Speech interference on residential balconies with road traffic noise

Residential balcony design influences speech interference levels caused by road traffic noise and a simplified design methodology is needed for optimising balcony acoustic treatments. This research comprehensively assesses speech interference levels and benefits of nine different balcony designs situated in urban street canyons through the use of a combined direct, specular reflection and diffuse reflection path theoretical model. This thesis outlines the theory, analysis and results that lead up to the presentation of a practical design guide which can be used to predict the acoustic effects of balcony geometry and acoustic treatments in streets with variable geometry and acoustic characteristics.

Lifecycle costs of ultracapacitors in electric vehicle applications

The pulse power characteristics of ultracapacitors appear well suited to electric vehicle applications, where they may supply the peak power more efficiently than the battery, and can prevent excessive over sizing of the battery pack due to peak power demands. Operation of ultracapacitors in battery electric vehicles is examined for possible improvements in system efficiency, vehicle driving range, battery pack lifetime, and potential reductions in system lifecycle cost. The lifecycle operation of these ultracapacitors is simulated using custom-built, dynamic simulation code constructed in Matlab. Despite apparent gains in system efficiency and driving range, the results strongly suggest that the inclusion of ultracapacitors in the electric vehicle does not make sense from a lifecycle cost perspective. Furthermore, a comparison with results from earlier work shows that this outcome is highly dependant upon the efficiency and cost of the battery under consideration. However, it is likely that the lifecycle cost benefits of ultracapacitors in these electric vehicles would be, at most, marginal and do not justify the additional capital costs and system complexity that would be incurred in the vehicle

Simulated lifecycle costs of ultracapacitors in battery electric vehicles

The pulse power characteristics of ultracapacitors appear well suited to electric vehicle applications, where they may supply the peak power more efficiently than the battery, and can prevent excessive over sizing of the battery pack due to peak power demands. Operation of ultracapacitors in battery electric vehicles (BEVs) is examined for possible improvements in system efficiency, vehicle driving range, battery pack lifetime, and potential reductions in system lifecycle cost. The lifecycle operation of these ultracapacitors is simulated using a custom-built, dynamic simulation code constructed in Matlab. Despite apparent gains in system efficiency and driving range, the lifecycle cost benefits as simulated appear to be marginal, and are heavily influenced by the incremental cost of power components. However, additional factors are identified which, in reality, will drive ultracapacitors towards viability in electric vehicle applications.

Decision making guidelines for sustainable construction of industrialised building systems

The construction industry has an obligation to respond to sustainability expectations of our society. Solutions that integrate innovative, intelligent and sustainability deliverables are vital for us to meet new and emerging challenges. Industrialised Building Systems (IBS), or known otherwise as prefabrication, employs a combination of ready-made components in the construction of buildings. They promote quality of production, enhance simplification of construction processes and minimise waste. The unique characteristics of this construction method respond well to sustainability. Despite the promises however, IBS has yet to be effectively implemented in Malaysia. There are often misconceptions among key stakeholders about IBS applications. The existing rating schemes fail to assess IBS against sustainability measures. To ensure the capture of full sustainability potential in buildings developed, the critical factors and action plans agreeable to all participants in the development processes need to be identified. Through questionnaire survey, eighteen critical factors relevant to IBS sustainability were identified and encapsulated into a conceptual framework to coordinate a systematic IBS decision making approach. Five categories were used to separate the critical factors into: ecological performance; economic value; social equity and culture; technical quality; and implementation and enforcement. This categorisation extends the "Triple Bottom Lines" to include social, economic, environmental and institutional dimensions. Semi-structured interviews help identify strategies of actions and solutions of potential problems through a SWOT analysis framework. These tools help the decision-makers maximise the opportunities by using available strengths, avoid weaknesses, and diagnose possible threats in the examined issues. The recommendations formed an integrated action plan to present information on what and how to improve sustainability through tackling each critical factor during IBS development. It can be used as part of the project briefing documents for IBS designers. For validation and finalisation the research deliverables, three case studies were conducted. The research fills a current gap by responding to IBS project scenarios in developing countries. It also provides a balanced view for designers to better understand sustainability potential and prioritize attentions to manage sustainability issues in IBS applications.

First flush behaviour in urban residential catchments

The current state of knowledge in relation to first flush does not provide a clear understanding of the role of rainfall and catchment characteristics in influencing this phenomenon. This is attributed to the inconsistent findings from research studies due to the unsatisfactory selection of first flush indicators and how first flush is defined. The research study discussed in this thesis provides the outcomes of a comprehensive analysis on the influence of rainfall and catchment characteristics on first flush behaviour in residential catchments. Two sets of first flush indicators are introduced in this study. These indicators were selected such that they are representative in explaining in a systematic manner the characteristics associated with first flush. Stormwater samples and rainfall-runoff data were collected and recorded from stormwater monitoring stations established at three urban catchments at Coomera Waters, Gold Coast, Australia. In addition, historical data were also used to support the data analysis. Three water quality parameters were analysed, namely, total suspended solids (TSS), total phosphorus (TP) and total nitrogen (TN). The data analyses were primarily undertaken using multi criteria decision making methods, PROMETHEE and GAIA. Based on the data obtained, the pollutant load distribution curve (LV) was determined for the individual rainfall events and pollutant types. Accordingly, two sets of first flush indicators were derived from the curve, namely, cumulative load wash-off for every 10% of runoff volume interval (interval first flush indicators or LV) from the beginning of the event and the actual pollutant load wash-off during a 10% increment in runoff volume (section first flush indicators or P). First flush behaviour showed significant variation with pollutant types. TSS and TP showed consistent first flush behaviour. However, the dissolved fraction of TN showed significant differences to TSS and TP first flush while particulate TN showed similarities. Wash-off of TSS, TP and particulate TN during the first 10% of the runoff volume showed no influence from corresponding rainfall intensity. This was attributed to the wash-off of weakly adhered solids on the catchment surface referred to as "short term pollutants" or "weakly adhered solids" load. However, wash-off after 10% of the runoff volume showed dependency on the rainfall intensity. This is attributed to the wash-off of strongly adhered solids being exposed when the weakly adhered solids diminish. The wash-off process was also found to depend on rainfall depth at the end part of the event as the strongly adhered solids are loosened due to impact of rainfall in the earlier part of the event. Events with high intensity rainfall bursts after 70% of the runoff volume did not demonstrate first flush behaviour. This suggests that rainfall pattern plays a critical role in the occurrence of first flush. Rainfall intensity (with respect to the rest of the event) that produces 10% to 20% runoff volume play an important role in defining the magnitude of the first flush. Events can demonstrate high magnitude first flush when the rainfall intensity occurring between 10% and 20% of the runoff volume is comparatively high while low rainfall intensities during this period produces low magnitude first flush. For events with first flush, the phenomenon is clearly visible up to 40% of the runoff volume. This contradicts the common definition that first flush only exists, if for example, 80% of the pollutant mass is transported in the first 30% of runoff volume. First flush behaviour for TN is different compared to TSS and TP. Apart from rainfall characteristics, the composition and the availability of TN on the catchment also play an important role in first flush. The analysis confirmed that events with low rainfall intensity can produce high magnitude first flush for the dissolved fraction of TN, while high rainfall intensity produce low dissolved TN first flush. This is attributed to the source limiting behaviour of dissolved TN wash-off where there is high wash-off during the initial part of a rainfall event irrespective of the intensity. However, for particulate TN, the influence of rainfall intensity on first flush characteristics is similar to TSS and TP. The data analysis also confirmed that first flush can occur as high magnitude first flush, low magnitude first flush or non existence of first flush. Investigation of the influence of catchment characteristics on first flush found that the key factors that influence the phenomenon are the location of the pollutant source, spatial distribution of the pervious and impervious surfaces in the catchment, drainage network layout and slope of the catchment. This confirms that first flush phenomenon cannot be evaluated based on a single or a limited set of parameters as a number of catchment characteristics should be taken into account. Catchments where the pollutant source is located close to the outlet, a high fraction of road surfaces, short travel time to the outlet, with steep slopes can produce high wash-off load during the first 50% of the runoff volume. Rainfall characteristics have a comparatively dominant impact on the wash-off process compared to the catchment characteristics. In addition, the pollutant characteristics also should be taken into account in designing stormwater treatment systems due to different wash-off behaviour. Analysis outcomes confirmed that there is a high TSS load during the first 20% of the runoff volume followed by TN which can extend up to 30% of the runoff volume. In contrast, high TP load can exist during the initial and at the end part of a rainfall event. This is related to the composition of TP available for the wash-off.

Of dogs, fish, birds and turds : the social construction of sewage pollution by recreational boaters

Animals are often used as ‘evidence’ of marine pollution. Take for instance the ubiquitous images of miserable oil-soaked marine birds following high profile oil spills such as the Exxon Valdez, Pacific Adventurer and Deepwater Horizon incidents or the images of bloated floating fish carcasses which are used to signal the presence of toxic pollutants. In recent years waste discharges from vessels have come under increased public and regulatory scrutiny both in Australia and around the world. International, regional, national and local restrictions are becoming more stringent for high profile marine pollutants such as oil as well as previously overlooked vessel-sourced pollutants such as sewage. Drawing upon media reports and recreational boater responses to government attempts to regulate the discharge of sewage from recreational vessels, this paper considers the important role played by animals in constructions of marine pollution by sewage and attributions of blame for this pollution. Specifically, this study found that recreational boat owners disputed claims their sewage management practices posed an environmental threat arguing that the sewage discharged was readily and eagerly consumed by fish in the receiving environment. Boat owners also argued that increased levels of bacteria which indicate the presence of faeces within the marine environment could be directly attributed to the excrement of marine mammals and birds or were the result of dog faeces being washed through municipal storm water systems rather than the result of vessel discharges. By contrast the contamination of oysters was provided as evidence of sewage pollution by other stakeholders.

An examination of the independent certification processes of a construction contract

Construction contracts often provide that the decision of an independent certifier is final and binding. The effect of a contractual term like this has been debated in the courts over time. This paper considers the binding nature of certificates in the context of traditional construction contract arrangements and also considers the implications for more complex contracts like those entered into to facilitate public private partnerships. This article considers the response of the courts and the drafting implications and argues that a different focus would be advantageous.

Knowledge inquiry in the construction management domain through structured research process and methodology

Construction works are project-based and interdisciplinary. Many construction management (CM) problems are ill defined. The knowledge required to address such problems is not readily available and mostly tacit in nature. Moreover, the researchers, especially the students in the higher education, often face difficulty in defining the research problem, adopting an appropriate research process and methodology for designing and validating their research. This paper describes a ‘Horseshoe’ research process approach and its application to address a research problem of extracting construction-relevant information from a building information model (BIM). It describes the different steps of the process for understanding a problem, formulating appropriate research question/s, defining different research tasks, including a methodology for developing, implementing and validating the research. It is argued that a structure research approach and the use of mixed research methods would provide a sound basis for research design and validation in order to make contribution to existing knowledge.

The health outcomes and costs of people attending an interdisciplinary chronic disease service in regional Australia : protocol for a longitudinal cohort investigation

Background Rates of chronic disease are escalating around the world. To date health service evaluations have focused on interventions for single chronic diseases. However, evaluations of the effectiveness of new intervention strategies that target single chronic diseases as well as multimorbidity are required, particularly in areas outside major metropolitan centres where access to services, such as specialist care, is difficult and where the retention and recruitment of health professionals affects service provision. Methods This study is a longitudinal investigation with a baseline and three follow-up assessments comparing the health and health costs of people with chronic disease before and after intervention at a chronic disease clinic, in regional Australia. The clinic is led by students under the supervision of health professionals. The study will provide preliminary evidence regarding the effectiveness of the intervention, and evaluate the influence of a range of factors on the health outcomes and costs of the patients attending the clinic. Patients will be evaluated at baseline (intake to the service), and at 3-, 6-, and 12-months after intake to the service. Health will be measured using the SF-36 and health costs will be measured using government and medical record sources. The intervention involves students and health professionals from multiple professions working together to treat patients with programs that include education and exercise therapy programs for back pain, and Healthy Lifestyle programs; as well as individual consultations involving single professions. Discussion Understanding the effect of a range of factors on the health state and health costs of people attending an interdisciplinary clinic will inform health service provision for this clinical group and will determine which factors need to be controlled for in future observational studies. Preliminary evidence regarding changes in health and health costs associated with the intervention will be a platform for future clinical trials of intervention effectiveness. The results will be of interest to teams investigating new chronic disease programs particularly for people with multimorbidity, and in areas outside major metropolitan centres.

Engineering based problem solving in the middle school : design and construction with simple machines

Incorporating engineering concepts into middle school curriculum is seen as an effective way to improve students’ problem-solving skills. A selection of findings is reported from a science, technology, engineering and mathematics (STEM)-based unit in which students in the second year (grade 8) of a three-year longitudinal study explored engineering concepts and principles pertaining to the functioning of simple machines. The culminating activity, the focus of this paper, required the students to design, construct, test, and evaluate a trebuchet catapult. We consider findings from one of the schools, a co-educational school, where we traced the design process developments of four student groups from two classes. The students’ descriptions and explanations of the simple machines used in their catapult design are examined, together with how they rated various aspects of their engineering designs. Included in the findings are students’ understanding of how their simple machines were simulated by the resources supplied and how the machines interacted in forming a complex machine. An ability to link physical materials with abstract concepts and an awareness of design constraints on their constructions were apparent, although a desire to create a ‘‘perfect’’ catapult despite limitations in the physical materials rather than a prototype for testing concepts was evident. Feedback from teacher interviews added further insights into the students’ developments as well as the teachers’ professional learning. An evolving framework for introducing engineering education in the pre-secondary years is proposed.

The construction of social identity in new nuclear operators : a longitudinal study

Countless studies have stressed the importance of social identity, particularly its role in various organizational outcomes, yet questions remain as to how identities initially develop, shift and change based on the configuration of multiple, pluralistic relationships grounded in an organizational setting. The interactive model of social identity formation has been proposed recently to explain the internalization of shared norms and values – critical in identity formation – has not received empirical examination. We analyzed multiple sources of data from nine nuclear professionals over three years to understand the construction of social identity in new entrants entering an organization. Informed by our data analyses, we found support for the interactive model and that age and level of experience influenced whether they undertook an inductive or deductive route of the group norm and value internalization. This study represents an important contribution to the study of social identity and the process by which identities are formed, particularly under conditions of duress or significant organizational disruption.

Green skills for the construction industry

The skill shortage issues have long existed in the construction industry in countries like Australia. Couple this with the lead and lag time between market demand and resultant supply has traditionally seen cyclical fluctuation of skills demand within the construction industry. Skills demand and shortages are generally well documented and can even have a level of predictability in Australia given the tendency to have a delayed reaction to global economic downturns. Sustainability issues in the construction industry have attracted growing public awareness. Traditionally driven by ever increasing, if only gradual, mandated minimum requirements, drive towards sustainable developments is now increasingly being created by the client. As this demand increases, accordingly a demand for people with the skills to provide these services should be felt. This research examines the green skill shortage issues within the context of construction industry. Stakeholders from across relevant sectors of the built environment were engaged to ascertain the industry’s utilisation and demand for ‘green skilled’ personnel. These findings will assist stakeholders within the construction industry in negating the effects of a skills shortage in the event of accelerated demand for sustainable construction.

Risk compensation in construction workers' activities

Construction has been plagued with serious injuries and deaths for years. Although the technological advances have made the world safer and healthier, researchers have noted that some safety interventions, which had clear objective safety benefits, had failed to achieve the forecast savings in lives and injuries. The purpose of this study was to explore whether the construction workers show risk compensation and engage in greater risk taking when certain types of safety measures are implemented in the construction site. A case study approach was used to achieve the aim of this study. A typical construction site in Sydney was selected as the subject of the case study. Data were collected through direct observations, questionnaires and interviews. The findings confirm that workers show risk compensation behaviours in the construction environment. The risk compensation behaviours of workers varied with the level of experience and whether they have suffered from a past workplace injury. The findings of this study may offer a better understanding of workers’ behavioural patterns in construction environment and the effectiveness of safety interventions. The result of this study may provide supports for designing, implementing and evaluating safety interventions in construction site.