Occupational Health and Safety Assessment of the Industries in Bhutan: A Three Years’ Trend Analysis

Introduction: Workplace plays an important role in the lives of not only workers but also their dependents and families. Therefore, it is very important to consider safety and health in every workplace. However, the health and safety standards in Bhutan is still at a premature stage.Objective: The objective of this study is to assess the overall occupational health and safety situation in the country to better understand the level of occupational safety and health standards in the country.Methods: All the enterprises in Bhutan, who had constituted a health and safety committee in 2016 to 2017 were considered. Structured questioners were used for assessing and evaluating the health and safety standards at the workplace.Results: The study found that the health and safety standards have improved however, improved marginally with the higher percentage of improvement falling in the fair practice of health and safety at their workplace.Conclusion: The Department of Labour plays a pivotal role in taking leadership and educating employers, employees, the general public on workplace safety and health. Therefore, it is important for the Department to rigorously enforce the safety and health standards in the companies. Further, the management of the companies also needs to ensure commitment and leadership for implementation of workplace safety and health

The relationship between estimation skill and computational ability of students in years 5, 7 and 9 for whole and rational numbers

This study explored the relationship between estimation skill and computational ability for whole and rational numbers. The methods carried out were both quantitative as well as qualitative and data were collected from three primary schools along with their associated high school in the Perth area. The year levels chosen were 5, 7 and 9. There were two classes from each chosen primary school representing Year 5 and Year 7 and three classes of Year 9 from the high school. The total number of students involved was 91, 77 and 73 from the three respective year levels. Instruments used for collecting data were group-administered tests and interview. Two parallel tests with identical items, where one of the pair was estimation and the other written computation were administered to all the students in the chosen year levels. Interviews were conducted for the group of selected students based on the criteria: slightly above the average and slightly below the average. There were eighteen students with nine in each group. The results of the correlation shows that performance in estimation is positively correlated with written computation in all the year levels. Moreover, the t-test result reveals that there is no significant difference between the two tests expect in Year 7. Hence, the findings indicate that a child who is good in estimation skill can also perform well in written computation. As such, the importance of achieving estimation skill in a child would be very helpful in solving computation problems with understanding. On the other hand, children\u27s performance related to the development of estimation skill and computational ability seems to be in positive direction from Year 5 to Year 7. Whereas the Year 9\u27s performance is lower than Year 7. Among the topics, the children fared better in whole numbers compared to other topics. Performance tends to follow in a descending order from whole number to ratios. The disparities between estimation skill and computational ability are also more towards the difficult topics like division and multiplication of fractions and decimals. At the same time, the feedback from the interviewees tend to show that, the children from slightly above the average are better at choosing their own sensible strategies for solving the problems, whereas the students from slightly below average are more prone to the rote-learned algorithms. Although, male students appeared to perform better than the female students, the differences in performances are not that high. Thus, the result depicts that there are no significant gender issues in the selected year levels and topics. Further research needs to be carried out in order to determine the relationship between estimation skill and computational ability with topics other than whole and rational numbers, especially in measurement topics. Moreover, such studies can be done involving larger samples, and in other countries as well, Doing so can highlight the importance of the integration of estimation skill in teaching and learning mathematics

Occupational Health and Safety Practices and Challenges in the Construction Industry of Bhutan: A Situation analysis

Introduction: The construction industry is one of the most hazardous industrial fields, wherein the construction workers are prone to work related accidents resulting in disabilities and/or deaths. The probability of fatality in the construction industry is five times more likely than in the manufacturing industry. In developing countries, construction work is ten times more dangerous than in industrialized countries. ILO (2016) estimated that of all workplace accidents, about 30% of fatal accidents occur at construction sites. Similarly, the construction industry in Bhutan accounts for 60% of total workplace accidents in the country.Objective: This paper will evaluate the existing Occupational Health and Safety (OHS) practices in the construction industry of Bhutan. It will also identify the challenges and problems faced by both the contractors and those attempting to implement OHS policies and procedures.Methods: A study was conducted involving 119 participants from several construction companies and government regulatory organizations relevant to the construction industry in Bhutan. Data was collectedthrough questionnaire surveys, interviews and discussions.Results: The study identified a number of OHS problems in the construction industry, including: i) Low priority given to safety; ii) Poor attitude of contractors and laborers towards OHS; iii) lack of competent manpower to enforce regulations; iv) lack of safety promotion; and v) poor health and safety management systems.Conclusion: It is concluded that the biggest challenge faced is to shape the safety culture through behavioral change, of employers and workers. Perhaps most important, however, is the education and training component - not only for the workers, but their managers and supervisors, who must be heldaccountable for workplace safety

Effect of Photocatalysis on the Membrane Hybrid System for wastewater treatment

An integrated photocatalysismembrane hybrid system was investigated for wastewater treatment with the main focus on improving the cross flow microfiltration (MF) permeate flux. Photocatalysis with TiO2 (P25 Degussa) suspension as photocatalyst was applied both as pre-treatment and as inline treatment with MF. The TiO2 slurry was found to have significant effect in permeate flux for wastewater with lower dissolved organic carbon concentration. The MF flux decline due to TiO2 slurry cake on the membrane surface was minimized by allowing the TiO2 slurry to settle and by using only the supernatant for further treatment using the hybrid system. The investigation also included the study on the effect of photocatalytic reaction time and the slurry settling times on the MF permeate flux. The irradiation of ultraviolet on the MF surface in presence of TiO2 catalyst in suspension yielded in an increase in permeate flux

A novel fertiliser drawn forward osmosis desalination for fertigation

University of Technology Sydney. Faculty of Engineering and Information Technology.Agriculture consumes maximum water of up to 70% of the total fresh water withdrawn in the world for consumptive purposes. Rapid population growth is further driving fresh water demand and putting tremendous stress on limited fresh water resources. This increasing demand can only be met by improving the current water use efficiency and by creating new water sources. Desalination could therefore play a significant role in creating a new water source by using unlimited saline water sources. However, current desalination technologies are energy intensive and energy has a significant impact on climate change. If low cost desalination technologies were made available, their impact on agriculture sector would be significant for many water stressed regions of the world. Recently, forward osmosis (FO) has been recognised as one of the most promising low energy processes for desalination. The FO process is based on the principle of natural osmotic process driven by the concentration gradient and not by hydraulic pressure like the reverse osmosis (RO) process and hence requires significantly lower energy. In the FO process, a concentrated draw solution (DS) extracts fresh water from the saline water using special membranes. The issue of membrane fouling in FO process is less challenging than the RO process where fouling constitutes a major operating issue. However, the lack of a suitable DS has limited the application of FO desalination for potable water. The separation of draw solutes from the diluted DS after desalination requires additional post-treatment processes that still consume energy, making FO uncompetitive with the already established RO desalination technology. The FO process offers novelty for those applications where the complete separation of draw solutes is not necessary and where the final diluted DS can be used directly if the presence of draw solutes adds value to the end use. Fertiliser drawn forward osmosis (FDFO) desalination for fertigation is therefore proposed based on this concept. When fertilisers are used as the draw solutes in the FDFO desalination process, the diluted fertiliser solution after desalination can be directly applied for fertigation because fertilisers are essential for plants. This concept avoids the need for an additional post-treatment process for the separation and recovery of draw solutes. The objective of this study is therefore to investigate the performance of the FDFO desalination process for fertigation, identify its limitations and investigate options to overcome these limitations. The study has been presented in eleven chapters that include a definition of the detailed concept and an assessment of the performance of eleven selected fertilisers as the DS under various conditions, through both simulation and bench-scale experiments. The energy required for FDFO for direct fertigation was estimated to be less than 0.24 kW/m3 of fertigation water, which is comparatively lower than the most efficient current desalination technologies. As such, FDFO can also be easily powered using renewable energy sources, such as solar and wind. Since fertilisers are extensively used for agriculture, FDFO desalination does not create additional environmental issues related to fertiliser usage. In fact, FDFO desalination could add more value to irrigation water, thereby providing opportunities for improving the efficiency of water and fertiliser uses. FDFO desalination can be operated at very high feed recovery rates: higher than 80% using a feed of seawater quality. However, FDFO desalination has its own process limitation. Based on the principles of natural osmosis, the net movement of water across the membrane towards the DS cannot theoretically extend beyond osmotic equilibrium, which in turn is limited by the total dissolved solids (TDS) content of the feed solution (FS). Therefore, it is not possible to achieve a concentration of the diluted DS that is lower than the equivalent concentration of the FS without external influence. Based on the models for osmotic equilibrium, the water extraction capacities of eleven selected fertiliser DS were calculated for FS, simulated for different ranges of TDS. The water extraction capacities of the fertilisers were observed to depend on the molecular weight and osmotic pressure of the draw solutes, as well as on feed concentration. Based on the water extraction capacity, the expected fertiliser nutrient concentrations in the final FDFO product water was estimated in terms of nitrogen phosphorous potassium (NPK) concentrations. The expected final nutrient concentrations for simulated brackish water (BW) feed (TDS 5,000–35,000 mg/L) failed to meet acceptable NPK concentrations for direct fertigation of crops. Hence, achieving acceptable nutrient concentrations for direct fertigation will be a major challenge for the FDFO desalination process. The rest of the study therefore focussed on investigating processes and options that would help reduce the nutrient concentrations in the final FDFO product so that the final FDFO product water could be used for direct fertigation. Before the experimental investigation on the FDFO desalination, the influence of major parameters on the performance of FO desalination process was investigated. The thermodynamic properties of the DS play a more influential role on water flux than the thermodynamic properties of the FS at higher temperature. Although water flux comparable to the RO desalination process was obtained by increasing the fertiliser DS concentrations, the internal concentration polarisation effects played a significant role in the performance of the FDFO desalination process. It was observed that any soluble fertilisers with osmotic pressure in excess of the FS can draw water in FO process; however, only eleven different chemical fertilisers commonly used for agriculture worldwide were selected and their performances studied. The performance of the fertiliser solutions as DS were assessed in terms of water flux, reverse draw solute flux, water extraction capacity and nutrient concentrations in the final product water. Blended fertilisers as the DS were able to achieved significantly lower NPK concentrations by FDFO desalination than the straight/single fertiliser as DS. However, it was observed that blending fertilisers generally resulted in a slightly reduced bulk osmotic pressure and water flux compared to the sum of the osmotic pressures and water fluxes of the two individual fertilisers when used as DS alone. An integrated FDFO-NF desalination process was investigated to reduce the nutrient concentrations in the final product water. Nanofiltration (NF) as pre-treatment or post-treatment was found to be effective in reducing the final NPK concentrations to acceptable limits for direct fertigation although it required second NF pass, especially when monovalent fertiliser was used as the DS or when a high TDS feed was used. NF as post-treatment was more advantageous in terms of both nutrient reduction and energy consumption because high quality, diluted DS was used as feed. Finally, this study has recommended a pilot test of the integrated FDFO-NF desalination process in the Murray-Darling basin. Recommendations for further investigations on reducing nutrient concentrations include pressure assisted FDFO desalination and the concept of using osmotic fillers as the DS with fertilisers. The study also recommended evaluating the potential for fertiliser drawn pressure retarded osmosis (FD-PRO) desalination for simultaneous desalination and power generation, and for self-powering the FO desalination process. The other recommendations include a study on membrane fouling and scaling issues for FDFO desalination operated at high recovery rates, boron rejection and, finally, a life cycle analysis of the FDFO desalination process