published_or_final_version / Transport Policy and Planning / Master / Master of Arts

published_or_final_version / Applied Geosciences / Master / Master of Science

While prior studies have examined the influence of environmental factors (e.g. regulatory, market, and socio-cultural environment) on construction safety accidents, the explanations offered remain piecemeal and the environmental factors are largely treated as given and immutable. In reality, the external environment is dynamic and continuously evolving. Contractors are subject to regulatory, market and socio-cultural segments of environment simultaneously. However, there has to date been little apparent effort to systematically investigate: 1) what are the pressures or expectations faced by contractors that operate in the broader context? And 2) how do contractors typically adapt to these pressures and expectations? Drawing on the institutional theory, this study aims to investigate how contractors experience and respond to the complex safety demands in their surrounding institutional environment. Institutional theory is borrowed because 1) the broad definition of institutions encompasses a wide range of environmental factors; and 2) it informs the mechanisms of how organisations are shaped by and strategically respond to institutional pressures. Given that the institutional theory in safety research is still nascent, lacking well-established constructs and casual relationships, a qualitative research strategy was employed, comprising three interlinked components: archival and documentary data analysis; case study; and semi-structured interviews. At the first step, the documentary and archival data analysis was conducted to establish a holistic view of the institutional environment faced by construction companies. Based on the documentary and archival data, this study developed a concept of construction safety-defined organisational field and provided a historical overview of the control and coordination mechanisms of the field. It is found that the field has undergone four stages: early days, the embryonic stage, golden time and the transition stage. An exploratory case study at the second step aimed at exploring whether site safety practices could be interpreted from an institutional theory perspective, and if it does, how? Safety practice data were obtained from 62 open-ended interviews and project archives. The institutional perspective was proved insightful in understanding contractors’ safety practices. The findings showed that the complex institutional environment, especially the incompatible progress and safety requirements, was a key determinant of mixed site safety practices. With the insights obtained from the documentary analysis and case study, semi-structured interviews were lastly carried out to investigate: 1) the specific institutional demands imposed on contractors regarding site safety; and 2) how contractors respond to the complex institutional demands. 24 semi-structured interviews were conducted. The data analysis follows the logic of abduction. By travelling back and forth between extant institutional theory literature and empirical evidence, the research findings were gradually formed. It is found that contractors face four categories of institutional demands comprising: 1) legislations and enforcement; 2) clients’ requirements; 3) construction companies’ internal requirements; and 4) field-level voluntary safety programmes. The results also showed that site safety is guided by two intertwining logics: the prescriptive logic and the performance-based logic. These two logics work collectively to improve site safety. Five patterns of institutional complexity were identified residing in the complex institutional environment. These are: 1) inconsistent regulatory demands; 2) regulatory uncertainty and rigidity; 3) redundant institutional demands from field actors; 4) conflict between safety demands and production efficiency; and 5) disparate values and beliefs about safety and the ways to achieve safety. Contractor’s experience of institutional pressures and general safety management strategies depend on construction companies’ field positions (i.e., central and peripheral). The level of institutional complexity experienced by contractors is moderated by project structure and governance. It is found that contractors would adopt a series of strategic responses, such as concealment, buffering, imitation and influence, to cope with those five patterns of institutional complexity. This study extends the existing safety research to an institutional domain. The organisational field perspective adds a new dimension to explain safety management actions or structures of construction companies. Practical implications are also provided for policy-makers, clients and construction companies. / published_or_final_version / Real Estate and Construction / Doctoral / Doctor of Philosophy

This study presents an analytical approach for the mechanics of the pneumatic tires and the vehicle dynamic simulation. Most of tire dynamic parameters in this study are derived by using the tire geometry rather than experimental data. For the tire dynamic properties, explicit formulations are derived analytically as functions of slip ratio, slip angle, camber angle, and other tire dynamic parameters. These formulations can be efficiently used for the general vehicle simulations of braking/traction and steering maneuvers with a varying camber angle at irregular terrains. For on-highway vehicle simulations, a conceptual sports car is modeled as a twenty-six degrees of freedom multi-body system, while the military 1/4 ton truck M151-A2 is modeled as a fourteen degrees of freedom multi-body system for off-highway vehicle simulations. To study vehicle ride comfort, stability, and maneuverability, numerous vehicle simulations are performed using the comprehensive tire model, steering, braking, traction, nonlinear suspension, and realistic irregular terrains. For these simulations, a general-purpose multi-body dynamic analysis code (named MBOSS) has been developed.

Naval Aviation has been known for over half a century as being one of the most fascinating professions. Although aircrew may always play a role in the mishap rate, the Navy has shifted its focus to aviation maintenance safety climate as a possible indicator of a future mishap. The School of Aviation Safety developed and implemented a survey, the Maintenance Climate Assessment Survey (MCAS), to assess the safety climate of Naval Aviation squadrons. Researchers have begun reviewing the possible direct relationship between the maintainer, how they view their squadron's climate and aviation mishaps. This thesis examines the construct of squadron maintenance safety climate survey and its relationship to aviation mishaps. The raw data employed includes MCAS responses from 126,058 maintainers between August 2000 and August 2005. This study finds that the MCAS survey construction needs to be revised. The findings are substantial to verify that most questions are formulated to focus on the same factor. Since the survey requires reconstruction, the question of whether it can determine the likelihood of mishaps was never visited. Revising the survey, based on psychometrics, may produce more significant results and gauge maintenance safety climate based on separate and distinct factors.

Digitized by Kansas Correctional Industries

Digitized by Kansas Correctional Industries

Digitized by Kansas Correctional Industries

Many types of foods are sterilised and packaged aseptically to maximise their shelf life and ensure that they are safe for consumption. However, if even a few micro-organisms survive these treatments, the quality and/or safety of the food can be seriously compromised. Therefore, packaging materials that can actively participate in the process of inactivating micro-organisms have a potentially important role in protecting the quality and safety of packaged foods. The aim of this project is to explore the effectiveness of the photodynamic effect as a method of inactivating micro-organisms on the surface of packaging materials. Photodynamic action occurs when a photosensitiser molecule absorbs light in the presence of oxygen, leading to the formation of reactive oxygen species such as singlet oxygen, superoxide radicals, or other free radicals; these species are known to inactivate cells. Medical uses of photodynamic action have been studied extensively, usually in applications where the reactive oxygen species are produced intracellularly. However, very little research has been conducted to investigate the efficacy of extra-cellularly generated reactive oxygen species on the viability of micro-organisms, and accordingly this research project investigated the possibility that this approach might be used for inactivating micro-organisms on packaging materials. The results of this study indicate that singlet oxygen may be produced at the surface of polymer films that contain selected photosensitisers, resulting in the oxidation of known singlet-oxygen acceptors to form endoperoxides. This provides evidence that singlet-oxygen mediated reactions can occur at the surface of a sensitising film. It is likely that cell destruction is caused by singlet-oxygen, rather than involving other activated species. It was further shown that the photodynamically generated singlet-oxygen can inactivate micro-organisms (extra-cellularly) on the surface of a polymeric material. The study included examples from each genus of micro-organisms that are of concern to the food and packaging industry, including: Gram-negative bacteria (Escherichia coli); Gram-positive bacteria (Bacillus cereus), both vegetative cells and endospores; yeast (Saccharomyces cerevisiae), and mould (Fusarium oxysporium.) Results indicate that the photodynamic effect causes a substantial reduction in viable cell numbers for vegetative cells and spores (both bacterial and fungal) that have been inoculated onto a plastic surface containing the photosensitiser, anthraquinone,. The results show that an increase in the amount of reactive oxygen species produced by photodynamic action increases the inactivation rate of the micro-organisms. The micro-organisms investigated were susceptible to photodynamic action to varying extents. In conclusion, the results demonstrate that control of microbial populations on the surface of polymeric films (used in food packaging) is achievable using photodynamic action produced from polymers, based on the reported amounts of micro-organisms found on food packaging materials. / Master of Science (Hons)

In this thesis, the author has drawn on a large body of international research and his own surveys, interviews and experience to examine the interrelated issues of Fatigue and Stress in the long distance sector of the Australian road transport industry. Two major Australian studies are studied in some detail: House of Representatives Standing Committee on Communications, Transport and the Arts: Beyond the Midnight Oil, Report into an Inquiry into Managing Fatigue in Transport, Parliament of the Commonwealth of Australia October 2000 (The Neville Report) and Quinlan, Michael, Report of an Inquiry into Safety in the Long Haul Sector of the Road Trucking Industry, Motor Accident Authority of NSW, Nov 2001 and the United States of America: Belzer, Michael H., Sweatshop on Wheels: Winners and Losers in Trucking Deregulation, Oxford University Press, New York, 2000, has direct relevance to this study, especially as it relates to the underlying causes of much of the fatigue and stress suffered by long distance drivers. An extensive literature review was undertaken to help form an understanding of the issues and developments relating to workplace fatigue and stress, in several different settings, including the military, aviation and general industry. The author has surveyed a number of long distance drivers and interviewed managers and others linked to this industry, analysed their responses and reported on the findings. Since the commencement of this study, several significant changes have occurred in the relevant legislation and its application, and where possible these have been incorporated into the study / Master of Science (Hons)