• Title/Summary/Keyword: Fractional effective dose

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

  • Yoo, Ji-Oh;Shin, Hyun-Jun;Nam, Chang-Ho
    • Proceedings of the SAREK Conference
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    • 2008.06a
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    • pp.474-479
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    • 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.

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

  • Lee, Kwangjae;Lee, Youn-Sung
    • Journal of Sensor Science and Technology
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    • v.25 no.6
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    • pp.394-398
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    • 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.

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

  • Kim, Hong Jin;Bae, Sung-Yong;Choi, Young Ki;Hong, Ki Bae;Ryou, Hong Sun
    • Journal of the Korean Society of Safety
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    • v.28 no.1
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    • pp.125-131
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    • 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
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    • v.4 no.5
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    • pp.375-382
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    • 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.

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

  • Jeong, Beom Jin;Lee, Keun Won
    • Journal of the Korean Institute of Gas
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    • v.19 no.1
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    • pp.38-44
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    • 2015
  • FDS (Fire Dynamics Simulator) is the most widely used computational fluid dynamics software in the fire safety engineering community, and it is applicable to various evaluations of fire growth and its effects. This study made use of a range of outputs from FDS simulation to predict FED (Fractional Effective Concentration) and FEC (Fractional Effective Concentration) levels which are often adopted to evaluate toxicity of fire smoke. As it is not possible to calculate these values directly from outputs of FDS, it was necessary to produce them by means of additional calculation procedures incorporating results of evacuation simulation. In this study, the latest version of FDS, which was recently updated in November 2013, was utilized for the purpose of quantitative comparison with the old version of FDS. As a result, it was found that they make about 10 percent difference on average in predicting FED and FEC levels for the cable fire case study.

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
    • Journal of Veterinary Clinics
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    • v.34 no.4
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    • pp.299-303
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    • 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
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    • v.11 no.3
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    • pp.160-164
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    • 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.

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

  • Yoo, Ji-Oh;Shin, Hyun-Jun;Rie, Dong-Ho
    • Proceedings of the SAREK Conference
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    • 2006.06a
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    • pp.460-467
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    • 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.

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

  • Kim, Nam-Kyun;Park, Jeong-Ho;Cho, Nam-Wook
    • Fire Science and Engineering
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    • v.30 no.6
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    • pp.57-63
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    • 2016
  • In this study, the toxicity of combustion products of wood-based materials (MDF, OSB) were analyzed using experimental animal techniques. The average deed stopping time of MDF was shorter than that of OSB. This means that the toxicity of the combustion products of MDF is higher than that of OSB. To analyze the cause of the result quantitatively, Fourier transform infrared spectroscopy (FT-IR) of the gas phase materials was performed. Qualitative analysis result, CO and $CO_2$ were detected. Quantitative analysis results, the gas generation rate was higher in OSB than in MDF. Blood analysis of mice revealed, COHb to be higher in OSB than MDF. A correlation between the gas generation rate and COHb was found. Currently, the toxicity of the combustion products of the materials is being examined using the toxicity index, such as Fractional Effective Dose (FED). The FED is based on the gas emissions. The average deed stopping time decreased with increasing toxicity of exposed material. On the other hand, the result of this study showed that, the CO emissions of OBS were 186.5% that of MDF. The COHb of OSB was > 129.6% that of MDF. Nevertheless, the average deed stopping time of the OSB is 51 seconds longer than that of MDF. Therefore, more toxicity studies on factors other than the gas phase materials in the combustion products will be needed.

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

  • Kim, Sung-Soo;Cho, Nam-Wook;Rie, Dong-Ho
    • Fire Science and Engineering
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    • v.29 no.2
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    • pp.73-78
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    • 2015
  • Fire in the risk management subject belongs to high risk disaster which accompanies personnel and materiel loss. So, management of disaster and safety is required to include fire prevention activities, fire risk prediction and investment of safety management expense. Combustion toxicity is required by gas toxicity test (KS F 2271), to minimize human damage. In this study, gas toxicity test were experimented with regard to urethane sample (Depth 5~25 mm) to obtain basic data. Fire effluent exposing to experimental animal were analyzed by FT-IR (Fourier transform infrared spectroscopy). Combustion toxicity index Lethal Fractional Effective Dose ($L_{FED}$) of ISO 13344 was calculated. According to the result of calculating Lethal Concentration 50% ($LC_{50}$) based on $L_{FED}$, $LC_{50}$ of urethane sample containing certain level of fire load is confirmed as $118{\sim}129g/m^3$. Through this study, applicability of this method was confirmed for fire risk assessment. This method can provide information to predict human damage by toxicity combustion gas for securing safety.