Infrastructure sustainability : differential axial shortening of concrete structures

High density development has been seen as a contribution to sustainable development. However, a number of engineering issues play a crucial role in the sustainable construction of high rise buildings. Non linear deformation of concrete has an adverse impact on high-rise buildings with complex geometries, due to differential axial shortening. These adverse effects are caused by time dependent behaviour resulting in volume change known as ‘shrinkage’, ‘creep’ and ‘elastic’ deformation. These three phenomena govern the behaviour and performance of all concrete elements, during and after construction. Reinforcement content, variable concrete modulus, volume to surface area ratio of the elements, environmental conditions, and construction quality and sequence influence on the performance of concrete elements and differential axial shortening will occur in all structural systems. Its detrimental effects escalate with increasing height and non vertical load paths resulting from geometric complexity. The magnitude of these effects has a significant impact on building envelopes, building services, secondary systems, and lifetime serviceability and performance. Analytical and test procedures available to quantify the magnitude of these effects are limited to a very few parameters and are not adequately rigorous to capture the complexity of true time dependent material response. With this in mind, a research project has been undertaken to develop an accurate numerical procedure to quantify the differential axial shortening of structural elements. The procedure has been successfully applied to quantify the differential axial shortening of a high rise building, and the important capabilities available in the procedure have been discussed. A new practical concept, based on the variation of vibration characteristic of structure during and after construction and used to quantify the axial shortening and assess the performance of structure, is presented.

A numerical method to quantify differential axial shortening in concrete buildings

Differential distortion comprising axial shortening and consequent rotation in concrete buildings is caused by the time dependent effects of “shrinkage”, “creep” and “elastic” deformation. Reinforcement content, variable concrete modulus, volume to surface area ratio of elements and environmental conditions influence these distortions and their detrimental effects escalate with increasing height and geometric complexity of structure and non vertical load paths. Differential distortion has a significant impact on building envelopes, building services, secondary systems and the life time serviceability and performance of a building. Existing methods for quantifying these effects are unable to capture the complexity of such time dependent effects. This paper develops a numerical procedure that can accurately quantify the differential axial shortening that contributes significantly to total distortion in concrete buildings by taking into consideration (i) construction sequence and (ii) time varying values of Young’s Modulus of reinforced concrete and creep and shrinkage. Finite element techniques are used with time history analysis to simulate the response to staged construction. This procedure is discussed herein and illustrated through an example.

A life jacket with holes- : a case study of 'temporary engagement' : a strategy used by Education Queensland to employ beginning secondary teachers

This research investigated the impact of Education Queensland's employment policy and practices for beginning secondary teachers appointed on temporary engagement. The context was the public secondary school sector within the state of Queensland, Australia. The study was set within a context of the changing nature of work from full-time permanent employment towards casual, fixed-term contracts, temporary and part-time employment, a trend reflected in the employment patterns for teachers within Australia. Two broad categories of literature relating to the research problem of this thesis were reviewed, namely the beginning teacher and permanency or tenure. The focus in the research literature on beginning teachers was the professional experiences of teachers within the classroom and school. There was a paucity of research that considered the working and industrial conditions of temporary employment for beginning teachers or the personal and professional implications of this form of employment. The review of the context and literature was conceptualised as a Beginning Temporary Teacher Theoretical Framework which served to inform the study. Using a qualitative case study methodology, the research techniques employed for the thesis were semi-structured interview and document analysis. A simultaneously conducted research project in which the researcher participated entitled 'Winning the Lottery? Beginning Teachers on Temporary Engagement' foregrounded this thesis in terms of refining the research question, contributing to the literature and in the selection of the participants. For this case study the perspectives of four distinct yet inter-related categories of professionals were sought. These included four beginning secondary teachers, three school administrators, a Senior Personnel Officer with Education Queensland, and a representative from the Queensland Teachers' Union. The research findings indicated that none of the beginning teachers or other professionals viewed starting a career in teaching on temporary engagement as the ideal. The negative features identified were the differential treatment received and the high level of uncertainty associated with temporary employment. Differential treatment tended to indicate 'less' entitlements, in terms of access to induction and professional development, recreational and sick leave, acceptance by and expectations of other colleagues, and avenues of redress in grievance cases. Moreover, interviews indicated a high level of uncertainty in terms of starting within the teaching profession, commencing at a new school, and a regular income. In addition, frequent changes in schools and/or cohorts of students exacerbated levels of uncertainty. The beginning teachers reported significantly decreased motivation, self-esteem and sense of belonging, and increased stress levels. There was an even more marked negative impact on those beginning teachers who had experienced a higher number of temporary engagements and schools in their first year of teaching. Conversely, strong staff support and a reasonable length of time in the one school improved the quality of the beginning teachers' experiences. The overall impact of being on temporary engagement resulted in delayed permanent position appointments, decreased commitment to particular schools and to Education Queensland as the employing authority, and for two of the beginning teachers, it produced a desire to seek alternative employment. The implementation of Education Queensland's policies relating to working conditions and entitlements for these temporary beginning teachers at the school level was revealed to be less than satisfactory. There was a tendency towards 'just-in- time' management of the beginning teacher on temporary engagement. The beginning teachers received 'less-than-messages' about access to and use of departmental documentation, support through induction and professional development, and their transition from temporary to permanent employment. To ensure a more systematic, supportive and inclusive process for managing the temporary beginning teacher, a conceptual framework entitled 'Continuums of Tension' was developed. The four continuums included permanent employment - temporary employment; system perspective - individual perspective; teaching as a profession - teaching as a job; and the permanent beginning teacher - university graduate. The general principles of the human resource policies of Education Queensland were based on a commitment to permanent employment, a system's perspective, viewing teaching as a profession and a homogeneous group of permanent beginning teachers. Contrasting with this, the beginning teacher on temporary engagement tended to operate from the position of temporary employment and a perspective that was individually based. Their priorities therefore included the 'occupational' aspects of being a temporary teacher striving to become permanent. Thus there existed a tension or contradiction between the general principles of human resource policies within Education Queensland and the employment experiences of beginning teachers on temporary engagement. The study proposed three actions for resolution to address the aforementioned tensions. The actions included: (a) the effective provision and targeted communication of information; (b) support, induction and professional development; and (c) a coordinated approach between Education Queensland, Queensland Teachers' Union, the Universities and the beginning teacher. These actions are fm1her refined to include: (a) an induction kit to suppm1 the individual through the pre-employment to permanent employee phases, (b) an extrapolation of the roles and responsibilities of Education Queensland personnel charged with supporting the beginning temporary teacher, and (c) a series of recommendations to effect a coordinated approach amongst the key stakeholders. The theoretical and conceptual frameworks have provided a means of addressing the identified needs of the beginning teacher on temporary engagement. As such, this study has contributed to the research literature on teacher employment and professionalism and aims to provide a beginning temporary teacher with managed professional and occupational support.

The differential impact of holocaust trauma across three generations

In the current thesis, the reasons for the differential impact of Holocaust trauma on Holocaust survivors, and the differential intergenerational transmission of this trauma to survivors’ children and grandchildren were explored. A model specifically related to Holocaust trauma and its transmission was developed based on trauma, family systems and attachment theories as well as theoretical and anecdotal conjecture in the Holocaust literature. The Model of the Differential Impact of Holocaust Trauma across Three Generations was tested firstly by extensive meta-analyses of the literature pertaining to the psychological health of Holocaust survivors and their descendants and secondly via analysis of empirical study data. The meta-analyses reported in this thesis represent the first conducted with research pertaining to Holocaust survivors and grandchildren of Holocaust survivors. The meta-analysis of research conducted with children of survivors is the first to include both published and unpublished research. Meta-analytic techniques such as meta-regression and sub-set meta-analyses provided new information regarding the influence of a number of unmeasured demographic variables on the psychological health of Holocaust survivors and descendants. Based on the results of the meta-analyses it was concluded that Holocaust survivors and their children and grandchildren suffer from a statistically significantly higher level or greater severity of psychological symptoms than the general population. However it was also concluded that there is statistically significant variation in psychological health within the Holocaust survivor and descendant populations. Demographic variables which may explain a substantial amount of this variation have been largely under-assessed in the literature and so an empirical study was needed to clarify the role of demographics in determining survivor and descendant mental health. A total of 124 participants took part in the empirical study conducted for this thesis with 27 Holocaust survivors, 69 children of survivors and 28 grandchildren of survivors. A worldwide recruitment process was used to obtain these participants. Among the demographic variables assessed in the empirical study, aspects of the survivors’ Holocaust trauma (namely the exact nature of their Holocaust experiences, the extent of family bereavement and their country of origin) were found to be particularly potent predictors of not only their own psychological health but continue to be strongly influential in determining the psychological health of their descendants. Further highlighting the continuing influence of the Holocaust was the finding that number of Holocaust affected ancestors was the strongest demographic predictor of grandchild of survivor psychological health. Apart from demographic variables, the current thesis considered family environment dimensions which have been hypothesised to play a role in the transmission of the traumatic impact of the Holocaust from survivors to their descendants. Within the empirical study, parent-child attachment was found to be a key determinant in the transmission of Holocaust trauma from survivors to their children and insecure parent-child attachment continues to reverberate through the generations. In addition, survivors’ communication about the Holocaust and their Holocaust experiences to their children was found to be more influential than general communication within the family. Ten case studies (derived from the empirical study data set) are also provided; five Holocaust survivors, three children of survivors and two grandchildren of survivors. These cases add further to the picture of heterogeneity of the survivor and descendant populations in both experiences and adaptations. It is concluded that the legacy of the Holocaust continues to leave its mark on both its direct survivors and their descendants. Even two generations removed, the direct and indirect effects of the Holocaust have yet to be completely nullified. Research with Holocaust survivor families serves to highlight the differential impacts of state-based trauma and the ways in which its effects continue to be felt for generations. The revised and empirically tested Model of the Differential Impact of Holocaust Trauma across Three Generations presented at the conclusion of this thesis represents a further clarification of existing trauma theories as well as the first attempt at determining the relative importance of both cognitive, interpersonal/interfamilial interaction processes and demographic variables in post-trauma psychological health and transmission of traumatic impact.

Differential roles of the pRb and Arf/p53 pathways in murine naevus and melanoma genesis

We report on a systematic analysis of genotype-specific melanocyte (MC) UVR responses in transgenic mouse melanoma models along with tumour penetrance and comparative histopathology. pRb or p53 pathway mutations cooperated with NrasQ61K to transform MCs. We previously reported that MCs migrate from the follicular outer root sheath into the epidermis after neonatal UVR. Here, we found that Arf or p53 loss markedly diminished this response. Despite this, mice carrying these mutations developed melanoma with very early age of onset after neonatal UVR. Cdk4R24C did not affect the MC migration. Instead, independent of UVR exposure, interfollicular dermal MCs were more prevalent in Cdk4R24C mice. Subsequently, in adulthood, these mutants developed dermal MC proliferations reminiscent of superficial congenital naevi. Two types of melanoma were observed in this model. The location and growth pattern of the first was consistent with derivation from the naevi, while the second appeared to be of deep dermal origin. In animals carrying the Arf or p53 defects, no naevi were detected, with all tumours ostensibly skipping the benign precursor stage in progression.

Discrimination or Differential Involvement? A Review of the Research Exploring the Impact of Indigenous Status on Sentencing

Existing court data suggest that adult Indigenous offenders are more likely than non-Indigenous defendants to be sentenced to prison but once imprisoned generally receive shorter terms. Using findings from international and Australian multivariate statistical analyses, this paper reviews the three key hypotheses advanced as plausible explanations for these differences: 1) differential involvement, 2) negative discrimination, 3) positive discrimination. Overall, prior research shows strong support for the differential involvement thesis, some support for positive discrimination and little foundation for negative discrimination in the sentencing of Indigenous defendants. Where discrimination is found, we argue that this may be explained by the lack of a more complete set of control variables in researchers’ multivariate models.

An advanced implicit meshless approach for fractional partial differential equation in computational mechanics

Recently, the numerical modelling and simulation for fractional partial differential equations (FPDE), which have been found with widely applications in modern engineering and sciences, are attracting increased attentions. The current dominant numerical method for modelling of FPDE is the explicit Finite Difference Method (FDM), which is based on a pre-defined grid leading to inherited issues or shortcomings. This paper aims to develop an implicit meshless approach based on the radial basis functions (RBF) for numerical simulation of time fractional diffusion equations. The discrete system of equations is obtained by using the RBF meshless shape functions and the strong-forms. The stability and convergence of this meshless approach are then discussed and theoretically proven. Several numerical examples with different problem domains are used to validate and investigate accuracy and efficiency of the newly developed meshless formulation. The results obtained by the meshless formations are also compared with those obtained by FDM in terms of their accuracy and efficiency. It is concluded that the present meshless formulation is very effective for the modelling and simulation for FPDE.

Exploiting system fluctuations. Differential training in physical prevention and rehabilitation programs for health and exercise

Background: Traditional causal modeling of health interventions tends to be linear in nature and lacks multidisciplinarity. Consequently, strategies for exercise prescription in health maintenance are typically group based and focused on the role of a common optimal health status template toward which all individuals should aspire. ----- ----- Materials and methods: In this paper, we discuss inherent weaknesses of traditional methods and introduce an approach exercise training based on neurobiological system variability. The significance of neurobiological system variability in differential learning and training was highlighted.----- ----- Results: Our theoretical analysis revealed differential training as a method by which neurobiological system variability could be harnessed to facilitate health benefits of exercise training. It was observed that this approach emphasizes the importance of using individualized programs in rehabilitation and exercise, rather than group-based strategies to exercise prescription.----- ----- Conclusion: Research is needed on potential benefits of differential training as an approach to physical rehabilitation and exercise prescription that could counteract psychological and physical effects of disease and illness in subelite populations. For example, enhancing the complexity and variability of movement patterns in exercise prescription programs might alleviate effects of depression in nonathletic populations and physical effects of repetitive strain injuries experienced by athletes in elite and developing sport programs.