Adiabatic compression testing - part II : background and approach to estimating severity of test methodology

Adiabatic compression testing of components in gaseous oxygen is a test method that is utilized worldwide and is commonly required to qualify a component for ignition tolerance under its intended service. This testing is required by many industry standards organizations and government agencies; however, a thorough evaluation of the test parameters and test system influences on the thermal energy produced during the test has not yet been performed. This paper presents a background for adiabatic compression testing and discusses an approach to estimating potential differences in the thermal profiles produced by different test laboratories. A “Thermal Profile Test Fixture” (TPTF) is described that is capable of measuring and characterizing the thermal energy for a typical pressure shock by any test system. The test systems at Wendell Hull & Associates, Inc. (WHA) in the USA and at the BAM Federal Institute for Materials Research and Testing in Germany are compared in this manner and some of the data obtained is presented. The paper also introduces a new way of comparing the test method to idealized processes to perform system-by-system comparisons. Thus, the paper introduces an “Idealized Severity Index” (ISI) of the thermal energy to characterize a rapid pressure surge. From the TPTF data a “Test Severity Index” (TSI) can also be calculated so that the thermal energies developed by different test systems can be compared to each other and to the ISI for the equivalent isentropic process. Finally, a “Service Severity Index” (SSI) is introduced to characterizing the thermal energy of actual service conditions. This paper is the second in a series of publications planned on the subject of adiabatic compression testing.

Determination of burn criterion for promoted combustion testing

Promoted ignition testing [1–3] is used to determine the relative flammability of metal rods in oxygen-enriched atmospheres. In these tests, a promoter is used to ignite each metal rod to start the sample burning. Experiments were performed to better understand the promoted ignition test by obtaining insight into the effect a burning promoter has on the preheating of a test sample. Test samples of several metallic materials were prepared and coupled to fast-responding thermocouples along their length. Various ignition promoters were used to ignite the test samples. The thermocouple measurements and test video were synchronized to determine temperature increase with respect to time and length along each test sample. A recommended length of test sample that must be consumed to be considered a flammable material was determined based on the preheated zone measured from these tests. This length was determined to be 30 mm (1.18 in.). Validation of this length and its rationale are presented.

Regulatory approaches to genetic testing in insurance

Rapid advancements in the field of genetic science have engendered considerable debate, speculation, misinformation and legislative action worldwide. While programs such as the Human Genome Project bring the prospect of seemingly miraculous medical advancements within imminent reach, they also create the potential for significant invasions of traditional areas of privacy and human dignity through laying the potential foundation for new forms of discrimination in insurance, employment and immigration regulation. The insurance industry, which has of course, traditionally been premised on discrimination as part of its underwriting process, is proving to be the frontline of this regulatory battle with extensive legislation, guidelines and debate marking its progress.

Parental physical activity : exploring the role of social support

Objectives: To explore the influence of social support on parental physical activity (PA). Methods: Forty parents (21 mothers, 19 fathers) participated in semistructured individual or group interviews. Data were analyzed using thematic content analysis.---------- Results: Instrumental (eg, providing child care, taking over chores), emotional (eg, encouragement, companionship), and informational support (eg, ideas and advice) as well as reciprocal support (eg, giving as well as receiving support) and autonomy support (eg, respecting one’s choices) are important for parents’ PA behavior. However, having support for being active is not straightforward in that many parents discussed issues that inhibited the facilitative nature of social support for PA performance (eg, guilt in getting help). Conclusions: Results highlight the complex nature of social support in facilitating parental PA.

Website physical activity interventions : preferences of potential users

Information and communication technologies (particularly websites and e-mail) have the potential to deliver health behavior change programs to large numbers of adults at low cost. Controlled trials using these new media to promote physical activity have produced mixed results. User-centered development methods can assist in understanding the preferences of potential participants for website functions and content, and may lead to more effective programs. Eight focus group discussions were conducted with 40 adults after they had accessed a previously trialed physical activity website. The discussions were audio taped, transcribed and interpreted using a themed analysis method. Four key themes emerged: structure, interactivity, environmental context and content. Preferences were expressed for websites that include simple interactive features, together with information on local community activity opportunities. Particular suggestions included online community notice boards, personalized progress charts, e-mail access to expert advice and access to information on specific local physical activity facilities and services. Website physical activity interventions could usefully include personally relevant interactive and environmentally focused features and services identified through a user-centered development process.

Discount rates in disarray : evidence on flawed goodwill impairment testing

Carlin and Finch, this issue, compare goodwill impairment discount rates used by a sample of large Australian firms with ‘independently’ generated discount rates. Their objective is to empirically determine whether managers opportunistically select goodwill discount rates subsequent to the 2005 introduction of International Financial Reporting Standards (IFRS) in Australia. This is a worthwhile objective given that IFRS introduced an impairment regime, and within this regime, discount rate selection plays a key role in goodwill valuation decisions. It is also timely to consider the goodwill valuation issue. Following the recent downturn in the economy, there is a high probability that many firms will be forced to write down impaired goodwill arising from boom period acquisitions. Hence, evidence of bias in rate selection is likely to be of major concern to investors, policymakers and corporate regulators. Carlin and Finch claim their findings provide evidence of such bias. In this commentary I review the validity of their claims.

Neighborhood disadvantage and physical activity : baseline results from the HABITAT multilevel longitudinal study

PURPOSE: To examine the association between neighborhood disadvantage and physical activity (PA). ---------- METHODS: We use data from the HABITAT multilevel longitudinal study of PA among mid-aged (40-65 years) men and women (n=11, 037, 68.5% response rate) living in 200 neighborhoods in Brisbane, Australia. PA was measured using three questions from the Active Australia Survey (general walking, moderate, and vigorous activity), one indicator of total activity, and two questions about walking and cycling for transport. The PA measures were operationalized using multiple categories based on time and estimated energy expenditure that were interpretable with reference to the latest PA recommendations. The association between neighborhood disadvantage and PA was examined using multilevel multinomial logistic regression and Markov Chain Monte Carlo simulation. The contribution of neighborhood disadvantage to between-neighborhood variation in PA was assessed using the 80% interval odds ratio. ---------- RESULTS: After adjustment for sex, age, living arrangement, education, occupation, and household income, reported participation in all measures and levels of PA varied significantly across Brisbane’s neighborhoods, and neighborhood disadvantage accounted for some of this variation. Residents of advantaged neighborhoods reported significantly higher levels of total activity, general walking, moderate, and vigorous activity; however, they were less likely to walk for transport. There was no statistically significant association between neighborhood disadvantage and cycling for transport. In terms of total PA, residents of advantaged neighborhoods were more likely to exceed PA recommendations. ---------- CONCLUSIONS: Neighborhoods may exert a contextual effect on residents’ likelihood of participating in PA. The greater propensity of residents in advantaged neighborhoods to do high levels of total PA may contribute to lower rates of cardiovascular disease and obesity in these areas

Paediatric obesity, physical activity and the musculoskeletal system

The current epidemic of paediatric obesity is consistent with a myriad of health-related comorbid conditions. Despite the higher prevalence of orthopaedic conditions in overweight children, a paucity of published research has considered the influence of these conditions on the ability to undertake physical activity. As physical activity participation is directly related to improvements in physical fitness, skeletal health and metabolic conditions, higher levels of physical activity are encouraged, and exercise is commonly prescribed in the treatment and management of childhood obesity. However, research has not correlated orthopaedic conditions, including the increased joint pain and discomfort that is commonly reported by overweight children, with decreases in physical activity. Research has confirmed that overweight children typically display a slower, more tentative walking pattern with increased forces to the hip, knee and ankle during 'normal' gait. This research, combined with anthropometric data indicating a higher prevalence of musculoskeletal malalignment in overweight children, suggests that such individuals are poorly equipped to undertake certain forms of physical activity. Concomitant increases in obesity and decreases in physical activity level strongly support the need to better understand the musculoskeletal factors associated with the performance of motor tasks by overweight and obese children.

Understanding parental physical activity : meanings, habits, and social role influence

Objectives: The research aimed to explore parents’ understandings of physical activity (PA), patterns of PA-related behaviour, and how constructions of social role expectations might influence their PA behaviour. Design and Method: Using a qualitative descriptive design and adopting a social constructionism approach to broaden interpretations of parents’ understandings, 40 adults (21 mothers, 19 fathers; aged 23 to 49 years) living in South East Queensland, Australia participated in semi-structured individual and group interviews. The interviews were analysed using thematic analysis. Results: Parents had clear understandings of what constitutes PA and engaged in various activities which were integrated with or independent of the children. Being active with children, however, was not always constructed favourably in which many parents described the difficulties of being active with their children. All individuals experienced changes in their PA behaviours after having children. For most, a decline in PA level, intensity, and structure was experienced; however, some did experience parenthood as a time to be active. A level of acceptance for the lack of activity performed was also expressed as were feelings of resentment and envy for those who maintained previous activity habits. Parenting and partner roles were considered most influential on PA-related behaviour and were constructed in ways that had both positive and negative influences on activity performance. Parents, however, were empowered to construct strategies to resolve conflicts between social role performance and being active. Conclusion: Results show that parents experience unique difficulties that intervention work should consider when designing programs aimed at increasing parental PA.

Physical and environmental determinants

This chapter describes physical and environmental determinants of the health of Australians, providing a background to the development of successful public health activity. Health determinants are the biomedical, genetic, behavioural, socio-economic and environmental factors that impact on health and wellbeing. These determinants can be influenced by interventions and by resources and systems (AIHW 2006). Many factors combine to affect the health of individuals and communities. People’s circumstances and the environment determine whether the population is healthy or not. Factors such as where people live, the state of their environment, genetics, their education level and income, and their relationships with friends and family, all are likely to impact on their health. The determinants of population health reflect the context of people’s lives; however, people are very unlikely to be able to control many of these determinants (WHO 2007). This chapter and Chapter 6 illustrate how various determinants can relate to, and influence other determinants, as well as health and wellbeing. We believe it is particularly important to provide an understanding of determinants and their relationship to health and illness in order to provide a structure in which a broader conceptualisation of health can be placed. Determinants of health do not exist in isolation from one another. More frequently they work together in a complex system. What is clear to anyone who works in public health is that many factors impact on the health and wellbeing of people. For example, in the next chapter we discuss factors such as living and working conditions, social support, ethnicity and class, income, housing, work stress and the impact of education on the length and quality of people’s lives. In 1974, the influential ‘Lalonde Report’ (Lalonde 1974) described key factors that impact on health status. These factors included lifestyle, environment, human biology and health services. Taking a population health approach builds on the Lalonde Report, and recognises that a range of factors, such as living and working conditions and the distribution of wealth in society, interact to determine the health status of a population. Tackling health determinants has great potential to reduce the burden of disease and promote the health of the general population. In summary, we understand very clearly now that health is determined by the complex interactions between individual characteristics, social and economic factors and physical environments; the entire range of factors that impact on health must be addressed if we are to make significant gains in population health, and focussing interventions on the health of the population or significant sub-populations can achieve important health gains. In 2007, the Australian Government included in the list of National Health Priority Areas the following health issues: cancer control, injury prevention and control, cardiovascular health, diabetes mellitus, mental health, asthma, and arthritis and musculoskeletal conditions. The National Health Priority Areas set the agenda for the Commonwealth, States and Territories, Local Governments and not-for-profit organisations to place attention on those areas considered to be the major foci for action. Many of these health issues are discussed in this chapter and the following chapter.

Degradation of piezoelectric fluropolymers in space environments

The performance criteria of piezoelectric polymers based on polyvinylidene flouride (PVDF) in complex space environments have been evaluated. Thin films of these materials are being explored as in-situ responsive materials for large aperture space-based telescopes with the shape deformation and optical features dependent on long-term deformation and optical features dependent on long-term degradation effects, mainly due to thermal cycling, vacuum UV exposure and atomic oxygen. A summary of previous studies related to materials testing and performance prediction based on a laboratory environment is presented. The degradation pathways are a combination of molecular chemical changes primarily induced via radiative damage and physical degradation processes due to temperature and atomic oxygen exposure resulting in depoling, loss of orientation and surface erosing. Experimental validation for these materials to be used in space is being conducted as part of MISSE-6 (Materials International Space Station Experiment) with an overview of the experimental strategies discussed here.

Testing a tri-partite contingent model of engineering cultures : a pilot study

For some time there has been a growing awareness of organizational culture and its impact on the functioning of engineering and maintenance departments. Those wishing to implement contemporary maintenance regimes (e.g. condition based maintenance) are often encouraged to develop “appropriate cultures” to support a new method’s introduction. Unfortunately these same publications often fail to specifically articulate the cultural values required to support those efforts. In the broader literature, only a limited number of case examples document the cultural values held by engineering asset intensive firms and how they contribute to their success (or failure). Consequently a gap exists in our knowledge of what engineering cultures currently might look like, or what might constitute a best practice engineering asset culture. The findings of a pilot study investigating the perceived ideal characteristics of engineering asset cultures are reported. Engineering managers, consultants and academics (n=47), were surveyed as to what they saw were essential attributes of both engineering cultures and engineering asset personnel. Valued cultural elements included those orientated around continuous improvement, safety and quality. Valued individual attributes included openness to change, interpersonal skills and conscientiousness. The paper concludes with a discussion regarding the development of a best practice cultural framework for practitioners and engineering managers.

Part 1. Chemical and Physical Restraints in the Management of Mechanically Ventilated Patients in the ICU: Contributing Factors

Chemical and physical restraints are frequently used in the intensive care unit (ICU) to control agitated patients and to prevent self-harm and unplanned extubations. Published work relating to the numerous issues of the care and treatment strategies for these patients remains conflicting and unclear. Literature regarding sedation and chemical restraint reveals a trend towards management with lighter sedation, use of sedation assessment tools and sedation protocols. It remains unclear which treatment is best for agitated and delirious patients, and the evidence on the effect of sedation is conflicting. A large portion of the literature on the use of physical restraint is from general hospital wards and residential homes, and not from the ICU environment. The purpose of this paper is to provide a summary of the existing literature on the use of physical and chemical restraints in the ICU setting. In Part 1 of this two-part paper, the evidence on chemical and physical restraints is explored with specific focus on definition of terms, unplanned

Part 2. Chemical and physical restraints in the management of mechanically ventilated patients in the ICU: A patient perspective

An important goal of the care for the mechanically ventilated patient is to minimize patient discomfort and anxiety. This is partly achieved by frequent use of chemical and physical restraints. The majority of patients in intensive care will receive some form of sedation. The goal and use of sedation has changed considerably over the past few decades with literature evidencing trends toward overall lighter sedation levels and daily interruption of sedation. Conversely, the use of physical restraint for the ventilated patient in ICU differs considerably between nations and continents. A large portion of the literature on the use of physical restraint is from general hospital wards and residential homes, and not from the ICU environment. Recent literature suggests minimal use of physical restraint in the ICU, and that reduction programmes have been initiated. However, very few papers illuminate the patient's experience of physical and chemical restraints as a treatment strategy. In Part 1 of this two-part review, the evidence on chemical and physical restraints was explored with specific focus on definitions of terms, unplanned extubation, agitation, delirium as well as the impact of nurse–patient ratios in the ICU on these issues. This paper, Part 2, examines the evidence related to chemical and physical restraints from the mechanically ventilated patient's perspective.

The contribution of physical activity and sedentary behaviours to the growth and development of children and adolescents : implications for overweight and obesity

The obesity epidemic is a global trend and is of particular concern in children. Recent reports have highlighted the severity of obesity in children by suggesting: “today's generation of children will be the first for over a century for whom life expectancy falls.” This review assesses the evidence that identifies the important role of physical activity in the growth, development and physical health of young people, owing to its numerous physical and psychological health benefits. Key issues, such as “does a sedentary lifestyle automatically lead to obesity” and “are levels of physical activity in today's children less than physical activity levels in children from previous generations?”, are also discussed. Today's environment enforces an inactive lifestyle that is likely to contribute to a positive energy balance and childhood obesity. Whether a child or adolescent, the evidence is conclusive that physical activity is conducive to a healthy lifestyle and prevention of disease. Habitual physical activity established during the early years may provide the greatest likelihood of impact on mortality and longevity. It is evident that environmental factors need to change if physical activity strategies are to have a significant impact on increasing habitual physical activity levels in children and adolescents. There is also a need for more evidence-based physical activity guidelines for children of all ages. Efforts should be concentrated on facilitating an active lifestyle for children in an attempt to put a stop to the increasing prevalence of obese children