Development of realistic design fire time-temperature curves for the testing of cold-formed steel wall system

Fire resistance rating of light gauge steel frame (LSF) wall systems is obtained from fire tests based on the standard fire time-temperature curve. However, fire severity has increased in modern buildings due to higher fuel loads as a result of modern furniture and light weight constructions that make use of thermoplastics materials, synthetic foams and fabrics. Some of these materials are high in calorific values and increase both the spread of fire growth and heat release rate, thus increasing the fire severity beyond that of the standard fire curve. Further, the standard fire curve does not include a decay phase that is present in natural fires. Despite the increasing usage of LSF walls, their behaviour in real building fires is not fully understood. This paper presents the details of a research study aimed at developing realistic design fire curves for use in the fire tests of LSF walls. It includes a review of the characteristics of building fires, previously developed fire time-temperature curves, computer models and available parametric equations. The paper highlights that real building fire time-temperature curves depend on the fuel load representing the combustible building contents, ventilation openings and thermal properties of wall lining materials, and provides suitable values of many required parameters including fuel loads in residential buildings. Finally, realistic design fire time-temperature curves simulating the fire conditions in modern residential buildings are proposed for the testing of LSF walls.

Demographics and survivial of a cohort of blood and breast cancer patients who developed heart failure following cancer treatment

Background/Aim: Cardiotoxicity resulting in heart failure is a devastating complication of cancer therapy. It is possible that a patient may survive cancer only to develop heart failure (HF), which is more deadly than cancer. The aim of this project was to profile the characteristics of patients at risk of cancer treatment induced heart failure. Methods: Linked Health Data Analysis of Queensland Cancer Registry (QCR) from 1996-2009, Death Registry and Hospital Administration records for HF and chemotherapy admissions were reviewed. Index heart failure admission must have occurred after the date of cancer registry entry. Results: A total of 15,987 patients were included in this analysis; 1,062 (6.6%) had chemotherapy+HF admission (51.4% Female) and 14,925 (93.4%) chemotherapy_no HF admission. Median age of chemotherapy+HF patients was 67 years (IQR 58 to 75) vs. 54 years (IQR 44 to 64) for chemotherapy_no HF admission. Chemotherapy+HF patients had increased risk of all cause mortality (HR 2.79 [95% CI 2.58-3.02] and 1.67 [95% CI, 1.54 to 1.81] after adjusting for age, sex, marital status, country of birth, cancer site and chemotherapy dose). Index HF admission occurred within one year of cancer diagnosis in 47% of HF patients with 80% of patinets having there index admission with 3 years. The number of chemotherapy cycles was not associated with significant reduction in survival time in chemotherapy+HF patients. Mean survival for heart failure patients was 5.3 years (95% CI, 4.99 - 5.62) vs.9.57 years (95% CI, 9.47-9.68) for chemotherapy_no HF admission patients. Conclusion: All-cause mortality was 67% higher in patients diagnosed with HF following chemotherapy in adjusted analysis for covariates. Methods to improve and better coordinate of the interdisciplinary care for cancer patients with HF involving cardiologists and oncologists are required, including evidence-based guidelines for the comprehensive assessment, monitoring and management of this cohort.

A new ambiguity acceptance test threshold determination method with controllable failure rate

The ambiguity acceptance test is an important quality control procedure in high precision GNSS data processing. Although the ambiguity acceptance test methods have been extensively investigated, its threshold determine method is still not well understood. Currently, the threshold is determined with the empirical approach or the fixed failure rate (FF-) approach. The empirical approach is simple but lacking in theoretical basis, while the FF-approach is theoretical rigorous but computationally demanding. Hence, the key of the threshold determination problem is how to efficiently determine the threshold in a reasonable way. In this study, a new threshold determination method named threshold function method is proposed to reduce the complexity of the FF-approach. The threshold function method simplifies the FF-approach by a modeling procedure and an approximation procedure. The modeling procedure uses a rational function model to describe the relationship between the FF-difference test threshold and the integer least-squares (ILS) success rate. The approximation procedure replaces the ILS success rate with the easy-to-calculate integer bootstrapping (IB) success rate. Corresponding modeling error and approximation error are analysed with simulation data to avoid nuisance biases and unrealistic stochastic model impact. The results indicate the proposed method can greatly simplify the FF-approach without introducing significant modeling error. The threshold function method makes the fixed failure rate threshold determination method feasible for real-time applications.

Numerical investigation of deformation and failure mechanisms of osteopontin-hydroxyapatite interfaces and mineralized collagen fibril arrays

This thesis is a comprehensive study of deformation and failure mechanisms in bone at nano- and micro-scale levels. It explores the mechanical behaviour of osteopontin-hydroxyapatite interfaces and mineralized collagen fibril arrays, through atomistic molecular dynamics and finite element simulations. This thesis shows some main factors contributing to the excellent material properties of bone and provides some guidelines for development of new artificial biological materials and medical implants.

Meeting the nutrition challenge of stage 3 renal failure : considerations for nursing practice

Self-care management is needed for effective management of chronic kidney disease. The main aim for treatment or management of chronic kidney disease is to delay the worsening of kidney function, and to prevent or to manage the co-morbidities. Selfcare management is not easy, and patients will face many challenges, especially when they cannot get use to the new treatment plan. One of the challenges they face is dietary restriction, which is a very important aspect in any self-care management programme. Chronic kidney disease patients require a low-protein, low-sodium, low-potassium, and low-phosphorus diet. There are several strategies patients can undertake to ensure adherence, such as self-monitoring their dietary habits and type of food consumed using a food diary; involving social support, such as family members and spouse to help them to adhere to their diet restrictions; setting goals and providing positive reinforcement when they achieved the targeted goals; joining self-management programmes to equip themselves with the necessary skills so that they can better adhere to the treatment regimes, including diet restriction; and lastly, having the knowledge about their regime, and using this knowledge to help them understand and improve their adherence.

A multiple case study of NAPLAN numeracy testing of Year 9 students in three Queensland secondary schools

This thesis reports on a multiple case study of the actions of three Queensland secondary schools in the context of Year 9 NAPLAN numeracy testing, focusing on their administrative practices, curriculum, pedagogy and assessment. It was established that schools have found it both challenging and costly to operate in an environment of educational reform generally, and NAPLAN testing in particular. The lack of a common understanding of numeracy and the substantial demands of implementing the Australian Curriculum have impacted on schools' ability to prepare students appropriately for NAPLAN numeracy tests. It was concluded that there is scope for schools to improve their approaches to NAPLAN numeracy testing in a way that maximises learning as well as test outcomes.

A novel ambiguity acceptance test threshold determination method with controllable failure rate

Ambiguity validation as an important procedure of integer ambiguity resolution is to test the correctness of the fixed integer ambiguity of phase measurements before being used for positioning computation. Most existing investigations on ambiguity validation focus on test statistic. How to determine the threshold more reasonably is less understood, although it is one of the most important topics in ambiguity validation. Currently, there are two threshold determination methods in the ambiguity validation procedure: the empirical approach and the fixed failure rate (FF-) approach. The empirical approach is simple but lacks of theoretical basis. The fixed failure rate approach has a rigorous probability theory basis, but it employs a more complicated procedure. This paper focuses on how to determine the threshold easily and reasonably. Both FF-ratio test and FF-difference test are investigated in this research and the extensive simulation results show that the FF-difference test can achieve comparable or even better performance than the well-known FF-ratio test. Another benefit of adopting the FF-difference test is that its threshold can be expressed as a function of integer least-squares (ILS) success rate with specified failure rate tolerance. Thus, a new threshold determination method named threshold function for the FF-difference test is proposed. The threshold function method preserves the fixed failure rate characteristic and is also easy-to-apply. The performance of the threshold function is validated with simulated data. The validation results show that with the threshold function method, the impact of the modelling error on the failure rate is less than 0.08%. Overall, the threshold function for the FF-difference test is a very promising threshold validation method and it makes the FF-approach applicable for the real-time GNSS positioning applications.

Confirmatory factor analysis and invariance testing of the Young Carer of Parents Inventory (YCOPI)

Objective Research into youth caregiving in families where a parent experiences a significant medical condition has been hampered by a lack of contextually sensitive measures of the nature and breadth of young caregiving experiences. This study examined the factor structure and measurement invariance of such a measure called the Young Carer of Parents Inventory (YCOPI; Pakenham et al., 2006) using confirmatory factor analysis across 3 groups of youth. The YCOPI has 2 parts: YCOPI-A with 5 factors assessing caregiving experiences that are applicable to all caregiving contexts; YCOPI-B with 4 factors that tap dimensions related to youth caregiving in the context of parent illness. Design Two samples (ages 9–20 years) were recruited: a community sample of 2,429 youth from which 2 groups were derived (“healthy” family [HF], n = 1760; parental illness [PI], n = 446), and a sample of 130 youth of a parent with multiple sclerosis). Results With some modification, the YCOPI-A demonstrated a replicable factor structure across 3 groups, and exhibited only partial measurement invariance across the HF and PI groups. The impact of assuming full measurement invariance on latent mean differences appeared small, supporting use of the measure in research and applied settings when estimated using latent factors and controlling for measurement invariance. PI youth reported significantly higher scores than did HF youth on all YCOPI-A subscales. The YCOPI-B requires some modifications, and further development work is recommended. Conclusion The factor structure that emerged and the addition of new items constitutes the YCOPI-Revised. Findings support the use of the YCOPI-Revised in research and applied settings.

A strain-based failure criterion for pillar stability analysis

Strain-based failure criteria have several advantages over stress-based failure criteria: they can account for elastic and inelastic strains, they utilise direct, observables effects instead of inferred effects (strain gauges vs. stress estimates), and model complete stress-strain curves including pre-peak, non-linear elasticity and post-peak strain weakening. In this study, a strain-based failure criterion derived from thermodynamic first principles utilising the concepts of continuum damage mechanics is presented. Furthermore, implementation of this failure criterion into a finite-element simulation is demonstrated and applied to the stability of underground mining coal pillars. In numerical studies, pillar strength is usually expressed in terms of critical stresses or stress-based failure criteria where scaling with pillar width and height is common. Previous publications have employed the finite-element method for pillar stability analysis using stress-based failure criterion such as Mohr-Coulomb and Hoek-Brown or stress-based scalar damage models. A novel constitutive material model, which takes into consideration anisotropy as well as elastic strain and damage as state variables has been developed and is presented in this paper. The damage threshold and its evolution are strain-controlled, and coupling of the state variables is achieved through the damage-induced degradation of the elasticity tensor. This material model is implemented into the finite-element software ABAQUS and can be applied to 3D problems. Initial results show that this new material model is capable of describing the non-linear behaviour of geomaterials commonly observed before peak strength is reached as well as post-peak strain softening. Furthermore, it is demonstrated that the model can account for directional dependency of failure behaviour (i.e. anisotropy) and has the potential to be expanded to environmental controls like temperature or moisture.

Predictors of recent HIV testing among male street laborers in urban Vietnam

This study assessed the prevalence of and factors associated with HIV testing among male street laborers. In a cross-sectional survey, social mapping was done to recruit and interview 450 men aged 18–59 years in Hanoi. Although many of these men engaged in multiple risk behaviors for HIV, only 19.8 percent had been tested for HIV. A modified theoretical model provided better fit than the conventional Information–Motivation–Behavioral Skills model, as it explained much more variance in HIV testing. This model included three Information–Motivation–Behavioral components and four additional factors, namely, the origin of residence, sexual orientation, the number of sexual partners, and the status of condom use.