• 제목/요약/키워드: Fractional effective dose

검색결과 24건 처리시간 0.028초

교통정체가 심한 도로터널에 대한 화재시 제연방식에 관한 연구 (The study of ventilation system during fire in road tunnel with bi-directional or congested unidirectional traffic)

  • 유지오;신현준;남창호
    • 대한설비공학회:학술대회논문집
    • /
    • 대한설비공학회 2008년도 하계학술발표대회 논문집
    • /
    • pp.474-479
    • /
    • 2008
  • The purpose of this paper is to estimate the fire safety in tunnels with bi-directional and/or congested unidirectional traffic where there may be people on both sides of the fire. Therefore, the spread and movement of smoke are simulated by Fire Dynamic Simulator code under different ventilation systems, longitudinal, semi-transverse, large port exhaust system. And as quantitative risk index, FED (Fractional Effective Dose) for each ventilation system are calculated and compared by existed code developed previous research.

  • PDF

다중 센서들을 이용한 다양한 화재 상황의 위험도 추정 시스템 개발 (Implementation of Fire Risk Estimation System for various Fire Situations using Multiple Sensors)

  • 이광재;이연성
    • 센서학회지
    • /
    • 제25권6호
    • /
    • pp.394-398
    • /
    • 2016
  • In this paper, a fire detection system based on quantitative risk estimation is presented. Multiple sensors are used to build a comprehensive indicator that represents the risk of fire quantitatively. The proposed fire risk estimation method consists of two stages which determines the occurrence of fire and estimates the toxicity of the surveillance area. In the first stage, fire is reliably detected under diverse fire scenarios. The risk of fire is estimated in the second stage. Applying Purser's Fractional Effective Dose (FED) model which quantitates harmfulness of toxic gases, the risk of the surveillance area and evacuation time are calculated. A fire experiment conducted using four different types of combustion materials for the verification of the system resulted in a maximum error rate of 12.5%. By using FED calculation and risk estimation methods, the proposed system can detect various signs of fire faster than conventional systems.

FDS_EVAC에 적용된 독성가스모델(FED)이 피난에 미치는 영향 분석 및 개선에 대한 연구 (Numerical Analysis on the Effect of Improved Fractional Effective Dose(FED) for Evacuation by FDS_EVAC)

  • 김홍진;배승용;최영기;홍기배;유홍선
    • 한국안전학회지
    • /
    • 제28권1호
    • /
    • pp.125-131
    • /
    • 2013
  • When fire occurs in complex or building, toxic gas is important factor for evacuation because it cause death of evacuees. The effect of toxic gas which effects human motion is calculated using Purser's Fractional Effective Dose(FED). The FDS_EVAC is used for evacuation. However, FED of FDS_EVAC has some problem of application because it dose not considers evacuees's gender and age groups but using single subject. In this study, numerical analysis using modified FED which considers gender and age group of evacuees was performed. We investigate the effect of improved FED on the evacuation. We applied evacuation analysis to exhibition centre where the evacuees was set one thousand five hundred people. The FED is increasing with children 2%, male 17%, female 4%, adult 13% and elderly people 22%. Fatality is increasing due to increased FED.

Short-term protein intake increases fractional synthesis rate of muscle protein in the elderly: meta-analysis

  • Gweon, Hyun-Soo;Sung, Hee-Ja;Lee, Dae-Hee
    • Nutrition Research and Practice
    • /
    • 제4권5호
    • /
    • pp.375-382
    • /
    • 2010
  • The precise effects of protein intake on fractional synthesis rate (FSR) of muscle protein are still under debate. The sample size of these studies was small and the conclusions in young and elderly subjects were inconsistent. To assess the effect of dietary protein intake on the FSR level, we conducted a meta-analysis of controlled protein intake trials. Random-effects models were used to calculate the weighted mean differences (WMDs). Ten studies were included and effects of short-term protein intake were evaluated. In an overall pooled estimate, protein intake significantly increased the FSR (20 trials, 368 participants; WMD: 0.025%/h; 95%CI: 0.019-0.031; P < 0.0001). Meta-regression analysis suggested that the protein dose was positively related to the effect size (regression coefficient = 0.108%/h; 95%CI: 0.035, 0.182; P = 0.009). A subgroup analysis indicated that protein intake significantly increased FSR when the protein dose was ${\leq}$ 0.80 g/kg BW (16 trials, 308 participants; WMD: 0.027%/h; 95%CI: 0.019-0.031; P < 0.0001), but did not affect FSR when the protein dose was > 0.80 g/kg BW (4 trials, 60 participants; WMD: 0.016%/h; 95%CI: 0.004-0.029; P = 0.98). In conclusion, this study is the first integrated results showing that a short-term protein intake is effective at improving the FSR of muscle protein in the healthy elderly as well as young subjects. This beneficial effect seems to be dose-dependent when the dose levels of protein range from 0.08 to 0.80 g/kg BW.

FDS를 이용한 화재시 연소가스의 독성평가에 관한 비교 연구 (A Comparative Study on the Toxicity Evaluation for Fire Smoke by FDS)

  • 정범진;이근원
    • 한국가스학회지
    • /
    • 제19권1호
    • /
    • pp.38-44
    • /
    • 2015
  • FDS (Fire Dynamics Simulator)는 화재안전공학 분야에서 가장 널리 사용되는 전산유체역학 소프트웨어로서 화재의 성장과 영향에 대한 다양한 평가에 응용될 수 있다. 본 연구에서는 화재시 발생하는 연소가스의 독성을 평가할 수 있는 유효복용분량 (Fractional Effective Dose, FED)와 유효부분농도 (Fractional Effective Concentration, FEC) 수준을 예측하기 위하여 FDS 시뮬레이션에서 얻어진 다양한 결과를 활용하였다. 그러나 FDS에서 기본적으로 제공하는 출력값으로는 이러한 값을 직접적으로 구할 수 없으므로, 피난 시뮬레이션에서 얻어진 결과를 결부시켜 별도의 계산과정을 통하여 FED와 FEC 수준을 계산하였다. 특히, 2013년 11월에 FDS의 버전이 업데이트된 바 있어 본 연구에서는 동일한 조건에 대하여 FDS의 구버전과 신버전을 비교하여 시뮬레이션 하였으며, 그 결과 FED, FEC값에 있어서 두 버전사이에 평균 약 10%의 차이가 발생함을 확인 할 수 있었다.

Stereotactic Body Radiation Therapy in Canine Nasal Transitional Cell Carcinoma

  • Park, Noh-won;Lee, Dong-han;Huh, Ra-young;Han, Jae-woong;Eom, Ki-dong
    • 한국임상수의학회지
    • /
    • 제34권4호
    • /
    • pp.299-303
    • /
    • 2017
  • An 11-year-old neutered male Maltese presented for radiation therapy for nasal transitional cell carcinoma. Stereotactic body radiation therapy (SBRT) was provided for the owner's request. Clinical signs improved 6 days after radiation therapy. Adverse effects including alopecia and pigmentation on the facial region were observed at 21 days after radiation therapy. The first follow-up computed tomography (CT) 96 days after SBRT revealed that the nasal tumor had decreased by 60.63% compared with the pre-treatment volume. Clinical signs related with the tumor reassigned 151 days after SBRT, and the second follow-up CT revealed tumor relapse. The patient was died 238 days after SBRT due to tumor relapse. SBRT showed a good tumor control effect with relatively mild radiation toxicity relative to other radiation therapy modalities, in accordance with a previous study. Further studies are needed to establish an effective treatment protocol, such as total dose, fractional dose, and inter-fractional period, in canine malignant nasal tumors.

Anti-Salmonella Activity of Lemongrass Oil Alone and in Combination with Antibiotics

  • Shin, Seung-Won
    • Natural Product Sciences
    • /
    • 제11권3호
    • /
    • pp.160-164
    • /
    • 2005
  • The effects of Cymbopogon citratus essential oil (Lemongrass oil) and its main component, citral (84.30%), on antibiotic-susceptible and -resistant strains of Salmonella enteritidis and S. typhimurium were assessed. C. citratus oil and citral significantly inhibited all strains of the two Salmonella species examined, with minimum inhibiting concentrations (MICs) ranging from 0.5 mg/ml to 8.0 mg/ml. The combined effects of C. citratus oil and citral (84.30%) were evaluated using a checkerboard microtiter assay. Essential oil fractions of C. citratus and citral exhibited strong synergistic or additive effects with streptomycin or kanamycin against S. typhimurium strains with fractional inhibitory concentration (FIC) indices in the range of 0.28 to 1.00. In conclusion, a combination of streptomycin and lemongrass oil or its main component, citral, may be useful for reducing the minimum effective dose of antibiotic required for the treatment of resistant S. typhimurium infections.

도로터널 위험도 평가프로그램 개발에 관한 연구(I) (The study of development of quantitative risk assesment program for the road tunnel)

  • 유지오;신현준;이동호
    • 대한설비공학회:학술대회논문집
    • /
    • 대한설비공학회 2006년도 하계학술발표대회 논문집
    • /
    • pp.460-467
    • /
    • 2006
  • Some large accidents in tunnels in recent years, such as Mont Blanc, Gotthard and Tauern tunnels, have lead to an increasing attention for tunnel safety and necessity of tool for quantitative risk assesment of road tunnel. And the purpose of this study is to develop the quantitative risk assesment tool for the application of road tunnel. The objectives of this paper are as follows : (1) analyze of traffic accident rates in tunnel, (2) make out scenario for fire accidents, (3) develop the evacuation model and FED calculation model, (4) Present the results from quantitative risk assesment for the model tunnel according with the fire heat release rates and distances of cross passage.

  • PDF

목재 기반 소재의 연소생성물 노출 실험을 통한 독성요인 분석 (Toxicity Factor Analysis through the Exposure Experiment of the Combustion Products on Wood-Based Materials)

  • 김남균;박정호;조남욱
    • 한국화재소방학회논문지
    • /
    • 제30권6호
    • /
    • pp.57-63
    • /
    • 2016
  • 본 연구에서는 목재 기반 소재(MDF, OSB)의 연소생성물의 독성을 동물실험 기법을 사용하여 분석하였다. 실험용 쥐의 평균행동정지시간은 MDF가 OSB에 비해 짧았다. 이는 MDF 연소생성물의 독성이 OBS보다 높음을 의미한다. 해당 결과의 요인을 정량적으로 분석하기 위해 FT-IR을 통한 가스상 물질 분석을 수행하였다. 정성분석 결과 CO와 $CO_2$가 발생됨을 확인하였으며, 정량분석 결과 가스발생량은 OSB가 MDF보다 높음을 확인하였다. 또한 실험 후 실험용 쥐의 혈액분석 결과 OSB가 MDF에 비해 COHb 농도가 높음으로써, 가스상 물질의 발생량과 COHb 농도가 상관성이 있음을 확인하였다. 현재 재료의 연소생성물 독성 분석은 독성지수 Fractional Effective Dose (FED)를 통해 이루어지고 있다. FED는 독성가스 발생량을 기반으로 하고 있으며, 노출 물질의 독성이 높을수록 평균행동정지시간은 짧아진다. 하지만 본 연구 결과에서는 OSB가 MDF에 비하여 CO 발생량은 186.5%, COHb는 > 129.6% 임에도 불구하고 평균행동 정지시간이 51초가량 길게 나타남을 확인함으로써, 연소생성물 중 가스상 물질 이외의 추가적인 독성 요인에 대한 연구가 요구됨을 확인하였다.

연소 독성 기반 우레탄 화재의 위험성 평가 연구 (A Research of Risk Assessment for Urethane Fire Based on Fire Toxicity)

  • 김성수;조남욱;이동호
    • 한국화재소방학회논문지
    • /
    • 제29권2호
    • /
    • pp.73-78
    • /
    • 2015
  • 리스크 관리 대상 중 화재는 대형재해임과 동시에 물적 인적 손실을 동반하는 고위험군 항목에 속한다. 따라서 재난안전관리에서는 실천적 측면에서의 화재예방활동과 발생 가능한 화재위험성 예측, 화재 피해 최소화를 위한 안전관리비용 투자가 요구되며 인적피해 최소화를 위해 가스 유해성 시험(KS F 2271)기반 연소 독성에 대한 위험성 평가를 요구한다. 본 연구에서는 정량적 화재위험성평가 기법의 기초 데이터 확보를 위한 연구로, 두께 5~25 mm의 우레탄 시료를 대상으로 가스 유해성 시험을 실시하였다. 또한 실험동물에 노출되는 연소생성물은 적외선 분광분석기(FT-IR)로 분석하여 ISO 13344의 연소독성지수 Lethal Fractional Effective Dose ($L_{FED}$)를 산출하였다. 또한, $L_{FED}$에 기초하여 시료의 Lethal Concentration 50% ($LC_{50}$)을 산정한 결과, 일정치 이상의 화재하중을 가지는 우레탄 시료의 $LC_{50}$$118{\sim}129g/m^3$임을 확인하였다. 본 연구를 통하여 해당 기법이 우레탄 화재 위험성 분석에 적용 가능함을 확인하였으며, 본 기법의 적용으로부터 유해가스에 의한 인적피해 예측을 기반으로한 건축물 안전 확보 차원의 전략적 투자확대의 자료로 활용 가능케 하였다.