Heavy vehicle suspensions : testing and analysis

Transport regulators consider that, with respect to pavement damage, heavy vehicles (HVs) are the riskiest vehicles on the road network. That HV suspension design contributes to road and bridge damage has been recognised for some decades. This thesis deals with some aspects of HV suspension characteristics, particularly (but not exclusively) air suspensions. This is in the areas of developing low-cost in-service heavy vehicle (HV) suspension testing, the effects of larger-than-industry-standard longitudinal air lines and the characteristics of on-board mass (OBM) systems for HVs. All these areas, whilst seemingly disparate, seek to inform the management of HVs, reduce of their impact on the network asset and/or provide a measurement mechanism for worn HV suspensions. A number of project management groups at the State and National level in Australia have been, and will be, presented with the results of the project that resulted in this thesis. This should serve to inform their activities applicable to this research. A number of HVs were tested for various characteristics. These tests were used to form a number of conclusions about HV suspension behaviours. Wheel forces from road test data were analysed. A “novel roughness” measure was developed and applied to the road test data to determine dynamic load sharing, amongst other research outcomes. Further, it was proposed that this approach could inform future development of pavement models incorporating roughness and peak wheel forces. Left/right variations in wheel forces and wheel force variations for different speeds were also presented. This led on to some conclusions regarding suspension and wheel force frequencies, their transmission to the pavement and repetitive wheel loads in the spatial domain. An improved method of determining dynamic load sharing was developed and presented. It used the correlation coefficient between two elements of a HV to determine dynamic load sharing. This was validated against a mature dynamic loadsharing metric, the dynamic load sharing coefficient (de Pont, 1997). This was the first time that the technique of measuring correlation between elements on a HV has been used for a test case vs. a control case for two different sized air lines. That dynamic load sharing was improved at the air springs was shown for the test case of the large longitudinal air lines. The statistically significant improvement in dynamic load sharing at the air springs from larger longitudinal air lines varied from approximately 30 percent to 80 percent. Dynamic load sharing at the wheels was improved only for low air line flow events for the test case of larger longitudinal air lines. Statistically significant improvements to some suspension metrics across the range of test speeds and “novel roughness” values were evident from the use of larger longitudinal air lines, but these were not uniform. Of note were improvements to suspension metrics involving peak dynamic forces ranging from below the error margin to approximately 24 percent. Abstract models of HV suspensions were developed from the results of some of the tests. Those models were used to propose further development of, and future directions of research into, further gains in HV dynamic load sharing. This was from alterations to currently available damping characteristics combined with implementation of large longitudinal air lines. In-service testing of HV suspensions was found to be possible within a documented range from below the error margin to an error of approximately 16 percent. These results were in comparison with either the manufacturer’s certified data or test results replicating the Australian standard for “road-friendly” HV suspensions, Vehicle Standards Bulletin 11. OBM accuracy testing and development of tamper evidence from OBM data were detailed for over 2000 individual data points across twelve test and control OBM systems from eight suppliers installed on eleven HVs. The results indicated that 95 percent of contemporary OBM systems available in Australia are accurate to +/- 500 kg. The total variation in OBM linearity, after three outliers in the data were removed, was 0.5 percent. A tamper indicator and other OBM metrics that could be used by jurisdictions to determine tamper events were developed and documented. That OBM systems could be used as one vector for in-service testing of HV suspensions was one of a number of synergies between the seemingly disparate streams of this project.

Development and evaluation of hydrocarbon sorbent materials with the aid of chemometrics

Hydrocarbon spills on roads are a major safety concern for the driving public and can have severe cost impacts both on pavement maintenance and to the economy through disruption to services. The time taken to clean-up spills and re-open roads in a safe driving condition is an issue of increasing concern given traffic levels on major urban arterials. Thus, the primary aim of the research was to develop a sorbent material that facilitates rapid clean-up of road spills. The methodology involved extensive research into a range of materials (organic, inorganic and synthetic sorbents), comprehensive testing in the laboratory, scale-up and field, and product design (i.e. concept to prototype). The study also applied chemometrics to provide consistent, comparative methods of sorbent evaluation and performance. In addition, sorbent materials at every stage were compared against a commercial benchmark. For the first time, the impact of diesel on asphalt pavement has been quantified and assessed in a systematic way. Contrary to conventional thinking and anecdotal observations, the study determined that the action of diesel on asphalt was quite rapid (i.e. hours rather than weeks or months). This significant finding demonstrates the need to minimise the impact of hydrocarbon spills and the potential application of the sorbent option. To better understand the adsorption phenomenon, surface characterisation techniques were applied to selected sorbent materials (i.e. sand, organo-clay and cotton fibre). Brunauer Emmett Teller (BET) and thermal analysis indicated that the main adsorption mechanism for the sorbents occurred on the external surface of the material in the diffusion region (sand and organo-clay) and/or capillaries (cotton fibre). Using environmental scanning electron microscopy (ESEM), it was observed that adsorption by the interfibre capillaries contributed to the high uptake of hydrocarbons by the cotton fibre. Understanding the adsorption mechanism for these sorbents provided some guidance and scientific basis for the selection of materials. The study determined that non-woven cotton mats were ideal sorbent materials for clean-up of hydrocarbon spills. The prototype sorbent was found to perform significantly better than the commercial benchmark, displaying the following key properties: • superior hydrocarbon pick-up from the road pavement; • high hydrocarbon retention capacity under an applied load; • adequate field skid resistance post treatment; • functional and easy to use in the field (e.g. routine handling, transportation, application and recovery); • relatively inexpensive to produce due to the use of raw cotton fibre and simple production process; • environmentally friendly (e.g. renewable materials, non-toxic to environment and operators, and biodegradable); and • rapid response time (e.g. two minutes total clean-up time compared with thirty minutes for reference sorbents). The major outcomes of the research project include: a) development of a specifically designed sorbent material suitable for cleaning up hydrocarbon spills on roads; b) submission of patent application (serial number AU2005905850) for the prototype product; and c) preparation of Commercialisation Strategy to advance the sorbent product to the next phase (i.e. R&D to product commercialisation).

Publishing Engineering Education Resources: A Collaborative Web Project.

Web is a powerful hypermedia-based information retrieval mechanism that provides a user-friendly access across all major computer platforms connected over Internet. This paper demonstrates the application of Web technology when used as an educational delivery tool. It also reports on the development of a prototype electronic publishing project where Web technology was used to deliver power engineering educational resources. The resulting hyperbook will contain diverse teaching resources such as hypermedia-based modular educational units and computer simulation programs that are linked in a meaningful and structured way. The use of Web for disseminating information of this nature has many advantages that cannot possibly be achieved otherwise. PREAMBLE The continual increase of low-cost functionality available in desktop computing has opened up a new possibility in learning within a wider educational framework. This technology also is supported by enhanced features offered by new and ...

Androgen-regulated genes differentially modulated by the androgen receptor coactivator L-dopa decarboxylase in human prostate cancer cells

Background The androgen receptor is a ligand-induced transcriptional factor, which plays an important role in normal development of the prostate as well as in the progression of prostate cancer to a hormone refractory state. We previously reported the identification of a novel AR coactivator protein, L-dopa decarboxylase (DDC), which can act at the cytoplasmic level to enhance AR activity. We have also shown that DDC is a neuroendocrine (NE) marker of prostate cancer and that its expression is increased after hormone-ablation therapy and progression to androgen independence. In the present study, we generated tetracycline-inducible LNCaP-DDC prostate cancer stable cells to identify DDC downstream target genes by oligonucleotide microarray analysis. Results Comparison of induced DDC overexpressing cells versus non-induced control cell lines revealed a number of changes in the expression of androgen-regulated transcripts encoding proteins with a variety of molecular functions, including signal transduction, binding and catalytic activities. There were a total of 35 differentially expressed genes, 25 up-regulated and 10 down-regulated, in the DDC overexpressing cell line. In particular, we found a well-known androgen induced gene, TMEPAI, which wasup-regulated in DDC overexpressing cells, supporting its known co-activation function. In addition, DDC also further augmented the transcriptional repression function of AR for a subset of androgen-repressed genes. Changes in cellular gene transcription detected by microarray analysis were confirmed for selected genes by quantitative real-time RT-PCR. Conclusion Taken together, our results provide evidence for linking DDC action with AR signaling, which may be important for orchestrating molecular changes responsible for prostate cancer progression.

Didiman: Australian agricultural extension officers in the territory of Papua and New Guinea, 1945-1975

Historically, the development philosophy for the two Territories of Papua and New Guinea (known as TPNG, formerly two territories, Papua and New Guinea) was equated with economic development, with a focus on agricultural development. To achieve the modification or complete change in indigenous farming systems the Australian Government’s Department of External Territories adopted and utilised a programme based on agricultural extension. Prior to World War II, under Australian administration, the economic development of these two territories, as in many colonies of the time, was based on the institution of the plantation. Little was initiated in agriculture development for indigenous people. This changed after World War II to a rationale based on the promotion and advancement of primary industry, but also came to include indigenous farmers. To develop agriculture within a colony it was thought that a modification to, or in some cases the complete transformation of, existing farming systems was necessary to improve the material welfare of the population. It was also seen to be a guarantee for the future national interest of the sovereign state after independence was granted. The Didiman and Didimisis became the frontline, field operatives of this theoretical model of development. This thesis examines the Didiman’s field operations, the structural organisation of agricultural administration and the application of policy in the two territories.

Faculty and employee ownership of inventions in Australia

A recent decision by the Australian High Court means that, unless faculty are bound by an assignment or intellectual property (IP) policy, they may own inventions resulting from their research. Thirty years after its introduction, the US Bayh-Dole Act, which vests ownership of employee inventions in the employer university or research organization, has become a model for commercialization around the world. In Australia, despite recommendations that a Bayh-Dole style regime be adopted, the recent decision in University of Western Australia (UWA) v Gray1 has moved the default legal position in a diametrically opposite direction. A key focus of the debate was whether faculty’s duty to carry out research also encompasses a duty to invent. Late last year, the Full Federal Court confirmed a lower court ruling that it does not, and this year the High Court refused leave to appeal (denied certiorari). Thus, Gray stands as Australia’s most faculty-friendly authority to date.

Measuring costs of sustainability issues in highway infrastructure : perception of stakeholders in Australia

With increasing pressure to deliver environmentally friendly and socially responsible highway infrastructure projects, stakeholders are also putting significant focus on the early identification of financial viability and outcomes for these projects. Infrastructure development typically requires major capital input, which may cause serious financial constraints for investors. The push for sustainability has added new dimensions to the evaluation of highway projects, particularly on the cost front. Comprehensive analysis of the cost implications of implementing place sustainable measures in highway infrastructure throughout its lifespan is highly desirable and will become an essential part of the highway development process and a primary concern for decision makers. This paper discusses an ongoing research which seeks to identify cost elements and issues related to sustainable measures for highway infrastructure projects. Through life-cycle costing analysis (LCCA), financial implications of pursuing sustainability, which are highly concerned by the construction stakeholders, have been assessed to aid the decision making when contemplating the design, development and operation of highway infrastructure. An extensive literature review and evaluation of project reports from previous Australian highway projects was first conducted to reveal all potential cost elements. This provided the foundation for a questionnaire survey, which helped identify those specific issues and related costs that project stakeholders consider to be most critical in the Australian industry context. Through the survey, three key stakeholders in highway infrastructure development, namely consultants, contractors and government agencies, provided their views on the specific selection and priority ranking of the various categories. Findings of the survey are being integrated into proven LCCA models for further enhancement. A new LCCA model will be developed to assist the stakeholders to evaluate costs and investment decisions and reach optimum balance between financial viability and sustainability deliverables.

The role of the audit committee and institutional investors in constraining earnings management : evidence from Chinese firms listed in Hong Kong

Using data from 2004 to 2008, we find that an audit committee is an important monitoring mechanism as audit committee independence, expertise and size are associated with reduced levels of abnormal accruals, our measure of earnings management. This study also attempts to discern when the monitoring role of the audit committee is more salient for the firm. We find that ownership concentration and the presence of government officials on the audit committee are important determinants of the negative association between audit committee characteristics and earnings management. In contrast, we find no significant associations between the audit committee and abnormal accruals for Chinese firms listed only on the Chinese domestic Stock Exchanges. The paper contributes to the corporate governance literature in a transitional economy. Identifying the role of audit committees of firms listed on markets other than the domicile market demonstrates the importance of considering the institutional setting in governance research.

Can an effective audit committee help to mitigate earnings management in Chinese firms listed in Hong Kong?

This paper attempts to determine whether the adoption of recommended corporate governance practices by Chinese firms is associated with less earnings management proxied by abnormal accruals. We examine the role of the audit committee and ownership concentration in preventing earnings management using Chinese firms listed in Hong Kong. The results of this preliminary analysis show that the frequency of audit committee meetings is associated with reduced levels of abnormal accruals, our measure of earnings management. We conclude that audit committee activity is an important factor in constraining the propensity of managers to engage in earnings management. In contrast, we find that the size of the audit committee is associated with increased levels of abnormal accruals and suggest that increasing the size of the audit committee creates information asymmetry between the audit committee and management that reduces the monitoring capacity of the audit committee. We do not find any association between audit committee independence, financial and industry experience, or ownership concentration and abnormal accruals.

Bayesian multinomial logit: Theory and route choice example

Statisticians along with other scientists have made significant computational advances that enable the estimation of formerly complex statistical models. The Bayesian inference framework combined with Markov chain Monte Carlo estimation methods such as the Gibbs sampler enable the estimation of discrete choice models such as the multinomial logit (MNL) model. MNL models are frequently applied in transportation research to model choice outcomes such as mode, destination, or route choices or to model categorical outcomes such as crash outcomes. Recent developments allow for the modification of the potentially limiting assumptions of MNL such as the independence from irrelevant alternatives (IIA) property. However, relatively little transportation-related research has focused on Bayesian MNL models, the tractability of which is of great value to researchers and practitioners alike. This paper addresses MNL model specification issues in the Bayesian framework, such as the value of including prior information on parameters, allowing for nonlinear covariate effects, and extensions to random parameter models, so changing the usual limiting IIA assumption. This paper also provides an example that demonstrates, using route-choice data, the considerable potential of the Bayesian MNL approach with many transportation applications. This paper then concludes with a discussion of the pros and cons of this Bayesian approach and identifies when its application is worthwhile

Gender inequality and the spread of HIV-AIDS in India

Purpose The purpose of the paper is to analyze the low status of women as being a major contributor for the observed gender inequality in the spread of HIV/AIDS in India. Design/methodology/approach The paper uses data from National Aids Control Organization (NACO), National Family Health Survey (NFHS 3), and the Directorate of Economics and Statistics. Findings This study highlights the problems facing women in deterring the spread of HIV/AIDS in India. The status and empowerment of women are important variables in combating the disease among both men and women in India. Literacy, education, exposure to the media, labor market participation, awareness of HIV/AIDS, and economic independence are important considerations in improving the status of women in India. Policymakers need to focus on gender inequality in order to combat the spread of HIV/AIDS in India. Originality/value While absolute figures indicate men are more likely to be infected with HIV/AIDS, the rate of decline is higher for men compared to women in India. We explore several plausible explanations for such observed inequality in the spread of HIV/AIDS across gender. In particular, a potentially important factor - the low status of women in society is attributable as an impediment to the spread of the disease. A case study of the relationship between gender empowerment and the spread of HIV/AIDS in the state with the highest concentration, Manipur, provides more insight to the difficulties faced by women in combating HIV/AIDS in India.