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Full-Text Articles in Engineering

Evaluating The Optical Properties Of Tio2 Nanofluid For A Direct Absorption Solar Collector May 2015

Evaluating The Optical Properties Of Tio2 Nanofluid For A Direct Absorption Solar Collector

Faculty of Engineering University of Malaya

Recent studies specify that designated nanofluids may increase the proficiency of direct absorption solar thermal collectors. To determine the efficiency of nanofluids in solar applications, their capability to change light energy to thermal energy must be identified (i.e., the absorption spectrum of the solar material). In view of that, this study compares model predictions to spectroscopic measurements of extinction coefficients over wavelengths that are important for solar energy (200- 1100nm). In the first decade of nanofluid research, most of the focus was on measuring and modeling the fundamental thermophysical properties of nanofluids (i.e., thermal conductivity, density, viscosity, and convection coefficients). …


A Review Of Life Cycle Assessment Method For Building Industry May 2015

A Review Of Life Cycle Assessment Method For Building Industry

Faculty of Engineering University of Malaya

A recent study suggested that buildings globally consume up to 40% of energy and responsible for half of world greenhouse gas emission. Introducing life cycle assessment (LCA) to the building industry is important because it can measure every environmental impact involved in every process from cradle to grave systematically. Within the last decade, research on LCA has increased covering from construction process to manufacturing of building materials. The methods to assess buildings are diverse as buildings have different functions, materials, sizes and locations. The aim of this article is to review the LCA methods and to distinguish phases and materials …


An Experimental Investigation On A Single Tubular Sofc For Renewable Energy Based Cogeneration System Apr 2015

An Experimental Investigation On A Single Tubular Sofc For Renewable Energy Based Cogeneration System

Faculty of Engineering University of Malaya

Having negative impacts on environment and the scarcity of resources of conventional fossil fuels, fuel cell technology draws more attention as an alternative for providing the electrical energy in parallel with thermal energy. In this study, a single tubular solid oxide fuel cell (SOFC) with an electrolyte of Yttria-Stabilized Zirconia 8 mol% ceramic powder was experimentally investigated. The investigation illustrated the effects of three different fuel flow-rates (175 ml/min, 250 ml/min and 325 ml/min) and two operating temperatures (650 degrees C and 750 degrees C) on the output electrical and thermal powers. The highest electrical voltage (open circuit) and overall …


Assessment Of Ghg Emission Reduction Potential From Source-Separated Organic Waste (Sow) Management: Case Study In A Higher Educational Institution In Malaysia Feb 2015

Assessment Of Ghg Emission Reduction Potential From Source-Separated Organic Waste (Sow) Management: Case Study In A Higher Educational Institution In Malaysia

Faculty of Engineering University of Malaya

In Malaysia, the greenhouse gases (GHGs) emissions reduction via composting of source-separated organic waste (SOW) in municipal solid waste (MSW) has not been assessed. Assessment of GHG emissions reduction via composting of SOW is important as environmental impacts from waste management are waste-specific and local-specific. The study presents the case study for potential carbon reduction via composting of SOW in University of Malaya (UM). In this study, a series of calculations were used to evaluate the GHG emission of different SOW management scenarios. The calculations based on IPCC calculation methods (AM0025) include GHGs emissions from landfilling, fuel consumption in transportation …


Design And Biomechanical Performance Analysis Of A User-Friendly Orthotic Device Jan 2015

Design And Biomechanical Performance Analysis Of A User-Friendly Orthotic Device

Faculty of Engineering University of Malaya

Material selection and proper design are essential for developing a new product, especially biomedical devices. Stance-control-orthosis (SCO) are walking assistive device for the patients with weak quadriceps. This manuscript presents the development of a prefabricated SCO with suitable material and design. It is 45% lighter than commercially available prefabricated device. It contains some adjustable features to make it competent for wide range of patients in terms of height (153-183 cm) and weight. Finite element analysis (FEA) was used for selecting the best material and optimizing weight of different components of this device. Basic structures the device were made of aluminum …


Q-Switched Erbium Doped Fiber Laser Based On Single And Multiple Walled Carbon Nanotubes Embedded In Polyethylene Oxide Film As Saturable Absorber Jan 2015

Q-Switched Erbium Doped Fiber Laser Based On Single And Multiple Walled Carbon Nanotubes Embedded In Polyethylene Oxide Film As Saturable Absorber

Faculty of Engineering University of Malaya

A passive, stable and low cost Q-switched Erbium-doped fiber laser (EDFL) is demonstrated using both single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs), which are embedded in polyethylene oxide (PEO) film as a saturable absorber (SA). The film is sandwiched between two FC/PC fiber connectors and integrated into the laser cavity for Q-switching pulse generation operating at wavelength of 1533.6 am. With SWCNTs, the laser produces a stable pulse train with repetition rate and pulse width ranging from 9.52 to 33.33 kHz and 16.8 to 8.0 is while varying the 980 am pump power from 48.5 mW to 100.4 …