64 research outputs found

    The requirements and challenges in preventing of road traffic injury in Iran. A qualitative study

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    <p>Abstract</p> <p>Background</p> <p>Road traffic injuries (RTIs) are a major public health problem, especially in low- and middle-income countries. Among middle-income countries, Iran has one of the highest mortality rates from RTIs. Action is critical to combat this major public health problem. Stakeholders involved in RTI control are of key importance and their perceptions of barriers and facilitators are a vital source of knowledge. The aim of this study was to explore barriers to the prevention of RTIs and provide appropriate suggestions for prevention, based on the perceptions of stakeholders, victims and road-users as regards RTIs.</p> <p>Methods</p> <p>Thirty-eight semi-structured interviews were conducted with informants in the field of RTI prevention including: police officers; public health professionals; experts from the road administrators; representatives from the General Governor, the car industry, firefighters; experts from Emergency Medical Service and the Red Crescent; and some motorcyclists and car drivers as well as victims of RTIs. A qualitative approach using grounded theory method was employed to analyze the material gathered.</p> <p>Results</p> <p>The core variable was identified as "The lack of a system approach to road-user safety". The following barriers in relation to RTI prevention were identified as: human factors; transportation system; and organizational coordination. Suggestions for improvement included education (for the general public and targeted group training), more effective legislation, more rigorous law enforcement, improved engineering in road infrastructure, and an integrated organization to supervise and coordinate preventive activities.</p> <p>Conclusion</p> <p>The major barriers identified in this study were human factors and efforts to change human behaviour were suggested by means of public education campaigns and stricter law enforcement. However, the lack of a system approach to RTI prevention was also an important concern. There is an urgent need for both an integrated system to coordinate RTI activities and prevention and a major change in stakeholders' attitudes towards RTI prevention. The focus of all activities should take place on road users' safety.</p

    Temperature dependence in the multiphoton dissociation of sulfur-32 hexafluoride

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    The multiphoton dissocn. of 32SF6 at 10.59 mm was studied as a function of temp. between 223 and 413 K. The obsd. decrease of the reaction yield with increasing temp. varied strongly with the laser energy fluence at the applied conditions. Rate consts. for the unimol. decompn. of SF6 induced by the monochromatic IR radiation were calcd. at 223, 293, and 343 K

    Infrared multiphoton energy deposition in chlorodifluoromethane

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    Energy absorption by CF2HCl from an intense CO2 laser pulse was measured as a function of the laser energy fluence, the temp., the pressure of CF2HCl, and the pressure of Ar bath gas. For collision-free multiphoton absorption, the av. no. of photons absorbed per mol. increases from 2 to nearly 12 when the fluence is increased from 1.6 to 10.9 J-cm-2 at 298 K. Compariosn of absorption and dissocn. data measured under identical conditions indicates relatively wide internal energy distributions produced by the multiphoton excitation. At 3 J-cm-2 the av. no. of photons absorbed per mol. increases with increasing temp. between 300 and 450 K, whereas in the same temp. range at 10.7 J-cm-2, a pronounced max. was found in the absorption near 370 K. In the presence of 1 atm of added Ar, an av. of as many as 100 photons per mol. of CF2HCl can be absorbed as compared to the 18 photons necessary for collisionless dissocn

    An investigation of laser intensity and temperature effects in the time-resolved infrared multiphoton dissociation of chlorodifluoromethane

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    The abs. :CF2 concn. is measured in situ and in real time by UV-absorption spectroscopy in the IR multiphoton dissocn. of CF2HCl during and after the laser pulse. The :CF2 prodn. rate is measured as a function of the laser intensity and the temp. at 9.17 mm. This rate increases with the IR intensity and temp. for nearly the whole range of conditions applied. At the highest temps. attained the :CF2 prodn. rates start to decrease with increasing temp

    Competition between collisions and optical pumping in unimolecular reactions induced by monochromatic infrared radiation

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    The optical pumping process in IR multiphoton induced unimol. reactions was studied by measuring the pressure dependence of the reaction yield as a function of the laser energy fluence and pulse shape. The dissocn. of SF6 is taken as a model reaction. Rate consts. for optical pumping near the reaction threshold were directly proportional to the laser intensity for the range of conditions applied

    Time-resolved measurement of difluoromethylene radical formation in the infrared multiphoton dissociation of chlorodifluoromethane

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    The IR multiphonon dissocn. of CF2HCl was investigated by monitoring the appearance of the CF2 product in real time during and after the laser pulse. The difluorcarbene radicals were detected quant. by their optical absorption in the ~A1B1->~X1A1 band system around 250 nm. The fragmentation was studied under collision-free conditions as well as in the presence of up to 500 torr Ar
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