644 research outputs found

    Smouldering Remediation: Transient Effects of Front Propagation

    Get PDF
    Remediation of sites contaminated with non-aqueous phase liquids (NAPLs) presents a significant challenge, particularly for complex and high molecular weight compounds such as coal tar and creosote. Self-sustaining Treatment for Active Remediation (STAR) is an innovative remediation technology based on the principles of smouldering combustion, which has shown potential for rapid destruction of source zone contaminants. The success of smouldering remediation has been previously demonstrated both at the laboratory and field scale, however, these studies have focused primarily on the overall degree of remediation. Laboratory column experiments were employed to identify key transient processes that have the potential to influence smouldering metrics. It was found that downward liquid fuel mobilization can occur in taller systems operated at low air flow rates, and may result in elevated peak temperatures and a slowing of the propagation velocity of the trailing edge of the smouldering front. Numerical simulations and an analytical model were used to further understand experimental observations and can be used as a simple tool to predict the potential for liquid fuel mobility under different experimental conditions. It was also found that the distribution of heat within a smouldering system influences the transport of condensable products. The processes of fuel volatilization, aerosolization, condensation and deposition are important for gaseous mass transport and impact the rate of mass loss over time. The relative proportion of fuel combustion to gaseous mass transport is expected to be a function of fuel type, and may also be manipulated via operational parameters such as injection air flux

    ERTS-1 imagery use in reconnaissance prospecting: Evaluation of commercial utility of ERTS-1 imagery in structural reconnaissance for minerals and petroleum

    Get PDF
    The author has identified the following significant results. Five areas in North America (North Slope-Alaska, Superior Province-Canada, Williston Basin-Montana, Colorado, and New Mexico-West Texas) are being studied for discernibility of geological evidence on ERTS-1 imagery. Evidence mapped is compared with known mineral/hydrocarbon accumulations to determine the value of the imagery in commercial exploration programs. Evaluation has proceeded in the New Mexico-Texas area, and to date, results have been better than expected. Clearly discernible structural lineaments in this area are evident on the photographs. Comparison of this evidence with known major mining localities in New Mexico indicates a clear pattern of coincidence between the lineaments and mining localities. In West Texas, lineament and geomorphological evidence obtainable from the photographs define the petroleum-productive Central Basin Platform. Based on evaluation of results in the New Mexico-West Texas area and on cursory results in the other four areas of North America, it is concluded that ERTS-1 imagery will be extremely valuable in defining the regional and local structure in any commercial exploration program

    Validity of a pictorial perceived exertion scale for effort estimation and effort production during stepping exercise in adolescent children

    Get PDF
    This is the author's PDF version of an article published in European Physical Education Review ©2002. The definitive version is available at http://epe.sagepub.com.Recent developments in the study of paediatric effort perception have continued to emphasise the importance of child-specific rating scales. The purpose of this study was to examine the validity of an illustrated 1 – 10 perceived exertion scale; the Pictorial Children’s Effort Rating Table (PCERT). 4 class groups comprising 104 children; 27 boys and 29 girls, aged 12.1±0.3 years and 26 boys, 22 girls, aged 15.3±0.2 years were selected from two schools and participated in the initial development of the PCERT. Subsequently, 48 of these children, 12 boys and 12 girls from each age group were randomly selected to participate in the PCERT validation study. Exercise trials were divided into 2 phases and took place 7 to 10 days apart. During phase 1, children completed 5 x 3-minute incremental stepping exercise bouts interspersed with 2-minute recovery periods. Heart rate (HR) and ratings of exertion were recorded during the final 15 s of each exercise bout. In phase 2 the children were asked to regulate their exercising effort during 4 x 4-minute bouts of stepping so that it matched randomly prescribed PCERT levels (3, 5, 7 and 9). Analysis of data from Phase 1 yielded significant (P<0.01) relationships between perceived and objective (HR) effort measures for girls. In addition, the main effects of exercise intensity on perceived exertion and HR were significant (P<0.01); perceived exertion increased as exercise intensity increased and this was reflected in simultaneous significant rises in HR. During phase 2, HR and estimated power output (POapprox) produced at each of the four prescribed effort levels were significantly different (P<0.01). The children in this study were able to discriminate between 4 different exercise intensities and regulate their exercise intensity according to 4 prescribed levels of perceived exertion. In seeking to contribute towards children’s recommended physical activity levels and helping them understand how to self-regulate their activity, the application of the PCERT within the context of physical education is a desirable direction for future research

    Organic liquid mobility induced by smoldering remediation

    Get PDF
    Laboratory column experiments plus analytical and numerical modeling together suggest that, under certain conditions, downward organic liquid mobilization can occur and impact smoldering behavior. This applies for organic liquids mixed with inert sand subjected to smoldering as thermal treatment. The observed effects include increased peak temperatures (here by up to 35%) and increased treatment times (here by up to 30%). Downward organic liquid migration occurs when (i) injected Darcy air flux is less than a threshold value (here less than 3 cm/s), (ii) treatment systems are tall (here 90 cm, not 30 cm), and (iii) the organic liquid is temperature-sensitive (viscosity less than 0.01 Pa s at 150 °C). The developed analytical equation provides the applied air flux that can negate the downwards organic liquid gradient required for migration. Smoldering behavior is demonstrated to adjust to liquid migration and thereby still destroy all the organic waste in the system. Smoldering is a relatively new, energy-efficient thermal treatment for organic liquid waste and these results are important for designing field applications of smoldering treatment

    An integrated and coordinated approach to preventing recurrent coronary heart disease events in Australia: Policy statement from the Australian Cardiovascular Health and Rehabilitation Association

    Full text link
    • Implementing existing knowledge about cardiac rehabilitation (CR) and heart failure management could markedly reduce mortality after acute coronary syndromes and revascularisation therapy. • Contemporary CR and secondary prevention programs are cost-effective, safe and beneficial for patients of all ages, leading to improved survival, fewer revascularisation procedures and reduced rehospitalisation. • Despite the proven benefits attributed to these secondary prevention interventions, they are not well attended by patients. • Modern programs must be flexible, culturally safe, multifaceted and integrated with the patient's primary health care provider to achieve optimal and sustainable benefits for most patients

    Investigating the referral of patients with non-urgent conditions to a regional Australian emergency department: a study protocol

    Get PDF
    Background:Australia’s only island state, Tasmania, experiences one of the nation’s highest incidences of non-urgent emergency department (ED) presentations in a healthcare system regularly faced with service demands that exceed resource availability. Service-demand mismatches are acknowledged to contribute to ED crowding which in turn, has been documented to have a correlation with poorer patient outcomes. Crowding within EDs is complex, non-urgent presentations alone are not the primary cause, but have been reported to be a contributing factor. In 2015–16 Tasmania recorded over 153,000 ED attendances, 55% of these fell into the two least urgent triage categories. Recent research in the State’s North established that 29% of non-urgent presentations were referred, formally or informally, from primary healthcare providers and that, for many patients (39%), the ED was not their first choice of service provider. This study aims to identify the service needs of patients referred to a regional Australian ED and subsequently triaged as non-urgent.Method:In order to achieve this aim, three objectives have been identified. The first two objectives use an explanatory sequential mixed-method approach while the third objective will incorporate an implementation science approach. These three objectives are: first, a retrospective analysis of seven years of routinely collected hospital data to identify trends in referral of patients with non-urgent conditions; second, focus group interviews with patients and primary care providers to further understand perceived need and service requirements of those referred to the ED, and third, translation of findings into local health service recommendations.Discussion:Identification of the needs of patients referred to the ED with non-urgent conditions will inform future service planning aiming to facilitate access to the right service at the right time and in the right place

    A systematic review of school-based sexual health interventions to prevent STI/HIV in sub-Saharan Africa

    Get PDF
    Background The HIV/AIDS epidemic remains of global significance and there is a need to target (a) the adolescent age-groups in which most new infections occur; and (b) sub-Saharan Africa where the greatest burden of the epidemic lies. A focused systematic review of school-based sexual health interventions in sub-Saharan Africa to prevent HIV/AIDS and Sexually Transmitted Infections (STI) in this age group was therefore conducted. Methods Searches were conducted in Medline, Embase, Cinahl and PsychINFO according to agreed a priori criteria for studies published between 1986 and 2006. Further searches were conducted in UNAIDS and WHO (World Health Organization) websites, and 'Google'. Relevant journals were hand-searched and references cited in identified articles were followed up. Data extraction and quality assessment was carried out on studies selected for full text appraisal, and results were analysed and presented in narrative format. Results Some 1,020 possible titles and abstracts were found, 23 full text articles were critically appraised, and 12 articles (10 studies) reviewed, reflecting the paucity of published studies conducted relative to the magnitude of the HIV epidemic in sub-Saharan Africa. Knowledge and attitude-related outcomes were the most associated with statistically significant change. Behavioural intentions were more difficult to change and actual behaviour change was least likely to occur. Behaviour change in favour of abstinence and condom use appeared to be greatly influenced by pre-intervention sexual history. Conclusion There is a great need in sub-Saharan Africa for well-evaluated and effective school-based sexual health interventions
    • …
    corecore