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71.
Samuel L. Manzello Seul-Hyun Park Sayaka SuzukiJohn R. Shields Yoshihiko Hayashi 《Fire Safety Journal》2011,46(8):568-578
Attempting to experimentally quantify the vulnerabilities of structures to ignition from firebrand showers has remained elusive. The coupling of two facilities has begun to unravel this difficult problem. The NIST Firebrand Generator (NIST Dragon) is an experimental device that can generate a firebrand shower in a safe and repeatable fashion. Since wind plays a critical role in the spread of WUI fires in the USA and urban fires in Japan, NIST has established collaboration with the Building Research Institute (BRI) in Japan. BRI maintains one of the only full scale wind tunnel facilities in the world designed specifically for fire experimentation; the Fire Research Wind Tunnel Facility (FRWTF). The present investigation is aimed at extensively quantifying firebrand penetration through building vents using full scale tests. A structure was placed inside the FRWTF and firebrand showers were directed at the structure using the NIST Dragon. The structure was fitted with a generic building vent, consisting of only a frame fitted with a metal mesh. Six different mesh sizes openings were used for testing. Behind the mesh, four different materials were placed to ascertain whether the firebrands that were able to penetrate the building mesh assembly could ignite these materials. Reduced scale test methods afford the capability to test new vent technologies and may serve as the basis for new standard testing methodologies. As a result, a new experimental facility developed at NIST is presented and is known as the NIST Dragon's LAIR (Lofting and Ignition Research). The NIST Dragon's LAIR has been developed to simulate a wind driven firebrand attack at reduced scale. The facility consists of a reduced scale Firebrand Generator (Baby Dragon) coupled to a bench scale wind tunnel. Finally, a series of full scale experiments were conducted to visualize the flow of firebrands around obstacles placed downstream of the NIST Dragon. Firebrands were observed to accumulate in front of these obstacles at a stagnation plane, as was observed when the structure was used for firebrand penetration through building vent experiments, due to flow recirculation. The accumulation of firebrands at a stagnation plane presents a severe threat to ignitable materials placed near structures. 相似文献
72.
M LeBeau W Andollo WL Hearn R Baselt E Cone B Finkle D Fraser A Jenkins J Mayer A Negrusz A Poklis HC Walls L Raymon M Robertson J Saady 《Canadian Metallurgical Quarterly》1999,44(1):227-230
The recent increase in reports of drug-facilitated sexual assaults has caused alarm in the general public and prompted forensic toxicologists from across North America to address the toxicological issues surrounding this matter. The authors have developed recommendations and guidelines to inform law enforcement, medical, and scientific personnel of the requirements for performing successful toxicological examinations in cases of drug-facilitated rape. 相似文献
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F De Fine Olivarius J Lock-Andersen FG Larsen HC Wulf J Crosby M Norval 《Canadian Metallurgical Quarterly》1998,138(6):986-992
Urocanic acid (UCA) is a major chromophore for ultraviolet (UV) radiation in the skin. On UV exposure, the naturally occurring trans-isomer converts to the cis-isomer in a dose-dependent manner. Accumulating evidence indicates that cis-UCA acts as an initiator of the UV-induced suppression of certain skin immune functions. This immunomodulation is recognized as an important factor in the development of skin cancer. In this study, pigmentation and UCA isomers were measured in 29 patients with previous basal cell carcinoma (BCC), 23 patients with previous cutaneous malignant melanoma (MM), and 32 healthy controls. Measurements were performed on UV-exposed (forehead, upper back) and UV non-exposed (buttock) skin. No significant differences in pigmentation percentage, total UCA concentration, relative (%) or absolute (nmol/cm2) cis-UCA concentration were observed between the groups in any of the body sites studied. The net production of cis-UCA after irradiation with a single test UV dose was evaluated. The relative production of cis-UCA following irradiation was significantly higher in both cancer groups when compared with the control group, while no significant difference was found between the BCC and the MM patients. 相似文献
76.
HC Thomas MW Lamé SK Dunston HJ Segall DW Wilson 《Canadian Metallurgical Quarterly》1998,151(2):236-244
Eosinophilic myocarditis followed by fibrosis of the cardiac muscle was observed in addition to peripheral blood eosinophilia in CBA/J mice infected with Toxocara canis. The infected mice were used as an experimental model of eosinophilic endomyocarditis associated with hypereosinophilic syndrome. Effects of in vivo treatment with MoAbs to adhesion molecules on eosinophilic myocarditis were examined using this experimental model. Expressions of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) on endothelial cells of capillaries in myocardium were increased 1 and 2 weeks after infection. Infiltration of very late antigen (VLA)-4+ and/or CD11a+ cells into the cardiac muscles was also observed 1 and 2 weeks after infection. Infiltration of eosinophils into the heart was significantly suppressed by anti-CD18 MoAb and anti-VLA-4 MoAb, and focal fibrosis of the cardiac muscle was also significantly suppressed by combined administration of anti-CD18 and anti-ICAM-1 MoAbs. These results indicate that adhesion molecules may play important roles in eosinophilic myocarditis, and that blockade of interaction between adhesion molecules and their ligands may help to control it. 相似文献
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BACKGROUND: The purpose of this study was to analyse which lifestyle parameters (daily physical activity, dietary intake, smoking habits and alcohol consumption) discriminate between participants at high-risk and those at low-risk for coronary heart disease (CHD) [systolic and diastolic blood pressure (SBP/DBP), total serum cholesterol (TC), high-density lipoprotein cholesterol (HDL), the TC: HDL ratio, body fatness (sum of skinfolds [SSF]) and cardiopulmonary fitness (VO2-max)]. METHODS: The data were derived from the Amsterdam Growth and Health Study (AGHS); an observational longitudinal study in which six repeated measurements were carried out over a period of 15 years on 181 participants aged 13 years at entry to the study. To assess possible discriminating factors, generalized estimating equations were used. This method makes use of risk group changing behaviour over time by using all available longitudinal data. RESULTS: For DBP no significant relationships were found; high risk for SBP was inversely related to smoking habits (OR=0.52; P<0.01). No significant relationships were found for TC; high risk for HDL was positively related to the intake of carbohydrates (OR=1.2; P=0.02) and to smoking habits (OR=1.6; P=0.04); high risk for the TC:HDL ratio was positively related to the intake of carbohydrates (OR=1.3; P=0.01). High risk for SSF was positively related to the intake of protein (OR=1.5; P<0.01) and smoking habits (OR=1.8; P=0.01) and inversely related to daily physical activity (OR=0.81; P=0.01). High risk for VO2-max was inversely related to daily physical activity (OR=0.67; P<0.01). CONCLUSIONS: In the relative young and healthy population of the AGHS during adolescence and young adulthood, physical inactivity was the most important lifestyle parameter related to high risk for CHD. 相似文献
80.
A case of a mature posterior cervical teratoma resembling two fingers and a case of a lumbosacral limb are presented. These are at least the seventh and eighth reported paraspinous or occipital teratomas with recognizable extremity development. Both anomalies had intradural extension and required exploration to decrease the likelihood of future spinal cord tethering. Preoperative evaluation, surgical technique, postoperative follow-up, and review of the literature are presented. 相似文献