Infrastructure Engineering - Research Publications
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ItemThe carbon footprint of treating patients with septic shock in the intensive care unit(College of Intensive Care Medicine of Australia and New Zealand, 2018-12-01)OBJECTIVE: To use life cycle assessment to determine the environmental footprint of the care of patients with septic shock in the intensive care unit (ICU). DESIGN, SETTING AND PARTICIPANTS: Prospective, observational life cycle assessment examining the use of energy for heating, ventilation and air conditioning; lighting; machines; and all consumables and waste associated with treating ten patients with septic shock in the ICU at BarnesJewish Hospital, St. Louis, MO, United States (US-ICU) and ten patients at Footscray Hospital, Melbourne, Vic, Australia (Aus-ICU). MAIN OUTCOME MEASURES: Environmental footprint, particularly greenhouse gas emissions. RESULTS: Energy use per patient averaged 272 kWh/day for the US-ICU and 143 kWh/day for the Aus-ICU. The average daily amount of single-use materials per patient was 3.4 kg (range, 1.0-6.3 kg) for the US-ICU and 3.4 kg (range, 1.2-8.7 kg) for the Aus-ICU. The average daily particularly greenhouse gas emissions arising from treating patients in the US-ICU was 178 kg carbon dioxide equivalent (CO2-e) emissions (range, 165-228 kg CO2-e), while for the Aus-ICU the carbon footprint was 88 kg CO2-e (range, 77-107 kg CO2-e). Energy accounted for 155 kg CO2-e in the US-ICU (87%) and 67 kg CO2-e in the Aus-ICU (76%). The daily treatment of one patient with septic shock in the US-ICU was equivalent to the total daily carbon footprint of 3.5 Americans' CO2-e emissions, and for the Aus-ICU, it was equivalent to the emissions of 1.5 Australians. CONCLUSION: The carbon footprints of the ICUs were dominated by the energy use for heating, ventilation and air conditioning; consumables were relatively less important, with limited effect of intensity of patient care. There is large opportunity for reducing the ICUs' carbon footprint by improving the energy efficiency of buildings and increasing the use of renewable energy sources.
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ItemOpening the door on refrigerator energy consumption: quantifying the key drivers in the home(SPRINGER, 2018-08)There is little concrete understanding of the energy consumption of refrigerating appliances during normal use or the main influences on their energy consumption. To date, no widely accepted method to disaggregate measured energy consumption measured in the home into its key components has been demonstrated. This paper examines the main external factors that impact on the energy consumption of existing refrigerating appliances in the home and how they respond to changing conditions, namely: room air temperature, defrosting behaviour and user interactions. Analysis of field data from 235 homes in Australia demonstrates that room air temperature is by far the largest factor accounting for typically around 75% of total energy consumption. Where present, energy used for defrosting is relatively small at around 10%, but this does vary by household and the type of defrost controller. User interactions typically account for 15% of total energy consumed by main household refrigerating appliances, but this varies from a few percent to as much as 45% in large households. The method set out in this paper provides a basis for more in depth analysis and a better understanding of energy consumption of household refrigerators in different regions.
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ItemA Machine Learning Approach for the Performance Prediction of GCHPs with Horizontal Ground Heat Exchangers(IOS PRESS, 2019-01-01)This study aims to provide a machine learning approach to predict the performance of Ground Coupled Heat Pumps (GCHPs) with horizontal Ground Heat Exchangers (GHEs). Specifically, an ANN model was developed for this purpose which can potentially be generally applied to similar sites at different locations and climate conditions, with even limited types of input data. In this example, a TRNSYS model regarding a typical horizontal trench within a rural farm in Australia, has been developed and verified, covering over 50 different yearly loading patterns under 3 different climate conditions. The simulated performance data is then used to train the artificial neural network. As results, the trained ANN is able to predict the performance of GSHPs systems with identical GHEs even under climatic conditions (and locations) that has not been specifically trained for. With only limited input data, the presented ANN shows no more than 5% error in most cases tested.
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ItemLocal walkability index: assessing built environment influence on walking(SCIENDO, 2019-12)Abstract Walking is a more sustainable transport mode, and governments around the world are trying to deliver highly walkable areas to their people. Due to its importance, walkability has been a research topic in recent years. Vast empirical studies have reported evidence related to the influence of built environment on walking as a major physical activity. Considering the recent literature, this study developed a framework to quantify walkability by applying a set of indicators related to built environment. The indicators were normalised, weighted and integrated into an overall walkability index. The research was conducted on Chaharbagh Street, which is a major and ancient street in the Isfahan metropolitan area, Iran. The proposed framework would be helpful in investigations of whether a specific area is an appropriate option for a car-free plan based on its built environment features. The outcome of the study could be applied to understand issues related to pedestrian infrastructure and to propose corrective actions.
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ItemUndisturbed ground temperature in Melbourne(AIP Publishing, 2019-07-18)The ground surface temperature changes with the diurnal cycle of solar radiation and ambient air temperature. However, the amplitude of the ground temperature variation diminishes with the increase of the depth of the ground and after a certain depth of the ground, it becomes almost constant, where is termed "undisturbed ground temperature (UGT)". At this depth, the seasonal changes of solar radiation and ambient air temperature changes will no longer affect onground temperature. It is one of the important parameters for designing of the ground heat exchangers and building energy analyses. In this study ground temperatures at various depths in Melbourne were investigated using a 40 m deep borehole instrumented with thermistors. The ground temperatures at various depths (0 m to 40 m) in Melbourne were also simulated by using three methods: Kasuda formula method, simulation (TRNSYS, Type 77), and simplified correlation (developed by Ouzzane et al. in 2015) and the results were compared with the measured data. Root mean square error (RMSE) and mean bias error (MBE)were used to validate and verify the methods. It was found that the estimated ground temperatures at 2, 21, and 40 m depths by Kasuda formula method and simulation (TRNSYS)have the same trends as that of the measured data. The measured annual temperatures of ground at 2 m depth were between 14.7°C and 19.8°C, while the temperature at 21 m and 40 m depths remained almost constant. RMSE and MBE of the simulation (TRNSYS, Type 77) were found to be 1.39°C, and -1.39°C respectively compared to measured data at 21 m depth. Based on these values, we conclude that simulation (TRNSYS, Type 77) can reliably predict the ground temperature for the selected site in Melbourne.
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ItemEffective use of offsite manufacturing for public infrastructure projects in Australia(ICE Publishing, 2019)Prefabrication and offsite manufacturing have featured in various forms in an in-situ based construction industry for many decades. Scarcity of both human and material resources is challenging the future of traditional construction practices. Due to its many benefits such as speed of project delivery, minimum work on site, minimised construction waste and higher quality assurance, offsite manufacturing is gradually evolving into an essential technology in the construction industry. As a result of re-cent government initiatives, Australia is seeing a considerable increase in the use of offsite manufacturing and prefabricated modular technologies in delivering public infrastructure projects such as schools, healthcare facilities, and public transport facilities. Such projects are ably supported by academic research collaborating with the industry to ensure that the outcomes keep improving to achieve the highest quality and functionality. This paper discusses how multidisciplinary research addresses issues such as structural performance, construction technology, design for manufacturing and assembly and indoor environ-mental quality for the delivery of such public infrastructure projects. These projects have set an example in how offsite manufacturing supported by academic research can be beneficial for effectively delivering the greater good to the society.
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ItemEngaging employees with good sustainability: Key performance indicators for dry ports(MDPI AG, 2019-05-24)Dry ports have the potential to enhance the sustainability of transport systems, yet their introduction requires major changes to the current logistics chain. Further, emphasising sustainability goals and continued employee engagement can be a challenge when developing or implementing organisational change management programs in dry ports. Key considerations include governmental requirements and compliance, investor expectations, as well as employee engagement; these factors may be conflicting. The top-down management approach supported by strong leadership, participative approaches and constant communication assists in achieving successful change management. Sound selection of key performance indicators (KPIs) provides a set of metrics to track and aid the change process. They serve as a unifying link between top managements’ sustainability goals and employees’ engagement. The initial findings of our research confirm that both port and terminal operators have a gap in their understanding of the importance of sustainability goals and environmental goals. This will have a flow-on effect of port and terminal operators not driving the right messages to their staff in their organisational change management programs. Based on a critical literature review, it has been established what might qualify as good sustainability KPIs for dry ports. An example of a dry port at the Port of Somerton has been included. As every dry port has different requirements and constraints, it is important to develop KPIs together with stakeholders.
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ItemNo Preview AvailableA pilot study on users’ IEQ perceptions in a residential aged care facility in Melbourne(RMIT, 2018-11-29)The aged population in Australia is expanding rapidly. To cater for the Australia’s ageing population, there is a significant increase in demand for aged care facilities over the coming decades. The indoor environmental quality (IEQ) affects users’ physical health and psychological wellbeing. However, systematic research on the relationship between users’ perceptions and IEQ of aged care facilities has yet to be developed. In this pilot study, a residential aged care facility in Melbourne was selected as a case study for investigating the differences between the measured IEQ data and the users’ perceived individual comfort. A questionnaire survey was conducted to collect the perceptions of users on IEQ. Environmental sensors which enable web-based data monitoring were deployed. The measured data were then analysed together with the questionnaire survey results for drawing a comparison with the users’ perceptions. It was found that the measurements by environmental sensors are realistic and the survey questionnaires are appropriate for the study. For the future surveys, the language barrier needs to be considered for non-English speakers.
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ItemNo Preview AvailableSolar chilled drinking water sourced from thin air: Modelling and simulation of a solar powered atmospheric water generator(Modelling and Simulation Society of Australia and New Zealand, 2013-12-01)It is expected that there will be water scarcity in the future under the changing climate. Therefore investigations of innovative and environmentally friendly ways to produce portable water are very much essential. Atmospheric water generators (AWGs) apply vapour compression refrigeration to extract water vapour from the surrounding air. They produce drinking quality water and they require moist air and electricity. The required electricity may be produced by solar photovoltaic (PV) panels. By using solar energy the environmental impacts of an AWG associated with electricity consumption could be substantially reduced. The availability of solar energy and high humidity of air coincide with the drinking water demand. As of today the performance characteristics of stand-alone solar PV powered AWG is unknown. To address this knowledge gap a simulation model of such system has been developed. The model focuses on an individual phenomenon such as solar radiation availability, solar PV electricity output, battery storage, moisture content in the air and heat and mass transfer at the vapour compression refrigeration. The aim of this paper is to present the transient model developed and the simulation results. Kasaragod district in the state of Kerala, India is selected as the study area. Drinking water availability is a major issue in this district during the months from February to early June. Daily climate variables like temperature, maximum and minimum relative humidity, wind speed and global solar radiation on horizontal plane and wind speed were obtained from a meteorological station located in Kasaragod. A simulation model has been developed in TRNSYS with the following components: PV modules, Batteries, Regulator, Inverter and Atmospheric Water Generator. By using the model developed the capacity of the AWG, the number PV modules, the capacity of the battery bank required were determined for minimum daily water production of 15 L. The water extraction efficiency of the AWG investigated varies between 5.4% and 9.3% for Kasaragod. The cooling CCOPs of the AWG investigated are between 4 and 5, which is better than conventional air-to-air heat pump. Based on the analysis it was concluded that the monthly average daily efficiency is strongly correlated to the monthly average relative humidity of the ambient air. The monthly average daily efficiency is defined as average of all the daily average efficiency for a month. The validation of the simulation model with experiments to enable practical system design optimisations, and the development of control algorithms to obtain better performance by using the validated model are recommended for the future studies.
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ItemNo Preview AvailableINVESTIGATING POTENTIAL COMFORT BENEFITS OF BIOLOGICALLY-INSPIRED BUILDING SKINS(INT BUILDING PERFORMANCE SIMULATION ASSOC-IBPSA, 2013)