27 research outputs found
Evaluation of pharmaceutical cream production debottlenecking schemes
The main objective of this work is to model and debottleneck a pharmaceutical production of an anti-allergic cream. The base case process has a minimum cycle time of 29 hours which is equivalent to 66 batches/year. Four schemes were proposed for process debottlenecking due to the anticipated increase of the product demand of 150% in the market. By carrying out throughput analysis study, schemes that fulfil the debottlenecking objective were determined. Out of the four debottlenecking schemes, Scheme 4 was chosen, which proposed a new blending tank and intermediate tank, showed a production increase of over 150%
Atypical Strokes in a Young African American Male: A Case of Mitochondrial Encephalopathy Lactic Acidosis and Stroke-Like Episodes (MELAS) Syndrome
Mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome is a rare but important cause of stroke-like symptoms which can often be missed Thambisetty and Newman 2004. We describe a case of a young male presenting with stroke-like episodes, later diagnosed with MELAS in an attempt to improve the understanding about diagnosing MELAS in the appropriate clinical context
Selection of renewable energy in rural area via life cycle assessment-analytical hierarchy process (LCA-AHP): a case study of Tatau, Sarawak
With a growing global population and energy demand, there is increasing concern about the world’s reliance on fossil fuels, which have a negative impact on the climate, necessitating the immediate transition to a cleaner energy resource. This effort can be initiated in the rural areas of developing countries for a sustainable, efficient and affordable energy source. This study evaluated four types of renewable energy (solar, wind, biomass, and mini-hydro energy) using the integrated Life Cycle Assessment (LCA) and Analytical Hierarchy Process (AHP) approaches to select the best renewable energy source in Tatau, Sarawak. The criteria under consideration in this study included the environment, engineering and economics. The AHP results showed that solar energy received the highest score of 0.299 in terms of the evaluated criteria, followed by mini-hydro, biomass and wind energy, which received scores of 0.271, 0.230 and 0.200, respectively. These findings can be used to develop a systematic procedure for determining the best form of renewable energy for rural areas. This approach could be vital for the authorities that are responsible for breaking down multi-perspective criteria for future decision making in the transition into renewable energy
An integrated fuzzy analytic hierarchy process and life cycle optimization model for microalgae production / Tan Jully
Microalgae biofuel have the potential to overcome many of the limitations and present as a newly emerging clean energy that could replace fossil fuels. To produce a sustainable commodity or product, adverse environmental impacts from the overall process cannot be ignored. Development of cost effective processes for microalgae is considered to be the most significant challenge in commercializing microalgae biofuel production. Optimization of sustainable process plant configuration requires the use of systematic assessment methods in assessing on the usage of natural resources, release of pollutants and generation of environmental impact. The challenges in multi-objective optimization (MOO) is in identifying the appropriate aggregation method to integrate the objectives into a single performance index which is typically done by assigning importance weights to the different objectives. Life cycle assessment (LCA) for microalgae had been conducted extensively focused on comparing its environment impacts for microalgae biofuel production. Researches were also been undertaken to identify the feasible use of different methods for microalgae production. However, there is no consensuses on which of these methods are preferable. Novel integrated fuzzy analytic hierarchy process (FAHP) and life cycle optimization (LCO) framework for microalgae production are presented in this thesis. This includes the insight based on LCA studies and the uncertainty in decision making for technologies selection of microalgae production, taken into consideration of MOO technique. FAHP is incorporated into this research to monitor the uncertainty over the decision making process. Three different microalgae cultivation methods (open pond, tubular photobioreactor and flat-plate photobioreactor), four different harvesting methods (sedimentation by flocculation, flotation, centrifugation and filtration) and four different drying methods (sun drying, spray drying, drum drying and freeze drying) are used as case study to illustrate the capability of integrated FAHP-LCO model. These different methods are evaluated under the three selection criteria, i.e.: production capability, economic and environmental concern. They are prioritized using FAHP. Data from the scientific publication and based on theory for material and balance are used in LCA. Commercial optimization software LINGO v14 are used to solve FAHP and LCO equations. The results showed that flat-plate photobioreactor is preferred among others cultivation system when take into the consideration of environment factors (water, energy and carbon footprint) in the MOO. Followed by filtration and sun drying are chosen as best methods for harvesting and drying processes Sensitivity analysis is conducted and provides insights on the robustness of the decision model and enables the understanding of critical criteria that would significantly influence the ranking of the alternatives. The proposed integrated FAHP-LCO approach therefore proven that it can effectively deal with the uncertainty of judgment in the decision making process in the evaluation of microalgae production selection
Environmental sustainability framework for plastic waste management—a case study of bubble tea industry in Malaysia
Economic growth and rapid industrialisation have led to enormous increase in municipal solid waste (MSW). Lack of waste management alternatives and ineffective waste policy implementation are the major challenges for government to materialise a sustainable solid waste management framework, especially for plastic waste. Booming of the food and beverage (F&B) industry has aggravated the situation by generating more plastic waste with no economic values. Hence, this study aims to evaluate the overall environmental performance of existing and alternative waste management technologies that are available in Malaysia based on net greenhouse gas (GHG) emission in terms of carbon dioxide equivalent (kg CO(2)-eq) per tonne of plastic waste that are analysed through life cycle assessment (LCA) methodology. LCA result has proven that Scenario B (waste to energy (WTE) incineration) is more environmentally preferable as it had a negative net GHG emission of − 573.80 kg CO(2)-eq as compared to GHG emission of existing Scenario A (sanitary landfill) of 566.15 kg CO(2)-eq. Negative net GHG emission in WTE incineration was mainly due to higher GHG saving achieved through cleaner electricity generation as compared to conventional power production. This alternative technology was proven to have the potential to reduce the dependence on landfills and is served as the basis of environmental sustainability framework development for plastic waste management based on case study in Malaysia. This framework can be served as the baseline for the local authorities or policy makers for other plastic waste generation hotspots other than bubble tea industry to improve plastic waste management via WTE incineration
A review of manufacturing sustainability assessment tool selection criteria: A quantitative score-rating system versus process-data sustainability assessment
The scarcity of natural resources has urged the necessity to adopt sustainability practices into current industrial activities. Manufacturing industries have a significant contribution towards socio-economic development by creating job opportunities for the communities and stimulating economic growth. Manufacturing activities are also well-known for their considerably high consumption of natural resources and waste generation. With these underlying issues, research has been actively carried out to develop a holistic framework in both conceptual and practical manners for sustainability improvements, specifically in the manufacturing sectors. Various methods in the research field often lead to the dilemma of selecting the appropriate methods for application. A comprehensive review is desirable to understand the current research efforts by evaluating the specific research problems, methodology developments, and research findings. This paper aims to evaluate the available sustainability assessment methods that were demonstrated with case studies, thereby defining the common practices adopted by the researchers in opting for their preferred methods. A systematic review was conducted to identify the common selection criteria for sustainability assessment methods. This study could provide a holistic insight to streamline the available options and justify their selection according to the application needs
Multiple biogenic waste valorization via pyrolysis technologies in palm oil industry:economic and environmental multi-objective optimization for sustainable energy system
Comparative study of a life cycle assessment for bio-plastic straws and paper straws:Malaysia’s perspective
Plastics are used for various applications, including in the food and beverage industry, for the manufacturing of plastic utensils and straws. The higher utilization of plastic straws has indirectly resulted in the significant disposal of plastic waste, which has become a serious environmental issue. Alternatively, bio-plastic and paper straws have been introduced to reduce plastic waste. However, limited studies are available on the environmental assessment of drinking straws. Life cycle assessment (LCA) studies for bio-plastic and paper straws have not been comprehensively performed previously. Therefore, the impact of both bio-plastic and paper straws on the environment are quantified and compared in this study. Parameters, such as the global warming potential (GWP), acidification potential (AP) and eutrophication potential (EP), were evaluated. The input–output data of the bio-plastic and paper straws processes from a gate-to-grave analysis were obtained from the literature and generated using the SuperPro Designer V9 process simulator. The results show that bio-plastic straws, which are also known as polylactic acid (PLA) straws, had reduced environmental impacts compared to paper straws. The outcomes of this work provide an insight into the application of bio-plastic and paper straws in effectively reducing the impact on the environment and in promoting sustainability, especially from the perspective of Malaysia
Integrated capacity and inventory decisions
International Conference on Operations Research (OR 2011), August 30 - September 2, 2011, Zurich, SwitzerlandThis paper deals with the simultaneous acquisition of capacity and material in a situation with uncertain demand, with non-zero lead-times for the supply of both material and capacity. Although there is a lot of literature on the time-phased acquisition of capacity and material, most of this literature focuses on one of the two decisions. By using a dynamic programming formulation, we describe the optimal balance between using safety stocks and contingent workforce for various lead-time situations. We compare the cost ingredients of the optimal strategy with the standard inventory approach that neglects capacity restrictions in the decision. The experimental study shows that co-ordination of both decisions in the optimal strategy leads to cost reductions of around 10%.We also derive characteristics of the optimal strategy that we expect to provide a thorough basis for operational decision making.nonouirechercheInternationa