Infrastructure Engineering - Research Publications

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    Energy Efficient Time Synchronization in WSN for Critical Infrastructure Monitoring
    Rao, AS ; Gubbi, J ; Tuan, N ; Nguyen, J ; Palaniswami, M ; Wyld, DC ; Wozniak, M ; Chaki, N ; Meghanathan, N ; Nagamalai, D (SPRINGER-VERLAG BERLIN, 2011-01-01)
    Wireless Sensor Networks (WSN) based Structural Health Monitoring (SHM) is becoming popular in analyzing the life of critical infrastructure such as bridges on a continuous basis. For most of the applications, data aggregation requires high sampling rate. A need for accurate time synchronization in the order of 0.6 − 9 μs every few minutes is necessary for data collection and analysis. Two-stage energy-efficient time synchronization is proposed in this paper. Firstly, the network is divided into clusters and a head node is elected using Low-Energy Adaptive Clustering Hierarchy based algorithm. Later, multiple packets of different lengths are used to estimate the delay between the elected head and the entire network hierarchically at different levels. Algorithmic scheme limits error to 3-hop worst case synchronization error. Unlike earlier energy-efficient time synchronization schemes, the achieved results increase the lifetime of the network.
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    Applications of phase change materials in concrete for sustainable built environment: a review
    JAYALATH, A ; Mendis, PA ; Gammampila, GR ; Aye, L (ICSECM 2011, 2011)
    The fast economic development around the globe and high standards of living imposes an ever increasing demand for energy. As a prime consumer of world‟s material and energy resources building and construction industry has a great potential in developing new efficient and environmentally friendly materials to reduce energy consumptions in buildings. Thermal energy storage systems (TES) with Phase change materials (PCM) offer attractive means of improving the thermal mass and the thermal comfort within a building. PCMs are latent heat thermal storage (LHTS) materials with high energy storage density compared to conventional sensible heat storage materials. Concrete incorporating PCM improves the thermal mass of the building which reduces the space conditioning energy consumption and extreme temperature fluctuations within the building. The heat capacity and high density of concrete coupled with latent heat storage of PCM provides a novel energy saving concepts for sustainable built environment. Microencapsulation is a latest and advanced technology for incorporation of PCM in to concrete which creates finely dispersed PCMs with high surface area for greater amount of heat transfer. This paper reviews available literature on Phase change materials in concrete, its application and numerical modelling of composite concrete. However most of the existing TES systems have been explored with wallboards and plaster materials and comparatively a few researches have been done on TES systems using cementitious materials. Thus, there is a need for comprehensive experimental and analytical investigations on PCM applications with cementitious materials as the most widely used construction materials in buildings.
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    Application of nanomaterials in the sustainable built environment
    Gammampila, GRG ; Mendis, PAM ; Ngo, TDN ; Aye, LA ; JAYALATH, A ; RUPASINGHE, RAM (University of Moratuwa, 2010)
    Nanotechnology is widely regarded as one of the twenty-first century’s key technologies, and its economic importance is sharply on the rise. In the construction industry, nanomaterials has potentials that are already usable today, especially the functional characteristics such as increased tensile strength, self-cleaning capacity, fire resistance, and additives based on nano materials make common materials lighter, more permeable, and more resistant to wear. Nanomaterial are also considered extremely useful for roofs and facades in the built environment. They also expand design possibilities for interior and exterior rooms and spaces. Nano–insulating materials open up new possibilities for ecologically oriented sustainable infrastructure development. It has been demonstrated that nanotechnology has invented products with many unique characteristics which could significantly provide solutions current construction issues and may change the requirement and organization of construction process. This paper examines and documents applicable nanotechnology based products that can improve the sustainable development and overall competitiveness of the construction industry.
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    Application of nano insulation materials in the sustainable built environment
    Gammampila, GRG ; Mendis, PAM ; Ngo, TDN ; Aye, LA ; Herath, NCH (University of Moratuwa, 2010)
    Nanotechnology is widely being used in the built environment for its advantages in many improved engineering properties of the nano materials. Nano insulating materials open up new possibilities for ecologically oriented sustainable infrastructure development. The most widely used nano material in built environment is for the purpose of insulation to improve the energy efficiency namely in the buildings and dwellings. Nanotechnology has now provided an effective and affordable means to increase energy efficiency in pre-existing buildings as well as new construction by increasing thermal resistance. The major advantage of nano insulation materials is its benefit of translucent coatings which increase the thermal envelope of a building without reducing the square footage. The intrinsic property of nano insulating material is it can be applied to windows to reduce heat transfer from solar radiation due it its thermal resistant property and the translucent property allows diffusing of day light. The nano insulating material has significant advantage in reducing the operational energy aspects of buildings due to its valuable insulating properties. This paper examines applicable nanotechnology based products that can improve the sustainable development and overall competitiveness of the building industry. The areas of applying nano insulating material in building industry will be mainly focused on the building envelope. The paper also examines the potential advantages of using nanotechnology based insulating material in reducing the life cycle energy, reduction of material usage and enhancing the useable life span. The paper also investigates the operational energy by simulation methodology and compares the reduction of operational energy consumption.
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    Trees provide energy saving benefits to adjacent buildings for a small water cost
    Livesley, SJ ; Aye, L ; Hes, D ; DAWKINS, A ; LHENDUP, T ; CAFFIN, M ; Williams, NS (Australian Sustainable Cities and Regions Network, 2011)
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    Template schools: Measuring indoor environmental quality
    Crawford, RH ; Jensen, CA ; Chan, TK ; Hes, D ; Aye, L (The University of Sydney, 2011)
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    A modelling method to assess the effect of tree shading for building performance simulation
    Hes, D ; Dawkins, A ; Jensen, CA ; Aye, L (International Building Performance Simulation Association, 2011)
    Increasing urban tree numbers is a simple but effective means to provide climate change adaptation to the urban environment by reducing the thermal load on buildings. To better communicate and value the importance of urban trees it is necessary to quantify these benefits and to understand the properties and processes that influence the magnitude of these benefits. For this we need verified and effective ways of modelling the trees in modelling software. This paper presents the results and problems encountered when trying to model trees effectively. The aim is to present our approach which was to treat the shade as a shading co-efficient on the wall. This allows for the consideration of the benefits of deciduous versus evergreen species. A modelling method to assess the effect of tree shading was developed and presented in this paper.
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    Engineering electromagnetic metamaterials from coupled cavity arrays
    Quach, J ; Su, CH ; Martin, AM ; Greentree, AD ; Hollenberg, LCL (IEEE, 2011-12-01)
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    Starting to talk about place
    STIRLING, LESLEY ; CAVEDON, LAWRENCE ; RICHTER, DANIELA ; Winter, Stephen ; KEALY, ALLISON ; DUCKHAM, MATT ; RAJABIFARD, ABBAS ; RICHTER, KAI-FLORIAN ; Baldwin, Tim ( 2011)