-19, respectively. Anxiety (AOR = 1.09, 95% CI: 1.06–1.12, p < 0.001) was a risk factor for increasing the poor subjective sleep quality of university students. In contrast, the odds of poor subjective sleep quality were lower with increasing the score of depression (AOR = 0.88, 95% CI: 0.86–0.90, p < 0.001) and fear of COVID-19 (AOR = 0.97, 95% CI: 0.94–0.99, p < 0.05). Compared to public university students, private university students were more likely to report poor subjective sleep quality since the pandemic began. Therefore, it is strongly recommended that psychiatric conditions of university students should be monitored during the COVID-19 epidemic, and necessary strategies, such as allocation of resources, implementation of awareness programs, establishment of psychological counselling unit, should carefully be devised.

An Approach to Using Agricultural Waste Fibres in Biocomposites Application: Thermogravimetric Analysis and Activation Energy Study