Evaluation of high density polyethylene plastic bag performance towards edge and point stresses using taguchi method

Plastic bag are widely used due to it is low cost and convenience for packaging items. The problem with the strength of the plastic bag tends to tear easily and perforated. This study aims to validate the simulation results of High Density Polyethylene (HDPE) plastic towards HDPE plastic bags manufactured in UTHM and thus to evaluate the performance of plastic bag towards mass, edge and point stresses. The tensile test simulation was conducted using Solidworks 2017 to validate the HDPE plastic material properties by comparing the tensile test performed according to ASTM D882-18. The real life application was conducted to validate the simulation result by comparing plastic film’s displacement with different mass applied. Taguchi Method was used to arrange the edge and point stress test parameter with varied angle, mass, length and distance between the loads. The result showed that the error percentage for all loads was lower than 10.00 % for simulation compared to experimental tensile test. It also showed that error percentage was less than 5.00 % by comparing real life application and simulation results for displacement of plastic film. For mass stress test, the loads with 5.0 kg square base has the highest stress acted on the plastic film’s surface which is 22.399 MPa. For edge stress test, sample D with 1.0 kg, 20 mm of edge’s length and 20 ° of edge’s angle have highest maximum stress and displacement acted on plastic film’s surface which are 34.086 MPa and 84.94 mm respectively. For point stress test, sample G with 1.0 kg, 10 ° of angle and 30 mm of the distance between the point load have highest maximum stress and displacement acted on surface of plastic film which are 50.676 MPa and 63.64 mm accordingly. Both sample D and G were perforated since the maximum stress acted was exceed the tensile strength of HDPE plastic which is 28.4 MPa. The validation of HDPE plastic towards HDPE plastic bag manufactured in UTHM was proven from the result obtained. The plastic bag’s performance towards mass, edge and point stresses was successfully evaluated by using Finite Element Analysis and Taguchi Method

British Conceptions of Wealth and Property in the East Indies and their Influence on Governance and Society: 1807-1824

The British East India Company's invasion of Java in 1811 is regarded by historians to have paved the way for the Company's founding of a free port in Singapore by Sir Stamford Raffles in 1819. Raffles's references to Adam Smith's 1776 treatise, The Wealth of Nations, in his 1817 History of Java have reinforced the view that he had adopted Smith's liberal principles of political economy when he was governor of Java from 1811 to 1816. A closer inspection, however, shows Raffles's policies to have instead protected monopolies, restricted markets, and regulated people's lives. From this contradiction had arisen the historical problem of how the two events of Java's invasion and Singapore's founding were connected. Historians maintain that, though later inspired by free trade, Raffles was initially bound to the mercantilist interests of the Company. Yet the Company's Governor-General, the Earl of Minto, had in Java introduced some of the first emancipatory laws and civil reforms of the modern era. What were the British really doing in the East Indies between 1811 and 1819? In this thesis, I answer this question by showing that these contradictions had arisen from the historian's assumption that ideological relations had determined Raffles's and Minto's policies. I show instead that the linguistic contexts of those policies, when examined, reveal not contradiction but a general criticism of both 'liberalism' and 'mercantilism'. Raffles, Minto, and the third actor in this study, John Leyden, had held moral and political views which were sceptical of political economy's claims to deliver productivity and surplus. While virtue and the ideal of freedom had brought material progress, they were believed to have also led to vice, slavery, and human decline. This conception of the human condition identifies a civic humanist discourse and a common sense philosophy that were prominent in eighteenth-century Britain. They influenced an ethical approach to empire that was radically opposed to both Franco-Dutch and British colonialism. In the East Indies, Raffles, Minto, and Leyden resolved to end the power of a moneyed interest over the native population and restore the native individual's self-consciousness and self-dependence. These events defined a 'venture of critique' which saw the Company effectively decolonise Napoleonic Java and lay the foundations for a native commonwealth that encompassed the Malay Archipelago and which was centred at Singapore. They articulate an historical moment when the established narrative of modern empire is interrupted by a narrative of the classical republic. Such a moment entirely overturns the conventional understanding of the historical relation between Britain and the Malay States. By introducing humanist conceptions of wealth and property into the colonial and oriental discourse, it changed existing forms of society and governance in the East Indies and profoundly determined future forms of society and governance in nineteenth-century British Malaya and twentieth-century Malaysia and Singapore

Cognitive health of older persons in longitudinal ageing cohort studies

Dementia poses a major global burden of care to society and health systems in ageing populations. The majority (over 60%) of persons with dementia in the world are found in Asia and developing countries with rapid rates of population ageing. Improving and maintaining the cognitive health of older persons is vital to national strategies for dementia prevention. Increasing numbers of population-based ageing cohort studies in the past decade have provided a better understanding of the factors that contribute to cognitive function and decline in old age. The roles of major demographic, psychosocial, lifestyle, behavioral and cardiovascular risk factors contributing to cognitive health were discussed using examples from the Singapore Longitudinal Ageing Studies. They include socio-demographic factors, particularly education and marital status, leisure time activity such as physical activity, social engagement and mental activities, psychological factors such as depression, cardiovascular and metabolic risk factors: obesity, diabetes, hypertension and dyslipidemia, and the metabolic syndrome, under-nutrition, low albumin, low hemoglobin, nutritional factors such as blood folate, B12 and homocysteine, omega-3 poly-unsaturated fatty acids, tea drinking and curcumin-rich turmeric in curry meals. These factors are found to be associated variously with cognitive functions (memory and learning, language, visuospatial, attention and information processing speed), rates of cognitive impairment and cognitive decline, or increased risk of developing MCI and progression to dementia

THE EFFECT OF TRADABLE DISCHARGE PERMIT (TDP) PROGRAMS ON THE RELIABILITY OF WATER QUALITY IN RIVERS

Tradable Discharge Permit (TDP) programs have shown, both in practice and in theory, to have tremendous potential as cost-effective methods of pollution control. Nevertheless, there are still many uncertainties regarding TDP programs that if not adequately addressed, might impair their success. Concerns range from issues of market failure that prevents optimal trading, to political agendas that differ from a typical TDP program in their priorities, to modeling difficulties that might cause erroneous predictions of cost savings and environmental performance. The hopelessness of trying to overcome these concerns all at once is recognized. And therefore, apart from a brief discussion where the more common of these uncertainties are identified and discussed, attention is focused only on the uncertainty associated with environmental modeling, specifically that associated with the stochastic aquatic environment. Numerous studies have been carried out to predict the potential impacts of TDP programs, whether positive or negative, on the environment they are intended to protect. These studies have been invaluable in laying essential groundwork for the further understanding and actual implementation of such programs. However, many of these studies assumed deterministic environmental models when in reality nothing is ever constant. The environment is an open system vulnerable to, amongst many other agents, weather variations and changes in microbial behavior. It is therefore, this study's goal to attempt to advance a step forward by re-assessing those same questions asked many times before, but this time without disregarding the stochastic nature of the environment. The Willamette and Athabasca Rivers in Oregon, USA and Alberta, Canada, respectively are used as example case studies. These systems are simulated to predict how they might respond if discharge permit trading were implemented. The Mean-Value First-Order Second-Moment (MFOSM) method is used to evaluate the reliability of each system's dissolved oxygen (DO) concentration meeting set standards, as a function of its BOD wasteload distribution and environmental randomness. The results show that trading does indeed influence environment quality. For the Willamette River, trading improves the water quality reliability. For the Athabasca River, trading makes the reliability worse. However, these effects are quite minimal in that, for any target reliability to be achieved that is reasonable, trading is found not to change the reliability significantly in comparison to that attained under a policy of no trading

Environmental Systems Analysis - Hong Kong University of Science and Technology, Hong Kong

Undergraduate course in environmental systems analysis offered at Hong Kong University of Science and Technology, Hong Kong in Fall 2015

Hydrothermal Carbonisation of Palm Oil Mill Effluent

Hydrothermal carbonisation (HTC) is a thermochemical process that converts organic wastes into a coal-like material named ‘biochar’ or’ hydrochar’. The process involves application of high temperature and pressure to solid biomass in a suspension with water for several hours. Palm oil refining industry is one of the largest industries in Malaysia. Consequently, the volume of Palm Oil Mill effluent (POME) generated would be massive. This polluting oily waste water always causes environmental issues and requires certain cost for its treatment before discharge. The objective of the project is to verify the potential of HTC process to upgrade or treat POME, to study the effect of temperature, formaldehyde concentration, pH value and feed solid:water ratio towards hydrothermal carbonisation of POME and also the significance of each factor to the quality of hydrochar generation and lastly to select the optimum operating condition. Based on literature review, most researches are commonly done with the solid biomass. However, there are no wide studies on HTC process on waste in sludgy liquid form for example palm oil mill effluent. In this project, the scope will be focusing on producing hydrochar from POME. The quality of hydrochar will be analysed using Heating Value Analysis, Ash Content Analysis, and Carbon content. Taguchi method is implemented in this project to simplify and reduce the duration required for the project. This method adds the context of quality engineering into the common HTC studies. The result of the experiment shows that HTC process has high potential to upgrade POME to higher value product. Increasing temperature and humidity reduces yield and ash content but increases heating value and carbon content. Increasing formaldehyde concentration gives positive results to all the parameters. The effect of temperature and formaldehyde concentration is more dominant in HTC process. The suggested operating conditions for HTC process are 270oC, 2.5 wt% Formaldehyde concentrations and 88.05% humidity which is the originally obtained POME

A Learning-by-Doing Energy Model on Dynamic Programming

The concept of learning by doing (LBD) rests on the assumption that the more we do something, the more efficient we become at it. the inclusion of this phenomenon in our models results in a non-convex formulation and the possibility of multiple local optimal solutions. In this paper, we present a dynamic programming formulation of a model with learning-by-doing. The main advantage of this formulation is the guarantee of a global optimal solution, as conventional nonlinear solvers generally return local optimal solutions with no guarantee of global optimality. We also present two nonlinear extensions to the model that are not easily solved with some other heuristics. We conclude by running the model based on three carbon tax cases and a discussion of the results

String Theory and Turbulence

We propose a string theory of turbulence that explains the Kolmogorov scaling in 3+1 dimensions and the Kraichnan and Kolmogorov scalings in 2+1 dimensions. This string theory of turbulence should be understood in light of the AdS/CFT dictionary. Our argument is crucially based on the use of Migdal's loop variables and the self-consistent solutions of Migdal's loop equations for turbulence. In particular, there is an area law for turbulence in 2+1 dimensions related to the Kraichnan scaling.Comment: LaTeX; 15 pages, two figures; v.2: slight changes to text, footnotes and references adde