Smouldering Remediation: Transient Effects of Front Propagation

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

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

Hospital length of stay variation and comorbidity of mental illness: A retrospective study of five common chronic medical conditions

Background: With the increasing burden of mental illness globally, it is becoming common for hospitalised patients with chronic medical conditions to have a comorbidity of mental illness. This combination could prolong length of stay (LOS) of this patient cohort. We conducted an investigation in Tasmania, Australian hospitals to characterise this cohort and assess if co-morbidity of mental illness is a distinguishing factor that generates LOS variation across different chronic medical conditions. Methods: The retrospective study analysed 16,898 admissions of patients with a primary diagnosis of one of five chronic medical conditions: lung or colorectal cancer, chronic obstructive pulmonary disease (COPD), type II diabetes, ischaemic heart disease (IHD) and stroke. Data were from July 2010 to June 2015, across four hospitals that collectively cover 95% of public hospital admissions in Tasmania, Australia. Descriptive statistics were used to compare characteristics of patients between the scenarios of with and without co-morbidity of mental illness. We used negative binomial regression models to assess whether co-morbidity of mental illness, along with its sub-types, after adjustment for potential confounding variables, associated with LOS variation in patients of each medical condition. Based on the adjusted LOS variation, we estimated differences in bed days' use between patients with and without comorbidity of mental illness. Results: Patients with co-morbidity of mental illness were significantly younger in comparison to patients without mental illness. With each medical condition, patients with comorbidity of mental illness had incurred higher bed days' use than for those without mental illness. In cancer and stroke cohorts, co-morbidity of mental illness unfavourably affected the LOS variation by as high as 97% (CI: 49.9%-159%) and 109% (78%-146%), respectively. Though mental and behavioural disorders due to psychoactive substances was a dominant sub-type of mental illness across the medical conditions, it contributed significant unfavourable LOS variation only in the stroke patients i.e. 36.3% (CI: 16.2%-59.9%). Conclusions: Mental illness consistently produced unfavourable LOS variation. Upskilling of healthcare teams and greater reporting and analysis of LOS variation for this patient cohort, and the sub-cohorts within it, are necessary to provide improved medical care and achieve system efficiencies

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

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

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

Fuel mobility dynamics and their influence on applied smouldering systems

Many recent environmentally beneficial applications of smouldering treat hazardous organic liquid fuels in inert porous media. In these applications, organic liquid mobilization can affect the treatment process, and the dynamics are poorly understood. Organic liquid mobilization is therefore a key knowledge gap that hinders the optimization of applied smouldering. This is especially the case in large scales where mobilization appears to be more significant. Liquid mobilization inside a porous medium cannot be easily measured directly, therefore numerical modelling is essential to understand the fundamental processes and to clarify the effects and dynamics of the fuel mobilization on the smouldering reaction. Contrasting numerical models with experimental temperature measurements have revealed many aspects of smouldering that cannot be measured. In this study, a previously developed 1D smouldering model was equipped with multiphase flow equations and compared against laboratory column experiments. The combination of model and experiments has served to quantify the dynamics of organic liquid fuel mobility by simulating high (i.e., non-mobile) and low (i.e., mobile) viscous fuels. The findings from this study shed light on the complicated interplay between multiphase flow, heat and mass transfer, and smoulder chemistry common to many applied smouldering systems. Numerical results confirmed that increasing the viscosity results in fuel remaining in the reaction zone and led to an increase in the peak temperature and smouldering front velocities. Lower viscosity fuels mobilized away from the reaction zone, thereby accumulating fuel in the pre-heating zone of the reactor. The fundamental understanding generated from this research will improve the design, implementation, and optimization of smouldering-based technologies for environmentally beneficial applications worldwide

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

• 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

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