http://ift.tt/2jGPHi3
Πέμπτη 2 Φεβρουαρίου 2017
Probabilistic aspect of fire whirl generation around an L-shaped fire source in a crosswind
Publication date: March 2017
Source:Fire Safety Journal, Volume 88
Author(s): Keisuke Himoto, Tomohiro Naruse
Fire whirls can be generated during large outdoor fires such as post-earthquake urban fires, and their consequences are often devastating. Therefore, when assessing the post-earthquake fire risk in urban areas, the conditions of fire whirls generation must be understood. There have been attempts to determine the critical crosswind velocity that maximizes the occurrence of fire whirls. However, it does not account for the substantially varying frequency of fire whirl generation among different cases. From a fire-risk perspective, steadily generated fire whirls need to be distinguished from intermittently generated ones, but such a distinction has not been attempted to date. In this study, the probabilistic aspect of fire whirl generation around an L-shaped gas burner in a crosswind was experimentally investigated in a wind tunnel. The test parameters were the heat release rate per unit length (32.5–86.8kW/m) and the crosswind velocity (0.115–0.696m/s). Fire whirl was observed in 10 out of 19 cases, but the duration period (i.e., frequency) of the fire whirl generation varied substantially among the cases. The variation of the generation frequency was successfully generalized by the Froude number, Fr, a characteristic value of the counter-flow around the fire source. The Strouhal number, St, which is often used to characterize periodic pulsation of buoyant diffusion flames, was also found to be an appropriate value characterizing the coherency within the unsteady fire whirl generation phenomena.
http://ift.tt/2k3agsr
Source:Fire Safety Journal, Volume 88
Author(s): Keisuke Himoto, Tomohiro Naruse
Fire whirls can be generated during large outdoor fires such as post-earthquake urban fires, and their consequences are often devastating. Therefore, when assessing the post-earthquake fire risk in urban areas, the conditions of fire whirls generation must be understood. There have been attempts to determine the critical crosswind velocity that maximizes the occurrence of fire whirls. However, it does not account for the substantially varying frequency of fire whirl generation among different cases. From a fire-risk perspective, steadily generated fire whirls need to be distinguished from intermittently generated ones, but such a distinction has not been attempted to date. In this study, the probabilistic aspect of fire whirl generation around an L-shaped gas burner in a crosswind was experimentally investigated in a wind tunnel. The test parameters were the heat release rate per unit length (32.5–86.8kW/m) and the crosswind velocity (0.115–0.696m/s). Fire whirl was observed in 10 out of 19 cases, but the duration period (i.e., frequency) of the fire whirl generation varied substantially among the cases. The variation of the generation frequency was successfully generalized by the Froude number, Fr, a characteristic value of the counter-flow around the fire source. The Strouhal number, St, which is often used to characterize periodic pulsation of buoyant diffusion flames, was also found to be an appropriate value characterizing the coherency within the unsteady fire whirl generation phenomena.
http://ift.tt/2k3agsr
Scaling of wood pallet fires
Publication date: March 2017
Source:Fire Safety Journal, Volume 88
Author(s): Ying Zhen Li, Haukur Ingason
A method for scaling time-resolved burning behaviors of wood pallet fires has been developed. A series of validation tests was carried out in two different scales and the time-resolved heat release rates were obtained and compared. The results show that the scaling method proposed works very well. The scaling method proposed could be applied to general wood pallets.
http://ift.tt/2jGF5Ql
Source:Fire Safety Journal, Volume 88
Author(s): Ying Zhen Li, Haukur Ingason
A method for scaling time-resolved burning behaviors of wood pallet fires has been developed. A series of validation tests was carried out in two different scales and the time-resolved heat release rates were obtained and compared. The results show that the scaling method proposed works very well. The scaling method proposed could be applied to general wood pallets.
http://ift.tt/2jGF5Ql
Τετάρτη 1 Φεβρουαρίου 2017
Survival following lung transplantation for artificial stone silicosis relative to idiopathic pulmonary fibrosis
Abstract
Background
Silicosis is a progressive lung disease resulting from the inhalation of respirable crystalline silica. Lung transplantation is the only treatment for end-stage silicosis. The aim of this study was to analyze the survival experience following lung transplantation among patients with silicosis.
Methods
We reviewed data for all patients who underwent lung transplantation for silicosis and a matched group undergoing lung transplantation for idiopathic pulmonary fibrosis (IPF) at a single medical center between March 2006 and the end of December 2013. Survival was followed through 2015.
Results
A total of 17 lung transplantations were performed for silicosis among 342 lung transplantations (4.9%) during the study period. We observed non-statistically significant survival advantage (hazard ratio 0.6; 95%CI 0.24–1.55) for those undergoing lung transplantation for silicosis relative to IPF patients undergoing lung transplantation during the same period.
Conclusions
Within the limits of a small sample, survival in silicosis patients following lung transplantation was not reduced compared to IPF. Am. J. Ind. Med. 9999:1–7, 2016. © 2016 Wiley Periodicals, Inc.
http://ift.tt/2jWe12W
Workers’ compensation claims not reported in the Survey of Occupational Injuries and Illnesses: Injury and claim characteristics
Background
Underreporting in the nation's primary source of non-fatal occupational injury and illness data are well documented, but worker-level characteristics of unreported cases have not been fully explored.
Methods
Bureau of Labor Statistics’ Survey of Occupational Injuries and Illnesses (SOII) data were linked to Washington workers’ compensation claims to identify injury and claim characteristics associated with unreported cases. Workers’ compensation administrative date data were used to characterize timing of disability and SOII case eligibility.
Results
Based on claim date data, one in five lost time claims with an injury date in the survey year were likely ineligible for SOII case reporting during the survey year. Among SOII-eligible claims, those involving sprains or strains, employer protests, and those not eligible for work disability payments until months after the initial injury were least likely to be reported in SOII.
Conclusions
SOII case capture is limited both by its cross sectional survey design and employer underreporting. Am. J. Ind. Med. 9999:XX–XX, © 2016 Wiley Periodicals, Inc.
http://ift.tt/2kUBnDS
Pulmonary adenocarcinoma with epidermal growth factor receptor-mutations in asbestos exposed non-smokers: A case series
Background
Cigarette smoke and asbestos are recognized causes of lung carcinoma and together promote carcinogenesis. Adenocarcinoma is currently the most common cause of lung cancer in the USA and it has been linked to both smoking and asbestos exposure. Mutations in the epidermal growth factor gene receptor (EGFR) occur predominantly in non-smokers with adenocarcinoma.
Methods Mutations in the EGFR gene were investigated using next-generation sequencing.
Results
We report the presence of EGFR exon point mutations in the pulmonary adenocarcinomas of three never-smokers occupationally exposed to asbestos.
Conclusion
The role of asbestos as a possible cause of EGFR mutagenesis requires further investigation. Am. J. Ind. Med. © 2017 Wiley Periodicals, Inc.
http://ift.tt/2jWd76M
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