• Title/Summary/Keyword: hazard levels

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Field Measurement of Water Discharge by using Surface Image Velocimetry (표면영상유속계(SIV)를 이용한 현장유량측정)

  • Kim, Seo-Joon;Joo, Yong-Woo;Yu, Kwon-Kyu;Yoon, Byung-Man
    • 한국방재학회:학술대회논문집
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    • 2008.02a
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    • pp.739-742
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    • 2008
  • Surface Image Velocity (SIV) is a technique which measures the surface velocity of river by using the principle of Paticle Image Velocimetry (PIV). The technique is economical and efficient way to measure velocity in rivers. The present paper aims to apply the technique to three rivers in Korea. It uses pairs of river surface images taken with two digital-cameras and reference points and cross section data which were acquired through plane survey. The performance of SIV was verified with automatic cart on an experimental flume. The test revealed that average error was less than 10 %, which assures that SIV can be used to measure velocity accurately. When it was applied to rivers with low water levels or rough weather condition, however, it showed the error about 20 %. If the problems of SIV technique are settled down, it can be one of the most convenient and economical ways to measure water discharge anytime and anywhere. And then it would be helpful to river management as developing a real-time river information system.

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Seismic Fragility Analysis for Probabilistic Seismic Performance Evaluation of Multi-Degree-of-Freedom Bridge Structures (확률론적 내진성능평가를 위한 다자유도 교량구조물의 지진취약도해석)

  • Jin, He-Shou;Song, Jong-Keol
    • 한국방재학회:학술대회논문집
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    • 2008.02a
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    • pp.269-272
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    • 2008
  • The seismic fragility curves of a structure represents the probability of exceeding the prescribed structural damage given various levels of ground motion intensityand the seismic fragility curve is essential to evaluation of structural performance and assessment of risk and loss of structures. The purpose of this paper is to develop seismic fragility functions for bridge structures in Koreaby reviewing those of advanced countries. Therefore, at first, we investigated development conditions of the seismic fragility functions. And the next highway bridges in Korea are classified into a number of categories and several typical bridges are selected to estimate seismic fragilities for using this analysis method in Korea. Finally, fragility curves for PSC Box girder bridge are estimated. The results show that the bridge classification and damage state play an important role in estimation of seismic damage and seismic fragility analysis for bridge structures.

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Chemical Risk Assessment Screening Tool of a Global Chemical Company

  • Tjoe-Nij, Evelyn;Rochin, Christophe;Berne, Nathalie;Sassi, Alessandro;Leplay, Antoine
    • Safety and Health at Work
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    • v.9 no.1
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    • pp.84-94
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    • 2018
  • Background: This paper describes a simple-to-use and reliable screening tool called Critical Task Exposure Screening (CTES), developed by a chemical company. The tool assesses if the exposure to a chemical for a task is likely to be within acceptable levels. Methods: CTES is a Microsoft Excel tool, where the inhalation risk score is calculated by relating the exposure estimate to the corresponding occupational exposure limit (OEL) or occupational exposure band (OEB). The inhalation exposure is estimated for tasks by preassigned ART1.5 activity classes and modifying factors. Results: CTES requires few inputs. The toxicological data, including OELs, OEBs, and vapor pressure are read from a database. Once the substance is selected, the user specifies its concentration and then chooses the task description and its duration. CTES has three outputs that may trigger follow-up: (1) inhalation risk score; (2) identification of the skin hazard with the skin warnings for local and systemic adverse effects; and (3) status for carcinogenic, mutagenic, or reprotoxic effects. Conclusion: The tool provides an effective way to rapidly screen low-concern tasks, and quickly identifies certain tasks involving substances that will need further review with, nevertheless, the appropriate conservatism. This tool shows that the higher-tier ART1.5 inhalation exposure assessment model can be included effectively in a screening tool. After 2 years of worldwide extensive use within the company, CTES is well perceived by the users, including the shop floor management, and it fulfills its target of screening tool.

RADIOLOGICAL CHARACTERISTICS OF DECOMMISSIONING WASTE FROM A CANDU REACTOR

  • Cho, Dong-Keun;Choi, Heui-Joo;Ahmed, Rizwan;Heo, Gyun-Young
    • Nuclear Engineering and Technology
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    • v.43 no.6
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    • pp.583-592
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    • 2011
  • The radiological characteristics for waste classification were assessed for neutron-activated decommissioning wastes from a CANDU reactor. The MCNP/ORIGEN2 code system was used for the source term analysis. The neutron flux and activation cross-section library for each structural component generated by MCNP simulation were used in the radionuclide buildup calculation in ORIGEN2. The specific activities of the relevant radionuclides in the activated metal waste were compared with the specified limits of the specific activities listed in the Korean standard and 10 CFR 61. The time-average full-core model of Wolsong Unit 1 was used as the neutron source for activation of in-core and ex-core structural components. The approximated levels of the neutron flux and cross-section, irradiated fuel composition, and a geometry simplification revealing good reliability in a previous study were used in the source term calculation as well. The results revealed the radioactivity, decay heat, hazard index, mass, and solid volume for the activated decommissioning waste to be $1.04{\times}10^{16}$ Bq, $2.09{\times}10^3$ W, $5.31{\times}10^{14}\;m^3$-water, $4.69{\times}10^5$ kg, and $7.38{\times}10^1\;m^3$, respectively. According to both Korean and US standards, the activated waste of the pressure tubes, calandria tubes, reactivity devices, and reactivity device supporters was greater than Class C, which should be disposed of in a deep geological disposal repository, whereas the side structural components were classified as low- and intermediate-level waste, which can be disposed of in a land disposal repository. Finally, this study confirmed that, regardless of the cooling time of the waste, 15% of the decommissioning waste cannot be disposed of in a land disposal repository. It is expected that the source terms and waste classification evaluated through this study can be widely used to establish a decommissioning/disposal strategy and fuel cycle analysis for CANDU reactors.

The Development of the HACCP Plan in Korean Rice Cake Manufacturing Facilities (시판 떡류 생산에서 HACCP Plan 개발을 위한 연구)

  • Lee, Hyo-Soon;Jang, Myung-Sook
    • Korean journal of food and cookery science
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    • v.24 no.5
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    • pp.652-664
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    • 2008
  • In this study, a Hazard Analysis Critical Control Point (HACCP) plan was developed for the sanitary mass production of commercial Korean rice cake products (Gaepidduk, Injulmi, and Julpyon). The microbiological properties of manufacturing flow were evaluated in order to develop the HACCP Plan. The moisture contents of the rice cakes ranged between 36.2${\sim}$55.3%, whereas the water activity of all samples ranged between 0.954${\sim}$1.0. Microorganisms testing was conducted during various phases of the product flow of Korean rice cake preparation, and included assessments of food equipment, work environment, and cooking employees on a small scale. During the manufacture of Injulmi, Julpyon and Gaepidduk, CCPs were purchasing & storage, steaming and cooling, molding, and holding in the A and B manufactories. At the critical limit of CCPs, storage was conducted below at $5^{\circ}C$ in soybean powder, oil, and paste with redbeans. The steaming process was conducted above at $99^{\circ}C$ for 40 min. Cooling and holding processes were conducted for 2 hours below at $15^{\circ}C$. The molding process included sanitary education for foodhandlers and training for operators. Thus, certain prerequisite programs had to be implemented prior to the implementation of the HACCP system. High levels of bacterial contamination were detected in the aprons worn to work by some employees. Additionally, periodic sanitary education for foodhandlers and training for operators or managers was required. Cross contamination by materials was expected at the place where materials were processed or stored.

A Comprehensive review of raisins and raisin components and their relationship to human health

  • Schuster, Margaret J.;Wang, Xinyue;Hawkins, Tiffany;Painter, James E.
    • Journal of Nutrition and Health
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    • v.50 no.3
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    • pp.203-216
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    • 2017
  • Purpose: This literature review was performed to assess the effect of raisins on human health. Methods: A review of Medline was conducted using the keywords: 'raisins, raisins and health, raisins and cardiovascular disease (CVD), raisins and cancer, raisins and diabetes, raisins and fiber, raisins and colon health, raisins and antioxidants, raisins and inflammation, raisins and dental caries'. The reference lists from previous review articles on raisins and human health and the California Raisin Marketing Board files were reviewed for additional studies. Results: Raisins have one of the highest polyphenolic content and antioxidant ORAC levels compared to other traditional dried fruits. Many of the polyphenols in raisins are well assimilated and bioavailable. Raisin consumption reduces low density lipoprotein (LDL) cholesterol, blood pressure and blood sugar, when compared to equal caloric carbohydrate snacks and is associated with a reduced risk of CVD. The anti-inflammatory and cancer chemopreventive effects of raisins are mixed. Raisin consumption reduces intestinal transit time and positively affects gut microbiota. Raisins produce sustained energy during long term athletic competitions equal to traditional sports energy gels, shots and jelly beans. Raisins produce a non-cariogenic oral environment and do not fit the American Academy of Pediatrics criteria to be considered a choking hazard. Conclusions: Based on the review of literature, consumption of raisins provide numerous health benefits for promoting general wellness and in the prevention of many chronic diseases including: CVD, type 2 diabetes mellitus (T2DM) gastrointestinal diseases, and dental caries.

Women's Wage and Childbearing (여성임금과 출산력)

  • Choi, Seul-Ki
    • Korea journal of population studies
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    • v.35 no.2
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    • pp.29-53
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    • 2012
  • This research studies how women's hourly wages affect childbearing using data from the National Longitudinal Survey of Youth. The results of discrete time hazard model show that the relationship between women's hourly wage and fertility is dynamic. Overall relationship looks negative, but they are not consistent across education levels. Women who have a high school diploma or less have a tendency to decrease childbearing when their wages increase. But women who have some college experience or a college degree are likely to have children when their wages increase. It means that only for highly educated women who are likely to be in high paying decent jobs, the rise of income can be used as a resource for reconciling the mother's and worker's roles. Or, for less educated women who are likely to be in the low paying jobs, the rise of income is not large enough to lessen role incompatibility.

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Risk Factors for Displacement of the Abomasum in Dairy Cows and its Relationship with Postpartum Disorders, Milk Yield, and Reproductive Performance

  • Kang, Hyun-Gu;Jeong, Jae-Kwan;Kim, Ill-Hwa
    • Journal of Veterinary Clinics
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    • v.36 no.1
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    • pp.68-73
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    • 2019
  • We determined the risk factors for displacement of the abomasum (DA), and the relationships between DA and postpartum disorders, milk yield, and reproductive performance in dairy cows. Initially, we identified the risk factors for DA using data regarding cow health and calving season from 2,208 lactations. Then, we compared the incidence of postpartum disorders, culling, death, and reproductive performance between cows with DA and their control herdmates (each n = 57). In addition, serum metabolites concentrations and milk yield were compared between cows with DA and controls (each n = 33). Ketosis (odds ratio [OR] = 9.27, p < 0.0001) and twin calves (p = 0.06) increased the risk of DA. Cows with a parity of three had a higher risk (OR = 5.23, p < 0.01) of DA than primiparous cows. Serum total cholesterol concentration was lower but non-esterified fatty acid, ${\beta}-hydroxybutyrate$, and alanine aminotransferase concentrations were higher after calving in cows with DA than in controls (p < 0.05). The removal rate from the herd by 2 months after calving was higher (p < 0.05) but milk yield 1 and 2 months after calving (p < 0.01) and the rate of first insemination by 150 days postpartum were lower (hazard ratio = 0.49, p < 0.05) in cows with DA than controls. In conclusion, higher parity, twin calves, and ketosis are risk factors for DA in dairy cows, which is associated with a higher removal rate from the herd, lower milk yield, a longer calving to first insemination interval, and unfavorable levels of metabolites related to energy and liver function.

Nonalcoholic fatty liver disease in obese and nonobese pediatric patients

  • Kim, Eun Jeong;Kim, Hyun Jin
    • Clinical and Experimental Pediatrics
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    • v.62 no.1
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    • pp.30-35
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    • 2019
  • Purpose: Obesity is risk factor for nonalcoholic fatty liver disease (NAFLD). However, nonobese patients are also increasingly susceptible to NAFLD. The aim of this study was to compare the clinical characteristics of obese and nonobese pediatric patients with NAFLD. Methods: We retrospectively studied 68 patients who were diagnosed with NAFLD between January 2010 and October 2016 at 10-18 years of age. Body mass index ${\geq}95th$ percentile for age and sex was defined as obesity. Abdominal ultrasonography and laboratory, anthropometrics measurements were evaluated. Results: Among the 68, 26 (38.2%) were nonobese patients. The ratio of male to female was 5.8:1, and the median age at diagnosis was 13 years (range, 10-17 years). Significant higher triglyceride (223.0 mg/dL vs. 145.9 mg/dL, P=0.047) and total cholesterol levels (211.6 mg/dL vs. 173.2 mg/dL, P=0.011) were shown in nonobese than obese patients. High-density lipoprotein cholesterol level <40 mg/dL (hazard ratio [HR], 6.5; 95% confidence interval [CI], 2.13-7.10; P=0.048), total cholesterol level >200 mg/dL (HR, 5.6; 95% CI, 1.23-15.31; P=0.038) and abdominal obesity (HR, 2.53; 95% CI, 1.22-4.68; P=0.013) were significant risk factors for NAFLD in nonobese patients. Conclusion: Nonobese patients present a substantial proportion of pediatric NAFLD cases. Significant abnormal lipid concentrations were found in nonobese and abdominal obesity was important risk factor for nonobese NAFLD.

Impact of Insulin Resistance on Acetylcholine-Induced Coronary Artery Spasm in Non-Diabetic Patients

  • Kang, Kwan Woo;Choi, Byoung Geol;Rha, Seung-Woon
    • Yonsei Medical Journal
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    • v.59 no.9
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    • pp.1057-1063
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    • 2018
  • Purpose: Coronary artery spasm (CAS) and diabetes mellitus (DM) are implicated in endothelial dysfunction, and insulin resistance (IR) is a major etiological cause of type 2 DM. However, the association between CAS and IR in non-diabetic individuals has not been elucidated. The aim of the present study was to evaluate the impact of IR on CAS in patients without DM. Materials and Methods: A total of 330 eligible patients without DM and coronary artery disease who underwent acetylcholine (Ach) provocation test were enrolled in this study. Inclusion criteria included both hemoglobin A1c <6.0% and fasting glucose level <110 mg/dL without type 2 DM. Patients were divided into quartile groups according the level of homeostasis model assessment of insulin resistance (HOMA-IR): 1Q (n=82; HOMA-IR<1.35), 2Q (n=82; $1.35{\leq}HOMA-IR<1.93$), 3Q (n=83; $1.93{\leq}HOMA-IR<2.73$), and 4Q (n=83; $HOMA-IR{\geq}2.73$). Results: In the present study, the higher HOMA-IR group (3Q and 4Q) was older and had higher body mass index, fasting blood glucose, serum insulin, hemoglobin A1c, total cholesterol, and triglyceride levels than the lower HOMA-IR group (1Q). Also, poor IR (3Q and 4Q) was considerably associated with frequent CAS. Compared with Q1, the hazard ratios for Q3 and Q4 were 3.55 (95% CI: 1.79-7.03, p<0.001) and 2.12 (95% CI: 1.07-4.21, p=0.031), respectively, after adjustment of baseline risk confounders. Also, diffuse spasm and accompanying chest pain during Ach test were more strongly associated with IR patients with CAS. Conclusion: HOMA-IR was significantly negatively correlated with reference diameter measured after nitroglycerin and significantly positively correlated with diffuse spasm and chest pain.