Preliminary analysis of fuel tank impact

Following the accident involving the Air France Concorde in 2000 the effects of fluid structure interactions resulting from the impact of a fluid filled tank has become a cause for concern. The work reported here relates to the design of a series of experiments loosely based upon the Concorde incident which aimed to assess whether the probable failure mode in the Concorde accident could occur in land based vessels. Preliminary numerical analyses were undertaken for two of the nine cases that were investigated experimentally in which an empty tank was impacted by a projectile with a velocity of 14m/s and 21.9m/s Initial numerical results for the acceleration at two points on the tank surface and the deformation at the impact zone showed good agreement with test data. Future work is discussed including further numerical modelling incorporating fluid structure interactions for the analysis of the cases when the tank is partially full or completely full

Burn-Out Among Social Work Professionals: A Behavioral Approach to Causal and Interventive Knowledge

Although the phenomenon of staff burn-out represents a significant problem for the effective administration and functioning of social service settings, there has been a general paucity of empirically based research on this issue. The staggering financial, personal and social costs associated with staff burn-out emphasize the fact that we can no longer accept the sole use of descriptive and correlational studies of the problem. This paper suggests refocusing our theoretical perspective of the problem of staff burn-out from an emphasis on the dispositional qualities of burnedout staff members, to examining the social and situational contingencies of reinforcement responsible for the acquisition and maintenance of burnout. In addition, this paper discusses the application of experimental methodologies designed to identify causative factors and evaluate interventive procedures. It is believed that this approach will facilitate our understanding of the causes of burn-out and assist in developing effective interventive procedures

Serving the Homeless: Evaluating the Effectiveness of Homeless Shelter Services

The effects of homeless assistance services at the local level are tremendously difficult to ascertain. In this study, a four-month sample of homeless persons served by a local homeless shelter and case management program were contacted nine to eleven months after receiving services. The findings suggest that the program had some initial success in assisting the homeless clients to locate housing within the first year after leaving the shelter. However, the housing costs paid by these formerly homeless were quite high, with nearly three-quarters of them spending forty percent or more of their income on housing

Does wilderness therapy reduce recidivism in delinquent adolescents?: A narrative review

Adolescent recidivism rates remain high in the United States despite the fact juvenile crime has declined since the 1990’s. Wilderness therapy (WT) is an emerging treatment approach for adolescents involved in the juvenile justice system. This review examines outcome studies utilizing a wilderness therapy program in an effort to reduce adolescent recidivism. Studies were eligible if they: (a) evaluated a WT intervention, (b) utilized an adolescent population, (c) included a measure of recidivism as an outcome variable, and were (d) published in English between 1990 and June of 2010 in a peer-reviewed journal. A total of seven studies on WT were included, and the majority of studies indicated mildly positive short-term results though long-term effects were mixed. The overall quality of the evaluations designs was low, indicating the need for better controlled and longer term experimental evaluations

The determinants of household water consumption: A review and assessment framework for research and practice

Achieving a thorough understanding of the determinants of household water consumption is crucial to support demand management strategies. Yet, existing research on household water consumption determinants is often limited to specific case studies, with findings that are difficult to generalize and not conclusive. Here, we first contribute an updated framework for review, classification, and analysis of the literature on the determinants of household water consumption. Our framework allows trade-off analysis of different criteria that account for the representation of a potential water consumption determinant in the literature, its impact across heterogeneous case studies, and the effort required to collect information on it. We then review a comprehensive set of 48 publications with our proposed framework. The results of our trade-off analysis show that distinct groups of determinants exist, allowing for the formulation of recommendations for practitioners and researchers on which determinants to consider in practice and prioritize in future research

Evaluating the benefits of smart stormwater systems: summary of research outcomes

There is significant promise for the use of smart, distributed stormwater storage for addressing a range of challenges associated with integrated urban water management, includingFlood control via peak flow reductions and/or reduced infrastructure costsWater for urban greening and coolingImproving the quality of receiving waters.This study assessed the benefits and costs of a range of stormwater storage options, including smart operation, for urban stormwater systems The benefits assessed include peak overland flow reduction, water re-use potential and water quality impacts. Results were compared with more traditionally used pipe upgrades. The case study catchment was located in the City of Unley, Adelaide, South Australia. The key conclusions were:Passive distributed storages optimised using machine learning achieves similar peak flow reduction as end-of-system storage with reduced storage size and cost and is easier to implement. Cost savings were 30%-44% compared to an equivalent pipe upgradeSmart distributed storage with ‘before storm control’ achieves a similar peak flow reduction at similar cost as pipe upgrade with additional water reuse and water quality benefits Cost and peak flow reductions were similar to an equivalent pipe upgrade of approx. 550m to 700m length with the additional benefits of potential water reuse volume of 3.1 ML/year and water quality benefits with reduced total suspended solids (51%), phosphorus (27%) and nitrogen (9%).Smart distributed storages with ‘during storm’ real-time control provide significant potential for additional peak flow reductions or cost savings through storage size reductions. Further development is required for this technology to be used in practice.Machine learning / artificial intelligence optimisation methods played an essential role for identifying the optimal location, sizing and operating rules for the distributed storage options. Due to the high number of potential locations, sizes and operating rules a traditional trial and error design approach would be far slower and unlikely to achieve a similar outcome.Mark Thyer, Holger Maier, Michael DiMatte

A virtual hydrological framework for evaluation of stochastic rainfall models

Stochastic rainfall modelling is a commonly used technique for evaluating the impact of flooding, drought, or climate change in a catchment. While considerable attention has been given to the development of stochastic rainfall models (SRMs), significantly less attention has been paid to developing methods to evaluate their performance. Typical evaluation methods employ a wide range of rainfall statistics. However, they give limited understanding about which rainfall statistical characteristics are most important for reliable streamflow prediction. To address this issue a formal evaluation framework is introduced, with three key features: (i) streamflow-based, to give a direct evaluation of modelled streamflow performance, (ii) virtual, to avoid the issue of confounding errors in hydrological models or data, and (iii) targeted, to isolate the source of errors according to specific sites and seasons. The virtual hydrological evaluation framework uses two types of tests, integrated tests and unit tests, to attribute deficiencies that impact on streamflow to their original source in the SRM according to site and season. The framework is applied to a case study of 22 sites in South Australia with a strong seasonal cycle. In this case study, the framework demonstrated the surprising result that apparently “good” modelled rainfall can produce “poor” streamflow predictions, whilst “poor” modelled rainfall may lead to “good” streamflow predictions. This is due to the representation of highly seasonal catchment processes within the hydrological model that can dampen or amplify rainfall errors when converted to streamflow. The framework identified the importance of rainfall in the “wetting-up” months (months where the rainfall is high but streamflow low) of the annual hydrologic cycle (May and June in this case study) for providing reliable predictions of streamflow over the entire year despite their low monthly flow volume. This insight would not have been found using existing methods and highlights the importance of the virtual hydrological evaluation framework for SRM evaluation.Bree Bennett, Mark Thyer, Michael Leonard, Martin Lambert and Bryson Bate

A comprehensive and systematic evaluation framework for a parsimonious daily rainfall field model

The spatial distribution of rainfall has a significant influence on catchment dynamics and the generation of streamflow time series. However, there are few stochastic models that can simulate long sequences of stochastic rainfall fields continuously in time and space. To address this issue, the first goal of this study was to present a new parsimonious stochastic model that produces daily rainfall fields across the catchment. To achieve parsimony, the model used the latent-variable approach (because this parsimoniously simulates rainfall occurrences as well as amounts) and several other assumptions (including contemporaneous and separable spatiotemporal covariance structures). The second goal was to develop a comprehensive and systematic evaluation (CASE) framework to identify model strengths and weaknesses. This included quantitative performance categorisation that provided a systematic, succinct and transparent method to assess and summarise model performance over a range of statistics, sites, scales and seasons. The model is demonstrated using a case study from the Onkaparinga catchment in South Australia. The model showed many strengths in reproducing the observed rainfall characteristics with the majority of statistics classified as either statistically indistinguishable from the observed or within 5% of the observed across the majority of sites and seasons. These included rainfall occurrences/amounts, wet/dry spell distributions, annual volumes/extremes and spatial patterns, which are important from a hydrological perspective. One of the few weaknesses of the model was that the total annual rainfall in dry years (lower 5%) was overestimated by 15% on average over all sites. An advantage of the CASE framework was that it was able to identify the source of this overestimation was poor representation of the annual variability of rainfall occurrences. Given the strengths of this continuous daily rainfall field model it has a range of potential hydrological applications, including drought and flood risk.Bree Bennett, Mark Thyer, Michael Leonard, Martin Lambert, Bryson Bate

Pitfalls and improvements in the joint inference of heteroscedasticity and autocorrelation in hydrological model calibration

Residual errors of hydrological models are usually both heteroscedastic and autocorrelated. However, only a few studies have attempted to explicitly include these two statistical properties into the residual error model and jointly infer them with the hydrological model parameters. This technical note shows that applying autoregressive error models to raw heteroscedastic residuals, as done in some recent studies, can lead to unstable error models with poor predictive performance. This instability can be avoided by applying the autoregressive process to standardized residuals. The theoretical analysis is supported by empirical findings in three hydrologically distinct catchments. The case studies also highlight strong interactions between the parameters of autoregressive residual error models and the water balance parameters of the hydrological model. ©2013. American Geophysical Union. All Rights Reserved.Guillaume Evin, Dmitri Kavetski, Mark Thyer, and George Kuczer