2,004 research outputs found

    Seismic Improvement of RC Beam-Column Joints Using Hexagonal CFRP Bars combined with CFRP Sheets

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    Under severe earthquake conditions, the lack of strength and ductility in reinforced concrete beam–column joints with non-seismic details raises serious concerns for overall structural safety. In this study, experimental research was carried out in order to try and improve the seismic strength and performance of reinforced concrete exterior beam–column joints by applying embedded carbon fiber-reinforced polymer (CFRP) bars combined with CFRP sheets. CFRP bars have a flat-typed hexagonal cross-section. Specimens of reinforced concrete exterior beam–column joints were manufactured based on a newly developed strengthening method by applying embedded CFRP hexagonal bars combined with externally bonded CFRP sheets, and tested for comparison with the specimen of a conventional reinforced concrete exterior beam–column joint. The newly developed design approach could minimize damage and improve the overall structural performances of beam–column joints under cyclic load reversals

    Polymorphism of a COLIA1 Gene Sp1 Binding Site in Korean Women with Pelvic Organ Prolapse

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    PURPOSE: To evaluate the possible influence of G-->T substitution at the Sp1-binding site of the COLIA1 gene on the risk of pelvic organ prolapse (POP). MATERIALS AND METHODS: The study group consisted of 15 women with advanced stage POP. Fifteen control subjects with uterine myomas among the postmenopausal women were matched for age and parity. DNA was obtained from peripheral blood leukocytes. The fragments of the first intron of the COLIA1 gene were amplified by real time polymerase chain reaction. The polymorphism was identified using LightCycler Technology with hybridization probes. Sequencing reactions were performed on each template using commercial primer. RESULTS: Two groups had no significant difference in medical history, surgical, and smoking history. The homozygous peaks in two groups were noted at 57 on melting curve analysis. Sequencing reactions confirmed the G/G alleles in the 30 specimens tested. We could not find any polymorphism at the Sp1-binding site in COLIA1 gene with advanced stage POP. Statistical significance was considered to be p < .05. CONCLUSION: The polymorphism of the Sp1-binding site in the COLIA1 gene did not contribute to the development of POP in Korea.ope

    Acute Symptoms after a Community Hydrogen Fluoride Spill

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    OBJECTIVES: This study was conducted to describe the demographic characteristics, and clinical signs and symptoms of patients who visited a general hospital because of the release of chemically hazardous hydrogen fluoride that occurred on September 27, 2012 in Gumi City, Korea. METHODS: The medical records at 1 general hospital 9 km from the accident site were reviewed using a standardized survey format. There were 1,890 non-hospitalized and 12 hospitalized patients exposed to hydrogen fluoride between September 27 and October 13 2012. RESULTS: Among the 12 hospitalized patients, 11 were discharged within 1 week and the other was hospitalized for 10 days. The chief complaints were respiratory symptoms such as hemoptysis and shortness of breath, gastrointestinal symptoms, neurologic symptoms, sore throat, and lip burn. The number of non-hospitalized patients exhibited a bimodal distribution, peaking on the first and twelfth days after the accident. Their chief complaints were sore throat (24.1%), headache (19.1%), cough (13.1%), and eye irritation (9.2%); some patients were asymptomatic (6.2%). Patients who visited the hospital within 3 days (early patients) of the spill more often had shortness of breath (27.0%) and nausea (6.3%) as the chief complaints than patients who visited after 3 days (late patients) (3.5% and 2.6%, respectively). However, cough and rhinorrhea were more common in the late patients (14.0% and 3.3%, respectively) than in the early patients (5.0% and 0.0%, respectively). Patients who were closer to the accident site more often had shortness of breath and sputum as the chief complaints than patients who were farther away. The mean serum calcium concentration was 9.37 mg/dL (range: 8.4–11.0 mg/dL); none of the patients had a decreased serum calcium level. Among 48 pulmonary function test results, 4 showed decreased lung function. None of the patients had abnormal urine fluoride levels on the eighth day after exposure. CONCLUSIONS: Patients hospitalized due to chemical hazard release of hydrogen fluoride had acute respiratory, gastrointestinal, and neurologic health problems. Non-hospitalized patients have acute symptoms mainly related to upper respiratory irritation

    Occupational Factors Associated with Changes in the Body Mass Index of Korean Male Manual Workers

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    OBJECTIVES: This study was carried out to analyze and compare the occupational factors that could influence changes in body mass index (BMI) in male manual workers stratified into short-term and long-term work experience groups. METHODS: The subjects were 299 male manual workers (sampled systematically) from 27 workplaces, who had undergone travelling medical examinations at a university hospital between March 28 and May 10, 2013, and had also undergone medical examinations at the same hospital in 2012. Their general and occupational characteristics were investigated through a structured, self-administered questionnaire. The BMI at each point in time was calculated based on the anthropometric results of the medical examinations. Multiple regression analyses were conducted on outcomes of the BMI change and predictors composed of the general and occupational characteristics, with the subjects stratified into groups with 5 years or less (short-term) versus more than 5 years (long-term) of work experience at the present post. RESULTS: In the short-term work experience group, the BMI increases of 3-shift workers and groups reporting disagreement with feeling “insufficient job control” and “lack of reward” at work, two of the subscales of job stress, were significantly higher than those of daytime workers and high-stress groups, respectively. In the long-term work experience group, However, although the BMI increase for 3-shift workers was also significantly higher than that of daytime workers, none of the job stress factors were significantly associated with a BMI increase, whereas the social factors of education and marital status were significant, and some lifestyle factors (such as smoking and regular exercise) were also significant. CONCLUSION: This study showed that, except for 3-shift work, the factors associated with BMI increase could differ depending on the length of job experience. Consequently, different strategies may be needed for workers with short-term versus long-term job experience when designing interventions for preventing their obesity

    Adsorptive removal of CO2 from CO2-CH4 mixture using cation-exchanged zeolites

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    Raw natural gas and landfill gas contains methane as its major component, but it also contains considerable amounts of contaminants such as CO2 and H2S (i.e. acid gases) that can cause corrosion and fouling of the pipeline and equipment during transportation and liquefaction. Amine-based CO2 gas removal processes have been employed in the gas industry, but these processes have disadvantages including high regeneration energy requirements and inefficiencies; these issues have not been adequately solved to date. Currently, adsorptive acid gas removal technologies have received significant interest because of the simplicity of adsorbent regeneration by thermal or pressure variation1). Numerous micro- and mesoporous adsorbents including zeolites [2-3], titanosilicates[4], activated carbons[5-6], metal-organic-framework (MOF) [7], and silica-alumina materials[8-9] were studied for this type of application. However, the CO2/CH4 selectivity of the aforementioned adsorbents was not high enough for commercial applications.In this study, different cation-exchanged zeolites were synthesized, physicochemically characterized, and evaluated for adsorptive removal of CO2 from CO2-CH4 mixtures. The adsorption isotherms of CO2 and CH4 in the pressure and temperature ranges 0 − 3MPa and 10 – 40 oC, respectively, for different cation-exchanged zeolites were measured and compared. The ideal-adsorbed solution theory (IAST) was employed for the estimation of CO2/CH4 selectivity for the different cation-exchanged zeolites. References 1) D. Aaron, C. Tsouris, Separ. Sci. Technol. 2005, 40, 321–348 2) J. Collins, US Patent No. 3,751,878. 1973. 3) M. W. Seery, US Patent No. 5,938,819. 1999 4) W. B. Dolan, M.J. Mitariten, US Patent No. 6,610,124 B1. 2003 5) A. Kapoor, R.T. Yang, Chem. Eng. Sci. 1989, 44, 1723–1733 6) A. Jayaraman, Chiao, A. S.; Padin, J.; Yang, R. T.; Munson, C. L., Separ. Sci. Technol. 2002 37, 2505–2528 7) L. Hamon, E. Jolimaitre, G. Pringruber , Ind. Eng. Chem. Res. 2010, 49, 7497-7503 8) W.B. Dolan, M.J. Mitariten, US patent No. 2003/0047071, 2003 9) G. Bellussi, P. Broccia, A. Carati, R. Millini, P. Pollesel, C. Rizzo, M. Tagliabue, Micropor. Mesopor. Mat., 2011, 146, 134–14
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