Determination of sodium oxalate in Bayer liquor using flow-analysis incorporating an anion exchange column and tris(2,2`-bipyridyl)ruthenium(II) chemiluminescence detection

Semi-automated flow injection instrumentation, incorporating a small anion exchange column coupled with tris(2,2′-bipyridyl)ruthenium(II) (Ru(bipy)₃²⁺) chemiluminescence detection, was configured and utilised to develop rapid methodology for the determination of sodium oxalate in Bayer liquors. The elimination of both negative and positive interferences from aluminium(III) and, as yet, unknown concomitant organic species, respectively are discussed. The robustness of the methodology was considerably enhanced by using the temporally stable form of the chemiluminescence reagent, tris(2,2′-bipyridyl)ruthenium(III) perchlorate in dry acetonitrile. Real Bayer process samples were analysed and the results obtained compared well with those performed using standard methods within industrial laboratories.

Determination of sodium oxalate in Bayer process liquors using flow analysis with tris(2,2'-bipyridyl)ruthenium(II) chemiluminescence detection

The research was a detailed investigation into a challenging analytical chemistry problem for the alumina industry. The successful outcomes were derived through innovative reagent chemistry and novel instrumental development. The resultant methodology and instrumentation deployed on this most demanding sample matrix is more robust, reliable and less expensive than anything currently used in this industry worldwide.

Effect of increased temperature on erosion-corrosion under turbulent conditions in Bayer liquor

A study of the behaviour of mild steel in synthetic Bayer liquor at 25 °C and 95 °C showed that turbulent conditions had a small effect on the anodic currents at 25 °C, but caused large increases in currents at 95 °C. This may be due to the increased solubility of magnetite at the higher temperature.

Improving infant sleep and maternal mental health: a cluster randomised trial

Objectives: To determine whether a community-delivered intervention targeting infant sleep problems improves infant sleep and maternal well-being and to report the costs of this approach to the healthcare system.

Design: Cluster randomised trial.

Setting: 49 Maternal and Child Health (MCH) centres (clusters) in Melbourne, Australia.

Participants: 328 mothers reporting an infant sleep problem at 7 months recruited during October–November 2003.

Intervention: Behavioural strategies delivered over individual structured MCH consultations versus usual care.

Main outcome measures: Maternal report of infant sleep problem, depression symptoms (Edinburgh Postnatal Depression Scale (EPDS)), and SF-12 mental and physical health scores when infants were 10 and 12 months old. Costs included MCH sleep consultations, other healthcare services and intervention costs.

Results: Prevalence of infant sleep problems was lower in the intervention than control group at 10 months (56% vs 68%; adjusted OR 0.58 (95% CI: 0.36 to 0.94)) and 12 months (39% vs 55%; adjusted OR 0.50 (0.31 to 0.80)). EPDS scores indicated less depression at 10 months (adjusted mean difference –1.4 (–2.3 to –0.4) and 12 months (–1.7 (–2.6 to –0.7)). SF-12 mental health scores indicated better health at 10 months (adjusted mean difference 3.7 (1.5 to 5.8)) and 12 months (3.9 (1.8 to 6.1)). Total mean costs including intervention design, delivery and use of non-MCH nurse services were £96.93 and £116.79 per intervention and control family, respectively.

Conclusions: Implementing this sleep intervention may lead to health gains for infants and mothers and resource savings for the healthcare system.

Blood glucose meters : an independent head to head comparison

A new generation of blood glucose meters is now available for use by people with diabetes and health professionals, but little independent evaluation data is available. Previous models are prone to a variety of errors. We compared the accuracy, precision and features of the six latest meters available in Australia as of 1996. Meters studied were the Mini-Accutrend and Advantage (Boehringer Mannheim), Precision QID and Companion 2 (MediSense), Glucometer Elite (Bayer) and Lynx (National Diagnostic Products). We measured the blood glucose levels of 50 people with diabetes with these meters, and compared them to a reference method (YSI glucose analyser). Error grid analysis confirmed that accuracy of all meters was sufficient for their intended use as patient monitors. Precision was assessed using 25 samples from control solutions provided for each meter, and the coefficient of variation calculated. Improvements in strip and meter technology in some models have increased ease of use and reduced the likelihood of user error. This study, when considered with individual preferences for various features and price should assist patients in choosing a new blood glucose meter.

Semi-hyperbolic mappings in Banach spaces

The definition of semi-hyperbolic dynamical systems generated by Lipschitz continuous and not necessarily invertible mappings in Banach spaces is presented in this thesis. Like hyperbolic mappings, they involve a splitting into stable and unstable spaces, but a slight leakage from the strict invariance of the spaces is possible and the unstable subspaces are assumed to be finite dimensional. Bi-shadowing is a combination of the concepts of shadowing and inverse shadowing and is usually used to compare pseudo-trajectories calculated by a computer with the true trajectories. In this thesis, the concept of bi-shadowing in a Banach space is defined and proved for semi-hyperbolic dynamical systems generated by Lipschitz mappings. As an application to the concept of bishadowing, linear delay differential equations are shown to be bi-shadowing with respect to pseudo-trajectories generated by nonlinear small perturbations of the linear delay equation. This shows robustness of solutions of the linear delay equation with respect to small nonlinear perturbations. Complicated dynamical behaviour is often a consequence of the expansivity of a dynamical system. Semi-hyperbolic dynamical systems generated by Lipschitz mappings on a Banach space are shown to be exponentially expansive, and explicit rates of expansion are determined. The result is applied to a nonsmooth noninvertible system generated by delay differential equation. It is shown that semi-hyperbolic mappings are locally φ-contracting, where -0 is the Hausdorff measure of noncompactness, and that a linear operator is semi-hyperbolic if and only if it is φ-contracting and has no spectral values on the unit circle. The definition of φ-bi-shadowing is given and it is shown that semi-hyperbolic mappings in Banach spaces are φ-bi-shadowing with respect to locally condensing continuous comparison mappings. The result is applied to linear delay differential equations of neutral type with nonsmooth perturbations. Finally, it is shown that a small delay perturbation of an ordinary differential equation with a homoclinic trajectory is ‘chaotic’.

Evaluation of heat stress indices using physiological comparisons in an alumina refinery in a sub-tropical climate

The production of alumina involves the use of a process known as the Bayer process. This method involves the digestion of raw bauxite in sodium hydroxide at temperatures around 250°C. The resultant pregnant liquor then goes through a number of filtering and precipitation processes to obtain the aluminium oxide crystals which are then calcined to obtain the final product. The plant is situated in a sub tropical climate in Northern Australia and this combined with the hot nature of the process results in a potential for heat related illnesses to develop. When assessing a work environment for heat stress a heat stress index is often employed as a guideline and to date the Wet Bulb Globe Temperature (WBGT) has been the recommended index. There have been concerns over the past that the WBGT is not suited to the Northern Australian climate and in fact studies in other countries have suggested this is the case. This study was undertaken in the alumina plant situated in Gladstone Queensland to assess if WBGT was in fact the most suitable index for use or if another was more applicable. To this end three indices, Wet Bulb Globe Temperature (WBGT), Heat Stress Index (HSI) and Required Sweat Rate (SWreq) were compared and assessed using physiological monitoring of heart rate and surrogate core temperature. A number of different jobs and locations around the plant were investigated utilising personal and environmental monitoring equipment. These results were then collated and analysed using a computer program written as part of the study for the manipulation of the environmental data . Physiological assessment was carried out using methods approved by international bodies such as National Institute for Occupational Safety & Health (NIOSH) and International Standards Organisation (ISO) and incorporated the use of a ‘Physiological Factor’ developed to enable the comparison of predicted allowable exposure times and strain on the individual. Results indicated that of the three indices tested, Required Sweat Rate was found to be the most suitable for the climate and in the environment of interest. The WBGT system was suitable in areas in the moderate temperature range (ie 28 to 32°C) but had some deficiencies above this temperature or where the relative humidity exceeded approximately 80%. It was however suitable as a first estimate or first line indicator. HSI over-estimated the physiological strain in situations of high temperatures, low air flows and exaggerated the benefit of artificial air flows on the worker in certain environments ie. fans.

Stability of oxide films formed on mild steel in turbulent flow conditions of alkaline solutions at elevated temperatures

In the industries involving alkaline solutions in different process streams, the nature and stability of oxide films formed on the metallic surfaces determine the rates of erosion–corrosion of the equipment. In the present study the characteristics of the oxide films formed on AISI 1020 steel in a 2.75 M sodium hydroxide solution at temperatures up to 175°C, have been investigated by employing electrochemical techniques of cyclic voltammetry and chronoamperometry. The experiments were carried out in an autoclave system based upon a ‘rotating cylinder electrode’ geometry to determine the effects of turbulence on the stability of the films. The results suggest that little protection is afforded in the active region (at about −0.8 V_SHE). In the passive region at low potentials (−0.6 V to −0.4 V_SHE), it appears the films are compact and more stable, and therefore provide good protection. At higher potentials (>−0.4 V_SHE) in the passive region, the results suggest that film formation and dissolution occur simultaneously and the increase in temperature and turbulence causes a breakdown of the passive film resulting in a situation similar to nonprotective magnetite growth.

The Cool Little Kids randomised controlled trial population-level early prevention for anxiety disorders

Background: The World Health Organization predicts that by 2030 internalising problems (e.g. depression and anxiety) will be second only to HIV/AIDS in international burden of disease. Internalising problems affect 1 in 7 school aged children, impacting on peer relations, school engagement, and later mental health, relationships and employment. The development of early childhood prevention for internalising problems is in its infancy. The current study follows two successful ‘efficacy’ trials of a parenting group intervention to reduce internalising disorders in temperamentally inhibited preschool children. Cool Little Kids is a population-level randomised trial to determine the impacts of systematically screening preschoolers for inhibition then offering a parenting group intervention, on child internalising problems and economic costs at school entry.
Methods/Design: This randomised trial will be conducted within the preschool service system, attended by more than 95% of Australian children in the year before starting school. In early 2011, preschool services in four local government areas in Melbourne, Australia, will distribute the screening tool. The ≈16% (n≈500) with temperamental inhibition will enter the trial. Intervention parents will be offered Cool Little Kids, a 6-session group program in the local community, focusing on ways to develop their child’s bravery skills by reducing overprotective parenting interactions. Outcomes one and two years post-baseline will comprise child internalising diagnoses and symptoms, parenting interactions, and parent wellbeing. An economic evaluation (costconsequences framework) will compare incremental differences in costs of the intervention versus control children to incremental differences in outcomes, from a societal perspective. Analyses will use the intention-to-treat principle, using logistic and linear regression models (binary and continuous outcomes respectively) to compare outcomes between the trial arms.
Discussion: This trial addresses gaps for internalising problems identified in the 2004 World Health Organization Prevention of Mental Disorders report. If effective and cost-effective, the intervention could readily be applied at a population level. Governments consider mental health to be a priority, enhancing the likelihood that an effective early prevention program would be adopted in Australia and internationally.

Preventing mental health problems in children : the families in mind population-based cluster randomised controlled trial.

Background

Externalising and internalising problems affect one in seven school-aged children and are the single strongest predictor of mental health problems into early adolescence. As the burden of mental health problems persists globally, childhood prevention of mental health problems is paramount. Prevention can be offered to all children (universal) or to children at risk of developing mental health problems (targeted). The relative effectiveness and costs of a targeted only versus combined universal and targeted approach are unknown. This study aims to the effectiveness, costs and uptake of two approaches to early childhood prevention of mental health problems ie: a Combined universal-targeted approach, versus a Targeted only approach, in comparison to current primary care services (Usual care).
Design

Three armed, population-level cluster randomised trial (2010-2014) within the universal, well child Maternal Child Health system, attended by more than 80% of families in Victoria, Australia at infant age eight months. Participants: Families of eight month old children from nine participating local government areas. Randomised to one of three groups: Combined, Targeted or Usual care. Intervention: (a) the Combined universal and targeted program where all families are offered the universal Toddlers Without Tears group parenting program followed by the targeted Family Check-Up one-on-one program or (b) the Targeted Family Check-Up program. The Family Check-Up program is only offered to children at risk of behavioural problems. Analysis: Participants will be analysed according to the trial arm to which they were randomised, using logistic and linear regression models to compare primary and secondary outcomes. An economic evaluation (cost consequences analysis) will compare incremental costs to all incremental outcomes from a societal perspective.
Discussion

This trial will inform public health policy by making recommendations about the effectiveness and cost-effectiveness of these early prevention programs. If effective prevention programs can be implemented at the population level, the growing burden of mental health problems could be curbed.

Big pharma in legal battles for monopoly prices in India

Two large multinational pharmaceutical companies are fighting for patents and monopoly pricing in Indian courts. The outcomes of the cases – involving Novartis and Bayer – are likely to determine the country’s future as a major global supplier of low-cost essential medicines.