583 research outputs found

    Water jet/spray measurement analysis

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    The objective of this study was to provide analysis of data obtained under a previous contract entitled Characterization of Drop Spectra from High Volume Flow Water Jets. Measurements of drop spectra were obtained in the spray resulting from the breakup of high volume flow water jets from a variety of nozzle types. The drop spectra measurements were obtained from two drop spectrometers covering a range from 10 microns to 12 millimeters diameter. The task addressed was to select representative spectra from the individual tests and provide analyses in both numerical and graphical formats as outlined in the proposal. The intended application of these results is an evaluation of the feasibility of fog clearing by high volume water sprays. During the tests, a fog event occurred making it possible to test the concept of fog clearing. Visual range data and fog drop spectra were analyzed, with particular emphasis placed on the modification of these parameters due to the water spray

    Position paper on the potential of inadvertent weather modification of the Florida Peninsula resulting from neutralization of space shuttle solid rocket booster exhaust clouds

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    A concept of injecting compounds into the exhaust cloud was proposed to neutralize the acidic nature of the low-level stabilized ground cloud (SGC) was studied. The potential Inadvertent Weather Modification caused by exhaust cloud characteristics from three hours to seven days after launch was studied. Possible effects of the neutralized SGC in warm and cloud precipitation processes were discussed. Based on a detailed climatology of the Florida Peninsula, the risk for weather modification under a variety of weather situations was assessed

    Position paper on the potential of inadvertent weather modification of the Florida peninsula resulting from the stabilized ground cloud

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    Based on the climatology of the Florida Peninsula, we assessed the risk for weather modification. Certain weather situations warrant launch rescheduling because of the risk of possible impact on hurricanes, hail formation and lightning activity, strong wind developments, and intensification of high rainfall rates. The cumulative effects of 40 launches per year on weather modification were found to be insignificant

    Factors that influence delivery of tobacco cessation support in general dental practice: A narrative review

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    Objectives: To review the literature reporting factors that are associated with the delivery of lifestyle support in general dental practice. Methods: A systematic review of the quantitative observational studies describing activities to promote the general health of adults in primary care general dental practice. Behaviour change included tobacco cessation, alcohol reduction, diet, weight management and physical activity. Tooth brushing and oral hygiene behaviours were excluded as the focus of this review was on the common risk factors that affect general health as well as oral health. Results: Six cross sectional studies met the inclusion criteria. Five studies only reported activities to support tobacco cessation. As well as tobacco cessation one study also reported activities related to alcohol usage, physical activity and Body Mass Index. Perceptions of time availability consistently correlated with activities and beliefs about tobacco cessation, alongside the smoking status of the dental professional. Dentists who perceive having more available time were more likely to discuss smoking with patients, prescribe smoking cessation treatments and direct patients towards (signpost to) lifestyle support services. Dental professionals who smoke were less likely to give smoking cessation advice and counselling than non-smokers. Finally, the data showed that professional support may be relevant. Professionals who work in solo practices or those who felt a lack of support from the wider professional team (peer support) were more likely to report barriers to delivering lifestyle support. Conclusion: Organisational changes in dental practices to encourage more team working and professional time for lifestyle support may influence delivery. Dental professionals who are smokers may require training to develop their beliefs about the effectiveness of smoking cessation interventions

    New Technologies, New Identities, and the Growth of Mass Opposition in the Arab Spring

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    The recent revolutions known as the Arab Spring have been characterized as the products of social media. However, there is an alternative view that revolution takes place on the street or the battlefield and that the role of social media has been overstated. We argue that some new technologies can serve to facilitate rapid social change when they provide ways to overcome restrictions on the freedoms of expression and association. In doing so, communication technologies enable the formation of new social identities that can challenge existing social orders by promoting the growth of a social movement that is positioned as loyal to the nation and its people but opposed to the government. Our analyses focus on the role of social media in spreading video images of dissent and the links between this video material, satellite television, and mobile telephones in Tunisia and Egypt

    Messages of hope: Using positive stories of survival to assist recovery in Rwanda

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    For the past twenty years, the overriding story of Rwanda has been centred around the events and consequences of the genocide. In Rwanda, public expressions of that story have occurred in the gacaca courts, where survivors and perpetrators testified about their experiences and actions, during ongoing annual remembrance and mourning commemorations, and in memorial sites across the country that act as physical reminders of the genocide. While important as mechanisms for justice, testimony, and commemoration, on their own such events and installations also have the potential to re-traumatise. Accordingly, Rwandan agencies have encouraged a focus on the future as the overarching theme of recent national commemorations. Yet, opportunities for Rwandans to recount and disseminate positive, future-oriented stories of survival and healing remain sparse. Creation and awareness of positive stories have the potential to assist in recovery by increasing feelings of hope and efficacy; and recent research has demonstrated the value of hopefulness, well-being, and social support for vulnerable people. The Messages of Hope program seeks to leverage those ideas into a framework for generating positive messages by Rwandan survivors, providing an opportunity for everyday Rwandans to record and transmit their own positive stories of survival to demonstrate recovery and growth after the genocide, and to reinforce connectedness by sharing their challenges and aspirations. We describe the development and early implementation of this initiative and its potential longer-term application in other contexts of vulnerability

    Phase transition and scaling behavior of topological charged black holes in Horava-Lifshitz gravity

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    Gravity can be thought as an emergent phenomenon and it has a nice "thermodynamic" structure. In this context, it is then possible to study the thermodynamics without knowing the details of the underlying microscopic degrees of freedom. Here, based on the ordinary thermodynamics, we investigate the phase transition of the static, spherically symmetric charged black hole solution with arbitrary scalar curvature 2k2k in Ho\v{r}ava-Lifshitz gravity at the Lifshitz point z=3z=3. The analysis is done using the canonical ensemble frame work; i.e. the charge is kept fixed. We find (a) for both k=0k=0 and k=1k=1, there is no phase transition, (b) while k=−1k=-1 case exhibits the second order phase transition within the {\it physical region} of the black hole. The critical point of second order phase transition is obtained by the divergence of the heat capacity at constant charge. Near the critical point, we find the various critical exponents. It is also observed that they satisfy the usual thermodynamic scaling laws.Comment: Minor corrections, refs. added, to appear in Class. Quant. Grav. arXiv admin note: text overlap with arXiv:1111.0973 by other author
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