• 제목/요약/키워드: hazard levels

검색결과 446건 처리시간 0.025초

Safety Levels Apportionment in Railway System

  • Rafrafi, Meriem;El Koursi, El Miloudi;Bourdeaud'Huy, Thomas
    • International Journal of Railway
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    • 제1권4호
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    • pp.157-168
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    • 2008
  • The creation of a single European rail transport market it is important to increase confidence between the actors on the market and between member states who shall ensure that railway safety is generally maintained and, where reasonably practicable, continuously improved. For this purpose the European railway safety directive introduces a mechanism to adopt a Common Safety Targets (CST) expressed in risk acceptance criteria for individuals and for society. This paper focuses on the apportionment of safety targets for European railway system. We develop a generic approach based on the Functional Hazard Analysis (FHA), to analyse the safety of railway systems for a unified European network and to comply with the CSTs required by the European railway Safety Directive. We suggest to combine the FHA technique with the functional railway architecture to allocate the safety targets to the railway functions.

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Estimation of structural dynamic characteristics of the Egyptian Obelisk of Theodosius

  • Saygili, Ozden
    • Earthquakes and Structures
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    • 제16권3호
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    • pp.311-320
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    • 2019
  • Obelisks are historical monuments. There are several obelisks dating from ancient Egyptian period, located around various parts of the world. The city of Istanbul is a home to the Obelisk of Theodosius at the Hippodrome. Due to the expectation of a large event in the near future, the evaluation of seismic response of the Obelisk gets importance. Therefore, in this study structural dynamic behavior of the Obelisk was investigated using discrete element approach. Nonlinear dynamic analyses were performed using real and synthetic time series. Real and synthetic ground motions analyzed from this study seems consistent with the earthquake hazard levels that would be expected at the site of the Obelisk in the occurrence of an event of moment magnitude above 7.0 near Istanbul. Results are evaluated in terms of variation of displacement, relative displacement of adjacent blocks, normal stress and shear stress in time.

국내 폐금속 광산지역에서의 토양, 지하수, 쌀의 중금속 노출에 따른 인체 위해성평가 (Risk Assessment for Heavy Metals in Soil, Ground Water, Rice Grain nearby Abandoned Mine Areas)

  • 나은식;이용재;고광용;정덕영;이규승
    • 한국환경농학회지
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    • 제32권4호
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    • pp.245-251
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    • 2013
  • BACKGROUND: The objectives of this study are to investigate the contamination levels of heavy metals in soil, ground water, and agricultural product near the abandoned Boeun and Sanggok mine areas in Korea and to assess the health risk for these local residents exposed to the toxic heavy metals based on analytical data. METHODS AND RESULTS: By the results of human health risk assessment for local residents around Boeun and Sanggok, human exposure to cadmium, copper, arsenic from soil and to lead, cadmium, and arsenic from rice grain were higher in Sanggok, but human exposure to zinc and arsenic from ground water was higher in Boeun. By the results of hazard index (HI) evaluation for arsenic, cadmium, copper, lead, and zinc, HI values in both areas were higher than 1.0. This result indicated that the toxicity hazard through the continuous exposure to lead, cadmium, arsenic from rice, ground water, and soil would be likely to occur to the residents in the areas. Cancer risk assessment for arsenic, risks from the rice were exposed to one to two out of 10,000 people in Boeun and one of 1,000 people in Sanggok. These results showed that the cancer risks of arsenic in both areas were 10~100 times greater than the acceptable cancer risk range of US EPA ($1{\times}10^{-6}{\sim}1{\times}10^{-5}$). CONCLUSION(S): Therefore, if these two local residents consume continuously with arsenic contaminated soil, ground water, and rice, the adverse health effects (carcinogenic potential) would be more increased.

Hazards Caused by UV Rays of Xenon Light Based High Performance Solar Simulators

  • Dibowski, Gerd;Esser, Kai
    • Safety and Health at Work
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    • 제8권3호
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    • pp.237-245
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    • 2017
  • Background: Solar furnaces are used worldwide to conduct experiments to demonstrate the feasibility of solar-chemical processes with the aid of concentrated sunlight, or to qualify high temperature-resistant components. In recent years, high-flux solar simulators (HFSSs) based on short-arc xenon lamps are more frequently used. The emitted spectrum is very similar to natural sunlight but with dangerous portions of ultraviolet light as well. Due to special benefits of solar simulators the increase of construction activity for HFSS can be observed worldwide. Hence, it is quite important to protect employees against serious injuries caused by ultraviolet radiation (UVR) in a range of 100 nm to 400 nm. Methods: The UV measurements were made at the German Aerospace Center (DLR), Cologne and Paul-Scherrer-Institute (PSI), Switzerland, during normal operations of the HFSS, with a high-precision UV-A/B radiometer using different experiment setups at different power levels. Thus, the measurement results represent UV emissions which are typical when operating a HFSS. Therefore, the biological effects on people exposed to UVR was investigated systematically to identify the existing hazard potential. Results: It should be noted that the permissible workplace exposure limits for UV emissions significantly exceeded after a few seconds. One critical value was strongly exceeded by a factor of 770. Conclusion: The prevention of emissions must first and foremost be carried out by structural measures. Furthermore, unambiguous protocols have to be defined and compliance must be monitored. For short-term activities in the hazard area, measures for the protection of eyes and skin must be taken.

전자기파의 생체 위해성에 관한 소고 (Biological Hazard of Electromagnetic Field Exposure: A Review)

  • 정경아;계명찬
    • 환경생물
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    • 제29권4호
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    • pp.241-250
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    • 2011
  • 현대인들은 가정생활과 직업환경 속에서 다양한 종류의 전자기파에 노출되며 전자기파 노출에 따른 생체위해성은 공중보건학적으로 중요한 이슈로 대두되었다. 현재까지 많은 체외 및 체내실험 결과에서 전자기파 노출이 세포대사, 내분비, 면역, 신경, 생식, 태아발달에 영향을 미치는 것으로 보고되었다. 세포나 개체 수준에서 시행된 실험연구에서는 전자기파 노출에 의해 세포내부 자유기의 증가, DNA 손상과 암발생, 발생기형, 생식기능 저하가 나타난다. 역학조사결과 전자기파 노출은 생명을 위협하는 질병인 백혈병, 뇌암, 근위축성 측삭경화증, 우울증, 자살, 알츠하이머와 상관성이 보고되었다. 이러한 생체기능 변화는 전자기파의 주파수, 노출기간, 강도 (에너지)에 따라 다르게 나타난다. 전자기파 노출은 곤충, 어류, 양서류, 파충류, 조류 등 야생동물에서도 동물행동, 번식, 생리기능의 변화를 초래한다. 본 소고에서는 인간보건학적 측면과 생태계에서 나타난 전자기파의 위해성을 전자기파의 종류, 노출시간에 따라 세포 및 개체 수준에서 보고된 위해성 자료를 정리하였다.

공간 예측 모델을 이용한 산사태 재해의 인명 위험평가 (Life Risk Assessment of Landslide Disaster Using Spatial Prediction Model)

  • 장동호
    • 환경영향평가
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    • 제15권6호
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    • pp.373-383
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    • 2006
  • The spatial mapping of risk is very useful data in planning for disaster preparedness. This research presents a methodology for making the landslide life risk map in the Boeun area which had considerable landslide damage following heavy rain in August, 1998. We have developed a three-stage procedure in spatial data analysis not only to estimate the probability of the occurrence of the natural hazardous events but also to evaluate the uncertainty of the estimators of that probability. The three-stage procedure consists of: (i)construction of a hazard prediction map of "future" hazardous events; (ii) validation of prediction results and estimation of the probability of occurrence for each predicted hazard level; and (iii) generation of risk maps with the introduction of human life factors representing assumed or established vulnerability levels by combining the prediction map in the first stage and the estimated probabilities in the second stage with human life data. The significance of the landslide susceptibility map was evaluated by computing a prediction rate curve. It is used that the Bayesian prediction model and the case study results (the landslide susceptibility map and prediction rate curve) can be prepared for prevention of future landslide life risk map. Data from the Bayesian model-based landslide susceptibility map and prediction ratio curves were used together with human rife data to draft future landslide life risk maps. Results reveal that individual pixels had low risks, but the total risk death toll was estimated at 3.14 people. In particular, the dangerous areas involving an estimated 1/100 people were shown to have the highest risk among all research-target areas. Three people were killed in this area when landslides occurred in 1998. Thus, this risk map can deliver factual damage situation prediction to policy decision-makers, and subsequently can be used as useful data in preventing disasters. In particular, drafting of maps on landslide risk in various steps will enable one to forecast the occurrence of disasters.

사면구조 격자 기법에 의한 2차원 홍수범람모형의 적용 (Application of a Two-dimensional Flood Inundation Model based on Quadtree Grid)

  • 김종호;이승오;윤광석;조용식
    • 한국방재학회 논문집
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    • 제8권3호
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    • pp.129-136
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    • 2008
  • 홍수 예방을 위해 사용되는 구조적 또는 비구조적 대책의 성공여부는 홍수 예측의 정확도에 달려있다. 본 연구에서는 홍수 범람 발생유무, 범람 면적 또는 최대수위를 예측 및 모의가 가능한 수치모형을 개발하였다. 비선형 Saint-Venant 방정식을지 배방정식으로 사용하였으며, 적합화된 계층적 사면구조 격자를 적용하여, leap-frog 기법과 upwind 기법으로 양해적으로 유한차분하였다. 개발된 수치 모형은 Thacker 문제의 결과와 비교하여 검증하였고, 경상남도 의령 지역에 사면구조 격자를 사용한 본 모형을 적용하였다. 검증 결과 본 모형의 격자는 균일 격자보다 거의 4배 정도 효율적이었으며, 정확도 측면에서도 이전 모델의 결과와 거의 일치함을 알 수 있었다. 다음은 수문 빈도를 변화시키면서 홍수 범람 양상을 수치 모의하였다. 빈도가 증가하면, 첨두 수위를 비롯한 수위 수문곡선의 크기도 증가함을 알 수 있었고, 500년 빈도에서는 제방을 월류하여, 제내지에 범람함을 예측할 수 있었다.

Effect of Comprehensive Breast Care on Breast Cancer Outcomes: A Community Hospital Based Study from Mumbai, India

  • Gadgil, Anita;Roy, Nobhojit;Sankaranarayanan, Rengaswamy;Muwonge, Richard;Sauvaget, Catherine
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권4호
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    • pp.1105-1109
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    • 2012
  • Breast cancer is the second most common cancer in women in India and the disease burden is increasing annually. The lack of awareness initiatives, structured screening, and affordable treatment facilities continue to result in poor survival. We present a breast cancer survival scenario, in urban population in India, where standardised care is distributed equitably and free of charge through an employees' healthcare scheme. We studied 99 patients who were treated at our hospital during the period 2005 to 2010 and our follow-up rates were 95.95%. Patients received evidence-based standardised care in line with the tertiary cancer centre in Mumbai. One-, three- and five-year survival rates were calculated using Kaplan-Meier method. Socio-demographic, reproductive and tumor factors, relevant to survival, were analysed. Mortality hazard ratios (HR) were calculated using Cox proportional hazard method. Survival in this series was compared to that in registries across India and discrepancies were discussed. Patients mean age was 56 years, mean tumor size was 3.2 cms, 85% of the tumors belonged to T1 and T2 stages, and 45% of the patients belonged to the composite stages I and IIA. Overall 5-year survival was 74.9%. Patients who presented with large-sized tumors (HR 3.06; 95% CI 0.4-9.0), higher composite stage (HR 1.91; 0.55-6.58) and undergone mastectomy (HR 2.94; 0.63-13.62) had a higher risk of mortality than women who had higher levels of education (HR 0.25; 0.05-1.16), although none of these results reached the significant statistical level. We observed 25% better survival compared to other Indian populations. Our results are comparable to those from the European Union and North America, owing to early presentation, equitable access to standardised free healthcare and complete follow-up ensured under the scheme. This emphasises that equitable and affordable delivery of standardised healthcare can translate into early presentation and better survival in India.

Prognostic Role of PTEN Gene Expression in Breast Cancer Patients from North-East Iran

  • Golmohammadi, Rahim;Rakhshani, Mohammad Hassan;Moslem, Ali Reza;Pejhan, Akbar
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권9호
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    • pp.4527-4531
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    • 2016
  • Background: PTEN protein is one of the most important tumour suppressor factors which is detectable by immunohistochemistry. The goal of the present study was to investigate the prognostic role of PTEN gene expression in breast cancer patients. Materials and Methods: This descriptive-analytical study was conducted on 100 breast cancer patients referred to Sabzevar hospitals in the north-east of Iran between 2010 and 2011, who were followed up to 2015. PTEN gene expression in tissue samples was determined using specific monoclonal antibodies and data were analyzed using Chi-square test and Fisher's exact test. Patient survival was analyzed after 4 years of follow-up using the Cox regression model. Results: PTEN gene expression was evident in 70 of 100 cnacer samples but was found at high levels in all non-cancer samples. There was an inverse significant relationship between PTEN gene expression and tumour stage or tumour grade (p<0.001). The expression of PTEN in invasive ductal tumours was lower than in non-invasive tumours. There was also an inverse significant relationship between the hazard of death and PTEN gene expression (p<0.001). In addition, there was an inverse significant relationship between tumour stage and hazard of death (p<0.001). Conclusion: These findings indicate that lack of PTEN gene expression can be a sign of a worse prognosis and poor survival in breast cancer cases.

Occupational Exposure to Potentially Infectious Biological Material Among Physicians, Dentists, and Nurses at a University

  • Reis, Leonardo Amaral;La-Rotta, Ehidee Isabel Gomez;Diniz, Priscilla Barbosa;Aoki, Francisco Hideo;Jorge, Jacks
    • Safety and Health at Work
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    • 제10권4호
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    • pp.445-451
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    • 2019
  • Objective: The objective of this study was to evaluate the prevalence and incidence of accidents with biological material, the level of knowledge, and compliance to standard precautions (SPs) among dentists, physicians, nurses, and dental and medical students. Methods: A closed cohort study with a prospective and retrospective component was conducted between August 2014 and September 2015. The participants were contacted in two moments during the follow-up period, during which a structured questionnaire divided into six sections was used; the interviews were conducted during the follow-up period (Month 6) and at the end of the observation period (Month 12). Results: The global prevalence of accidents in the previous 12 months was 10.2%, with a difference between professionals and students (13.0% vs. 5.1%, respectively; p < 0.003). The incidence rate was 6.49 per 100 person/year, with difference between the groups (6.09 per 100 person/year in professionals and 7.26 per 100 person/year in students), type of specialization (hazard ratio, 3.27), and hours worked per week (hazard ratio, 2.27). The mean of compliance to SP was 31.99 (±3.85) points, with a median of 33 (30, 35) points against the expected 27.75 points. Adherence to SP was associated with the accident report (p < 0.020). Conclusion: We conclude that the proportion/incidence rate of accidents with biological material was high in relation to that in the literature, being higher in professionals and especially among physicians. The levels of knowledge and adherence to SP were good, with the best found in dentists and dental students.