Browsing by Author "Lin, Fang"

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    Epidemiological characteristics and burden of childhood and adolescent injuries: a survey of elementary and secondary students in Xiamen, China
    Fang, Ya; Zhang, Xiang; Chen, Wei; Lin, Fang; Yuan, Manqiong; Geng, Zhi; Yu, Hong; Dai, Long (2015-04-10)
    Background Injuries pose a considerable threat to the health of children and adolescents, and childhood injuries cause substantial economic loss for families and society. Many injuries are preventable. To provide a theoretical basis and empirical support for injury prevention interventions, we studied the epidemiological characteristics, risk factors, and burden of injuries among elementary and secondary school students in Xiamen, China. Methods Participants were enrolled through multi-stage stratified cluster random sampling of elementary and secondary students in Xiamen in 2010. Questionnaires were completed by students’ parents or guardians to assay students’ basic information, family background, occurrence of injuries in the past year, and burden of injuries. Chi-square tests and logistic regression were performed to identify the key factors of injuries. Results A total of 2,816 usable questionnaires reported 365 injury incidents in 303 students over 1 year. The incidence of injuries was 10.8%. Students who were male, extroverted, suburban, had sibling(s), studied in grades 4–9, or whose parents were divorced or separated were more likely to suffer from injuries. Most injuries occurred during the summer months (from June to August), and in the afternoon. The main affected body parts were limbs, fingers or toes. Unintentional falls, collisions/strikes, sprains, and cuts/sharp instrument injuries were the predominant causes of injury. The overall economic burden of the 365 injury incidents was 1,014,649.1 RMB (148,666.5 USD) total, 3,348.7 RMB (490.65 USD) per capita, and 2,779.9 RMB (407.31 USD) per incident. Conclusion The injury incidence among elementary and secondary students in Xiamen, China is lower than Guangdong and Zhejiang but higher than Beijing and Shanghai. Injuries caused substantial economic and family burdens and threatened students’ health and life. Childhood and adolescent injuries have become a serious public health problem that requires the urgent attention of the government, society, schools, and families. Injury control and prevention among elementary and secondary school students is essential and will help in multiple ways to reduce the burden on the family to build a harmonious family and society.
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    Experimental Study of the PVTX Properties of the System H₂O-CH₄
    Lin, Fang (Virginia Tech, 2005-09-23)
    The system H₂O-CH₄ is found in a variety of geological environments in the earth’s crust, from sedimentary basins to low grade metamorphic terrains. Knowledge of the PressureVolume-Temperature-Composition (PVTX) properties of the H₂O-CH₄ system is necessary to understand the role that these fluids play in different geological environments. In this study the properties of the H₂O-CH₄ fluid system at elevated temperatures and pressures has been investigated experimentally to determine the PVTX properties of H₂O-CH₄ fluids in the P-T range equivalent to late diagenetic to low grade metamorphic environments, and XCH₄≤4mol%. A study has also been conducted to determine methane hydrate stability over the temperature range of -40~20°C. Synthetic fluid inclusions were employed in both studies as miniature autoclaves. Experimental data for the PVTX properties of H₂O-CH₄ fluids under late diagenetic to low grade metamorphic conditions was used to calculate the slopes of isoTh lines (the line connecting the P-T conditions of the inclusions at formation and at homogenization) at different PTX conditions. An empirical equation to describe the slope of iso-Th line as a function of homogenization temperature and fluid composition was developed. The equation is applicable to natural H₂O-CH₄ fluid inclusions up to 500°C and 3 kilobars, for fluid compositions ≤4 mol% CH₄. The Raman peak position of CH₄ gas is a function of the pressure and temperature. This relationship was used to determine the pressure along the methane hydrate stability curve in the H₂O-CH₄ system. The combined synthetic fluid inclusion, microthermometry and Raman spectroscopy method is a novel experimental approach to determine the P-T stability conditions of methane hydrates. The method is fast compared to conventional methods, and has the potential to be applied to study other gas hydrate systems.