Behaviour of moist and saturated sand during shock and release

Relatively little is known about the changes that occur in the shock compaction and release of granular matter with varying levels of moisture. Here, we report a series of plate impact experiments giving shock Hugoniot and release data for a well characterized sand at dry, 10% moist and saturated water contents. The results reveal that at low moisture content the shock impedance is slightly reduced, while the release remains predominantly inelastic. Close to saturation, much more substantial changes occur: the shock impedance stiffens substantially, the Hugoniot appears to split into two branches, and the release becomes almost completely elastic. We discuss mechanisms underpinning these changes in behavior.This work was supported through the Force Protection Engineering research programme led by QinetiQ Plc. on behalf of DSTL.This is the author accepted manuscript. The final version is available from AIP via http://dx.doi.org/10.1063/1.493468

High Strain Rate Properties of Geological Materials

The dynamic response of various geological materials has been investigated through a series of plate impact experiments. The materials involved were supplied from various mines by De Beers and Rio Tinto and were generically termed: sandstone, scilified siltstone, kimberlite, quartz/feldspathic gneiss, biotite schist, amphibolite, amphibolitic gneiss, basalt and iron ore. Investigations into compressional, shear and tensional behaviour were carried out. This project was part of a larger international study to develop models for the explosive loading of rock in a mining environment. This model is known as the Hybrid Stress Blasting Model, or HSBM. For this model to be accurate and relevant to the mining process it is essential to have dynamic data on the various rock types concerned. This was the purpose of the current project. As the material data are destined for use in a computer modelling programme it was essential to attempt to develop prediction methodologies to avoid the need for expensive dynamic characterisation of any new materials encountered in the mining environment. Much of the static data provided with the materials from De Beers proved of little use in predicting behaviour, although crucially it was not possible to determine sufficient dynamic tensile strengths in this investigation to make comparisons with the De Beers data. More success was found in predicting the slope of the Hugoniot with the elastic impedance of the material (for the non-porous linear Hugoniot materials). A fairly strong trend was found, which was backed up with data from the literature. Additionally some effort at further analysis using mineral data was undertaken. Attempts at predicting the HEL were also partially successful. While no specific quantitative prediction method was found, it was noted that the HEL did seem to scale with grain size, in that the large grained materials had a lower value of the HEL (below 2 GPa) compared with the finer grained materials (around 4 GPa and above).De Beers and Pilbara Iron Company (a subsidiary of Rio Tinto

Motivational climate interventions in physical education: a meta-analysis

Objective: The purpose of this study was to synthesize findings from motivational climate interventions employing Ames (1992a, 1992b) and Epstein’s (1988, 1989) TARGET framework within school-based physical education contexts. Design: The present study employed a quantitative research synthesis design. Meta-analysis uses empirical studies to summarize past research by drawing overall conclusions from separate investigations. This research design highlights important and unsolved issues related to motivational climate interventions within physical education. Methods: Standard meta-analytic procedures incorporating inclusion and exclusion criteria, literature search, coding procedures, and statistical methods were used to identify and synthesize 22 studies with 24 independent samples. Cohen’s (1988) criteria for effect sizes were used to interpret and evaluate results. Results: There was an overall small positive treatment effect (g ¼ 0.103) for groups exposed to mastery motivational climates. Outcome analyses identified the most consistent and largest overall treatment effects for behavioral outcomes (g ¼ 0.39e0.49) followed by affective outcomes (g¼ 0.27 to 0.59) and cognitive outcomes (g¼ 0.25 to 0.32). Moderator analyses were directed by study heterogeneity and identified several trends in intervention features and study features with the most substantial trend for participant features as elementary students had the largest overall treatment effect (g¼ 0.41). Conclusions: Outcome and moderator analyses identified several trends in methodological features, participant features, and study features that should be addressed in future physical education motivational climate interventions

Black College Women Sexual Health Peer Education at Clark Atlanta University

Background: This research was based on the premise that various factors, such as social determinants, cultural competency, use of statistics and location, contribute to the efficacy of the transmission of sexual health education. In the United States, African American women account for 60% of the cases of human immunodeficiency virus (HIV) of women. Considerable research has noted the high rates of HIV among African-American women. The present research, however, focused exclusively on Black college women at Clark Atlanta University (CAU). Methods: A mixed method approach using surveys and participant observation in an exploratory case study was used to evaluate responses of Black college women at CAU to sexual health peer education. Results: Most of the Black college women who attended an event sponsored by Health Services, the Health Peers Educating and Encouraging Responsible Students (H-PEERS), reported that it effectively impacted their overall sexual health. Conclusions: Although, the female students reported having prior knowledge of sexual health information prior to attending CAU, including risk reduction behaviors, they reported participating in sexual risky behaviors. Many of the female students whom reported attending an event sponsored by the H-PEERS effectively had an impact on their sexual health knowledge, attitudes and beliefs towards sex, sexual behaviors, and sexual health status. Further research is needed on how the overall sexual health of black college women at Historically Black Colleges and Universities (HBCU) and predominantly white schools (PWI), and how strategies, such as peer-led health education, differ in transmission and efficacy

Using behavioral science to promote international development

https://issuu.com/behavioralsciencepolicyassociation/docs/v3i3_web_bryanhttps://issuu.com/behavioralsciencepolicyassociation/docs/v3i3_web_bryanhttps://issuu.com/behavioralsciencepolicyassociation/docs/v3i3_web_bryanhttps://issuu.com/behavioralsciencepolicyassociation/docs/v3i3_web_bryanhttps://issuu.com/behavioralsciencepolicyassociation/docs/v3i3_web_bryanhttps://issuu.com/behavioralsciencepolicyassociation/docs/v3i3_web_bryanAccepted manuscrip

Averting HIV Infections in New York City: A Modeling Approach Estimating the Future Impact of Additional Behavioral and Biomedical HIV Prevention Strategies

Background:New York City (NYC) remains an epicenter of the HIV epidemic in the United States. Given the variety of evidence-based HIV prevention strategies available and the significant resources required to implement each of them, comparative studies are needed to identify how to maximize the number of HIV cases prevented most economically.Methods:A new model of HIV disease transmission was developed integrating information from a previously validated micro-simulation HIV disease progression model. Specification and parameterization of the model and its inputs, including the intervention portfolio, intervention effects and costs were conducted through a collaborative process between the academic modeling team and the NYC Department of Health and Mental Hygiene. The model projects the impact of different prevention strategies, or portfolios of prevention strategies, on the HIV epidemic in NYC.Results:Ten unique interventions were able to provide a prevention benefit at an annual program cost of less than $360,000, the threshold for consideration as a cost-saving intervention (because of offsets by future HIV treatment costs averted). An optimized portfolio of these specific interventions could result in up to a 34$106,378; the total cost was in excess of $2 billion (over the 20 year period, or approximately$100 million per year, on average). The cost-savings of prevented infections was estimated at more than $5 billion (or approximately$250 million per year, on average).Conclusions:Optimal implementation of a portfolio of evidence-based interventions can have a substantial, favorable impact on the ongoing HIV epidemic in NYC and provide future cost-saving despite significant initial costs. © 2013 Kessler et al

Problems Associated with Making Mechanical Measurements on Water–Ice at Quasistatic and Dynamic Strain Rates

Abstract: Space penetrators are a potential method of inserting instrumentation onto ice-covered bodies in the solar system. Part of a study to see whether this is feasible involves numerically simulating impact of the penetrator into ice at impact velocities of a few 100 m/s. In order to do this accurately, it is necessary to have a constitutive model for water ice that is valid at the strain rates and temperatures relevant to impact in the Outer Solar System. This paper reports certain issues and difficulties that arose during a study to obtain this data

The “Haunt” project: An attempt to build a “haunted” room by manipulating complex electromagnetic fields and infrasound

Recent research has suggested that a number of environmental factors may be associated with a tendency for susceptible individuals to report mildly anomalous sensations typically associated with “haunted” locations, including a sense of presence, feeling dizzy, inexplicable smells, and so on. Factors that may be associated with such sensations include fluctuations in the electromagnetic field and the presence of infrasound. A review of such work is presented, followed by the results of the “Haunt” project in which an attempt was made to construct an artificial “haunted” room by systematically varying such environmental factors. Participants (N = 79) were required to spend 50 minutes in a specially constructed chamber, within which they were exposed to infrasound, complex electromagnetic fields, both or neither. They were informed in advance that during this period they might experience anomalous sensations and asked to record on a floor-plan their location at the time occurrence of any such sensations, along with a note of the time of occurrence and a brief description of the sensation. Upon completing the session in the experimental chamber, they were asked to complete three questionnaires. The first was an EXIT scale asking respondents to indicate whether or not they had experienced particular anomalous sensations. The second was the Australian Sheep-Goat Scale, a widely used measure of belief in and experience of the paranormal. The third was Persinger’s Personal Philosophy Inventory, although only the items that constitute the Temporal Lobe Signs Inventory (TLS) sub-scale were scored. These items deal with psychological experiences typically associated with temporal lobe epilepsy but normally distributed throughout the general population. Although many participants reported anomalous sensations of various kinds, the number reported was unrelated to experimental condition but was related to TLS scores. The most parsimonious explanation for our findings is in terms of suggestibility

A comparison of energy systems in Birmingham, UK, with Masdar City, an embryonic city in Abu Dhabi Emirate

AbstractEnergy is a vital resource in modern life. With increasingly limited availability of traditional energy resources, e.g., oil, coal and nuclear, together with environmental concerns, there is raised awareness that energy needs to be both used more efficiently and generated in line with thinking on sustainability. Ready access to ‘clean’ energy is essential if we wish to maintain our current way of life without compromising our wellbeing or the carrying capacity of the planet. This paper aims to analyse the differences and similarities in energy supply and demand between two very different cities. Masdar City, founded in 2008, is a dynamic new Middle-Eastern city being built in a desert environment. Its aim is to be the most sustainable city in the world and offers an exciting opportunity to provide unique insights into the application of different innovative technologies as ‘new-build’ within an urban environment. Birmingham is a well-established post-industrial city that has evolved over fourteen hundred years. It was one of the fastest growing cities in 19th century England (Popp and Wilson, 2009) [1]. To do this a material flow analysis approach has been adopted to provide a framework for the study. The energy-related opportunities and mutual benefits that each city can gain from the experiences of the other are explored and five emergent issues are identified: innovation and experimentation, lock-in, balance, resilience and governance. This work shows how a greater understanding of common issues can lead to more sustainable, resilient and robust cities, able to face the challenges of the next 50 years