205 research outputs found

    High performance blended membranes using a novel preparation technique

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    The possibility of applying novel microwave (MW) technique in the dissolution of polyethersulfone (PES) and lithium halides in aprotic solvent is studied. The lithium halides additives used are lithium fluoride (LiF), lithium bromide (LiBr) and lithium chloride (LiCl) and a comparison is made with conventional method. PES was dissolved in dimethylformamide (DMF) in the single solvent whilst for the double solvent (DS); PES was dissolved in a mixture of two different solvents DMF and acetone. The concentrations of lithium halide in both solvents were varied from 1 to 5 wt%. In order to illuminate the mechanism through which lithium halide influences the kinetic membrane performance in both techniques, rheological, FTIR, contact angle and water uptake analysis were performed. The performances of the membranes were evaluated in terms of pure water permeation (PWP), permeation rate (PR) and separation rates of various polyethylene glycols. Result revealed that the hollow fiber MW membrane with the 3 wt% LiBr additive exhibits both high permeation rates of 222.16 Lm-2hr-1 and separation rates of 99% and molecular weight cutoff (MWCO) of 2.6 kDa. In general, the MW membranes exhibited higher permeation and separation rates compared to conventional electrothermal heating (CEH) membranes. The FTIR, contact angle and water uptake measurement revealed that the LiCl and LiBr have enhanced the hydrophilic properties of the PES membranes thus producing membrane with high permeation and separation rates

    Sustainability of product life cycle: a case study of hollow fiber membrane

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    The world’s supply of fresh water is finite and threatened by pollutions such wastewater distributed from industries. Membrane technology has received increasing attention for the wastewater treatment lately [Kumar et al., 2014; Melin et al., 2006]. The membrane function performance usually identified, while the performance from sustainability perspective have received less attention.In line with the Malaysian government policy, the membrane system used for wastewater treatment needs to be scrutinized to ensure sustainability according to Triple Bottom Line aspects including environmental, social and economic. However, this paper focusing on environmental sustainability aspects. The potential environmental burdens calculated are global warming potential (GWP), acidification potential (AP), eutrophication potential (EP) and waste potential (EP)

    A conceptual sustainable domain value stream mapping framework for manufacturing

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    Part of: Seliger, Günther (Ed.): Innovative solutions : proceedings / 11th Global Conference on Sustainable Manufacturing, Berlin, Germany, 23rd - 25th September, 2013. - Berlin: Universitätsverlag der TU Berlin, 2013. - ISBN 978-3-7983-2609-5 (online). - http://nbn-resolving.de/urn:nbn:de:kobv:83-opus4-40276. - pp. 54-59.Adoption of lean manufacturing generally involves waste reduction and its adoption has been successful in improving companies. With increasing awareness on the need for sustainable development, works have been done on sustainability assessment of product design and manufacturing processes. The sustainable manufacturing, 6R method can be adopted to improve the existing design and manufacturing sustainability scores. A conceptual hybrid framework integrating lean manufacturing with sustainable manufacturing theories has been developed thus enabling the benefits from both techniques to be gained. Specifically, the lean manufacturing, value stream mapping tool is integrated with the sustainable manufacturing, 6R method to assist in solving manufacturing problems at process and or plant level sustainably. An indicator, providing the sustainability scores on value adding and non value adding elements at present and future state, has been proposed as part of the framework

    Low carbon emissions review in aviation engine technology for Asean airspace: a proposal

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    Air tranportation has been major mode of connecting role player in business supply chain and catalyst for tourism industry. Emission from aircraft engines do produce various gasses as by product of combustion. Thus in this paper the authors focus on gas turbine engine emissions in accordance to ICAO Annex 16 emission protection recommendations. Majority of the aircraft are fitted with gas turbine engines for propulsion. The United States Federal Aviation Administration (FAA) and European Aviation Safety Agency (EASA) emission documents were studied. Cabon in this context is CO2 directly related to fuel consumption by the engine. The engine emission consist of NOx , HC, CO2 and smoke. However with various initiatives aircraft today 15 percent reduction in fuel burn, 40 percent lower in emission compared to a decade ago (ICAO Environmental report 2010) The FAA have launched the continuous lower energy, emissions and noise (CLEEN) program in 2010. The goal of the CLEEN program is to noise and emissions reduction by aircraft and engine technology. Another improvement was the alternative fuel deployment and development project. This project known as “Farm to Fly” and base on this initiative development three alternative jet fuels approved for aviation use by ASTM standards. FAA also developing a proposed Global Market Based Measure (GMBM) for metrics of measurement. These holistic program known as “Next Generation Air Transportation System” or NextGen. NextGen has five pillars of strategy. (US Aviation GHG reduction plan 2015)

    Qualitative theory building method for lean sustainable framework development: a methodology

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    Research in manufacturing engineering was commonly conducted by employing quantitative methodology. Experimental and survey questionnaire methods are widely used by researchers. Hence, this paper will explain the justification for using the mix method of grounded theory and survey questionnaires to develop a lean sustainable framework. The authors used a non conventional method in mechanical engineering to develop the framework. The research method was classified as interpretative method. The grounded theory method is used to link the collected data until the emergence of an inductive theory generation. The rigor of the research was based on triangulation. Triangulation method improves the reliability and validity of the research. The end product of this research was the development of lean sustainable framework

    Determination of energy consumption during turning of hardened stainless steel using resultant cutting force

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    Downsizing energy consumption during the machining of metals is vital for sustainable manufacturing. As a prerequisite, energy consumption should be determined, through direct or indirect measurement. The manufacturing process of interest is the finish turning which has been explored to generate (near) net shapes, particularly for hardened steels. In this paper, we propose using measured cutting forces to calculate the electrical energy consumption during the finish turning process of metals where typically the depth of cut is lower than the cutting tool nose radius. In this approach, the resultant cutting force should be used for calculating the energy consumption, instead of only the main (tangential) cutting force as used in the conventional approach. A case study was carried out where a hardened stainless steel (AISI 420, hardness of 47–48 HRC) was turned using a coated carbide tool, with a nose radius of 0.8 mm, without cutting fluid, and at 0.4 mm depth of cut. The experimental design varied the cutting speed (100, 130, and 170 m/min) and feed (0.10, 0.125, and 0.16 mm) while other parameters were kept constant. The results indicate that the electrical energy consumption during the particular dry turning of hardened steel can be calculated using cutting force data as proposed. This generally means machining studies that measure cutting forces can also present energy consumption during the finish or hard turning of metals, without specifically measuring the power consumption of the machining process. For this particular dry turning of hardened stainless steel, cutting parameters optimization in terms of machining responses (i.e., low surface roughness, long tool life, low cutting force, and low energy consumption) was also determined to provide an insight on how energy consumption can be integrated with other machining responses towards sustainable machining process of metals

    The impact of social and security factors on residential site suitability by using GIS-based MCDM approach: a case study the city of Kirkuk, Iraq

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    Unplanned population growth, alongside unplanned development, lack of good housing and inadequate infrastructure resulted in a lot of slums and informal settlements in Iraqi cities. In 1980s there were major housing shortage in Iraq as a result of war and political instability which led to economic meltdown. Kirkuk city was one of the most affected cities by multiethnic crises as a result of employment, housing and local government members’ concentration in Kirkuk which led to political and economic migration. Suitable site selection for housing is complicated not just because it has to do with technical procedures and topography but due to environmental, social and political issues which can lead to conflict. Hence, this study seeks to discover the suitable site selection for housing using Geographical Information System (GIS), high resolution remote sensing data and multi criteria analysis (MCA)

    Voting trends in Bukit Selambau by-election Malaysia

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    The Bukit Selambau by-election was due to the previous ADUN’s of Bukit Selambau, YB.V Arumugam’s resignation and this had caused SPR to supervise another by-election on the 7th of April 2009. The local population had shown the tendency to support the People’s Coalition (PR) rather than side with the Barisan Nasional (BN). The objectives of this research are to identify the voting trends of Bukit Selambau by- election and to determine the most trends influencing the voting pattern in this by-election. The findings on the observations and interviews that were done concluded that the candidates’ ethnicity, religion, and age played an important role in the Bukit Selambau by-election. As a result, the PR had won even though its candidate S. Manikumar was not well known and BN’s candidate BN Datuk S. Ganesan who was very popular, lost the by-election. BN needs to remember that after the political tsunami that hit a year ago, popular candidates do no guarantee victory to the contesting parties even though there were 50.2 % Malay voters in Bukit Selambau. BN’s failure to take back Bukit Selambau should be taken as an lesson to be learned, in which a more ’people friendly’ campaign should be done later on. In reality, the Malays should stay together so that the political tsunami of PRU 12 will not take place in the upcoming PRU 13. The recommendations were made to the State Government, local society and future research by participating from all parties including citizen in process voting trends more transparency

    Effect of freeze-drying and gamma irradiation on biomechanical properties of bovine pericardium

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    Freeze-drying and gamma irradiation are the techniques widely use in tissue banking for preservation and sterilization of tissue grafts respectively. However, the effect of these techniques on biomechanical properties of bovine pericardium is poorly known. A total of 300 strips of bovine pericardium each measured 4 cm × 1 cm were used in this study to evaluate the effect of freeze-drying on biomechanical properties of fresh bovine pericardium and the effect of gamma irradiation on biomechanical properties of freeze-dried bovine pericardium. The strips were divided into three equal groups, which consist of 100 strips each group. The three groups were fresh bovine pericardium, freeze-dried bovine pericardium and irradiated freeze-dried bovine pericardium. The biomechanical properties of the pericardial strips were measured by a computer controlled instron tensiometer while the strips thickness was measured by Mitutoyo thickness gauge. The results of the study revealed that freeze-drying has no significant (p > 0.05) effect on the tensile strength, Young’s modulus (stiffness) and elongation rate of fresh bovine pericardium. Irradiation with 25 kGy gamma rays caused significant decreased in the tensile strength, Young’s modulus and elongation rate of the freeze-dried pericardium. However, gamma irradiation has no significant effect on the thickness of freeze-dried bovine pericardium, while freeze-drying caused significant decreased in the thickness of the fresh bovine pericardium. The outcome of this study demonstrated that freeze-drying has no significant effect on the biomechanical properties of fresh bovine pericardium, and gamma irradiation caused significant effect on the biomechanical properties of freeze-dried bovine pericardium

    Honey hydrogel dressing to treat burn wound in rats - a preliminary report

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    Various studies have shown that honey is effective in healing burns and wounds. In this study, Malaysian honey was incorporated into hydrogel dressing formulation using electron beam irradiation technique and introduced as Honey Hydrogel dressing. The wound healing efficacy of Honey Hydrogel dressing on deep partial thickness burns was monitored on the basis of gross appearances, rate of wound contraction and histopathological changes. Deep partial thickness burns were created by applying an aluminium template preheated to 85°C to the backs of rats for 5 s and randomly treated with Honey Hydrogel or hydrogel while control group received no treatment. Wound appearance was photographed and the rate of wound contraction was calculated at 7, 14, and 21 days post burn. Rats were euthanized after 21 days of treatment and skin samples were taken for histopathological examination. The wounds treated with Honey Hydrogel dressing showed better gross appearances and significantly (p<0.05) enhanced the rate of wound contraction as compared to the control group at 21 days post burn. Faster epithelialization was also seen in the Honey Hydrogel treated group as compared to the other groups, although this was not statistically significant. The results substantiate the potential efficacy of Honey Hydrogel in accelerating burn wound healing
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