Incidence of lung cancer among subway drivers in Stockholm.

Science.gov (United States)

Gustavsson, Per; Bigert, Carolina; Pollán, Marina

2008-07-01

Very high levels of airborne particles have been detected in the subway system in Stockholm. Subway particles are more toxic to DNA in cultured human lung cells than particles from ambient air. This cohort comprised all men in Stockholm County who were gainfully employed in 1970. They were followed for cancer incidence until 1989. Lung cancer cases were identified from the national cancer register. Subway drivers were identified from the census in 1970. The reference cohort comprised all transport and communication workers in Stockholm. There were nine cases of lung cancer among the subway drivers, giving a SIR of 0.82 (95% confidence interval 0.38-1.56). The lung cancer incidence was not increased among the subway drivers. The study gives some evidence against the hypothesis that subway particles would be more potent in inducing lung cancer than particles in ambient air. (c) 2008 Wiley-Liss, Inc.

Health effects of a subway environment in healthy volunteers.

Science.gov (United States)

Klepczyńska Nyström, A; Svartengren, M; Grunewald, J; Pousette, C; Rödin, I; Lundin, A; Sköld, C M; Eklund, A; Larsson, B-M

2010-08-01

Environmental particle exposure, often estimated as the particulate mass of particles with a diameter subway environment. 20 healthy volunteers were exposed to a subway and a control environment for 2 h, followed by measurements of lung function and the inflammatory response in the lower airways (bronchoscopy) and in the peripheral blood. No cellular response was found in the airways after exposure to the subway environment. In the blood, we found a statistically significant increase in fibrinogen and regulatory T-cells expressing CD4/CD25/FOXP3. Subway and road tunnel environments have similar levels of PM(10) and PM(2.5), whilst the concentrations of ultrafine particles, nitrogen monoxide and dioxide are lower in the subway. Although no cellular response was detected, the findings indicate a biological response to the subway environment. Our studies show that using gravimetric estimates of ambient particulate air pollution alone may have clear limitations in health-risk assessment.

Dynamics of subway networks based on vehicles operation timetable

Science.gov (United States)

Xiao, Xue-mei; Jia, Li-min; Wang, Yan-hui

2017-05-01

In this paper, a subway network is represented as a dynamic, directed and weighted graph, in which vertices represent subway stations and weights of edges represent the number of vehicles passing through the edges by considering vehicles operation timetable. Meanwhile the definitions of static and dynamic metrics which can represent vertices' and edges' local and global attributes are proposed. Based on the model and metrics, standard deviation is further introduced to study the dynamic properties (heterogeneity and vulnerability) of subway networks. Through a detailed analysis of the Beijing subway network, we conclude that with the existing network structure, the heterogeneity and vulnerability of the Beijing subway network varies over time when the vehicle operation timetable is taken into consideration, and the distribution of edge weights affects the performance of the network. In other words, although the vehicles operation timetable is restrained by the physical structure of the network, it determines the performances and properties of the Beijing subway network.

Comparison of safety equipment between London underground and Beijing subway

Science.gov (United States)

Chen, T.; Zhang, S. Y.; Zhao, L. Z.; Xia, J. J.; Fu, X. C.; Bao, Z. M.; Chen, Y.; Zhang, X. Z.; Wang, R. J.; Hu, C.; Jing, L. S.; Wang, Y.

2017-06-01

The purpose of this paper was to improve the safety equipment’s effectiveness through the comparison. Firstly, the history and safety accident of London Underground and Beijing Subway were shown. Secondly, fire equipment between these two cities was compared including station’s hardware installations and carriage’s hardware installations. Thirdly, the relative software installations were also compared such as emergency drills. The results showed that Beijing Subway’s hardware installations were better than London. However, London Underground’s some installations were more effective than Beijing. Both cities would pay more attention on anti-terrorist in tunnel.

Random matrices and the New York City subway system

OpenAIRE

Jagannath, Aukosh; Trogdon, Thomas

2017-01-01

We analyze subway arrival times in the New York City subway system. We find regimes where the gaps between trains exhibit both (unitarily invariant) random matrix statistics and Poisson statistics. The departure from random matrix statistics is captured by the value of the Coulomb potential along the subway route. This departure becomes more pronounced as trains make more stops.

Patterns of suicidal behaviour in a metro subway system: a study of 306 cases injured by the Munich subway, 1980-1999.

Science.gov (United States)

Ladwig, Karl-Heinz; Baumert, Jens J

2004-09-01

As a basis for preventive strategies to reduce subway suicides, an investigation was undertaken to determine if there was a distinct pattern of subway suicidal behaviour. Data were taken from the Municipal Munich Subway System case registry (southern Germany) for all suicidal incidents on the track: purposely inflicted; date, time and location of incident, sex of victim, outcome. The analysis covered a 20 year observation period between 1980 and 1999, for which the Munich Municipal Office for Statistics also provided data of all deaths due to suicides within the city area of Munich. Suicide mortality was classified by the International Classification of Diseases, Ninth revision (codes E950-E959). A total of 306 incidents were documented with an annual mean of 16.5 cases. Case fatality was 66% (n=202). It was highest in winter and in higher aged groups. No significant time trend for incidences was observed. Median age of suicide attempters was 38 years. Most incidences (24.2%) were recorded for persons aged 20-29 years. The male: female ratio was 1.15 : 1. The peak time of day for incidences in women was during the late morning hours while significantly more men committed subway suicides during evening hours (p=0.001). No consistent seasonal variation was observed. In comparison to average suicide attempters, subjects committing subway suicides are markedly younger and they follow to a lesser extent established seasonal or circadian time patterns. More women are involved in subway suicides than would be expected. However, similarities to reports on behavioural patterns of subway suicides in other communities are striking.

Adolescent Purchasing Behavior at McDonald's and Subway.

Science.gov (United States)

Lesser, Lenard I; Kayekjian, Karen C; Velasquez, Paz; Tseng, Chi-Hong; Brook, Robert H; Cohen, Deborah A

2013-10-01

To assess whether adolescents purchasing food at a restaurant marketed as "healthy" (Subway) purchase fewer calories than at a competing chain (McDonald's). We studied 97 adolescents who purchased a meal at both restaurants on different days, using each participant as his or her control. We compared the difference in calories purchased by adolescents at McDonald's and Subway in a diverse area of Los Angeles, CA. Adolescents purchased an average of 1,038 calories (standard error of the mean [SEM]: 41) at McDonald's and 955 calories (SEM 39) at Subway. The difference of 83 calories (95% confidence interval [CI]: -20 to 186) was not statistically significant (p = .11). At McDonald's, participants purchased significantly more calories from drinks (151 vs. 61, p McDonald's vs. 35 at Subway, p McDonald's (.15 vs. .57 cups, p McDonald's. Although Subway meals had more vegetables, meals from both restaurants are likely to contribute to overeating. Copyright © 2013 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

Random matrices and the New York City subway system

Science.gov (United States)

Jagannath, Aukosh; Trogdon, Thomas

2017-09-01

We analyze subway arrival times in the New York City subway system. We find regimes where the gaps between trains are well modeled by (unitarily invariant) random matrix statistics and Poisson statistics. The departure from random matrix statistics is captured by the value of the Coulomb potential along the subway route. This departure becomes more pronounced as trains make more stops.

Epidemiology of subway-related fatalities in New York City, 1990-2003.

Science.gov (United States)

Gershon, Robyn R M; Pearson, Julie M; Nandi, Vijay; Vlahov, David; Bucciarelli-Prann, Angela; Tracy, Melissa; Tardiff, Kenneth; Galea, Sandro

2008-01-01

Subway transit is a relatively safe mode of transportation, yet compared to all other forms of mass transit in the United States (U.S.), subways have the highest fatality rate. The aim of this paper is to characterize subway-related fatalities in order to identify opportunities for risk reduction. Medical examiner records for all New York City (NYC) subway-related deaths (1990-2003) were reviewed. Data were abstracted on decedents' demographics and autopsy findings, including laboratory findings. There were 668 subway-related fatalities, of these, 10 (1.5%) were homicides, 343 (51.3%) were determined to be suicides, and 315 (47.2%) were accidental. Although decedent characteristics varied between fatality categories, they were not particularly informative with regard to prevention. Prevention strategies that focus on structural controls are likely to be most efficacious in improving the overall safety of the NYC subway systems. These findings suggest that structural rather than individual-level interventions would be most successful in preventing subway fatalities.

Indoor-air microbiome in an urban subway network: diversity and dynamics.

Science.gov (United States)

Leung, Marcus H Y; Wilkins, David; Li, Ellen K T; Kong, Fred K F; Lee, Patrick K H

2014-11-01

Subway systems are indispensable for urban societies, but microbiological characteristics of subway aerosols are relatively unknown. Previous studies investigating microbial compositions in subways employed methodologies that underestimated the diversity of microbial exposure for commuters, with little focus on factors governing subway air microbiology, which may have public health implications. Here, a culture-independent approach unraveling the bacterial diversity within the urban subway network in Hong Kong is presented. Aerosol samples from multiple subway lines and outdoor locations were collected. Targeting the 16S rRNA gene V4 region, extensive taxonomic diversity was found, with the most common bacterial genera in the subway environment among those associated with skin. Overall, subway lines harbored different phylogenetic communities based on α- and β-diversity comparisons, and closer inspection suggests that each community within a line is dependent on architectural characteristics, nearby outdoor microbiomes, and connectedness with other lines. Microbial diversities and assemblages also varied depending on the day sampled, as well as the time of day, and changes in microbial communities between peak and nonpeak commuting hours were attributed largely to increases in skin-associated genera in peak samples. Microbial diversities within the subway were influenced by temperature and relative humidity, while carbon dioxide levels showed a positive correlation with abundances of commuter-associated genera. This Hong Kong data set and communities from previous studies conducted in the United States formed distinct community clusters, indicating that additional work is required to unravel the mechanisms that shape subway microbiomes around the globe. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Bioaerosols in the Barcelona subway system.

Science.gov (United States)

Triadó-Margarit, X; Veillette, M; Duchaine, C; Talbot, M; Amato, F; Minguillón, M C; Martins, V; de Miguel, E; Casamayor, E O; Moreno, T

2017-05-01

Subway systems worldwide transport more than 100 million people daily; therefore, air quality on station platforms and inside trains is an important urban air pollution issue. We examined the microbiological composition and abundance in space and time of bioaerosols collected in the Barcelona subway system during a cold period. Quantitative PCR was used to quantify total bacteria, Aspergillus fumigatus, influenza A and B, and rhinoviruses. Multitag 454 pyrosequencing of the 16S rRNA gene was used to assess bacterial community composition and biodiversity. The results showed low bioaerosol concentrations regarding the targeted microorganisms, although the bacterial bioburden was rather high (10 4 bacteria/m 3 ). Airborne bacterial communities presented a high degree of overlap among the different subway environments sampled (inside trains, platforms, and lobbies) and were dominated by a few widespread taxa, with Methylobacterium being the most abundant genus. Human-related microbiota in sequence dataset and ascribed to potentially pathogenic bacteria were found in low proportion (maximum values below 2% of sequence readings) and evenly detected. Hence, no important biological exposure marker was detected in any of the sampled environments. Overall, we found that commuters are not the main source of bioaerosols in the Barcelona subway system. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Analysis of Subway Interior Noise at Peak Commuter Time.

Science.gov (United States)

Lee, Donguk; Kim, Gibbeum; Han, Woojae

2017-07-01

Although mass transit systems are convenient and efficient for urban people, little attention has been paid to the potential hearing hazard from their noise. The purpose of the current study was to measure and analyze levels of subway interior noise at peak commuter times and to provide information about commuters' daily dose of noise exposure. To measure the subway interior noise, nine subway lines inside Seoul (i.e., lines 1-9) and six lines surrounding the capital city area (i.e., Central, Bundang, Sinbundang, Incheon, Gyeongui, and Gyeongchun) were chosen. The noise was measured and recorded by a sound level meter for two-hour periods in the morning and evening. 1) In the LZeq analysis, the average noise level of all 15 lines was 72.78 dB; the maximum and minimum noise levels were 78.34 and 62.46 dB, respectively. The average noise level of the nine lines inside Seoul was 73.45 dB, which was 1.68-dB louder than that of the six lines surrounding the capital city area. 2) Based on the LZeq analysis of 33 measured frequencies, 12.5 Hz was the highest frequency and 20,000 Hz was the lowest. 3) There was no remarkable difference in the level of subway interior noise between morning and evening peak commuter times. We concluded that the level of subway interior noise was not loud enough for commuters to incur noise-induced hearing loss. Regardless, environmental noise control efforts in the subway system might be needed for commuters who take a subway every day.

A model for dispersion of contaminants in the subway environment

Energy Technology Data Exchange (ETDEWEB)

Coke, L. R.; Sanchez, J. G.; Policastro, A. J.

2000-05-03

Although subway ventilation has been studied extensively, very little has been published on dispersion of contaminants in the subway environment. This paper presents a model that predicts dispersion of contaminants in a complex subway system. It accounts for the combined transient effects of train motion, station airflows, train car air exchange rates, and source release properties. Results are presented for a range of typical subway scenarios. The effects of train piston action and train car air exchange are discussed. The model could also be applied to analyze the environmental impact of hazardous materials releases such as chemical and biological agents.

What Makes Urban Transportation Efficient? Evidence from Subway Transfer Stations in Korea

Directory of Open Access Journals (Sweden)

Changhee Kim

2017-11-01

Full Text Available Subway stations have been proliferating underneath cosmopolitan metropolises with subway lines forming complex webs connected in strategic transfer stations. The efficiency of the subway system thus heavily weighs on the efficiency at these transfer stations. However, few studies have been conducted on transfer efficiency at transfer stations due to the complexities involved. As the first study of its kind in the subway context, we analyze the transfer efficiency of the subway transfer stations in Seoul, one of the megacities in the world, and demonstrate how transfer efficiency can be analyzed using bootstrap-based DEA technique. Based on the results, we discuss the reasons behind the inefficiency of subway transfer stations and possible ways to improve them into efficient decision-making units.

Exposure to airborne particulate matter in the subway system.

Science.gov (United States)

Martins, Vânia; Moreno, Teresa; Minguillón, María Cruz; Amato, Fulvio; de Miguel, Eladio; Capdevila, Marta; Querol, Xavier

2015-04-01

The Barcelona subway system comprises eight subway lines, at different depths, with different tunnel dimensions, station designs and train frequencies. An extensive measurement campaign was performed in this subway system in order to characterise the airborne particulate matter (PM) measuring its concentration and investigating its variability, both inside trains and on platforms, in two different seasonal periods (warmer and colder), to better understand the main factors controlling it, and therefore the way to improve air quality. The majority of PM in the underground stations is generated within the subway system, due to abrasion and wear of rail tracks, wheels and braking pads caused during the motion of the trains. Substantial variation in average PM concentrations between underground stations was observed, which might be associated to different ventilation and air conditioning systems, characteristics/design of each station and variations in the train frequency. Average PM2.5 concentrations on the platforms in the subway operating hours ranged from 20 to 51 and from 41 to 91 μg m(-3) in the warmer and colder period, respectively, mainly related to the seasonal changes in the subway ventilation systems. The new subway lines with platform screen doors showed PM2.5 concentrations lower than those in the conventional system, which is probably attributable not only to the more advanced ventilation setup, but also to the lower train frequency and the design of the stations. PM concentrations inside the trains were generally lower than those on the platforms, which is attributable to the air conditioning systems operating inside the trains, which are equipped with air filters. This study allows the analysis and quantification of the impact of different ventilation settings on air quality, which provides an improvement on the knowledge for the general understanding and good management of air quality in the subway system. Copyright © 2014 The Authors. Published by

[Study on transition metals in airborne particulate matter in Shanghai city's subway].

Science.gov (United States)

Bao, Liang-Man; Lei, Qian-Tao; Tan, Ming-Guang; Li, Xiao-Lin; Zhang, Gui-Lin; Liu, Wei; Li, Yan

2014-06-01

PM10 and PM2.5 aerosol particle samples were collected at a subway station in Shanghai and their morphology, chemical composition and transition metal species were studied. The mass concentrations of PM10 and PM2.5 inside the subway station were significantly higher than those measured in aboveground ambient air. The PM levels inside subway were much higher than the state control limit. The aerosol composition in the metro station was quite different from that of the aboveground urban particles. Concentrations of Fe, Mn and Cr were higher than the averages of aboveground urban air particles by factors of 8, 2, and 2, respectively, showing a substantial enrichment in subway. Scanning electron microscope (SEM) analysis showed that the subway particles had flat surfaces in combination with parallel scratches and sharp edges and looked like metal sheets or flakes. Furthermore, analysis of the atomic composition of typical subway particles by energy dispersive X-Ray (EDX) spectroscopy showed that oxygen and iron dominated the mass of the particles. The X-ray absorption near-edge structure (XANES) spectroscopy results showed that a fraction (> 26%) of the total iron in the PM10 was in the form of pure Fe, while in the street particles Fe(III) was shown to be a significant fraction of the total iron. The work demonstrated that the underground subway stations in Shanghai were an important microenvironment for exposure to transition metal aerosol for the people taking subway train for commuting every day and those who work in the subway stations, and the metal particle exposure for people in the subway station should not be ignored.

Examining the Interaction of Taxi and Subway Ridership for Sustainable Urbanization

Directory of Open Access Journals (Sweden)

Miaoyi Li

2017-02-01

Full Text Available A transit ridership study is an essential part of sustainability, and can provide a deep understanding of people’s travel patterns for efficient transportation development and urbanization. However, there is a lack of empirical studies comparing subway and taxi services, and their interactions within a city, that is to say, the interdependent transportation networks. Incorporating new data, this study aims to examine the spatial variation of urban taxi ridership due to the impacts of a new subway line operation opened in 2014 in Wuxi, China. We examine the spatial patterns and interactions of ridership in Wuxi by integrating taxi trajectory from GPS data and subway data from continuously collected fare transactions. The results indicated that the demand for taxi and subway usage is quite elastic with respect to both location and time, and the new subway’s opening had more influence on areas adjacent to subway stations and urban center-suburban travel. Furthermore, increases in travel time and distance would increase the demand for subway, while taxi trips largely represented movements for those locations that the subway could not reach. This paper betters the understanding of travel patterns through large volumes of transportation data for sustainable urbanization policy design.

Reducing the impact of speed dispersion on subway corridor flow.

Science.gov (United States)

Qiao, Jing; Sun, Lishan; Liu, Xiaoming; Rong, Jian

2017-11-01

The rapid increase in the volume of subway passengers in Beijing has necessitated higher requirements for the safety and efficiency of subway corridors. Speed dispersion is an important factor that affects safety and efficiency. This paper aims to analyze the management control methods for reducing pedestrian speed dispersion in subways. The characteristics of the speed dispersion of pedestrian flow were analyzed according to field videos. The control measurements which were conducted by placing traffic signs, yellow marking, and guardrail were proposed to alleviate speed dispersion. The results showed that the methods of placing traffic signs, yellow marking, and a guardrail improved safety and efficiency for all four volumes of pedestrian traffic flow, and the best-performing control measurement was guardrails. Furthermore, guardrails' optimal position and design measurements were explored. The research findings provide a rationale for subway managers in optimizing pedestrian traffic flow in subway corridors. Copyright © 2017. Published by Elsevier Ltd.

Development of the Human Error Management Criteria and the Job Aptitude Evaluation Criteria for Rail Safety Personnel

Energy Technology Data Exchange (ETDEWEB)

Koo, In Soo; Seo, Sang Mun; Park, Geun Ok (and others)

2008-08-15

It has been estimated that up to 90% of all workplace accidents have human error as a cause. Human error has been widely recognized as a key factor in almost all the highly publicized accidents, including Daegu subway fire of February 18, 2003 killed 198 people and injured 147. Because most human behavior is 'unintentional', carried out automatically, root causes of human error should be carefully investigated and regulated by a legal authority. The final goal of this study is to set up some regulatory guidance that are supposed to be used by the korean rail organizations related to safety managements and the contents are : - to develop the regulatory guidance for managing human error, - to develop the regulatory guidance for managing qualifications of rail drivers - to develop the regulatory guidance for evaluating the aptitude of the safety-related personnel.

Development of the Human Error Management Criteria and the Job Aptitude Evaluation Criteria for Rail Safety Personnel

International Nuclear Information System (INIS)

Koo, In Soo; Seo, Sang Mun; Park, Geun Ok

2008-08-01

It has been estimated that up to 90% of all workplace accidents have human error as a cause. Human error has been widely recognized as a key factor in almost all the highly publicized accidents, including Daegu subway fire of February 18, 2003 killed 198 people and injured 147. Because most human behavior is 'unintentional', carried out automatically, root causes of human error should be carefully investigated and regulated by a legal authority. The final goal of this study is to set up some regulatory guidance that are supposed to be used by the korean rail organizations related to safety managements and the contents are : - to develop the regulatory guidance for managing human error, - to develop the regulatory guidance for managing qualifications of rail drivers - to develop the regulatory guidance for evaluating the aptitude of the safety-related personnel

Chlorine Dioxide Fumigation of Subway Materials ...

Science.gov (United States)

Report This bench scale study observed that a six (6) log reduction in viable spores of a suitable B. anthracis surrogate can be obtained for subway infrastructure materials by ClO2 fumigation if the temperature is at or above 24 °C combined with RH greater than 75%. No six log reduction in viable spores was observed at realistic (winter) temperatures in a subway environment (11-13 °C and 70-80% RH) for periods of fumigation that are otherwise efficacious at 24 °C/ 75% RH.

Labelling subway lines

NARCIS (Netherlands)

Garrido, M.A.; Iturriaga, C.; Márquez, A.; Portillo, J.R.; Reyes, P.; Wolff, A.; Eades, P.; Takaoka, T.

2001-01-01

Graphical features on map, charts, diagrams and graph drawings usually must be annotated with text labels in order to convey their meaning. In this paper we focus on a problem that arises when labeling schematized maps, e.g. for subway networks. We present algorithms for labeling points on a line

Network structure of subway passenger flows

Science.gov (United States)

Xu, Q.; Mao, B. H.; Bai, Y.

2016-03-01

The results of transportation infrastructure network analyses have been used to analyze complex networks in a topological context. However, most modeling approaches, including those based on complex network theory, do not fully account for real-life traffic patterns and may provide an incomplete view of network functions. This study utilizes trip data obtained from the Beijing Subway System to characterize individual passenger movement patterns. A directed weighted passenger flow network was constructed from the subway infrastructure network topology by incorporating trip data. The passenger flow networks exhibit several properties that can be characterized by power-law distributions based on flow size, and log-logistic distributions based on the fraction of boarding and departing passengers. The study also characterizes the temporal patterns of in-transit and waiting passengers and provides a hierarchical clustering structure for passenger flows. This hierarchical flow organization varies in the spatial domain. Ten cluster groups were identified, indicating a hierarchical urban polycentric structure composed of large concentrated flows at urban activity centers. These empirical findings provide insights regarding urban human mobility patterns within a large subway network.

Oxidative potential of subway PM2.5

Science.gov (United States)

Moreno, Teresa; Kelly, Frank J.; Dunster, Chrissi; Oliete, Ana; Martins, Vânia; Reche, Cristina; Minguillón, Maria Cruz; Amato, Fulvio; Capdevila, Marta; de Miguel, Eladio; Querol, Xavier

2017-01-01

Air quality in subway systems is of interest not only because particulate matter (PM) concentrations can be high, but also because of the peculiarly metalliferous chemical character of the particles, most of which differ radically from those of outdoor ambient air. We report on the oxidative potential (OP) of PM2.5 samples collected in the Barcelona subway system in different types of stations. The PM chemical composition of these samples showed typically high concentrations of Fe, Total Carbon, Ba, Cu, Mn, Zn and Cr sourced from rail tracks, wheels, catenaries, brake pads and pantographs. Two toxicological indicators of oxidative activity, ascorbic acid (AA) oxidation (expressed as OPAA μg-1 or OPAA m-3) and glutathione (GSH) oxidation (expressed as OPGSH μg-1 or OPGSH m-3), showed low OP for all samples (compared with outdoor air) but considerable variation between stations (0.9-2.4 OPAA μg-1; 0.4-1.9 OPGSH μg-1). Results indicate that subway PM toxicity is not related to variations in PM2.5 concentrations produced by ventilation changes, tunnel works, or station design, but may be affected more by the presence of metallic trace elements such as Cu and Sb sourced from brakes and pantographs. The OP assays employed do not reveal toxic effects from the highly ferruginous component present in subway dust.

SUBWAY POWER SYSTEMS WITH MODERN SEMICONDUCTOR CONVERTERS AND ENERGY STORAGE DEVICES

Directory of Open Access Journals (Sweden)

O.I. Kholod

2013-02-01

Full Text Available Five subway power systems, a traditional power system and power systems with an active rectifier and an energy storage device, are considered. Estimation of energy loss in the analyzed subway power systems circuits is made.

Prevalence of Diabetes Mellitus and Prediabetes in Dalseong-gun, Daegu City, Korea

Directory of Open Access Journals (Sweden)

Jung-Eun Lee

2011-06-01

Full Text Available BackgroundThe aim of the present study was to determine the population-based prevalence of diabetes mellitus (DM and prediabetes in a rural district of Daegu City, Korea.MethodsBetween August and November 2003, a community-based health survey of adults aged 20 years and older was performed in the rural district of Dalseong-gun in Daegu City. A total of 1,806 of all eligible individuals agreed to participate. Fasting plasma glucose was measured in all participants. Two hour oral glucose tolerance was measured in the 1,773 participants for whom there was neither an established diagnosis of DM nor evidence of DM according to fasting glucose levels. The prevalence of DM and prediabetes was determined according to the 2003 criteria of the American Diabetes Association. Subjects with prediabetes were classified into one of three categories of glucose intolerance: isolated impaired fasting glucose (IFG; isolated impaired glucose tolerance (IGT; or combined IFG and IGT.ResultsThe prevalence of DM was 12.2%. The highest prevalence rates were observed in subjects in their seventies. A total of 34.7% of all subjects who were assigned a diagnosis of DM in the present study had not been diagnosed previously. The prevalence of prediabetes was 22.7%. The highest prevalence rates were observed in subjects in their fifties.ConclusionThe present study identified prevalence rates of 12.2% for DM (age-standardized prevalence rate [ASR], 6.8%, and 22.7% for prediabetes (ASR 18.5%. These results emphasize the need for community health promotion strategies to prevent or delay the onset of DM in individuals with prediabetes.

Culture-independent analysis of aerosol microbiology in a metropolitan subway system.

Science.gov (United States)

Robertson, Charles E; Baumgartner, Laura K; Harris, J Kirk; Peterson, Kristen L; Stevens, Mark J; Frank, Daniel N; Pace, Norman R

2013-06-01

The goal of this study was to determine the composition and diversity of microorganisms associated with bioaerosols in a heavily trafficked metropolitan subway environment. We collected bioaerosols by fluid impingement on several New York City subway platforms and associated sites in three sampling sessions over a 1.5-year period. The types and quantities of aerosolized microorganisms were determined by culture-independent phylogenetic analysis of small-subunit rRNA gene sequences by using both Sanger (universal) and pyrosequencing (bacterial) technologies. Overall, the subway bacterial composition was relatively simple; only 26 taxonomic families made up ~75% of the sequences determined. The microbiology was more or less similar throughout the system and with time and was most similar to outdoor air, consistent with highly efficient air mixing in the system. Identifiable bacterial sequences indicated that the subway aerosol assemblage was composed of a mixture of genera and species characteristic of soil, environmental water, and human skin commensal bacteria. Eukaryotic diversity was mainly fungal, dominated by organisms of types associated with wood rot. Human skin bacterial species (at 99% rRNA sequence identity) included the Staphylococcus spp. Staphylococcus epidermidis (the most abundant and prevalent commensal of the human integument), S. hominis, S. cohnii, S. caprae, and S. haemolyticus, all well-documented human commensal bacteria. We encountered no organisms of public health concern. This study is the most extensive culture-independent survey of subway microbiota so far and puts in place pre-event information required for any bioterrorism surveillance activities or monitoring of the microbiological impact of recent subway flooding events.

Podnikateľský zámer - Subway franchise

OpenAIRE

Leitner, Tomáš

2013-01-01

Subject of this thesis is to create a business plan for the branch of Subway franchise and acquaint with the concept of franchising. Theoretical part of the diploma thesis applies to definition of franchising, its characteristics, features, advantages and disadvantages for both parties and describes the elements necessary for setting up business. In application part of the thesis is introduced the business plan for opening of Subway branch.

Factors associated with suicide ideation among subway drivers in Korea.

Science.gov (United States)

Byun, Junsu; Kim, Hyoung-Ryoul; Lee, Hye-Eun; Kim, Se-Eun; Lee, Jongin

2016-01-01

There were several suicide events of subway drivers in Korea. The aim of this study is to explore work-related factors associated with suicide ideation among subway drivers. We analyzed data from 980 male subway drivers. A section of the Korean version of the Composite International Diagnostic Interview (K-CIDI 2.1) was administered by trained interviewers to judge whether a driver has suicide ideation and to diagnose psychiatric disorders. A questionnaire was also administered to collect data on sociodemographic characteristics, work environments, occupational stress, person under train (PUT) experience, and work-related problems. Occupational stress was examined by using the Korean Occupational Stress Scale (KOSS). Logistic regression was applied to evaluate the association between work-related factors and suicide ideation among subway drivers. Regarding work-related problems, conflict with passengers and sudden stops due to the emergency bell were significantly associated with suicide ideation. MDD, PTSD, and panic disorder were strongly associated with suicide ideation. In the analysis of occupational stress, insufficient job control (OR 2.34) and lack of reward (OR 2.52) were associated with suicide ideation even after being adjusted for psychiatric disorders and other work-related factors. Insufficient job control and lack of reward were associated with suicide ideation among subway drivers. Strategies for drivers to have autonomy while working and to achieve effort-reward balance should be implemented. Furthermore, drivers who have experienced negative work-related problems should be managed appropriately.

[Distribution of airborne fungi, particulate matter and carbon dioxide in Seoul metropolitan subway stations].

Science.gov (United States)

Kim, Ki Youn; Park, Jae Beom; Kim, Chi Nyon; Lee, Kyung Jong

2006-07-01

The aims of this study were to examine the level of airborne fungi and environmental factors in Seoul metropolitan subway stations and to provide fundamental data to protect the health of subway workers and passengers. The field survey was performed from November in 2004 to February in 2005. A total 22 subway stations located at Seoul subway lines 1-4 were randomly selected. The measurement points were subway workers' activity areas (station office, bedroom, ticket office and driver's seat) and the passengers' activity areas (station precincts, inside train and platform). Air sampling for collecting airborne fungi was carried out using a one-stage cascade impactor. The PM and CO2 were measured using an electronic direct recorder and detecting tube, respectively. In the activity areas of the subway workers and passengers, the mean concentrations of airborne fungi were relatively higher in the workers' bedroom and station precinct whereas the concentration of particulate matter, PM10 and PM2.5, were relatively higher in the platform, inside the train and driver's seat than in the other activity areas. There was no significant difference in the concentration of airborne fungi between the underground and ground activity areas of the subway. The mean PM10 and PM2.5 concentration in the platform located at underground was significantly higher than that of the ground (psubway line 1-4 were not serious enough to cause respiratory disease in subway workers and passengers. This indicates that there is little correlation between airborne fungi and particulate matter.

Development of a subway operation incident delay model using accelerated failure time approaches.

Science.gov (United States)

Weng, Jinxian; Zheng, Yang; Yan, Xuedong; Meng, Qiang

2014-12-01

This study aims to develop a subway operational incident delay model using the parametric accelerated time failure (AFT) approach. Six parametric AFT models including the log-logistic, lognormal and Weibull models, with fixed and random parameters are built based on the Hong Kong subway operation incident data from 2005 to 2012, respectively. In addition, the Weibull model with gamma heterogeneity is also considered to compare the model performance. The goodness-of-fit test results show that the log-logistic AFT model with random parameters is most suitable for estimating the subway incident delay. First, the results show that a longer subway operation incident delay is highly correlated with the following factors: power cable failure, signal cable failure, turnout communication disruption and crashes involving a casualty. Vehicle failure makes the least impact on the increment of subway operation incident delay. According to these results, several possible measures, such as the use of short-distance and wireless communication technology (e.g., Wifi and Zigbee) are suggested to shorten the delay caused by subway operation incidents. Finally, the temporal transferability test results show that the developed log-logistic AFT model with random parameters is stable over time. Copyright © 2014 Elsevier Ltd. All rights reserved.

A study on the energy consumption unit of subway stations in Korea

Energy Technology Data Exchange (ETDEWEB)

Hong, Wonhwa [Kyung-Pook National Univ., Daegu (Korea). Dept. of Architecture; Kim, Samuel [Dong-Eui Univ., Busan (Korea). Dept. of Building Systems Engineering

2004-12-01

As the Korean economy and society continues to develop, the number of subways are expected to increase. This increase will demand greater heating and cooling energy as well as convey a sharp rise in the overall energy consumption. This study aims to develop energy conservation and analysis for subways. This study shows the information, that is, tables, graphs, and charts concerning the trend in energy efficiency in subways between 1999 and 2001. We suggest a practical application for energy conservation methods and efficient energy use based on the investigations and analyses. (author)

Biological effects of particles from the paris subway system.

Science.gov (United States)

Bachoual, Rafik; Boczkowski, Jorge; Goven, Delphine; Amara, Nadia; Tabet, Lyes; On, Dinhill; Leçon-Malas, Véronique; Aubier, Michel; Lanone, Sophie

2007-10-01

Particulate matter (PM) from atmospheric pollution can easily deposit in the lungs and induce recruitment of inflammatory cells, a source of inflammatory cytokines, oxidants, and matrix metalloproteases (MMPs), which are important players in lung structural homeostasis. In many large cities, the subway system is a potent source of PM emission, but little is known about the biological effects of PM from this source. We performed a comprehensive study to evaluate the biological effects of PM sampled at two sites (RER and Metro) in the Paris subway system. Murine macrophages (RAW 264.7) and C57Bl/6 mice, respectively, were exposed to 0.01-10 microg/cm2 and 5-100 microg/mouse subway PM or reference materials [carbon black (CB), titanium dioxide (TiO2), or diesel exhaust particles (DEPs)]. We analyzed cell viability, production of cellular and lung proinflammatory cytokines [tumor necrosis factor alpha (TNFalpha), macrophage inflammatory protein (MIP-2), KC (the murin analog of interleukin-8), and granulocyte macrophage-colony stimulating factor (GM-CSF)], and mRNA or protein expression of MMP-2, -9, and -12 and heme oxygenase-1 (HO-1). Deferoxamine and polymixin B were used to evaluate the roles of iron and endotoxin, respectively. Noncytotoxic concentrations of subway PM (but not CB, TiO2, or DEPs) induced a time- and dose-dependent increase in TNFalpha and MIP-2 production by RAW 264.7 cells, in a manner involving, at least in part, PM iron content (34% inhibition of TNF production 8 h after stimulation of RAW 264.7 cells with 10 microg/cm2 RER particles pretreated with deferoxamine). Similar increased cytokine production was transiently observed in vivo in mice and was accompanied by an increased neutrophil cellularity of bronchoalveolar lavage (84.83+/-0.98% of polymorphonuclear neutrophils for RER-treated mice after 24 h vs 7.33+/-0.99% for vehicle-treated animals). Subway PM induced an increased expression of MMP-12 and HO-1 both in vitro and in vivo. PM from the

Predicting Short-Term Subway Ridership and Prioritizing Its Influential Factors Using Gradient Boosting Decision Trees

Directory of Open Access Journals (Sweden)

Chuan Ding

2016-10-01

Full Text Available Understanding the relationship between short-term subway ridership and its influential factors is crucial to improving the accuracy of short-term subway ridership prediction. Although there has been a growing body of studies on short-term ridership prediction approaches, limited effort is made to investigate the short-term subway ridership prediction considering bus transfer activities and temporal features. To fill this gap, a relatively recent data mining approach called gradient boosting decision trees (GBDT is applied to short-term subway ridership prediction and used to capture the associations with the independent variables. Taking three subway stations in Beijing as the cases, the short-term subway ridership and alighting passengers from its adjacent bus stops are obtained based on transit smart card data. To optimize the model performance with different combinations of regularization parameters, a series of GBDT models are built with various learning rates and tree complexities by fitting a maximum of trees. The optimal model performance confirms that the gradient boosting approach can incorporate different types of predictors, fit complex nonlinear relationships, and automatically handle the multicollinearity effect with high accuracy. In contrast to other machine learning methods—or “black-box” procedures—the GBDT model can identify and rank the relative influences of bus transfer activities and temporal features on short-term subway ridership. These findings suggest that the GBDT model has considerable advantages in improving short-term subway ridership prediction in a multimodal public transportation system.

Research on the analytical method about influence of gas leakage and explosion on subway

Science.gov (United States)

Ji, Wendong; Yang, Ligong; Chen, Lin

2018-05-01

With the construction and development of city subway, the cross impact of underground rail transit and gas pipe network is becoming more and more serious, but there is no analytical method for the impact of gas explosions on the subway. According to this paper, the gas leakage is equivalent to the TNT explosion equivalent, based on which, the calculation of the explosive impact load is carried out. On the basis of the concrete manifestation of gas explosion, it is more convenient to carry out the subsequent calculation by equivalently treating the explosive impact load as a uniform load within a certain range. The overlying soil of the subway station has played a protective role for the subway, making the displacement of the subway structure in the explosion process significantly reduced. The analysis on the actual case shows that this method can be successfully applied to the quantitative analysis of such accidents.

Gamma-ray dose rate in air on the subway lines in Tokyo metropolitan area

International Nuclear Information System (INIS)

Ogawa, Masayuki; Hosoda, Masahiro; Ogashiwa, Susumu; Fukushi, Masahiro

2008-01-01

Measurements of gamma-ray dose rates in air were performed on 12 subway lines in Tokyo from the perspective of health physics, because the subways are commonly used for commuting in the Tokyo metropolitan area. The results showed that the maximum dose rate (36.5 nGy/h) was 1.6 times higher than that of the minimum one (23.3 nGy/h), and that the dose rate in the subway car was 33% lower than the outside. Also the results strongly suggested that the dose rates depend on the concentration of natural radionuclide around the subway lines and the platform structures rather than the depth. (author)

Geotectonic variations of radon fields in the Tashkent subway stations

International Nuclear Information System (INIS)

Yafasov, A.Ya.; Akimov, V.A.

2001-01-01

The investigations into the radon fields in subsurface service rooms and platforms of the Tashkent subway arranged on the territories with different geotectonic characteristics were conducted by the use of the standard radiometers Alpha-GUARD PQ2000M and Gamma-TRACER (Germany), semiconductor spectrometers RATON (Uzbekistan). The effect of the tectonic factor on the radon fields formation in air of the subway was shown [ru

Origin of inorganic and organic components of PM_2_._5 in subway stations of Barcelona, Spain

International Nuclear Information System (INIS)

Martins, Vânia; Moreno, Teresa; Minguillón, María Cruz; Drooge, Barend L. van; Reche, Cristina; Amato, Fulvio; Miguel, Eladio de; Capdevila, Marta; Centelles, Sonia; Querol, Xavier

2016-01-01

The present work assesses indoor air quality in stations of the Barcelona subway system. PM_2_._5 concentrations on the platforms of 4 subway stations were measured during two different seasons and the chemical composition was determined. A Positive Matrix Factorization analysis was performed to identify and quantify the contributions of major PM_2_._5 sources in the subway stations. Mean PM_2_._5 concentrations varied according to the stations design and seasonal periods. PM_2_._5 was composed of haematite, carbonaceous aerosol, crustal matter, secondary inorganic compounds, trace elements, insoluble sulphate and halite. Organic compounds such as PAHs, nicotine, levoglucosan and aromatic musk compounds were also identified. Subway PM_2_._5 source comprised emissions from rails, wheels, catenaries, brake pads and pantographs. The subway source showed different chemical profiles for each station, but was always dominated by Fe. Control actions on the source are important for the achievement of better air quality in the subway environment. - Highlights: • PM_2_._5 concentrations varied according to stations design and seasonal periods. • Haematite was the most abundant component of PM_2_._5. • Organic compounds such as PAHs were detected in the subway stations. • The subway contribution to ambient PM_2_._5 on the platforms ranged from 9 to 58%. • The chemical profile of the subway emissions varies depending on the station. - Concentrations of PM_2_._5 chemical components varied according to stations design, seasonal periods, and chemical composition of rail, catenary and trains. PM_2_._5 consists mainly of Fe.

The effectiveness of platform screen doors for the prevention of subway suicides in South Korea.

Science.gov (United States)

Chung, Yong Woon; Kang, Sung Jin; Matsubayashi, Tetsuya; Sawada, Yasuyuki; Ueda, Michiko

2016-04-01

Subway suicide can significantly impact the general public. Platform Screen Doors (PSDs) are considered to be an effective strategy to prevent suicides at subway stations, but the evidence on their effectiveness is limited. We assessed the effectiveness of installing half- and full-height platform screen doors in reducing subway suicides using Poisson regression analysis. Ten-year monthly panel data for 121 subway stations between 2003 and 2012 in the Seoul metropolitan area were used for the analysis. We found that installing PSDs decreases fatal suicide cases by 89% (95% CI: 57-97%). We also found that the installation of full-height PSDs resulted in the elimination of subway suicides by completely blocking access to the track area; however, half-height PSDs, which do not extend to the ceiling of the platform, were not as effective as full-height ones. Our findings were based on the data from a single subway operator for a limited period of time. Accordingly, we did not consider the possibility that some passengers choose to die at a station run by other operators. Our study did not examine the potential substitution effects of other suicide methods. Installing physical barriers at subway stations can be an effective strategy to reduce the number of subway suicides; however, half-height PSDs are not as effective as full-height ones, even when they are as high as the height of an adult. Thus, these barriers should be made high enough so that nobody can climb over them. Copyright © 2016 Elsevier B.V. All rights reserved.

Coordination between Subway and Urban Space: A Networked Approach

Directory of Open Access Journals (Sweden)

Lei Mao

2014-05-01

Full Text Available This paper selects Changsha as a case study and constructs the models of the subway network and the urban spatial network by using planning data. In the network models, the districts of Changsha are regarded as nodes and the connections between each pair of districts are regarded as edges. The method is based on quantitative analysis of the node weights and the edge weights, which are defined in the complex network theory. And the structures of subway and urban space are visualized in the form of networks. Then, through analyzing the discrepancy coefficients of the corresponding nodes and edges, the paper carries out a comparison between the two networks to evaluate the coordination. The results indicate that only 21.4% of districts and 13.2% of district connections have a rational coordination. Finally, the strategies are put forward for optimization, which suggest adjusting subway transit density, regulating land-use intensity and planning new mass transits for the uncoordinated parts.

Improved social force model based on exit selection for microscopic pedestrian simulation in subway station

Institute of Scientific and Technical Information of China (English)

郑勋; 李海鹰; 孟令云; 许心越; 陈旭

2015-01-01

An improved social force model based on exit selection is proposed to simulate pedestrians’ microscopic behaviors in subway station. The modification lies in considering three factors of spatial distance, occupant density and exit width. In addition, the problem of pedestrians selecting exit frequently is solved as follows: not changing to other exits in the affected area of one exit, using the probability of remaining preceding exit and invoking function of exit selection after several simulation steps. Pedestrians in subway station have some special characteristics, such as explicit destinations, different familiarities with subway station. Finally, Beijing Zoo Subway Station is taken as an example and the feasibility of the model results is verified through the comparison of the actual data and simulation data. The simulation results show that the improved model can depict the microscopic behaviors of pedestrians in subway station.

Predicting PM10 concentration in Seoul metropolitan subway stations using artificial neural network (ANN).

Science.gov (United States)

Park, Sechan; Kim, Minjeong; Kim, Minhae; Namgung, Hyeong-Gyu; Kim, Ki-Tae; Cho, Kyung Hwa; Kwon, Soon-Bark

2018-01-05

The indoor air quality of subway systems can significantly affect the health of passengers since these systems are widely used for short-distance transit in metropolitan urban areas in many countries. The particles generated by abrasion during subway operations and the vehicle-emitted pollutants flowing in from the street in particular affect the air quality in underground subway stations. Thus the continuous monitoring of particulate matter (PM) in underground station is important to evaluate the exposure level of PM to passengers. However, it is difficult to obtain indoor PM data because the measurement systems are expensive and difficult to install and operate for significant periods of time in spaces crowded with people. In this study, we predicted the indoor PM concentration using the information of outdoor PM, the number of subway trains running, and information on ventilation operation by the artificial neural network (ANN) model. As well, we investigated the relationship between ANN's performance and the depth of underground subway station. ANN model showed a high correlation between the predicted and actual measured values and it was able to predict 67∼80% of PM at 6 subway station. In addition, we found that platform shape and depth influenced the model performance. Copyright © 2017 Elsevier B.V. All rights reserved.

Study on energy saving of subway station based on orthogonal experimental method

Science.gov (United States)

Guo, Lei

2017-05-01

With the characteristics of quick, efficient and large amount transport, the subway has become an important way to solve urban traffic congestion. As the subway environment will follow the change of external environment factors such as temperature and load of personnel changes, three-dimensional numerical simulations study is conducted by using CFD software for air distribution of subway platform. The influence of different loads (the supply air temperature and velocity of air condition, personnel load, heat flux of the wall) on the subway platform flow field are also analysed. The orthogonal experiment method is applied to the numerical simulation analysis for human comfort under different parameters. Based on those results, the functional relationship between human comfort and the boundary conditions of the platform is produced by multiple linear regression fitting method, the order of major boundary conditions which affect human comfort is obtained. The above study provides a theoretical basis for the final energy-saving strategies.

Black carbon and particulate matter (PM2.5) concentrations in New York City's subway stations.

Science.gov (United States)

Vilcassim, M J Ruzmyn; Thurston, George D; Peltier, Richard E; Gordon, Terry

2014-12-16

The New York City (NYC) subway is the main mode of transport for over 5 million passengers on an average weekday. Therefore, airborne pollutants in the subway stations could have a significant impact on commuters and subway workers. This study looked at black carbon (BC) and particulate matter (PM2.5) concentrations in selected subway stations in Manhattan. BC and PM2.5 levels were measured in real time using a Micro-Aethalometer and a PDR-1500 DataRAM, respectively. Simultaneous samples were also collected on quartz filters for organic and elemental carbon (OC/EC) analysis and on Teflon filters for gravimetric and trace element analysis. In the underground subway stations, mean real time BC concentrations ranged from 5 to 23 μg/m(3), with 1 min average peaks >100 μg/m(3), while real time PM2.5 levels ranged from 35 to 200 μg/m(3). Mean EC levels ranged from 9 to 12.5 μg/m(3). At street level on the same days, the mean BC and PM2.5 concentrations were below 3 and 10 μg/m(3), respectively. This study shows that both BC soot and PM levels in NYC's subways are considerably higher than ambient urban street levels and that further monitoring and investigation of BC and PM subway exposures are warranted.

Spatial distribution of particulate matter (PM10 and PM2.5) in Seoul Metropolitan Subway stations.

Science.gov (United States)

Kim, Ki Youn; Kim, Yoon Shin; Roh, Young Man; Lee, Cheol Min; Kim, Chi Nyon

2008-06-15

The aims of this study are to examine the concentrations of PM10 and PM2.5 in areas within the Seoul Metropolitan Subway network and to provide fundamental data in order to protect respiratory health of subway workers and passengers from air pollutants. A total of 22 subway stations located on lines 1-4 were selected based on subway official's guidance. At these stations both subway worker areas (station offices, rest areas, ticket offices and driver compartments) and passengers areas (station precincts, subway carriages and platforms) were the sites used for measuring the levels of PM. The mean concentrations of PM10 and PM2.5 were relatively higher on platforms, inside subway carriages and in driver compartments than in the other areas monitored. The levels of PM10 and PM2.5 for station precincts and platforms exceeded the 24-h acceptable threshold limits of 150 microg/m3 for PM10 and 35 microg/m3 for PM2.5, which are regulated by the U.S. Environmental Protection Agency (EPA). However, levels measured in station and ticket offices fell below the respective threshold. The mean PM10 and PM2.5 concentrations on platforms located underground were significantly higher than those at ground level (p<0.05).

The Usefulness of Tactual Maps of the New York City Subway System.

Science.gov (United States)

Luxton, K.; And Others

1994-01-01

Sixteen people with blindness or visual impairments used three different types of tactual maps of the New York City subway system presenting information at three levels of specificity. Results indicated that the tactual maps improved participants' attitudes toward the subway and benefited blind as well as low vision participants. (Author/DB)

Air pollution and activity during transportation by car, subway, and walking.

Science.gov (United States)

Morabia, Alfredo; Amstislavski, Philippe N; Mirer, Franklin E; Amstislavski, Tashia M; Eisl, Holger; Wolff, Mary S; Markowitz, Steven B

2009-07-01

Little evidence exists about the health risks and benefits associated with using public buses and subways rather than cars. The objective of the current study was to assess the magnitude and variance of personal exposure to particulate matter 2.5 microns or smaller (PM(2.5)) and concomitant physical activity energy expenditure (PAEE) for transportation by car, subway, or walking. Twenty nonsmoking volunteers from New York City traveled on predetermined routes by car, subway, and walking, for up to 8 hours on 3 different days, between October 2007 and February 2008. Outfitted with a personal monitor with PM(2.5) aerosol inlet, and a GPS receiver, they completed a detailed physical activity diary for each route. Both metabolic equivalent (MET) and PAEE rates (Kcal/min) were computed from GPS-derived activity durations and speeds, activity-specific METs, and measured body weight. Total PM(2.5) exposures did not differ among car, subway, and walking arms (respectively, 21.4, 30.6, and 26.5 microg/m(3) x min, p=0.19); but average MET values (respectively, 1.51, 2.03, and 2.60 Kcal/kg x hr, ptransportation.

Origin of inorganic and organic components of PM2.5 in subway stations of Barcelona, Spain.

Science.gov (United States)

Martins, Vânia; Moreno, Teresa; Minguillón, María Cruz; van Drooge, Barend L; Reche, Cristina; Amato, Fulvio; de Miguel, Eladio; Capdevila, Marta; Centelles, Sonia; Querol, Xavier

2016-01-01

The present work assesses indoor air quality in stations of the Barcelona subway system. PM2.5 concentrations on the platforms of 4 subway stations were measured during two different seasons and the chemical composition was determined. A Positive Matrix Factorization analysis was performed to identify and quantify the contributions of major PM2.5 sources in the subway stations. Mean PM2.5 concentrations varied according to the stations design and seasonal periods. PM2.5 was composed of haematite, carbonaceous aerosol, crustal matter, secondary inorganic compounds, trace elements, insoluble sulphate and halite. Organic compounds such as PAHs, nicotine, levoglucosan and aromatic musk compounds were also identified. Subway PM2.5 source comprised emissions from rails, wheels, catenaries, brake pads and pantographs. The subway source showed different chemical profiles for each station, but was always dominated by Fe. Control actions on the source are important for the achievement of better air quality in the subway environment. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Predictors of suicide and suicide attempt in subway stations: a population-based ecological study.

Science.gov (United States)

Niederkrotenthaler, Thomas; Sonneck, Gernot; Dervic, Kanita; Nader, Ingo W; Voracek, Martin; Kapusta, Nestor D; Etzersdorfer, Elmar; Mittendorfer-Rutz, Ellenor; Dorner, Thomas

2012-04-01

Suicidal behavior on the subway often involves young people and has a considerable impact on public life, but little is known about factors associated with suicides and suicide attempts in specific subway stations. Between 1979 and 2009, 185 suicides and 107 suicide attempts occurred on the subway in Vienna, Austria. Station-specific suicide and suicide attempt rates (defined as the frequency of suicidal incidents per time period) were modeled as the outcome variables in bivariate and multivariate Poisson regression models. Structural station characteristics (presence of a surveillance unit, train types used, and construction on street level versus other construction), contextual station characteristics (neighborhood to historical sites, size of the catchment area, and in operation during time period of extensive media reporting on subway suicides), and passenger-based characteristics (number of passengers getting on the trains per day, use as meeting point by drug users, and socioeconomic status of the population in the catchment area) were used as the explanatory variables. In the multivariate analyses, subway suicides increased when stations were served by the faster train type. Subway suicide attempts increased with the daily number of passengers getting on the trains and with the stations' use as meeting points by drug users. The findings indicate that there are some differences between subway suicides and suicide attempts. Completed suicides seem to vary most with train type used. Suicide attempts seem to depend mostly on passenger-based characteristics, specifically on the station's crowdedness and on its use as meeting point by drug users. Suicide-preventive interventions should concentrate on crowded stations and on stations frequented by risk groups.

Black Carbon and Particulate Matter (PM2.5) Concentrations in New York City’s Subway Stations

Science.gov (United States)

2015-01-01

The New York City (NYC) subway is the main mode of transport for over 5 million passengers on an average weekday. Therefore, airborne pollutants in the subway stations could have a significant impact on commuters and subway workers. This study looked at black carbon (BC) and particulate matter (PM2.5) concentrations in selected subway stations in Manhattan. BC and PM2.5 levels were measured in real time using a Micro-Aethalometer and a PDR-1500 DataRAM, respectively. Simultaneous samples were also collected on quartz filters for organic and elemental carbon (OC/EC) analysis and on Teflon filters for gravimetric and trace element analysis. In the underground subway stations, mean real time BC concentrations ranged from 5 to 23 μg/m3, with 1 min average peaks >100 μg/m3, while real time PM2.5 levels ranged from 35 to 200 μg/m3. Mean EC levels ranged from 9 to 12.5 μg/m3. At street level on the same days, the mean BC and PM2.5 concentrations were below 3 and 10 μg/m3, respectively. This study shows that both BC soot and PM levels in NYC’s subways are considerably higher than ambient urban street levels and that further monitoring and investigation of BC and PM subway exposures are warranted. PMID:25409007

Prevalence of Trichomonas vaginalis in Women Visiting 2 Obstetrics and Gynecology Clinics in Daegu, South Korea.

Science.gov (United States)

Goo, Youn-Kyoung; Shin, Won-Sik; Yang, Hye-Won; Joo, So-Young; Song, Su-Min; Ryu, Jae-Sook; Lee, Won-Myung; Kong, Hyun-Hee; Lee, Won-Ki; Lee, Sang-Eun; Lee, Won-Ja; Chung, Dong-Il; Hong, Yeonchul

2016-02-01

This study explored epidemiological trends in trichomoniasis in Daegu, South Korea. Wet mount microscopy, PCR, and multiplex PCR were used to test for Trichomonas vaginalis in vaginal swab samples obtained from 621 women visiting 2 clinics in Daegu. Of the 621 women tested, microscopy detected T. vaginalis in 4 (0.6%) patients, PCR detected T. vaginalis in 19 (3.0%) patients, and multiplex PCR detected T. vaginalis in 12 (1.9%) patients. Testing via PCR demonstrated high sensitivity and high negative predictive value for T. vaginalis. Among the 19 women who tested positive for T. vaginalis according to PCR, 94.7% (18/19) reported vaginal signs and symptoms. Notably, more than 50% of T. vaginalis infections occurred in females younger than 30 years old, and 58% were unmarried. Multiplex PCR, which simultaneously detects pathogens from various sexually transmitted infections, revealed that 91.7% (11/12) of patients were infected with 2 or more pathogens. Mycoplasma hominis was the most prevalent co-infection pathogen with T. vaginalis, followed by Ureaplasma urealyticum and Chlamydia trachomatis. Our results indicate that PCR and multiplex PCR are the most sensitive tools for T. vaginalis diagnosis, rather than microscopy which has been routinely used to detect T. vaginalis infections in South Korea. Therefore, clinicians should take note of the high prevalence of T. vaginalis infections among adolescent and young women in order to prevent persistent infection and transmission of this disease.

Determination of future prevention strategies in elite track and field: analysis of Daegu 2011 IAAF Championships injuries and illnesses surveillance

OpenAIRE

Alonso, Juan-Manuel; Edouard, Pascal; Fischetto, Giuseppe; Adams, Bob; Depiesse, Frédéric; Mountjoy, Margo

2012-01-01

Objective To determine the incidence and characteristics of newly incurred injuries and illnesses during international Athletics Championships, by improving the medical surveillance coverage, in order to determine future prevention strategies. Design Prospective recording of newly occurred injuries and illnesses. Setting 13th International Association of Athletics Federations World Championships in Athletics 2011 in Daegu, Korea. Participants National team and Local Organising Committee physi...

Public Health Lessons Learned From Analysis of New York City Subway Injuries

Science.gov (United States)

Guth, Amber A.; O’Neill, Andrea; Pachter, H. Leon; Diflo, Thomas

2006-01-01

Serious subway injuries are devastating to their young victims and have high rates of mortality and amputation. We identified the urban population at greatest risk for subway injuries and investigated the influence of local economies on injury rates. We propose using changes in social conditions as a “trigger” for increased vigilance and protective measures at times of higher risk. PMID:16449596

Comfort parameters - Ventilation of a subway wagon

Science.gov (United States)

Petr, Pavlíček; Ladislav, Tříska

2017-09-01

Research and development of a ventilation system is being carried out as a part of project TA04030774 of the Technology Agency of the Czech Republic. Name of the project is "Research and Development of Mass-optimized Components for Rail Vehicles". Problems being solved are development and testing of a new concept for ventilation systems for public transport vehicles. The main improvements should be a reduction of the mass of the whole system, easy installation and reduction of the noise of the ventilation system. This article is focused on the comfort parameters in a subway wagon (measurement and evaluation carried out on a function sample in accordance with the regulations). The input to the project is a ventilator hybrid casing for a subway wagon, which was manufactured and tested during the Ministry of Industry and Trade project TIP FR-TI3/449.

Health effects of a subway environment in mild asthmatic volunteers.

Science.gov (United States)

Klepczyńska-Nyström, Anna; Larsson, Britt-Marie; Grunewald, Johan; Pousette, Charlotte; Lundin, Anders; Eklund, Anders; Svartengren, Magnus

2012-01-01

Particle exposure is known to have negative health effects. In Stockholm the environment in the subway has been reported to have higher particle exposure levels, measured as PM(2.5) and PM(10), than roads with intense traffic in the inner city area. We have recently shown that healthy volunteers exposed to subway environment had statistically significant increase of fibrinogen and CD4 cells expressing regulatory T-cell marker CD25(bright)/FOXP3 in blood. The aim of the present study was to find out whether a more vulnerable population, asthmatics, would demonstrate similar or other changes in the lungs or in the peripheral blood. Sixteen mild asthmatics were exposed to a subway and a control environment for 2 h while being monitored by measurements of lung function, and inflammatory response in the lower airways evaluated by bronchoscopy and in peripheral blood. An attempt to standardize the exposures was done, by letting the volunteers alternate 15 min intervals of moderate exercise on a bicycle ergometer with 15 min of rest. We found a statistically significant increased frequency of CD4 cells expressing T-cell activation marker CD25 in bronchoalveolar lavage fluid, but no significant increase of regulatory T-cells in blood as was found in healthy volunteers. Our study shows that airway inflammatory responses after exposure in subway environment differ between asthmatic and healthy humans. Copyright © 2011 Elsevier Ltd. All rights reserved.

Numerical Simulations for a Typical Train Fire in China

Directory of Open Access Journals (Sweden)

W. K. Chow

2011-01-01

Full Text Available Railway is the key transport means in China including the Mainland, Taiwan, and Hong Kong. Consequent to so many big arson and accidental fires in the public transport systems including trains and buses, fire safety in passenger trains is a concern. Numerical simulations with Computational Fluid Dynamics on identified fire scenarios with typical train compartments in China will be reported in this paper. The heat release rate of the first ignited item was taken as the input parameter. The mass lost rate of fuel vapor of other combustibles was estimated to predict the resultant heat release rates by the combustion models in the software. Results on air flow, velocity vectors, temperature distribution, smoke layer height, and smoke spread patterns inside the train compartment were analyzed. The results are useful for working out appropriate fire safety measures for train vehicles and determining the design fire for subway stations and railway tunnels.

Subway-Related Trauma: An Urban Public Health Issue with a High Case-Fatality Rate.

Science.gov (United States)

Rodier, Simon G; DiMaggio, Charles J; Wall, Stephen; Sim, Vasiliy; Frangos, Spiros G; Ayoung-Chee, Patricia; Bukur, Marko; Tandon, Manish; Todd, S Rob; Marshall, Gary T

2018-05-09

Between 1990 and 2003, there were 668 subway-related fatalities in New York City. However, subway-related trauma remains an understudied area of injury-related morbidity and mortality. The objective of this study was to characterize the injuries and events leading up to the injuries of all patients admitted after subway-related trauma. We conducted a retrospective case series of subway-related trauma at a Level I trauma center from 2001 to 2016. Descriptive epidemiology of patient demographics, incident details, injuries, and outcomes were analyzed. Over 15 years, 254 patients were admitted for subway-related trauma. The mean (standard error of the mean) age was 41 (1.0) years, 80% were male (95% confidence interval [CI] 74-84%) and median Injury Severity Score was 14 (interquartile range [IQR] 5-24). The overall case-fatality rate was 10% (95% CI 7-15%). The most common injuries were long-bone fractures, intracranial hemorrhage, and traumatic amputations. Median length of stay was 6 days (IQR 1-18 days). Thirty-seven percent of patients required surgical intervention. At the time of injury, 55% of patients (95% CI 49-61%) had a positive urine drug or alcohol screen, 16% (95% CI 12-21%) were attempting suicide, and 39% (95% CI 33-45%) had a history of psychiatric illness. Subway-related trauma is associated with a high case-fatality rate. Alcohol or drug intoxication and psychiatric illness can increase the risk of this type of injury. Copyright © 2018 Elsevier Inc. All rights reserved.

The role of subway travel in an influenza epidemic: a New York City simulation.

Science.gov (United States)

Cooley, Philip; Brown, Shawn; Cajka, James; Chasteen, Bernadette; Ganapathi, Laxminarayana; Grefenstette, John; Hollingsworth, Craig R; Lee, Bruce Y; Levine, Burton; Wheaton, William D; Wagener, Diane K

2011-10-01

The interactions of people using public transportation in large metropolitan areas may help spread an influenza epidemic. An agent-based model computer simulation of New York City's (NYC's) five boroughs was developed that incorporated subway ridership into a Susceptible-Exposed-Infected-Recovered disease model framework. The model contains a total of 7,847,465 virtual people. Each person resides in one of the five boroughs of NYC and has a set of socio-demographic characteristics and daily behaviors that include age, sex, employment status, income, occupation, and household location and membership. The model simulates the interactions of subway riders with their workplaces, schools, households, and community activities. It was calibrated using historical data from the 1957-1958 influenza pandemics and from NYC travel surveys. The surveys were necessary to enable inclusion of subway riders into the model. The model results estimate that if influenza did occur in NYC with the characteristics of the 1957-1958 pandemic, 4% of transmissions would occur on the subway. This suggests that interventions targeted at subway riders would be relatively ineffective in containing the epidemic. A number of hypothetical examples demonstrate this feature. This information could prove useful to public health officials planning responses to epidemics.

Airborne particulate metals in the New York City subway: a pilot study to assess the potential for health impacts.

Science.gov (United States)

Grass, David S; Ross, James M; Family, Farnosh; Barbour, Jonathan; James Simpson, H; Coulibaly, Drissa; Hernandez, Jennifer; Chen, Yingdi; Slavkovich, Vesna; Li, Yongliang; Graziano, Joseph; Santella, Regina M; Brandt-Rauf, Paul; Chillrud, Steven N

2010-01-01

A prior study in New York City observed that airborne concentrations of three metals found in steel - iron, manganese, and chromium - are more than 100 times higher in the subway system than in aboveground air. To investigate the potential for health effects of exposure at these levels, we conducted a pilot study of subway workers comparing personal exposures to steel dust with biomarkers of metal exposure, oxidative stress, and DNA damage in blood and urine samples. Workers wore a personal air sampler operating at 4L/m for one to three work shifts with blood and urine samples collected at the end of the final shift. We found that PM(2.5) exposures varied among subway workers on the basis of job title and job activity. The subway workers' mean time-weighted PM(2.5) exposure was 52 microg/m3, with a median of 27 microg/m3, and a range of 6-469 microg/m3. The observed concentrations of PM(2.5), iron, manganese, and chromium fell well below occupational standards. Biomarker concentrations among the 39 subway workers were compared with a group of 11 bus drivers, and a group of 25 suburban office workers. Concentrations of DNA-protein crosslinks and chromium in plasma were significantly higher in subway workers than in bus drivers, but no significant difference was observed for these biomarkers between subway workers and office workers. Urinary isoprostane concentrations were significantly correlated with the number of years working in the subway system, and were detected at higher, though not significantly higher, concentrations in subway workers than in bus drivers or office workers. At the group level, there was no consistent pattern of biomarker concentrations among subway workers significantly exceeding those of the bus drivers and office workers. At the individual level, steel dust exposure was not correlated with any of the biomarkers measured.

Assessment of noise exposure during commuting in the Madrid subway.

Science.gov (United States)

Tabacchi, M; Pavón, I; Ausejo, M; Asensio, C; Recuero, M

2011-09-01

Because noise-induced hearing impairment is the result not only of occupational noise exposure but also of total daily noise exposure, it is important to take the non-occupational exposure of individuals (during commuting to and from their jobs, at home, and during recreational activities) into account. Mass transit is one of the main contributors to non-occupational noise exposure. We developed a new methodology to estimate a representative commuting noise exposure. The methodology was put into practice for the Madrid subway because of all Spanish subway systems it covers the highest percentage of worker journeys (22.6%). The results of the application highlight that, for Madrid subway passengers, noise exposure level normalized to a nominal 8 hr (L(Ex,8h-cj) ) depends strongly on the type of train, the presence of squealing noise, and the public address audio system, ranging from 68.6 dBA to 72.8 dBA. These values play an important role in a more complete evaluation of a relationship between noise dose and worker health response.

Concentrations, properties, and health risk of PM2.5 in the Tianjin City subway system.

Science.gov (United States)

Wang, Bao-Qing; Liu, Jian-Feng; Ren, Zi-Hui; Chen, Rong-Hui

2016-11-01

A campaign was conducted to assess and compare the personal exposure in L3 of Tianjin subway, focusing on PM 2.5 levels, chemical compositions, morphology analysis, as well as the health risk of heavy metal in PM 2.5 . The results indicated that the average concentration of the PM 2.5 was 151.43 μg/m 3 inside the train of the subway during rush hours. PM 2.5 concentrations inside car under the ground are higher than those on the ground, and PM 2.5 concentrations on the platform are higher than those inside car. Regarding metal concentrations, the highest element in PM 2.5 samples was Fe; the level of which is 17.55 μg/m 3 . OC is a major component of PM 2.5 in Tianjin subway. Secondary organic carbon is the formation of gaseous organic pollutants in subway. SEM-EDX and TEM-EDX exhibit the presence of individual particle with a large metal content in the subway samples. For small Fe metal particles, iron oxide can be formed easily. With regard to their sources, Fe-containing particles are generated mainly from mechanical wear and friction processes at the rail-wheel-brake interfaces. The non-carcinogenic risk to metals Cr, Ni, Cu, Zn and Pb, and carcinogenic hazard of Cr and Ni were all below the acceptable level in L3 of Tianjin subway.

Chemical compositions of subway particles in Seoul, Korea determined by a quantitative single particle analysis.

Science.gov (United States)

Kang, Sunni; Hwang, HeeJin; Park, YooMyung; Kim, HyeKyoung; Ro, Chul-Un

2008-12-15

A novel single particle analytical technique, low-Z particle electron probe X-ray microanalysis, was applied to characterize seasonal subway samples collected at a subway station in Seoul, Korea. For all 8 samples collected twice in each season, 4 major types of subway particles, based on their chemical compositions, are significantly encountered: Fe-containing; soil-derived; carbonaceous; and secondary nitrate and/or sulfate particles. Fe-containing particles are generated indoors from wear processes at rail-wheel-brake interfaces while the others may be introduced mostly from the outdoor urban atmosphere. Fe-containing particles are the most frequently encountered with relative abundances in the range of 61-79%. In this study, it is shown that Fe-containing subway particles almost always exist either as partially or fully oxidized forms in underground subway microenvironments. Their relative abundances of Fe-containing particles increase as particle sizes decrease. Relative abundances of Fe-containing particles are higher in morning samples than in afternoon samples because of heavier train traffic in the morning. In the summertime samples, Fe-containing particles are the most abundantly encountered, whereas soil-derived and nitrate/sulfate particles are the least encountered, indicating the air-exchange between indoor and outdoor environments is limited in the summer, owing to the air-conditioning in the subway system. In our work, it was observed that the relative abundances of the particles of outdoor origin vary somewhat among seasonal samples to a lesser degree, reflecting that indoor emission sources predominate.

Subway particles are more genotoxic than street particles and induce oxidative stress in cultured human lung cells.

Science.gov (United States)

Karlsson, Hanna L; Nilsson, Lennart; Möller, Lennart

2005-01-01

Epidemiological studies have shown an association between airborne particles and a wide range of adverse health effects. The mechanisms behind these effects include oxidative stress and inflammation. Even though traffic gives rise to high levels of particles in the urban air, people are exposed to even higher levels in the subway. However, there is a lack of knowledge regarding how particles from different urban subenvironments differ in toxicity. The main aim of the present study was to compare the ability of particles from a subway station and a nearby very busy urban street, respectively, to damage DNA and to induce oxidative stress. Cultured human lung cells (A549) were exposed to particles, DNA damage was analyzed using single cell gel electrophoresis (the comet assay), and the ability to induce oxidative stress was measured as 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) formation in lung cell DNA. We found that the subway particles were approximately eight times more genotoxic and four times more likely to cause oxidative stress in the lung cells. When the particles, water extracts from the particles, or particles treated with the metal chelator deferoxamine mesylate were incubated with 2'-deoxyguanosine (dG) and 8-oxodG was analyzed, we found that the oxidative capacity of the subway particles was due to redox active solid metals. Furthermore, analysis of the atomic composition showed that the subway particles to a dominating degree (atomic %) consisted of iron, mainly in the form of magnetite (Fe3O4). By using electron microscopy, the interaction between the particles and the lung cells was shown. The in vitro reactivity of the subway particles in combination with the high particle levels in subway systems give cause of concern due to the high number of people that are exposed to subway particles on a daily basis. To what extent the subway particles cause health effects in humans needs to be further evaluated.

Subway train-related fatalities in New York City: accident versus suicide.

Science.gov (United States)

Lin, Peter T; Gill, James R

2009-11-01

We examined the characteristics of subway train-related fatalities in New York City between Jan. 1, 2003 and May 31, 2007 in order to determine which factors are useful in differentiating accident from suicide. Subway train-related deaths with homicide and undetermined manners also are included. During this period, there were 211 subway train-related fatalities. The manners of death were: suicide (n = 111), accident (n = 76), undetermined (n = 20), and homicide (n = 4). The causes of death were blunt trauma (n = 206) and electrocution (n = 5). Torso transection and extremity amputation were more frequent in suicides. Antidepressant medications were more frequently detected in suicides, whereas cocaine and ethanol were more frequent in accidents. However, autopsy findings should be weighed in the context of the entire evaluation along with other circumstantial and investigative findings. In unwitnessed deaths where additional information is unavailable or discrepant, the most appropriate manner of death usually is undetermined.

The performance and economical analysis of grid-connected photovoltaic systems in Daegu, Korea

International Nuclear Information System (INIS)

Kim, Ju-Young; Jeon, Gyu-Yeob; Hong, Won-Hwa

2009-01-01

The distribution of the photovoltaic systems is faced with technological and economic problems, and the businesses and corporations feel burdened by the photovoltaic system's dubious economic value and high construction costs. Thus, not too many enterprises or private citizens have been participating in the business of installing photovoltaic systems. Moreover, because of lack of skills in integrating engineering and architectural design, they are experiencing difficulties even in using the technologies that have already been developed and available for application. To provide the basic information and specific data required for making the guidelines for developing photovoltaic technologies, this paper evaluates the system types, the actual state of operation, and performance of the two photovoltaic systems that are installed in Kiemyung University's Osan Building and Dongho Elementary School in Daegu Metropolitan City

[To the issue on the optimization and regulation of microclimate in the subway trains and stations].

Science.gov (United States)

Leksin, A G; Beresneva, T G; Kaptsov, V A; Korotich, L P; Evlampieva, M N; Timoshenkova, E V

2014-01-01

There is presented an overview of currently existing regulatory framework governing the parameters of the microclimate in the salons of subway passenger cars and stations. Analysis of the normative documents indicated that they contain very incomplete, contradictory, often unfounded information about the parameters of microclimate parameters in salons of subway rolling stock. Also, there are no clear cut hygienically-sound requirements for the work of imposed on the rolling stock subway systems provide microclimate, including new systems for air conditioning and disinfection.

Managing Recurrent Congestion of Subway Network in Peak Hours with Station Inflow Control

Directory of Open Access Journals (Sweden)

Qingru Zou

2018-01-01

Full Text Available Station inflow control (SIC is an important and effective method for reducing recurrent congestion during peak hours in the Beijing, Shanghai, and Guangzhou subway systems. This work proposes a practical and efficient method for establishing a static SIC scheme in normal weekdays for large-scale subway networks. First, a traffic assignment model without capacity constraint is utilized to determine passenger flow distributions on the network. An internal relationship between station inflows and section flows is then constructed. Second, capacity bottlenecks are identified by considering the transport capacity of each section. Then, a feedback-based bottleneck elimination strategy is established to search target control stations and determine their control time and control strength. To validate the effectiveness of the proposed approach, a decision support system coded in the C# programming language was developed, and the Beijing subway was used as a case study. The results indicate that the proposed method and tool are capable of practical applications, and the generated SIC plan has better performance over the existing SIC plan. This study provides a practical and useful method for operation agencies to construct SIC schemes in the subway system.

Estimation of inhaled airborne particle number concentration by subway users in Seoul, Korea

International Nuclear Information System (INIS)

Kim, Minhae; Park, Sechan; Namgung, Hyeong-Gyu; Kwon, Soon-Bark

2017-01-01

Exposure to airborne particulate matter (PM) causes several diseases in the human body. The smaller particles, which have relatively large surface areas, are actually more harmful to the human body since they can penetrate deeper parts of the lungs or become secondary pollutants by bonding with other atmospheric pollutants, such as nitrogen oxides. The purpose of this study is to present the number of PM inhaled by subway users as a possible reference material for any analysis of the hazards to the human body arising from the inhalation of such PM. Two transfer stations in Seoul, Korea, which have the greatest number of users, were selected for this study. For 0.3–0.422 μm PM, particle number concentration (PNC) was highest outdoors but decreased as the tester moved deeper underground. On the other hand, the PNC between 1 and 10 μm increased as the tester moved deeper underground and showed a high number concentration inside the subway train as well. An analysis of the particles to which subway users are actually exposed to (inhaled particle number), using particle concentration at each measurement location, the average inhalation rate of an adult, and the average stay time at each location, all showed that particles sized 0.01–0.422 μm are mostly inhaled from the outdoor air whereas particles sized 1–10 μm are inhaled as the passengers move deeper underground. Based on these findings, we expect that the inhaled particle number of subway users can be used as reference data for an evaluation of the hazards to health caused by PM inhalation. - Highlights: • Size-dependent aerosol number was measured along the path of subway user. • Particles less than 0.4 μm were inhaled in outdoor but less so as deeper underground. • Coarse particles were inhaled significantly as users moved deeper underground. - We estimated the inhaled aerosol number concentration depending on particle size along the path of subway users.

Exposure level and distribution characteristics of airborne bacteria and fungi in Seoul metropolitan subway stations.

Science.gov (United States)

Kim, Ki Youn; Kim, Yoon Shin; Kim, Daekeun; Kim, Hyeon Tae

2011-01-01

The exposure level and distribution characteristics of airborne bacteria and fungi were assessed in the workers' activity areas (station office, bedroom, ticket office and driver's seat) and passengers' activity areas (station precinct, inside the passenger carriage, and platform) of the Seoul metropolitan subway. Among investigated areas, the levels of airborne bacteria and fungi in the workers' bedroom and station precincts were relatively high. No significant difference was found in the concentration of airborne bacteria and fungi between the underground and above ground activity areas of the subway. The genera identified in all subway activity areas with a 5% or greater detection rate were Staphylococcus, Micrococcus, Bacillus and Corynebacterium for airborne bacteria and Penicillium, Cladosporium, Chrysosporium, Aspergillus for airborne fungi. Staphylococcus and Micrococcus comprised over 50% of the total airborne bacteria and Penicillium and Cladosporium comprised over 60% of the total airborne fungi, thus these four genera are the predominant genera in the subway station.

Iron speciation of airborne subway particles by the combined use of energy dispersive electron probe X-ray microanalysis and Raman microspectrometry.

Science.gov (United States)

Eom, Hyo-Jin; Jung, Hae-Jin; Sobanska, Sophie; Chung, Sang-Gwi; Son, Youn-Suk; Kim, Jo-Chun; Sunwoo, Young; Ro, Chul-Un

2013-11-05

Quantitative energy-dispersive electron probe X-ray microanalysis (ED-EPMA), known as low-Z particle EPMA, and Raman microspectrometry (RMS) were applied in combination for an analysis of the iron species in airborne PM10 particles collected in underground subway tunnels. Iron species have been reported to be a major chemical species in underground subway particles generated mainly from mechanical wear and friction processes. In particular, iron-containing particles in subway tunnels are expected to be generated with minimal outdoor influence on the particle composition. Because iron-containing particles have different toxicity and magnetic properties depending on their oxidation states, it is important to determine the iron species of underground subway particles in the context of both indoor public health and control measures. A recently developed analytical methodology, i.e., the combined use of low-Z particle EPMA and RMS, was used to identify the chemical species of the same individual subway particles on a single particle basis, and the bulk iron compositions of airborne subway particles were also analyzed by X-ray diffraction. The majority of airborne subway particles collected in the underground tunnels were found to be magnetite, hematite, and iron metal. All the particles collected in the tunnels of underground subway stations were attracted to permanent magnets due mainly to the almost ubiquitous ferrimagnetic magnetite, indicating that airborne subway particles can be removed using magnets as a control measure.

The association between psychiatric disorders and work-related problems among subway drivers in Korea.

Science.gov (United States)

Kim, Se-Eun; Kim, Hyoung-Ryoul; Park, Jong-Ik; Lee, Hae Woo; Lee, Jongin; Byun, Junsu; Yim, Hyeon Woo

2014-01-01

This study aimed to find the prevalence and occupational risk factors for major psychiatric disorders among subway drivers in South Korea. Of all 998 current subway drivers, 995 participated in this study. The Korean version of the Composite International Diagnostic Interview (K-CIDI 2.1) was administered by trained interviewers to diagnose psychiatric disorders in all participants. The questions on socio-demographic characteristics and working conditions included some questions related to a person under train (PUT) experience and work-related problems. One-year prevalence and lifetime prevalence of major depressive disorder (MDD), post-traumatic stress disorder (PTSD), and panic disorder were diagnosed through the interview. The standardized prevalence ratios (SPRs) of these three disorders were calculated in the sample of subway drivers using the 2011 Korean National Epidemiologic Survey data as a basis. Multiple logistic regressions were performed to determine the association between work-related factors and the prevalence of the psychiatric disorders. The standardized prevalence ratios (SPRs) for a 1-year prevalence of MDD and PTSD among subway drivers were 1.1 (95% CI 0.7-1.7) and 5.6 (95% CI 3.1-8.8), respectively. Conflict with passengers was significantly associated with an increased risk for both MDD and PTSD in 1-year and in lifetime prevalence. Experiencing a sudden stop due to an emergency bell increased the risk of the lifetime prevalence of MDD (OR 2.61, 95% CI 1.14-6.97) and PTSD (OR 7.53, 95% CI 1.77-32.02). The risk of PTSD significantly increased among drivers who once experienced a near accident in terms of both the 1-year prevalence (OR 8.81, 95% CI 1.96-39.3) and the lifetime prevalence (OR 6.36, 95% CI 2.40-16.90). PTSD and panic disorder were more prevalent among subway drivers than in the general population. We found that having a conflict with passengers, a near accident, and a breakdown while driving can be risk factors for psychiatric

Asthmatics exhibit altered oxylipin profiles compared to healthy individuals after subway air exposure.

Directory of Open Access Journals (Sweden)

Susanna L Lundström

Full Text Available Asthma is a chronic inflammatory lung disease that causes significant morbidity and mortality worldwide. Air pollutants such as particulate matter (PM and oxidants are important factors in causing exacerbations in asthmatics, and the source and composition of pollutants greatly affects pathological implications.This randomized crossover study investigated responses of the respiratory system to Stockholm subway air in asthmatics and healthy individuals. Eicosanoids and other oxylipins were quantified in the distal lung to provide a measure of shifts in lipid mediators in association with exposure to subway air relative to ambient air.Sixty-four oxylipins representing the cyclooxygenase (COX, lipoxygenase (LOX and cytochrome P450 (CYP metabolic pathways were screened using liquid chromatography-tandem mass spectrometry (LC-MS/MS of bronchoalveolar lavage (BAL-fluid. Validations through immunocytochemistry staining of BAL-cells were performed for 15-LOX-1, COX-1, COX-2 and peroxisome proliferator-activated receptor gamma (PPARγ. Multivariate statistics were employed to interrogate acquired oxylipin and immunocytochemistry data in combination with patient clinical information.Asthmatics and healthy individuals exhibited divergent oxylipin profiles following exposure to ambient and subway air. Significant changes were observed in 8 metabolites of linoleic- and α-linolenic acid synthesized via the 15-LOX pathway, and of the COX product prostaglandin E(2 (PGE(2. Oxylipin levels were increased in healthy individuals following exposure to subway air, whereas asthmatics evidenced decreases or no change.Several of the altered oxylipins have known or suspected bronchoprotective or anti-inflammatory effects, suggesting a possible reduced anti-inflammatory response in asthmatics following exposure to subway air. These observations may have ramifications for sensitive subpopulations in urban areas.

Asthmatics exhibit altered oxylipin profiles compared to healthy individuals after subway air exposure.

Science.gov (United States)

Lundström, Susanna L; Levänen, Bettina; Nording, Malin; Klepczynska-Nyström, Anna; Sköld, Magnus; Haeggström, Jesper Z; Grunewald, Johan; Svartengren, Magnus; Hammock, Bruce D; Larsson, Britt-Marie; Eklund, Anders; Wheelock, Åsa M; Wheelock, Craig E

2011-01-01

Asthma is a chronic inflammatory lung disease that causes significant morbidity and mortality worldwide. Air pollutants such as particulate matter (PM) and oxidants are important factors in causing exacerbations in asthmatics, and the source and composition of pollutants greatly affects pathological implications. This randomized crossover study investigated responses of the respiratory system to Stockholm subway air in asthmatics and healthy individuals. Eicosanoids and other oxylipins were quantified in the distal lung to provide a measure of shifts in lipid mediators in association with exposure to subway air relative to ambient air. Sixty-four oxylipins representing the cyclooxygenase (COX), lipoxygenase (LOX) and cytochrome P450 (CYP) metabolic pathways were screened using liquid chromatography-tandem mass spectrometry (LC-MS/MS) of bronchoalveolar lavage (BAL)-fluid. Validations through immunocytochemistry staining of BAL-cells were performed for 15-LOX-1, COX-1, COX-2 and peroxisome proliferator-activated receptor gamma (PPARγ). Multivariate statistics were employed to interrogate acquired oxylipin and immunocytochemistry data in combination with patient clinical information. Asthmatics and healthy individuals exhibited divergent oxylipin profiles following exposure to ambient and subway air. Significant changes were observed in 8 metabolites of linoleic- and α-linolenic acid synthesized via the 15-LOX pathway, and of the COX product prostaglandin E(2) (PGE(2)). Oxylipin levels were increased in healthy individuals following exposure to subway air, whereas asthmatics evidenced decreases or no change. Several of the altered oxylipins have known or suspected bronchoprotective or anti-inflammatory effects, suggesting a possible reduced anti-inflammatory response in asthmatics following exposure to subway air. These observations may have ramifications for sensitive subpopulations in urban areas.

Managing Recurrent Congestion of Subway Network in Peak Hours with Station Inflow Control

OpenAIRE

Qingru Zou; Xiangming Yao; Peng Zhao; Fei Dou; Taoyuan Yang

2018-01-01

Station inflow control (SIC) is an important and effective method for reducing recurrent congestion during peak hours in the Beijing, Shanghai, and Guangzhou subway systems. This work proposes a practical and efficient method for establishing a static SIC scheme in normal weekdays for large-scale subway networks. First, a traffic assignment model without capacity constraint is utilized to determine passenger flow distributions on the network. An internal relationship between station inflows a...

SIRS Model of Passengers’ Panic Propagation under Self-Organization Circumstance in the Subway Emergency

Directory of Open Access Journals (Sweden)

Haifeng Zhao

2014-01-01

Full Text Available Subway emergency may lead to passengers’ panic, especially under self-organizing circumstance, which will spread rapidly and have an adverse impact on the society. This paper builds an improved SIRS model of passengers’ panic spread in subway emergency with consideration of passengers’ density, the characteristic of subway car with the confined space, and passengers’ psychological factors. The spread of passengers’ panic is simulated by use of Matlab, which draws the rules of how group panic spreads dynamically. The trend of stable point of the infection ratio is analyzed by changing different parameters, which help to draw a conclusion that immunization rate, spontaneous immune loss rate, and passenger number have a great influence on the final infected ratio. Finally, we propose an integrated control strategy and find the peak of passengers’ panic and the final infected ratio is greatly improved through the numerical simulation. The research plays a vital role in helping the government and subway administration to master the panic spread mechanism and reduce the panic spread by improving measures and also provides certain reference significance for rail system construction, emergency contingency plans, and the construction and implementation of emergency response system.

Polycyclic aromatic hydrocarbons (PAH) and diesel engine emission (elemental carbon) inside a car and a subway train.

Science.gov (United States)

Fromme, H; Oddoy, A; Piloty, M; Krause, M; Lahrz, T

1998-06-30

Significant concentrations of potentially harmful substances can be present in the interior of vehicles. The main sources of PAHs and elemental carbon (EC) inside a car are likely to be combustion emissions, especially from coal and traffic. The same sources can also be important for the interior of a subway train for which there are specific sources in the tunnel system, for example diesel engines. Twice, in summer 1995 and winter 1996 polycyclic aromatic hydrocarbons (PAH) and diesel motor emission (estimated as elemental carbon) were determined in the interior of a car (a 2-year-old VW Golf with a three-way catalytic converter) and in the passenger compartment of a subway train (below ground). On each sampling day (in total 16 daily measurements in the car and 16 in the subway) the substances were determined in the breathing zone of the passengers from 07:00 h to 16:00 h under different meteorologic conditions (winter- and summertime). The car followed the route of the subway from the western Berlin borough of Spandau to the south-eastern borough of Neukölln, and back. The sampling represented a realistic exposure model for driving in a high traffic and polluted urban area. The electric subway train (also 2 years in use) connected the same parts of Berlin (31 km underground). The mean values obtained during the two measurement periods (summer/winter) inside the car were 1.0 and 3.2 ng/m3 for benzo[a]pyrene, 10.2 and 28.7 ng/m3 for total-measured-PAHs, 14.1 and 8.2 micrograms/m3 for EC and in the subway 0.7 and 4.0 ng/m3 for benzol[a]pyrene, 30.2 and 67.5 ng/m3 for total PAHs, 109 and 6.9 micrograms/m3 for EC. A comparison between subway and car exposures shows significantly higher concentrations of PAHs in the subway train, which can be explained by relatively high concentrations of fluoranthene and pyrene in the subway. So far a satisfactory explanation has not been found, but one source might be the wooden railway ties which were formerly preserved with tar

Master equation approach to the intra-urban passenger flow and application to the Metropolitan Seoul Subway system

Energy Technology Data Exchange (ETDEWEB)

Lee, Keumsook [Department of Geography, Sungshin University, Seoul 136-742 (Korea, Republic of); Goh, Segun; Choi, M Y [Department of Physics and Astronomy and Center for Theoretical Physics, Seoul National University, Seoul 151-747 (Korea, Republic of); Park, Jong Soo [School of Information Technology, Sungshin University, Seoul 136-742 (Korea, Republic of); Jung, Woo-Sung, E-mail: kslee@sungshin.ac.kr, E-mail: mychoi@snu.ac.kr [Department of Physics and Basic Science Research Institute, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of)

2011-03-18

The master equation approach is proposed to describe the evolution of passengers in a subway system. With the transition rate constructed from simple geographical consideration, the evolution equation for the distribution of subway passengers is found to bear skew distributions including log-normal, Weibull, and power-law distributions. This approach is then applied to the Metropolitan Seoul Subway system: analysis of the trip data of all passengers in a day reveals that the data in most cases fit well to the log-normal distributions. Implications of the results are also discussed.

Master equation approach to the intra-urban passenger flow and application to the Metropolitan Seoul Subway system

International Nuclear Information System (INIS)

Lee, Keumsook; Goh, Segun; Choi, M Y; Park, Jong Soo; Jung, Woo-Sung

2011-01-01

The master equation approach is proposed to describe the evolution of passengers in a subway system. With the transition rate constructed from simple geographical consideration, the evolution equation for the distribution of subway passengers is found to bear skew distributions including log-normal, Weibull, and power-law distributions. This approach is then applied to the Metropolitan Seoul Subway system: analysis of the trip data of all passengers in a day reveals that the data in most cases fit well to the log-normal distributions. Implications of the results are also discussed.

Transplanetary subway systems

Energy Technology Data Exchange (ETDEWEB)

Salter, R M

1978-10-01

Planetran, a global subway system consisting of carriages that are electromagnetically supported and propelled through evacuated tubes, is proposed. Speeds of 300 mph have been attained by transit vehicles using magnetic levitation. The fastest Planetran route modeled assumes a maximum speed of 14,000 mph and one gravity propulsion. Passenger response to high acceleration is unknown. The cost of a U.S. coast to coast system is estimated at $500 billion. Advantages include high speed transport, energy efficiency, reduced pollution, less land taken from agriculture, and associated benefits of transporting other materials in adjacent pipelines. No new scientific breakthroughs would be needed to develop this system. Military sponsorship is proposed to overcome resistance to the considerable financial outlay. (7 diagrams, 1 map)

Subway emergency preparedness in Shanghai: A focused group and interview study exploring the perceived experiences of senior citizens and the disabled.

Science.gov (United States)

Baffoe, Benjamin Ohene Kwapong; Shiyuan, Zheng

As Shanghai's population increases and currently being boosted by an influx of foreigners, there has been pressure on the subway system and this has led to a great concern for the aged and disabled people (including foreigners) who use the subway during emergency situations. The present study uses an exploratory research approach including a focus group discussion (FGD) and interviews to uncover the experiences, safety concerns, and challenges that the aged and disabled faces when using the subway. A total of 38 participants were involved in the study, which comprises of three FGDs and interviews conducted in the city of Shanghai. The findings reveal that most aged and disabled subway riders have little or no knowledge about emergency safety measures or safety symbols, the administering of first aid and have language barrier concerns. This study recommends that policy makers and sub-way operators should get the aged and disabled people involved in developing more educational programs that will help them to better the concept of safety prevention measures and it also suggests holding more emergency drills involving the aged and disabled. Braille language symbols, sign languages on TV screens, specially designed sub-way maps, low-frequency alarms with flashing lights, and information printed in multiple international languages should also be provided to help foreigners understand the instructions and information in the subways. Additionally, these measures could help all commuters to feel safer when using the subway.

Characterisation of nano- and micron-sized airborne and collected subway particles, a multi-analytical approach.

Science.gov (United States)

Midander, Klara; Elihn, Karine; Wallén, Anna; Belova, Lyuba; Karlsson, Anna-Karin Borg; Wallinder, Inger Odnevall

2012-06-15

Continuous daily measurements of airborne particles were conducted during specific periods at an underground platform within the subway system of the city center of Stockholm, Sweden. Main emphasis was placed on number concentration, particle size distribution, soot content (analyzed as elemental and black carbon) and surface area concentration. Conventional measurements of mass concentrations were conducted in parallel as well as analysis of particle morphology, bulk- and surface composition. In addition, the presence of volatile and semi volatile organic compounds within freshly collected particle fractions of PM(10) and PM(2.5) were investigated and grouped according to functional groups. Similar periodic measurements were conducted at street level for comparison. The investigation clearly demonstrates a large dominance in number concentration of airborne nano-sized particles compared to coarse particles in the subway. Out of a mean particle number concentration of 12000 particles/cm(3) (7500 to 20000 particles/cm(3)), only 190 particles/cm(3) were larger than 250 nm. Soot particles from diesel exhaust, and metal-containing particles, primarily iron, were observed in the subway aerosol. Unique measurements on freshly collected subway particle size fractions of PM(10) and PM(2.5) identified several volatile and semi-volatile organic compounds, the presence of carcinogenic aromatic compounds and traces of flame retardants. This interdisciplinary and multi-analytical investigation aims to provide an improved understanding of reported adverse health effects induced by subway aerosols. Copyright © 2012 Elsevier B.V. All rights reserved.

Airborne particulate metals in the New York City subway: A pilot study to assess the potential for health impacts✩,✩✩

Science.gov (United States)

Grass, David S.; Ross, James M.; Family, Farnosh; Barbour, Jonathan; Simpson, H. James; Coulibaly, Drissa; Hernandez, Jennifer; Chen, Yingdi; Slavkovich, Vesna; Li, Yongliang; Graziano, Joseph; Santella, Regina M.; Brandt-Rauf, Paul; Chillrud, Steven N.

2011-01-01

A prior study in New York City observed that airborne concentrations of three metals found in steel – iron, manganese, and chromium – are more than 100 times higher in the subway system than in aboveground air. To investigate the potential for health effects of exposure at these levels, we conducted a pilot study of subway workers comparing personal exposures to steel dust with biomarkers of metal exposure, oxidative stress, and DNA damage in blood and urine samples. Workers wore a personal air sampler operating at 4 L/m for one to three work shifts with blood and urine samples collected at the end of the final shift. We found that PM2.5 exposures varied among subway workers on the basis of job title and job activity. The subway workers’ mean time-weighted PM2.5 exposure was 52 µg/m3, with a median of 27 µg/m3, and a range of 6–469 µg/m3. The observed concentrations of PM2.5, iron, manganese, and chromium fell well below occupational standards. Biomarker concentrations among the 39 subway workers were compared with a group of 11 bus drivers, and a group of 25 suburban office workers. Concentrations of DNA–protein crosslinks and chromium in plasma were significantly higher in subway workers than in bus drivers, but no significant difference was observed for these biomarkers between subway workers and office workers. Urinary isoprostane concentrations were significantly correlated with the number of years working in the subway system, and were detected at higher, though not significantly higher, concentrations in subway workers than in bus drivers or office workers. At the group level, there was no consistent pattern of biomarker concentrations among subway workers significantly exceeding those of the bus drivers and office workers. At the individual level, steel dust exposure was not correlated with any of the biomarkers measured. PMID:19926083

Urban air quality comparison for bus, tram, subway and pedestrian commutes in Barcelona.

Science.gov (United States)

Moreno, Teresa; Reche, Cristina; Rivas, Ioar; Cruz Minguillón, Maria; Martins, Vânia; Vargas, Concepción; Buonanno, Giorgio; Parga, Jesus; Pandolfi, Marco; Brines, Mariola; Ealo, Marina; Sofia Fonseca, Ana; Amato, Fulvio; Sosa, Garay; Capdevila, Marta; de Miguel, Eladio; Querol, Xavier; Gibbons, Wes

2015-10-01

Access to detailed comparisons in air quality variations encountered when commuting through a city offers the urban traveller more informed choice on how to minimise personal exposure to inhalable pollutants. In this study we report on an experiment designed to compare atmospheric contaminants inhaled during bus, subway train, tram and walking journeys through the city of Barcelona. Average number concentrations of particles 10-300 nm in size, N, are lowest in the commute using subway trains (N5.0×10(4) cm(-3)), with extreme transient peaks at busy traffic crossings commonly exceeding 1.0×10(5) cm(-3) and accompanied by peaks in Black Carbon and CO. Subway particles are coarser (mode 90 nm) than in buses, trams or outdoors (1200 ppm in crowded buses and trains. There are also striking differences in inhalable particle chemistry depending on the route chosen, ranging from aluminosiliceous at roadsides and near pavement works, ferruginous with enhanced Mn, Co, Zn, Sr and Ba in the subway environment, and higher levels of Sb and Cu inside the bus. We graphically display such chemical variations using a ternary diagram to emphasise how "air quality" in the city involves a consideration of both physical and chemical parameters, and is not simply a question of measuring particle number or mass. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Weighted complex network analysis of the Beijing subway system: Train and passenger flows

Science.gov (United States)

Feng, Jia; Li, Xiamiao; Mao, Baohua; Xu, Qi; Bai, Yun

2017-05-01

In recent years, complex network theory has become an important approach to the study of the structure and dynamics of traffic networks. However, because traffic data is difficult to collect, previous studies have usually focused on the physical topology of subway systems, whereas few studies have considered the characteristics of traffic flows through the network. Therefore, in this paper, we present a multi-layer model to analyze traffic flow patterns in subway networks, based on trip data and an operation timetable obtained from the Beijing Subway System. We characterize the patterns in terms of the spatiotemporal flow size distributions of both the train flow network and the passenger flow network. In addition, we describe the essential interactions between these two networks based on statistical analyses. The results of this study suggest that layered models of transportation systems can elucidate fundamental differences between the coexisting traffic flows and can also clarify the mechanism that causes these differences.

Chemical speciation of size-segregated floor dusts and airborne magnetic particles collected at underground subway stations in Seoul, Korea

Energy Technology Data Exchange (ETDEWEB)

Jung, Hae-Jin; Kim, BoWha; Malek, Md Abdul [Department of Chemistry, Inha University, 253, Yonghyun-dong, Nam-gu, Incheon 402-751 (Korea, Republic of); Koo, Yong Sung; Jung, Jong Hoon [Department of Physics, Inha University, 253, Yonghyun-dong, Nam-gu, Incheon 402-751 (Korea, Republic of); Son, Youn-Suk [Department of Advanced Technology Fusion, Konkuk University, Seoul 143-701 (Korea, Republic of); Kim, Jo-Chun [Department of Advanced Technology Fusion, Konkuk University, Seoul 143-701 (Korea, Republic of); Department of Environmental Engineering, Konkuk University, Seoul 143-701 (Korea, Republic of); Kim, HyeKyoung [Department of Chemistry, Inha University, 253, Yonghyun-dong, Nam-gu, Incheon 402-751 (Korea, Republic of); Ro, Chul-Un, E-mail: curo@inha.ac.kr [Department of Chemistry, Inha University, 253, Yonghyun-dong, Nam-gu, Incheon 402-751 (Korea, Republic of)

2012-04-30

Highlights: Black-Right-Pointing-Pointer We examined chemical species of floor dusts and airborne magnetic subway particles collected at underground subway stations. Black-Right-Pointing-Pointer XRD, SEM/EDX, and VSM measurements provided information on their major iron species, which is relatively harmless iron metal. Black-Right-Pointing-Pointer PM levels at underground subway stations can be controlled by removing magnetic indoor particles using magnets. - Abstract: Previous studies have reported the major chemical species of underground subway particles to be Fe-containing species that are generated from wear and friction processes at rail-wheel-brake and catenaries-pantographs interfaces. To examine chemical composition of Fe-containing particles in more details, floor dusts were collected at five sampling locations of an underground subway station. Size-segregated floor dusts were separated into magnetic and non-magnetic fractions using a permanent magnet. Using X-ray diffraction (XRD) and scanning electron microscopy/energy dispersive X-ray spectrometry (SEM/EDX), iron metal, which is relatively harmless, was found to be the dominating chemical species in the floor dusts of the <25 {mu}m size fractions with minor fractions of Mg, Al, Si, Ca, S, and C. From SEM analysis, the floor dusts of the <25 {mu}m size fractions collected on railroad ties appeared to be smaller than 10 {mu}m, indicating that their characteristics should somewhat reflect the characteristics of airborne particles in the tunnel and the platform. As most floor dusts are magnetic, PM levels at underground subway stations can be controlled by removing magnetic indoor particles using magnets. In addition, airborne subway particles, most of which were smaller than 10 {mu}m, were collected using permanent magnets at two underground subway stations, namely Jegi and Yangjae stations, in Seoul, Korea. XRD and SEM/EDX analyses showed that most of the magnetic aerosol particles collected at Jegi

Chemical speciation of size-segregated floor dusts and airborne magnetic particles collected at underground subway stations in Seoul, Korea

International Nuclear Information System (INIS)

Jung, Hae-Jin; Kim, BoWha; Malek, Md Abdul; Koo, Yong Sung; Jung, Jong Hoon; Son, Youn-Suk; Kim, Jo-Chun; Kim, HyeKyoung; Ro, Chul-Un

2012-01-01

Highlights: ► We examined chemical species of floor dusts and airborne magnetic subway particles collected at underground subway stations. ► XRD, SEM/EDX, and VSM measurements provided information on their major iron species, which is relatively harmless iron metal. ► PM levels at underground subway stations can be controlled by removing magnetic indoor particles using magnets. - Abstract: Previous studies have reported the major chemical species of underground subway particles to be Fe-containing species that are generated from wear and friction processes at rail–wheel–brake and catenaries–pantographs interfaces. To examine chemical composition of Fe-containing particles in more details, floor dusts were collected at five sampling locations of an underground subway station. Size-segregated floor dusts were separated into magnetic and non-magnetic fractions using a permanent magnet. Using X-ray diffraction (XRD) and scanning electron microscopy/energy dispersive X-ray spectrometry (SEM/EDX), iron metal, which is relatively harmless, was found to be the dominating chemical species in the floor dusts of the <25 μm size fractions with minor fractions of Mg, Al, Si, Ca, S, and C. From SEM analysis, the floor dusts of the <25 μm size fractions collected on railroad ties appeared to be smaller than 10 μm, indicating that their characteristics should somewhat reflect the characteristics of airborne particles in the tunnel and the platform. As most floor dusts are magnetic, PM levels at underground subway stations can be controlled by removing magnetic indoor particles using magnets. In addition, airborne subway particles, most of which were smaller than 10 μm, were collected using permanent magnets at two underground subway stations, namely Jegi and Yangjae stations, in Seoul, Korea. XRD and SEM/EDX analyses showed that most of the magnetic aerosol particles collected at Jegi station was iron metal, whereas those at Yangjae station contained a small amount

49 CFR 1242.15 - Roadway, tunnels and subways, bridges and culverts, ties, rails, other track material, ballast...

Science.gov (United States)

2010-10-01

... 49 Transportation 9 2010-10-01 2010-10-01 false Roadway, tunnels and subways, bridges and culverts, ties, rails, other track material, ballast, track laying and surfacing, and road property damaged... RAILROADS 1 Operating Expenses-Way and Structures § 1242.15 Roadway, tunnels and subways, bridges and...

Formation and alteration of airborne particles in the subway environment.

Science.gov (United States)

Moreno, T; Querol, X; Martins, V; Minguillón, M C; Reche, C; Ku, L H; Eun, H R; Ahn, K H; Capdevila, M; de Miguel, E

2017-01-25

Most particles in the rail subway environment are sub-micron sized ferruginous flakes and splinters generated mechanically by frictional wear of brake pads, wheels and rails. To better understand the mechanisms of formation and the alteration processes affecting inhalable particles in subways, PM samples (1-2.5 μm and 2.5-10 μm) were collected in the Barcelona Metro and then studied under a scanning electron microscope. Most particles in these samples are hematitic (up to 88%), with relatively minor amounts of mineral matter (up to 9%) and sulphates (up to 5%). Detailed microscopy (using back scattered and TEM-DRX imaging) reveals how many of the metallic particles comprise the metallic Fe nucleus surrounded by hematite (Fe 2 O 3 ) and a coating of sulphate and chloride salts mixed with mineral matter (including Ca-carbonates, clay minerals and quartz). These observations record the emission of fine to ultrafine FePM by frictional wear at elevated temperatures that promote rapid partial (or complete) oxidation of the native metal. Water condensing on the PM surface during cooling leads to the adsorption of inorganic mineral particles that coat the iron oxide. The distinctively layered polymineralic structure that results from these processes is peculiar to particles generated in the subway environment and very different from PM typically inhaled outdoors.

Chemical speciation of size-segregated floor dusts and airborne magnetic particles collected at underground subway stations in Seoul, Korea.

Science.gov (United States)

Jung, Hae-Jin; Kim, BoWha; Malek, Md Abdul; Koo, Yong Sung; Jung, Jong Hoon; Son, Youn-Suk; Kim, Jo-Chun; Kim, HyeKyoung; Ro, Chul-Un

2012-04-30

Previous studies have reported the major chemical species of underground subway particles to be Fe-containing species that are generated from wear and friction processes at rail-wheel-brake and catenaries-pantographs interfaces. To examine chemical composition of Fe-containing particles in more details, floor dusts were collected at five sampling locations of an underground subway station. Size-segregated floor dusts were separated into magnetic and non-magnetic fractions using a permanent magnet. Using X-ray diffraction (XRD) and scanning electron microscopy/energy dispersive X-ray spectrometry (SEM/EDX), iron metal, which is relatively harmless, was found to be the dominating chemical species in the floor dusts of the subway stations can be controlled by removing magnetic indoor particles using magnets. In addition, airborne subway particles, most of which were smaller than 10 μm, were collected using permanent magnets at two underground subway stations, namely Jegi and Yangjae stations, in Seoul, Korea. XRD and SEM/EDX analyses showed that most of the magnetic aerosol particles collected at Jegi station was iron metal, whereas those at Yangjae station contained a small amount of Fe mixed with Na, Mg, Al, Si, S, Ca, and C. The difference in composition of the Fe-containing particles between the two subway stations was attributed to the different ballast tracks used. Copyright © 2012 Elsevier B.V. All rights reserved.

Transient variation of aerosol size distribution in an underground subway station.

Science.gov (United States)

Kwon, Soon-Bark; Namgung, Hyeong-Gyu; Jeong, Wootae; Park, Duckshin; Eom, Jin Ki

2016-06-01

As the number of people using rapid transit systems (subways) continues to rise in major cities worldwide, increasing attention has been given to the indoor air quality of underground stations. This study intended to observe the change of PM distribution by size in an underground station with PSDs installed located near the main road in downtown Seoul, as well as to examine causes for the changes. The results indicate that the PM suspended in the tunnel flowed into the platform area even in a subway station where the effect of train-induced wind is blocked by installed PSDs, as this flow occurred when the PSDs were opened. The results also indicate that coarse mode particles generated by mechanical friction in the tunnel, such as that between wheels and rail, also flowed into the platform area. The PM either settled or was re-suspended according to size and whether the ventilation in the platform area was in operation or if the platform floor had been washed. The ventilation system was more effective in removing PM of smaller sizes (fine particles) while the wash-out performed after train operations had stopped reduced the suspension of coarse mode particles the next morning. Despite installation of the completely sealed PSDs, inflow of coarse mode particles from the tunnel seems unavoidable, indicating the need for measures to decrease the PM generated there to lower subway user exposure since those particles cannot be reduced by mechanical ventilation alone. This research implicate that coarse PM containing heavy metals (generated from tunnel side) proliferated especially during rush hours, during which it is very important to control those PM in order to reduce subway user exposure to this hazardous PM.

Geotectonic variations of radon fields in Tashkent subway stations

International Nuclear Information System (INIS)

Yafasov, A.Ya.; Akimov, V.A.

2001-01-01

The anomalies of radon fields in the air of stations of Tashkent subway were investigated. These stations are located in areas with different tectonic characteristics. The influence of tectonic anomalies on formation and variations of radon fields in the environment was shown. (author)

Investigation of Magnetic Field in the Subway Station

Directory of Open Access Journals (Sweden)

Ctibor Henzl

2006-01-01

Full Text Available Paper deals with computing of magnetic field in the rails surroundings of subway (underground. The calculation of field is made by using of an analytical method in Excel VBA. There is also used commercial FEM software ANSYS and finite element method. Output results of the both methods are finally compared.

Manganese concentrations in the air of the Montreal (Canada) subway in relation to surface automobile traffic density

Energy Technology Data Exchange (ETDEWEB)

Boudia, Nacera; Gareau, Lise; Zayed, Joseph [GRIS Interdisciplinary Health Research Group, University of Montreal (Canada); Halley, Renee [Transport Montreal Society (Canada); Kennedy, Greg [Department of Engineering Physics, Ecole Polytechnique de Montreal, Montreal (Canada); Lambert, Jean [Department of Social and Preventive Medicine, Faculty of Medicine, University of Montreal (Canada)

2006-07-31

Methylcyclopentadienyl manganese tricarbonyl (MMT) is an organic derivative of manganese (Mn), used since 1976 in Canadian gasoline as an octane enhancer. Its combustion leads to the emission of Mn particles. Several studies carried out by our research group have established a correlation between atmospheric Mn concentrations and automobile traffic density, suggesting that MMT in gasoline could play a significant role. This study aims to measure Mn concentrations in the air of the underground subway in Montreal (Canada) and to examine the relation with nearby surface automobile traffic density and, by extension, with the use of MMT in gasoline. Three subway stations were chosen for their location in different microenvironments with different traffic densities. Respirable (MnR<5 {mu}m) and total Mn (MnT) were sampled over two weeks, 5 days/week, 12 h/day. For the station located in the lower traffic density area, relatively low levels of MnR and MnT were found, with averages of 0.018 and 0.032 {mu}g/m{sup 3}, respectively. These concentrations are within the range of the background levels in Montreal. For the other two stations, the average concentrations of MnR were twice as high and exceeded the US EPA reference concentration of 0.05 {mu}g/m{sup 3}. Although there may be several sources of Mn from different components of the subway structure and vehicles, no correlation was found between subway traffic and atmospheric Mn in the subway. Since the air in the underground subway is pumped directly from outside without filtration, our findings strongly suggest that the combustion of MMT in automobiles is an important factor. (author)

Effectiveness of Physical Barriers Installation for Prevention of Incidents in Mexico City’s Subway System

OpenAIRE

Portillo-Villasana, Gerardo de Jesús; Huerta-Barrientos, Aida; Dillarza Andrade, Yazmin

2017-01-01

Nowadays, suicides inside the installations of subway platforms are considered a public health problem in Mexico City. One solution to prevent them is the installation of physical barriers, but their high cost is unattractive for governmental authorities. Traditional approaches of research on the effectiveness of physical barriers for preventing suicides have been limited to analyzing statistically the effects of installing platform screen doors and blue lights on subway platforms. Although c...

a New Approach for Subway Tunnel Deformation Monitoring: High-Resolution Terrestrial Laser Scanning

Science.gov (United States)

Li, J.; Wan, Y.; Gao, X.

2012-07-01

With the improvement of the accuracy and efficiency of laser scanning technology, high-resolution terrestrial laser scanning (TLS) technology can obtain high precise points-cloud and density distribution and can be applied to high-precision deformation monitoring of subway tunnels and high-speed railway bridges and other fields. In this paper, a new approach using a points-cloud segmentation method based on vectors of neighbor points and surface fitting method based on moving least squares was proposed and applied to subway tunnel deformation monitoring in Tianjin combined with a new high-resolution terrestrial laser scanner (Riegl VZ-400). There were three main procedures. Firstly, a points-cloud consisted of several scanning was registered by linearized iterative least squares approach to improve the accuracy of registration, and several control points were acquired by total stations (TS) and then adjusted. Secondly, the registered points-cloud was resampled and segmented based on vectors of neighbor points to select suitable points. Thirdly, the selected points were used to fit the subway tunnel surface with moving least squares algorithm. Then a series of parallel sections obtained from temporal series of fitting tunnel surfaces were compared to analysis the deformation. Finally, the results of the approach in z direction were compared with the fiber optical displacement sensor approach and the results in x, y directions were compared with TS respectively, and comparison results showed the accuracy errors of x, y, z directions were respectively about 1.5 mm, 2 mm, 1 mm. Therefore the new approach using high-resolution TLS can meet the demand of subway tunnel deformation monitoring.

Humans and Machines in the subway Humanos e máquinas no metrô

Directory of Open Access Journals (Sweden)

Janice Caiafa

2011-07-01

Full Text Available In this work we analyze the repercussions that the recent implementation of an electronic fare collection system - with smart cards – has brought to everyday life of subway riders in Rio de Janeiro. The adoption of a fare collection system involves the choice of a technology and the stipulation of a charging system. By following this technological evolution in Rio de Janeiro’s subway, we explore how its riders learn to approach the new interfaces with the automatic machines and to cope with the payment conditions, which are at the same time imposed. We note, in this context, how the technological devices are coupled to human actions regarding the construction of a new fare collection system as well as the sociability that is developed in the subway technological space.Resumo: Neste trabalho analisamos as repercussões que a recente implementação de um novo sistema de bilhetagem eletrônica trouxe para o quotidiano dos usuários do metrô do Rio de Janeiro. A adoção de um sistema de bilhetagem envolve a escolha de uma tecnologia e a estipulação de um regime de cobrança. Ao acompanhar essa evolução tecnológia no metrô do Rio de Janeiro, exploramos como os usuários têm aprendido a abordar as novas interfaces com as máquinas automáticas e enfrentado as condições de pagamento que no mesmo golpe são impostas. Observamos como as ferramentas tecnológicas se acoplam a ações humanas tanto no que diz respeito à própria construção do novo sistema quanto à sociabilidade que se desenvolve no espaço tecnológico do metrô. Palavras-Chave: Tecnologia; Metrô (Rio de Janeiro; Sociabilidade Abstract: In this work we analyze the repercussions of the recently implemented fare collection system with smart cards in the Rio de Janeiro subway. The implementation of a fare collection system involves opting for a certain technology as well as stipulating a regime of fare charging. As we follow this technological evolution in the Rio

The end of the line: The relationship between New York City's subway system and residential class structure

Science.gov (United States)

Rhindress, Mindy

Public money is necessary to build and maintain this country's vast network of mass transit systems and highways. Thus you would expect class equity in choices of infrastructure location, types of projects and pricing. However, the influence of commercial interests appears to create a contradictory effect, and may negatively influence the settlement patterns where transit serves. New York City and its subway system offered the perfect case study by which to examine the before and after effects of mass transit introduction given the enormous size of the transit system and the grand development of New York City that appeared to occur simultaneous to subway inauguration. The main objective of this study was to determine the relationship between the growth of the New York City subway system and the establishment of class structure in residential patterns. Regional census data covering the first 16-year period of the subway's development was examined along with geographic statistics on subway line expansion and station openings. GIS (Geographic Information Systems) maps were used to illustrate the development of living spaces as a function of subway introduction into communities, and several Indices were computed to demonstrate the population growth and class disparity. The results revealed that the early years of transit development were entrepreneurial efforts coordinated by business interests. This led to transit first providing significant benefits mostly to the middle and upper classes, giving them a reasonable means by which to escape horrible tenement living conditions while turning a profit at the same time. Thus new settlements were stratified by class almost immediately after introduction. The cycle continued until years later when the automobile was introduced and the once expensive and luxurious, but now more reasonably priced and just functional, public transit system finally befit the population much lower on the socioeconomic scale. Class divisions still

Characterization of airborne bacteria at an underground subway station.

Science.gov (United States)

Dybwad, Marius; Granum, Per Einar; Bruheim, Per; Blatny, Janet Martha

2012-03-01

The reliable detection of airborne biological threat agents depends on several factors, including the performance criteria of the detector and its operational environment. One step in improving the detector's performance is to increase our knowledge of the biological aerosol background in potential operational environments. Subway stations are enclosed public environments, which may be regarded as potential targets for incidents involving biological threat agents. In this study, the airborne bacterial community at a subway station in Norway was characterized (concentration level, diversity, and virulence- and survival-associated properties). In addition, a SASS 3100 high-volume air sampler and a matrix-assisted laser desorption ionization-time of flight mass spectrometry-based isolate screening procedure was used for these studies. The daytime level of airborne bacteria at the station was higher than the nighttime and outdoor levels, and the relative bacterial spore number was higher in outdoor air than at the station. The bacterial content, particle concentration, and size distribution were stable within each environment throughout the study (May to September 2010). The majority of the airborne bacteria belonged to the genera Bacillus, Micrococcus, and Staphylococcus, but a total of 37 different genera were identified in the air. These results suggest that anthropogenic sources are major contributors to airborne bacteria at subway stations and that such airborne communities could harbor virulence- and survival-associated properties of potential relevance for biological detection and surveillance, as well as for public health. Our findings also contribute to the development of realistic testing and evaluation schemes for biological detection/surveillance systems by providing information that can be used to mimic real-life operational airborne environments in controlled aerosol test chambers.

Characterization of Airborne Bacteria at an Underground Subway Station

Science.gov (United States)

Dybwad, Marius; Granum, Per Einar; Bruheim, Per

2012-01-01

The reliable detection of airborne biological threat agents depends on several factors, including the performance criteria of the detector and its operational environment. One step in improving the detector's performance is to increase our knowledge of the biological aerosol background in potential operational environments. Subway stations are enclosed public environments, which may be regarded as potential targets for incidents involving biological threat agents. In this study, the airborne bacterial community at a subway station in Norway was characterized (concentration level, diversity, and virulence- and survival-associated properties). In addition, a SASS 3100 high-volume air sampler and a matrix-assisted laser desorption ionization–time of flight mass spectrometry-based isolate screening procedure was used for these studies. The daytime level of airborne bacteria at the station was higher than the nighttime and outdoor levels, and the relative bacterial spore number was higher in outdoor air than at the station. The bacterial content, particle concentration, and size distribution were stable within each environment throughout the study (May to September 2010). The majority of the airborne bacteria belonged to the genera Bacillus, Micrococcus, and Staphylococcus, but a total of 37 different genera were identified in the air. These results suggest that anthropogenic sources are major contributors to airborne bacteria at subway stations and that such airborne communities could harbor virulence- and survival-associated properties of potential relevance for biological detection and surveillance, as well as for public health. Our findings also contribute to the development of realistic testing and evaluation schemes for biological detection/surveillance systems by providing information that can be used to mimic real-life operational airborne environments in controlled aerosol test chambers. PMID:22247150

Noise pollution survey of a two-storey intersection station in Tehran metropolitan subway system.

Science.gov (United States)

Ghotbi, Mohammad Reza; Monazzam, Mohammad Reza; Baneshi, Mohammad Reza; Asadi, Mohammad; Fard, Samaneh Momen Bellah

2012-01-01

According to the world population increase and demand on transportation in mega cities, modern and low-cost technologies are remarkably considered. Meanwhile, subway system, as a means to transfer a large population of people, is extremely welcomed due to its particular advantages including time and cost savings, traffic jam avoidance, and unaffected by weather. Nevertheless, despite the benefits of these technologies, such devices also have been associated with disadvantages for human. In many subway systems, noisy environments are clearly observed; therefore, workers and even the passengers are exposed to higher noise levels than permissible limit. In this research, noise measurements were performed at Imam Khomeini Station as the most crowded intersection subway station in Tehran. In this descriptive-sectional survey, the amount of noise pollution was investigated at both stories of Imam Khomeini Intersection Station. A variety of noise pollution indicators such as L(eq) 10 min were separately measured at each storey through five measurement points from 7 A.M. to 10 P.M. It was shown that the equivalent sound level range at Imam Khomeini station towards Elmo Sanat and Imam Khomeini towards Mirdamad were between 70.56-79.54 and 68.35-79.12 dB (A), respectively. It was indicated that except for the entrance stairs to the subway waiting platform and the first section of the platform on both stories, other measurement stations have the same equivalent sound levels.

A new look at inhalable metalliferous airborne particles on rail subway platforms.

Science.gov (United States)

Moreno, Teresa; Martins, Vânia; Querol, Xavier; Jones, Tim; BéruBé, Kelly; Minguillón, Maria Cruz; Amato, Fulvio; Capdevila, Marta; de Miguel, Eladio; Centelles, Sonia; Gibbons, Wes

2015-02-01

Most particles breathed on rail subway platforms are highly ferruginous (FePM) and extremely small (nanometric to a few microns in size). High magnification observations of particle texture and chemistry on airborne PM₁₀ samples collected from the Barcelona Metro, combined with published experimental work on particle generation by frictional sliding, allow us to propose a general model to explain the origin of most subway FePM. Particle generation occurs by mechanical wear at the brake-wheel and wheel-rail interfaces, where magnetic metallic flakes and splinters are released and undergo progressive atmospheric oxidation from metallic iron to magnetite and maghemite. Flakes of magnetite typically comprise mottled mosaics of octahedral nanocrystals (10-20 nm) that become pseudomorphed by maghemite. Continued oxidation results in extensive alteration of the magnetic nanostructure to more rounded aggregates of non-magnetic hematite nanocrystals, with magnetic precursors (including iron metal) still preserved in some particle cores. Particles derived from steel wheel and rails contain a characteristic trace element chemistry, typically with Mn/Fe=0.01. Flakes released from brakes are chemically very distinctive, depending on the pad composition, being always carbonaceous, commonly barium-rich, and texturally inhomogeneous, with trace elements present in nanominerals incorporated within the crystalline structure. In the studied subway lines of Barcelona at least there appears to be only a minimal aerosol contribution from high temperature processes such as sparking. To date there is no strong evidence that these chemically and texturally complex inhalable metallic materials are any more or less toxic than street-level urban particles, and as with outdoor air, the priority in subway air quality should be to reduce high mass concentrations of aerosol present in some stations. Copyright © 2014. Published by Elsevier B.V.

Saturday Subway Ride: A Report on the Initial Tryout.

Science.gov (United States)

Quilling, Mary R.; And Others

"Saturday Subway Ride," a program designed to teach pupils creative thinking techniques and positive attitudes toward creative ideas, is a 92-page workbook in a story-exercise format. Secondary objectives for the product include improving verbal fluency and creative writing. Three classrooms 61 sixth graders and 34 fifth graders at two…

Cycling for Transportation in Sao Paulo City: Associations with Bike Paths, Train and Subway Stations.

Science.gov (United States)

Florindo, Alex Antonio; Barrozo, Ligia Vizeu; Turrell, Gavin; Barbosa, João Paulo Dos Anjos Souza; Cabral-Miranda, William; Cesar, Chester Luiz Galvão; Goldbaum, Moisés

2018-03-21

Cities that support cycling for transportation reap many public health benefits. However, the prevalence of this mode of transportation is low in Latin American countries and the association with facilities such as bike paths and train/subway stations have not been clarified. We conducted a cross-sectional analysis of the relationship between bike paths, train/subway stations and cycling for transportation in adults from the city of Sao Paulo. We used data from the Sao Paulo Health Survey ( n = 3145). Cycling for transportation was evaluated by a questionnaire and bike paths and train/subway stations were geocoded using the geographic coordinates of the adults' residential addresses in 1500-m buffers. We used multilevel logistic regression, taking account of clustering by census tract and households. The prevalence of cycling for transportation was low (5.1%), and was more prevalent in males, singles, those active in leisure time, and in people with bicycle ownership in their family. Cycling for transportation was associated with bike paths up to a distance of 500 m from residences (OR (Odds Ratio) = 2.54, 95% CI (Confidence interval) 1.16-5.54) and with the presence of train/subway stations for distances >500 m from residences (OR = 2.07, 95% CI 1.10-3.86). These results are important to support policies to improve cycling for transportation in megacities such as Sao Paulo.

Optimal Locations of Bus Stops Connecting Subways near Urban Intersections

Directory of Open Access Journals (Sweden)

Yuan Cui

2015-01-01

Full Text Available Unsuitable locations of bus stops which provide feeder transportation connecting subways near urban intersections usually lead to the low efficiency of public transport and level of passenger service. A multiobjective optimization model to distribute such stop locations is proposed to attain the shortest total walk distance of passengers and minimum delay time of cars through intersections and travel time of buses. The Pareto frontier and optimal solutions for the proposed model are given by the distance-based and enumerative methods. The Xizhimen bus stop is selected to implement case studies for verifying the validity of the proposed model. The analysis of sensitivity on possible solutions is also carried out in the case studies. The results show that the proposed model is capable of optimizing the locations of bus stops connecting subways near intersections and helpful to improve the level of passengers service and operational efficiency of public transportation.

Modelling the Shifts in Activity Centres along the Subway Stations. The Case Study of Metropolitan Tehran

Directory of Open Access Journals (Sweden)

Ali Soltani

2016-10-01

Full Text Available Activity centers are areas of strong development of a particular activity, such as residence, employment, or services. Understanding the subway system impacts on the type, combination, distribution and totally the development of basic activities in these centers, have an important role in managing development opportunities created along the Tehran subway lines. The multi criteria and fuzzy nature of evaluating the activity centers development make the issue as complex as cannot be addressed with conventional logical systems. One of the most important methods of multi criteria evaluation is Fuzzy Inference System. Fuzzy inference system is a popular computing framework based on the concepts of Fuzzy Sets Theory, which is capable of accommodating inherent uncertainty in multi-criteria evaluation process. This paper analyze shifts in activity centers along two lines of the Tehran subway system based on three major criteria by designing a comprehensive fuzzy inference system. The data for the present study were collected through documentary analysis, questionnaires and semi-structured interview. The result revealed that the level of the subway system influence on the pattern and process of the development of activities varied with the location, physical environment and entity of each station. Furthermore, empirical findings indicated that the subway line might weaken residential activities while attracting employment and service activities to the city center. Specifically, residential estates moved away from the city center to the suburbs whereas employment and service activities expanded from the existing central business district (CBD. The results can be applied to suggest planning policies aiming at improving the effects of public transit on property developemnet and land use change in a developing country.

Characteristics of the elemental compositions of particulate matter at a subway platform using INAA and XRF

Energy Technology Data Exchange (ETDEWEB)

Lim, J.M.; Moon, J.H.; Chung, Y.S. [Korea Atomic Energy Research Insitute, Daejeon (Korea, Republic of). Dept. of Nuclear Basic Science; Jeong, J.H.; Jung, B.W.; Lee, J.H. [Chungnam National Univ., Daejeon (Korea, Republic of). Dept. of Environmental Engineering; Kim, K.H. [Sejong Univ., Seoul (Korea, Republic of). Dept. of Environment and Energy

2011-07-01

In this study, a total of 21 elements were determined from PM2.5 and PM10 samples collected at one subway station using INAA and XRF. In order to assess the pollution status and distribution characteristics in a subway station, the absolute concentration levels, concentration ratios, and crustal enrichment factors of these elements were analyzed. PM2.5 concentrations in the subway station varied in the range of 24.8 to 72.6 {mu}g m{sup -3} (average {+-} standard deviation: 42.6{+-}10.6 {mu}g m{sup -3}), while those of PM10 from 38.0 to 101 {mu}g m{sup -3} (67.2{+-}15.5 {mu}g m{sup -3}). The relative contribution of elemental components in each particle fraction accounted for about 42 and 44%, respectively. Out of all metals, Fe was predominant to represent about 29 and 27% of each particle fraction. In contrast, the crustal sources were estimated to contribute to about 3.7 and 2.3% of the total Fe concentrations, respectively. Thus, one can conclude that considerable quantities of airborne Fe particles originated mainly from subway sources, probably due to the wearing of the steel products like wheel, rail, brake, etc. (orig.)

Characteristics of the elemental compositions of particulate matter at a subway platform using INAA and XRF

International Nuclear Information System (INIS)

Lim, J.M.; Moon, J.H.; Chung, Y.S.; Jeong, J.H.; Jung, B.W.; Lee, J.H.; Kim, K.H.

2011-01-01

In this study, a total of 21 elements were determined from PM2.5 and PM10 samples collected at one subway station using INAA and XRF. In order to assess the pollution status and distribution characteristics in a subway station, the absolute concentration levels, concentration ratios, and crustal enrichment factors of these elements were analyzed. PM2.5 concentrations in the subway station varied in the range of 24.8 to 72.6 μg m -3 (average ± standard deviation: 42.6±10.6 μg m -3 ), while those of PM10 from 38.0 to 101 μg m -3 (67.2±15.5 μg m -3 ). The relative contribution of elemental components in each particle fraction accounted for about 42 and 44%, respectively. Out of all metals, Fe was predominant to represent about 29 and 27% of each particle fraction. In contrast, the crustal sources were estimated to contribute to about 3.7 and 2.3% of the total Fe concentrations, respectively. Thus, one can conclude that considerable quantities of airborne Fe particles originated mainly from subway sources, probably due to the wearing of the steel products like wheel, rail, brake, etc. (orig.)

Estimation of inhaled airborne particle number concentration by subway users in Seoul, Korea.

Science.gov (United States)

Kim, Minhae; Park, Sechan; Namgung, Hyeong-Gyu; Kwon, Soon-Bark

2017-12-01

Exposure to airborne particulate matter (PM) causes several diseases in the human body. The smaller particles, which have relatively large surface areas, are actually more harmful to the human body since they can penetrate deeper parts of the lungs or become secondary pollutants by bonding with other atmospheric pollutants, such as nitrogen oxides. The purpose of this study is to present the number of PM inhaled by subway users as a possible reference material for any analysis of the hazards to the human body arising from the inhalation of such PM. Two transfer stations in Seoul, Korea, which have the greatest number of users, were selected for this study. For 0.3-0.422 μm PM, particle number concentration (PNC) was highest outdoors but decreased as the tester moved deeper underground. On the other hand, the PNC between 1 and 10 μm increased as the tester moved deeper underground and showed a high number concentration inside the subway train as well. An analysis of the particles to which subway users are actually exposed to (inhaled particle number), using particle concentration at each measurement location, the average inhalation rate of an adult, and the average stay time at each location, all showed that particles sized 0.01-0.422 μm are mostly inhaled from the outdoor air whereas particles sized 1-10 μm are inhaled as the passengers move deeper underground. Based on these findings, we expect that the inhaled particle number of subway users can be used as reference data for an evaluation of the hazards to health caused by PM inhalation. Copyright © 2017 Elsevier Ltd. All rights reserved.

A NEW APPROACH FOR SUBWAY TUNNEL DEFORMATION MONITORING: HIGH-RESOLUTION TERRESTRIAL LASER SCANNING

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J. Li

2012-07-01

Full Text Available With the improvement of the accuracy and efficiency of laser scanning technology, high-resolution terrestrial laser scanning (TLS technology can obtain high precise points-cloud and density distribution and can be applied to high-precision deformation monitoring of subway tunnels and high-speed railway bridges and other fields. In this paper, a new approach using a points-cloud segmentation method based on vectors of neighbor points and surface fitting method based on moving least squares was proposed and applied to subway tunnel deformation monitoring in Tianjin combined with a new high-resolution terrestrial laser scanner (Riegl VZ-400. There were three main procedures. Firstly, a points-cloud consisted of several scanning was registered by linearized iterative least squares approach to improve the accuracy of registration, and several control points were acquired by total stations (TS and then adjusted. Secondly, the registered points-cloud was resampled and segmented based on vectors of neighbor points to select suitable points. Thirdly, the selected points were used to fit the subway tunnel surface with moving least squares algorithm. Then a series of parallel sections obtained from temporal series of fitting tunnel surfaces were compared to analysis the deformation. Finally, the results of the approach in z direction were compared with the fiber optical displacement sensor approach and the results in x, y directions were compared with TS respectively, and comparison results showed the accuracy errors of x, y, z directions were respectively about 1.5 mm, 2 mm, 1 mm. Therefore the new approach using high-resolution TLS can meet the demand of subway tunnel deformation monitoring.

Internal Exposure of a Seoul Subway Passenger due to Radon Inhalation: Before and After PSD Installation

Energy Technology Data Exchange (ETDEWEB)

Shin, Ji-Yong; Kim, Eun-Hee [Seoul National University, Seoul (Korea, Republic of)

2015-05-15

Radon is the major source of public exposure to natural radiation and is also known to cause lung cancer. Platform screen doors (PSD) were installed primarily for passenger's safety purposes. Radon concentration and aerosol distribution have been changed since PSD installation. In this study, we have assessed the annual effective dose of regular subway passengers, before and after PSD installation, by employing current available data on air concentration of radon in Seoul subways with aerosol size distributions taken into account. ICRP recommends that the reference value for internal dose from radon be between 1.0 and 20.0 mSv. Korean Ministry of Environment enacted the indoor radon regulation, which requires the indoor radon level should not exceed 148 Bq/m{sup 3}. Radon concentrations in Seoul subways and annual dose estimates meet the requirements.

Internal Exposure of a Seoul Subway Passenger due to Radon Inhalation: Before and After PSD Installation

International Nuclear Information System (INIS)

Shin, Ji-Yong; Kim, Eun-Hee

2015-01-01

Radon is the major source of public exposure to natural radiation and is also known to cause lung cancer. Platform screen doors (PSD) were installed primarily for passenger's safety purposes. Radon concentration and aerosol distribution have been changed since PSD installation. In this study, we have assessed the annual effective dose of regular subway passengers, before and after PSD installation, by employing current available data on air concentration of radon in Seoul subways with aerosol size distributions taken into account. ICRP recommends that the reference value for internal dose from radon be between 1.0 and 20.0 mSv. Korean Ministry of Environment enacted the indoor radon regulation, which requires the indoor radon level should not exceed 148 Bq/m 3 . Radon concentrations in Seoul subways and annual dose estimates meet the requirements

Stationary centrifugal mass energy storage at the Hamburg subway; Stationaerer Schwungmassen-Energiespeicher bei der Hamburger U-Bahn

Energy Technology Data Exchange (ETDEWEB)

Steinhorst, F. [Hamburger Hochbahn AG, Hamburg (Germany). Abt. Energieanlagen; Jonassen, I.; Peters, A. [Hamburger Hochbahn AG, Hamburg (Germany). Fachbereich Energieversorgung

2008-07-01

A stationary energy storage is to be used as a model in a substation of the Hamburg subway network with a view to the environmentally compatible and technically proper use of the brake energy available in electrified local public transport systems. A further question to be reviewed is whether the use of other energy storages in the subway network is a reasonable solution. (orig.)

Choosing TBM for Tabriz Subway using Multi Criteria Method

DEFF Research Database (Denmark)

Edalat, Kamaladdin; Vahdatirad, Mohammadjavad; Ghodrat, Hadi

2010-01-01

in diameter and in other words becoming more difficult to realize. Tabriz-one of the big cities in northern west of Iran has four subway lines which are under con-struction or investigation. The phase1 design of Tabriz urban railway line 2 (TURL2) has completely been done. Method statement of this line...

Hydrochemistry of urban groundwater, Seoul, Korea: the impact of subway tunnels on groundwater quality.

Science.gov (United States)

Chae, Gi-Tak; Yun, Seong-Taek; Choi, Byoung-Young; Yu, Soon-Young; Jo, Ho-Young; Mayer, Bernhard; Kim, Yun-Jong; Lee, Jin-Yong

2008-10-23

Hydrogeologic and hydrochemical data for subway tunnel seepage waters in Seoul (Republic of Korea) were examined to understand the effect of underground tunnels on the degradation of urban groundwater. A very large quantity of groundwater (up to 63 million m3 year(-1)) is discharged into subway tunnels with a total length of 287 km, resulting in a significant drop of the local groundwater table and the abandonment of groundwater wells. For the tunnel seepage water samples (n = 72) collected from 43 subway stations, at least one parameter among pathogenic microbes (total coliform, heterotrophic bacteria), dissolved Mn and Fe, NH4+, NO3(-), turbidity, and color exceeded the Korean Drinking Water Standards. Locally, tunnel seepage water was enriched in dissolved Mn (avg. 0.70 mg L(-1), max. 5.58 mg L(-1)), in addition to dissolved Fe, NH4+, and pathogenic microbes, likely due to significant inflow of sewage water from broken or leaking sewer pipes. Geochemical modeling of redox reactions was conducted to simulate the characteristic hydrochemistry of subway tunnel seepage. The results show that variations in the reducing conditions occur in urban groundwater, dependent upon the amount of organic matter-rich municipal sewage contaminating the aquifer. The organic matter facilitates the reduction and dissolution of Mn- and Fe-bearing solids in aquifers and/or tunnel construction materials, resulting in the successive increase of dissolved Mn and Fe. The present study clearly demonstrates that locally significant deterioration of urban groundwater is caused by a series of interlinked hydrogeologic and hydrochemical changes induced by underground tunnels.

A risk-based method for planning of bus–subway corridor evacuation under hybrid uncertainties

International Nuclear Information System (INIS)

Lv, Y.; Yan, X.D.; Sun, W.; Gao, Z.Y.

2015-01-01

Emergencies involved in a bus–subway corridor system are associated with many processes and factors with social and economic implications. These processes and factors and their interactions are related to a variety of uncertainties. In this study, an interval chance-constrained integer programming (EICI) method is developed in response to such challenges for bus–subway corridor based evacuation planning. The method couples a chance-constrained programming with an interval integer programming model framework. It can thus deal with interval uncertainties that cannot be quantified with specified probability distribution functions. Meanwhile, it can also reflect stochastic features of traffic flow capacity, and thereby help examine the related violation risk of constraint. The EICI method is applied to a subway incident based evacuation case study. It is solved through an interactive algorithm that does not lead to more complicated intermediate submodels and has a relatively low computational requirement. A number of decision alternatives could be directly generated based on results from the EICI method. It is indicated that the solutions cannot only help decision makers identify desired population evacuation and vehicle dispatch schemes under hybrid uncertainties, but also provide bases for in-depth analyses of tradeoffs among evacuation plans, total evacuation time, and constraint-violation risks. - Highlights: • An inexact model is developed for the bus–subway corridor evacuation management. • It tackles stochastic and interval uncertainties in an integer programming problem. • It can examine violation risk of the roadway flow capacity related constraint. • It will help identify evacuation schemes under hybrid uncertainties

Embedding human annoyance rate models in wireless smart sensors for assessing the influence of subway train-induced ambient vibration

Science.gov (United States)

Sun, Ke; Zhang, Wei; Ding, Huaping; Kim, Robin E.; Spencer, Billie F., Jr.

2016-10-01

The operation of subway trains induces ambient vibrations, which may cause annoyance and other adverse effects on humans, eventually leading to physical, physiological, and psychological problems. In this paper, the human annoyance rate (HAR) models, used to assess the human comfort under the subway train-induced ambient vibrations, were deduced and the calibration curves for 5 typical use circumstances were addressed. An autonomous measurement system, based on the Imote2, wireless smart sensor (WSS) platform, plus the SHM-H, high-sensitivity accelerometer board, was developed for the HAR assessment. The calibration curves were digitized and embedded in the computational core of the WSS unit. Experimental validation was conducted, using the developed system on a large underground reinforced concrete frame structure adjoining the subway station. The ambient acceleration of both basement floors was measured; the embedded computation was implemented and the HAR assessment results were wirelessly transmitted to the central server, all by the WSS unit. The HAR distributions of the testing areas were identified, and the extent to which both basements will be influenced by the close-up subway-train’s operation, in term of the 5 typical use circumstances, were quantitatively assessed. The potential of the WSS-based autonomous system for the fast environment impact assessment of the subway train-induced ambient vibration was well demonstrated.

Continuously deformation monitoring of subway tunnel based on terrestrial point clouds

NARCIS (Netherlands)

Kang, Z.; Tuo, L.; Zlatanova, S.

2012-01-01

The deformation monitoring of subway tunnel is of extraordinary necessity. Therefore, a method for deformation monitoring based on terrestrial point clouds is proposed in this paper. First, the traditional adjacent stations registration is replaced by sectioncontrolled registration, so that the

Modification of the gravity model and application to the metropolitan Seoul subway system.

Science.gov (United States)

Goh, Segun; Lee, Keumsook; Park, Jong Soo; Choi, M Y

2012-08-01

The Metropolitan Seoul Subway system is examined through the use of the gravity model. Exponents describing the power-law dependence on the time distance between stations are obtained, which reveals a universality for subway lines of the same topology. In the short (time) distance regime the number of passengers between stations does not grow with the decrease in the distance, thus deviating from the power-law behavior. It is found that such reduction in passengers is well described by the Hill function. Further, temporal fluctuations in the passenger flow data, fitted to the gravity model modified by the Hill function, are analyzed to reveal the Yule-type nature inherent in the structure of Seoul.

Identification of the sources of PM10 in a subway tunnel using positive matrix factorization.

Science.gov (United States)

Park, Duckshin; Lee, Taejeong; Hwang, Doyeon; Jung, Wonseok; Lee, Yongil; Cho, KiChul; Kim, Dongsool; Lees, Kiyoung

2014-12-01

The level of particulate matter of less than 10 μm diameter (PM10) at subway platforms can be significantly reduced by installing a platform screen-door system. However, both workers and passengers might be exposed to higher PM10 levels while the cars are within the tunnel because it is a more confined environment. This study determined the PM10 levels in a subway tunnel, and identified the sources of PM10 using elemental analysis and receptor modeling. Forty-four PM10 samples were collected in the tunnel between the Gireum and Mia stations on Line 4 in metropolitan Seoul and analyzed using inductively coupled plasma-atomic emission spectrometry and ion chromatography. The major PM10 sources were identified using positive matrix factorization (PMF). The average PM10 concentration in the tunnels was 200.8 ± 22.0 μg/m3. Elemental analysis indicated that the PM10 consisted of 40.4% inorganic species, 9.1% anions, 4.9% cations, and 45.6% other materials. Iron was the most abundant element, with an average concentration of 72.5 ± 10.4 μg/m3. The PM10 sources characterized by PMF included rail, wheel, and brake wear (59.6%), soil combustion (17.0%), secondary aerosols (10.0%), electric cable wear (8.1%), and soil and road dust (5.4%). Internal sources comprising rail, wheel, brake, and electric cable wear made the greatest contribution to the PM10 (67.7%) in tunnel air. Implications: With installation of a platform screen door, PM10 levels in subway tunnels were higher than those on platforms. Tunnel PM10 levels exceeded 150 µg/m3 of the Korean standard for subway platform. Elemental analysis of PM10 in a tunnel showed that Fe was the most abundant element. Five PM10 sources in tunnel were identified by positive matrix factorization. Railroad-related sources contributed 68% of PM10 in the subway tunnel.

Origin of polycyclic aromatic hydrocarbons and other organic pollutants in the air particles of subway stations in Barcelona.

Science.gov (United States)

van Drooge, Barend L; Prats, Raimon M; Reche, Cristina; Minguillón, MariCruz; Querol, Xavier; Grimalt, Joan O; Moreno, Teresa

2018-06-09

Underground subways transport large numbers of citizens in big cities, which must breathe air with limited ventilation. These atmospheric conditions may enhance the concentration of air pollutants from both outdoor and indoor air. The influence of ventilation conditions and maintenance activities on the concentrations of air pollutants have been studied. Particulate matter with aerodynamic diameter smaller than 2.5 μm (PM 2.5 ) in indoor air was sampled in ten platforms of nine subway stations of the metropolitan area of Barcelona in 2015 and 2016. These particles were analyzed for polycyclic aromatic hydrocarbons (PAH) and organic tracer compounds. The concentrations of PAH were in the range of the street air levels with higher PAH values in the colder period. No influence of nighttime maintenance activities was observed on the platform air quality during daytime. Source apportionment analysis using the concentrations of hopanes, nicotine and levoglucosan as molecular tracer compounds showed that 75% of the detected PAH at the platforms have an outdoor PM origin. The modern subway stations, with advanced ventilation and platform screen doors that separate the subway system from the platform, showed lowest PAH and PM concentrations. Copyright © 2018. Published by Elsevier B.V.

Route Choice in Subway Station during Morning Peak Hours: A Case of Guangzhou Subway

Directory of Open Access Journals (Sweden)

Jie Xu

2015-01-01

Full Text Available This paper is aimed at crowding phenomenon in the subway. As passengers are inclined to choose the route with minimum disutility, we put forward a route choice model which is constructed to achieve minimum objective function of feasibility for the optimal solution. Meanwhile we set passenger volume threshold values according to capacity of facilities. In the case of actual capacity exceeding the threshold, the decision node of constrained route will be selected; computing procedure about searching decision points will be presented. Then we should set rational restrictions at the decision node of the minimum utility function route to prevent too many passengers’ access to platform. Through certification, this series of methods can effectively ensure the safety of the station efficient operation.

A Study on Characteristics of Atmospheric Heavy Metals in Subway Station

Science.gov (United States)

Kim, Chun-Huem; Yoo, Dong-Chul; Kwon, Young-Min; Han, Woong-Soo; Kim, Gi-Sun; Park, Mi-Jung; Kim, Young Soon

2010-01-01

In this study, we investigated the atmospheric heavy metal concentrations in the particulate matter inside the subway stations of Seoul. In particular, we examined the correlation between the heavy metals and studied the effect of the heavy metals on cell proliferation. In six selected subway stations in Seoul, particulate matter was captured at the platforms and 11 types of heavy metals were analyzed. The results showed that the mean concentration of iron was the highest out of the heavy metals in particulate matter, followed by copper, potassium, calcium, zinc, nickel, sodium, manganese, magnesium, chromium and cadmium in that order. The correlation analysis showed that the correlations between the heavy metals was highest in the following order: (Cu vs Zn) , (Ca vs Na) , (Ca vs Mn) , (Ni vs Cr) , (Na vs Mn) , (Cr vs Cd) , (Zn vs Cd) , (Cu vs Cd) , (Ni vs Cd) , (Cu vs Ni) , (K vs Zn) , (Cu vs K) , (Cu vs Cr) , (K vs Cd) , (Zn vs Cr) , (K vs Ni) , (Zn vs Ni) , (K vs Cr) , and (Fe vs Cu) . The correlation coefficient between zinc and copper was 0.937, indicating the highest correlation. Copper, zinc, nickel, chromium and cadmium, which are generated from artificial sources in general, showed correlations with many of the other metals and the correlation coefficients were also relatively high. The effect of the heavy metals on cell proliferation was also investigated in this study. Cultured cell was exposed to 10 mg/l or 100 mg/l of iron, copper, calcium, zinc, nickel, manganese, magnesium, chromium and cadmium for 24 hours. The cell proliferation in all the heavy metal-treated groups was not inhibited at 10 mg/l of the heavy metal concentration. The only exception to this was with the cadmium-treated group which showed a strong cell proliferation inhibition. This study provides the fundamental data for the understanding of simultaneous heavy metal exposure tendency at the time of particulate matter exposure in subway stations and the identification of heavy metal

Steel dust in the New York City subway system as a source of manganese, chromium, and iron exposures for transit workers.

Science.gov (United States)

Chillrud, Steven N; Grass, David; Ross, James M; Coulibaly, Drissa; Slavkovich, Vesna; Epstein, David; Sax, Sonja N; Pederson, Dee; Johnson, David; Spengler, John D; Kinney, Patrick L; Simpson, H James; Brandt-Rauf, Paul

2005-03-01

The United States Clean Air Act Amendments of 1990 reflected increasing concern about potential effects of low-level airborne metal exposure on a wide array of illnesses. Here we summarize results demonstrating that the New York City (NYC) subway system provides an important microenvironment for metal exposures for NYC commuters and subway workers and also describe an ongoing pilot study of NYC transit workers' exposure to steel dust. Results from the TEACH (Toxic Exposure Assessment, a Columbia and Harvard) study in 1999 of 41 high-school students strongly suggest that elevated levels of iron, manganese, and chromium in personal air samples were due to exposure to steel dust in the NYC subway. Airborne concentrations of these three metals associated with fine particulate matter were observed to be more than 100 times greater in the subway environment than in home indoor or outdoor settings in NYC. While there are currently no known health effects at the airborne levels observed in the subway system, the primary aim of the ongoing pilot study is to ascertain whether the levels of these metals in the subway air affect concentrations of these metals or related metabolites in the blood or urine of exposed transit workers, who due to their job activities could plausibly have appreciably higher exposures than typical commuters. The study design involves recruitment of 40 transit workers representing a large range in expected exposures to steel dust, the collection of personal air samples of fine particulate matter, and the collection of blood and urine samples from each monitored transit worker.

Research on the Effects of Heterogeneity on Pedestrian Dynamics in Walkway of Subway Station

Directory of Open Access Journals (Sweden)

Haoling Wu

2016-01-01

Full Text Available The major objective of this paper is to study the effects of heterogeneity on pedestrian dynamics in walkway of subway station. We analyze the observed data of the selected facility and find that walking speed and occupied space were varied in the population. In reality, pedestrians are heterogeneous individuals with different attributes. However, the research on how the heterogeneity affects the pedestrian dynamics in facilities of subway stations is insufficient. The improved floor field model is therefore presented to explore the effects of heterogeneity. Pedestrians are classified into pedestrians walking in pairs, fast pedestrians, and ordinary pedestrians. For convenience, they are denoted as P-pedestrians, F-pedestrians, and O-pedestrians, respectively. The proposed model is validated under homogeneous and heterogeneous conditions. Three pedestrian compositions are simulated to analyze the effects of heterogeneity on pedestrian dynamics. The results show that P-pedestrians have negative effect and F-pedestrians have positive effect. All of the results in this paper indicate that the capacity of walkway is not a constant value. It changes with different component proportions of heterogeneous pedestrians. The heterogeneity of pedestrian has an important influence on the pedestrian dynamics in the walkway of the subway station.

Monitoring Ground Deformation of Subway Area during the Construction Based on the Method of Multi-Temporal Coherent Targets Analysis

Science.gov (United States)

Zhang, L.; Wu, J.; Zhao, J.; Yuan, M.

2018-04-01

Multi-temporal coherent targets analysis is a high-precision and high-spatial-resolution monitoring method for urban surface deformation based on Differential Synthetic Aperture Radar (DInSAR), and has been successfully applied to measure land subsidence, landslide and strain accumulation caused by fault movement and so on. In this paper, the multi-temporal coherent targets analysis is used to study the settlement of subway area during the period of subway construction. The eastern extension of Shanghai Metro Line. 2 is taking as an example to study the subway settlement during the construction period. The eastern extension of Shanghai Metro Line. 2 starts from Longyang Road and ends at Pudong airport. Its length is 29.9 kilometers from east to west and it is a key transportation line to the Pudong Airport. 17 PalSAR images during 2007 and 2010 are applied to analyze and invert the settlement of the buildings nearby the subway based on the multi-temporal coherent targets analysis. But there are three significant deformation areas nearby the Line 2 between 2007 and 2010, with maximum subsidence rate up to 30 mm/y in LOS. The settlement near the Longyang Road station and Chuansha Town are both caused by newly construction and city expansion. The deformation of the coastal dikes suffer from heavy settlement and the rate is up to -30 mm/y. In general, the area close to the subway line is relatively stable during the construction period.

Marketingové strategie řetězce Subway

OpenAIRE

Nguyen, Huu Tung

2015-01-01

This Bachelor's Thesis examines the marketing strategy of the SUBWAY restaurant chain, its market positioning, segmentation and targeting strategies and comparison between national and local marketing tactics. The aim of the Bachelor's Thesis is to make suggestions beneficial to improvements in brand awareness and growth of the company. Thesis is divided into two sections of theoretical part and practical part. In the theoretical part of the Bachelor's thesis discusses about marketing basis, ...

Multi-approach analysis of maximum riverbed scour depth above subway tunnel

Directory of Open Access Journals (Sweden)

Jun Chen

2010-12-01

Full Text Available When subway tunnels are routed underneath rivers, riverbed scour may expose the structure, with potentially severe consequences. Thus, it is important to identify the maximum scour depth to ensure that the designed buried depth is adequate. There are a range of methods that may be applied to this problem, including the fluvial process analysis method, geological structure analysis method, scour formula method, scour model experiment method, and numerical simulation method. However, the application ranges and forecasting precision of these methods vary considerably. In order to quantitatively analyze the characteristics of the different methods, a subway tunnel passing underneath a river was selected, and the aforementioned five methods were used to forecast the maximum scour depth. The fluvial process analysis method was used to characterize the river regime and evolution trend, which were the baseline for examination of the scour depth of the riverbed. The results obtained from the scour model experiment and the numerical simulation methods are reliable; these two methods are suitable for application to tunnel projects passing underneath rivers. The scour formula method was less accurate than the scour model experiment method; it is suitable for application to lower risk projects such as pipelines. The results of the geological structure analysis had low precision; the method is suitable for use as a secondary method to assist other research methods. To forecast the maximum scour depth of the riverbed above the subway tunnel, a combination of methods is suggested, and the appropriate analysis method should be chosen with respect to the local conditions.

Characterization of aerosol particles from Buenos Aires City and its subway system: PIXE and SEM/EDX

International Nuclear Information System (INIS)

Murruni, L. G.; Debray, M. E.; Minsky, D.; Kreiner, A. J.; Burlon, A.; Davidson, M.; Davidson, J.; Ozafran, M.; Vazquez, M. E.; Rosenbusch, M.; Ulke, A. G.; Solanes, V.

2007-01-01

This study analyzes total suspended particle (TSP) samples collected at two sites of Buenos Aires City (34S, 58W). One site (San Martin) placed 17 km from city center, and the other one at an underground subway station (Diagonal Norte) in downtown Buenos Aires. In both cases, gravimetric analysis has been performed, while elemental analysis using PIXE has been only carried out in the first case. To the best our knowledge, this is the first airborne particle measurement perform at a Buenos Aires underground subway station

Implications for visually stimulating advertisements on NYC subway platforms.

Science.gov (United States)

Fullwood, M Dottington; Basch, Corey H; LeBlanc, Michael

2016-03-12

Despite the fact that the New York City (NYC) Metropolitan Transportation Authority (MTA) no longer advertises tobacco products, there is no ban on ads for alcohol. The purpose of this pilot study was to evaluate the frequency of alcohol-related advertising content on the platforms of two populated subway lines in NYC. Advertisements were evaluated on one subway line (the green line) that runs through Bronx and Manhattan in NYC. In the stations included in the study, the total number of advertisements were tallied and classified according to the type of advertisement. When an advertisement for alcohol was identified, it was determined whether the ad was for an alcoholic beverage, or it if was for a different product but exhibited an alcoholic beverage in some way. A total of 26 advertisements were identified which marketed an alcohol product. An additional 24 ads were noted for marketing another product or service whereby, alcohol was depicted as being consumed. There was a statistically significant difference in ads between the different lines t (20.04)=7.62, padvertisements have, focus could shift to health promoting products, versus those that are deleterious.

Unhealthful Food-and-Beverage Advertising in Subway Stations: Targeted Marketing, Vulnerable Groups, Dietary Intake, and Poor Health.

Science.gov (United States)

Lucan, Sean C; Maroko, Andrew R; Sanon, Omar C; Schechter, Clyde B

2017-04-01

Unhealthful food-and-beverage advertising often targets vulnerable groups. The extent of such advertising in subway stations has not been reported and it is not clear how ad placement may relate to subway ridership or community demographics, or what the implications might be for diets and diet-related health in surrounding communities. Riding all subway lines (n = 7) in the Bronx, NY, USA, investigators systematically assessed all print ads (n = 1586) in all stations (n = 68) in 2012. Data about subway ridership came from the Metropolitan Transportation Authority. Demographic data on surrounding residential areas came from the U.S. Census Bureau. Data on dietary intake and diet-related conditions came from a city health-department survey. There were no ads promoting "more-healthful" food-or-beverage items (i.e., fruits, vegetables, whole grains, nuts, water or milk). There were many ads for "less-healthful" items (e.g., candies, chips, sugary cereals, frozen pizzas, "energy" drinks, coffee confections, hard alcohol, and beer). Ad placement did not relate to the number of riders entering at stations. Instead, exposure to food-or-beverage ads generally, and to "less-healthful" ads particularly (specifically ads in Spanish, directed at youth, and/or featuring minorities), was directly correlated with poverty, lower high-school graduation rates, higher percentages of Hispanics, and/or higher percentages of children in surrounding residential areas. Correlations were robust to sensitivity analyses. Additional analyses suggested correlations between ad exposures and sugary-drink consumption, fruit-and-vegetable intake, and diabetes, hypertension, and high-cholesterol rates. Subway-station ads for "less-healthful" items were located disproportionately in areas home to vulnerable populations facing diet and diet-related-health challenges. The fact that uneven ad placement did not relate to total rider counts suggests ads were not directed at the largest

Temporal and spatial patterns of suicides in Stockholm's subway stations.

Science.gov (United States)

Uittenbogaard, Adriaan; Ceccato, Vania

2015-08-01

This paper investigates the potential temporal and spatial variations of suicides in subway stations in Stockholm, Sweden. The study also assesses whether the variation in suicide rates is related to the station environments by controlling for each station's location and a number of contextual factors using regression models and geographical information systems (GIS). Data on accidents are used as references for the analysis of suicides. Findings show that suicides tend to occur during the day and in the spring. They are concentrated in the main transportation hubs but, interestingly, during off-peak hours. However, the highest rates of suicides per passenger are found in Stockholm's subway stations located in the Southern outskirts. More than half of the variation in suicide rates is associated with stations that have walls between the two sides of the platform but still allow some visibility from passers-by. The surrounding environment and socioeconomic context show little effect on suicide rates, but stations embedded in areas with high drug-related crime rates tend to show higher suicide rates. Copyright © 2015 Elsevier Ltd. All rights reserved.

Transmission characteristics of Bessel-Gaussian vortex beams propagating along both longitudinal and transverse directions in a subway tunnel

Science.gov (United States)

Wang, Xiaohui; Song, Yingxiong

2018-02-01

By exploiting the non-Kolmogorov model and Rytov approximation theory, a propagation model of Bessel-Gaussian vortex beams (BGVB) propagating in a subway tunnel is derived. Based on the propagation model, a model of orbital angular momentum (OAM) mode probability distribution is established to evaluate the propagation performance when the beam propagates along both longitudinal and transverse directions in the subway tunnel. By numerical simulations and experimental verifications, the influences of the various parameters of BGVB and turbulence on the OAM mode probability distribution are evaluated, and the results of simulations are consistent with the experimental statistics. The results verify that the middle area of turbulence is more beneficial for the vortex beam propagation than the edge; when the BGVB propagates along the longitudinal direction in the subway tunnel, the effects of turbulence on the OAM mode probability distribution can be decreased by selecting a larger anisotropy parameter, smaller coherence length, larger non-Kolmogorov power spectrum coefficient, smaller topological charge number, deeper subway tunnel, lower train speed, and longer wavelength. When the BGVB propagates along the transverse direction, the influences can be also mitigated by adopting a larger topological charge number, less non-Kolmogorov power spectrum coefficient, smaller refractive structure index, shorter wavelength, and shorter propagation distance.

Analysis of economic feasibility of opening a franchise Subway in Crimea

OpenAIRE

Tsoy, Nataly

2014-01-01

In article analysis the state of the modern fast-food market in Russian Federation. The author observes main trends in this area, the competitiveness of the different regions of the country. The special attention is given to the proposal of opening Subway franchise in the Crimea

Major depressive disorder, panic disorder, and post-traumatic stress disorder in Korean subway drivers.

Science.gov (United States)

Kim, Hyoung-Ryoul; Yim, Hyeon Woo; Jo, Sun-Jin; Choi, Bongkyoo; Jeong, Seung Hee; Lee, Kang Sook; Park, Jong-Ik; Chang, Sung Man

2013-05-01

The purposes of this study are to investigate the prevalence of major depressive disorder, panic disorder, and post-traumatic stress disorder (PTSD) in Korean subway drivers, and find the association between these disorders and the drivers' person-under-train (PUT) experiences. A total of 826 subway drivers who participated in a cross-sectional work and health survey were included for this study. The Korean version of the Composite International Diagnostic Interview 2.1 was applied to assess major depressive disorder, panic disorder, and PTSD. The date of PUT, whether victim died, and how many PUTs the drivers experienced were asked using a structured questionnaire. The standardized prevalence ratios (SPRs) for lifetime prevalence of panic disorder and PTSD in subway drivers were 13.3 (95 % confidence interval [CI] 6.6-22.4) and 2.1 (95 % CI 1.1-3.4), respectively. In lifetime prevalence, after adjusting for age, education, income, and working career, the drivers who experienced PUT had significantly higher risks for panic disorder (odds ratio [OR] = 4.2, 95 % CI 1.2-16.6) and PTSD (OR = 4.4, 95 % CI 1.3-16.4). In 1-year prevalence, the drivers who experienced PUT had a significantly higher risk for PTSD (OR = 11.7, 95 % CI 1.9-225.8). There was no significant value of SPR and OR in major depressive disorder. This study suggests that Korean subway drivers are at higher risk for panic disorder and PTSD compared to the general population, and PUT experience is associated with panic disorder and PTSD. Drivers who have experienced PUT should be treated quickly, sympathetically, and sensitively by a psychological professional and their colleagues, so they can return to work soon.

SART: an intelligent assistant system for subway control

Directory of Open Access Journals (Sweden)

P. Brézillon

2000-12-01

Full Text Available One of the main characteristics of a subway line is its large transport capacity (e.g., about 60000 travelers per hour in the Parisian subway combined with a regular transport supply. The regularity is particularly important at rush time - peak hours - when an incident can provoke important delays. Experience shows that the consequences of an incident are highly dependent on the context in which the incident occurs (e.g., peak hours or not. The decisions taken by the operators are heavily relied on the incident context, and operators often make different decisions for the same incident in different contexts. The project SART (French acronym for Support system for traffic control aims at developing an intelligent decision support system able of helping the operator in making decisions to solve an incident occurring on a line. This system relies on the notion of context. Context includes information and knowledge on the situation that do not intervene directly in the incident solving, but constrain the way in which the operator will choose a strategy at each step of the incident solving. The paper describes the SART project and highlights how Artificial Intelligence (AI techniques can contributeto knowledge acquisition and knowledge representation associated with its context of use. Particularly we discuss the notion of context and show how we use this notion to solve a real-world problem.

Radon exposure assessment for underground workers: a case of Seoul Subway Police officers in Korea.

Science.gov (United States)

Song, Myeong Han; Chang, Byung-Uck; Kim, Yongjae; Cho, Kun-Woo

2011-11-01

The objective of this study is the systematic and individual assessment of the annual effective dose due to inhaled radon for the Seoul Subway Police officers, Korea. The annual average radon concentrations were found to be in the range of 18.9-114 Bq·m(-3) in their workplaces. The total annual effective doses which may likely to be received on duty were assessed to be in the range of 0.41-1.64 mSv·y(-1). These were well below the recommended action level 10 mSv·y(-1) by ICRP. However, the effective doses were higher than subway station staff in Seoul, Korea.

Radon exposure assessment for underground workers: A case of Seoul Subway Police officers in Korea

International Nuclear Information System (INIS)

Song, M. H.; Chang, B. U.; Kim, Y.; Cho, K. W.

2011-01-01

The objective of this study is the systematic and individual assessment of the annual effective dose due to inhaled radon for the Seoul Subway Police officers, Korea. The annual average radon concentrations were found to be in the range of 18.9-114 Bq -3 in their workplaces. The total annual effective doses which may likely to be received on duty were assessed to be in the range of 0.41-1.64 mSv.y -1 . These were well below the recommended action level 10 mSv.y -1 by ICRP. However, the effective doses were higher than subway station staff in Seoul, Korea. (authors)

Vulnerability effects of passengers' intermodal transfer distance preference and subway expansion on complementary urban public transportation systems

International Nuclear Information System (INIS)

Hong, Liu; Yan, Yongze; Ouyang, Min; Tian, Hui; He, Xiaozheng

2017-01-01

The vulnerability studies on urban public transportation systems have attracted growing attentions in recent years, due to their important role in the economy development of a city and the well-beings of its citizens. This paper proposes a vulnerability model of complementary urban public transportation systems (CUPTSs) composed of bus systems and subway systems, with the consideration of passengers’ intermodal transfer distance preference (PITDP) to capture different levels of complementary strength between the two systems. Based on the model, this paper further introduces a CUPTSs-aimed vulnerability analysis method from two specific aspects: (a) vulnerability effects of different PITDP values, which facilitate the design of policies to change PITDP to reduce system vulnerability; (b) vulnerability effects of different subway expansion plans, which facilitate the vulnerability investigation of current expansion plan and the identification of the optimal expansion plan from the system vulnerability perspective. The proposed CUPTSs-aimed vulnerability analysis method is applied to investigate the complementary bus and subway systems in the city of Wuhan, China. The insights from this study are helpful to analyze other CUPTSs for valuable planning suggestions from the vulnerability perspective. - Highlights: • We model complementary urban public transportation systems’ (CUPTSs) vulnerability. • We use a PITDP metric to capture different levels of complementary relationship. • We study vulnerability under different PITDP and different subway expansion plans. • We analyze dynamic vulnerability of CUPTSs during their expansion process.

Research on Energy-Saving Operation Strategy for Multiple Trains on the Urban Subway Line

Directory of Open Access Journals (Sweden)

Jianqiang Liu

2017-12-01

Full Text Available Energy consumption for multiple trains on the urban subway line is predominantly affected by the operation strategy. This paper proposed an energy-saving operation strategy for multiple trains, which is suitable for various line conditions and complex train schedules. The model and operation modes of the strategy are illustrated in detail, aiming to take full use of regenerative braking energy in complex multi-train systems with different departure intervals and dwell times. The computing method is proposed by means of the heuristic algorithm to obtain the optimum operation curve for each train. The simulation result based on a real urban subway line is provided to verify the correctness and effectiveness of the proposed energy-saving operation strategy.

CONTINUOUSLY DEFORMATION MONITORING OF SUBWAY TUNNEL BASED ON TERRESTRIAL POINT CLOUDS

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Z. Kang

2012-07-01

Full Text Available The deformation monitoring of subway tunnel is of extraordinary necessity. Therefore, a method for deformation monitoring based on terrestrial point clouds is proposed in this paper. First, the traditional adjacent stations registration is replaced by sectioncontrolled registration, so that the common control points can be used by each station and thus the error accumulation avoided within a section. Afterwards, the central axis of the subway tunnel is determined through RANSAC (Random Sample Consensus algorithm and curve fitting. Although with very high resolution, laser points are still discrete and thus the vertical section is computed via the quadric fitting of the vicinity of interest, instead of the fitting of the whole model of a subway tunnel, which is determined by the intersection line rotated about the central axis of tunnel within a vertical plane. The extraction of the vertical section is then optimized using RANSAC for the purpose of filtering out noises. Based on the extracted vertical sections, the volume of tunnel deformation is estimated by the comparison between vertical sections extracted at the same position from different epochs of point clouds. Furthermore, the continuously extracted vertical sections are deployed to evaluate the convergent tendency of the tunnel. The proposed algorithms are verified using real datasets in terms of accuracy and computation efficiency. The experimental result of fitting accuracy analysis shows the maximum deviation between interpolated point and real point is 1.5 mm, and the minimum one is 0.1 mm; the convergent tendency of the tunnel was detected by the comparison of adjacent fitting radius. The maximum error is 6 mm, while the minimum one is 1 mm. The computation cost of vertical section abstraction is within 3 seconds/section, which proves high efficiency..

Experimental Study on the Vibration Control Effect of Long Elastic Sleeper Track in Subways

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Xiaopei Cai

2018-01-01

Full Text Available The vibration effect of urban rail transit has gained attention from both academia and the industry sector. Long Elastic Sleeper Track (LEST is a new structure for vibration reduction which has recently been designed and applied to Chinese subways. However, little research has been devoted to its vibration reduction effect. In this study, field tests were conducted during peak transit hours on Beijing Subway Line 15 to examine the vibration reduction effects of the common ballastless track and LEST on both straight and curved sections. The results demonstrate that although LEST increases the wheel-rail vertical forces, rail vertical displacements, and rail accelerations to some extent, these effects do not threaten subway operational safety, and vibrations of track bed and tunnel wall are positively mitigated. LEST has an obvious vibration reduction effect at frequencies above 40 Hz. In straight track, the vibration of bottom of the tunnel wall measured in one-third octave bands is reduced by 10.52 dB, while the vibration at point on the tunnel wall at 1.5 m height is reduced by 9.60 dB. For the curved track, the vibrations at those two points are reduced by 9.35 dB and 8.44 dB, respectively. This indicates that LEST reduces vibrations slightly more for the straight track than for the curved track.

Automatic crack detection and classification method for subway tunnel safety monitoring.

Science.gov (United States)

Zhang, Wenyu; Zhang, Zhenjiang; Qi, Dapeng; Liu, Yun

2014-10-16

Cracks are an important indicator reflecting the safety status of infrastructures. This paper presents an automatic crack detection and classification methodology for subway tunnel safety monitoring. With the application of high-speed complementary metal-oxide-semiconductor (CMOS) industrial cameras, the tunnel surface can be captured and stored in digital images. In a next step, the local dark regions with potential crack defects are segmented from the original gray-scale images by utilizing morphological image processing techniques and thresholding operations. In the feature extraction process, we present a distance histogram based shape descriptor that effectively describes the spatial shape difference between cracks and other irrelevant objects. Along with other features, the classification results successfully remove over 90% misidentified objects. Also, compared with the original gray-scale images, over 90% of the crack length is preserved in the last output binary images. The proposed approach was tested on the safety monitoring for Beijing Subway Line 1. The experimental results revealed the rules of parameter settings and also proved that the proposed approach is effective and efficient for automatic crack detection and classification.

Automatic Crack Detection and Classification Method for Subway Tunnel Safety Monitoring

Directory of Open Access Journals (Sweden)

Wenyu Zhang

2014-10-01

Full Text Available Cracks are an important indicator reflecting the safety status of infrastructures. This paper presents an automatic crack detection and classification methodology for subway tunnel safety monitoring. With the application of high-speed complementary metal-oxide-semiconductor (CMOS industrial cameras, the tunnel surface can be captured and stored in digital images. In a next step, the local dark regions with potential crack defects are segmented from the original gray-scale images by utilizing morphological image processing techniques and thresholding operations. In the feature extraction process, we present a distance histogram based shape descriptor that effectively describes the spatial shape difference between cracks and other irrelevant objects. Along with other features, the classification results successfully remove over 90% misidentified objects. Also, compared with the original gray-scale images, over 90% of the crack length is preserved in the last output binary images. The proposed approach was tested on the safety monitoring for Beijing Subway Line 1. The experimental results revealed the rules of parameter settings and also proved that the proposed approach is effective and efficient for automatic crack detection and classification.

Evaluation of the air quality benefits of the subway system in São Paulo, Brazil.

Science.gov (United States)

Silva, Cacilda Bastos Pereira da; Saldiva, Paulo Hilário Nascimento; Amato-Lourenço, Luis Fernando; Rodrigues-Silva, Fernando; Miraglia, Simone Georges El Khouri

2012-06-30

Air pollution is a severe problem in major urban areas due to increasing numbers of vehicles, reduced road capacity and few investments in public transportation, especially in developing countries. Public transportation has a special role in avoiding congestion and consequent environmental and health impacts but is considered expensive. The objective of this paper was to analyze the benefits of the São Paulo subway in terms of the air pollution in the city through strikes events, analyzing both the health outcomes and the related economic burden. For the strike events, increases in air pollutant concentrations during the strike day was observed when compared to a similar day in terms of day of the week and meteorological conditions. Increases in mortality were also observed and the associated economic burden calculated. Despite the elevated construction and operation costs of the subway, when environment and social values are considered, cost-benefit analysis results would indicate a worthwhile investment. The consideration of these aspects is essential to sustainable transportation analyses, and in the case of the São Paulo subway, our analysis clearly demonstrated the important role of this system in the city's environmental, social and economic attributes. Copyright © 2012 Elsevier Ltd. All rights reserved.

Genotoxic effects and oxidative stress induced by organic extracts of particulate matter(PM 10)collected from a subway tunnel in Seoul, Korea.

Science.gov (United States)

Jung, Mi Hyun; Kim, Ha Ryong; Park, Yong Joo; Park, Duck Shin; Chung, Kyu Hyuck; Oh, Seung Min

2012-12-12

Particulate matter (PM) has become an important health risk factor in our society. PM can easily deposit in the bronchi and lungs, causing diverse diseases such as respiratory infections, lung cancers and cardiovascular diseases. In recent days, more and more toxicological studies have been dealing with air particles in distinctive areas including industrial areas, transportation sites, or indoors. Studies on subway PM in particular, have been recognizing PM as an important health risk factor because many people use subways as a major mode of public transportation (4 million people a day in Korea). The main aim of the present study was to evaluate the genotoxic effects of organic extract (OE) of subway PM10 and potential attribution of PAHs to these effects. Particles were collected in the subway tunnel at Kil-eum station(Line 4) for one month and then extracted with Dichloromethane (DCM). Chinese Hamster Ovary cells(CHO-K1) and human normal bronchial cells (BEAS-2B) were exposed to OE, and MN and Comet assays were conducted to analyze the genotoxicity. The results showed that OE increased DNA or chromosome damages in both cell lines. In the modified Comet assay and MN assay with free radical scavengers, we confirmed that the genotoxic effect of OE was partially due to the oxidative damage on DNA. DCFHD Aassay also indicated that OE induced ROS generation in BEAS-2B cells. PAHs [benzo(a)anthracene,benzo(k)fluoranthrene, etc.], the most well-known carcinogens in polluted air, were detected in Kil-eum PM10. In conclusion, our findings confirmed that OE of subway PM10 has genotoxic effects on normal human lung cells, and oxidative stress could be one of the major mechanisms of these genotoxic effects.In addition, some genotoxic and carcinogenic PAHs were detected in OE by GC/MS/MS, even though PAHs level was not enough to increase CYP1A1 gene. Therefore, we suggest that additive or synergistic effects by unidentified chemicals as well as PAHs contained in OE of subway

Assessment of the noise annoyance among subway train conductors in Tehran, Iran.

Science.gov (United States)

Hamidi, Mansoureh; Kavousi, Amir; Zaheri, Somayeh; Hamadani, Abolfazl; Mirkazemi, Roksana

2014-01-01

Subway transportation system is a new phenomenon in Iran. Noise annoyance interferes with the individual's task performance, and the required alertness in the driving of subway trains. This is the first study conducted to measure the level of noise and noise annoyance among conductors of subway organization in Tehran, Iran. This cross sectional study was conducted among 167 randomly selected train conductors. Information related to noise annoyance was collected by using a self-administered questionnaire. The dosimetry and sound metering was done for the conductors and inside the cabins. There were 41 sound metering measuring samples inside the conductors' cabin, and there were 12 samples of conductors' noise exposure. The results of sound level meter showed that the mean Leq was 73.0 dBA ± 8.7 dBA and the dosimetry mean measured Leq was 82.1 dBA ± 6.8 dBA. 80% of conductors were very annoyed/annoyed by noise in their work place. 53.9% of conductors reported that noise affected their work performance and 63.5% reported that noise causes that they lose their concentration. The noise related to movement of train wheels on rail was reported as the worst by 83.2% followed by the noise of brakes (74.3%) and the ventilation noise (71.9%). 56.9% of conductors reported that they are suffering from sleeplessness, 40.1% from tinnitus and 80.2% feeling fatigue and sleepy. The study results showed the high level of noise and noise annoyance among train conductors and the poor health outcome of their exposure to this level of noise.

Empirical approach for real-time estimation of air flow rates in a subway station

OpenAIRE

Di Perna, Costanzo; Carbonari, Alessandro; Ansuini, Roberta; Casals Casanova, Miquel

2014-01-01

The EU-funded project called SEAM4US (Sustainable Energy mAnageMent for Underground Stations) is targeted to define advanced control systems for cost-effective management of subway stations, which will be applied to the pilot Peer Reviewed

Raman lidar for remote control explosives in the subway

Science.gov (United States)

Grishkanich, Aleksandr; Redka, Dmitriy; Vasiliev, Sergey; Tishkov, Victor; Zhevlakov, Aleksandr

2017-10-01

Laser sensing can serve as a highly effective method of searching and monitoring of explosives in the subway. The first method is essence consists in definition the explosives concentration by excitation and registration ramans shifts at wavelength of λ = 0.261 - 0.532 μm at laser sounding. Preliminary results of investigation show the real possibility to register of 2,4,6-trinitrophenylmethylnitramine with concentration on surface at level of 108÷109 cm-3 on a safe distance 50 m from the object.

Constructing a generalized network design model to study air distribution in ventilation networks in subway with a single-track tunnel

Science.gov (United States)

Lugin, IV

2018-03-01

In focus are the features of construction of the generalized design model for the network method to study air distribution in ventilation system in subway with the single-track tunnel. The generalizations, assumptions and simplifications included in the model are specified. The air distribution is calculated with regard to the influence of topology and air resistances of the ventilation network sections. The author studies two variants of the subway line: half-open and closed with dead end on the both sides. It is found that the total air exchange at a subway station depends on the station location within the line. The operating mode of fans remains unaltered in this case. The article shows that elimination of air leakage in the station ventilation room allows an increase in the air flow rate by 7–8% at the same energy consumption by fans. The influence of the stop of a train in the tunnel on the air distribution is illustrated.

The Improvement on the Xinjiekou Subway Transfer Channel of Nanjing

Science.gov (United States)

Xu, X. D.; Zheng, C. J.

The subway, which is an effective way to alleviate the traffic congestion, has gradually been constructed in many cities. With the completion of the construction, the transfer station will become the factor that affects the efficiency of the whole transport network. Based on investigation and analysis of the present situation of the passenger flow, the essay will make a prediction with the multiple linear regression and put forward two kinds of transfer channel improvement schemes for xinjiekou transfer station.

Design and evaluation of a suspension seat to reduce vibration exposure of subway operators: a case study.

Science.gov (United States)

Marcotte, Pierre; Beaugrand, Sylvie; Boutin, Jérôme; Larue, Christian

2010-01-01

Subway operators have complained about discomfort caused by whole-body vibration. To address this problem, a suspension seat with extensive ergonomic features has been adapted to the confined space of the subway operator cab. The suspension was modified from an existing suspension in order to reduce the dominant frequency of the subway vertical vibration (2.4 Hz). The suspension seat has been extensively tested on a vertical hydraulic shaker. These tests have shown that the SEAT value was lower for a higher vibration level, for higher subject weight, and for the suspension adjusted at median height. The seat also produces a lower SEAT value when there was a predominance of the 6 Hz vibration component. The horizontal seat adjustments had no influence on the suspension SEAT value. Removing the suspension damper also decreases the SEAT value for all the tested configurations. The final version of the suspension seat prototype was validated during normal subway operation with 19 different operators having weight in the 5th, 50th and 95th percentile of the operator population. Accelerations were measured with triaxial accelerometers at the seat cushion, above the suspension and on the floor. In addition to the vibration measurements, each operator was asked about his perceived discomfort from vibration exposure. Globally, the suspension seat attenuated the vertical vibration (SEAT values from 0.86 to 0.99), but discomfort due to amplification of the 2.4 Hz component occurred when the suspension height was adjusted at the minimum, even when the global weighted acceleration was lower (SEAT value < 1). These results suggest that in order to reduce the discomfort caused by whole-body vibration, the transmissibility of the seat should also be considered, in particular when there is a dominant frequency in the vibration spectra.

Music as Transitional Object and Practice: Children's Spontaneous Musical Behaviors in the Subway

Science.gov (United States)

Custodero, Lori A.; Calì, Claudia; Diaz-Donoso, Adriana

2016-01-01

This study looks at children's music making in a public setting designed for society writ large. Although known to most children in the city, the subway presents a unique environment, both structurally predictable yet sonically dynamic; it is in continuous transition. Adopting Winnicott's psychoanalytical perspective, we make a case for viewing…

Application of computational fluid dynamics and pedestrian-behavior simulations to the design of task-ambient air-conditioning systems of a subway station

Energy Technology Data Exchange (ETDEWEB)

Fukuyo, Kazuhiro [Graduate School of Innovation and Technology Management, Faculty of Engineering, Yamaguchi University, Tokiwadai 2-16-1, Ube, Yamaguchi 755-8611 (Japan)

2006-04-15

The effects of task-ambient (TA) air-conditioning systems on the air-conditioning loads in a subway station and the thermal comfort of passengers were studied using computational fluid dynamics (CFD) and pedestrian-behavior simulations. The pedestrian-behavior model was applied to a standard subway station. Task areas were set up to match with crowdedness as predicted by the pedestrian-behavior simulations. Subsequently, a variety of TA air-conditioning systems were designed to selectively control the microclimate of the task areas. Their effects on the thermal environment in the station in winter were predicted by CFD. The results were compared with those of a conventional air-conditioning system and evaluated in relation to the thermal comfort of subway users and the air-conditioning loads. The comparison showed that TA air-conditioning systems improved thermal comfort and decreased air-conditioning loads. (author)

Building damage related to Amsterdam subway : Comparison of traditional monitoring with satellite monitoring results

NARCIS (Netherlands)

Korff, M.; Maccabiani, J

2017-01-01

This paper describes the evaluation of the monitoring data obtained from the construction of the North/South Line, a new subway line crossing the historic center of Amsterdam. During construction of the line (2003-2014), building deformations were monitored with Robotic Total Stations and with

Marketingová strategie franchisingového řetězce Subway

OpenAIRE

Vostrý, Filip

2011-01-01

The aim of this work is to theoretically describe the functioning of marketing and franchising in all its aspects and with each other. On the particular example of SUBWAY chain I discovered weaknesses in terms of marketing and then tried to eliminate them and to propose some helpful changes. Practical part is based both on personal knowledge and information from owners and managers of several restaurants in Prague and Brno.

Environmental trade-offs of tunnels vs cut-and-cover subways

Science.gov (United States)

Walton, M.

1978-01-01

Heavy construction projects in cities entail two kinds of cost - internal cost, which can be defined in terms of payments from one set of parties to another, and external cost, which is the cost borne by the community at large as the result of disutilities entailed in construction and operation. Environmental trade-offs involve external costs, which are commonly difficult to measure. Cut-and-cover subway construction probably entails higher external and internal cost than deep tunnel construction in many urban geological environments, but uncertainty concerning the costs and environmental trade-offs of tunneling leads to limited and timid use of tunneling by American designers. Thus uncertainty becomes a major trade-off which works against tunneling. The reverse is true in Sweden after nearly 30 years of subway construction. Econometric methods for measuring external costs exist in principle, but are limited in application. Economic theory based on market pressure does not address the real problem of urban environmental trade-offs. Nevertheless, the problem of uncertainty can be addressed by comparative studies of estimated and as-built costs of cut-and-cover vs tunnel projects and a review of environmental issues associated with such construction. Such a study would benefit the underground construction industry and the design of transportation systems. It would also help solve an aspect of the urban problem. ?? 1978.

DISTURBANCES IN THE POWER SUPPLY NETWORK OF BUCHAREST SUBWAY SYSTEM (PART 1

Directory of Open Access Journals (Sweden)

Alexandru Ionuț CHIUȚĂ

2011-05-01

Full Text Available In the present study it is exposed the problem of disturbances in the main power supply of Bucharest Subway (underground system, the cause and their action, as well as the measures taken to limit the disturbances produced. All this is reflected in the measurements made using oscilloscope Fluke installed at the dispatch point, following to be then processed.

DHS Office of Health Affairs Chemical Defense Program Analyzes Subway Safety Against Chemical Terrorist Threats

OpenAIRE

Center for Homeland Defense and Security

2012-01-01

Center for Homeland Defense and Security, OUT OF THE CLASSROOM In an article for the journal Domestic Preparedness, Joselito Ignacio examines how to protect subway riders from chemical attacks. Ignacio graduated from the Center for Homeland Defense and Security in...

Research on dynamic creep strain and settlement prediction under the subway vibration loading.

Science.gov (United States)

Luo, Junhui; Miao, Linchang

2016-01-01

This research aims to explore the dynamic characteristics and settlement prediction of soft soil. Accordingly, the dynamic shear modulus formula considering the vibration frequency was utilized and the dynamic triaxial test conducted to verify the validity of the formula. Subsequently, the formula was applied to the dynamic creep strain function, with the factors influencing the improved dynamic creep strain curve of soft soil being analyzed. Meanwhile, the variation law of dynamic stress with sampling depth was obtained through the finite element simulation of subway foundation. Furthermore, the improved dynamic creep strain curve of soil layer was determined based on the dynamic stress. Thereafter, it could to estimate the long-term settlement under subway vibration loading by norms. The results revealed that the dynamic shear modulus formula is straightforward and practical in terms of its application to the vibration frequency. The values predicted using the improved dynamic creep strain formula closed to the experimental values, whilst the estimating settlement closed to the measured values obtained in the field test.

Multi-approach analysis of maximum riverbed scour depth above subway tunnel

OpenAIRE

Jun Chen; Hong-wu Tang; Zui-sen Li; Wen-hong Dai

2010-01-01

When subway tunnels are routed underneath rivers, riverbed scour may expose the structure, with potentially severe consequences. Thus, it is important to identify the maximum scour depth to ensure that the designed buried depth is adequate. There are a range of methods that may be applied to this problem, including the fluvial process analysis method, geological structure analysis method, scour formula method, scour model experiment method, and numerical simulation method. However, the applic...

The influence of subway station design on noise levels.

Science.gov (United States)

Shah, Ravi R; Suen, Jonathan J; Cellum, Ilana P; Spitzer, Jaclyn B; Lalwani, Anil K

2017-05-01

To investigate the impact of subway station design on platform noise levels. Observational. Continuous A-weighted decibel (dBA) sound levels were recorded in 20 New York City subway stations, where trains entered on either a straight track or curved track in 10 stations each. Equivalent continuous noise levels (L eq ) at various locations on the boarding platform (inbound end, midplatform, and outbound end) during train entry and exit were compared between the straight and curved stations in broadband as well as narrow one-third octave bands. Overall, curved stations trended louder than straight stations, although the difference in broadband L eq did not reach statistical significance (curve, 83.4 dBA; straight, 82.6 dBA; P = .054). Noise levels were significantly louder at the inbound end of the platform during train entry (inbound, 89.7 dBA; mid, 85.5 dBA; outbound, 78.7 dBA; P < .001) and at the outbound end during train exit (inbound, 79.7 dBA; mid, 85.3 dBA; outbound, 89.1 dBA; P < .001). Narrow band analysis showed that curved stations were significantly louder than straight stations at 100 Hz and high frequencies from 8 to 20 kHz. Peak impact levels ranged from 104 to 121 dBA. Curved stations have a different noise profile compared to straight stations and are significantly louder than straight stations at high frequencies. Designing stations with straight tracks within the platform can help reduce commuter noise exposure. NA Laryngoscope, 127:1169-1174, 2017. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

The Underground Economy: Tracking the Wider Impacts of the São Paulo Subway System

NARCIS (Netherlands)

Haddad, E.A.; Hewings, G.J.D.; Porsse, A.A.; van Leeuwen, E.S.; Vieira, R.S.

2015-01-01

Over one million workers commute daily to São Paulo City center, using different modes of transportation. The São Paulo subway network reaches 74.2. km of length and is involved in around 20% of the commuting trips by public transportation, enhancing mobility and productivity of workers. This paper

Air quality inside subway metro indoor environment worldwide: A review.

Science.gov (United States)

Xu, Bin; Hao, Jinliang

2017-10-01

The air quality in the subway metro indoor microenvironment has been of particular public concern. With specific reference to the growing demand of green transportation and sustainable development, subway metro systems have been rapidly developed worldwide in last decades. The number of metro commuters has continuously increased over recent years in metropolitan cities. In some cities, metro system has become the primary public transportation mode. Although commuters typically spend only 30-40min in metros, the air pollutants emitted from various interior components of metro system as well as air pollutants carried by ventilation supply air are significant sources of harmful air pollutants that could lead to unhealthy human exposure. Commuters' exposure to various air pollutants in metro carriages may cause perceivable health risk as reported by many environmental health studies. This review summarizes significant findings in the literature on air quality inside metro indoor environment, including pollutant concentration levels, chemical species, related sources and health risk assessment. More than 160 relevant studies performed across over 20 countries were carefully reviewed. These comprised more than 2000 individual measurement trips. Particulate matters, aromatic hydrocarbons, carbonyls and airborne bacteria have been identified as the primary air pollutants inside metro system. On this basis, future work could focus on investigating the chronic health risks of exposure to various air pollutants other than PM, and/or further developing advanced air purification unit to improve metro in-station air quality. Copyright © 2017 Elsevier Ltd. All rights reserved.

Predictive monitoring and diagnosis of periodic air pollution in a subway station.

Science.gov (United States)

Kim, YongSu; Kim, MinJung; Lim, JungJin; Kim, Jeong Tai; Yoo, ChangKyoo

2010-11-15

The purpose of this study was to develop a predictive monitoring and diagnosis system for the air pollutants in a subway system using a lifting technique with a multiway principal component analysis (MPCA) which monitors the periodic patterns of the air pollutants and diagnoses the sources of the contamination. The basic purpose of this lifting technique was to capture the multivariate and periodic characteristics of all of the indoor air samples collected during each day. These characteristics could then be used to improve the handling of strong periodic fluctuations in the air quality environment in subway systems and will allow important changes in the indoor air quality to be quickly detected. The predictive monitoring approach was applied to a real indoor air quality dataset collected by telemonitoring systems (TMS) that indicated some periodic variations in the air pollutants and multivariate relationships between the measured variables. Two monitoring models--global and seasonal--were developed to study climate change in Korea. The proposed predictive monitoring method using the lifted model resulted in fewer false alarms and missed faults due to non-stationary behavior than that were experienced with the conventional methods. This method could be used to identify the contributions of various pollution sources. Copyright © 2010 Elsevier B.V. All rights reserved.

Statistical properties of effective drought index (EDI) for Seoul, Busan, Daegu, Mokpo in South Korea

Science.gov (United States)

Park, Jong-Hyeok; Kim, Ki-Beom; Chang, Heon-Young

2014-08-01

Time series of drought indices has been considered mostly in view of temporal and spatial distributions of a drought index so far. Here we investigate the statistical properties of a daily Effective Drought Index (EDI) itself for Seoul, Busan, Daegu, Mokpo for the period of 100 years from 1913 to 2012. We have found that both in dry and wet seasons the distribution of EDI as a function of EDI follows the Gaussian function. In dry season the shape of the Gaussian function is characteristically broader than that in wet seasons. The total number of drought days during the period we have analyzed is related both to the mean value and more importantly to the standard deviation. We have also found that according to the distribution of the number of occasions where the EDI values of several consecutive days are all less than a threshold, the distribution follows the exponential distribution. The slope of the best fit becomes steeper not only as the critical EDI value becomes more negative but also as the number of consecutive days increases. The slope of the exponential distribution becomes steeper as the number of the city in which EDI is simultaneously less than a critical EDI in a row increases. Finally, we conclude by pointing out implications of our findings.

Concentration and characterization of airborne particles in Tehran's subway system.

Science.gov (United States)

Kamani, Hosein; Hoseini, Mohammad; Seyedsalehi, Mahdi; Mahdavi, Yousef; Jaafari, Jalil; Safari, Gholam Hosein

2014-06-01

Particulate matter is an important air pollutant, especially in closed environments like underground subway stations. In this study, a total of 13 elements were determined from PM10 and PM2.5 samples collected at two subway stations (Imam Khomeini and Sadeghiye) in Tehran's subway system. Sampling was conducted in April to August 2011 to measure PM concentrations in platform and adjacent outdoor air of the stations. In the Imam Khomeini station, the average concentrations of PM10 and PM2.5 were 94.4 ± 26.3 and 52.3 ± 16.5 μg m(-3) in the platform and 81.8 ± 22.2 and 35 ± 17.6 μg m(-3) in the outdoor air, respectively. In the Sadeghiye station, mean concentrations of PM10 and PM2.5 were 87.6 ± 23 and 41.3 ± 20.4 μg m(-3) in the platform and 73.9 ± 17.3 and 30 ± 15 μg m(-3), in the outdoor air, respectively. The relative contribution of elemental components in each particle fraction were accounted for 43% (PM10) and 47.7% (PM2.5) in platform of Imam Khomeini station and 15.9% (PM10) and 18.5% (PM2.5) in the outdoor air of this station. Also, at the Sadeghiye station, each fraction accounted for 31.6% (PM10) and 39.8% (PM2.5) in platform and was 11.7% (PM10) and 14.3% (PM2.5) in the outdoor. At the Imam Khomeini station, Fe was the predominant element to represent 32.4 and 36 % of the total mass of PM10 and PM2.5 in the platform and 11.5 and 13.3% in the outdoor, respectively. At the Sadeghiye station, this element represented 22.7 and 29.8% of total mass of PM10 and PM2.5 in the platform and 8.7 and 10.5% in the outdoor air, respectively. Other major crustal elements were 5.8% (PM10) and 5.3% (PM2.5) in the Imam Khomeini station platform and 2.3 and 2.4% in the outdoor air, respectively. The proportion of other minor elements was significantly lower, actually less than 7% in total samples, and V was the minor concentration in total mass of PM10 and PM2.5 in both platform stations.

Deriving Spatio-Temporal Development of Ground Subsidence Due to Subway Construction and Operation in Delta Regions with PS-InSAR Data: A Case Study in Guangzhou, China

Directory of Open Access Journals (Sweden)

Huiqiang Wang

2017-09-01

Full Text Available Subways have been an important method for relieving traffic pressures in urban areas, but ground subsidence, during construction and operation, can be a serious problem as it may affect the safety of its operation and that of the surrounding buildings. Thus, conducting long-term ground deformation monitoring and modeling for subway networks are essential. Compared with traditional geodetic methods, the Persistent Scatterer Interferometric Synthetic Aperture Radar (PS-InSAR technique offers wider coverage and denser measurements along subway lines. In this study, we mapped the surface deformation of the Guangzhou subway network with Advanced Synthetic Aperture Radar (ASAR and Phased Array Type L-band Synthetic Aperture Radar (PALSAR data using the Interferometric Point Target Analysis (IPTA technique. The results indicate that newly excavated tunnels have regional subsidence with an average rate of more than 8 mm/year, as found on Lines Two, Three, Six, and GuangFo (GF. Furthermore, we determined the spatio-temporal subsidence behavior of subways with PALSAR in delta areas using Peck’s formula and the logistic time model. We estimated the tunneling-related parameters in soft soil areas, which had not been previously explored. We examined a section of line GF, as an example, to estimate the ground settlement trough development. The results showed the maximum settlement increased from −5.2 mm to −23.6 mm and its ground loss ratio ranged from 1.5–8.7% between 13 July 2008 and 19 January 2011. In addition, we found that the tunnels in line GF will become stable after a period of about 2300 days in peak subsidence areas. The results show that the proposed approach can help explain the dynamic ground subsidence along a metro line. This study can provide references for urban subway projects in delta areas, and for the risk assessment of nearby buildings and underground pipelines along metro lines.

Chemical characterization of outdoor and subway fine (PM(2.5-1.0)) and coarse (PM(10-2.5)) particulate matter in Seoul (Korea) by computer-controlled scanning electron microscopy (CCSEM).

Science.gov (United States)

Byeon, Sang-Hoon; Willis, Robert; Peters, Thomas M

2015-02-13

Outdoor and indoor (subway) samples were collected by passive sampling in urban Seoul (Korea) and analyzed with computer-controlled scanning electron microscopy coupled with energy dispersive x-ray spectroscopy (CCSEM-EDX). Soil/road dust particles accounted for 42%-60% (by weight) of fine particulate matter larger than 1 µm (PM(2.5-1.0)) in outdoor samples and 18% of PM2.5-1.0 in subway samples. Iron-containing particles accounted for only 3%-6% in outdoor samples but 69% in subway samples. Qualitatively similar results were found for coarse particulate matter (PM(10-2.5)) with soil/road dust particles dominating outdoor samples (66%-83%) and iron-containing particles contributing most to subway PM(10-2.5) (44%). As expected, soil/road dust particles comprised a greater mass fraction of PM(10-2.5) than PM(2.5-1.0). Also as expected, the mass fraction of iron-containing particles was substantially less in PM(10-2.5) than in PM(2.5-1.0). Results of this study are consistent with known emission sources in the area and with previous studies, which showed high concentrations of iron-containing particles in the subway compared to outdoor sites. Thus, passive sampling with CCSEM-EDX offers an inexpensive means to assess PM(2.5-1.0) and PM(10-2.5) simultaneously and by composition at multiple locations.

NON-TRIVIALITY OF THE RESULTS OF MILGRAM FIELD EXPERIMENT IN MOSCOW AND NEW YORK SUBWAY

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Olga V Mitina

2017-12-01

Full Text Available Non-triviality of the results of the field experiment conducted on Stanley Milgram’s methodology in the New York and Moscow subway have been studied. The statistical significance of the difference between empirical and predicted results has been taken as the non-triviality criterion. 208 respondents (psychologists and students studying psychology were asked to predict an experimental result in dependence on an experimenter’s and subject’s gender, a subject’s age, and a city where the experiment was carried out. The obtained results have confirmed our hypothesis on non-triviality of the experiments in subways: it has been showed that there is a statistically significant difference between real behavior of subway passengers (in New York and in Moscow and predictions made by Moscow and Tashkent respondents. Practically in most cases the predicted probability that a subject gives a seat after request of experimenter (young woman or young man is much less than in reality. The structural equation modeling (SEM has been used to analyze the data by constructing the model taking account of all factors mentioned above. The model fit the experimental data well (CFI = 0.919. It has been found that predicted results depend not only on gender, age, and residence of a respondent but also on the degree of familiarity with the research. The obtained data give an important material for a further study of the role of situational (an experiment design and individual (respondent characteristics factors in predicted results; they contribute to further understanding of the problem of creation and support of non-formal social norms in various cultures and show new aspects of research carried out on experimental methodology of Stanley Milgram.

Alcohol advertising at Boston subway stations: an assessment of exposure by race and socioeconomic status.

Science.gov (United States)

Gentry, Elisabeth; Poirier, Katie; Wilkinson, Tiana; Nhean, Siphannay; Nyborn, Justin; Siegel, Michael

2011-10-01

We investigated the frequency of alcohol ads at all 113 subway and streetcar stations in Boston and the patterns of community exposure stratified by race, socioeconomic status, and age. We assessed the extent of alcohol advertising at each station in May 2009. We measured gross impressions and gross rating points (GRPs) for the entire Greater Boston population and for Boston public school student commuters. We compared the frequency of alcohol advertising between neighborhoods with differing demographics. For the Greater Boston population, alcohol advertising at subway stations generated 109 GRPs on a typical day. For Boston public school students in grades 5 to 12, alcohol advertising at stations generated 134 GRPs. Advertising at stations in low-poverty neighborhoods generated 14.1 GRPs and at stations in high-poverty areas, 63.6 GRPs. Alcohol ads reach the equivalent of every adult in the Greater Boston region and the equivalent of every 5th- to 12th-grade public school student each day. More alcohol ads were displayed in stations in neighborhoods with high poverty rates than in stations in neighborhoods with low poverty rates.

Possibilities of reduction of the on-board energy for an innovative subway

OpenAIRE

Allègre, A-L.; Barrade, P.; Delarue, P.; Bouscayrol, A.; Chattot, E.; El-Fassi, S.

2009-01-01

An innovative subway has been proposed using supercapacitors as energy source. In this paper, are presented different possibilities to reduce on-board stored energy in order to downsize the on-board energy storage subsystem. Special attention is paid to the influence of a feeding rail extension or a downward slope at the beginning of the interstation on the on-board stored energy. A map is built to facilitate the selection of the solution which leads to reduce the on-board energy.

On the calculation of air flow rates to ventilate closed-type stations in subway with the double-track tunnel

Science.gov (United States)

Kiyanitsa, LA

2018-03-01

Metro is not only the most promising kind of public transport but also an important part of infrastructure in a modern city. As a place where large groups of people gather, subway is to ensure the required air exchange at the passenger platforms of the stations. The air flow rate for airing the stations is also determined based on the required temperature, humidity and MAC of gases. The present study estimates the required air flow rate at the passenger platform of the closed-type subway station with the double-track tunnel given the standard air temperature, humidity and gas concentration, as well as based on the condition of the specified air flow feed and air changes per hour. The article proposes the scheme of air recirculation from the double-track tunnel to the station.

Assessment of the impact of dipped guideways on urban rail transit systems: Ventilation and safety requirements

Science.gov (United States)

1982-01-01

The ventilation and fire safety requirements for subway tunnels with dipped profiles between stations as compared to subway tunnels with level profiles were evaluated. This evaluation is based upon computer simulations of a train fire emergency condition. Each of the tunnel configurations evaluated was developed from characteristics that are representative of modern transit systems. The results of the study indicate that: (1) The level tunnel system required about 10% more station cooling than dipped tunnel systems in order to meet design requirements; and (2) The emergency ventilation requirements are greater with dipped tunnel systems than with level tunnel systems.

Stress state in the neighborhood of subways and pipe lines under the action of dynamic loads

International Nuclear Information System (INIS)

Alexeyeva, L.A.; Eskalieva, A.Z.; Shershnev, V.V.

2001-01-01

We consider the long underground constructions of deep and shallow types such as transport subways, mines, underground pipes etc. by the action of dynamic lads. Situated in areas of seismic activity, they are subjected to the influence of seismic waves during earthquakes and can be destroyed. Running loads inside constructions (transport for instance) affect upon toughness and stability of both subways and surrounding medium. If underground construction dispose near a day's surface, it acts also on nearby buildings. Evaluations of behavior of underground and pipes under dynamic influences in real conditions of usage are determined of stress state of constructions in the interaction with environment medium. Here underground constructions are simulated by infinitely long cylindrical cavities in utter ambience. As utter ambience the isotropic elastic medium and two-component medium of Biot are researched. Last one allows simulating saturated water oils. The elastic cylindrical shell simulates supporting of a tunnel (or pipeline). Both a tress state of construction and surrounding medium were investigated for a different contact conditions between support of tunnel and environment (rigid, slippery and viscous contacts). (author)

Preferred listening levels of mobile phone programs when considering subway interior noise

Directory of Open Access Journals (Sweden)

Jyaehyoung Yu

2016-01-01

Full Text Available Today, people listen to music loud using personal listening devices. Although a majority of studies have reported that the high volume played on these listening devices produces a latent risk of hearing problems, there is a lack of studies on "double noise exposures" such as environmental noise plus recreational noise. The present study measures the preferred listening levels of a mobile phone program with subway interior noise for 74 normal-hearing participants in five age groups (ranging from 20s to 60s. The speakers presented the subway interior noise at 73.45 dB, while each subject listened to three application programs [Digital Multimedia Broadcasting (DMB, music, game] for 30 min using a tablet personal computer with an earphone. The participants′ earphone volume levels were analyzed using a sound level meter and a 2cc coupler. Overall, the results showed that those in their 20s listened to the three programs significantly louder with DMB set at significantly higher volume levels than for the other programs. Higher volume levels were needed for middle frequency compared to the lower and higher frequencies. We concluded that any potential risk of noise-induced hearing loss for mobile phone users should be communicated when users listen regularly, although the volume level was not high enough that the users felt uncomfortable. When considering individual listening habits on mobile phones, further study to predict total accumulated environmental noise is still needed.

Preferred listening levels of mobile phone programs when considering subway interior noise.

Science.gov (United States)

Yu, Jyaehyoung; Lee, Donguk; Han, Woojae

2016-01-01

Today, people listen to music loud using personal listening devices. Although a majority of studies have reported that the high volume played on these listening devices produces a latent risk of hearing problems, there is a lack of studies on "double noise exposures" such as environmental noise plus recreational noise. The present study measures the preferred listening levels of a mobile phone program with subway interior noise for 74 normal-hearing participants in five age groups (ranging from 20s to 60s). The speakers presented the subway interior noise at 73.45 dB, while each subject listened to three application programs [Digital Multimedia Broadcasting (DMB), music, game] for 30 min using a tablet personal computer with an earphone. The participants' earphone volume levels were analyzed using a sound level meter and a 2cc coupler. Overall, the results showed that those in their 20s listened to the three programs significantly louder with DMB set at significantly higher volume levels than for the other programs. Higher volume levels were needed for middle frequency compared to the lower and higher frequencies. We concluded that any potential risk of noise-induced hearing loss for mobile phone users should be communicated when users listen regularly, although the volume level was not high enough that the users felt uncomfortable. When considering individual listening habits on mobile phones, further study to predict total accumulated environmental noise is still needed.

Automated As-Built Model Generation of Subway Tunnels from Mobile LiDAR Data

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Mostafa Arastounia

2016-09-01

Full Text Available This study proposes fully-automated methods for as-built model generation of subway tunnels employing mobile Light Detection and Ranging (LiDAR data. The employed dataset is acquired by a Velodyne HDL 32E and covers 155 m of a subway tunnel containing six million points. First, the tunnel’s main axis and cross sections are extracted. Next, a preliminary model is created by fitting an ellipse to each extracted cross section. The model is refined by employing residual analysis and Baarda’s data snooping method to eliminate outliers. The final model is then generated by applying least squares adjustment to outlier-free data. The obtained results indicate that the tunnel’s main axis and 1551 cross sections at 0.1 m intervals are successfully extracted. Cross sections have an average semi-major axis of 7.8508 m with a standard deviation of 0.2 mm and semi-minor axis of 7.7509 m with a standard deviation of 0.1 mm. The average normal distance of points from the constructed model (average absolute error is also 0.012 m. The developed algorithm is applicable to tunnels with any horizontal orientation and degree of curvature since it makes no assumptions, nor does it use any a priori knowledge regarding the tunnel’s curvature and horizontal orientation.

Rush-hour aromatic and chlorinated hydrocarbons in selected subway stations of Shanghai, China.

Science.gov (United States)

Zhang, Yanli; Li, Chunlei; Wang, Xinming; Guo, Hai; Feng, Yanli; Chen, Jianmin

2012-01-01

Air samples were collected simultaneously at platform, mezzanine and outdoor in five typical stations of subway system in Shanghai, China using stainless steel canisters and analyzed by gas chromatography-mass selective detector (GC-MSD) after cryogenic preconcentration. Benzene, toluene, ethylbenzene and xylenes (BTEX) at the platforms and mezzanines inside the stations averaged (10.3 +/- 2.1), (38.7 +/- 9.0), (19.4 +/- 10.1) and (30.0 +/- 11.1) microg/m3, respectively; while trichloroethylene (TrCE), tetrachloroethylene (TeCE) and para-dichlorobenzene (pDCB), vinyl chloride and carbon tetrachloride were the most abundant chlorinated hydrocarbons inside the stations with average levels of (3.6 +/- 1.3), (1.3 +/- 0.5), (4.1 +/- 1.1), (2.2 +/- 1.1) and (1.2 +/- 0.3) microg/m3, respectively. Mean levels of major aromatic and chlorinated hydrocarbons were higher indoor (platforms and mezzanines) than outdoor with average indoor/outdoor (I/O) ratios of 1.1-9.5, whereas no significant indoor/outdoor differences were found except for benzene and TrCE. The highly significant mutual correlations (p subway stations from indoor/outdoor air exchange and traffic emission should be their dominant source. TrCE and pDCB were mainly from indoor emission and TeCE might have both indoor emission sources and contribution from outdoor air, especially in the mezzanines.

A real-time monitoring and assessment method for calculation of total amounts of indoor air pollutants emitted in subway stations.

Science.gov (United States)

Oh, TaeSeok; Kim, MinJeong; Lim, JungJin; Kang, OnYu; Shetty, K Vidya; SankaraRao, B; Yoo, ChangKyoo; Park, Jae Hyung; Kim, Jeong Tai

2012-05-01

Subway systems are considered as main public transportation facility in developed countries. Time spent by people in indoors, such as underground spaces, subway stations, and indoor buildings, has gradually increased in the recent past. Especially, operators or old persons who stay in indoor environments more than 15 hr per day usually influenced a greater extent by indoor air pollutants. Hence, regulations on indoor air pollutants are needed to ensure good health of people. Therefore, in this study, a new cumulative calculation method for the estimation of total amounts of indoor air pollutants emitted inside the subway station is proposed by taking cumulative amounts of indoor air pollutants based on integration concept. Minimum concentration of individual air pollutants which naturally exist in indoor space is referred as base concentration of air pollutants and can be found from the data collected. After subtracting the value of base concentration from data point of each data set of indoor air pollutant, the primary quantity of emitted air pollutant is calculated. After integration is carried out with these values, adding the base concentration to the integration quantity gives the total amount of indoor air pollutant emitted. Moreover the values of new index for cumulative indoor air quality obtained for 1 day are calculated using the values of cumulative air quality index (CAI). Cumulative comprehensive indoor air quality index (CCIAI) is also proposed to compare the values of cumulative concentrations of indoor air pollutants. From the results, it is clear that the cumulative assessment approach of indoor air quality (IAQ) is useful for monitoring the values of total amounts of indoor air pollutants emitted, in case of exposure to indoor air pollutants for a long time. Also, the values of CCIAI are influenced more by the values of concentration of NO2, which is released due to the use of air conditioners and combustion of the fuel. The results obtained in

Attack in a subway by an explosive containing radioactive substance. Specificities of the taking charge and assistance organization

International Nuclear Information System (INIS)

Curet, P.M.

1999-01-01

The use of explosives with radioactive material in them during an attack in the subway obliges several specificities in the help organisation, in the taking charge of victims and in the environmental management for the broadest meaning. That is the purpose of this article. (N.C.)

Chemical Characterization of Outdoor and Subway Fine (PM2.5–1.0) and Coarse (PM10–2.5) Particulate Matter in Seoul (Korea) by Computer-Controlled Scanning Electron Microscopy (CCSEM)

Science.gov (United States)

Byeon, Sang-Hoon; Willis, Robert; Peters, Thomas M.

2015-01-01

Outdoor and indoor (subway) samples were collected by passive sampling in urban Seoul (Korea) and analyzed with computer-controlled scanning electron microscopy coupled with energy dispersive x-ray spectroscopy (CCSEM-EDX). Soil/road dust particles accounted for 42%–60% (by weight) of fine particulate matter larger than 1 µm (PM2.5–1.0) in outdoor samples and 18% of PM2.5–1.0 in subway samples. Iron-containing particles accounted for only 3%–6% in outdoor samples but 69% in subway samples. Qualitatively similar results were found for coarse particulate matter (PM10–2.5) with soil/road dust particles dominating outdoor samples (66%–83%) and iron-containing particles contributing most to subway PM10–2.5 (44%). As expected, soil/road dust particles comprised a greater mass fraction of PM10–2.5 than PM2.5–1.0. Also as expected, the mass fraction of iron-containing particles was substantially less in PM10–2.5 than in PM2.5–1.0. Results of this study are consistent with known emission sources in the area and with previous studies, which showed high concentrations of iron-containing particles in the subway compared to outdoor sites. Thus, passive sampling with CCSEM-EDX offers an inexpensive means to assess PM2.5–1.0 and PM10-2.5 simultaneously and by composition at multiple locations. PMID:25689348

Chemical Characterization of Outdoor and Subway Fine (PM2.5–1.0 and Coarse (PM10–2.5 Particulate Matter in Seoul (Korea by Computer-Controlled Scanning Electron Microscopy (CCSEM

Directory of Open Access Journals (Sweden)

Sang-Hoon Byeon

2015-02-01

Full Text Available Outdoor and indoor (subway samples were collected by passive sampling in urban Seoul (Korea and analyzed with computer-controlled scanning electron microscopy coupled with energy dispersive x-ray spectroscopy (CCSEM-EDX. Soil/road dust particles accounted for 42%–60% (by weight of fine particulate matter larger than 1 µm (PM2.5–1.0 in outdoor samples and 18% of PM2.5–1.0 in subway samples. Iron-containing particles accounted for only 3%–6% in outdoor samples but 69% in subway samples. Qualitatively similar results were found for coarse particulate matter (PM10–2.5 with soil/road dust particles dominating outdoor samples (66%–83% and iron-containing particles contributing most to subway PM10–2.5 (44%. As expected, soil/road dust particles comprised a greater mass fraction of PM10–2.5 than PM2.5–1.0. Also as expected, the mass fraction of iron-containing particles was substantially less in PM10–2.5 than in PM2.5–1.0. Results of this study are consistent with known emission sources in the area and with previous studies, which showed high concentrations of iron-containing particles in the subway compared to outdoor sites. Thus, passive sampling with CCSEM-EDX offers an inexpensive means to assess PM2.5–1.0 and PM10-2.5 simultaneously and by composition at multiple locations.

Energy-Independent Architectural Models for Residential Complex Plans through Solar Energy in Daegu Metropolitan City, South Korea

Directory of Open Access Journals (Sweden)

Sung-Yul Kim

2018-02-01

Full Text Available This study suggests energy-independent architectural models for residential complexes through the production of solar-energy-based renewable energy. Daegu Metropolitan City, South Korea, was selected as the target area for the residential complex. An optimal location in the area was selected to maximize the production of solar-energy-based renewable energy. Then, several architectural design models were developed. Next, after analyzing the energy-use patterns of each design model, economic analyses were conducted considering the profits generated from renewable-energy use. In this way, the optimum residential building model was identified. For this site, optimal solar power generation efficiency was obtained when solar panels were installed at 25° angles. Thus, the sloped roof angles were set to 25°, and the average height of the internal space of the highest floor was set to 1.8 m. Based on this model, analyses were performed regarding energy self-sufficiency improvement and economics. It was verified that connecting solar power generation capacity from a zero-energy perspective considering the consumer’s amount of power consumption was more effective than connecting maximum solar power generation capacity according to building structure. Moreover, it was verified that selecting a subsidizable solar power generation capacity according to the residential solar power facility connection can maximize operational benefits.

Pollution sources for indoor PM2.5 at the platform in subway station using a positive matrix factorization and an instrumental neutron activation analysis

Energy Technology Data Exchange (ETDEWEB)

Lim, Jong Myoung; Moon, Jong Hwa; Chung, Yong Sam [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Lee, Jin Hong [Chungnam National University, Daejeon (Korea, Republic of)

2010-05-15

Airborne particulate matters, especially the PM2.5 (aerodynamic equivalent diameter, AED, less than 2.5 )m) fraction has been important. This is because of their potential for deposition on to the human respiratory system being accompanied by many harmful trace metals (such as As, Cd, Cr, Cu, Mn, Pb, Se, and Zn). As most people spend more than 80% of their time indoors, indoor air quality (IAQ) can exert a considerable impact on the inhalation condition of toxic substances. Therefore, assessment of the absolute concentration levels and elemental composition of PM in an indoor environment such as subway station can be used as a practical barometer of IAQ. The contaminants originated from the indoor pollution sources as well as various outdoor sources are easily accumulated in indoor environment dissimilar to the outdoor. Especially, since the natural ventilation is nearly impossible in the subway station, its pollution status can be worsened under the circumstance that contaminants are constantly originated and circulated inside of station by the repetitive action of subway trains. In this study, a total of 60 PM2.5 samples were collected for 4 seasonal campaigns in 2009 with a low-volume air sampler at one subway station in Daejeon, Korea. We undertook the measurements of up to 25 elements in PM2.5 using an instrumental neutron activation analysis (INAA) and X-ray fluorescence (XRF). And inorganic ion species (SO{sub 4}{sup 2-}, NO{sub 3}{sup -}, NH{sub 4}{sup +}) also were determined by ion chromatography (IC). Next, sources at indoor/outdoor environment were identified and the contributions of each source were quantified by positive matrix factorization (PMF).

Pollution sources for indoor PM2.5 at the platform in subway station using a positive matrix factorization and an instrumental neutron activation analysis

International Nuclear Information System (INIS)

Lim, Jong Myoung; Moon, Jong Hwa; Chung, Yong Sam; Lee, Jin Hong

2010-01-01

Airborne particulate matters, especially the PM2.5 (aerodynamic equivalent diameter, AED, less than 2.5 )m) fraction has been important. This is because of their potential for deposition on to the human respiratory system being accompanied by many harmful trace metals (such as As, Cd, Cr, Cu, Mn, Pb, Se, and Zn). As most people spend more than 80% of their time indoors, indoor air quality (IAQ) can exert a considerable impact on the inhalation condition of toxic substances. Therefore, assessment of the absolute concentration levels and elemental composition of PM in an indoor environment such as subway station can be used as a practical barometer of IAQ. The contaminants originated from the indoor pollution sources as well as various outdoor sources are easily accumulated in indoor environment dissimilar to the outdoor. Especially, since the natural ventilation is nearly impossible in the subway station, its pollution status can be worsened under the circumstance that contaminants are constantly originated and circulated inside of station by the repetitive action of subway trains. In this study, a total of 60 PM2.5 samples were collected for 4 seasonal campaigns in 2009 with a low-volume air sampler at one subway station in Daejeon, Korea. We undertook the measurements of up to 25 elements in PM2.5 using an instrumental neutron activation analysis (INAA) and X-ray fluorescence (XRF). And inorganic ion species (SO 4 2- , NO 3 - , NH 4 + ) also were determined by ion chromatography (IC). Next, sources at indoor/outdoor environment were identified and the contributions of each source were quantified by positive matrix factorization (PMF).

Key techniques and risk management for the application of the Pile-Beam-Arch (PBA) excavation method: a case study of the Zhongjie subway station.

Science.gov (United States)

Guan, Yong-ping; Zhao, Wen; Li, Shen-gang; Zhang, Guo-bin

2014-01-01

The design and construction of shallow-buried tunnels in densely populated urban areas involve many challenges. The ground movements induced by tunneling effects pose potential risks to infrastructure such as surface buildings, pipelines, and roads. In this paper, a case study of the Zhongjie subway station located in Shenyang, China, is examined to investigate the key construction techniques and the influence of the Pile-Beam-Arch (PBA) excavation method on the surrounding environment. This case study discusses the primary risk factors affecting the environmental safety and summarizes the corresponding risk mitigation measures and key techniques for subway station construction using the PBA excavation method in a densely populated urban area.

Violence in Advertisements in New York City Subway Stations: A Pilot Study

Science.gov (United States)

Basch, Corey H.; Fullwood, M. D.; LeBlanc, Michael

2017-01-01

Violence has become a public health concern in the United States. Violent visually stimulating content encompasses various techniques such as fear, humor, shock, or violence, to stimulate a response or appeal toward awareness of human emotion. Exposing impressionable youth to violent advertisements can be particularly problematic. This is especially true in places like New York City where violent crime is a prevalent problem. With annual ridership reaching over 1.7 billion in 2014, the New York City subway system is abundant with advertisements. The purpose of this pilot study was to determine the frequency and type of violent advertising on the Lexington Avenue/East Side Line in New York City, running through the Bronx and Manhattan to represent the lower and higher median income earning boroughs. There were no statistically different findings in median household income at site of station by number of ads or source of violent. Destruction was the most common form of violence (n = 32, 42.7 %) followed by intent to strike (n = 18, 24 %), showing a weapon (n = 15, 20 %) and horror (n = 10, 13.3 %). Most ads (n = 46, 61.3 %) were found in stations heading uptown toward and through the Bronx, the borough where median household income is lowest, whereas 29 (38.7 %) were found in stations heading downtown. Future studies could focus on additional boroughs and subways lines, and could be collected at multiple points in time to determine of how prevalent violent advertising is throughout New York City and at different time frames. PMID:26518776

Violence in Advertisements in New York City Subway Stations: A Pilot Study.

Science.gov (United States)

Basch, Corey H; Fullwood, M D; LeBlanc, Michael

2016-04-01

Violence has become a public health concern in the United States. Violent visually stimulating content encompasses various techniques such as fear, humor, shock, or violence, to stimulate a response or appeal toward awareness of human emotion. Exposing impressionable youth to violent advertisements can be particularly problematic. This is especially true in places like New York City where violent crime is a prevalent problem. With annual ridership reaching over 1.7 billion in 2014, the New York City subway system is abundant with advertisements. The purpose of this pilot study was to determine the frequency and type of violent advertising on the Lexington Avenue/East Side Line in New York City, running through the Bronx and Manhattan to represent the lower and higher median income earning boroughs. There were no statistically different findings in median household income at site of station by number of ads or source of violent. Destruction was the most common form of violence (n = 32, 42.7 %) followed by intent to strike (n = 18, 24 %), showing a weapon (n = 15, 20 %) and horror (n = 10, 13.3 %). Most ads (n = 46, 61.3 %) were found in stations heading uptown toward and through the Bronx, the borough where median household income is lowest, whereas 29 (38.7 %) were found in stations heading downtown. Future studies could focus on additional boroughs and subways lines, and could be collected at multiple points in time to determine of how prevalent violent advertising is throughout New York City and at different time frames.

Effects of Experimentally Imposed Noise on Task Performance of Black Children Attending Day Care Centers Near Elevated Subway Trains.

Science.gov (United States)

Hambrick-Dixon, Priscilla Janet

1986-01-01

Investigates whether an experimentally imposed 80dB (A) noise affected psychomotor, serial memory words and pictures, incidental memory, visual recall, paired associates, perceptual learning, and coding performance of five-year-old Black children attending day care centers near and far from elevated subways. (HOD)

Analytical Study on Dynamic Response of Deep Foundation Pit Support Structure under the Action of Subway Train Vibration Load: A Case Study of Deep Foundation Pit of the New Museum Near Metro Line 2 in Chengdu, China

Directory of Open Access Journals (Sweden)

Zhu Dapeng

2015-01-01

Full Text Available Presently, foundation pit support structures are generally regarded as the temporary structures and the impact of vibration loads is often overlooked. As opposed to static and seismic loads, the vibration loads of subway trains are a type of cyclic load with a relatively long duration of action and a definite cycle; it is of great importance for the design of foundation pit support structures to correctly evaluate the impact of subway train vibrations on deep foundation pit and support works. In this paper, a dynamic three-dimensional numerical model is built that considers the vibration load of subway trains on the basis of the static numerical model for deep foundation pit support structures and simplified train loads to study the impact of train vibrations on deep foundation pit and permanent support structures. Studies have shown that the dynamic response of surface displacement mainly occurs in the early period of dynamic load, the vibration load of subway trains has little impact on ground subsidence, the support pile structure is in an elastic state during dynamic response under the action of subway train vibrations, and the action of train vibration loads is inimical to the safety of foundation pit support structures and should be closely studied.

Research on Matrix-type Packet Loss Compensation Scheme for Wireless Video Transmission on Subway

Directory of Open Access Journals (Sweden)

Fan Qing-Wu

2017-01-01

Full Text Available As the mainstream wireless LAN technology, Wi-Fi can achieve fast data transfer. With the subway moving in a high speed, video data transmission between the metro and the ground is achieved through Wi-Fi technology. This paper aims at solving the Caton problem caused by switching packet loss in the process of playing real-time video on the train terminal, and proposes matrix-type packet loss compensation scheme. Finally, the feasibility of the scheme is verified by experiments.

Key Techniques and Risk Management for the Application of the Pile-Beam-Arch (PBA Excavation Method: A Case Study of the Zhongjie Subway Station

Directory of Open Access Journals (Sweden)

Yong-ping Guan

2014-01-01

Full Text Available The design and construction of shallow-buried tunnels in densely populated urban areas involve many challenges. The ground movements induced by tunneling effects pose potential risks to infrastructure such as surface buildings, pipelines, and roads. In this paper, a case study of the Zhongjie subway station located in Shenyang, China, is examined to investigate the key construction techniques and the influence of the Pile-Beam-Arch (PBA excavation method on the surrounding environment. This case study discusses the primary risk factors affecting the environmental safety and summarizes the corresponding risk mitigation measures and key techniques for subway station construction using the PBA excavation method in a densely populated urban area.

Stray current monitoring at Nuremberg subway; Streustromueberwachung bei der U-Bahn Nuernberg

Energy Technology Data Exchange (ETDEWEB)

Altmann, M.; Halfmann, U.; Schneider, E. [Siemens AG, Erlangen (Germany). TS EL EN 2; Roesch, N. [VAG Verkehrs-AG Nuernberg, FA/SA - Starkstromanlagen, Nuernberg (Germany)

2004-05-01

Operating DC traction systems requires protective measures against the effects of stray currents. Damage by corrosion could occur both at railway and third party installations. The continuous effectiveness of protective measures needs to be monitored and recorded during revenue operation, and shall be capable to be demonstrated to supervising authorities. Measuring the rail-to-earth potential within the traction network under operational conditions, combined with centralized analysis, visualization, signaling and archiving is a straightforward and efficient method of stray current monitoring. For more than one year, the stray current monitoring system SITRAS SMS {sup registered} has been undergoing successful field application at the Nuremberg Subway. (orig.)

The Tokyo subway sarin attack-lessons learned

International Nuclear Information System (INIS)

Okumura, T.; Hisaoka, T.; Yamada, A.; Naito, T.; Isonuma, H.; Okumura, S.; Miura, K.; Sakurada, M.; Maekawa, H.; Ishimatsu, S.; Takasu, N.; Suzuki, K.

2005-01-01

The sarin gas attack in the Tokyo subway system is reviewed from a clinical toxicology perspective. Based on the lessons learned from this attack, the following areas should be addressed on a global scale. First, an adequate supply of protective equipment is required, including level B protective equipment with a pressure demand breathing apparatus. In addition, a system should be established that enables a possible cause to be determined based on symptoms, physical findings, general laboratory tests, and a simple qualitative analysis for poisonous substances. If an antidote is needed, the system should enable it to be administered to the victims as quickly as possible. Preparation for a large-scale chemical attack by terrorists requires the prior establishment of a detailed decontamination plan that utilizes not only mass decontamination facilities but also public facilities in the area. A system should be established for summarizing, evaluating, and disseminating information on poisonous substances. Finally, a large-scale scientific investigation of the Tokyo sarin attack should be conducted to examine its long-term and subclinical effects and the effects of exposure to asymptomatic low levels of sarin

Strength Analysis and Process Simulation of Subway Contact Rail Support Bracket of Composite Materials

Science.gov (United States)

Fedulov, Boris N.; Safonov, Alexander A.; Sergeichev, Ivan V.; Ushakov, Andrey E.; Klenin, Yuri G.; Makarenko, Irina V.

2016-10-01

An application of composites for construction of subway brackets is a very effective approach to extend their lifetime. However, this approach involves the necessity to prevent process-induced distortions of the bracket due to thermal deformation and chemical shrinkage. At present study, a process simulation has been carried out to support the design of the production tooling. The simulation was based on the application of viscoelastic model for the resin. Simulation results were verified by comparison with results of manufacturing experiments. To optimize the bracket structure the strength analysis was carried out as well.

[WORKING CONDITIONS AND STATE OF HEALTH OF TBILISI SUBWAY EMPLOYEES].

Science.gov (United States)

Khunashvili, N; Tsimakuridze, Mar; Bakradze, L; Khachapuridze, N; Tsimakuridze, Maya

2017-03-01

For the purpose of preventive events complex hygienic, clinical-functional, laboratory and biostatic researches are implemented on the basis of Tbilisi Subway. Conditions of work are characterized by complex of unfavorable factors of the working environment and the labor process. Working environment is characterized by combination of unfavorable state of physical factors and air pollution with dust and toxic substances. The levels of noise and vibration refer to the 3.4 class of harmfulness. The content of dust and toxic substances corresponds to 3.1-3.2 classes of working conditions harmfulness. In the indexes of health status, the leading diseases are pathology of cardiovascular, nervous and digestive systems. Cause-effect relationships between working conditions and individual health indicators have been already established, which served as the basis for the development of comprehensive preventive health measures.

Development of the safety control framework for shield tunneling in close proximity to the operational subway tunnels: case studies in mainland China.

Science.gov (United States)

Li, Xinggao; Yuan, Dajun

2016-01-01

China's largest cities like Beijing and Shanghai have seen a sharp increase in subway network development as a result of the rapid urbanization in the last decade. The cities are still expanding their subway networks now, and many shield tunnels are being or will be constructed in close proximity to the existing operational subway tunnels. The execution plans for the new nearby shield tunnel construction calls for the development of a safety control framework-a set of control standards and best practices to help organizations manage the risks involved. Typical case studies and relevant key technical parameters are presented with a view to presenting the resulting safety control framework. The framework, created through collaboration among the relevant parties, addresses and manages the risks in a systematic way based on actual conditions of each tunnel crossing construction. The framework consists of six parts: (1) inspecting the operational subway tunnels; (2) deciding allowed movements of the existing tunnels and tracks; (3) simulating effects of the shield tunneling on the existing tunnels; (4) doing preparation work; (5) monitoring design and information management; and (6) measures and activation mechanism of the countermeasures. The six components are explained and demonstrated in detail. In the end, discussions made involve construction and post-construction settlement of the operational tunnel, application of the remedial grouting to rectify excessive settlements of the operational tunnel, and use of the innovative tool of the optical fiber measurement for tunnel movement monitoring. It is concluded that the construction movement of the tunnel can be controlled within 15 mm when the shield machine is <7 m in excavation diameter. The post-construction settlement of the tunnel buried in the very soft ground is much greater than its construction settlement, and last several years until reaching a final stable state. Two cases are outlined to demonstrate the

Study on Vibration Reduction Method for a Subway Station in Soft Ground

Directory of Open Access Journals (Sweden)

Xian-Feng Ma

2017-01-01

Full Text Available With the rapid development of metro system in urban areas, vibration and its impact on adjacent structures caused by metro operation have drawn much attention of researches and worries relating to it have risen. This paper analyzed the vibration attenuation and the environment impact by a case study of a subway station in soft ground with adjacent laboratory building. A method of setting a compound separation barrier surrounding the station is checked and different materials used in the barrier have been tried and tested through numerical analysis. Key parameters of the material and the effects of vibration reduction are studied with the purpose that similar methodology and findings can be referenced in future practices.

A Case Study on Stratified Settlement and Rebound Characteristics due to Dewatering in Shanghai Subway Station

OpenAIRE

Wang, Jianxiu; Huang, Tianrong; Sui, Dongchang

2013-01-01

Based on the Yishan Metro Station Project of Shanghai Metro Line number 9, a centrifugal model test was conducted to investigate the behavior of stratified settlement and rebound (SSR) of Shanghai soft clay caused by dewatering in deep subway station pit. The soil model was composed of three layers, and the dewatering process was simulated by self-invention of decompressing devise. The results indicate that SSR occurs when the decompression was carried out, and only negative rebound was found...

GPR applied to mapping utilities along the route of the Line 4 (yellow) subway tunnel construction in São Paulo City, Brazil

Science.gov (United States)

Porsani, Jorge Luís; Ruy, Yang Boo; Ramos, Fernanda Pereira; Yamanouth, Gisele R. B.

2012-05-01

The rapid industrial development and disorganized population growth in huge cities bring about various urban problems due to intense use of physical space on and below the surface. Subsurface problems in metropolitan areas are caused by subway line construction, which often follows the routes of utility networks, such as electric and telephone cables, water and gas pipes, storm sewers, etc. Usually, the main problems are related to damage or destruction of preexisting utilities, often putting human lives at risk. With the purpose of minimizing risks, GPR-profiling with 200 MHz antennae was done at two sites, both located in downtown São Paulo, Brazil. The objectives of this work were to map utilities or existing infrastructure in the subsurface in order to orient the construction of the Line 4 (yellow) subway tunnel in São Paulo. GPR profiles can detect water pipes, utility networks in the subsurface, and concrete foundation columns or pilings in subsoil up to 2 m depth. In addition, the GPR profiles also provided details of the target shapes in the subsurface. GPR interpretations combined with lithological information from boreholes and trenches opened in the study areas were extremely important in mapping of the correct spatial distribution of buried utilities at these two sites in São Paulo. This information improves and updates maps of utility placement, serves as a basis for planning of the geotechnical excavation of the Line 4 (yellow) subway tunnel in São Paulo, helps minimize problems related to destruction of preexisting utilities in the subsoil, and avoids risk of dangerous accidents.

Large eddy simulation of cooling flows in underground subway station according to different PSD operating conditions

Energy Technology Data Exchange (ETDEWEB)

Jang, Yong Jun; Kim, Jin Ho; Park, Sung Huk; Koo, Dong Hoe [Korea Railroad Research Institute, Uiwang (Korea, Republic of)

2015-11-15

Large eddy simulation (LES) method is applied to systematically investigate the cooling fluid flow and the temperature distribution under the operating of air conditioning in the deeply underground subway station. The Shin-Gum-Ho subway station in Seoul which is the 8{sup th} floor and 43.6 m deep is selected for this analysis. The entire station is covered for simulation. The ventilation mode for air conditioning is kept as ordinary state. Different operating conditions for Platform screen door (PSD) are applied. First one is PSD is completely close and second one is PSD is regularly open and close which imitate the actual circumstances in the platform. The ventilation diffusers are modeled as 95 square shapes in the lobby and 222 squares in the platform. The temperature variations and flow behaviors are numerically simulated after operating of air conditioning for the whole station and the calculated results are compared with experimental data. LES method solves the momentum and thermal equations. Werner-Wengle wall law is applied to viscous sub layers for near wall resolution. The total grid numbers are 7.5 million and the whole domain is divided to 22 blocks. Multi blocks are computed in parallel using MPI. The results show the temperature difference in the platform between PSD-close and PSD-regularly open and close cases is 3-4 .deg. C.

Large eddy simulation of cooling flows in underground subway station according to different PSD operating conditions

International Nuclear Information System (INIS)

Jang, Yong Jun; Kim, Jin Ho; Park, Sung Huk; Koo, Dong Hoe

2015-01-01

Large eddy simulation (LES) method is applied to systematically investigate the cooling fluid flow and the temperature distribution under the operating of air conditioning in the deeply underground subway station. The Shin-Gum-Ho subway station in Seoul which is the 8"t"h floor and 43.6 m deep is selected for this analysis. The entire station is covered for simulation. The ventilation mode for air conditioning is kept as ordinary state. Different operating conditions for Platform screen door (PSD) are applied. First one is PSD is completely close and second one is PSD is regularly open and close which imitate the actual circumstances in the platform. The ventilation diffusers are modeled as 95 square shapes in the lobby and 222 squares in the platform. The temperature variations and flow behaviors are numerically simulated after operating of air conditioning for the whole station and the calculated results are compared with experimental data. LES method solves the momentum and thermal equations. Werner-Wengle wall law is applied to viscous sub layers for near wall resolution. The total grid numbers are 7.5 million and the whole domain is divided to 22 blocks. Multi blocks are computed in parallel using MPI. The results show the temperature difference in the platform between PSD-close and PSD-regularly open and close cases is 3-4 .deg. C

Personal exposure to particulate matter in commuters using different transport modes (bus, bicycle, car and subway) in an assigned route in downtown Santiago, Chile.

Science.gov (United States)

Suárez, Liliana; Mesías, Stephanie; Iglesias, Verónica; Silva, Claudio; Cáceres, Dante D; Ruiz-Rudolph, Pablo

2014-05-01

The objective of this study was to compare personal exposure to particulate matter (fine and ultrafine particles) in commuters using different transport modes (bicycle, bus, car and subway) in a busy, assigned route in downtown Santiago, Chile. Volunteers carrying personal samplers completed scheduled commutes during the morning rush hours, while central site measurements were conducted in parallel. A total of 137 valid commutes were assessed. The impact of central site, traffic and other variables was explored with regression models. PM2.5 personal concentrations were equal to or slightly above central site measurements, while UFP personal concentrations were above them. Regression models showed impacts of both background levels and traffic emissions on personal PM2.5 and UFP exposure. Traffic impacts varied with transport modes. Estimates of traffic impacts on personal PM2.5 exposure were 2.0, 13.0, 16.9 and 17.5 μg m(-3), for car, bicycle, subway and bus, respectively; while for UFP exposure were 8400, 16 200, 25 600 and 30 100 counts per cm(3), for subway, car, bicycle and bus, respectively. After controlling the central site and transport mode, higher temperatures increased PM2.5 exposure and decreased UFP ones, while the wind direction affected UFP personal exposure. In conclusion, we found significant impacts of both central site background measurements and traffic emissions on personal exposure of volunteer commuters in an assigned route in Santiago, with impacts varying with transport modes.

Continuous Extraction of Subway Tunnel Cross Sections Based on Terrestrial Point Clouds

Directory of Open Access Journals (Sweden)

Zhizhong Kang

2014-01-01

Full Text Available An efficient method for the continuous extraction of subway tunnel cross sections using terrestrial point clouds is proposed. First, the continuous central axis of the tunnel is extracted using a 2D projection of the point cloud and curve fitting using the RANSAC (RANdom SAmple Consensus algorithm, and the axis is optimized using a global extraction strategy based on segment-wise fitting. The cross-sectional planes, which are orthogonal to the central axis, are then determined for every interval. The cross-sectional points are extracted by intersecting straight lines that rotate orthogonally around the central axis within the cross-sectional plane with the tunnel point cloud. An interpolation algorithm based on quadric parametric surface fitting, using the BaySAC (Bayesian SAmpling Consensus algorithm, is proposed to compute the cross-sectional point when it cannot be acquired directly from the tunnel points along the extraction direction of interest. Because the standard shape of the tunnel cross section is a circle, circle fitting is implemented using RANSAC to reduce the noise. The proposed approach is tested on terrestrial point clouds that cover a 150-m-long segment of a Shanghai subway tunnel, which were acquired using a LMS VZ-400 laser scanner. The results indicate that the proposed quadric parametric surface fitting using the optimized BaySAC achieves a higher overall fitting accuracy (0.9 mm than the accuracy (1.6 mm obtained by the plain RANSAC. The results also show that the proposed cross section extraction algorithm can achieve high accuracy (millimeter level, which was assessed by comparing the fitted radii with the designed radius of the cross section and comparing corresponding chord lengths in different cross sections and high efficiency (less than 3 s/section on average.

Hyperloops, Nuclear Spacecraft, and the New York City Subway

Science.gov (United States)

Granade, Stephen

2014-03-01

Frustrated by the speed and high cost-per-mile of the California High-Speed Rail project linking Los Angeles with San Francisco, Elon Musk proposed the Hyperloop: a high-speed train running in a sealed, partially-evacuated tube. Musk released a white paper that described the technology and concluded that the Hyperloop could be built for less than a tenth of a cost of the California High-Speed Rail. Musk's white paper focused heavily on the scientific and technical questions that must be answered, but public transportation is a domain at the intersection of science and society. Public transportation infrastructure is shaped as much by the pressures of government and citizens as by the technology behind the transportation. Tube-based transport like the Hyperloop has been proposed before, but has never gone further than words on a page. Why? Historical examples like the development of the New York City subway and the proposed nuclear-powered Orion spacecraft shed light on the societal barriers that new transportation must overcome, and help illuminate why technology-based answers are not a full response to transportation questions.

Effect of Surface Blasting on Subway Tunnels- A Parametric Study

Directory of Open Access Journals (Sweden)

Hossein Entezari Zarch

2017-01-01

Full Text Available During wars and crises, the underground tunnels are used as a safe space. Therefore, the stability and safety of them under a blast is of particular importance. In this paper, the Finite Difference Method has been used to study the influence of the change in geotechnical parameters and depth on surface blasting on subway tunnels. Results showed that increasing the internal friction angle, modulus of elasticity and cohesion of the soil reduced the effects of blast loads on the vertical displacement and bending moment in the center of tunnel crown. Furthermore, the results showed that increasing the depth of the tunnel reduced the effects of blast loading. Comparing all parameters collectively showed that the increase in the modulus of elasticity of the soil and depth of the tunnel is the most effective in reducing the influence of the blast loads on the vertical displacement and bending moment of the tunnel crown, respectively.

Subway e skyway: infrastrutture sostenibili per la mobilità pedonale?

Directory of Open Access Journals (Sweden)

Enrica Papa

2008-12-01

Full Text Available L’articolo propone un approfondimento su una particolare tipologia di sistemi per la mobilità pedonale: le reti pedonali dedicate. Questa tipologia di infrastrutture per la mobilità pedonale è caratterizzata da assi pedonali sotterranei (subway e sopraelevati (skyway che si strutturano come complesse strutture percorribili solo a piedi. Gli esempi emblematici sono la più ampia rete pedonale sotterranea del mondo di Montreal, che raggiunge un estensione di 32km ed è conosciuta come la ville intérieure e la rete sopraelevata di Calgary, che supera i 16km di passaggi pedonali di collegamento tra diversi edifici commerciali e terziari. Partendo da un’analisi comparativa di casi di studio, l’articolo descrive gli elementi caratteristici delle reti pedonali “non convenzionali”, mettendo in evidenza i punti di forza e di debolezza di questi esempi in cui il flusso pedonale è totalmente separato dagli spazi dedicati al traffico veicolare.

Hydrogen sulfide adsorption on activated carbon fiber. Tests on Parisian subway; Elimination du sulfure d'hydrogene par adsorption sur tissu de charbon actif. Essais sur site RATP

Energy Technology Data Exchange (ETDEWEB)

Bouzaza, A.; Marsteau, St.; Laplanche, A. [Ecole Nationale Superieure de Chimie, Lab. Chimie des Nuissances et Genie de l' Environnement - CNGE, 35 - Rennes (France); Garrot, B. [RATP, Dept. Environnement et Securite-Domaines d' Expertises de l' Environnement-Entite Qualite de l' Air, 75 - Paris (France)

2003-06-01

Hydrogen sulfide has an unpleasant odor and may cause damage to the electrical materials of the Parisian subway. The activated carbon has some intrinsic catalytic activity, so the removal of hydrogen sulfide is due to an adsorption-oxidation process. In a laboratory scale, some kinetic parameters were acquired, which allowed us to build up two dynamic reactors. These continuous reactors, equipped with activated carbon fibers, were tested on the Madeleine station of the Parisian subway. The feasibility of the elimination of H{sub 2}S by continuous adsorption-oxidation was confirmed. The relative humidity of the gas phase was found to play an important role in the performance of the elimination. The durability of the pilot tested was compatible with an industrial exploitation of the process. (authors)

46 CFR 28.820 - Fire pumps, fire mains, fire hydrants, and fire hoses.

Science.gov (United States)

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Fire pumps, fire mains, fire hydrants, and fire hoses... REQUIREMENTS FOR COMMERCIAL FISHING INDUSTRY VESSELS Aleutian Trade Act Vessels § 28.820 Fire pumps, fire mains, fire hydrants, and fire hoses. (a) Each vessel must be equipped with a self-priming, power driven fire...

A comparative assessment of PM2.5 exposures in light-rail, subway, freeway, and surface street environments in Los Angeles and estimated lung cancer risk.

Science.gov (United States)

Kam, Winnie; Delfino, Ralph J; Schauer, James J; Sioutas, C

2013-01-01

According to the U.S. Census Bureau, 570000+ commuters in Los Angeles travel for over 60 minutes to work. Studies have shown that a substantial portion of particulate matter (PM) exposure can occur during this commute. This study represents the integration of the results from five commute environments in Los Angeles. Personal PM exposures are discussed for the: (1) METRO gold line, a ground-level light-rail route, (2) METRO red line, a subway line, (3) the 110, a high volume freeway with low heavy-duty vehicle (HDV) fraction, (4) the 710, a major corridor for HDVs from the Port of Los Angeles, and (5) Wilshire/Sunset Boulevards, major surface streets. Chemical analysis including total and water-soluble metals and trace elements, elemental and organic carbon (EC/OC), and polycyclic aromatic hydrocarbons (PAHs) was performed. The focus of this study is to compare the composition and estimated lung cancer risk of PM2.5 (dp subway), most likely from abrasion processes between the rail and brakes; elements associated with tire and brake wear and oil additives (Ca, Ti, Sn, Sb, and Pb) were elevated on roadways. Elemental concentrations on the gold line (light-rail) were the lowest. For water-solubility, metals observed on the red line (subway) were the least soluble. PAHs are primarily derived from vehicular emissions. Overall, the 710 exhibited high levels of PAHs (3.0 ng m−3), most likely due to its high volume of HDVs, while the red and gold lines exhibited low PAH concentrations (0.6 and 0.8 ng m−3 for red and gold lines, respectively). Lastly, lung cancer risk due to inhalation of PAHs was calculated based on a commuter lifetime (45 years for 2 hours per workday). Results showed that lung cancer risk for the 710 is 3.8 and 4.5 times higher than the light-rail (gold line) and subway (red line), respectively. With low levels of both metal and PAH pollutants, our results indicate that commuting on the light-rail (gold line) may have potential health benefits when

46 CFR 28.315 - Fire pumps, fire mains, fire hydrants, and fire hoses.

Science.gov (United States)

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Fire pumps, fire mains, fire hydrants, and fire hoses... After September 15, 1991, and That Operate With More Than 16 Individuals on Board § 28.315 Fire pumps, fire mains, fire hydrants, and fire hoses. (a) Each vessel 36 feet (11.8 meters) or more in length must...

Characteristics of PM10 and CO2 concentrations on 100 underground subway station platforms in 2014 and 2015

Science.gov (United States)

Hwang, Sung Ho; Park, Wha Me; Park, Jae Bum; Nam, Taegyun

2017-10-01

In this study, the concentrations of particulate matter 10 μm or less in diameter (PM10) and carbon dioxide (CO2) were measured in 100 underground subway stations, and the potential health risks of PM10, and environmental factors affecting these concentrations were analyzed. The concentrations were measured from May 2014 to September 2015 in stations along Seoul Metro lines 1-4. There were significantly different PM10 concentrations among the underground subway stations along lines 1, 2, 3, and 4. The PM10 concentrations were associated with the CO2 concentrations, construction years, station depths, and numbers of passengers. The underground PM10 concentrations were significantly higher than the outdoor PM10 concentrations. In addition, the PM10 concentrations were higher in the stations that were constructed in the 1970s than in those constructed after the 1970s. The PM10 and CO2 concentrations varied significantly, depending on the construction year and number of passengers. The hazard quotient is higher than the acceptable level of 1.0 μg kg-1 day for children, indicating that they are at risk of exposure to unsafe PM10 levels when travelling by the metro. Therefore, stricter management may be necessary for the stations constructed in the 1970s as well as those with higher numbers of passengers.

Radon and NO2 levels and related environmental factors in 100 underground subway platforms over two-year period.

Science.gov (United States)

Hwang, Sung Ho; Park, Jae Bum; Park, Wha Me

2018-01-01

In this study, the environmental factors that affect radon (Rn) and nitrogen dioxide (NO 2 ) levels in subway-station underground platforms are evaluated, and the outdoor NO 2 levels are compared with those obtained for the underground platforms. The Rn and NO 2 levels from May 2013 to September 2015 are determined for lines 1-4 of the Seoul Metro, via calculation of the arithmetic means of the Rn and NO 2 levels with their standard deviations (SDs). The underground Rn levels in 2013 are found to be significantly higher than those recorded in 2015 for the Seoul Metro. In addition, the Rn levels are related to the station depth and construction year. Further, the underground NO 2 levels are shown to be significantly higher than the outdoor levels for all four Seoul Metro subway lines. The Rn levels are also found to vary significantly between months, and are shown to increase gradually with depth from 8 to 20 m. The Rn levels are also higher for stations constructed in the 1980s. Therefore, stricter monitoring of Rn level may be required for stations constructed in the 1980s and/or having platform depths within the 8-20 m range. Island-type platform stations based on granite areas may also require careful attention. Copyright © 2017 Elsevier Ltd. All rights reserved.

Influence of slab length on dynamic characteristics of subway train-steel spring floating slab track-tunnel coupled system

Directory of Open Access Journals (Sweden)

Qing-yuan Xu

Full Text Available A subway train-steel spring floating slab track-tunnel coupling dynamic model, considering short and middle-long wavelength random track irregularities, and longitudinal connection between adjacent slabs of steel spring floating slab track, was developed. And the influence of slab length on dynamic characteristics of the system under different track conditions and train speeds are theoretically studied. The calculated results show: (1 In general, the acceleration of each component of the coupled system decreases with the increase of slab length under the perfectly smooth track condition; (2 Slab length has different influence laws on acceleration of each component of subway train-steel spring floating slab track-tunnel coupled system under random irregularity of track condition. The lower the dominant frequency distribution of vibration acceleration is, the higher influence slab length has; (3 With the increase of slab length, the force of rail, fastener and steel spring also decreases significantly, which helps to lengthen the service life of these components; (4 With the increase of slab length, the longitudinal bending moment of slab increases sharply at first, then it begins to drop slightly. When slab length exceeds the distance between two bogies of a vehicle, the longitudinal bending moment of slab changes little; (5 Slab length has significant influence on the dynamic force and displacement of the coupled system when train speed is higher.

An investigation of the PM2.5 and NO2 concentrations and their human health impacts in the metro subway system of Suzhou, China.

Science.gov (United States)

Cao, Shi-Jie; Kong, Xiang-Ri; Li, Linyan; Zhang, Weirong; Ye, Zi-Ping; Deng, Yelin

2017-05-24

This study measured the particle concentrations with an aerodynamic diameter smaller than 2.5 μm (PM 2.5 ), nitrogen dioxide (NO 2 ), and relative humidity (RH) at five metro subway stations in Suzhou's subway system (Lines 1 and 2). The real-time monitoring campaign was conducted from March 30 th to April 10 th and August 4 th to August 21 st , 2015. The monitoring practice was carried out during rush (7:00-9:00 AM and 17:00-19:00 PM) and regular hours (other times) at the ground and underground levels under different weather conditions with a purpose of obtaining representative data. The monitored results show that the concentrations of PM 2.5 in the train carriages were lower than the concentrations at the underground platforms during both spring and summer. The mean PM 2.5 concentrations at all the underground platforms in all the sub-stations monitored were significantly higher than those at the ground level. The human health impact was calculated to be 6300 annual DALYs (or 375 deaths) due to exposure to the subway system in Suzhou according to the UNEP-SETAC toxicity (USEtox) model. Linear regression models were applied to evaluate the relationships between the PM 2.5 , NO 2 concentrations, and RH. We found that a 10% increment in RH from the current average level of 50-60% can lead to a 9.8 μg m -3 concentration decrease in PM 2.5 . This further results in the total human health impact being reduced to 2451 DALYs (150-4753 DALYs), representing a 20% decrease (1.2-38%).

Investigation of air pollution of Shanghai subway stations in ventilation seasons in terms of PM2.5 and PM10.

Science.gov (United States)

Guo, Erbao; Shen, Henggen; He, Lei; Zhang, Jiawen

2017-07-01

In November 2015, the PM 2.5 and PM 10 particulate matter (PM) levels in platforms, station halls, and rail areas of the Shangcheng and Jiashan Road Station were monitored to investigate air pollution in the Shanghai subway system. The results revealed that in subway stations, PM 2.5 and PM 10 concentrations were significantly higher than those in outdoor environments. In addition, particle concentrations in the platforms exceeded maximum levels that domestic safety standards allowed. Particularly on clear days, PM 2.5 and PM 10 concentrations in platforms were significantly higher than maximum standards levels. Owing to the piston effect, consistent time-varying trends were exhibited by PM 2.5 concentrations in platforms, station halls, and rail areas. Platform particle concentrations were higher than the amount in station halls, and they were higher on clear days than on rainy days. The time-varying trends of PM 10 and PM 2.5 concentrations in platforms and station halls were similar to each other. Activities within the station led to most of the inhalable particles within the station area. The mass concentration ratios of PM 2.5 and PM 10 in platforms were within 0.65-0.93, and fine particles were the dominant components.

Análisis de la elección de la pierna de ataque predominante en la prueba de 400 m vallas de los XIII Campeonatos del Mundo de Atletismo Daegu 2011

Directory of Open Access Journals (Sweden)

José Luis López del Amo

2012-12-01

Full Text Available Objetivos: Analizar la utilización de una u otra pierna como pierna de ataque predominante en atletas de 400 m vallas de alto nivel. Método: El estudio es descriptivo de corte transversal. Se estudiaron todas las carreras de 400 m vallas de los 72 participantes (34 hombres y 38 mujeres en los XIII Campeonatos del Mundo de Atletismo Daegu 2011, mediante la grabación en video desde la tribuna principal del Daegu Stadium de las 18 carreras de 400 m vallas disputadas, y el posterior análisis mediante la aplicación informática Kinovea 0.8.4. Resultados: Por atletas, en el total de las carreras masculinas, la pierna de ataque predominante fue la izquierda con un 63,6 % (42 atletas y con la pierna derecha hubo un 34,8 % (23 atletas. Solo en un caso había un equilibrio entre izquierda y derecha. En la final hubo un 75 % (6 atletas cuya pierna predominante de ataque fue la izquierda. En cuanto a las mujeres, la pierna de ataque predominante fue la izquierda con un 48,6 % seguida de la pierna derecha con un 41,4 % y para el 10 % había un equilibrio de las dos. En la final, en cambio, la pierna predominante de ataque fue la derecha con un 87,5 % (7 atletas por un 12,5 % de la izquierda (1 sola atleta. Se encontraron diferencias significativas (p = 0,018 en la media de tiempo final de los atletas masculinos según cual fuera su pierna de ataque. Conclusiones: La mayoría de los atletas atacan las vallas con derecha e izquierda en algún momento de la carrera, lo que obliga al dominio técnico bilateral. La pierna de ataque más utilizada es la izquierda, aunque en menor medida en el caso de las mujeres. Por primera vez en una gran competición, 7 de las 8 finalistas tienen la pierna derecha como pierna predominante.

TERT-CLPTM1 locus polymorphism (rs401681) is associated with the prognosis of hepatocellular carcinoma

OpenAIRE

Lee, Hye Won; Park, Won-Jin; Heo, Yu-Ran; Park, Tae In; Park, Soo Young; Lee, Jae-Ho

2017-01-01

Hye Won Lee,1,* Won-Jin Park,2,* Yu-Ran Heo,2 Tae In Park,3 Soo Young Park,4 Jae-Ho Lee2,* 1Department of Pathology, Keimyung University School of Medicine, Daegu, Republic of Korea; 2Department of Anatomy, Keimyung University School of Medicine, Daegu, Republic of Korea; 3Department of Pathology, Kyungpook National University School of Medicine, Daegu, Republic of Korea; 4Department of Internal Medicine, Kyungpook National University School of Medicine, Daegu, Republic of Korea *T...

An understanding of human dynamics in urban subway traffic from the Maximum Entropy Principle

Science.gov (United States)

Yong, Nuo; Ni, Shunjiang; Shen, Shifei; Ji, Xuewei

2016-08-01

We studied the distribution of entry time interval in Beijing subway traffic by analyzing the smart card transaction data, and then deduced the probability distribution function of entry time interval based on the Maximum Entropy Principle. Both theoretical derivation and data statistics indicated that the entry time interval obeys power-law distribution with an exponential cutoff. In addition, we pointed out the constraint conditions for the distribution form and discussed how the constraints affect the distribution function. It is speculated that for bursts and heavy tails in human dynamics, when the fitted power exponent is less than 1.0, it cannot be a pure power-law distribution, but with an exponential cutoff, which may be ignored in the previous studies.

[MICROCLIMATE CONDITION IN SUBWAY CARS IN THE SUMMER PERIOD OF THE YEAR].

Science.gov (United States)

Leksin, A G; Evlampieva, M N; Timoshenkova, E V; Morgunov, A V; Kaptsov, V A

2015-01-01

There are presented the results of the work, which aims to identify the relationship between the temperature of air in the salons of subway cars from the heat output of passengers in different people occupancy of cars during "peak hours", and to determine the efficacy offorced air handling regular ventilation or air conditioning system to remove the elevated heat load on passengers. In the work there was used the method of calculating the amount of heat output of 215 passengers (nominal fullness of the chamber) and the simulation method of heat and moisture output of the same number of passengers. The operating system of ventilation has been shown to fail to decline the average temperature of the air in the passenger compartment to the optimum values and most efficient approach for the reducing the heat load on the passengers is the use of air conditioning systems.

Removal of particulate matter emitted from a subway tunnel using magnetic filters.

Science.gov (United States)

Son, Youn-Suk; Dinh, Trieu-Vuong; Chung, Sang-Gwi; Lee, Jai-Hyo; Kim, Jo-Chun

2014-01-01

We removed particulate matter (PM) emitted from a subway tunnel using magnetic filters. A magnetic filter system was installed on the top of a ventilation opening. Magnetic field density was increased by increasing the number of permanent magnet layers to determine PM removal characteristics. Moreover, the fan's frequency was adjusted from 30 to 60 Hz to investigate the effect of wind velocity on PM removal efficiency. As a result, PM removal efficiency increased as the number of magnetic filters or fan frequency increased. We obtained maximum removal efficiency of PM10 (52%), PM2.5 (46%), and PM1 (38%) at a 60 Hz fan frequency using double magnetic filters. We also found that the stability of the PM removal efficiency by the double filter (RSD, 3.2-5.8%) was higher than that by a single filter (10.9-24.5%) at all fan operating conditions.

Subway. Logistické řešení pro střední a východní Evropu

OpenAIRE

Benschová, Šárka

2008-01-01

Subway is the leading fast food franchise chain having over 29.700 branches in 87 countries and differentiating itself among other fast foods by serving healthy food. The chain's focus for further development is concentrated on the countries in Central Europe (Czech Republic, Poland, Hungary and Croatia) and its 47 branches. However, the concept of supply chain in this region is disunited and leads to unfair high costs and high requirements from the branch management. Therefore there is an ur...

Urinary 8-hydroxy-deoxyguanosine as a biomarker of oxidative DNA damage in employees of subway system.

Science.gov (United States)

Mehrdad, Ramin; Aghdaei, Sara; Pouryaghoub, Gholamreza

2015-01-01

Exposure to air pollutants, steel dust or other occupational and environmental hazards as oxidative stress have adverse effects on subway workers' health. Oxidative stress generates an excessive amount of reactive oxygen species (ROS) and Oxygen Free Radicals during their work time in the tunnels. Once DNA is repaired, Urinary 8-hydroxy-deoxyguanosine (8-OHdG) is excreted in the urine. Therefore, urinary level of 8-OHdG can reflect the extent of oxidative DNA damage. The aim of this study was to document the oxidative stress caused by exposure to these hazards by measuring 8-OHdG in workers urine. We collected urine samples of 81 male subway workers after their working shift. The concentration of urinary 8-OHdG was measured by ELISA method. We used linear regression analysis to compare the level of urinary 8-OHdG as a biomarker of oxidative stress between workers in tunnels and other staff. The mean concentration of urinary 8-OHdG for workers in the tunnel was 58.05 (SD=28.83) ng/mg creatinine and for another staff was 54.16 (SD =26.98) ng/mg creatinine.  After adjustment for age, smoking, driving and a second job in a linear regression model, the concentration of 8-OHdG for the exposed group was significantly higher than unexposed group (P=0.038). These findings confirm that the concentration of urinary 8-OHdG for workers who work in tunnels was significantly higher than the other staff. Additional investigations should be performed to understand that which ones of occupational exposures are more important to cause oxidative stress.

Hamburg subway vehicles with new control and traction systems; Hamburger U-Bahn-Fahrzeuge mit neuer Leit- und Antriebstechnik

Energy Technology Data Exchange (ETDEWEB)

Polster, H.J.; Lehr, G.; Werner-Wieland, P. [Bombardier Transportation, LRV, Mannheim (Germany)

2007-07-01

With a view to testing new technologies for future vehicle series for the Hamburg subway network, the last 17 DT4 cars to be delivered under a current contract were equipped with the latest generation of control and traction systems. A MITRAC control system was installed instead of the MICAS-S type used in the DT4 vehicles delivered before. The GTO converters were replaced by IGBT elements. The concept is designed to allow for the change-over of DT4 vehicles of previous series to the new system. (orig.)

NeuroLines: A Subway Map Metaphor for Visualizing Nanoscale Neuronal Connectivity.

Science.gov (United States)

Al-Awami, Ali K; Beyer, Johanna; Strobelt, Hendrik; Kasthuri, Narayanan; Lichtman, Jeff W; Pfister, Hanspeter; Hadwiger, Markus

2014-12-01

We present NeuroLines, a novel visualization technique designed for scalable detailed analysis of neuronal connectivity at the nanoscale level. The topology of 3D brain tissue data is abstracted into a multi-scale, relative distance-preserving subway map visualization that allows domain scientists to conduct an interactive analysis of neurons and their connectivity. Nanoscale connectomics aims at reverse-engineering the wiring of the brain. Reconstructing and analyzing the detailed connectivity of neurons and neurites (axons, dendrites) will be crucial for understanding the brain and its development and diseases. However, the enormous scale and complexity of nanoscale neuronal connectivity pose big challenges to existing visualization techniques in terms of scalability. NeuroLines offers a scalable visualization framework that can interactively render thousands of neurites, and that supports the detailed analysis of neuronal structures and their connectivity. We describe and analyze the design of NeuroLines based on two real-world use-cases of our collaborators in developmental neuroscience, and investigate its scalability to large-scale neuronal connectivity data.

NeuroLines: A Subway Map Metaphor for Visualizing Nanoscale Neuronal Connectivity

KAUST Repository

Al-Awami, Ali K.; Beyer, Johanna; Strobelt, Hendrik; Kasthuri, Narayanan; Lichtman, Jeff W.; Pfister, Hanspeter; Hadwiger, Markus

2014-01-01

We present NeuroLines, a novel visualization technique designed for scalable detailed analysis of neuronal connectivity at the nanoscale level. The topology of 3D brain tissue data is abstracted into a multi-scale, relative distance-preserving subway map visualization that allows domain scientists to conduct an interactive analysis of neurons and their connectivity. Nanoscale connectomics aims at reverse-engineering the wiring of the brain. Reconstructing and analyzing the detailed connectivity of neurons and neurites (axons, dendrites) will be crucial for understanding the brain and its development and diseases. However, the enormous scale and complexity of nanoscale neuronal connectivity pose big challenges to existing visualization techniques in terms of scalability. NeuroLines offers a scalable visualization framework that can interactively render thousands of neurites, and that supports the detailed analysis of neuronal structures and their connectivity. We describe and analyze the design of NeuroLines based on two real-world use-cases of our collaborators in developmental neuroscience, and investigate its scalability to large-scale neuronal connectivity data.

NeuroLines: A Subway Map Metaphor for Visualizing Nanoscale Neuronal Connectivity

KAUST Repository

Al-Awami, Ali K.

2014-12-31

We present NeuroLines, a novel visualization technique designed for scalable detailed analysis of neuronal connectivity at the nanoscale level. The topology of 3D brain tissue data is abstracted into a multi-scale, relative distance-preserving subway map visualization that allows domain scientists to conduct an interactive analysis of neurons and their connectivity. Nanoscale connectomics aims at reverse-engineering the wiring of the brain. Reconstructing and analyzing the detailed connectivity of neurons and neurites (axons, dendrites) will be crucial for understanding the brain and its development and diseases. However, the enormous scale and complexity of nanoscale neuronal connectivity pose big challenges to existing visualization techniques in terms of scalability. NeuroLines offers a scalable visualization framework that can interactively render thousands of neurites, and that supports the detailed analysis of neuronal structures and their connectivity. We describe and analyze the design of NeuroLines based on two real-world use-cases of our collaborators in developmental neuroscience, and investigate its scalability to large-scale neuronal connectivity data.

Respiratory effects of particulate matter air pollution: studies on diesel exhaust, road tunnel, subway and wood smoke exposure in human subjects

Energy Technology Data Exchange (ETDEWEB)

Sehlstedt, Maria

2011-07-01

Background: Ambient air pollution is associated with adverse health effects, but the sources and components, which cause these effects is still incompletely understood. The aim of this thesis was to investigate the pulmonary effects of a variety of common air pollutants, including diesel exhaust, biomass smoke, and road tunnel and subway station environments. Healthy non-smoking volunteers were exposed in random order to the specific air pollutants and air/control, during intermittent exercise, followed by bronchoscopy. Methods and results: In study I, exposures were performed with diesel exhaust (DE) generated at transient engine load and air for 1 hour with bronchoscopy at 6 hours post-exposure. Immunohistochemical analyses of bronchial mucosal biopsies showed that DE exposure significantly increased the endothelial adhesion molecule expression of p-selectin and VCAM-1, together with increased bronchoalveolar lavage (BAL) eosinophils. In study II, the subjects were exposed for 1 hour to DE generated during idling with bronchoscopy at 6 hours. The bronchial mucosal biopsies showed significant increases in neutrophils, mast cells and lymphocytes together with bronchial wash neutrophils. Additionally, DE exposure significantly increased the nuclear translocation of the aryl hydrocarbon receptor (AhR) and phosphorylated c-jun in the bronchial epithelium. In contrast, the phase II enzyme NAD(P)H-quinone oxidoreductase 1 (NQO1) decreased after DE. In study III, the 2-hour exposures took place in a road tunnel with bronchoscopy 14 hours later. The road tunnel exposure significantly increased the total numbers of lymphocytes and alveolar macrophages in BAL, whereas NK cell and CD56+/T cell numbers significantly decreased. Additionally, the nuclear expression of phosphorylated c-jun in the bronchial epithelium was significantly increased after road tunnel exposure. In study IV, the subjects were exposed to metal-rich particulate aerosol for 2 hours at a subway station

A long-time limit for world subway networks.

Science.gov (United States)

Roth, Camille; Kang, Soong Moon; Batty, Michael; Barthelemy, Marc

2012-10-07

We study the temporal evolution of the structure of the world's largest subway networks in an exploratory manner. We show that, remarkably, all these networks converge to a shape that shares similar generic features despite their geographical and economic differences. This limiting shape is made of a core with branches radiating from it. For most of these networks, the average degree of a node (station) within the core has a value of order 2.5 and the proportion of k = 2 nodes in the core is larger than 60 per cent. The number of branches scales roughly as the square root of the number of stations, the current proportion of branches represents about half of the total number of stations, and the average diameter of branches is about twice the average radial extension of the core. Spatial measures such as the number of stations at a given distance to the barycentre display a first regime which grows as r(2) followed by another regime with different exponents, and eventually saturates. These results--difficult to interpret in the framework of fractal geometry--confirm and yield a natural explanation in the geometric picture of this core and their branches: the first regime corresponds to a uniform core, while the second regime is controlled by the interstation spacing on branches. The apparent convergence towards a unique network shape in the temporal limit suggests the existence of dominant, universal mechanisms governing the evolution of these structures.

Wildland fire limits subsequent fire occurrence

Science.gov (United States)

Sean A. Parks; Carol Miller; Lisa M. Holsinger; Scott Baggett; Benjamin J. Bird

2016-01-01

Several aspects of wildland fire are moderated by site- and landscape-level vegetation changes caused by previous fire, thereby creating a dynamic where one fire exerts a regulatory control on subsequent fire. For example, wildland fire has been shown to regulate the size and severity of subsequent fire. However, wildland fire has the potential to influence...

Chemical Characterization of Outdoor and Subway Fine (PM2.5-1.0) and Coarse (PM10-2.5) Particulate Matter in Seoul (Korea) Computer-Controlled Scanning Electron Microscopy (CCSEM)

Science.gov (United States)

Outdoor and indoor (subway) samples were collected by passive sampling in urban Seoul and analyzed with computer-controlled scanning electron microscopy coupled with energy dispersive x-ray spectroscopy (CCSEM-EDX). Soil/road dust particles accounted for 42-60% (by weight) of fin...

Conflicts of Interest and Change in Original Intent: A Case Study of Vacant and Abandoned Homes Repurposed as Community Gardens in a Shrinking City, Daegu, South Korea

Directory of Open Access Journals (Sweden)

Jin-Wook Lee

2017-11-01

Full Text Available As part of an urban policy designed to revive South Korea’s shrinking cities, vacant residential structures are being demolished and the resulting empty plots transformed into public spaces. This study discursively examines this process, its stakeholders, and the sources of conflict among them in the neighborhood of Daebong 2 in Daegu, South Korea. Additionally, solutions for maintaining public interest are explored. Employees and members of relevant municipal authorities and non-profit organizations (NPOs, as well as town residents, were selected through purposive sampling for interviews. The data were then analyzed via open coding. The results reveal conflict between users and non-users in terms of the possession of public goods, as well as conflict between project executives in the creation process. We also found that spatial and policy characteristics are a particular source of conflict in dense, historic residential areas. To overcome problems caused by rivalry and discord, the following actions are required: a change in perspective among policy practitioners; a governance structure that consists of a public/private/community partnership; consensus among community members, and; equitable welfare through programs based on inclusivity and public interest.

Determination of future prevention strategies in elite track and field: analysis of Daegu 2011 IAAF Championships injuries and illnesses surveillance

Science.gov (United States)

Alonso, Juan-Manuel; Edouard, Pascal; Fischetto, Giuseppe; Adams, Bob; Depiesse, Frédéric; Mountjoy, Margo

2012-01-01

Objective To determine the incidence and characteristics of newly incurred injuries and illnesses during international Athletics Championships, by improving the medical surveillance coverage, in order to determine future prevention strategies. Design Prospective recording of newly occurred injuries and illnesses. Setting 13th International Association of Athletics Federations World Championships in Athletics 2011 in Daegu, Korea. Participants National team and Local Organising Committee physicians; and 1851 registered athletes. Main outcome measures Incidence and characteristics of newly incurred injuries and illnesses. Results 82% of athletes were covered by medical teams participating with a response rate of 94%. A total of 249 injuries were reported, representing an incidence of 134.5 injuries per 1000 registered athletes, and 119 (48%) resulted in time loss from sport. A total of 185 injuries affected the lower limb (74%). Hamstring strain was the main diagnosis and 67% resulted in absence from sport. Overuse (n=148; 59%) was the predominant cause. A total of 126 illnesses were reported, signifying an incidence of 68.1 per 1000 registered athletes. Upper respiratory tract infection was the most common reported diagnosis (18%), followed by exercise-induced dehydration (12%), and gastroenteritis/diarrhoea (10%). The highest incidences of injuries were found in combined events and middle and long-distance events, and of illness in race walking events. Conclusion During elite Athletics World Championships, 135 injuries, 60 time-loss injuries and 68 illnesses per 1000 registered athletes were reported. Higher risks of injuries were found in combined events and long-distance runs. Preventive interventions should focus on overuse injuries and hamstring strains, decreasing the risk of transmission of infectious diseases, appropriate event scheduling and heat acclimatisation. PMID:22522588

Health risk assessment of volatile organic compounds exposure near Daegu dyeing industrial complex in South Korea.

Science.gov (United States)

Shuai, Jianfei; Kim, Sunshin; Ryu, Hyeonsu; Park, Jinhyeon; Lee, Chae Kwan; Kim, Geun-Bae; Ultra, Venecio U; Yang, Wonho

2018-04-20

Studying human health in areas with industrial contamination is a serious and complex issue. In recent years, attention has increasingly focused on the health implications of large industrial complexes. A variety of potential toxic chemicals have been produced during manufacturing processes and activities in industrial complexes in South Korea. A large number of dyeing industries gathered together in Daegu dyeing industrial complex. The residents near the industrial complex could be often exposed to volatile organic compounds. This study aimed to evaluate VOCs levels in the ambient air of DDIC, to assess the impact on human health risks, and to find more convincing evidences to prove these VOCs emitted from DDIC. According to deterministic risk assessment, inhalation was the most important route. Residential indoor, outdoor and personal exposure air VOCs were measured by passive samplers in exposed area and controlled area in different seasons. Satisfaction with ambient environments and self-reported diseases were also obtained by questionnaire survey. The VOCs concentrations in exposed area and controlled area was compared by t-test. The relationships among every VOC were tested by correlation. The values of hazard quotient (HQ) and life cancer risk were estimated. The concentrations of measured VOCs were presented, moreover, the variety of concentrations according the distances from the residential settings to the industrial complex site in exposed area. The residential indoor, outdoor, and personal exposure concentrations of toluene, DMF and chloroform in exposed area were significantly higher than the corresponding concentrations in controlled area both in summer and autumn. Toluene, DMF, chloroform and MEK had significantly positive correlations with each other in indoor and outdoor, and even in personal exposure. The HQ for DMF exceeded 1, and the life cancer risk of chloroform was greater than 10 - 4 in exposed area. The prevalence of respiratory diseases

Indoor radon distribution of subway stations in a Korean major city

International Nuclear Information System (INIS)

Yoon, Seokwon; Chang, Byung-Uck; Kim, Yongjae; Byun, Jong-In; Yun, Ju-Yong

2010-01-01

The overall survey on indoor radon concentration was conducted at all subway stations in a major city, Daejeon in the central part of Korea. It was quarterly performed from September 2007 to August 2008. The annual arithmetic mean of indoor radon concentration of all the stations was 34.1 ± 14.7 Bq m -3 , and the range of values was from 9.4 to 98.2 Bq m -3 . The radon concentrations in groundwater (average 31.0 ± 0.8 Bq m -3 ) were not significantly high in most stations, but the concentration (177.9 ± 2.3 Bq L -1 ) of one station was over the level of 148 Bq L -1 in drinking water proposed by U.S. EPA. Based on indoor survey results, the approximate average of the annual effective dose by radon inhalation to the employees and passengers were 0.24 mSv y -1 , and 0.02 mSv y -1 , respectively. Although the effective dose based on the UNSCEAR report was potentially estimated, for more accurate assessment, the additional survey on the influence by indoor radon will be necessary.

Indoor radon distribution of subway stations in a Korean major city

Energy Technology Data Exchange (ETDEWEB)

Yoon, Seokwon [Korea Institute of Nuclear Safety, Gwahak-ro 34, Yuseong-gu, 305-338 Daejeon (Korea, Republic of); Chang, Byung-Uck, E-mail: hafadai@kins.re.k [Korea Institute of Nuclear Safety, Gwahak-ro 34, Yuseong-gu, 305-338 Daejeon (Korea, Republic of); University of Science and Technology, Gwahak-ro 113, Yuseong-gu, 305-333 Daejeon (Korea, Republic of); Kim, Yongjae [Korea Institute of Nuclear Safety, Gwahak-ro 34, Yuseong-gu, 305-338 Daejeon (Korea, Republic of); Byun, Jong-In [University of Science and Technology, Gwahak-ro 113, Yuseong-gu, 305-333 Daejeon (Korea, Republic of); Yun, Ju-Yong [Korea Institute of Nuclear Safety, Gwahak-ro 34, Yuseong-gu, 305-338 Daejeon (Korea, Republic of); University of Science and Technology, Gwahak-ro 113, Yuseong-gu, 305-333 Daejeon (Korea, Republic of)

2010-04-15

The overall survey on indoor radon concentration was conducted at all subway stations in a major city, Daejeon in the central part of Korea. It was quarterly performed from September 2007 to August 2008. The annual arithmetic mean of indoor radon concentration of all the stations was 34.1 +- 14.7 Bq m{sup -3}, and the range of values was from 9.4 to 98.2 Bq m{sup -3}. The radon concentrations in groundwater (average 31.0 +- 0.8 Bq m{sup -3}) were not significantly high in most stations, but the concentration (177.9 +- 2.3 Bq L{sup -1}) of one station was over the level of 148 Bq L{sup -1} in drinking water proposed by U.S. EPA. Based on indoor survey results, the approximate average of the annual effective dose by radon inhalation to the employees and passengers were 0.24 mSv y{sup -1}, and 0.02 mSv y{sup -1}, respectively. Although the effective dose based on the UNSCEAR report was potentially estimated, for more accurate assessment, the additional survey on the influence by indoor radon will be necessary.

Automatic and efficient methods applied to the binarization of a subway map

Science.gov (United States)

Durand, Philippe; Ghorbanzadeh, Dariush; Jaupi, Luan

2015-12-01

The purpose of this paper is the study of efficient methods for image binarization. The objective of the work is the metro maps binarization. the goal is to binarize, avoiding noise to disturb the reading of subway stations. Different methods have been tested. By this way, a method given by Otsu gives particularly interesting results. The difficulty of the binarization is the choice of this threshold in order to reconstruct. Image sticky as possible to reality. Vectorization is a step subsequent to that of the binarization. It is to retrieve the coordinates points containing information and to store them in the two matrices X and Y. Subsequently, these matrices can be exported to a file format 'CSV' (Comma Separated Value) enabling us to deal with them in a variety of software including Excel. The algorithm uses quite a time calculation in Matlab because it is composed of two "for" loops nested. But the "for" loops are poorly supported by Matlab, especially in each other. This therefore penalizes the computation time, but seems the only method to do this.

FIRE

International Nuclear Information System (INIS)

Brtis, J.S.; Hausheer, T.G.

1990-01-01

FIRE, a microcomputer based program to assist engineers in reviewing and documenting the fire protection impact of design changes has been developed. Acting as an electronic consultant, FIRE is designed to work with an experienced nuclear system engineer, who may not have any detailed fire protection expertise. FIRE helps the engineer to decide if a modification might adversely affect the fire protection design of the station. Since its first development, FIRE has been customized to reflect the fire protection philosophy of the Commonwealth Edison Company. That program is in early production use. This paper discusses the FIRE program in light of its being a useful application of expert system technologies in the power industry

A Review of Fire Interactions and Mass Fires

Directory of Open Access Journals (Sweden)

Mark A. Finney

2011-01-01

Full Text Available The character of a wildland fire can change dramatically in the presence of another nearby fire. Understanding and predicting the changes in behavior due to fire-fire interactions cannot only be life-saving to those on the ground, but also be used to better control a prescribed fire to meet objectives. In discontinuous fuel types, such interactions may elicit fire spread where none otherwise existed. Fire-fire interactions occur naturally when spot fires start ahead of the main fire and when separate fire events converge in one location. Interactions can be created intentionally during prescribed fires by using spatial ignition patterns. Mass fires are among the most extreme examples of interactive behavior. This paper presents a review of the detailed effects of fire-fire interaction in terms of merging or coalescence criteria, burning rates, flame dimensions, flame temperature, indraft velocity, pulsation, and convection column dynamics. Though relevant in many situations, these changes in fire behavior have yet to be included in any operational-fire models or decision support systems.

FIRES: Fire Information Retrieval and Evaluation System - A program for fire danger rating analysis

Science.gov (United States)

Patricia L. Andrews; Larry S. Bradshaw

1997-01-01

A computer program, FIRES: Fire Information Retrieval and Evaluation System, provides methods for evaluating the performance of fire danger rating indexes. The relationship between fire danger indexes and historical fire occurrence and size is examined through logistic regression and percentiles. Historical seasonal trends of fire danger and fire occurrence can be...

Fire propagation equation for the explicit identification of fire scenarios in a fire PSA

International Nuclear Information System (INIS)

Lim, Ho Gon; Han, Sang Hoon; Moon, Joo Hyun

2011-01-01

When performing fire PSA in a nuclear power plant, an event mapping method, using an internal event PSA model, is widely used to reduce the resources used by fire PSA model development. Feasible initiating events and component failure events due to fire are identified to transform the fault tree (FT) for an internal event PSA into one for a fire PSA using the event mapping method. A surrogate event or damage term method is used to condition the FT of the internal PSA. The surrogate event or the damage term plays the role of flagging whether the system/component in a fire compartment is damaged or not, depending on the fire being initiated from a specified compartment. These methods usually require explicit states of all compartments to be modeled in a fire area. Fire event scenarios, when using explicit identification, such as surrogate or damage terms, have two problems: there is no consideration of multiple fire propagation beyond a single propagation to an adjacent compartment, and there is no consideration of simultaneous fire propagations in which an initiating fire event is propagated to multiple paths simultaneously. The present paper suggests a fire propagation equation to identify all possible fire event scenarios for an explicitly treated fire event scenario in the fire PSA. Also, a method for separating fire events was developed to make all fire events a set of mutually exclusive events, which can facilitate arithmetic summation in fire risk quantification. A simple example is given to confirm the applicability of the present method for a 2x3 rectangular fire area. Also, a feasible asymptotic approach is discussed to reduce the computational burden for fire risk quantification

Radon in the Underground Workplaces; Assessment of the Annual Effective Dose due to Inhaled Radon for the Seoul Subway Station Staffs

Energy Technology Data Exchange (ETDEWEB)

Song, Myeong Han; Chang, Byung Uck; Kim, Yong Jae [University of Science and Technology, Daejeon (Korea, Republic of); Lee, Hwa Yong [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of); Heo, Dong Hey [Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of)

2010-12-15

The effective dose of the Seoul subway staffs due to inhaled radon ({sup 222}Rn) in their workplace was investigated depended on radon concentration exposed at each workplace, and working hours and working types of the staffs. Annual average radon concentrations ranged from 16.5 to 93.0 Bq·m{sup -3}. The staffs commonly spend 2,304 hours in the underground spaces a year. With the radon concentrations and the working hours of the staffs, estimated annual effective doses ranged from 0.23 to 0.73 mSv·y{sup -1}.

Radon in the Underground Workplaces; Assessment of the Annual Effective Dose due to Inhaled Radon for the Seoul Subway Station Staffs

International Nuclear Information System (INIS)

Song, Myeong Han; Chang, Byung Uck; Kim, Yong Jae; Lee, Hwa Yong; Heo, Dong Hey

2010-01-01

The effective dose of the Seoul subway staffs due to inhaled radon ( 222 Rn) in their workplace was investigated depended on radon concentration exposed at each workplace, and working hours and working types of the staffs. Annual average radon concentrations ranged from 16.5 to 93.0 Bq·m -3 . The staffs commonly spend 2,304 hours in the underground spaces a year. With the radon concentrations and the working hours of the staffs, estimated annual effective doses ranged from 0.23 to 0.73 mSv·y -1

Temporal variability of the bioaerosol background at a subway station: concentration level, size distribution, and diversity of airborne bacteria.

Science.gov (United States)

Dybwad, Marius; Skogan, Gunnar; Blatny, Janet Martha

2014-01-01

Naturally occurring bioaerosol environments may present a challenge to biological detection-identification-monitoring (BIODIM) systems aiming at rapid and reliable warning of bioterrorism incidents. One way to improve the operational performance of BIODIM systems is to increase our understanding of relevant bioaerosol backgrounds. Subway stations are enclosed public environments which may be regarded as potential bioterrorism targets. This study provides novel information concerning the temporal variability of the concentration level, size distribution, and diversity of airborne bacteria in a Norwegian subway station. Three different air samplers were used during a 72-h sampling campaign in February 2011. The results suggested that the airborne bacterial environment was stable between days and seasons, while the intraday variability was found to be substantial, although often following a consistent diurnal pattern. The bacterial levels ranged from not detected to 10(3) CFU m(-3) and generally showed increased levels during the daytime compared to the nighttime levels, as well as during rush hours compared to non-rush hours. The airborne bacterial levels showed rapid temporal variation (up to 270-fold) on some occasions, both consistent and inconsistent with the diurnal profile. Airborne bacterium-containing particles were distributed between different sizes for particles of >1.1 μm, although ∼50% were between 1.1 and 3.3 μm. Anthropogenic activities (mainly passengers) were demonstrated as major sources of airborne bacteria and predominantly contributed 1.1- to 3.3-μm bacterium-containing particles. Our findings contribute to the development of realistic testing and evaluation schemes for BIODIM equipment by providing information that may be used to simulate operational bioaerosol backgrounds during controlled aerosol chamber-based challenge tests with biological threat agents.

Temporal Variability of the Bioaerosol Background at a Subway Station: Concentration Level, Size Distribution, and Diversity of Airborne Bacteria

Science.gov (United States)

Dybwad, Marius; Skogan, Gunnar

2014-01-01

Naturally occurring bioaerosol environments may present a challenge to biological detection-identification-monitoring (BIODIM) systems aiming at rapid and reliable warning of bioterrorism incidents. One way to improve the operational performance of BIODIM systems is to increase our understanding of relevant bioaerosol backgrounds. Subway stations are enclosed public environments which may be regarded as potential bioterrorism targets. This study provides novel information concerning the temporal variability of the concentration level, size distribution, and diversity of airborne bacteria in a Norwegian subway station. Three different air samplers were used during a 72-h sampling campaign in February 2011. The results suggested that the airborne bacterial environment was stable between days and seasons, while the intraday variability was found to be substantial, although often following a consistent diurnal pattern. The bacterial levels ranged from not detected to 103 CFU m−3 and generally showed increased levels during the daytime compared to the nighttime levels, as well as during rush hours compared to non-rush hours. The airborne bacterial levels showed rapid temporal variation (up to 270-fold) on some occasions, both consistent and inconsistent with the diurnal profile. Airborne bacterium-containing particles were distributed between different sizes for particles of >1.1 μm, although ∼50% were between 1.1 and 3.3 μm. Anthropogenic activities (mainly passengers) were demonstrated as major sources of airborne bacteria and predominantly contributed 1.1- to 3.3-μm bacterium-containing particles. Our findings contribute to the development of realistic testing and evaluation schemes for BIODIM equipment by providing information that may be used to simulate operational bioaerosol backgrounds during controlled aerosol chamber-based challenge tests with biological threat agents. PMID:24162566

Comparison of the characteristics of fire and non-fire households in the 2004-2005 survey of fire department-attended and unattended fires.

Science.gov (United States)

Greene, Michael A

2012-06-01

Comparison of characteristics of fire with non-fire households to determine factors differentially associated with fire households (fire risk factors). National household telephone survey in 2004-2005 by the US Consumer Product Safety Commission with 916 fire households and a comparison sample of 2161 non-fire households. There were an estimated 7.4 million fires (96.6% not reported to fire departments) with 130,000 injuries. Bivariate analysis and multivariate logistic regression analyses to assess differences in household characteristics. Significant factors associated with fire households were renting vs. owning (OR 1.988 pfire households with non-cooking fires (OR 1.383 p=0.0011). Single family houses were associated with non-fire households in the bivariate analysis but not in the multivariate analyses. Renting, household members under 18 years old and smokers are risk factors for unattended fires, similar to the literature for fatal and injury fires. Differences included household members over 65 years old (associated with non-fire households), college/postgraduate education (associated with fire households) and lack of significance of income. Preventing cooking fires (64% of survey incidents), smoking prevention efforts and fire prevention education for families with young children have the potential for reducing unattended fires and injuries.

Calculation of Fire Severity Factors and Fire Non-Suppression Probabilities For A DOE Facility Fire PRA

International Nuclear Information System (INIS)

Elicson, Tom; Harwood, Bentley; Lucek, Heather; Bouchard, Jim

2011-01-01

Over a 12 month period, a fire PRA was developed for a DOE facility using the NUREG/CR-6850 EPRI/NRC fire PRA methodology. The fire PRA modeling included calculation of fire severity factors (SFs) and fire non-suppression probabilities (PNS) for each safe shutdown (SSD) component considered in the fire PRA model. The SFs were developed by performing detailed fire modeling through a combination of CFAST fire zone model calculations and Latin Hypercube Sampling (LHS). Component damage times and automatic fire suppression system actuation times calculated in the CFAST LHS analyses were then input to a time-dependent model of fire non-suppression probability. The fire non-suppression probability model is based on the modeling approach outlined in NUREG/CR-6850 and is supplemented with plant specific data. This paper presents the methodology used in the DOE facility fire PRA for modeling fire-induced SSD component failures and includes discussions of modeling techniques for: Development of time-dependent fire heat release rate profiles (required as input to CFAST), Calculation of fire severity factors based on CFAST detailed fire modeling, and Calculation of fire non-suppression probabilities.

A review of fire interactions and mass fires

Science.gov (United States)

Mark A. Finney; Sara S. McAllister

2011-01-01

The character of a wildland fire can change dramatically in the presence of another nearby fire. Understanding and predicting the changes in behavior due to fire-fire interactions cannot only be life-saving to those on the ground, but also be used to better control a prescribed fire to meet objectives. In discontinuous fuel types, such interactions may elicit fire...

Fire characteristics charts for fire behavior and U.S. fire danger rating

Science.gov (United States)

Faith Ann Heinsch; Pat Andrews

2010-01-01

The fire characteristics chart is a graphical method of presenting U.S. National Fire Danger Rating indices or primary surface or crown fire behavior characteristics. A desktop computer application has been developed to produce fire characteristics charts in a format suitable for inclusion in reports and presentations. Many options include change of scales, colors,...

Fire protection and fire fighting in nuclear installations

International Nuclear Information System (INIS)

1989-01-01

Fires are a threat to all technical installations. While fire protection has long been a well established conventional discipline, its application to nuclear facilities requires special considerations. Nevertheless, for a long time fire engineering has been somewhat neglected in the design and operation of nuclear installations. In the nuclear industry, the Browns Ferry fire in 1975 brought about an essential change in the attention paid to fire problems. Designers and plant operators, as well as insurance companies and regulators, increased their efforts to develop concepts and methods for reducing fire risks, not only to protect the capital investment in nuclear plants but also to consider the potential secondary effects which could lead to nuclear accidents. Although the number of fires in nuclear installations is still relatively large, their overall importance to the safety of nuclear power plants was not considered to be very high. Only more recently have probabilistic analyses changed this picture. The results may well have to be taken into account more carefully. Various aspects of fire fighting and fire protection were discussed during the Symposium, the first of its kind to be organized by the IAEA. It was convened in co-operation with several organizations working in the nuclear or fire protection fields. The intention was to gather experts from nuclear engineering areas and the conventional fire protection field at one meeting with a view to enhancing the exchange of information and experience and to presenting current knowledge on the various disciplines involved. The presentations at the meeting were subdivided into eight sessions: standards and licensing (6 papers); national fire safety practices (7 papers); fire safety by design (11 papers); fire fighting (2 papers); computer fire modeling (7 papers); fire safety in fuel center facilities (7 papers); fire testing of materials (3 papers); fire risk assessment (5 papers). A separate abstract was

Resolving vorticity-driven lateral fire spread using the WRF-Fire coupled atmosphere–fire numerical model

OpenAIRE

Simpson, C. C.; Sharples, J. J.; Evans, J. P.

2014-01-01

Fire channelling is a form of dynamic fire behaviour, during which a wildland fire spreads rapidly across a steep lee-facing slope in a direction transverse to the background winds, and is often accompanied by a downwind extension of the active flaming region and extreme pyro-convection. Recent work using the WRF-Fire coupled atmosphere-fire model has demonstrated that fire channelling can be characterised as vorticity-driven lateral fire spread (VDLS). In t...

Sensitivity Analysis on Fire Modeling of Main Control Board Fire Using Fire Dynamics Simulator

International Nuclear Information System (INIS)

Kang, Dae Il; Lim, Ho Gon

2015-01-01

In this study, sensitivity analyses for an MCB fire were performed to identify the effects on the MCR forced abandonment time according to the changes of height and number for fire initiation places. Hanul Unit 3 NPP was selected as a reference plant for this study. In this study, sensitivity analyses for an MCB fire were performed to identify the effects on the MCR forced abandonment time according to the changes of height and number of fire initiation places. A main control board (MCB) fire can cause a forced main control room (MCR) abandonment of the operators as well as the function failures or spurious operations of the control and instrumentation-related components. If the MCR cannot be habitable, a safe shutdown from outside the MCR can be achieved and maintained at an alternate shutdown panel independent from the MCR. When the fire modeling for an electrical cabinet such as an MCB was performed, its many input parameters can affect the fire simulation results. This study results showed that the decrease in the height of fire ignition place and the use of single fire ignition place in fire modeling for the propagating fire shortened MCR abandonment time

Sensitivity Analysis on Fire Modeling of Main Control Board Fire Using Fire Dynamics Simulator

Energy Technology Data Exchange (ETDEWEB)

Kang, Dae Il; Lim, Ho Gon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2015-10-15

In this study, sensitivity analyses for an MCB fire were performed to identify the effects on the MCR forced abandonment time according to the changes of height and number for fire initiation places. Hanul Unit 3 NPP was selected as a reference plant for this study. In this study, sensitivity analyses for an MCB fire were performed to identify the effects on the MCR forced abandonment time according to the changes of height and number of fire initiation places. A main control board (MCB) fire can cause a forced main control room (MCR) abandonment of the operators as well as the function failures or spurious operations of the control and instrumentation-related components. If the MCR cannot be habitable, a safe shutdown from outside the MCR can be achieved and maintained at an alternate shutdown panel independent from the MCR. When the fire modeling for an electrical cabinet such as an MCB was performed, its many input parameters can affect the fire simulation results. This study results showed that the decrease in the height of fire ignition place and the use of single fire ignition place in fire modeling for the propagating fire shortened MCR abandonment time.

A case study on stratified settlement and rebound characteristics due to dewatering in Shanghai subway station.

Science.gov (United States)

Wang, Jianxiu; Huang, Tianrong; Sui, Dongchang

2013-01-01

Based on the Yishan Metro Station Project of Shanghai Metro Line number 9, a centrifugal model test was conducted to investigate the behavior of stratified settlement and rebound (SSR) of Shanghai soft clay caused by dewatering in deep subway station pit. The soil model was composed of three layers, and the dewatering process was simulated by self-invention of decompressing devise. The results indicate that SSR occurs when the decompression was carried out, and only negative rebound was found in sandy clay, but both positive and negative rebound occurred in the silty clay, and the absolute value of rebound in sandy clay was larger than in silty clay, and the mechanism of SSR was discussed with mechanical sandwich model, and it was found that the load and cohesive force of different soils was the main source of different responses when decompressed.

와인바 이용객의 만족도가 재방문 의사결정에 미치는 영향에 관한 연구

African Journals Online (AJOL)

AgroSan

2016-11-02

Nov 2, 2016 ... 4Department of Hotel, Restaurant, Culinary Arts, Wine and Coffee, Daegu Health College, Daegu 41422, Korea. ..... Influence of fermentation on the nutritional value of two varieties of ... In. Nutritional Value of Cereal Products,.

Fire protection

International Nuclear Information System (INIS)

Janetzky, E.

1980-01-01

Safety and fire prevention measurements have to be treated like the activities developing, planning, construction and erection. Therefore it is necessary that these measurements have to be integrated into the activities mentioned above at an early stage in order to guarantee their effectiveness. With regard to fire accidents the statistics of the insurance companies concerned show that the damage caused increased in the last years mainly due to high concentration of material. Organization of fire prevention and fire fighting, reasons of fire break out, characteristics and behaviour of fire, smoke and fire detection, smoke and heat venting, fire extinguishers (portable and stationary), construction material in presence of fire, respiratory protection etc. will be discussed. (orig./RW)

Evidence of fuels management and fire weather influencing fire severity in an extreme fire event.

Science.gov (United States)

Lydersen, Jamie M; Collins, Brandon M; Brooks, Matthew L; Matchett, John R; Shive, Kristen L; Povak, Nicholas A; Kane, Van R; Smith, Douglas F

2017-10-01

Following changes in vegetation structure and pattern, along with a changing climate, large wildfire incidence has increased in forests throughout the western United States. Given this increase, there is great interest in whether fuels treatments and previous wildfire can alter fire severity patterns in large wildfires. We assessed the relative influence of previous fuels treatments (including wildfire), fire weather, vegetation, and water balance on fire-severity in the Rim Fire of 2013. We did this at three different spatial scales to investigate whether the influences on fire severity changed across scales. Both fuels treatments and previous low to moderate-severity wildfire reduced the prevalence of high-severity fire. In general, areas without recent fuels treatments and areas that previously burned at high severity tended to have a greater proportion of high-severity fire in the Rim Fire. Areas treated with prescribed fire, especially when combined with thinning, had the lowest proportions of high severity. The proportion of the landscape burned at high severity was most strongly influenced by fire weather and proportional area previously treated for fuels or burned by low to moderate severity wildfire. The proportion treated needed to effectively reduce the amount of high severity fire varied by spatial scale of analysis, with smaller spatial scales requiring a greater proportion treated to see an effect on fire severity. When moderate and high-severity fire encountered a previously treated area, fire severity was significantly reduced in the treated area relative to the adjacent untreated area. Our results show that fuels treatments and low to moderate-severity wildfire can reduce fire severity in a subsequent wildfire, even when burning under fire growth conditions. These results serve as further evidence that both fuels treatments and lower severity wildfire can increase forest resilience. © 2017 by the Ecological Society of America.

Laboratory fire behavior measurements of chaparral crown fire

Science.gov (United States)

C. Sanpakit; S. Omodan; D. Weise; M Princevac

2015-01-01

In 2013, there was an estimated 9,900 wildland fires that claimed more than 577,000 acres of land. That same year, about 542 prescribed fires were used to treat 48,554 acres by several agencies in California. Being able to understand fires using laboratory models can better prepare individuals to combat or use fires. Our research focused on chaparral crown fires....

Wildland fire in ecosystems: effects of fire on flora

Science.gov (United States)

James K. Brown; Jane Kapler Smith

2000-01-01

VOLUME 2: This state-of-knowledge review about the effects of fire on flora and fuels can assist land managers with ecosystem and fire management planning and in their efforts to inform others about the ecological role of fire. Chapter topics include fire regime classification, autecological effects of fire, fire regime characteristics and postfire plant community...

The importance of fire simulation in fire prediction

Directory of Open Access Journals (Sweden)

Jevtić Radoje B.

2014-01-01

Full Text Available The appearance of fire in objects with lot of humans inside represents very possible real situation that could be very danger and could cause destructive consequences on human lives and material properties. Very important influence in fire prediction, fire protection, human and material properties safety could be a fire simulation in object. This simulation could give many useful information of possible fire propagation; possible and existed evacuation routes; possible and exited placing of fire, smoke, temperature conditions in object and many other information of crucial importance for human lives and material properties, such as the best places for sensors position, optimal number of sensors, projection of possible evacuation routes etc. There are many different programs for fire simulation. This paper presents complete fire simulation in Electrotechnical school Nikola Tesla in Niš in FDS.

Modelling the impact of causal and non-causal factors on disruption duration for Toronto's subway system: An exploratory investigation using hazard modelling.

Science.gov (United States)

Louie, Jacob; Shalaby, Amer; Habib, Khandker Nurul

2017-01-01

Most investigations of incident-related delay duration in the transportation context are restricted to highway traffic, with little attention given to delays due to transit service disruptions. Studies of transit-based delay duration are also considerably less comprehensive than their highway counterparts with respect to examining the effects of non-causal variables on the delay duration. However, delays due to incidents in public transit service can have serious consequences on the overall urban transportation system due to the pivotal and vital role of public transit. The ability to predict the durations of various types of transit system incidents is indispensable for better management and mitigation of service disruptions. This paper presents a detailed investigation on incident delay durations in Toronto's subway system over the year 2013, focusing on the effects of the incidents' location and time, the train-type involved, and the non-adherence to proper recovery procedures. Accelerated Failure Time (AFT) hazard models are estimated to investigate the relationship between these factors and the resulting delay duration. The empirical investigation reveals that incident types that impact both safety and operations simultaneously generally have longer expected delays than incident types that impact either safety or operations alone. Incidents at interchange stations are cleared faster than incidents at non-interchange stations. Incidents during peak periods have nearly the same delay durations as off-peak incidents. The estimated models are believed to be useful tools in predicting the relative magnitude of incident delay duration for better management of subway operations. Copyright © 2016 Elsevier Ltd. All rights reserved.

Adsorber fires

International Nuclear Information System (INIS)

Holmes, W.

1987-01-01

The following conclusions are offered with respect to activated charcoal filter systems in nuclear power plants: (1) The use of activated charcoal in nuclear facilities presents a potential for deep-seated fires. (2) The defense-in-depth approach to nuclear fire safety requires that if an ignition should occur, fires must be detected quickly and subsequently suppressed. (3) Deep-seated fires in charcoal beds are difficult to extinguish. (4) Automatic water sprays can be used to extinguish fires rapidly and reliably when properly introduced into the burning medium. The second part of the conclusions offered are more like challenges: (1) The problem associated with inadvertent actuations of fire protection systems is not a major one, and it can be reduced further by proper design review, installation, testing, and maintenance. Eliminating automatic fire extinguishing systems for the protection of charcoal adsorbers is not justified. (2) Removal of automatic fire protection systems due to fear of inadvertent fire protection system operation is a case of treating the effect rather than the cause. On the other hand, properly maintaining automatic fire protection systems will preserve the risk of fire loss at acceptable levels while at the same time reducing the risk of damage presented by inadvertent operation of fire protection systems

A Case Study on Stratified Settlement and Rebound Characteristics due to Dewatering in Shanghai Subway Station

Directory of Open Access Journals (Sweden)

Jianxiu Wang

2013-01-01

Full Text Available Based on the Yishan Metro Station Project of Shanghai Metro Line number 9, a centrifugal model test was conducted to investigate the behavior of stratified settlement and rebound (SSR of Shanghai soft clay caused by dewatering in deep subway station pit. The soil model was composed of three layers, and the dewatering process was simulated by self-invention of decompressing devise. The results indicate that SSR occurs when the decompression was carried out, and only negative rebound was found in sandy clay, but both positive and negative rebound occurred in the silty clay, and the absolute value of rebound in sandy clay was larger than in silty clay, and the mechanism of SSR was discussed with mechanical sandwich model, and it was found that the load and cohesive force of different soils was the main source of different responses when decompressed.

Uncovering stable and occasional human mobility patterns: A case study of the Beijing subway

Science.gov (United States)

Yong, Nuo; Ni, Shunjiang; Shen, Shifei; Chen, Peng; Ji, Xuewei

2018-02-01

There have generally been two kinds of approaches to the empirical study of human mobility. At the group level, some valuable information might be submerged in statistical noise, while due to the diversity of individual purpose and preference, there is still no general statistical regularity of human mobility at the individual level. In this paper, we considered group-level human mobility as the combination of several basic patterns and analyzed the collective mobility by category. Utilizing matrix factorization and correlation analysis, we extracted some of the stable/occasional components from the collective human mobility in the Beijing subway and found that the departure and arrival mobility patterns have different characteristics, both in time and space, under various conditions. We classified individual records into different patterns and analyzed the most likely trip distance by category. The proposed method can decompose stable/occasional mobility patterns from the collective mobility and identify passengers belonging to different patterns, helping us to better understand the origin of different mobility patterns and provide guidance for emergency management of large crowds.

Persuasion to use personal protective equipment in constructing subway stations: application of social marketing.

Science.gov (United States)

Shamsi, Mahmoud; Pariani, Abbas; Shams, Mohsen; Soleymani-nejad, Marzieh

2016-04-01

To study the effects of an intervention based on social marketing to persuade workers to use personal protective equipment (PPE) in constructing subway stations in Isfahan, Iran. This was a quasi-experimental study. Two stations were selected as intervention and control groups. Intervention was designed based on results of a formative research. A free package containing a safety helmet with a tailored message affixed to it, mask and gloves and an educational pamphlet was delivered to the intervention group. After 6 weeks, behaviours in the intervention and control stations were measured using an observational checklist. After the intervention, the percentage of workers who used PPE at the intervention station increased significantly. OR for helmet and mask usage was 7.009 and 2.235, respectively, in the intervention group. Social marketing can be used to persuade workers to use PPE in the workplace. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Risk assessment of main control board fire using fire dynamics simulator

Energy Technology Data Exchange (ETDEWEB)

Kang, Dae Il, E-mail: dikang@kaeri.re.kr [KAERI, 1045 Daedeokdaero, Yuseong-Gu, Daejeon 305-353 (Korea, Republic of); Kim, Kilyoo; Jang, Seung-Cheol [KAERI, 1045 Daedeokdaero, Yuseong-Gu, Daejeon 305-353 (Korea, Republic of); Yoo, Seong Yeon [Chungnam National University, 79, Daehagro, Yuseong-Gu, Daejeon (Korea, Republic of)

2015-08-15

Highlights: • A decision tree for evaluating the risk of a main control board (MCB) fire was proposed to systematically determine the MCB fire scenarios. • Fire simulations using fire dynamics simulator (FDS) were performed to estimate the time to MCR abandonment. • Non-propagating and propagating fire scenarios were considered for fire simulations. • The current study indicates that the quantification of the MCB fire risk should address the propagating fire and non-propagating fire scenarios if the MCB has no internal barriers between the panels. - Abstract: This paper presents the process and results of a risk assessment for a main control board (MCB) fire using fire dynamics simulator (FDS). A decision tree for evaluating the risk of a MCB fire was proposed to systematically determine the MCB fire scenarios, and fire simulations using FDS were performed to estimate the time to MCR abandonment. As a reference NPP for this study, Hanul unit 3 in Korea was selected and its core damage frequency (CDF) owing to the MCB fire was quantified. Two types of fire scenarios were considered for fire simulations: non-propagating fire scenarios occurring within a single MCB panel and propagating fire scenarios spreading from one control panel to the adjacent panels. Further, the fire scenarios were classified into fires with and without a heating, ventilation, and air conditioning system (HVACS). The fire simulation results showed that the major factor causing the MCR evacuation was the optical density irrelevant to the availability of the HVACS. The risk assessment results showed that the abandonment fire scenario risk was less than the non-abandonment fire scenario risk and the propagating fire scenario risk was greater than the non-propagating fire scenario risk.

Risk assessment of main control board fire using fire dynamics simulator

International Nuclear Information System (INIS)

Kang, Dae Il; Kim, Kilyoo; Jang, Seung-Cheol; Yoo, Seong Yeon

2015-01-01

Highlights: • A decision tree for evaluating the risk of a main control board (MCB) fire was proposed to systematically determine the MCB fire scenarios. • Fire simulations using fire dynamics simulator (FDS) were performed to estimate the time to MCR abandonment. • Non-propagating and propagating fire scenarios were considered for fire simulations. • The current study indicates that the quantification of the MCB fire risk should address the propagating fire and non-propagating fire scenarios if the MCB has no internal barriers between the panels. - Abstract: This paper presents the process and results of a risk assessment for a main control board (MCB) fire using fire dynamics simulator (FDS). A decision tree for evaluating the risk of a MCB fire was proposed to systematically determine the MCB fire scenarios, and fire simulations using FDS were performed to estimate the time to MCR abandonment. As a reference NPP for this study, Hanul unit 3 in Korea was selected and its core damage frequency (CDF) owing to the MCB fire was quantified. Two types of fire scenarios were considered for fire simulations: non-propagating fire scenarios occurring within a single MCB panel and propagating fire scenarios spreading from one control panel to the adjacent panels. Further, the fire scenarios were classified into fires with and without a heating, ventilation, and air conditioning system (HVACS). The fire simulation results showed that the major factor causing the MCR evacuation was the optical density irrelevant to the availability of the HVACS. The risk assessment results showed that the abandonment fire scenario risk was less than the non-abandonment fire scenario risk and the propagating fire scenario risk was greater than the non-propagating fire scenario risk

Fire-Walking

Science.gov (United States)

Willey, David

2010-01-01

This article gives a brief history of fire-walking and then deals with the physics behind fire-walking. The author has performed approximately 50 fire-walks, took the data for the world's hottest fire-walk and was, at one time, a world record holder for the longest fire-walk (www.dwilley.com/HDATLTW/Record_Making_Firewalks.html). He currently…

Forest-fire models

Science.gov (United States)

Haiganoush Preisler; Alan Ager

2013-01-01

For applied mathematicians forest fire models refer mainly to a non-linear dynamic system often used to simulate spread of fire. For forest managers forest fire models may pertain to any of the three phases of fire management: prefire planning (fire risk models), fire suppression (fire behavior models), and postfire evaluation (fire effects and economic models). In...

Fire Perimeters

Data.gov (United States)

California Natural Resource Agency — The Fire Perimeters data consists of CDF fires 300 acres and greater in size and USFS fires 10 acres and greater throughout California from 1950 to 2003. Some fires...

Fire History

Data.gov (United States)

California Natural Resource Agency — The Fire Perimeters data consists of CDF fires 300 acres and greater in size and USFS fires 10 acres and greater throughout California from 1950 to 2002. Some fires...

Electronic firing systems and methods for firing a device

Science.gov (United States)

Frickey, Steven J [Boise, ID; Svoboda, John M [Idaho Falls, ID

2012-04-24

An electronic firing system comprising a control system, a charging system, an electrical energy storage device, a shock tube firing circuit, a shock tube connector, a blasting cap firing circuit, and a blasting cap connector. The control system controls the charging system, which charges the electrical energy storage device. The control system also controls the shock tube firing circuit and the blasting cap firing circuit. When desired, the control system signals the shock tube firing circuit or blasting cap firing circuit to electrically connect the electrical energy storage device to the shock tube connector or the blasting cap connector respectively.

Fire weather conditions and fire-atmosphere interactions observed during low-intensity prescribed fires - RxCADRE 2012

Science.gov (United States)

Craig B. Clements; Neil P. Lareau; Daisuke Seto; Jonathan Contezac; Braniff Davis; Casey Teske; Thomas J. Zajkowski; Andrew T. Hudak; Benjamin C. Bright; Matthew B. Dickinson; Bret W. Butler; Daniel Jimenez; J. Kevin. Hiers

2016-01-01

The role of fire-atmosphere coupling on fire behaviour is not well established, and to date few field observations have been made to investigate the interactions between fire spread and fire-induced winds. Therefore, comprehensive field observations are needed to better understand micrometeorological aspects of fire spread. To address this need, meteorological...

Community participation in fire management planning: The Trinity county fire safe council's fire plan

Science.gov (United States)

Yvonne Everett

2008-01-01

In 1999, Trinity County CA, initiated a participatory fire management planning effort. Since that time, the Trinity County Fire Safe Council has completed critical portions of a fire safe plan and has begun to implement projects defined in the plan. Completion of a GIS based, landscape scale fuels reduction element in the plan defined by volunteer fire fighters, agency...

Managing wildland fires: integrating weather models into fire projections

Science.gov (United States)

Anne M. Rosenthal; Francis Fujioka

2004-01-01

Flames from the Old Fire sweep through lands north of San Bernardino during late fall of 2003. Like many Southern California fires, the Old Fire consumed susceptible forests at the urban-wildland interface and spread to nearby city neighborhoods. By incorporating weather models into fire perimeter projections, scientist Francis Fujioka is improving fire modeling as a...

Enhancing adaptive capacity for restoring fire-dependent ecosystems: the Fire Learning Network's Prescribed Fire Training Exchanges

Directory of Open Access Journals (Sweden)

Andrew G. Spencer

2015-09-01

Full Text Available Prescribed fire is a critical tool for promoting restoration and increasing resilience in fire-adapted ecosystems, but there are barriers to its use, including a shortage of personnel with adequate ecological knowledge and operational expertise to implement prescribed fire across multijurisdictional landscapes. In the United States, recognized needs for both professional development and increased use of fire are not being met, often because of institutional limitations. The Fire Learning Network has been characterized as a multiscalar, collaborative network that works to enhance the adaptive capacity of fire management institutions, and this network developed the Prescribed Fire Training Exchanges (TREXs to address persistent challenges in increasing the capacity for prescribed fire implementation. Our research was designed to investigate where fire professionals face professional barriers, how the TREX addresses these, and in what ways the TREX may be contributing to the adaptive capacity of fire management institutions. We evaluated the training model using surveys, interviews, focus groups, and participant observation. We found that, although the training events cannot overcome all institutional barriers, they incorporate the key components of professional development in fire; foster collaboration, learning, and network building; and provide flexible opportunities with an emphasis on local context to train a variety of professionals with disparate needs. The strategy also offers an avenue for overcoming barriers faced by contingent and nonfederal fire professionals in attaining training and operational experience, thereby increasing the variety of actors and resources involved in fire management. Although it is an incremental step, the TREX is contributing to the adaptive capacity of institutions in social-ecological systems in which fire is a critical ecological process.

US Fire Administration Fire Statistics

Data.gov (United States)

Department of Homeland Security — The U.S. Fire Administration collects data from a variety of sources to provide information and analyses on the status and scope of the fire problem in the United...

Experimental study of fire barriers preventing vertical fire spread in ETISs

Directory of Open Access Journals (Sweden)

Xin Huang

2013-11-01

Full Text Available In recent years, the external thermal insulation system (ETIS has been applied increasingly in a large amount of buildings for energy conservation purpose. However, the increase use of combustible insulation materials in the ETIS has raised serious fire safety problems. Fires involving this type of ETIS have caused severe damage and loss. In order to improve its fire safety, fire barriers were suggested to be installed. This paper introduces fire experiments that have been done to study the effects of fire barriers on preventing vertical fire spread along the ETIS. The experiments were performed according to BS 8414-1:2002 “Fire performance of external cladding systems – Part 1: Test method for non-loadbearing external cladding systems applied to the face of the building”. The test facility consists of a 9 m high wall. The fire sources were wood cribs with a fire size of 3 ± 0.5 MW. The insulation materials were expanded polystyrene foam (EPS. The fire barrier was a horizontal strip of rockwool with a width of 300 mm. Thermocouples were used to measure temperatures outside and inside the ETIS. A series of experiments with different fire scenarios were done: no fire barrier, two fire barriers and three fire barriers at different heights. Test results were compared. The results show that the ETIS using EPS without fire barriers almost burned out, while the ETIS with fire barriers performed well in preventing fire spread. The temperatures above the fire barrier were much lower than those below the fire barrier, and most of the insulation materials above the top fire barrier stayed in place.

Research of Emergency Smoke Exhausting in Running Subway Train%运行地铁列车应急排烟模式的研究

Institute of Scientific and Technical Information of China (English)

詹文元

2012-01-01

Taking head circumference of infants as the higher limit, numerical models of subway train getting fire in tunnel were established based on gas dynamics and combustion theory with the software FLUENT. Smoking-exhausting required time and pressure inside and outside of the train with different speed and opening door scheme was simulated, which showed that the smoke inside the railway carriage could be rapidly exhausted when the door opening degree was 0.07 m and the speed was 30 km/h. Experiment result in the Window of the world and the chiwan 2 Line of Shenzhen metro was consistent with numerical approach, which indicated numerical analysis for emergency smoke-exhausting mode was reliable with high accuracy.%通过初生婴儿的头围确定车门开度的上限值,利用气体动力学与燃烧学理论建立了地铁列车在隧道发生火灾时的数值分析模型,采用FLUENT软件模拟了地铁列车在不同速度、不同开门方案下,排烟所需时间及车厢内外压强分布.结果表明,列车车门开度0.07m、车速为30 km/h时,能够快速、有效地排出烟雾.在深圳地铁“世界之窗-赤湾”2号线对数值分析结果进行了试验验证.试验结果与数值分析结果吻合,表明该应急排烟模式的数值分析方法具有较高精度.

Optimizing prescribed fire allocation for managing fire risk in central Catalonia.

Science.gov (United States)

Alcasena, Fermín J; Ager, Alan A; Salis, Michele; Day, Michelle A; Vega-Garcia, Cristina

2018-04-15

We used spatial optimization to allocate and prioritize prescribed fire treatments in the fire-prone Bages County, central Catalonia (northeastern Spain). The goal of this study was to identify suitable strategic locations on forest lands for fuel treatments in order to: 1) disrupt major fire movements, 2) reduce ember emissions, and 3) reduce the likelihood of large fires burning into residential communities. We first modeled fire spread, hazard and exposure metrics under historical extreme fire weather conditions, including node influence grid for surface fire pathways, crown fraction burned and fire transmission to residential structures. Then, we performed an optimization analysis on individual planning areas to identify production possibility frontiers for addressing fire exposure and explore alternative prescribed fire treatment configurations. The results revealed strong trade-offs among different fire exposure metrics, showed treatment mosaics that optimize the allocation of prescribed fire, and identified specific opportunities to achieve multiple objectives. Our methods can contribute to improving the efficiency of prescribed fire treatment investments and wildfire management programs aimed at creating fire resilient ecosystems, facilitating safe and efficient fire suppression, and safeguarding rural communities from catastrophic wildfires. The analysis framework can be used to optimally allocate prescribed fire in other fire-prone areas within the Mediterranean region and elsewhere. Copyright © 2017 Elsevier B.V. All rights reserved.

Enhanced Fire Events Database to Support Fire PRA

International Nuclear Information System (INIS)

Baranowsky, Patrick; Canavan, Ken; St. Germain, Shawn

2010-01-01

This paper provides a description of the updated and enhanced Fire Events Data Base (FEDB) developed by the Electric Power Research Institute (EPRI) in cooperation with the U.S. Nuclear Regulatory Commission (NRC). The FEDB is the principal source of fire incident operational data for use in fire PRAs. It provides a comprehensive and consolidated source of fire incident information for nuclear power plants operating in the U.S. The database classification scheme identifies important attributes of fire incidents to characterize their nature, causal factors, and severity consistent with available data. The database provides sufficient detail to delineate important plant specific attributes of the incidents to the extent practical. A significant enhancement to the updated FEDB is the reorganization and refinement of the database structure and data fields and fire characterization details added to more rigorously capture the nature and magnitude of the fire and damage to the ignition source and nearby equipment and structures.

Fire Behavior (FB)

Science.gov (United States)

Robert E. Keane

2006-01-01

The Fire Behavior (FB) method is used to describe the behavior of the fire and the ambient weather and fuel conditions that influence the fire behavior. Fire behavior methods are not plot based and are collected by fire event and time-date. In general, the fire behavior data are used to interpret the fire effects documented in the plot-level sampling. Unlike the other...

Detection and Characterization of Low Temperature Peat Fires during the 2015 Fire Catastrophe in Indonesia Using a New High-Sensitivity Fire Monitoring Satellite Sensor (FireBird).

Science.gov (United States)

Atwood, Elizabeth C; Englhart, Sandra; Lorenz, Eckehard; Halle, Winfried; Wiedemann, Werner; Siegert, Florian

2016-01-01

Vast and disastrous fires occurred on Borneo during the 2015 dry season, pushing Indonesia into the top five carbon emitting countries. The region was affected by a very strong El Niño-Southern Oscillation (ENSO) climate phenomenon, on par with the last severe event in 1997/98. Fire dynamics in Central Kalimantan were investigated using an innovative sensor offering higher sensitivity to a wider range of fire intensities at a finer spatial resolution (160 m) than heretofore available. The sensor is onboard the TET-1 satellite, part of the German Aerospace Center (DLR) FireBird mission. TET-1 images (acquired every 2-3 days) from the middle infrared were used to detect fires continuously burning for almost three weeks in the protected peatlands of Sebangau National Park as well as surrounding areas with active logging and oil palm concessions. TET-1 detection capabilities were compared with MODIS active fire detection and Landsat burned area algorithms. Fire dynamics, including fire front propagation speed and area burned, were investigated. We show that TET-1 has improved detection capabilities over MODIS in monitoring low-intensity peatland fire fronts through thick smoke and haze. Analysis of fire dynamics revealed that the largest burned areas resulted from fire front lines started from multiple locations, and the highest propagation speeds were in excess of 500 m/day (all over peat > 2m deep). Fires were found to occur most often in concessions that contained drainage infrastructure but were not cleared prior to the fire season. Benefits of implementing this sensor system to improve current fire management techniques are discussed. Near real-time fire detection together with enhanced fire behavior monitoring capabilities would not only improve firefighting efforts, but also benefit analysis of fire impact on tropical peatlands, greenhouse gas emission estimations as well as mitigation measures to reduce severe fire events in the future.

Fire-driven alien invasion in a fire-adapted ecosystem

Science.gov (United States)

Keeley, Jon E.; Brennan, Teresa J.

2012-01-01

Disturbance plays a key role in many alien plant invasions. However, often the main driver of invasion is not disturbance per se but alterations in the disturbance regime. In some fire-adapted shrublands, the community is highly resilient to infrequent, high-intensity fires, but changes in the fire regime that result in shorter fire intervals may make these communities more susceptible to alien plant invasions. This study examines several wildfire events that resulted in short fire intervals in California chaparral shrublands. In one study, we compared postfire recovery patterns in sites with different prefire stand ages (3 and 24 years), and in another study we compared sites that had burned once in four years with sites that had burned twice in this period. The population size of the dominant native shrub Adenostoma fasciculatum was drastically reduced following fire in the 3-year sites relative to the 24-year sites. The 3-year sites had much greater alien plant cover and significantly lower plant diversity than the 24-year sites. In a separate study, repeat fires four years apart on the same sites showed that annual species increased significantly after the second fire, and alien annuals far outnumbered native annuals. Aliens included both annual grasses and annual forbs and were negatively correlated with woody plant cover. Native woody species regenerated well after the first fire but declined after the second fire, and one obligate seeding shrub was extirpated from two sites by the repeat fires. It is concluded that some fire-adapted shrublands are vulnerable to changes in fire regime, and this can lead to a loss of native diversity and put the community on a trajectory towards type conversion from a woody to an herbaceous system. Such changes result in alterations in the proportion of natives to non-natives, changes in functional types from deeply rooted shrubs to shallow rooted grasses and forbs, increased fire frequency due to the increase in fine fuels

Fire-driven alien invasion in a fire-adapted ecosystem.

Science.gov (United States)

Keeley, Jon E; Brennan, Teresa J

2012-08-01

Disturbance plays a key role in many alien plant invasions. However, often the main driver of invasion is not disturbance per se but alterations in the disturbance regime. In some fire-adapted shrublands, the community is highly resilient to infrequent, high-intensity fires, but changes in the fire regime that result in shorter fire intervals may make these communities more susceptible to alien plant invasions. This study examines several wildfire events that resulted in short fire intervals in California chaparral shrublands. In one study, we compared postfire recovery patterns in sites with different prefire stand ages (3 and 24 years), and in another study we compared sites that had burned once in four years with sites that had burned twice in this period. The population size of the dominant native shrub Adenostoma fasciculatum was drastically reduced following fire in the 3-year sites relative to the 24-year sites. The 3-year sites had much greater alien plant cover and significantly lower plant diversity than the 24-year sites. In a separate study, repeat fires four years apart on the same sites showed that annual species increased significantly after the second fire, and alien annuals far outnumbered native annuals. Aliens included both annual grasses and annual forbs and were negatively correlated with woody plant cover. Native woody species regenerated well after the first fire but declined after the second fire, and one obligate seeding shrub was extirpated from two sites by the repeat fires. It is concluded that some fire-adapted shrublands are vulnerable to changes in fire regime, and this can lead to a loss of native diversity and put the community on a trajectory towards type conversion from a woody to an herbaceous system. Such changes result in alterations in the proportion of natives to non-natives, changes in functional types from deeply rooted shrubs to shallow rooted grasses and forbs, increased fire frequency due to the increase in fine fuels

Post-fire vegetation and fuel development influences fire severity patterns in reburns.

Science.gov (United States)

Coppoletta, Michelle; Merriam, Kyle E; Collins, Brandon M

2016-04-01

In areas where fire regimes and forest structure have been dramatically altered, there is increasing concern that contemporary fires have the potential to set forests on a positive feedback trajectory with successive reburns, one in which extensive stand-replacing fire could promote more stand-replacing fire. Our study utilized an extensive set of field plots established following four fires that occurred between 2000 and 2010 in the northern Sierra Nevada, California, USA that were subsequently reburned in 2012. The information obtained from these field plots allowed for a unique set of analyses investigating the effect of vegetation, fuels, topography, fire weather, and forest management on reburn severity. We also examined the influence of initial fire severity and time since initial fire on influential predictors of reburn severity. Our results suggest that high- to moderate-severity fire in the initial fires led to an increase in standing snags and shrub vegetation, which in combination with severe fire weather promoted high-severity fire effects in the subsequent reburn. Although fire behavior is largely driven by weather, our study demonstrates that post-fire vegetation composition and structure are also important drivers of reburn severity. In the face of changing climatic regimes and increases in extreme fire weather, these results may provide managers with options to create more fire-resilient ecosystems. In areas where frequent high-severity fire is undesirable, management activities such as thinning, prescribed fire, or managed wildland fire can be used to moderate fire behavior not only prior to initial fires, but also before subsequent reburns.

Fire intensity impacts on post-fire temperate coniferous forest net primary productivity

Science.gov (United States)

Sparks, Aaron M.; Kolden, Crystal A.; Smith, Alistair M. S.; Boschetti, Luigi; Johnson, Daniel M.; Cochrane, Mark A.

2018-02-01

Fire is a dynamic ecological process in forests and impacts the carbon (C) cycle through direct combustion emissions, tree mortality, and by impairing the ability of surviving trees to sequester carbon. While studies on young trees have demonstrated that fire intensity is a determinant of post-fire net primary productivity, wildland fires on landscape to regional scales have largely been assumed to either cause tree mortality, or conversely, cause no physiological impact, ignoring the impacted but surviving trees. Our objective was to understand how fire intensity affects post-fire net primary productivity in conifer-dominated forested ecosystems on the spatial scale of large wildland fires. We examined the relationships between fire radiative power (FRP), its temporal integral (fire radiative energy - FRE), and net primary productivity (NPP) using 16 years of data from the MOderate Resolution Imaging Spectrometer (MODIS) for 15 large fires in western United States coniferous forests. The greatest NPP post-fire loss occurred 1 year post-fire and ranged from -67 to -312 g C m-2 yr-1 (-13 to -54 %) across all fires. Forests dominated by fire-resistant species (species that typically survive low-intensity fires) experienced the lowest relative NPP reductions compared to forests with less resistant species. Post-fire NPP in forests that were dominated by fire-susceptible species were not as sensitive to FRP or FRE, indicating that NPP in these forests may be reduced to similar levels regardless of fire intensity. Conversely, post-fire NPP in forests dominated by fire-resistant and mixed species decreased with increasing FRP or FRE. In some cases, this dose-response relationship persisted for more than a decade post-fire, highlighting a legacy effect of fire intensity on post-fire C dynamics in these forests.

A Method of Fire Scenarios Identification in a Consolidated Fire Risk Analysis

International Nuclear Information System (INIS)

Lim, Ho Gon; Han, Sang Hoon; Yang, Joon Eon

2010-01-01

Conventional fire PSA consider only two cases of fire scenarios, that is one for fire without propagation and the other for single propagation to neighboring compartment. Recently, a consolidated fire risk analysis using single fault tree (FT) was developed. However, the fire scenario identification in the new method is similar to conventional fire analysis method. The present study develops a new method of fire scenario identification in a consolidated fire risk analysis method. An equation for fire propagation is developed to identify fire scenario and a mapping method of fire scenarios into internal event risk model is discussed. Finally, an algorithm for automatic program is suggested

Fire and fire ecology: Concepts and principles

Science.gov (United States)

Mark A. Cochrane; Kevin C. Ryan

2009-01-01

Fire has been central to terrestrial life ever since early anaerobic microorganisms poisoned the atmosphere with oxygen and multicellular plant life moved onto land. The combination of fuels, oxygen, and heat gave birth to fire on Earth. Fire is not just another evolutionary challenge that life needed to overcome, it is, in fact, a core ecological process across much...

Forest fires

International Nuclear Information System (INIS)

Fuller, M.

1991-01-01

This book examines the many complex and sensitive issues relating to wildland fires. Beginning with an overview of the fires of 1980s, the book discusses the implications of continued drought and considers the behavior of wildland fires, from ignition and spread to spotting and firestorms. Topics include the effects of weather, forest fuels, fire ecology, and the effects of fire on plants and animals. In addition, the book examines firefighting methods and equipment, including new minimum impact techniques and compressed air foam; prescribed burning; and steps that can be taken to protect individuals and human structures. A history of forest fire policies in the U.S. and a discussion of solutions to fire problems around the world completes the coverage. With one percent of the earth's surface burning every year in the last decade, this is a penetrating book on a subject of undeniable importance

Detection and Characterization of Low Temperature Peat Fires during the 2015 Fire Catastrophe in Indonesia Using a New High-Sensitivity Fire Monitoring Satellite Sensor (FireBird)

Science.gov (United States)

Atwood, Elizabeth C.; Englhart, Sandra; Lorenz, Eckehard; Halle, Winfried; Wiedemann, Werner; Siegert, Florian

2016-01-01

Vast and disastrous fires occurred on Borneo during the 2015 dry season, pushing Indonesia into the top five carbon emitting countries. The region was affected by a very strong El Niño-Southern Oscillation (ENSO) climate phenomenon, on par with the last severe event in 1997/98. Fire dynamics in Central Kalimantan were investigated using an innovative sensor offering higher sensitivity to a wider range of fire intensities at a finer spatial resolution (160 m) than heretofore available. The sensor is onboard the TET-1 satellite, part of the German Aerospace Center (DLR) FireBird mission. TET-1 images (acquired every 2–3 days) from the middle infrared were used to detect fires continuously burning for almost three weeks in the protected peatlands of Sebangau National Park as well as surrounding areas with active logging and oil palm concessions. TET-1 detection capabilities were compared with MODIS active fire detection and Landsat burned area algorithms. Fire dynamics, including fire front propagation speed and area burned, were investigated. We show that TET-1 has improved detection capabilities over MODIS in monitoring low-intensity peatland fire fronts through thick smoke and haze. Analysis of fire dynamics revealed that the largest burned areas resulted from fire front lines started from multiple locations, and the highest propagation speeds were in excess of 500 m/day (all over peat > 2m deep). Fires were found to occur most often in concessions that contained drainage infrastructure but were not cleared prior to the fire season. Benefits of implementing this sensor system to improve current fire management techniques are discussed. Near real-time fire detection together with enhanced fire behavior monitoring capabilities would not only improve firefighting efforts, but also benefit analysis of fire impact on tropical peatlands, greenhouse gas emission estimations as well as mitigation measures to reduce severe fire events in the future. PMID:27486664

Browns Ferry fire

International Nuclear Information System (INIS)

Harkleroad, J.R.

1983-01-01

A synopsis of the March 22, 1975 fire at Browns Ferry Nuclear Plant is discussed. Emphasis is placed on events prior to and during the fire. How the fire started, fire fighting activities, fire and smoke development, and restoration activities are discussed

Overview of the 2013 FireFlux II grass fire field experiment

Science.gov (United States)

C.B. Clements; B. Davis; D. Seto; J. Contezac; A. Kochanski; J.-B. Fillipi; N. Lareau; B. Barboni; B. Butler; S. Krueger; R. Ottmar; R. Vihnanek; W.E. Heilman; J. Flynn; M.A. Jenkins; J. Mandel; C. Teske; D. Jimenez; J. O' Brien; B. Lefer

2014-01-01

In order to better understand the dynamics of fire-atmosphere interactions and the role of micrometeorology on fire behaviour the FireFlux campaign was conducted in 2006 on a coastal tall-grass prairie in southeast Texas, USA. The FireFlux campaign dataset has become the international standard for evaluating coupled fire-atmosphere model systems. While FireFlux is one...

Causal Analysis to a Subway Accident: A Comparison of STAMP and RAIB

Directory of Open Access Journals (Sweden)

Zhou Yao

2018-01-01

Full Text Available Accident investigation and analysis after the accident, vital to prevent the occurrence of similar accident and improve the safety of the system. Different methods led to a different understanding of the accident. In this paper, a subway accident was analysed with a systemic accident analysis model – STAMP (System-Theoretic Accident Modelling and Processes. The hierarchical safety control structure was obtained, and the system-level safety constraints were obtained, controllers of the physical layer were analysed one by one, and put forward the relevant safety requirements and constraints, the dynamic analysis of the structure of the safety control is carried out, and the targeted recommendations are pointed out. In comparison with the analysis results obtained by the Rail Accident Investigation Branch (RAIB. Some useful findings have been concluded. STAMP treats safety as a control problem and reduces or eliminates causes of the accident from the controlling perspective. Whereas RAIB obtains causes of the accident by analysing the sequence of events related to the accident and reasons of these events, then chooses one(or moreevent(s as the immediate cause and some of the key events as causal factors. RAIB analysis is based on the sequential event models, but STAMP analysis provides us with a holistic, dynamic way to control system to maintain safety.

Fire models for assessment of nuclear power plant fires

International Nuclear Information System (INIS)

Nicolette, V.F.; Nowlen, S.P.

1989-01-01

This paper reviews the state-of-the-art in available fire models for the assessment of nuclear power plants fires. The advantages and disadvantages of three basic types of fire models (zone, field, and control volume) and Sandia's experience with these models will be discussed. It is shown that the type of fire model selected to solve a particular problem should be based on the information that is required. Areas of concern which relate to all nuclear power plant fire models are identified. 17 refs., 6 figs

Fire severity and ecosytem responses following crown fires in California shrublands.

Science.gov (United States)

Keeley, Jon E; Brennan, Teresa; Pfaff, Anne H

2008-09-01

Chaparral shrublands burn in large high-intensity crown fires. Managers interested in how these wildfires affect ecosystem processes generally rely on surrogate measures of fire intensity known as fire severity metrics. In shrublands burned in the autumn of 2003, a study of 250 sites investigated factors determining fire severity and ecosystem responses. Using structural equation modeling we show that stand age, prefire shrub density, and the shortest interval of the prior fire history had significant direct effects on fire severity, explaining > 50% of the variation in severity. Fire severity per se is of interest to resource managers primarily because it is presumed to be an indicator of important ecosystem processes such as vegetative regeneration, community recovery, and erosion. Fire severity contributed relatively little to explaining patterns of regeneration after fire. Two generalizations can be drawn: fire severity effects are mostly shortlived, i.e., by the second year they are greatly diminished, and fire severity may have opposite effects on different functional types. Species richness exhibited a negative relationship to fire severity in the first year, but fire severity impacts were substantially less in the second postfire year and varied by functional type. Much of this relationship was due to alien plants that are sensitive to high fire severity; at all scales from 1 to 1000 m2, the percentage of alien species in the postfire flora declined with increased fire severity. Other aspects of disturbance history are also important determinants of alien cover and richness as both increased with the number of times the site had burned and decreased with time since last fire. A substantial number of studies have shown that remote-sensing indices are correlated with field measurements of fire severity. Across our sites, absolute differenced normalized burn ratio (dNBR) was strongly correlated with field measures of fire severity and with fire history at a

Fire Extinguisher Training for Fire Watch and Designated Workers, Course 9893

Energy Technology Data Exchange (ETDEWEB)

Harris, Jimmy D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2016-04-19

At Los Alamos National Laboratory (LANL), all workers must be aware of LANL fire protection policies and be trained on what to do in the event of a fire. This course, Fire Extinguisher Training for Fire Watch and Designated Workers (#9893), provides awareness-level and hands-on training for fire watch personnel and designated workers. Fire watch personnel and designated workers are appointed by line management and must receive both awareness-level training and hands-on training in the use of portable fire extinguishers to extinguish an incipient-stage fire. This training meets the requirements of the Occupational Safety and Health Administration (OSHA) Code of Federal Regulations (CFR) 29 CFR 1910.157, Portable Fire Extinguishers, and Procedure (P) 101-26, Welding, Cutting, and Other Spark-/Flame-Producing Operations.

Fire Extinguisher Designated Worker and Fire Watch: Self-Study Course 15672

Energy Technology Data Exchange (ETDEWEB)

Harris, Jimmy D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2016-07-08

At Los Alamos National Laboratory (LANL), all workers must be aware of LANL fire protection policies and be trained on what to do in the event of a fire. This course, Fire Extinguisher Training for Fire Watch and Designated Workers (#9893), provides awareness-level and hands-on training for fire watch personnel and designated workers. Fire watch personnel and designated workers are appointed by line management and must receive both awareness-level training and hands-on training in the use of portable fire extinguishers to extinguish an incipient-stage fire. This training meets the requirements of the Occupational Safety and Health Administration (OSHA) Code of Federal Regulations (CFR) 29 CFR 1910.157, Portable Fire Extinguishers, and Procedure (P) 101-26, Welding, Cutting, and Other Spark-/Flame-Producing Operations.

Risk Assessment of the Main Control Room Fire Using Fire Simulations

International Nuclear Information System (INIS)

Kang, Dae Il; Kim, Kilyoo; Jang, Seung Cheol

2013-01-01

KAERI is performing a fire PSA for a reference plant, Ulchin Unit 3, as part of developing the Korean site risk profile (KSRP). Fire simulations of the MCR fire were conducted using the CFAST (Consolidated Fire Growth and Smoke Transport) model and FDS (fire dynamic simulator) to improve the uncertainty in the MCR fire risk analysis. Using the fire simulation results, the MCR abandonment risk was evaluated. Level 1 PSA (probabilistic safety assessment) results of Ulchin Unit 3 using the EPRI PRA (probabilistic risk assessment) implementation guide showed that the MCR (main control room) fire was the main contributor to the core damage frequency. Recently, U. S. NRC and EPRI developed NUREG/CR-6850 to provide state-of-the-art methods, tools, and data for the conduct of a fire PSA for a commercial NPP

Optimizing a desirable fare structure for a bus-subway corridor.

Science.gov (United States)

Liu, Bing-Zheng; Ge, Ying-En; Cao, Kai; Jiang, Xi; Meng, Lingyun; Liu, Ding; Gao, Yunfeng

2017-01-01

This paper aims to optimize a desirable fare structure for the public transit service along a bus-subway corridor with the consideration of those factors related to equity in trip, including travel distance and comfort level. The travel distance factor is represented by the distance-based fare strategy, which is an existing differential strategy. The comfort level one is considered in the area-based fare strategy which is a new differential strategy defined in this paper. Both factors are referred to by the combined fare strategy which is composed of distance-based and area-based fare strategies. The flat fare strategy is applied to determine a reference level of social welfare and obtain the general passenger flow along transit lines, which is used to divide areas or zones along the corridor. This problem is formulated as a bi-level program, of which the upper level maximizes the social welfare and the lower level capturing traveler choice behavior is a variable-demand stochastic user equilibrium assignment model. A genetic algorithm is applied to solve the bi-level program while the method of successive averages is adopted to solve the lower-level model. A series of numerical experiments are carried out to illustrate the performance of the models and solution methods. Numerical results indicate that all three differential fare strategies play a better role in enhancing the social welfare than the flat fare strategy and that the fare structure under the combined fare strategy generates the highest social welfare and the largest resulting passenger demand, which implies that the more equity factors a differential fare strategy involves the more desirable fare structure the strategy has.

Optimizing a desirable fare structure for a bus-subway corridor

Science.gov (United States)

Liu, Bing-Zheng; Ge, Ying-En; Cao, Kai; Jiang, Xi; Meng, Lingyun; Liu, Ding; Gao, Yunfeng

2017-01-01

This paper aims to optimize a desirable fare structure for the public transit service along a bus-subway corridor with the consideration of those factors related to equity in trip, including travel distance and comfort level. The travel distance factor is represented by the distance-based fare strategy, which is an existing differential strategy. The comfort level one is considered in the area-based fare strategy which is a new differential strategy defined in this paper. Both factors are referred to by the combined fare strategy which is composed of distance-based and area-based fare strategies. The flat fare strategy is applied to determine a reference level of social welfare and obtain the general passenger flow along transit lines, which is used to divide areas or zones along the corridor. This problem is formulated as a bi-level program, of which the upper level maximizes the social welfare and the lower level capturing traveler choice behavior is a variable-demand stochastic user equilibrium assignment model. A genetic algorithm is applied to solve the bi-level program while the method of successive averages is adopted to solve the lower-level model. A series of numerical experiments are carried out to illustrate the performance of the models and solution methods. Numerical results indicate that all three differential fare strategies play a better role in enhancing the social welfare than the flat fare strategy and that the fare structure under the combined fare strategy generates the highest social welfare and the largest resulting passenger demand, which implies that the more equity factors a differential fare strategy involves the more desirable fare structure the strategy has. PMID:28981508

Fire characteristics associated with firefighter injury on large federal wildland fires.

Science.gov (United States)

Britton, Carla; Lynch, Charles F; Torner, James; Peek-Asa, Corinne

2013-02-01

Wildland fires present many injury hazards to firefighters. We estimate injury rates and identify fire-related factors associated with injury. Data from the National Interagency Fire Center from 2003 to 2007 provided the number of injuries in which the firefighter could not return to his or her job assignment, person-days worked, and fire characteristics (year, region, season, cause, fuel type, resistance to control, and structures destroyed). We assessed fire-level risk factors of having at least one reported injury using logistic regression. Negative binomial regression was used to examine incidence rate ratios associated with fire-level risk factors. Of 867 fires, 9.5% required the most complex management and 24.7% required the next-highest level of management. Fires most often occurred in the western United States (82.8%), during the summer (69.6%), caused by lightening (54.9%). Timber was the most frequent fuel source (40.2%). Peak incident management level, person-days of exposure, and the fire's resistance to control were significantly related to the odds of a fire having at least one reported injury. However, the most complex fires had a lower injury incidence rate than less complex fires. Although fire complexity and the number of firefighters were associated with the risk for at least one reported injury, the more experienced and specialized firefighting teams had lower injury incidence. Copyright © 2013 Elsevier Inc. All rights reserved.

Fire Research Enclosure

Data.gov (United States)

Federal Laboratory Consortium — FUNCTION: Simulates submarine fires, enclosed aircraft fires, and fires in enclosures at shore facilities .DESCRIPTION: FIRE I is a pressurizable, 324 cu m(11,400 cu...

Fire protection for launch facilities using machine vision fire detection

Science.gov (United States)

Schwartz, Douglas B.

1993-02-01

Fire protection of critical space assets, including launch and fueling facilities and manned flight hardware, demands automatic sensors for continuous monitoring, and in certain high-threat areas, fast-reacting automatic suppression systems. Perhaps the most essential characteristic for these fire detection and suppression systems is high reliability; in other words, fire detectors should alarm only on actual fires and not be falsely activated by extraneous sources. Existing types of fire detectors have been greatly improved in the past decade; however, fundamental limitations of their method of operation leaves open a significant possibility of false alarms and restricts their usefulness. At the Civil Engineering Laboratory at Tyndall Air Force Base in Florida, a new type of fire detector is under development which 'sees' a fire visually, like a human being, and makes a reliable decision based on known visual characteristics of flames. Hardware prototypes of the Machine Vision (MV) Fire Detection System have undergone live fire tests and demonstrated extremely high accuracy in discriminating actual fires from false alarm sources. In fact, this technology promises to virtually eliminate false activations. This detector could be used to monitor fueling facilities, launch towers, clean rooms, and other high-value and high-risk areas. Applications can extend to space station and in-flight shuttle operations as well; fiber optics and remote camera heads enable the system to see around obstructed areas and crew compartments. The capability of the technology to distinguish fires means that fire detection can be provided even during maintenance operations, such as welding.

34 CFR 668.49 - Institutional fire safety policies and fire statistics.

Science.gov (United States)

2010-07-01

... 34 Education 3 2010-07-01 2010-07-01 false Institutional fire safety policies and fire statistics... fire statistics. (a) Additional definitions that apply to this section. Cause of fire: The factor or...; however, it does not include indirect loss, such as business interruption. (b) Annual fire safety report...

All fired up

CERN Multimedia

CERN Bulletin

2013-01-01

Members of the Directorate and their support staff took part in a fire-fighting course organised by the CERN Fire Brigade just before the end-of-year break.  The Bulletin takes a look at the fire-fighting training on offer at CERN.   At CERN the risk of fire can never be under-estimated. In order to train personnel in the use of fire extinguishers, CERN's fire training centre in Prévessin acquired a fire-simulation platform in 2012. On the morning of 17 December 2012, ten members of the CERN directorate and their support staff tried out the platform, following in the footsteps of 400 other members of the CERN community who had already attended the course. The participants were welcomed to the training centre by Gilles Colin, a fire-fighter and instructor, who gave them a 30-minute introduction to general safety and the different types of fire and fire extinguishers, followed by an hour of practical instruction in the simulation facility. There they were able to pract...

Corrosion control by limestone immersion into the hot water heat-storage tank. Case history of air-conditioning systems of Sapporo city subway stations; Sekkaiseki shinsekiho ni yoru chikunetsu onsui keito no boshoku koka. Sapporoshi chikatetsu kakueki no kucho setsubi no jirei

Energy Technology Data Exchange (ETDEWEB)

Kishi, M. [Sapporo City Transportation Bureau, Sapporo (Japan); Okumura, J. [Hokkaido Nikken Sekkei Ltd., Sapporo (Japan); Sakai, Y.; Shiiya, O. [Takasago Thermal Engineering Co. Ltd., Tokyo (Japan)

1995-06-05

Limestone immersion into heat-storage water tanks is a method for improving the water quality so as to encrust inner surface of piping by corrosion-preventive calcium carbonate film. For air-conditioning of Support city subway stations, heat-storing heat-pump systems with heat recovery from exhaust air have been introduced and developed for energy saving along with expansion of the subway routes. Inner surfaces of the heat-storage water tanks of all stations are coated with FRP-lining, therefore, some corrosion-preventive chemicals had been dosed from the starting up. However, the storage waters of all stations turned to red because of continuity of the piping corrosion. Instead of dosing chemicals, the limestone immersion method station. Thanks to His method, excellent results were obtained in a short period contributing control of the piping corrosion together with the red water fading. 14 figs., 1 tab.

Tunnel fire dynamics

CERN Document Server

Ingason, Haukur; Lönnermark, Anders

2015-01-01

This book covers a wide range of issues in fire safety engineering in tunnels, describes the phenomena related to tunnel fire dynamics, presents state-of-the-art research, and gives detailed solutions to these major issues. Examples for calculations are provided. The aim is to significantly improve the understanding of fire safety engineering in tunnels. Chapters on fuel and ventilation control, combustion products, gas temperatures, heat fluxes, smoke stratification, visibility, tenability, design fire curves, heat release, fire suppression and detection, CFD modeling, and scaling techniques all equip readers to create their own fire safety plans for tunnels. This book should be purchased by any engineer or public official with responsibility for tunnels. It would also be of interest to many fire protection engineers as an application of evolving technical principles of fire safety.

Characterization of potential fire regimes: applying landscape ecology to fire management in Mexico

Science.gov (United States)

Jardel, E.; Alvarado, E.; Perez-Salicrup, D.; Morfín-Rios, J.

2013-05-01

Knowledge and understanding of fire regimes is fundamental to design sound fire management practices. The high ecosystem diversity of Mexico offers a great challenge to characterize the fire regime variation at the landscape level. A conceptual model was developed considering the main factors controlling fire regimes: climate and vegetation cover. We classified landscape units combining bioclimatic zones from the Holdridge life-zone system and actual vegetation cover. Since bioclimatic conditions control primary productivity and biomass accumulation (potential fuel), each landscape unit was considered as a fuel bed with a particular fire intensity and behavior potential. Climate is also a determinant factor of post-fire recovery rates of fuel beds, and climate seasonality (length of the dry and wet seasons) influences fire probability (available fuel and ignition efficiency). These two factors influence potential fire frequency. Potential fire severity can be inferred from fire frequency, fire intensity and behavior, and vegetation composition and structure. Based in the conceptual model, an exhaustive literature review and expert opinion, we developed rules to assign a potential fire regime (PFR) defined by frequency, intensity and severity (i.e. fire regime) to each bioclimatic-vegetation landscape unit. Three groups and eight types of potential fire regimes were identified. In Group A are fire-prone ecosystems with frequent low severity surface fires in grasslands (PFR type I) or forests with long dry season (II) and infrequent high-severity fires in chaparral (III), wet temperate forests (IV, fire restricted by humidity), and dry temperate forests (V, fire restricted by fuel recovery rate). Group B includes fire-reluctant ecosystems with very infrequent or occasional mixed severity surface fires limited by moisture in tropical rain forests (VI) or fuel availability in seasonally dry tropical forests (VII). Group C and PFR VIII include fire-free environments

The role of fuels for understanding fire behavior and fire effects

Science.gov (United States)

E. Louise Loudermilk; J. Kevin Hiers; Joseph J. O' Brien

2018-01-01

Fire ecology, which has emerged as a critical discipline, links the complex interactions that occur between fire regimes and ecosystems. The ecology of fuels, a first principle in fire ecology, identifies feedbacks between vegetation and fire behavior-a cyclic process that starts with fuels influencing fire behavior, which in turn governs patterns of postfire...

Fire Problems in High-Rise Buildings. California Fire Service Training Program.

Science.gov (United States)

California State Dept. of Education, Sacramento. Bureau of Industrial Education.

Resulting from a conference concerned with high-rise fire problems, this manual has been prepared as a fire department training manual and as a reference for students enrolled in fire service training courses. Information is provided for topics dealing with: (1) Typical Fire Problems in High-Rise Buildings, (2) Heat, (3) Smoke and Fire Gases, (4)…

Forest fires in Pennsylvania.

Science.gov (United States)

Donald A. Haines; William A. Main; Eugene F. McNamara

1978-01-01

Describes factors that contribute to forest fires in Pennsylvania. Includes an analysis of basic statistics; distribution of fires during normal, drought, and wet years; fire cause, fire activity by day-of-week; multiple-fire day; and fire climatology.

Fire safety assessment for the fire areas of the nuclear power plant using fire model CFAST

International Nuclear Information System (INIS)

Lee, Yoon Hwan; Yang, Joon Eon; Kim, Jong Hoon

2005-03-01

Now the deterministic analysis results for the cable integrity is not given in case of performing the fire PSA. So it is necessary to develop the assessment methodology for the fire growth and propagation. This document is intended to analyze the peak temperature of the upper gas layer using the fire modeling code, CFAST, to evaluate the integrity of the cable located on the dominant pump rooms, and to assess the CCDP(Conditional Core Damage Probability) using the results of the cable integrity. According to the analysis results, the cable integrity of the pump rooms is maintained and CCDP is reduced about two times than the old one. Accordingly, the fire safety assessment for the dominant fire areas using the fire modeling code will capable to reduce the uncertainty and to develop a more realistic model

Impacts of fire, fire-fighting chemicals and post-fire stabilization techniques on the soil-plant system

OpenAIRE

Fernández Fernández, María

2017-01-01

Forest fires, as well as fire-fighting chemicals, greatly affect the soil-plant system causing vegetation loss, alterations of soil properties and nutrient losses through volatilization, leaching and erosion. Soil recovery after fires depends on the regeneration of the vegetation cover, which protects the soil and prevents erosion. Fire-fighting chemicals contain compounds potentially toxic for plants and soil organisms, and thus their use might hamper the regeneration of burnt ecosystems. In...

MRTA Blue Line Bangkok: power supply for Thailand's first subway system; MRTA Blue Line Bangkok: Energieversorgung fuer die erste U-Bahn in Thailand

Energy Technology Data Exchange (ETDEWEB)

Menter, F.E. [Siemens AG, Erlangen (Germany)

2006-07-01

Thailand's first subway system has commenced revenue operation during summer of 2004. Since the system opening, the power supply system has provided traction and station power for the operation of this mass rapid transit system, which has been widely accepted by the public. The system combines service-proven and state-of-the-art components and subsystems from Europe and Asia. Highest consideration has been given to reliability, serviceability and availability. The project management successfully mastered several challenges, stemming from the immense time pressure, the nature of the project's stakeholders and the variety of the many, multinational interface partners. (orig.)

Fire Propagation Tracing Model in the Explicit Treatment of Events of Fire PSA

International Nuclear Information System (INIS)

Lim, Ho Gon; Han, Sang Hoon; Yang, Jun Eon

2010-01-01

The fire propagation model in a fire PSA has not been considered analytically instead a simplified analyst's intuition was used to consider the fire propagation path. A fire propagation equation is developed to trace all the propagation paths in the fire area in which a zone is defined to identify various fire ignition sources. An initiation of fire is assumed to take place in a zone. Then, the propagation is modeled with a Boolean equation. Since the explicit fire PSA modeling requires an exclusive event set to sum up the..., exclusive event sets are derived from the fire propagation equation. As an example, we show the exclusive set for a 2x3 rectangular fire zone. Also, the applicability the developed fire equation is discussed when the number of zone increases including the limitation of the explicit fire PSA modeling method

Changes in fire weather distributions: effects on predicted fire behavior

Science.gov (United States)

Lucy A. Salazar; Larry S. Bradshaw

1984-01-01

Data that represent average worst fire weather for a particular area are used to index daily fire danger; however, they do not account for different locations or diurnal weather changes that significantly affect fire behavior potential. To study the effects that selected changes in weather databases have on computed fire behavior parameters, weather data for the...

Model uncertainty of various settlement estimation methods in shallow tunnels excavation; case study: Qom subway tunnel

Science.gov (United States)

Khademian, Amir; Abdollahipour, Hamed; Bagherpour, Raheb; Faramarzi, Lohrasb

2017-10-01

In addition to the numerous planning and executive challenges, underground excavation in urban areas is always followed by certain destructive effects especially on the ground surface; ground settlement is the most important of these effects for which estimation there exist different empirical, analytical and numerical methods. Since geotechnical models are associated with considerable model uncertainty, this study characterized the model uncertainty of settlement estimation models through a systematic comparison between model predictions and past performance data derived from instrumentation. To do so, the amount of surface settlement induced by excavation of the Qom subway tunnel was estimated via empirical (Peck), analytical (Loganathan and Poulos) and numerical (FDM) methods; the resulting maximum settlement value of each model were 1.86, 2.02 and 1.52 cm, respectively. The comparison of these predicted amounts with the actual data from instrumentation was employed to specify the uncertainty of each model. The numerical model outcomes, with a relative error of 3.8%, best matched the reality and the analytical method, with a relative error of 27.8%, yielded the highest level of model uncertainty.

Survival After Ventricular Fibrillation Cardiac Arrest in the Sao Paulo Metropolitan Subway System: First Successful Targeted Automated External Defibrillator (AED) Program in Latin America.

Science.gov (United States)

Gianotto-Oliveira, Renan; Gonzalez, Maria Margarita; Vianna, Caio Brito; Monteiro Alves, Maurício; Timerman, Sergio; Kalil Filho, Roberto; Kern, Karl B

2015-10-09

Targeted automated external defibrillator (AED) programs have improved survival rates among patients who have an out-of-hospital cardiac arrest (OHCA) in US airports, as well as European and Japanese railways. The Sao Paulo (Brazil) Metro subway carries 4.5 million people per day. A targeted AED program was begun in the Sao Paulo Metro with the objective to improve survival from cardiac arrest. A prospective, longitudinal, observational study of all cardiac arrests in the Sao Paulo Metro was performed from September 2006 through November 2012. This study focused on cardiac arrest by ventricular arrhythmias, and the primary endpoint was survival to hospital discharge with minimal neurological impairment. A total of 62 patients had an initial cardiac rhythm of ventricular fibrillation. Because no data on cardiac arrest treatment or outcomes existed before beginning this project, the first 16 months of the implementation was used as the initial experience and compared with the subsequent 5 years of full operation. Return of spontaneous circulation was not different between the initial 16 months and the subsequent 5 years (6 of 8 [75%] vs. 39 of 54 [72%]; P=0.88). However, survival to discharge was significantly different once the full program was instituted (0 of 8 vs. 23 of 54 [43%]; P=0.001). Implementation of a targeted AED program in the Sao Paulo Metro subway system saved lives. A short interval between arrest and defibrillation was key for good long-term, neurologically intact survival. These results support strategic expansion of targeted AED programs in other large Latin American cities. © 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Assessing fire impacts on the carbon stability of fire-tolerant forests.

Science.gov (United States)

Bennett, Lauren T; Bruce, Matthew J; Machunter, Josephine; Kohout, Michele; Krishnaraj, Saravanan Jangammanaidu; Aponte, Cristina

2017-12-01

The carbon stability of fire-tolerant forests is often assumed but less frequently assessed, limiting the potential to anticipate threats to forest carbon posed by predicted increases in forest fire activity. Assessing the carbon stability of fire-tolerant forests requires multi-indicator approaches that recognize the myriad ways that fires influence the carbon balance, including combustion, deposition of pyrogenic material, and tree death, post-fire decomposition, recruitment, and growth. Five years after a large-scale wildfire in southeastern Australia, we assessed the impacts of low- and high-severity wildfire, with and without prescribed fire (≤10 yr before), on carbon stocks in multiple pools, and on carbon stability indicators (carbon stock percentages in live trees and in small trees, and carbon stocks in char and fuels) in fire-tolerant eucalypt forests. Relative to unburned forest, high-severity wildfire decreased short-term (five-year) carbon stability by significantly decreasing live tree carbon stocks and percentage stocks in live standing trees (reflecting elevated tree mortality), by increasing the percentage of live tree carbon in small trees (those vulnerable to the next fire), and by potentially increasing the probability of another fire through increased elevated fine fuel loads. In contrast, low-severity wildfire enhanced carbon stability by having negligible effects on aboveground stocks and indicators, and by significantly increasing carbon stocks in char and, in particular, soils, indicating pyrogenic carbon accumulation. Overall, recent preceding prescribed fire did not markedly influence wildfire effects on short-term carbon stability at stand scales. Despite wide confidence intervals around mean stock differences, indicating uncertainty about the magnitude of fire effects in these natural forests, our assessment highlights the need for active management of carbon assets in fire-tolerant eucalypt forests under contemporary fire regimes

Humans, Fires, and Forests - Social science applied to fire management

Science.gov (United States)

Hanna J. Cortner; Donald R. Field; Pam Jakes; James D. Buthman

2003-01-01

The 2000 and 2002 fire seasons resulted in increased political scrutiny of the nation's wildland fire threats, and given the fact that millions of acres of lands are still at high risk for future catastrophic fire events, the issues highlighted by the recent fire seasons are not likely to go away any time soon. Recognizing the magnitude of the problem, the...

EPS insulated façade fires from a fire and rescue perspective

Directory of Open Access Journals (Sweden)

Kumm M.

2013-11-01

Full Text Available This paper highlights the challenges the fire and rescue services can meet at façade fires involving EPS insulation during construction and use of a building. The EPS characteristics are discussed in respect to the fire and rescue operation and results from orientating fire tests performed at a fire and rescue services training and test field are presented. Types of evacuation solutions, involving the fire and rescue services, where façade fires can delay or completely rule out the possibilities for safe evacuation, are presented. The restrictions in the Swedish building codes regarding use of combustible insulation are analysed and reflections over the practical problems with following the instructions to keep an EPS insulated façade safe through the building's whole lifespan are made. A number of occurred fires involving EPS are discussed and analysed from a fire and rescue perspective. Finally, recommendations are given for the fire and rescue services and future research fields are proposed.

Using unplanned fires to help suppressing future large fires in Mediterranean forests.

Directory of Open Access Journals (Sweden)

Adrián Regos

Full Text Available Despite the huge resources invested in fire suppression, the impact of wildfires has considerably increased across the Mediterranean region since the second half of the 20th century. Modulating fire suppression efforts in mild weather conditions is an appealing but hotly-debated strategy to use unplanned fires and associated fuel reduction to create opportunities for suppression of large fires in future adverse weather conditions. Using a spatially-explicit fire-succession model developed for Catalonia (Spain, we assessed this opportunistic policy by using two fire suppression strategies that reproduce how firefighters in extreme weather conditions exploit previous fire scars as firefighting opportunities. We designed scenarios by combining different levels of fire suppression efficiency and climatic severity for a 50-year period (2000-2050. An opportunistic fire suppression policy induced large-scale changes in fire regimes and decreased the area burnt under extreme climate conditions, but only accounted for up to 18-22% of the area to be burnt in reference scenarios. The area suppressed in adverse years tended to increase in scenarios with increasing amounts of area burnt during years dominated by mild weather. Climate change had counterintuitive effects on opportunistic fire suppression strategies. Climate warming increased the incidence of large fires under uncontrolled conditions but also indirectly increased opportunities for enhanced fire suppression. Therefore, to shift fire suppression opportunities from adverse to mild years, we would require a disproportionately large amount of area burnt in mild years. We conclude that the strategic planning of fire suppression resources has the potential to become an important cost-effective fuel-reduction strategy at large spatial scale. We do however suggest that this strategy should probably be accompanied by other fuel-reduction treatments applied at broad scales if large-scale changes in fire

Using unplanned fires to help suppressing future large fires in Mediterranean forests.

Science.gov (United States)

Regos, Adrián; Aquilué, Núria; Retana, Javier; De Cáceres, Miquel; Brotons, Lluís

2014-01-01

Despite the huge resources invested in fire suppression, the impact of wildfires has considerably increased across the Mediterranean region since the second half of the 20th century. Modulating fire suppression efforts in mild weather conditions is an appealing but hotly-debated strategy to use unplanned fires and associated fuel reduction to create opportunities for suppression of large fires in future adverse weather conditions. Using a spatially-explicit fire-succession model developed for Catalonia (Spain), we assessed this opportunistic policy by using two fire suppression strategies that reproduce how firefighters in extreme weather conditions exploit previous fire scars as firefighting opportunities. We designed scenarios by combining different levels of fire suppression efficiency and climatic severity for a 50-year period (2000-2050). An opportunistic fire suppression policy induced large-scale changes in fire regimes and decreased the area burnt under extreme climate conditions, but only accounted for up to 18-22% of the area to be burnt in reference scenarios. The area suppressed in adverse years tended to increase in scenarios with increasing amounts of area burnt during years dominated by mild weather. Climate change had counterintuitive effects on opportunistic fire suppression strategies. Climate warming increased the incidence of large fires under uncontrolled conditions but also indirectly increased opportunities for enhanced fire suppression. Therefore, to shift fire suppression opportunities from adverse to mild years, we would require a disproportionately large amount of area burnt in mild years. We conclude that the strategic planning of fire suppression resources has the potential to become an important cost-effective fuel-reduction strategy at large spatial scale. We do however suggest that this strategy should probably be accompanied by other fuel-reduction treatments applied at broad scales if large-scale changes in fire regimes are to be

OECD-FIRE PR02. OECD-FIRE database record structure

International Nuclear Information System (INIS)

Kolar, L.

2005-12-01

In the coding guidelines, the scope, format, and details of any record required to input a real fire event at a nuclear reactor unit to the international OECD-FIRE database are described in detail. The database was set up in the OECD-FIRE-PR02 code

Numerical modeling of the effects of fire-induced convection and fire-atmosphere interactions on wildfire spread and fire plume dynamics

Science.gov (United States)

Sun, Ruiyu

It is possible due to present day computing power to produce a fluid dynamical physically-based numerical solution to wildfire behavior, at least in the research mode. This type of wildfire modeling affords a flexibility and produces details that are not available in either current operational wildfire behavior models or field experiments. However before using these models to study wildfire, validation is necessary, and model results need to be systematically and objectively analyzed and compared to real fires. Plume theory and data from the Meteotron experiment, which was specially designed to provide results from measurements for the theoretical study of a convective plume produced by a high heat source at the ground, are used here to evaluate the fire plume properties simulated by two numerical wildfire models, the Fire Dynamics Simulator or FDS, and the Clark coupled atmosphere-fire model. The study indicates that the FDS produces good agreement with the plume theory and the Meteotron results. The study also suggests that the coupled atmosphere-fire model, a less explicit and ideally less computationally demanding model than the FDS; can produce good agreement, but that the agreement is sensitive to the method of putting the energy released from the fire into the atmosphere. The WFDS (Wildfire and wildland-urban interface FDS), an extension of the FDS to the vegetative fuel, and the Australian grass fire experiments are used to evaluate and improve the UULES-wildfire coupled model. Despite the simple fire parameterization in the UULES-wildfire coupled model, the fireline is fairly well predicted in terms of both shape and location in the simulation of Australian grass fire experiment F19. Finally, the UULES-wildfire coupled model is used to examine how the turbulent flow in the atmospheric boundary layer (ABL) affects the growth of the grass fires. The model fires showed significant randomness in fire growth: Fire spread is not deterministic in the ABL, and a

Fire protection at hot laboratories: Prevention, surveillance and fire-fighting

International Nuclear Information System (INIS)

Chappellier, A.M.

1976-01-01

After pointing out that fire in a hot laboratory can be an important factor contributing to a radioactivity accident, the author briefly recalls the items to be taken into account in a fire hazard analysis. He then describes various important aspects of prevention, detection and fire-fighting which - at the French Commissariat a l'Energie Atomique - are governed by already defined rules or by guidelines which are sufficiently advanced to give a clear idea of the final conclusions to be drawn therefrom. From the point of view protection, the concept of fire sector has been evolved, at hot laboratories, becomes the fire and contamination sector, so as to ensure under all circumstances the containment of any radioactive materials dispersed in the premises on fire. Regarding fire detection, a study should be made on the constraints specific to the facility and liable to affect detector operation. These include ventilation, radiations, neutral or corrosive atmosphere, etc. As regards fire-fighting, two particular aspects are dealt with, namely the question of using water in case of fire and action to be taken concerning ventilation. A practical example - the protection of a ventilation system - is described. In conclusion the paper refers to the need for a thorough analysis specific to each hot laboratory, and to the importance of preparing an operational plan so as to avoid any dangerous improvisations in case of an accident. (author)

The contribution of natural fire management to wilderness fire science

Science.gov (United States)

Carol Miller

2014-01-01

When the federal agencies established policies in the late 1960s and early 1970s to allow the use of natural fires in wilderness, they launched a natural fire management experiment in a handful of wilderness areas. As a result, wildland fire has played more of its natural role in wilderness than anywhere else. Much of what we understand about fire ecology comes from...

Fire risk in California

Science.gov (United States)

Peterson, Seth Howard

Fire is an integral part of ecosystems in the western United States. Decades of fire suppression have led to (unnaturally) large accumulations of fuel in some forest communities, such as the lower elevation forests of the Sierra Nevada. Urban sprawl into fire prone chaparral vegetation in southern California has put human lives at risk and the decreased fire return intervals have put the vegetation community at risk of type conversion. This research examines the factors affecting fire risk in two of the dominant landscapes in the state of California, chaparral and inland coniferous forests. Live fuel moisture (LFM) is important for fire ignition, spread rate, and intensity in chaparral. LFM maps were generated for Los Angeles County by developing and then inverting robust cross-validated regression equations from time series field data and vegetation indices (VIs) and phenological metrics from MODIS data. Fire fuels, including understory fuels which are not visible to remote sensing instruments, were mapped in Yosemite National Park using the random forests decision tree algorithm and climatic, topographic, remotely sensed, and fire history variables. Combining the disparate data sources served to improve classification accuracies. The models were inverted to produce maps of fuel models and fuel amounts, and these showed that fire fuel amounts are highest in the low elevation forests that have been most affected by fire suppression impacting the natural fire regime. Wildland fires in chaparral commonly burn in late summer or fall when LFM is near its annual low, however, the Jesusita Fire burned in early May of 2009, when LFM was still relatively high. The HFire fire spread model was used to simulate the growth of the Jesusita Fire using LFM maps derived from imagery acquired at the time of the fire and imagery acquired in late August to determine how much different the fire would have been if it had occurred later in the year. Simulated fires were 1.5 times larger

Fire Behavior System for the Full Range of Fire Management Needs

Science.gov (United States)

Richard C. Rothermel; Patricia L. Andrews

1987-01-01

An "integrated fire behavior/fire danger rating system" should be "seamless" to avoid requiring choices among alternate, independent systems. Descriptions of fuel moisture, fuels, and fire behavior should be standardized, permitting information to flow easily through the spectrum of fire management needs. The level of resolution depends on the...

Fire Resistance Tests of Various Fire Protective Coatings

Directory of Open Access Journals (Sweden)

Mindaugas GRIGONIS

2011-03-01

Full Text Available Tests were carried out on more than 14 different samples of fire protective coatings in order to investigate a relation between the thickness of the intumescent fire protection coating and the time of exposure to heat. A number of coatings of different chemical composition enabled to determine the fire resistance behaviour patterns. During test the one-side and volumetric methods were employed in observance of the standard temperature-time curves. For one-side method, the coating was applied on one side and all edges of the specimen, whereas for volumetric test the specimens were completely covered with fire protective coating. It is shown that a layer of coating protects the specimen's surface from heat exposure for a certain period of time until full oxidation of the coating occurs. The efficiency of fire protective coatings also depends on thickness of the charred layer of the side exposed to heat.http://dx.doi.org/10.5755/j01.ms.17.1.257

FIRE CHARACTERISTICS FOR ADVANCED MODELLING OF FIRES

OpenAIRE

Otto Dvořák

2016-01-01

This paper summarizes the material and fire properties of solid flammable/combustible materials /substances /products, which are used as inputs for the computer numerical fire models. At the same time it gives the test standards for their determination.

Fire retardant formulations

DEFF Research Database (Denmark)

2017-01-01

The present invention relates to compositions where a substrate is liable to catch fire such as bituminous products, paints, carpets or the like. The invention relates to a composition comprising 40-95 weight % of a substrate to be rendered fire resistant such as bituminous material or paint......, carpets which substrate is mixed with 5-60 weight % of a fire retardant component. The invention relates to a fire retardant component comprising or being constituted of attapulgite, and a salt being a source of a blowing or expanding agent, where the attapulgite and the salt are electrostatically...... connected by mixing and subjecting the mixture of the two components to agitation. Also, the invention relates to compositions comprising 40-95 weight % of a substrate to be rendered fire resistant mixed with 5-60 weight % of a fire retardant according to claim 1 or 2, which fire retardant component...

Um estudo sobre gestão do conhecimento e inovação em uma empresa multinacional do setor de fast-food: o caso da Subway

OpenAIRE

Oliveira, Paulo Henrique de; Gonçalves, Carlos Alberto; de Paula, Edmar Aderson Mendes; Assis, Vivian Coelho

2013-01-01

Este artigo analisa as práticas de gestão do conhecimento e da inovação em uma franquia de uma importante empresa multinacional do setor de fast-food de Minas Gerais: a Subway. Como estratégia de pesquisa, utilizou-se um estudo de caso descritivo e os dados foram coletados por meio de uma entrevista em profundidade, realizada com o proprietário de quatro lojas dessa franquia, situadas em regiões estratégicas da cidade de Belo Horizonte. Os resultados demonstraram que os processos de criação, ...

Vegetation responses to season of fire in an aseasonal, fire-prone fynbos shrubland

Directory of Open Access Journals (Sweden)

Tineke Kraaij

2017-08-01

Full Text Available Season of fire has marked effects on floristic composition in fire-prone Mediterranean-climate shrublands. In these winter-rainfall systems, summer-autumn fires lead to optimal recruitment of overstorey proteoid shrubs (non-sprouting, slow-maturing, serotinous Proteaceae which are important to the conservation of floral diversity. We explored whether fire season has similar effects on early establishment of five proteoid species in the eastern coastal part of the Cape Floral Kingdom (South Africa where rainfall occurs year-round and where weather conducive to fire and the actual incidence of fire are largely aseasonal. We surveyed recruitment success (ratio of post-fire recruits to pre-fire parents of proteoids after fires in different seasons. We also planted proteoid seeds into exclosures, designed to prevent predation by small mammals and birds, in cleared (intended to simulate fire fynbos shrublands at different sites in each of four seasons and monitored their germination and survival to one year post-planting (hereafter termed ‘recruitment’. Factors (in decreasing order of importance affecting recruitment success in the post-fire surveys were species, pre-fire parent density, post-fire age of the vegetation at the time of assessment, and fire season, whereas rainfall (for six months post-fire and fire return interval (>7 years had little effect. In the seed-planting experiment, germination occurred during the cooler months and mostly within two months of planting, except for summer-plantings, which took 2–3 months longer to germinate. Although recruitment success differed significantly among planting seasons, sites and species, significant interactions occurred among the experimental factors. In both the post-fire surveys and seed planting experiment, recruitment success in relation to fire- or planting season varied greatly within and among species and sites. Results of these two datasets were furthermore inconsistent, suggesting

Vegetation responses to season of fire in an aseasonal, fire-prone fynbos shrubland.

Science.gov (United States)

Kraaij, Tineke; Cowling, Richard M; van Wilgen, Brian W; Rikhotso, Diba R; Difford, Mark

2017-01-01

Season of fire has marked effects on floristic composition in fire-prone Mediterranean-climate shrublands. In these winter-rainfall systems, summer-autumn fires lead to optimal recruitment of overstorey proteoid shrubs (non-sprouting, slow-maturing, serotinous Proteaceae) which are important to the conservation of floral diversity. We explored whether fire season has similar effects on early establishment of five proteoid species in the eastern coastal part of the Cape Floral Kingdom (South Africa) where rainfall occurs year-round and where weather conducive to fire and the actual incidence of fire are largely aseasonal. We surveyed recruitment success (ratio of post-fire recruits to pre-fire parents) of proteoids after fires in different seasons. We also planted proteoid seeds into exclosures, designed to prevent predation by small mammals and birds, in cleared (intended to simulate fire) fynbos shrublands at different sites in each of four seasons and monitored their germination and survival to one year post-planting (hereafter termed 'recruitment'). Factors (in decreasing order of importance) affecting recruitment success in the post-fire surveys were species, pre-fire parent density, post-fire age of the vegetation at the time of assessment, and fire season, whereas rainfall (for six months post-fire) and fire return interval (>7 years) had little effect. In the seed-planting experiment, germination occurred during the cooler months and mostly within two months of planting, except for summer-plantings, which took 2-3 months longer to germinate. Although recruitment success differed significantly among planting seasons, sites and species, significant interactions occurred among the experimental factors. In both the post-fire surveys and seed planting experiment, recruitment success in relation to fire- or planting season varied greatly within and among species and sites. Results of these two datasets were furthermore inconsistent, suggesting that proteoid

A hierarchical fire frequency model to simulate temporal patterns of fire regimes in LANDIS

Science.gov (United States)

Jian Yang; Hong S. He; Eric J. Gustafson

2004-01-01

Fire disturbance has important ecological effects in many forest landscapes. Existing statistically based approaches can be used to examine the effects of a fire regime on forest landscape dynamics. Most examples of statistically based fire models divide a fire occurrence into two stages--fire ignition and fire initiation. However, the exponential and Weibull fire-...

FIRE CHARACTERISTICS FOR ADVANCED MODELLING OF FIRES

Directory of Open Access Journals (Sweden)

Otto Dvořák

2016-07-01

Full Text Available This paper summarizes the material and fire properties of solid flammable/combustible materials /substances /products, which are used as inputs for the computer numerical fire models. At the same time it gives the test standards for their determination.

Stochastic representation of fire behavior in a wildland fire protection planning model for California.

Science.gov (United States)

J. Keith Gilless; Jeremy S. Fried

1998-01-01

A fire behavior module was developed for the California Fire Economics Simulator version 2 (CFES2), a stochastic simulation model of initial attack on wildland fire used by the California Department of Forestry and Fire Protection. Fire rate of spread (ROS) and fire dispatch level (FDL) for simulated fires "occurring" on the same day are determined by making...

Wildland fire in ecosystems: effects of fire on fauna

Science.gov (United States)

Jane Kapler Smith

2000-01-01

VOLUME 1: Fires affect animals mainly through effects on their habitat. Fires often cause short-term increases in wildlife foods that contribute to increases in populations of some animals. These increases are moderated by the animals' ability to thrive in the altered, often simplified, structure of the postfire environment. The extent of fire effects on animal...

Wildland fire in ecosystems: effects of fire on soils and water

Science.gov (United States)

Daniel G. Neary; Kevin C. Ryan; Leonard F. DeBano

2005-01-01

This state-of-knowledge review about the effects of fire on soils and water can assist land and fire managers with information on the physical, chemical, and biological effects of fire needed to successfully conduct ecosystem management, and effectively inform others about the role and impacts of wildland fire. Chapter topics include the soil resource, soil physical...

Fire risk analysis, fire simulation, fire spreading and impact of smoke and heat on instrumentation electronics - State-of-the-Art Report

International Nuclear Information System (INIS)

Roewekamp, M.; Bertrand, R.; Bonneval, F.; Hamblen, D.; Siu, N.; Aulamo, H.; Martila, J.; Sandberg, J.; Virolainen, R.

2000-01-01

Numerous fire PSAs (probabilistic safety assessments) have shown that fire can be a major contributor to nuclear power plant risk. However, there are considerable uncertainties in the results of these assessments, due to significant gaps in current abilities to perform realistic assessments. These gaps involve multiple aspects of fire PSA, including the estimation of the probability of important fire scenarios, the modeling of fire growth and suppression, the prediction of fire-induced damage to equipment (including the effects of smoke), and the treatment of plant and operator responses to the fire. In response to recommendations of /VIR 93/, CSNI/PWG5 established a Task Group to review the present status and maturity of current methods used in fire risk assessments for operating nuclear power plants. The Task Group issued a questionnaire in May 1997 to all nuclear power generating OECD countries. The prime focus of the questionnaire (see Appendix A) was on a number of important issues in fire PSA: Fire PSA methodology and applications; Fire simulation codes; Ignition and damageability data; Modeling of fire spread on cables or other equipment; Modeling of smoke production and spread; Impact of smoke and heat on instrumentation, electronics, or other electrical equipment; Impact of actual cable fires on safety systems. The questionnaire requested specific information on these topics (e.g., computer codes used in fire PSAs, the physical parameters used to model ignition). Responses to the questionnaire were provided by Finland, France, Germany, Hungary, Japan, Spain, Switzerland, United Kingdom, and the USA. This report summarizes the questionnaire responses and thereby: a) provides a perspective on the current fire PSA state of the art (SOAR) with respect to the issues listed above, and b) provides numerous references for more detailed information regarding these issues. The main responsibility for writing different chapters of this report was divided between some

Utilizing Multi-Sensor Fire Detections to Map Fires in the United States

Science.gov (United States)

Howard, S. M.; Picotte, J. J.; Coan, M. J.

2014-11-01

In 2006, the Monitoring Trends in Burn Severity (MTBS) project began a cooperative effort between the US Forest Service (USFS) and the U.S.Geological Survey (USGS) to map and assess burn severity all large fires that have occurred in the United States since 1984. Using Landsat imagery, MTBS is mandated to map wildfire and prescribed fire that meet specific size criteria: greater than 1000 acres in the west and 500 acres in the east, regardless of ownership. Relying mostly on federal and state fire occurrence records, over 15,300 individual fires have been mapped. While mapping recorded fires, an additional 2,700 "unknown" or undocumented fires were discovered and assessed. It has become apparent that there are perhaps thousands of undocumented fires in the US that are yet to be mapped. Fire occurrence records alone are inadequate if MTBS is to provide a comprehensive accounting of fire across the US. Additionally, the sheer number of fires to assess has overwhelmed current manual procedures. To address these problems, the National Aeronautics and Space Administration (NASA) Applied Sciences Program is helping to fund the efforts of the USGS and its MTBS partners (USFS, National Park Service) to develop, and implement a system to automatically identify fires using satellite data. In near real time, USGS will combine active fire satellite detections from MODIS, AVHRR and GOES satellites with Landsat acquisitions. Newly acquired Landsat imagery will be routinely scanned to identify freshly burned area pixels, derive an initial perimeter and tag the burned area with the satellite date and time of detection. Landsat imagery from the early archive will be scanned to identify undocumented fires. Additional automated fire assessment processes will be developed. The USGS will develop these processes using open source software packages in order to provide freely available tools to local land managers providing them with the capability to assess fires at the local level.

Crown Fire Potential

Data.gov (United States)

Earth Data Analysis Center, University of New Mexico — Crown fire potential was modeled using FlamMap, an interagency fire behavior mapping and analysis program that computes potential fire behavior characteristics. The...

Operating room fire prevention: creating an electrosurgical unit fire safety device.

Science.gov (United States)

Culp, William C; Kimbrough, Bradly A; Luna, Sarah; Maguddayao, Aris J

2014-08-01

To reduce the incidence of surgical fires. Operating room fires represent a potentially life-threatening hazard and are triggered by the electrosurgical unit (ESU) pencil. Carbon dioxide is a fire suppressant and is a routinely used medical gas. We hypothesize that a shroud of protective carbon dioxide covering the tip of the ESU pencil displaces oxygen, thereby preventing fire ignition. Using 3-dimensional modeling techniques, a polymer sleeve was created and attached to an ESU pencil. This sleeve was connected to a carbon dioxide source and directed the gas through multiple precisely angled ports, generating a cone of fire-suppressive carbon dioxide surrounding the active pencil tip. This device was evaluated in a flammability test chamber containing 21%, 50%, and 100% oxygen with sustained ESU activation. The sleeve was tested with and without carbon dioxide (control) until a fuel was ignited or 30 seconds elapsed. Time to ignition was measured by high-speed videography. Fires were ignited with each control trial (15/15 trials). The control group median ± SD ignition time in 21% oxygen was 3.0 ± 2.4 seconds, in 50% oxygen was 0.1 ± 1.8 seconds, and in 100% oxygen was 0.03 ± 0.1 seconds. No fire was observed when the fire safety device was used in all concentrations of oxygen (0/15 trials; P fire ignition was 76% to 100%. A sleeve creating a cone of protective carbon dioxide gas enshrouding the sparks from an ESU pencil effectively prevents fire in a high-flammability model. Clinical application of this device may reduce the incidence of operating room fires.

Active Fire Mapping Program

Science.gov (United States)

Active Fire Mapping Program Current Large Incidents (Home) New Large Incidents Fire Detection Maps MODIS Satellite Imagery VIIRS Satellite Imagery Fire Detection GIS Data Fire Data in Google Earth ...

Development of the fire PSA methodology and the fire analysis computer code system

International Nuclear Information System (INIS)

Katsunori, Ogura; Tomomichi, Ito; Tsuyoshi, Uchida; Yusuke, Kasagawa

2009-01-01

Fire PSA methodology has been developed and was applied to NPPs in Japan for power operation and LPSD states. CDFs of preliminary fire PSA for power operation were the higher than that of internal events. Fire propagation analysis code system (CFAST/FDS Network) was being developed and verified thru OECD-PRISME Project. Extension of the scope for LPSD state is planned to figure out the risk level. In order to figure out the fire risk level precisely, the enhancement of the methodology is planned. Verification and validation of phenomenological fire propagation analysis code (CFAST/FDS Network) in the context of Fire PSA. Enhancement of the methodology such as an application of 'Electric Circuit Analysis' in NUREG/CR-6850 and related tests in order to quantify the hot-short effect precisely. Development of seismic-induced fire PSA method being integration of existing seismic PSA and fire PSA methods is ongoing. Fire PSA will be applied to review the validity of fire prevention and mitigation measures

Loft fire protection

International Nuclear Information System (INIS)

White, E.R.; Jensen, J.D.

1980-01-01

Quantified criteria that was developed and applied to provide in-depth fire protection for the Loss of Fluid Test (LOFT) Facility are presented. The presentation describes the evolution process that elevated the facility's fire protection from minimal to that required for a highly protected risk or improved risk. Explored are some infrequently used fire protection measures that are poorly understood outside the fire protection profession

How fire history, fire suppression practices and climate change affect wildfire regimes in Mediterranean landscapes.

Directory of Open Access Journals (Sweden)

Lluís Brotons

Full Text Available Available data show that future changes in global change drivers may lead to an increasing impact of fires on terrestrial ecosystems worldwide. Yet, fire regime changes in highly humanised fire-prone regions are difficult to predict because fire effects may be heavily mediated by human activities We investigated the role of fire suppression strategies in synergy with climate change on the resulting fire regimes in Catalonia (north-eastern Spain. We used a spatially-explicit fire-succession model at the landscape level to test whether the use of different firefighting opportunities related to observed reductions in fire spread rates and effective fire sizes, and hence changes in the fire regime. We calibrated this model with data from a period with weak firefighting and later assess the potential for suppression strategies to modify fire regimes expected under different levels of climate change. When comparing simulations with observed fire statistics from an eleven-year period with firefighting strategies in place, our results showed that, at least in two of the three sub-regions analysed, the observed fire regime could not be reproduced unless taking into account the effects of fire suppression. Fire regime descriptors were highly dependent on climate change scenarios, with a general trend, under baseline scenarios without fire suppression, to large-scale increases in area burnt. Fire suppression strategies had a strong capacity to compensate for climate change effects. However, strong active fire suppression was necessary to accomplish such compensation, while more opportunistic fire suppression strategies derived from recent fire history only had a variable, but generally weak, potential for compensation of enhanced fire impacts under climate change. The concept of fire regime in the Mediterranean is probably better interpreted as a highly dynamic process in which the main determinants of fire are rapidly modified by changes in landscape

How fire history, fire suppression practices and climate change affect wildfire regimes in Mediterranean landscapes.

Science.gov (United States)

Brotons, Lluís; Aquilué, Núria; de Cáceres, Miquel; Fortin, Marie-Josée; Fall, Andrew

2013-01-01

Available data show that future changes in global change drivers may lead to an increasing impact of fires on terrestrial ecosystems worldwide. Yet, fire regime changes in highly humanised fire-prone regions are difficult to predict because fire effects may be heavily mediated by human activities We investigated the role of fire suppression strategies in synergy with climate change on the resulting fire regimes in Catalonia (north-eastern Spain). We used a spatially-explicit fire-succession model at the landscape level to test whether the use of different firefighting opportunities related to observed reductions in fire spread rates and effective fire sizes, and hence changes in the fire regime. We calibrated this model with data from a period with weak firefighting and later assess the potential for suppression strategies to modify fire regimes expected under different levels of climate change. When comparing simulations with observed fire statistics from an eleven-year period with firefighting strategies in place, our results showed that, at least in two of the three sub-regions analysed, the observed fire regime could not be reproduced unless taking into account the effects of fire suppression. Fire regime descriptors were highly dependent on climate change scenarios, with a general trend, under baseline scenarios without fire suppression, to large-scale increases in area burnt. Fire suppression strategies had a strong capacity to compensate for climate change effects. However, strong active fire suppression was necessary to accomplish such compensation, while more opportunistic fire suppression strategies derived from recent fire history only had a variable, but generally weak, potential for compensation of enhanced fire impacts under climate change. The concept of fire regime in the Mediterranean is probably better interpreted as a highly dynamic process in which the main determinants of fire are rapidly modified by changes in landscape, climate and

How Fire History, Fire Suppression Practices and Climate Change Affect Wildfire Regimes in Mediterranean Landscapes

Science.gov (United States)

Brotons, Lluís; Aquilué, Núria; de Cáceres, Miquel; Fortin, Marie-Josée; Fall, Andrew

2013-01-01

Available data show that future changes in global change drivers may lead to an increasing impact of fires on terrestrial ecosystems worldwide. Yet, fire regime changes in highly humanised fire-prone regions are difficult to predict because fire effects may be heavily mediated by human activities We investigated the role of fire suppression strategies in synergy with climate change on the resulting fire regimes in Catalonia (north-eastern Spain). We used a spatially-explicit fire-succession model at the landscape level to test whether the use of different firefighting opportunities related to observed reductions in fire spread rates and effective fire sizes, and hence changes in the fire regime. We calibrated this model with data from a period with weak firefighting and later assess the potential for suppression strategies to modify fire regimes expected under different levels of climate change. When comparing simulations with observed fire statistics from an eleven-year period with firefighting strategies in place, our results showed that, at least in two of the three sub-regions analysed, the observed fire regime could not be reproduced unless taking into account the effects of fire suppression. Fire regime descriptors were highly dependent on climate change scenarios, with a general trend, under baseline scenarios without fire suppression, to large-scale increases in area burnt. Fire suppression strategies had a strong capacity to compensate for climate change effects. However, strong active fire suppression was necessary to accomplish such compensation, while more opportunistic fire suppression strategies derived from recent fire history only had a variable, but generally weak, potential for compensation of enhanced fire impacts under climate change. The concept of fire regime in the Mediterranean is probably better interpreted as a highly dynamic process in which the main determinants of fire are rapidly modified by changes in landscape, climate and

The OECD FIRE database

International Nuclear Information System (INIS)

Angner, A.; Berg, H.P.; Roewekamp, M.; Werner, W.; Gauvain, J.

2007-01-01

Realistic modelling of fire scenarios is still difficult due to the scarcity of reliable data needed for deterministic and probabilistic fire safety analysis. Therefore, it has been recognized as highly important to establish a fire event database on an international level. In consequence, several member countries of the Nuclear Energy Agency of the OECD have decided in 2000 to establish the International Fire Data Exchange Project (OECD FIRE) to encourage multilateral co-operation in the collection and analysis of data related to fire events at nuclear power plants. This paper presents the OECD FIRE project objectives, work scope and current status of the OECD FIRE database after 3 years of operation as well as first preliminary statistical insights gained from the collected data. (orig.)

Biomass co-firing

DEFF Research Database (Denmark)

Yin, Chungen

2013-01-01

Co-firing biomass with fossil fuels in existing power plants is an attractive option for significantly increasing renewable energy resource utilization and reducing CO2 emissions. This chapter mainly discusses three direct co-firing technologies: pulverized-fuel (PF) boilers, fluidized-bed combus......Co-firing biomass with fossil fuels in existing power plants is an attractive option for significantly increasing renewable energy resource utilization and reducing CO2 emissions. This chapter mainly discusses three direct co-firing technologies: pulverized-fuel (PF) boilers, fluidized......-bed combustion (FBC) systems, and grate-firing systems, which are employed in about 50%, 40% and 10% of all the co-firing plants, respectively. Their basic principles, process technologies, advantages, and limitations are presented, followed by a brief comparison of these technologies when applied to biomass co...

Supporting FIRE-suppression strategies combining fire spread MODelling and SATellite data in an operational context in Portugal: the FIRE-MODSAT project

Science.gov (United States)

Sá, Ana C. L.; Benali, Akli; Pinto, Renata M. S.; Pereira, José M. C.; Trigo, Ricardo M.; DaCamara, Carlos C.

2014-05-01

Large wildfires are infrequent but account for the most severe environmental, ecological and socio-economic impacts. In recent years Portugal has suffered the impact of major heat waves that fuelled records of burnt area exceeding 400.000ha and 300.000ha in 2003 and 2005, respectively. According to the latest IPCC reports, the frequency and amplitude of summer heat waves over Iberia will very likely increase in the future. Therefore, most climate change studies point to an increase in the number and extent of wildfires. Thus, an increase in both wildfire impacts and fire suppression difficulties is expected. The spread of large wildfires results from a complex interaction between topography, meteorology and fuel properties. Wildfire spread models (e.g. FARSITE) are commonly used to simulate fire growth and behaviour and are an essential tool to understand their main drivers. Additionally, satellite active-fire data have been used to monitor the occurrence, extent, and spread of wildfires. Both satellite data and fire spread models provide different types of information about the spatial and temporal distribution of large wildfires and can potentially be used to support strategic decisions regarding fire suppression resource allocation. However, they have not been combined in a manner that fully exploits their potential and minimizes their limitations. A knowledge gap still exists in understanding how to minimize the impacts of large wildfires, leading to the following research question: What can we learn from past large wildfires in order to mitigate future fire impacts? FIRE-MODSAT is a one-year funded project by the Portuguese Foundation for the Science and Technology (FCT) that is founded on this research question, with the main goal of improving our understanding on the interactions between fire spread and its environmental drivers, to support fire management decisions in an operational context and generate valuable information to improve the efficiency of the

30 CFR 75.1103-6 - Automatic fire sensors; actuation of fire suppression systems.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Automatic fire sensors; actuation of fire... Protection § 75.1103-6 Automatic fire sensors; actuation of fire suppression systems. Point-type heat sensors or automatic fire sensor and warning device systems may be used to actuate deluge-type water systems...

Fire protection in ventilation systems and in case of fire operating ventilation systems

International Nuclear Information System (INIS)

Zitzelsberger, J.

1983-01-01

The fire risks in ventilation systems are discussed. It follows a survey of regulations on fire prevention and fire protection in ventilation systems and smoke and heat exhaust systems applicable to nuclear installations in the Federal Republic of Germany. Fire protection concepts for normal systems and for systems operating also in case of fire will be given. Several structural elements for fire protection in those systems will be illustrated with regard to recent research findings

Quantitative comparison of fire danger index performance using fire activity

CSIR Research Space (South Africa)

Steenkamp, KC

2012-07-01

Full Text Available parameters such as flame length or rate of spread can be physically measured or modeled. Fire danger indices are not designed to describe the characteristics of a fire but rather the potential of a fire taking place in an area of interest [5]. Several...

The Pictorial Fire Stroop: A Measure of Processing Bias for Fire-Related Stimuli

Science.gov (United States)

Gallagher-Duffy, Joanne; MacKay, Sherri; Duffy, Jim; Sullivan-Thomas, Meara; Peterson-Badali, Michele

2009-01-01

Fire interest is a risk factor for firesetting. This study tested whether a fire-specific emotional Stroop task can effectively measure an information-processing bias for fire-related stimuli. Clinic-referred and nonreferred adolescents (aged 13-16 years) completed a pictorial "Fire Stroop," as well as a self-report fire interest questionnaire and…

Applications of Living Fire PRA models to Fire Protection Significance Determination Process in Taiwan

International Nuclear Information System (INIS)

De-Cheng, Chen; Chung-Kung, Lo; Tsu-Jen, Lin; Ching-Hui, Wu; Lin, James C.

2004-01-01

The living fire probabilistic risk assessment (PRA) models for all three operating nuclear power plants (NPPs) in Taiwan had been established in December 2000. In that study, a scenario-based PRA approach was adopted to systematically evaluate the fire and smoke hazards and associated risks. Using these fire PRA models developed, a risk-informed application project had also been completed in December 2002 for the evaluation of cable-tray fire-barrier wrapping exemption. This paper presents a new application of the fire PRA models to fire protection issues using the fire protection significance determination process (FP SDP). The fire protection issues studied may involve the selection of appropriate compensatory measures during the period when an automatic fire detection or suppression system in a safety-related fire zone becomes inoperable. The compensatory measure can either be a 24-hour fire watch or an hourly fire patrol. The living fire PRA models were used to estimate the increase in risk associated with the fire protection issue in terms of changes in core damage frequency (CDF) and large early release frequency (LERF). In compliance with SDP at-power and the acceptance guidelines specified in RG 1.174, the fire protection issues in question can be grouped into four categories; red, yellow, white and green, in accordance with the guidelines developed for FD SDP. A 24-hour fire watch is suggested only required for the yellow condition, while an hourly fire patrol may be adopted for the white condition. More limiting requirement is suggested for the red condition, but no special consideration is needed for the green condition. For the calculation of risk measures, risk impacts from any additional fire scenarios that may have been introduced, as well as more severe initiating events and fire damages that may accompany the fire protection issue should be considered carefully. Examples are presented in this paper to illustrate the evaluation process. (authors)

Fire protection: no fire without smoke. CCTV breakthrough in fire detection

International Nuclear Information System (INIS)

Anon.

1997-01-01

A new CCTV-based fire detection system uses advanced software to detect and locate smoke and vapour from a fire before it becomes visible to the human eye, but is intelligent enough to avoid false alarms due to steam, moving machinery or operating staff in the monitored area. The starting point for the development effort was video motion detection software as used in the security industry. (author)

Advanced Fire Information System - A real time fire information system for Africa

Science.gov (United States)

Frost, P. E.; Roy, D. P.

2012-12-01

The Council for Scientific and Industrial Research (CSIR) lead by the Meraka Institute and supported by the South African National Space Agency (SANSA) developed the Advanced Fire Information System (AFIS) to provide near real time fire information to a variety of operational and science fire users including disaster managers, fire fighters, farmers and forest managers located across Southern and Eastern Africa. The AFIS combines satellite data with ground based observations and statistics and distributes the information via mobile phone technology. The system was launched in 2004, and Eskom (South Africa' and Africa's largest power utility) quickly became the biggest user and today more than 300 Eskom line managers and support staff receive cell phone and email fire alert messages whenever a wildfire is within 2km of any of the 28 000km of Eskom electricity transmission lines. The AFIS uses Earth observation satellites from NASA and Europe to detect possible actively burning fires and their fire radiative power (FRP). The polar orbiting MODIS Terra and Aqua satellites provide data at around 10am, 15pm, 22am and 3am daily, while the European Geostationary MSG satellite provides 15 minute updates at lower spatial resolution. The AFIS processing system ingests the raw satellite data and within minutes of the satellite overpass generates fire location and FRP based fire intensity information. The AFIS and new functionality are presented including an incident report and permiting system that can be used to differentiate between prescribed burns and uncontrolled wild fires, and the provision of other information including 5-day fire danger forecasts, vegetation curing information and historical burned area maps. A new AFIS mobile application for IOS and Android devices as well as a fire reporting tool are showcased that enable both the dissemination and alerting of fire information and enable user upload of geo tagged photographs and on the fly creation of fire reports

Fire safety

International Nuclear Information System (INIS)

Keski-Rahkonen, O.; Bjoerkman, J.; Hostikka, S.; Mangs, J.; Huhtanen, R.; Palmen, H.; Salminen, A.; Turtola, A.

1998-01-01

According to experience and probabilistic risk assessments, fires present a significant hazard in a nuclear power plant. Fires may be initial events for accidents or affect safety systems planned to prevent accidents and to mitigate their consequences. The project consists of theoretical work, experiments and simulations aiming to increase the fire safety at nuclear power plants. The project has four target areas: (1) to produce validated models for numerical simulation programmes, (2) to produce new information on the behavior of equipment in case of fire, (3) to study applicability of new active fire protecting systems in nuclear power plants, and (4) to obtain quantitative knowledge of ignitions induced by important electric devices in nuclear power plants. These topics have been solved mainly experimentally, but modelling at different level is used to interpret experimental data, and to allow easy generalisation and engineering use of the obtained data. Numerical fire simulation has concentrated in comparison of CFD modelling of room fires, and fire spreading on cables on experimental data. So far the success has been good to fair. A simple analytical and numerical model has been developed for fire effluents spreading beyond the room of origin in mechanically strongly ventilated compartments. For behaviour of equipment in fire several full scale and scaled down calorimetric experiments were carried out on electronic cabinets, as well as on horizontal and vertical cable trays. These were carried out to supply material for CFD numerical simulation code validation. Several analytical models were developed and validated against obtained experimental results to allow quick calculations for PSA estimates as well as inter- and extrapolations to slightly different objects. Response times of different commercial fire detectors were determined for different types of smoke, especially emanating from smoldering and flaming cables to facilitate selection of proper detector

Nuclear power plant fire protection: fire detection (subsystems study Task 2)

International Nuclear Information System (INIS)

Berry, D.L.

1977-12-01

This report examines the adequacy of fire detection in the context of nuclear power plant safety. Topics considered are: (1) establishing area detection requirements, (2) selecting specific detector types, (3) locating and spacing detectors, and (4) performing installation tests and maintenance. Based on a thorough review of fire detection codes and standards and fire detection literature, the report concludes that current design and regulatory guidelines alone are insufficient to ensure satisfactory fire detection system performance. To assure adequate fire detection, this report recommends the use of in-place testing of detectors under conditions expected to occur normally in areas being protected

Fire Models and Design Fires

DEFF Research Database (Denmark)

Poulsen, Annemarie

The aim of this project is to perform an experimental study on the influence of the thermal feedback on the burning behavior of well ventilated pre-flashover fires. For the purpose an experimental method has been developed. Here the same identical objects are tested under free burn conditions...... carried out by Carleton University and NRC-IRC performed on seven different types of fire loads representing commercial premises, comprise the tests used for the study. The results show that for some of the room test the heat release rate increased due to thermal feedback compared to free burn for a pre......-flashover fire. Two phenomena were observed, that relate well to theory was found. In an incipient phase the heat release rate rose with the temperature of the smoke layer/enclosure boundaries. This increase was also found to depend on the flammability properties of the burning object. The results also...

Fire danger and fire behavior modeling systems in Australia, Europe, and North America

Science.gov (United States)

Francis M. Fujioka; A. Malcolm Gill; Domingos X. Viegas; B. Mike Wotton

2009-01-01

Wildland fire occurrence and behavior are complex phenomena involving essentially fuel (vegetation), topography, and weather. Fire managers around the world use a variety of systems to track and predict fire danger and fire behavior, at spatial scales that span from local to global extents, and temporal scales ranging from minutes to seasons. The fire management...

Fire Ant Bites

Science.gov (United States)

... Favorite Name: Category: Share: Yes No, Keep Private Fire Ant Bites Share | Fire ants are aggressive, venomous insects that have pinching ... across the United States, even into Puerto Rico. Fire ant stings usually occur on the feet or ...

Fire protection for clean rooms

International Nuclear Information System (INIS)

Kirson, D.

1990-01-01

The fire protection engineer often must decide what size fire can be tolerated before automatic fire suppression systems actuate. Is it a wastepaper basket fire, a bushel basket fire...? In the case of state-of-the-art clean rooms, the answer clearly is not even an incipient fire. Minor fires in clean rooms can cause major losses. This paper discusses what a clean room is and gives a brief overview of the unique fire protection challenges encountered. The two major causes of fire related to clean rooms in the semiconductor industry are flammable/pyrophoric gas fires in plastic ducts and polypropylene wet bench fires. This paper concentrates on plastic ductwork in clean rooms, sprinkler protection in ductwork, and protection for wet benches

Ecological fire use for ecological fire management: Managing large wildfires by design

Science.gov (United States)

Timothy Ingalsbee

2015-01-01

Past fire exclusion policies and fire suppression actions have led to a historic "fire deficit" on public wildlands. These sociocultural actions have led to unprecedented environmental changes that have created conditions conducive to more frequent large-scale wildfires. Politicians, the newsmedia, and agency officials portray large wildland fires as...

Fire Safety (For Parents)

Science.gov (United States)

... Staying Safe Videos for Educators Search English Español Fire Safety KidsHealth / For Parents / Fire Safety What's in ... event of a fire emergency in your home. Fire Prevention Of course, the best way to practice ...

Seasonality of fire weather strongly influences fire regimes in South Florida savanna-grassland landscapes.

Directory of Open Access Journals (Sweden)

William J Platt

Full Text Available Fire seasonality, an important characteristic of fire regimes, commonly is delineated using seasons based on single weather variables (rainfall or temperature. We used nonparametric cluster analyses of a 17-year (1993-2009 data set of weather variables that influence likelihoods and spread of fires (relative humidity, air temperature, solar radiation, wind speed, soil moisture to explore seasonality of fire in pine savanna-grassland landscapes at the Avon Park Air Force Range in southern Florida. A four-variable, three-season model explained more variation within fire weather variables than models with more seasons. The three-season model also delineated intra-annual timing of fire more accurately than a conventional rainfall-based two-season model. Two seasons coincided roughly with dry and wet seasons based on rainfall. The third season, which we labeled the fire season, occurred between dry and wet seasons and was characterized by fire-promoting conditions present annually: drought, intense solar radiation, low humidity, and warm air temperatures. Fine fuels consisting of variable combinations of pyrogenic pine needles, abundant C4 grasses, and flammable shrubs, coupled with low soil moisture, and lightning ignitions early in the fire season facilitate natural landscape-scale wildfires that burn uplands and across wetlands. We related our three season model to fires with different ignition sources (lightning, military missions, and prescribed fires over a 13-year period with fire records (1997-2009. Largest wildfires originate from lightning and military ignitions that occur within the early fire season substantially prior to the peak of lightning strikes in the wet season. Prescribed ignitions, in contrast, largely occur outside the fire season. Our delineation of a pronounced fire season provides insight into the extent to which different human-derived fire regimes mimic lightning fire regimes. Delineation of a fire season associated with

Seasonality of Fire Weather Strongly Influences Fire Regimes in South Florida Savanna-Grassland Landscapes

Science.gov (United States)

Platt, William J.; Orzell, Steve L.; Slocum, Matthew G.

2015-01-01

Fire seasonality, an important characteristic of fire regimes, commonly is delineated using seasons based on single weather variables (rainfall or temperature). We used nonparametric cluster analyses of a 17-year (1993–2009) data set of weather variables that influence likelihoods and spread of fires (relative humidity, air temperature, solar radiation, wind speed, soil moisture) to explore seasonality of fire in pine savanna-grassland landscapes at the Avon Park Air Force Range in southern Florida. A four-variable, three-season model explained more variation within fire weather variables than models with more seasons. The three-season model also delineated intra-annual timing of fire more accurately than a conventional rainfall-based two-season model. Two seasons coincided roughly with dry and wet seasons based on rainfall. The third season, which we labeled the fire season, occurred between dry and wet seasons and was characterized by fire-promoting conditions present annually: drought, intense solar radiation, low humidity, and warm air temperatures. Fine fuels consisting of variable combinations of pyrogenic pine needles, abundant C4 grasses, and flammable shrubs, coupled with low soil moisture, and lightning ignitions early in the fire season facilitate natural landscape-scale wildfires that burn uplands and across wetlands. We related our three season model to fires with different ignition sources (lightning, military missions, and prescribed fires) over a 13-year period with fire records (1997–2009). Largest wildfires originate from lightning and military ignitions that occur within the early fire season substantially prior to the peak of lightning strikes in the wet season. Prescribed ignitions, in contrast, largely occur outside the fire season. Our delineation of a pronounced fire season provides insight into the extent to which different human-derived fire regimes mimic lightning fire regimes. Delineation of a fire season associated with timing of

National and international standards and recommendations on fire protection and fire safety assessment

International Nuclear Information System (INIS)

Berg, H.P.

2007-01-01

Experience feedback from events in nuclear facilities worldwide has shown that fire can represent a safety significant hazard. Thus, the primary objectives of fire protection programmes are to minimize both the probability of occurrence and the consequences of a fire. The regulator body expects that the licensees justify their arrangements for identifying how fires can occur and spread, assess the vulnerability of plant equipment and structures, determine how the safe operation of a plant is affected, and introduce measures to prevent a fire hazard from developing and propagating as well as to mitigate its effects in case the fire cannot be prevented. For that purpose usually a comprehensive regulatory framework for fire protection has been elaborated, based on national industrial regulations, nuclear specific regulations as well as international recommendations or requirements. Examples of such national and international standards and recommendations on fire protection and fire safety assessment as well as ongoing activities in this field are described. (orig.)

Fire protection program fiscal year 1995 site support program plan, Hanford Fire Department

International Nuclear Information System (INIS)

Good, D.E.

1994-09-01

The mission of the Hanford Fire Department (HFD) is to support the safe and timely cleanup of the Hanford site by providing fire suppression, fire prevention, emergency rescue, emergency medical service, and hazardous materials response; and to be capable of dealing with and terminating emergency situations which could threaten the operations, employees, or interest of the US Department of Energy operated Hanford Site. This includes response to surrounding fire departments/districts under a mutual aid agreement and contractual fire fighting, hazardous materials, and ambulance support to Washington Public Power Supply System (Supply System). The fire department also provides site fire marshal overview authority, fire system testing and maintenance, self-contained breathing apparatus maintenance, building tours and inspections, ignitable and reactive waste site inspections, prefire planning, and employee fire prevention education. This report describes the specific responsibilities and programs that the HFD must support and the estimated cost of this support for FY1995

Fire, safety and ventilation

Energy Technology Data Exchange (ETDEWEB)

Hindle, D.

1999-02-01

Correct ventilation in tunnel environments is vital for the comfort and safety of the people passing through. This article gives details of products from several manufacturers of safety rescue and fire fighting equipment, fire and fume detection equipment, special fire resistant materials, fire resistant hydraulic oils and fire dampers, and ventilation systems. Company addresses and fax numbers are supplied. 4 refs., 5 tabs., 10 photos.

Remote sensing techniques to assess active fire characteristics and post-fire effects

Science.gov (United States)

Leigh B. Lentile; Zachary A. Holden; Alistair M. S. Smith; Michael J. Falkowski; Andrew T. Hudak; Penelope Morgan; Sarah A. Lewis; Paul E. Gessler; Nate C. Benson

2006-01-01

Space and airborne sensors have been used to map area burned, assess characteristics of active fires, and characterize post-fire ecological effects. Confusion about fire intensity, fire severity, burn severity, and related terms can result in the potential misuse of the inferred information by land managers and remote sensing practitioners who require unambiguous...

Delay-induced diversity of firing behavior and ordered chaotic firing in adaptive neuronal networks

International Nuclear Information System (INIS)

Gong Yubing; Wang Li; Xu Bo

2012-01-01

In this paper, we study the effect of time delay on the firing behavior and temporal coherence and synchronization in Newman–Watts thermosensitive neuron networks with adaptive coupling. At beginning, the firing exhibit disordered spiking in absence of time delay. As time delay is increased, the neurons exhibit diversity of firing behaviors including bursting with multiple spikes in a burst, spiking, bursting with four, three and two spikes, firing death, and bursting with increasing amplitude. The spiking is the most ordered, exhibiting coherence resonance (CR)-like behavior, and the firing synchronization becomes enhanced with the increase of time delay. As growth rate of coupling strength or network randomness increases, CR-like behavior shifts to smaller time delay and the synchronization of firing increases. These results show that time delay can induce diversity of firing behaviors in adaptive neuronal networks, and can order the chaotic firing by enhancing and optimizing the temporal coherence and enhancing the synchronization of firing. However, the phenomenon of firing death shows that time delay may inhibit the firing of adaptive neuronal networks. These findings provide new insight into the role of time delay in the firing activity of adaptive neuronal networks, and can help to better understand the complex firing phenomena in neural networks.

Geological Hazards analysis in Urban Tunneling by EPB Machine (Case study: Tehran subway line 7 tunnel

Directory of Open Access Journals (Sweden)

Hassan Bakhshandeh Amnieh

2016-06-01

Full Text Available Technological progress in tunneling has led to modern and efficient tunneling methods in vast underground spaces even under inappropriate geological conditions. Identification and access to appropriate and sufficient geological hazard data are key elements to successful construction of underground structures. Choice of the method, excavation machine, and prediction of suitable solutions to overcome undesirable conditions depend on geological studies and hazard analysis. Identifying and investigating the ground hazards in excavating urban tunnels by an EPB machine could augment the strategy for improving soil conditions during excavation operations. In this paper, challenges such as geological hazards, abrasion of the machine cutting tools, clogging around these tools and inside the chamber, diverse work front, severe water level fluctuations, existence of water, and fine-grained particles in the route were recognized in a study of Tehran subway line 7, for which solutions such as low speed boring, regular cutter head checks, application of soil improving agents, and appropriate grouting were presented and discussed. Due to the presence of fine particles in the route, foam employment was suggested as the optimum strategy where no filler is needed.

Tunnel boring machine collision with an ancient boulder beach during the excavation of the Barcelona city subway L10 line: a case of adverse geology and resulting engineering solutions

OpenAIRE

Filbà, Marta; Salvany Duran, Josep Maria; Jubany, Jordi; Carrasco, Laura

2016-01-01

The existence of a layer of hard boulders up to 1 m in size within the soft sediments of the Holocene Llobregat delta in the SW of Barcelona city caused the damage and stoppage of the EPB-type tunnel boring machine that excavated the subway L10 line. This layer constitutes a detrital deposit of exceptionally large grain size developed in the base of the delta. It originated as an alluvial fan in the northern margin of the delta during the last fall of the Mediterranean Sea level, at the end o...

Fires in Chile

Science.gov (United States)

2002-01-01

On February 5, 2002, the dense smoke from numerous forest fires stretched out over the Pacific Ocean about 400 miles south of Santiago, Chile. This true-color Moderate-resolution Imaging Spectroradiometer (MODIS) image shows the fires, which are located near the city of Temuco. The fires are indicated with red dots (boxes in the high-resolution imagery). The fires were burning near several national parks and nature reserves in an area of the Chilean Andes where tourism is very popular. Southeast of the fires, the vegetation along the banks of the Rio Negro in Argentina stands out in dark green. Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC

The Effects of Vegetative Type, Edges, Fire History, Rainfall and Management in Fire-Maintained Habitat

Science.gov (United States)

Breininger, David R.; Foster, Tammy E.; Carter, Geoffrey M.; Duncan, Brean W.; Stolen, Eric D.; Lyon, James E.

2018-01-01

The combined effects of fire history, climate, and landscape features (e.g., edges) on habitat specialists need greater focus in fire ecology studies, which usually only emphasize characteristics of the most recent fire. Florida scrub-jays are an imperiled, territorial species that prefer medium (1.2-1.7 m) shrub heights, which are dynamic because of frequent fires. We measured short, medium, and tall habitat quality states annually within 10 ha grid cells (that represented potential territories) because fires and vegetative recovery cause annual variation in habitat quality. We used multistate models and model selection to test competing hypotheses about how transition probabilities vary between states as functions of environmental covariates. Covariates included vegetative type, edges (e.g., roads, forests), precipitation, openings (gaps between shrubs), mechanical cutting, and fire characteristics. Fire characteristics not only included an annual presence/absence of fire covariate, but also fire history covariates: time since the previous fire, the longest fire-free interval, and the number of repeated fires. Statistical models with support included many covariates for each transition probability, often including fire history, interactions and nonlinear relationships. Tall territories resulted from 28 years of fire suppression and habitat fragmentation that reduced the spread of fires across landscapes. Despite 35 years of habitat restoration and prescribed fires, half the territories remained tall suggesting a regime shift to a less desirable habitat condition. Edges reduced the effectiveness of fires in setting degraded scrub and flatwoods into earlier successional states making mechanical cutting an important tool to compliment frequent prescribed fires.

Fire Risk Scoping Study: Investigation of nuclear power plant fire risk, including previously unaddressed issues

International Nuclear Information System (INIS)

Lambright, J.A.; Nowlen, S.P.; Nicolette, V.F.; Bohn, M.P.

1989-01-01

An investigation of nuclear power plant fire risk issues raised as a result of the USNRC sponsored Fire Protection Research Program at Sandia National Laboratories has been performed. The specific objectives of this study were (1) to review and requantify fire risk scenarios from four fire probabilistic risk assessments (PRAs) in light of updated data bases made available as a result of USNRC sponsored Fire Protection Research Program and updated computer fire modeling capabilities, (2) to identify potentially significant fire risk issues that have not been previously addressed in a fire risk context and to quantify the potential impact of those identified fire risk issues where possible, and (3) to review current fire regulations and plant implementation practices for relevance to the identified unaddressed fire risk issues. In performance of the fire risk scenario requantifications several important insights were gained. It was found that utilization of a more extensive operational experience base resulted in both fire occurrence frequencies and fire duration times (i.e., time required for fire suppression) increasing significantly over those assumed in the original works. Additionally, some thermal damage threshold limits assumed in the original works were identified as being nonconservative based on more recent experimental data. Finally, application of the COMPBRN III fire growth model resulted in calculation of considerably longer fire damage times than those calculated in the original works using COMPBRN I. 14 refs., 2 figs., 16 tabs

Designing fire safe interiors.

Science.gov (United States)

Belles, D W

1992-01-01

Any product that causes a fire to grow large is deficient in fire safety performance. A large fire in any building represents a serious hazard. Multiple-death fires almost always are linked to fires that grow quickly to a large size. Interior finishes have large, continuous surfaces over which fire can spread. They are regulated to slow initial fire growth, and must be qualified for use on the basis of fire tests. To obtain meaningful results, specimens must be representative of actual installation. Variables--such as the substrate, the adhesive, and product thickness and density--can affect product performance. The tunnel test may not adequately evaluate some products, such as foam plastics or textile wall coverings, thermoplastic materials, or materials of minimal mass. Where questions exist, products should be evaluated on a full-scale basis. Curtains and draperies are examples of products that ignite easily and spread flames readily. The present method for testing curtains and draperies evaluates one fabric at a time. Although a fabric tested alone may perform well, fabrics that meet test standards individually sometimes perform poorly when tested in combination. Contents and furnishings constitute the major fuels in many fires. Contents may involve paper products and other lightweight materials that are easily ignited and capable of fast fire growth. Similarly, a small source may ignite many items of furniture that are capable of sustained fire growth. Upholstered furniture can reach peak burning rates in less than 5 minutes. Furnishings have been associated with many multiple-death fires.(ABSTRACT TRUNCATED AT 250 WORDS)

Review of UCN 5,6 Fire PSA Model based on ANS Fire PRA Standard

International Nuclear Information System (INIS)

Yang, Joon Eon; Lee, Yoon Hwan

2006-12-01

Recently, under the de-regulation environment, nuclear industry has attempted various approaches to improve the economics of Nuclear Power Plants (NPP). This approach uses the fire risk and performance information to manage the resources effectively and efficiently that are used in the operation of NPP. In fire risk informed/performance-based decision/operation, fire PSA quality is one of the most important things. The nuclear industry and regulatory body of U.S.A have developed a measure to evaluate the quality of fire PSA. ANS (American Nuclear Society) has developed a guidance called 'ANS Fire PRA Methodology Standard'. However, in Korea, there have been no attempts to evaluate the quality of fire PSA model itself. Therefore, we cannot be sure about the quality of fire PSA whether or not the present fire PSA model can be used for the risk-informed applications such as mentioned above. We can say that the evaluation of fire PSA model quality is the basis for the fire risk informed/performance-based decision/operation. In this report, we have evaluated the quality of fire PSA model for Ulchin 5 and 6 units based on the ANS Fire PRA Standard. We, also, have derived what items are to be improved to upgrade the quality of fire PSA model and how it can be improved. This report can be used as the base of the fire risk informed/performance-based decision/operation work in Korea

Reduced frequency and severity of residential fires following delivery of fire prevention education by on-duty fire fighters: cluster randomized controlled study.

Science.gov (United States)

Clare, Joseph; Garis, Len; Plecas, Darryl; Jennings, Charles

2012-04-01

In 2008, Surrey Fire Services, British Columbia, commenced a firefighter-delivered, door-to-door fire-prevention education and smoke alarm examination/installation initiative with the intention of reducing the frequency and severity of residential structure fires in the City of Surrey. High-risk zones within the city were identified and 18,473 home visits were undertaken across seven temporal delivery cohorts (13.8% of non-apartment dwellings in the city). The frequency and severity of fires pre- and post- the home visit intervention was examined in comparison to randomized high-risk cluster controls. Overall, the frequency of fires was found to have reduced in the city overall, however, the reduction in the intervention cohorts was significantly larger than for controls. Furthermore, when fires did occur within the intervention cohorts, smoke detectors were activated more frequently and the fires were confined to the object of origin more often post-home visits. No equivalent pattern was observed for the cluster control. On-duty fire fighters can reduce the frequency and severity of residential fires through targeted, door-to-door distribution of fire prevention education in high-risk areas. Copyright © 2012 Elsevier Ltd. All rights reserved.

Fire test database

International Nuclear Information System (INIS)

Lee, J.A.

1989-01-01

This paper describes a project recently completed for EPRI by Impell. The purpose of the project was to develop a reference database of fire tests performed on non-typical fire rated assemblies. The database is designed for use by utility fire protection engineers to locate test reports for power plant fire rated assemblies. As utilities prepare to respond to Information Notice 88-04, the database will identify utilities, vendors or manufacturers who have specific fire test data. The database contains fire test report summaries for 729 tested configurations. For each summary, a contact is identified from whom a copy of the complete fire test report can be obtained. Five types of configurations are included: doors, dampers, seals, wraps and walls. The database is computerized. One version for IBM; one for Mac. Each database is accessed through user-friendly software which allows adding, deleting, browsing, etc. through the database. There are five major database files. One each for the five types of tested configurations. The contents of each provides significant information regarding the test method and the physical attributes of the tested configuration. 3 figs

Millennials in the Fire Service: The Effectiveness of Fire Service Recruiting, Testing, and Retention

Science.gov (United States)

2017-12-01

Administration/US-fire-department-profile. 50 Taro Yamane, Statistics : An Introductory Analysis, 2nd ed. (New York: Harper and Rowe, 1967), 886. 15...241096018-Is-there-a-better-approach-for-fire-department-testing/. Yamane, Taro. Statistics : An Introductory Analysis, 2nd ed. New York: Harper and...Fire Protection Association, January 2016), 21, http://www.nfpa.org/News-and-Research/Fire- statistics - and-reports/Fire- statistics /The-fire-service

Fire debris analysis for forensic fire investigation using laser induced breakdown spectroscopy (LIBS)

Science.gov (United States)

Choi, Soojin; Yoh, Jack J.

2017-08-01

The possibility verification of the first attempt to apply LIBS to arson investigation was performed. LIBS has capabilities for real time in-situ analysis and depth profiling. It can provide valuable information about the fire debris that are complementary to the classification of original sample components and combustion residues. In this study, fire debris was analyzed to determine the ignition source and existence of a fire accelerant using LIBS spectra and depth profiling analysis. Fire debris chemical composition and carbon layer thickness determines the possible ignition source while the carbon layer thickness of combusted samples represents the degree of sample carbonization. When a sample is combusted with fire accelerants, a thicker carbon layer is formed because the burning rate is increased. Therefore, depth profiling can confirm the existence of combustion accelerants, which is evidence of arson. Also investigation of fire debris by depth profiling is still possible when a fire is extinguished with water from fire hose. Such data analysis and in-situ detection of forensic signals via the LIBS may assist fire investigation at crime scenes.

Alternative approach for fire suppression of class A, B and C fires in gloveboxes

Energy Technology Data Exchange (ETDEWEB)

Rosenberger, Mark S [Los Alamos National Laboratory; Tsiagkouris, James A [Los Alamos National Laboratory

2011-02-10

Department of Energy (DOE) Orders and National Fire Protection Association (NFPA) Codes and Standards require fire suppression in gloveboxes. Several potential solutions have been and are currently being considered at Los Alamos National Laboratory (LANL). The objective is to provide reliable, minimally invasive, and seismically robust fire suppression capable of extinguishing Class A, B, and C fires; achieve compliance with DOE and NFPA requirements; and provide value-added improvements to fire safety in gloveboxes. This report provides a brief summary of current approaches and also documents the successful fire tests conducted to prove that one approach, specifically Fire Foe{trademark} tubes, is capable of achieving the requirement to provide reliable fire protection in gloveboxes in a cost-effective manner.

75 FR 221 - Airworthiness Directives; Fire Fighting Enterprises Limited Portable Halon 1211 Fire...

Science.gov (United States)

2010-01-05

... Airworthiness Directives; Fire Fighting Enterprises Limited Portable Halon 1211 Fire Extinguishers as Installed... specification, have been supplied to the aviation industry for use in fire extinguishing equipment. * * * * * * * * * * * This Halon 1211 has subsequently been used to fill certain FFE [Fire Fighting Enterprises] portable...

Large-scale pool fires

Directory of Open Access Journals (Sweden)

Steinhaus Thomas

2007-01-01

Full Text Available A review of research into the burning behavior of large pool fires and fuel spill fires is presented. The features which distinguish such fires from smaller pool fires are mainly associated with the fire dynamics at low source Froude numbers and the radiative interaction with the fire source. In hydrocarbon fires, higher soot levels at increased diameters result in radiation blockage effects around the perimeter of large fire plumes; this yields lower emissive powers and a drastic reduction in the radiative loss fraction; whilst there are simplifying factors with these phenomena, arising from the fact that soot yield can saturate, there are other complications deriving from the intermittency of the behavior, with luminous regions of efficient combustion appearing randomly in the outer surface of the fire according the turbulent fluctuations in the fire plume. Knowledge of the fluid flow instabilities, which lead to the formation of large eddies, is also key to understanding the behavior of large-scale fires. Here modeling tools can be effectively exploited in order to investigate the fluid flow phenomena, including RANS- and LES-based computational fluid dynamics codes. The latter are well-suited to representation of the turbulent motions, but a number of challenges remain with their practical application. Massively-parallel computational resources are likely to be necessary in order to be able to adequately address the complex coupled phenomena to the level of detail that is necessary.

The Effects of Vegetative Type, Edges, Fire History, Rainfall and Management in Fire-Maintained Ecosystems

Science.gov (United States)

Breininger, David R.; Foster, Tammy E.; Carter, Geoffrey M.; Duncan, Brean W.; Stolen, Eric D.; Lyon, James E.

2017-01-01

The combined effects of repeated fires, climate, and landscape features (e.g., edges) need greater focus in fire ecology studies, which usually emphasize characteristics of the most recent fire and not fire history. Florida scrub-jays are an imperiled, territorial species that prefer medium (1.2-1.7 m) shrub heights. We measured short, medium, and tall habitat quality states annually within 10 ha grid cells that represented potential territories because frequent fires and vegetative recovery cause annual variation in habitat quality. We used multistate models and model selection to test competing hypotheses about how transition probabilities between states varied annually as functions of environmental covariates. Covariates included vegetative type, edges, precipitation, openings (gaps between shrubs), mechanical cutting, and fire characteristics. Fire characteristics not only included an annual presenceabsence of fire covariate, but also fire history covariates: time since the previous fire, the maximum fire-free interval, and the number of repeated fires. Statistical models with support included many covariates for each transition probability, often including fire history, interactions and nonlinear relationships. Tall territories resulted from 28 years of fire suppression and habitat fragmentation that reduced the spread of fires across landscapes. Despite 35 years of habitat restoration and prescribed fires, half the territories remained tall suggesting a regime shift to a less desirable habitat condition. Measuring territory quality states and environmental covariates each year combined with multistate modeling provided a useful empirical approach to quantify the effects of repeated fire in combinations with environmental variables on transition probabilities that drive management strategies and ecosystem change.

Fire Stations

Data.gov (United States)

Department of Homeland Security — Fire Stations in the United States Any location where fire fighters are stationed or based out of, or where equipment that such personnel use in carrying out their...

Fire Risk Assessment in Germany

International Nuclear Information System (INIS)

Berg, H. P.

2000-01-01

Quantitative fire risk assessment can serve as an additional tool to assess the safety level of a nuclear power plant (NPP) and to set priorities for fire protection improvement measures. The recommended approach to be applied within periodic safety reviews of NPPs in Germany starts with a screening process providing critical fire zones in which a fully developed fire has the potential to both cause an initiating event and impair the function of at least one component or system critical to safety. The second step is to perform a quantitative analysis using a standard event tree has been developed with elements for fire initiation, ventilation of the room, fire detection, fire suppression, and fire propagation. In a final step, the fire induced frequency of initiating events, the main contributors and the calculated hazard state frequency for the fire event are determined. Results of the first quantitative fire risk studies performed in Germany are reported. (author)

The role of fire severity, distance from fire perimeter and vegetation on post-fire recovery of small-mammal communities in chaparal

Science.gov (United States)

Jay Diffendorfer; Genie M. Fleming; Scott Tremor; Wayne Spencer; Jan L. Beyers

2012-01-01

Chaparral shrublands in southern California, US, exhibit significant biodiversity but are prone to large, intense wildfires. Debate exists regarding fuel reduction to prevent such fires in wildland areas, but the effects of these fires on fauna are not well understood. We studied whether fire severity and distance from unburned fire perimeter influenced recovery of the...

Modeling of compartment fire

International Nuclear Information System (INIS)

Sathiah, P.; Siccama, A.; Visser, D.; Komen, E.

2011-01-01

Fire accident in a containment is a serious threat to nuclear reactors. Fire can cause substantial loss to life and property. The risk posed by fire can also exceed the risk from internal events within a nuclear reactor. Numerous research efforts have been performed to understand and analyze the phenomenon of fire in nuclear reactor and its consequences. Modeling of fire is an important subject in the field of fire safety engineering. Two approaches which are commonly used in fire modeling are zonal modeling and field modeling. The objective of this work is to compare zonal and field modeling approach against a pool fired experiment performed in a well-confined compartment. Numerical simulations were performed against experiments, which were conducted within PRISME program under the framework of OECD. In these experiments, effects of ventilation flow rate on heat release rate in a confined and mechanically ventilated compartment is investigated. Time dependent changes in gas temperature and oxygen mass fraction were measured. The trends obtained by numerical simulation performed using zonal model and field model compares well with experiments. Further validation is needed before this code can be used for fire safety analyses. (author)

Building 431 fire tests

International Nuclear Information System (INIS)

Alvares, N.J.; Beason, D.G.; Ford, H.W.; Magee, M.W.

1977-01-01

An extensive discussion of considerations for fire protection in the LLL mirror fusion test facility (MFTF) is presented. Because of the large volume and high bays of the building, sufficient data on fire detection is unavailable. Results of fire detection tests using controlled fire sources in the building are presented. Extensive data concerning the behavior of the building atmosphere are included. Candidate fire detection instrumentation and extinguishing systems for use in the building are briefly reviewed

The impact of state fire safe cigarette policies on fire fatalities, injuries, and incidents.

Science.gov (United States)

Folz, David H; Shults, Chris

Cigarettes are a leading cause of civilian deaths in home fires. Over the last decade, state fire service leaders and allied interest groups succeeded in persuading state lawmakers to require manufacturers to sell only low-ignition strength or "fire safe" cigarettes as a strategy to reduce these fatalities and the injuries and losses that stem from them. This article examines whether the states' fire safe cigarette laws actually helped to save lives, prevent injuries, and reduce the incidence of home fires ignited by cigarettes left unattended by smokers. Controlling for the effects of key demographic, social, economic, and housing variables, this study finds that the states' fire-safe cigarette policies had significant impacts on reducing the rate of smoking-related civilian fire deaths and the incidence of fires started by tobacco products. The findings also suggest that the states' fire safe cigarette policies may have helped to reduce the rate of smoking-related fire injuries. The study shows that collective actions by leaders in the fire service across the states can result in meaningful policy change that protects lives and advances public safety even when a political consensus for action is absent at the national level.

FIRE PROTECTION SYSTEMS AND TECHNOLOGIES

Directory of Open Access Journals (Sweden)

Aristov Denis Ivanovich

2016-03-01

Full Text Available The All-Russian Congress “Fire Stop Moscow” was de-voted to the analysis of the four segments of the industry of fire protection systems and technologies: the design of fire protec-tion systems, the latest developments and technologies of active and passive fire protection of buildings, the state and the devel-opment of the legal framework, the practice of fire protection of buildings and structures. The forum brought together the repre-sentatives of the industry of fire protection systems, scientists, leading experts, specialists in fire protection and representatives of construction companies from different regions of Russia. In parallel with the Congress Industrial Exhibition of fire protection systems, materials and technology was held, where manufacturers presented their products. The urgency of the “Fire Stop Moscow” Congress in 2015 organized by the Congress Bureau ODF Events lies primarily in the fact that it considered the full range of issues related to the fire protection of building and construction projects; studied the state of the regulatory framework for fire safety and efficiency of public services, research centers, private companies and busi-nesses in the area of fire safety. The main practical significance of the event which was widely covered in the media space, was the opportunity to share the views and information between management, science, and practice of business on implementing fire protection systems in the conditions of modern economic relations and market realities. : congress, fire protection, systems, technologies, fire protection systems, exhibition

Accelerated weathering of fire-retardant-treated wood for fire testing

Science.gov (United States)

Robert H. White

2009-01-01

Fire-retardant-treated products for exterior applications must be subjected to actual or accelerated weathering prior to fire testing. For fire-retardant-treated wood, the two accelerated weathering methods have been Method A and B of ASTM D 2898. The rain test is Method A of ASTM D 2898. Method B includes exposures to ultraviolet (UV) sunlamps in addition to water...

Rx fire laws: tools to protect fire: the `ecological imperative?

Science.gov (United States)

Dale Wade; Steven Miller; Johnny Stowe; James Brenner

2006-01-01

The South is the birthplace of statutes and ordinances that both advocate and protect the cultural heritage of woods burning, which has been practiced in this region uninterrupted for more than 10,000 years. We present a brief overview of fire use in the South and discuss why most southern states recognized early on that periodic fire was necessary to sustain fire...

THE REACTION TO FIRE TEST FOR FIRE RETARDANT AND FOR COMBUSTIBLE MATERIAL

Directory of Open Access Journals (Sweden)

Adelaida FANFAROVÁ

2016-12-01

Full Text Available Currently the natural materials become popular building material for houses, buildings and recreational property. The risk of fires in residential timber construction or eco houses cannot be completely ruled out, therefore there is a need for proper and correct implementing preventive measures and application of all available solutions, which may reduce the risk of fire as far as possible, to slow down the combustion process, to protect the life of people, animals and also the building itself until arrival members of the Fire and Rescue Services. Fireproofing of combustible materials is a specific area of fire protection. For scientific research as well as for real-life practice, not only their structural and physical properties, but also fire-technical characteristics are really important. The present researchers mostly focus on fire-retardant treatment of wood that is why the authors of this contribution focused on a different combustible material. This research article presents the experimental testing and examination of the reaction to fire test of the selected thermal insulation of hemp fiber that was impregnated by the selected fire retardant in laboratory conditions.

Wildland Fire Behaviour Case Studies and Fuel Models for Landscape-Scale Fire Modeling

Directory of Open Access Journals (Sweden)

Paul-Antoine Santoni

2011-01-01

Full Text Available This work presents the extension of a physical model for the spreading of surface fire at landscape scale. In previous work, the model was validated at laboratory scale for fire spreading across litters. The model was then modified to consider the structure of actual vegetation and was included in the wildland fire calculation system Forefire that allows converting the two-dimensional model of fire spread to three dimensions, taking into account spatial information. Two wildland fire behavior case studies were elaborated and used as a basis to test the simulator. Both fires were reconstructed, paying attention to the vegetation mapping, fire history, and meteorological data. The local calibration of the simulator required the development of appropriate fuel models for shrubland vegetation (maquis for use with the model of fire spread. This study showed the capabilities of the simulator during the typical drought season characterizing the Mediterranean climate when most wildfires occur.

Forest fires are changing: let’s change the fire management strategy

Directory of Open Access Journals (Sweden)

Bovio G

2017-08-01

Full Text Available Forest fires in Italy are changing. More frequent heatwaves and drought increase the flammability of the vegetation; the abandonment of rural land produces 30.000 ha of newly afforested areas each year; and the wildland-urban interface is expanding with the sprawl of urbanized areas. However, forest fires are rarely understood and managed in their complexity. The public opinion is often misinformed on the causes and consequences of fires in the forest. Moreover, fire management relies almost exclusively on extinction and emergency response, resulting in high costs and limited efficacy versus extreme fire seasons. We advocate to increase the role and investments in wildfire prevention, which can be carried out by fuel-oriented silviculture, such as facilitating less flammable species or prescribed burning, in order to reduce the flammability of the vegetation and mitigate fire intensity in high-leverage areas. A centralized structure is necessary to implement such a strategy and coordinate the competences and actions of all local administrations and actors involved.

Discovery Mondays - Men of fire: the fire brigade show their mettle

CERN Multimedia

2004-01-01

Flashover and backdraught, these technical terms refer to two of the most dangerous phenomena associated with fires. In order to train in dealing with them, in the course of their fire fighting duties the CERN fire brigade use special simulation equipment. The demonstrations are rather spectacular... Thrills are therefore guaranteed at the next Discovery Monday on 2 February! In the course of the evening, you will see fire-fighters demonstrate climbing techniques including abseiling, a method they would have to use to access underground structures on the CERN site in the event of an accident. The accomplished climbers (the Hazardous Environments Response Team) will provide detailed explanations of the rescue techniques and procedures they use in tunnels and hazardous environments. However, the remit of the CERN fire brigade goes well beyond fire-fighting. It ranges from monitoring confined spaces to dealing with flooding and preventing chemical hazards. A wide range of equipment enables them to fulfil thei...

Fire Source Accessibility of Water Mist Fire Suppression Improvement through Flow Method Control

Energy Technology Data Exchange (ETDEWEB)

Jung, Jun Ho; Kim, Hyeong Taek; Kim, Yun Jung; Park, Mun Hee [KHNP CRI, Daejeon (Korea, Republic of)

2013-10-15

Recently, nuclear power plants set CO{sub 2} fire suppression system. However it is hard to establish and to maintain and it also has difficulties performing function test. Therefore, it needs to develop a new fire suppression system to replace the existing CO{sub 2} fire suppression systems in nuclear power plant. In fact, already, there exist alternatives - gas fire suppression system or clean fire extinguishing agent, but it is hard to apply because it requires a highly complicated plan. However, water mist fire suppression system which has both water system and gas system uses small amount of water and droplet, so it is excellent at oxygen displacement and more suitable for nuclear power plant because it can avoid second damage caused by fire fighting water. This paper explains about enclosure effect of water mist fire suppression. And it suggests a study direction about water mist fire source approach improvement and enclosure effect improvement, using flow method control of ventilation system. Water mist fire suppression can be influenced by various variable. And flow and direction of ventilation system are important variable. Expectations of the plan for more fire source ventilation system is as in the following. It enhances enclosure effects of water mists, so it improves extinguish performance. Also the same effect as a inert gas injection causes can be achieved. Lastly, it is considered that combustible accessibility of water mists will increase because of descending air currents.

Factors controlling seedling germination after fire in Mediterranean gorse shrublands. Implications for fire prescription.

Science.gov (United States)

De Luis, M; Raventós, J; González-Hidalgo, J C

2005-07-01

In Western Mediterranean areas, fires are frequent in forests established on old croplands where woody resprouting species are scarce and post-fire regeneration is limited to obligate-seeder species, such as Mediterranean gorse (Ulex parviflorus), that accumulate a great deal of fine dry fuel, increasing the risk of other severe fires. Under these conditions, fuel control techniques are required in order to prevent fires of high intensity and severity and the subsequent economic and ecological damage. Prescribed fires present an alternative to fuel control, and recent studies demonstrate that, under optimum climatic conditions, fire-line intensity values fall within the limits of those recommended for fire prescription. However, a better understanding of the consequences of fire on the regeneration of vegetation is needed in order to evaluate the suitability of prescribed fires as a technique for fuel reduction in Mediterranean gorse ecosystems. This paper analyses the factors controlling seedling germination after fire to make an evaluation from an ecological perspective of whether fire prescription is a suitable technique for fuel control in mature Mediterranean gorse shrublands. The results show that small differences in the composition of vegetation play a decisive role in fire behaviour, and have a decisive influence on the system's capacity for regeneration. Fire severity is low in mixed Mediterranean gorse communities with a low continuity of dead fine fuel (including Cistus sp., Rosmarinus sp., etc.) and fire creates a wide range of microhabitats where seedling emergence is high. In contrast, where U. parviflorus is more dominant, fire severity is higher and the regeneration of vegetation could be hindered. Our conclusions suggest that detailed studies of the composition of plant communities are required in order to decide whether prescribed burning should be applied.

Cinema Fire Modelling by FDS

International Nuclear Information System (INIS)

Glasa, J; Valasek, L; Weisenpacher, P; Halada, L

2013-01-01

Recent advances in computer fluid dynamics (CFD) and rapid increase of computational power of current computers have led to the development of CFD models capable to describe fire in complex geometries incorporating a wide variety of physical phenomena related to fire. In this paper, we demonstrate the use of Fire Dynamics Simulator (FDS) for cinema fire modelling. FDS is an advanced CFD system intended for simulation of the fire and smoke spread and prediction of thermal flows, toxic substances concentrations and other relevant parameters of fire. The course of fire in a cinema hall is described focusing on related safety risks. Fire properties of flammable materials used in the simulation were determined by laboratory measurements and validated by fire tests and computer simulations

Cinema Fire Modelling by FDS

Science.gov (United States)

Glasa, J.; Valasek, L.; Weisenpacher, P.; Halada, L.

2013-02-01

Recent advances in computer fluid dynamics (CFD) and rapid increase of computational power of current computers have led to the development of CFD models capable to describe fire in complex geometries incorporating a wide variety of physical phenomena related to fire. In this paper, we demonstrate the use of Fire Dynamics Simulator (FDS) for cinema fire modelling. FDS is an advanced CFD system intended for simulation of the fire and smoke spread and prediction of thermal flows, toxic substances concentrations and other relevant parameters of fire. The course of fire in a cinema hall is described focusing on related safety risks. Fire properties of flammable materials used in the simulation were determined by laboratory measurements and validated by fire tests and computer simulations

How to generate and interpret fire characteristics charts for surface and crown fire behavior

Science.gov (United States)

Patricia L. Andrews; Faith Ann Heinsch; Luke Schelvan

2011-01-01

A fire characteristics chart is a graph that presents primary related fire behavior characteristics-rate of spread, flame length, fireline intensity, and heat per unit area. It helps communicate and interpret modeled or observed fire behavior. The Fire Characteristics Chart computer program plots either observed fire behavior or values that have been calculated by...

Aerosol generation from Kerosene fires

International Nuclear Information System (INIS)

Jordan, S.; Lindner, W.

1981-01-01

The course of solvent surface fires is dependent on the surface area on fire; depth of pool and solvent composition do not influence the fire rate. But the fire rate increases rapidly with the burning area. The residual oxygen concentration after a fire in a closed container is dependent on the violence of the fire, i.e. on the burning surface. Moreover the ending of the fire is influenced by the TBP-concentration of the solvent. With sufficient supply of solvent the TBP-concentration changes only slightly during the fire, so that a fire at 14% O 2 -concentration is extinguished within the container. With the TBP-concentration changing considerably, i.e. little mass, a fire with a similar burning surface is already extinguished at an O 2 -content of 18%. The aerosol generation depends on the fire rate, and so it is higher in free atmosphere than in closed containers. The soot production in the mixture fire (kerosene /TBP 70/30) is higher by a factor 7 than in the pure kerosene fire. Primary soot-particles have a diameter of approximately 0,05 μm and agglomerate rapidly into aggregates of 0,2-0,4 μm. (orig.) [de

Fire safety engineering

International Nuclear Information System (INIS)

Smith, D.N.

1989-01-01

The periodic occurrence of large-scale, potentially disastrous industrial accidents involving fire in hazardous environments such as oilwell blowouts, petrochemical explosions and nuclear installations highlights the need for an integrated approach to fire safety engineering. Risk reduction 'by design' and rapid response are of equal importance in the saving of life and property in such situations. This volume of papers covers the subject thoroughly, touching on such topics as hazard analysis, safety design and testing, fire detection and control, and includes studies of fire hazard in the context of environment protection. (author)

Fires, ecological effects of

Science.gov (United States)

W. J. Bond; Robert Keane

2017-01-01

Fire is both a natural and anthropogenic disturbance influencing the distribution, structure, and functioning of terrestrial ecosystems around the world. Many plants and animals depend on fire for their continued existence. Others species, such as rainforest plants species, are extremely intolerant of burning and need protection from fire. The properties of a fire...

Combined use of weather forecasting and satellite remote sensing information for fire risk, fire and fire impact monitoring

Directory of Open Access Journals (Sweden)

Wolfgang Knorr

2011-06-01

Full Text Available The restoration of fire-affected forest areas needs to be combined with their future protection from renewed catastrophic fires, such as those that occurred in Greece during the 2007 summer season. The present work demonstrates that the use of various sources of satellite data in conjunction with weather forecast information is capable of providing valuable information for the characterization of fire danger with the purpose of protecting the Greek national forest areas. This study shows that favourable meteorological conditions have contributed to the fire outbreak during the days of the unusually damaging fires in Peloponnese as well as Euboia (modern Greek: Evia at the end of August 2007. During those days, Greece was located between an extended high pressure system in Central Europe and a low pressure system in the Middle East. Their combination resulted in strong north-northeasterly winds in the Aegean Sea. As a consequence, strong winds were also observed in the regions of Evia and Peloponnese, especially in mountainous areas. The analysis of satellite images showing smoke emitted from the fires corroborates the results from the weather forecasts. A further analysis using the Fraction of Absorbed Photosyntetically Active Radiation (FAPAR as an indicator of active vegetation shows the extent of the destruction caused by the fire. The position of the burned areas coincides with that of the active fires detected in the earlier satellite image. Using the annual maximum FAPAR as an indicator of regional vegetation density, it was found that only regions with relatively high FAPAR were burned.

Sodium fires in nuclear facilities

International Nuclear Information System (INIS)

Menzenhauer, P.

1974-01-01

The work deals with the behaviour of liquid sodium when it comes into contact with air, especially in the course of fires in technical plants. The most important fire procedures are constructed as realistically as possible, that is to say that the fires were not only carried out on a laboratory scale but with quantities of up to 200 kg sodium at temperatures of up to 800 0 C. The following was investigated: 1) the course of the fire in rooms, 2) restriction of the fire, 3) removal of the burnt remains, 4) protection measures. The fire was varied in its most important physical appearance such as surface fire, spurt fire and fire on isolated pipe lines. The fires were checked by precautionary, contructive measures - it was not necessary to place persons at the site of the fire - and by active measures such as for example by covering with extinguishing powder. All important test phases were captured in film and slides series. Visible material is thus available for the operation team of sodium plants and fire brigades who might possibly be called upon. (orig./LH) [de

Corrosion and Materials Performance in biomass fired and co-fired power plants

DEFF Research Database (Denmark)

Montgomery, Melanie; Larsen, OH; Biede, O

2003-01-01

not previously encountered in coal-fired power plants. The type of corrosion attack can be directly ascribed to the composition of the deposit and the metal surface temperature. In woodchip boilers, a similar corrosion rate and corrosion mechanism has on some occasions been observed. Co-firing of straw (10...... and 20% energy basis) with coal has shown corrosion rates lower than those in straw-fired plants. With both 10 and 20% straw, no chlorine corrosion was seen. This paper will describe the results from in situ investigations undertaken in Denmark on high temperature corrosion in biomass fired plants....... Results from 100% straw-firing, woodchip and co-firing of straw with coal will be reported. The corrosion mechanisms observed are summarized and the corrosion rates for 18-8 type stainless steels are compared....

WRF-Fire: coupled weather-wildland fire modeling with the weather research and forecasting model

Science.gov (United States)

Janice L. Coen; Marques Cameron; John Michalakes; Edward G. Patton; Philip J. Riggan; Kara M. Yedinak

2012-01-01

A wildland fire behavior module (WRF-Fire) was integrated into the Weather Research and Forecasting (WRF) public domain numerical weather prediction model. The fire module is a surface fire behavior model that is two-way coupled with the atmospheric model. Near-surface winds from the atmospheric model are interpolated to a finer fire grid and used, with fuel properties...

The economics of fire protection

CERN Document Server

Ramachandran, Ganapathy

2003-01-01

This important new book, the first of its kind in the fire safety field, discusses the economic problems faced by decision-makers in the areas of fire safety and fire precautions. The author considers the theoretical aspects of cost-benefit analysis and other relevant economic problems with practical applications to fire protection systems. Clear examples are included to illustrate these techniques in action. The work covers: * the performance and effectiveness of passive fire protection measures such as structural fire resistance and means of escape facilities, and active systems such as sprinklers and detectors * the importance of educating for better understanding and implementation of fire prevention through publicity campaigns and fire brigade operations * cost-benefit analysis of fire protection measures and their combinations, taking into account trade-offs between these measures. The book is essential reading for consultants and academics in construction management, economics and fire safety, as well ...

FIRE HAZARDS ANALYSIS - BUSTED BUTTE

International Nuclear Information System (INIS)

Longwell, R.; Keifer, J.; Goodin, S.

2001-01-01

The purpose of this fire hazards analysis (FHA) is to assess the risk from fire within individual fire areas at the Busted Butte Test Facility and to ascertain whether the DOE fire safety objectives are met. The objective, identified in DOE Order 420.1, Section 4.2, is to establish requirements for a comprehensive fire and related hazards protection program for facilities sufficient to minimize the potential for: (1) The occurrence of a fire related event. (2) A fire that causes an unacceptable on-site or off-site release of hazardous or radiological material that will threaten the health and safety of employees. (3) Vital DOE programs suffering unacceptable interruptions as a result of fire and related hazards. (4) Property losses from a fire and related events exceeding limits established by DOE. Critical process controls and safety class systems being damaged as a result of a fire and related events

Subsurface Fire Hazards Technical Report

International Nuclear Information System (INIS)

Logan, R.C.

1999-01-01

The results from this report are preliminary and cannot be used as input into documents supporting procurement, fabrication, or construction. This technical report identifies fire hazards and proposes their mitigation for the subsurface repository fire protection system. The proposed mitigation establishes the minimum level of fire protection to meet NRC regulations, DOE fire protection orders, that ensure fire containment, adequate life safety provisions, and minimize property loss. Equipment requiring automatic fire suppression systems is identified. The subsurface fire hazards that are identified can be adequately mitigated

Using the Large Fire Simulator System to map wildland fire potential for the conterminous United States

Science.gov (United States)

LaWen Hollingsworth; James Menakis

2010-01-01

This project mapped wildland fire potential (WFP) for the conterminous United States by using the large fire simulation system developed for Fire Program Analysis (FPA) System. The large fire simulation system, referred to here as LFSim, consists of modules for weather generation, fire occurrence, fire suppression, and fire growth modeling. Weather was generated with...

WRF-Fire Applied in Bulgaria

OpenAIRE

Dobrinkova, Nina; Jordanov, Georgi; Mandel, Jan

2010-01-01

WRF-Fire consists of the WRF (Weather Research and Forecasting Model) coupled with a fire spread model, based on the level-set method. We describe a preliminary application of WRF-Fire to a forest fire in Bulgaria, oportunities for research of forest fire models for Bulgaria, and plans for the development of an Environmental Decision Support Systems which includes computational modeling of fire behavior.

The fire brigade renovates

CERN Multimedia

2002-01-01

The new fire engine at CERN's Fire Station. A shiny brand-new fire engine is now attracting all the attention of the members of CERN's fire brigade. Since the beginning of last week this engine has taken over from an 18-year-old one, which has now been 'retired' from service. This modern vehicle, built in Brescia, Italy, is much lighter and more powerful than the old one and is equipped to allow the fire service to tackle most call-outs without the support of at least one other vehicle, as is currently necessary. The new fire engine is designed to transport six fire-fighters, 2000 litres of water, and is equipped not only for fire fighting actions but also to respond initially to any other kind of call-out, such as traffic accidents, chemical incidents, pollution, lightning, etc. It goes almost without saying that it is provided with the most modern safety measures, a low centre of gravity, as well as a special chassis and a combination pump (low and high pressure), which improve the safety and performance ...

Fire analog: a comparison between fire plumes and energy center cooling tower plumes

Energy Technology Data Exchange (ETDEWEB)

Orgill, M.M.

1977-10-01

Thermal plumes or convection columns associated with large fires are compared to thermal plumes from cooling towers and proposed energy centers to evaluate the fire analog concept. Energy release rates of mass fires are generally larger than for single or small groups of cooling towers but are comparable to proposed large energy centers. However, significant physical differences exist between cooling tower plumes and fire plumes. Cooling tower plumes are generally dominated by ambient wind, stability and turbulence conditions. Fire plumes, depending on burning rates and other factors, can transform into convective columns which may cause the fire behavior to become more violent. This transformation can cause strong inflow winds and updrafts, turbulence and concentrated vortices. Intense convective columns may interact with ambient winds to create significant downwind effects such as wakes and Karman vortex streets. These characteristics have not been observed with cooling tower plumes to date. The differences in physical characteristics between cooling tower and fire plumes makes the fire analog concept very questionable even though the approximate energy requirements appear to be satisfied in case of large energy centers. Additional research is suggested in studying the upper-level plume characteristics of small experimental fires so this information can be correlated with similar data from cooling towers. Numerical simulation of fires and proposed multiple cooling tower systems could also provide comparative data.

Specialists' meeting on sodium fires

International Nuclear Information System (INIS)

Kozlov, F.A.; Kuznetsova, R.I.

1989-01-01

The four sessions of the meeting covered the following topics: 1. general approach to fast reactor safety, standards of fire safety, maximum design basis accidents for sodium leaks and fires, status of sodium fires in different countries; 2. physical and chemical processes during combustion of sodium and its interaction with structural and technological materials and methods for structural protection; 3. methods of sodium fires extinguishing and measures for localizing aerosol combustion products, organization of fire fighting procedures, instruction and training of fire personnel; 4. elimination of the consequences of sodium fires

Specialists' meeting on sodium fires

Energy Technology Data Exchange (ETDEWEB)

Kozlov, F A; Kuznetsova, R I [eds.

1989-07-01

The four sessions of the meeting covered the following topics: 1. general approach to fast reactor safety, standards of fire safety, maximum design basis accidents for sodium leaks and fires, status of sodium fires in different countries; 2. physical and chemical processes during combustion of sodium and its interaction with structural and technological materials and methods for structural protection; 3. methods of sodium fires extinguishing and measures for localizing aerosol combustion products, organization of fire fighting procedures, instruction and training of fire personnel; 4. elimination of the consequences of sodium fires.