University of Malaya

About: University of Malaya is a education organization based out in Kuala Lumpur, Malaysia. It is known for research contribution in the topics: Population & Fiber laser. The organization has 25087 authors who have published 51491 publications receiving 1036791 citations. The organization is also known as: UM & Universiti Malaya.

Evolution of solid waste management in Malaysia: impacts and implications of the solid waste bill, 2007

Abstract: Solid waste generation and its implications for people and the environment are global issues. The complexity of the waste composition and the ever-increasing percapita waste generation is a challenge for waste managers, particularly in developing countries. Thus, the need to have a clear policy on waste management and legislation to realize that policy is imperative. Malaysia is developing rapidly and problems such as the waste generation associated with development and industrialization are evident. The Solid Waste and Public Cleansing Management Bill, which was approved in August 2007 after a 10-year delay, is envisaged to have serious consequences in waste management practices and implementation in Malaysia. This article explores the main features of this all-encompassing bill and its impacts on the waste management scenario in Malaysia. In addition, a comparative evaluation is also discussed to explore the policies/legislation of selected countries vis-avis the Malaysian bill.

Mathematical modeling of solid oxide fuel cells: A review

Abstract: This paper presents a review of studies on mathematical modeling of solid oxide fuel cells (SOFCs) with respect to the tubular and planar configurations. In this work, both configurations are divided into five subsystems and the factors such as mass/energy/momentum transfer, diffusion through porous media, electrochemical reactions with and without CO oxidation, shift and reforming reactions, and polarization losses inside the subsystems are discussed. Using variety of fuels fed to SOFCs is issued and their effect on the system is compared briefly. A short review of solid oxide fuel cell configurations and different flow manifolding are also presented in this study. Novel models based on statistical data-driven approach existing in the literatures are considered shortly. Although many studies on solid oxide fuel cells modeling have been done, still more research needs to be done to improve the models in order to predict the fuel cell behaviors more accurately. At the end of this paper the works and studies that can be done for improving the fuel cell models is suggested and pointed by the authors.

Sustainability of direct biodiesel synthesis from microalgae biomass: a critical review.

Abstract: Microalgae has been identified as a potential feedstock for biodiesel production since its cultivation requires less cropland compared to conventional oil crops and the high growth rate of microalgae. Research on microalgae oils often are focused on microalgae oil extraction and biomass harvesting techniques. However, energy intensive and costly lipid extraction methods are the major obstacles hampering microalgae biodiesel commercialisation. Direct biodiesel synthesis avoids such problems as it combines lipid extraction techniques and transesterification into a single step. In this review, the potential of direct biodiesel synthesis from microalgae biomass was comprehensively analysed. The various species of microalgae commonly used as biodiesel feedstock was critically assessed, particularly on high lipid content species. The production of microalgae biodiesel via direct conversion from biomass was systematically discussed, covering major enhancements such as heterogeneous catalysts, the use of ultrasonic and microwave- techniques and supercritical alcohols that focus on the overall improvement of biodiesel production. In addition, this review illustrates the cultivation conditions for biomass growth and lipid productivity improvement, the available harvesting and lipid extraction technologies, as well as the key challenges and future prospect of microalgae biodiesel production. This review serves as a basis for future research on direct biodiesel synthesis from modified microalgae biomass to improve profitability of microalgae biodiesel.