WorldWideScience

Sample records for volatile flammable materials

  1. Selected Parametric Effects on Materials Flammability Limits

    Science.gov (United States)

    Hirsch, David B.; Juarez, Alfredo; Peyton, Gary J.; Harper, Susana A.; Olson, Sandra L.

    2011-01-01

    NASA-STD-(I)-6001B Test 1 is currently used to evaluate the flammability of materials intended for use in habitable environments of U.S. spacecraft. The method is a pass/fail upward flame propagation test conducted in the worst case configuration, which is defined as a combination of a material s thickness, test pressure, oxygen concentration, and temperature that make the material most flammable. Although simple parametric effects may be intuitive (such as increasing oxygen concentrations resulting in increased flammability), combinations of multi-parameter effects could be more complex. In addition, there are a variety of material configurations used in spacecraft. Such configurations could include, for example, exposed free edges where fire propagation may be different when compared to configurations commonly employed in standard testing. Studies involving combined oxygen concentration, pressure, and temperature on flammability limits have been conducted and are summarized in this paper. Additional effects on flammability limits of a material s thickness, mode of ignition, burn-length criteria, and exposed edges are presented. The information obtained will allow proper selection of ground flammability test conditions, support further studies comparing flammability in 1-g with microgravity and reduced gravity environments, and contribute to persuasive scientific cases for rigorous space system fire risk assessments.

  2. Unmanned Vehicle Material Flammability Test

    Science.gov (United States)

    Urban, David; Ruff, Gary A.; Fernandez-Pello, A. Carlos; T’ien, James S.; Torero, Jose L.; Cowlard, Adam; Rouvreau, Sebastian; Minster, Olivier; Toth, Balazs; Legros, Guillaume; Eigenbrod, Christian; Smirnov, Nickolay; Fujita, Osamu; Jomaas, Grande

    2013-01-01

    Microgravity combustion phenomena have been an active area of research for the past 3 decades however, there have been very few experiments directly studying spacecraft fire safety under low-gravity conditions. Furthermore, none of these experiments have studied sample and environment sizes typical of those expected in a spacecraft fire. All previous experiments have been limited to samples of the order of 10 cm in length and width or smaller. Terrestrial fire safety standards for all other habitable volumes on earth, e.g. mines, buildings, airplanes, ships, etc., are based upon testing conducted with full-scale fires. Given the large differences between fire behavior in normal and reduced gravity, this lack of an experimental data base at relevant length scales forces spacecraft designers to base their designs using 1-g understanding. To address this question a large scale spacecraft fire experiment has been proposed by an international team of investigators. This poster presents the objectives, status and concept of this collaborative international project to examine spacecraft material flammability at realistic scales. The concept behind this project is to utilize an unmanned spacecraft such as Orbital Cygnus vehicle after it has completed its delivery of cargo to the ISS and it has begun its return journey to earth. This experiment will consist of a flame spread test involving a meter scale sample ignited in the pressurized volume of the spacecraft and allowed to burn to completion while measurements are made. A computer modeling effort will complement the experimental effort. Although the experiment will need to meet rigorous safety requirements to ensure the carrier vehicle does not sustain damage, the absence of a crew removes the need for strict containment of combustion products. This will facilitate the examination of fire behavior on a scale that is relevant to spacecraft fire safety and will provide unique data for fire model validation. This will be

  3. ISO 14624 Series - Space Systems - Safety and Compatibility of Materials Flammability Assessment of Spacecraft Materials

    Science.gov (United States)

    Hirsch, David B.

    2007-01-01

    A viewgraph presentation on the flammability of spacecraft materials is shown. The topics include: 1) Spacecraft Fire Safety; 2) Materials Flammability Test; 3) Impetus for enhanced materials flammability characterization; 4) Exploration Atmosphere Working Group Recommendations; 5) Approach; and 6) Status of implementation

  4. Experimental and Modeling Study of the Flammability of Fuel Tank Headspace Vapors from Ethanol/Gasoline Fuels; Phase 3: Effects of Winter Gasoline Volatility and Ethanol Content on Blend Flammability; Flammability Limits of Denatured Ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Gardiner, D. P.; Bardon, M. F.; Clark, W.

    2011-07-01

    This study assessed differences in headspace flammability for summertime gasolines and new high-ethanol content fuel blends. The results apply to vehicle fuel tanks and underground storage tanks. Ambient temperature and fuel formulation effects on headspace vapor flammability of ethanol/gasoline blends were evaluated. Depending on the degree of tank filling, fuel type, and ambient temperature, fuel vapors in a tank can be flammable or non-flammable. Pure gasoline vapors in tanks generally are too rich to be flammable unless ambient temperatures are extremely low. High percentages of ethanol blended with gasoline can be less volatile than pure gasoline and can produce flammable headspace vapors at common ambient temperatures. The study supports refinements of fuel ethanol volatility specifications and shows potential consequences of using noncompliant fuels. E85 is flammable at low temperatures; denatured ethanol is flammable at warmer temperatures. If both are stored at the same location, one or both of the tanks' headspace vapors will be flammable over a wide range of ambient temperatures. This is relevant to allowing consumers to splash -blend ethanol and gasoline at fueling stations. Fuels compliant with ASTM volatility specifications are relatively safe, but the E85 samples tested indicate that some ethanol fuels may produce flammable vapors.

  5. Space Systems - Safety and Compatibility of Materials - Method to Determine the Flammability Thresholds of Materials

    Science.gov (United States)

    Hirsch, David

    2009-01-01

    Spacecraft fire safety emphasizes fire prevention, which is achieved primarily through the use of fire-resistant materials. Materials selection for spacecraft is based on conventional flammability acceptance tests, along with prescribed quantity limitations and configuration control for items that are non-pass or questionable. ISO 14624-1 and -2 are the major methods used to evaluate flammability of polymeric materials intended for use in the habitable environments of spacecraft. The methods are upward flame-propagation tests initiated in static environments and using a well-defined igniter flame at the bottom of the sample. The tests are conducted in the most severe flaming combustion environment expected in the spacecraft. The pass/fail test logic of ISO 14624-1 and -2 does not allow a quantitative comparison with reduced gravity or microgravity test results; therefore their use is limited, and possibilities for in-depth theoretical analyses and realistic estimates of spacecraft fire extinguishment requirements are practically eliminated. To better understand the applicability of laboratory test data to actual spacecraft environments, a modified ISO 14624 protocol has been proposed that, as an alternative to qualifying materials as pass/fail in the worst-expected environments, measures the actual upward flammability limit for the material. A working group established by NASA to provide recommendations for exploration spacecraft internal atmospheres realized the importance of correlating laboratory data with real-life environments and recommended NASA to develop a flammability threshold test method. The working group indicated that for the Constellation Program, the flammability threshold information will allow NASA to identify materials with increased flammability risk from oxygen concentration and total pressure changes, minimize potential impacts, and allow for development of sound requirements for new spacecraft and extravehicular landers and habitats

  6. Evaluating Material Flammability in Microgravity and Martian Gravity Compared to the NASA Standard Normal Gravity Test

    Science.gov (United States)

    Oslon, Sandra. L.; Ferkul, Paul

    2012-01-01

    Drop tower tests are conducted at Martian gravity to determine the flammability of three materials compared to previous tests in other normal gravity and reduced gravity environments. The comparison is made with consideration of a modified NASA standard test protocol. Material flammability limits in the different gravity and flow environments are tabulated to determine the factor of safety associated with normal gravity flammability screening. Previous testing at microgravity and Lunar gravity indicated that some materials burned to lower oxygen concentrations in low gravity than in normal gravity, although the low g extinction limit criteria are not the same as 1g due to time constraints in drop testing. Similarly, the data presented in this paper for Martian gravity suggest that there is a gravity level below Earth s at which materials burn more readily than on Earth. If proven for more materials, this may indicate the need to include a factor of safety on 1g flammability limits.

  7. TECHNICAL JUSTIFICATION FOR CHOOSING PROPANE AS A CALIBRATION AGENT FOR TOTAL FLAMMABLE VOLATILE ORGANIC COMPOUND (VOC) DETERMINATIONS

    Energy Technology Data Exchange (ETDEWEB)

    DOUGLAS, J.G.

    2006-07-06

    This document presents the technical justification for choosing and using propane as a calibration standard for estimating total flammable volatile organic compounds (VOCs) in an air matrix. A propane-in-nitrogen standard was selected based on a number of criteria: (1) has an analytical response similar to the VOCs of interest, (2) can be made with known accuracy and traceability, (3) is available with good purity, (4) has a matrix similar to the sample matrix, (5) is stable during storage and use, (6) is relatively non-hazardous, and (7) is a recognized standard for similar analytical applications. The Waste Retrieval Project (WRP) desires a fast, reliable, and inexpensive method for screening the flammable VOC content in the vapor-phase headspace of waste containers. Table 1 lists the flammable VOCs of interest to the WRP. The current method used to determine the VOC content of a container is to sample the container's headspace and submit the sample for gas chromatography--mass spectrometry (GC-MS) analysis. The driver for the VOC measurement requirement is safety: potentially flammable atmospheres in the waste containers must be allowed to diffuse prior to processing the container. The proposed flammable VOC screening method is to inject an aliquot of the headspace sample into an argon-doped pulsed-discharge helium ionization detector (Ar-PDHID) contained within a gas chromatograph. No actual chromatography is performed; the sample is transferred directly from a sample loop to the detector through a short, inert transfer line. The peak area resulting from the injected sample is proportional to the flammable VOC content of the sample. However, because the Ar-PDHID has different response factors for different flammable VOCs, a fundamental assumption must be made that the agent used to calibrate the detector is representative of the flammable VOCs of interest that may be in the headspace samples. At worst, we desire that calibration with the selected

  8. Non-Toxic, Non-Flammable, -80 C Phase Change Materials

    Science.gov (United States)

    Cutbirth, J. Michael

    2013-01-01

    The objective of this effort was to develop a non-toxic, non-flammable, -80 C phase change material (PCM) to be used in NASA's ICEPAC capsules for biological sample preservation in flight to and from Earth orbit. A temperature of about -68 C or lower is a critical temperature for maintaining stable cell, tissue, and cell fragment storage.

  9. Cleaning and materials compatibility test results for elimination of flammable solvents in wipe applications.

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, Edwin Paul

    2005-06-01

    In recent years, efforts have been made within the nuclear weapons complex (National Nuclear Security Administration) of the Department of Energy (DOE) to replace Resource Conservation and Recovery Act (RCRA) regulated solvents (i.e., flammable, toxic, corrosive, and reactive) and ozone-depleting chemicals (ODC) with more benign alternatives. Within the National Nuclear Security Administration (NNSA) and the Department of Defense (DoD) sectors, these solvents are used for cleaning hardware during routine maintenance operations. A primary goal of this study is to replace flammable solvents used in wiping applications. Two cleaners, including a hydrofluoroether (HFE) and an azeotrope of the HFE and isopropyl alcohol (IPA), have been studied as potential replacements for flammable solvents. Cleaning efficacy, short-term and long-term materials compatibility, corrosion, drying times, flammability, environment, safety and health (ES&H) and accelerated aging issues were among the experiments used to screen candidate solvents by the interagency team performing this work. This report presents cleaning efficacy results as determined by the contact angle Goniometer as well as materials compatibility results of various metal alloys and polymers. The results indicate that IPA (baseline cleaner) and the HFE/IPA azeotrope are roughly equivalent in their ability to remove fluorinated grease, silicone grease, and a simulated finger print contaminant from various metal alloys. All of the ASTM sandwich and immersion corrosion tests with IPA, HFE or the HFE/IPA azeotrope on metal alloys showed no signs of corrosion. Furthermore, no deleterious effects were noted for polymeric materials immersed in IPA, HFE, or the HFE/IPA azeotrope.

  10. Up in flames: a flammability assessment of alcohol-based hand sanitizers on common perioperative materials

    OpenAIRE

    Samuel Almengor; W. Patrick Monaghan; Jacksonville, FL

    2015-01-01

    Introduction: The objective of this study was to perform a flammability assessment of alcohol-based hand sanitizers on common perioperative materials. There is an estimated 550–650 surgical fires that occur nationally each year, an instance comparable to that of wrong-site surgery, yet only about 100 operating room fires are reported each year.  The median cost of an OR fire settlement claim is $120,166.  Generation of fire requires the presence of three components, known as the “fire triad”:...

  11. Volatile components and continental material of planets

    Science.gov (United States)

    Florenskiy, K. P.; Nikolayeva, O. V.

    1986-01-01

    It is shown that the continental material of the terrestrial planets varies in composition from planet to planet according to the abundances and composition of true volatiles (H20, CO2, etc.) in the outer shells of the planets. The formation of these shells occurs very early in a planet's evolution when the role of endogenous processes is indistinct and continental materials are subject to melting and vaporizing in the absence of an atmosphere. As a result, the chemical properties of continental materials are related not only to fractionation processes but also to meltability and volatility. For planets retaining a certain quantity of true volatile components, the chemical transformation of continental material is characterized by a close interaction between impact melting vaporization and endogeneous geological processes.

  12. 16 CFR 1500.43a - Method of test for flashpoint of volatile flammable materials.

    Science.gov (United States)

    2010-01-01

    ... (cooling) fluid is solid carbon dioxide (dry ice) and acetone. If the refrigerant charged cooling module is... test flame, are required. These flames may be fueled by piped gas service. A gage ring 4mm (5/32 in...

  13. Flammability Control In A Nuclear Waste Vitrification System

    Energy Technology Data Exchange (ETDEWEB)

    Zamecnik, John R.; Choi, Alexander S.; Johnson, Fabienne C.; Miller, Donald H.; Lambert, Daniel P.; Stone, Michael E.; Daniel, William E. Jr.

    2013-07-25

    The Defense Waste Processing Facility at the Savannah River Site processes high-level radioactive waste from the processing of nuclear materials that contains dissolved and precipitated metals and radionuclides. Vitrification of this waste into borosilicate glass for ultimate disposal at a geologic repository involves chemically modifying the waste to make it compatible with the glass melter system. Pretreatment steps include removal of excess aluminum by dissolution and washing, and processing with formic and nitric acids to: 1) adjust the reduction-oxidation (redox) potential in the glass melter to reduce radionuclide volatility and improve melt rate; 2) adjust feed rheology; and 3) reduce by steam stripping the amount of mercury that must be processed in the melter. Elimination of formic acid in pretreatment has been studied to eliminate the production of hydrogen in the pretreatment systems, which requires nuclear grade monitoring equipment. An alternative reductant, glycolic acid, has been studied as a substitute for formic acid. However, in the melter, the potential for greater formation of flammable gases exists with glycolic acid. Melter flammability is difficult to control because flammable mixtures can be formed during surges in offgases that both increase the amount of flammable species and decrease the temperature in the vapor space of the melter. A flammable surge can exceed the 60% of the LFL with no way to mitigate it. Therefore, careful control of the melter feed composition based on scaled melter surge testing is required. The results of engineering scale melter tests with the formic-nitric flowsheet and the use of these data in the melter flammability model are presented.

  14. Water Vapor-Mediated Volatilization of High-Temperature Materials

    Science.gov (United States)

    Meschter, Peter J.; Opila, Elizabeth J.; Jacobson, Nathan S.

    2013-07-01

    Volatilization in water vapor-containing atmospheres is an important and often unexpected mechanism of degradation of high-temperature materials during processing and in service. Thermodynamic properties data sets for key (oxy)hydroxide vapor product species that are responsible for material transport and damage are often uncertain or unavailable. Estimation, quantum chemistry calculation, and measurement methods for thermodynamic properties of these species are reviewed, and data judged to be reliable are tabulated and referenced. Applications of water vapor-mediated volatilization include component and coating recession in turbine engines, oxidation/volatilization of ferritic steels in steam boilers, chromium poisoning in solid-oxide fuel cells, vanadium transport in hot corrosion and degradation of hydrocracking catalysts, Na loss from Na β"-Al2O3 tubes, and environmental release of radioactive isotopes in a nuclear reactor accident or waste incineration. The significance of water vapor-mediated volatilization in these applications is described.

  15. 一种易燃易爆物自动阻断系统的研究%Study on the Automatic Blocking System of Flammable and Explosive Materials

    Institute of Scientific and Technical Information of China (English)

    高影; 孙慧松; 张晓峰; 曹井新

    2015-01-01

    目前,火灾状态下绝大多数的阻断系统是采用耐高温箱体对易燃易爆物进行隔离,但由于箱体的导热特点,导致易燃易爆物在高温的状态下会直接发生爆炸.该课题针对以上问题,设计一套自动阻断系统,将易燃易爆物放置于耐高温箱体中,火灾发生时形成真空隔离带,并利用无线技术发出火灾报警信息.%At present, in the fire condition, the majority of blocking systems are using high temperature resistant boxes to isolate the flammable and explosive materials. But because of the heat conduction characteristics of boxes, it will lead to the explosion of flammable and explosive materials in high temperature. In view of the problem above, this paper designs a set of automatic blocking system. Place flammable and explosive materials in the high temperature boxes and the vacuum isolation belt is formed when the fire occurs. And use wireless technology to produce fire alarm messages.

  16. Summary Report for the Development of Materials for Volatile Radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    Strachan, Denis M.; Chun, Jaehun; Henager, Charles H.; Matyas, Josef; Riley, Brian J.; Ryan, Joseph V.; Thallapally, Praveen K.

    2010-11-22

    The materials development summarized here is in support of the Waste Forms campaign, Volatile Radionuclide task. Specifically, materials are being developed for the removal and immobilization of iodine and krypton, specifically 129I and 85Kr. During FY 2010, aerogel materials were investigated for removal and immobilization of 129I. Two aerogel formulations were investigated, one based on silica aerogels and the second on chalcogenides. For 85Kr, metal organic framework (MOF) structures were investigated.

  17. An Improved Approach for Analyzing the Oxygen Compatibility of Solvents and other Oxygen-Flammable Materials for Use in Oxygen Systems

    Science.gov (United States)

    Harper, Susan A.; Juarez, Alfredo; Peralta, Stephen F.; Stoltzfus, Joel; Arpin, Christina Pina; Beeson, Harold D.

    2016-01-01

    Solvents used to clean oxygen system components must be assessed for oxygen compatibility, as incompatible residue or fluid inadvertently left behind within an oxygen system can pose a flammability risk. The most recent approach focused on solvent ignition susceptibility to assess the flammability risk associated with these materials. Previous evaluations included Ambient Pressure Liquid Oxygen (LOX) Mechanical Impact Testing (ASTM G86) and Autogenous Ignition Temperature (AIT) Testing (ASTM G72). The goal in this approach was to identify a solvent material that was not flammable in oxygen. As environmental policies restrict the available options of acceptable solvents, it has proven difficult to identify one that is not flammable in oxygen. A more rigorous oxygen compatibility approach is needed in an effort to select a new solvent for NASA applications. NASA White Sands Test Facility proposed an approach that acknowledges oxygen flammability, yet selects solvent materials based on their relative oxygen compatibility ranking, similar to that described in ASTM G63-99. Solvents are selected based on their ranking with respect to minimal ignition susceptibility, damage and propagation potential, as well as their relative ranking when compared with other solvent materials that are successfully used in oxygen systems. Test methods used in this approach included ASTM G86 (Ambient Pressure LOX Mechanical Impact Testing and Pressurized Gaseous Oxygen (GOX) Mechanical Impact Testing), ASTM G72 (AIT Testing), and ASTM D240 (Heat of Combustion (HOC) Testing). Only four solvents were tested through the full battery of tests for evaluation of oxygen compatibility: AK-225G as a baseline comparison, Solstice PF, L-14780, and Vertrel MCA. Baseline solvent AK-225G exhibited the lowest HOC and highest AIT of solvents tested. Nonetheless, Solstice PF, L-14780, and Vertrel MCA HOCs all fell well within the range of properties that are associated with proven oxygen system materials

  18. 49 CFR 571.302 - Standard No. 302; Flammability of interior materials.

    Science.gov (United States)

    2010-10-01

    ... and injuries to motor vehicle occupants caused by vehicle fires, especially those originating in the... compartment covers, mattress covers, and any other interior materials, including padding and crash-deployed elements, that are designed to absorb energy on contact by occupants in the event of a crash. S4.1.1 S4...

  19. Testing Vegetation Flammability: The Problem of Extremely Low Ignition Frequency and Overall Flammability Score

    Directory of Open Access Journals (Sweden)

    Zorica Kauf

    2014-01-01

    Full Text Available In the recent decades changes in fire regimes led to higher vulnerability of fire prone ecosystems, with vegetation being the only component influencing fire regime which can be managed in order to reduce probability of extreme fire events. For these management practices to be effective reliable information on the vegetation flammability is being crucial. Epiradiator based testing methods are one of the methods commonly used to investigate vegetation flammability and decrease in ignition frequency is always interpreted as a decrease in flammability. Furthermore, gathered information is often combined into a single flammability score. Here we present results of leaf litter testing which, together with previously conducted research on similar materials, show that material with very low ignition frequency under certain testing conditions can be extremely flammable if testing conditions are slightly changed. Additionally, our results indicate that combining measured information into one single flammability score, even though sometimes useful, is not always meaningful and should be performed with caution.

  20. [Emission model of volatile organic compounds from materials used indoors].

    Science.gov (United States)

    Han, K

    1998-11-30

    Various materials, such as wall-paper, floor-wax, paint, multicolor wall-coat, air freshener and mothball were experimented in a simulated test chamber under constant selected temperature, humidity and air exchange rate. The relation between the total VOCs concentration and time was regressed by four emission models and the surface emission rate was calculated. The regressed results indicated the similarity among four emission models for the liquid materials with volatile-solvent such as paint and multicolor wall-coat. But for low volatile solid materials, such as wall-paper, floor-wax, mothball, the sink model and the empirical model were better than the dilution model and vapor pressure model. Only for air freshener, it was improper to the total VOCs concentration as a parameter.

  1. Flammability of radiation cross-linked low density polyethylene as an insulating material for wire and cable

    Science.gov (United States)

    Basfar, A. A.

    2002-03-01

    Various formulations of low-density polyethylene blended with ethylene vinyl acetate were prepared to improve the flame retardancy for wire and cable applications. The prepared formulations were cross-linked by γ-rays to 50, 100, 150 and 200 kGy in the presence of trimethylolpropane triacrylate (TMPTA). The effect of thermal aging on mechanical properties of these formulations were investigated. In addition, the influence of various combinations of aluminum trihydroxide and zinc borate as flame retardant fillers on the flammability was explored. Limiting oxygen index (LOI) and average extent of burning were used to characterize the flammability of investigated formulations. An improved flame retardancy of low density polyethylene was achieved by various combinations of flame ratardant fillers and cross-linking by gamma radiation.

  2. The Evaluation of Flammability Properties Regarding Testing Methods

    Directory of Open Access Journals (Sweden)

    Osvaldová Linda Makovická

    2015-12-01

    Full Text Available In this paper, we address the historical comparison methods with current methods for the assessment of flammability characteristics for materials an especially for wood, wood components and wooden buildings. Nowadays in European Union brings harmonization in evaluated of standards into each European country and try to make one concept of evaluated the flammability properties. In each European country to the one standard level which will be used by evaluation of materials regarding flammability. In our article we focused mainly on improving the evaluation methods in terms of flammability characteristics of using materials at building industry. In the article we present examples of different assessment methods at their own test methods in terms of fire prevention. On the base of old compared of materials by STN, BS and DIN methods for testing materials on fire and new methods of evaluating the flammability properties regarding EU standards before and after starting the flash over.

  3. 16 CFR 1500.43 - Method of test for flashpoint of volatile flammable materials by Tagliabue open-cup apparatus.

    Science.gov (United States)

    2010-01-01

    ... Closed Tester, Low Range, Thermometer 57F. For flashpoints below 20 °F., use ASTM Thermometer 33F. The... the “off” position, at one end or the other of the swing, except when the flame is applied. (g) Light... in accordance with the method of test for determination of purity from freezing points of high-purity...

  4. Flammability Assessment Methodology Program Phase I: Final Report

    Energy Technology Data Exchange (ETDEWEB)

    C. A. Loehr; S. M. Djordjevic; K. J. Liekhus; M. J. Connolly

    1997-09-01

    The Flammability Assessment Methodology Program (FAMP) was established to investigate the flammability of gas mixtures found in transuranic (TRU) waste containers. The FAMP results provide a basis for increasing the permissible concentrations of flammable volatile organic compounds (VOCs) in TRU waste containers. The FAMP results will be used to modify the ''Safety Analysis Report for the TRUPACT-II Shipping Package'' (TRUPACT-II SARP) upon acceptance of the methodology by the Nuclear Regulatory Commission. Implementation of the methodology would substantially increase the number of drums that can be shipped to the Waste Isolation Pilot Plant (WIPP) without repackaging or treatment. Central to the program was experimental testing and modeling to predict the gas mixture lower explosive limit (MLEL) of gases observed in TRU waste containers. The experimental data supported selection of an MLEL model that was used in constructing screening limits for flammable VOC and flammable gas concentrations. The MLEL values predicted by the model for individual drums will be utilized to assess flammability for drums that do not meet the screening criteria. Finally, the predicted MLEL values will be used to derive acceptable gas generation rates, decay heat limits, and aspiration time requirements for drums that do not pass the screening limits. The results of the program demonstrate that an increased number of waste containers can be shipped to WIPP within the flammability safety envelope established in the TRUPACT-II SARP.

  5. A Super Cooled, Non-toxic, Non-flammable Phase Change Material Thermal Pack for Portable Life Support Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The concept development and test of a water-based, advanced Phase Change Material (PCM) heat sink is proposed. Utilizing a novel material choice for both an...

  6. A Super Cooled, Non-toxic, Non-flammable Phase Change Material Thermal Pack for Portable Life Support Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The continuation of concept development and test of a water-based, advanced Phase Change Material (PCM) heat sink is proposed. Utilizing a novel material choice for...

  7. Evaluation of Measurement Uncertainty in Determination of Flammability of Automotive Interior Materials%汽车内饰材料燃烧特性的测量不确定度评定

    Institute of Scientific and Technical Information of China (English)

    金月华; 张亚红; 孙霞; 吴谦

    2015-01-01

    Flammability of automotive interior materials was determined according to the standard GB8410-2006. The source of uncertainty in the whole process of measurement was discussed. Each com-ponent of uncertainty was estimated and combined. It was showed that the main factors affecting determi-nation of flammability of automotive interior materials were the repeatability of the test process.%依据GB 8410-2006测量汽车内饰材料的水平燃烧特性,对整个测试过程中的不确定来源进行分析,并对不确定度各个分量进行评定、合成,最后得出影响水平燃烧特性的主要因素是测试过程的重复性。

  8. 汽车内饰材料燃烧特性试验中存在的问题与建议%Problems and Suggestions about Flammability Testing for Automotive Interior Decoration Materials

    Institute of Scientific and Technical Information of China (English)

    史瑞祥; 张凯庆; 陈杰

    2014-01-01

    Through the comparative analysis of domestic and foreign standards about automotive interior decoration materials flammability, the authors find out their disadvantages. Based on the abundant testing data, they summarize the existing problems about the flammability testing for automotive interior decoration materials, and analyze the un-clear description appeared in the testing. Last, they give out corresponding suggestions.%对比分析国内外汽车内饰材料阻燃标准,找出其不足之处。在大量试验基础上,总结国内汽车内饰材料燃烧特性试验中存在的问题,对不明确的地方进行详细地分析研究,并给出相应的建议。

  9. Research on flammability of two typical external insulation materials%两种典型外保温材料燃烧性能研究

    Institute of Scientific and Technical Information of China (English)

    马哲

    2013-01-01

    采用锥形量热仪对岩棉板和挤塑式聚苯乙烯隔热保温板的燃烧性能进行实验研究,实验结果表明,岩棉板的阻燃性能远优于聚苯乙烯隔热保温板,抹面砂浆能够较明显提升聚苯乙烯隔热保温板的阻燃性能,但对岩棉板的阻燃性能影响较小,同时抹面砂浆会增加保温材料烟气及有毒气体释放量.%Experimental study was carried out on the flammability of rock wool board ( RWB) and extruded polystyrene insulation board ( XPSB) by means of Cone Calorimeter. Experimental results show that the flame-retardant properties of the rock wool board are far better than that of polystyrene insulation board. The mortar of surface can obviously enhances the flame-retardant properties of polystyrene insulation board, but it has small effect on the rock wool board. At the same time the mortar will increase the smoke and toxic gases of thermal insulation materials.

  10. Interstage Flammability Analysis Approach

    Science.gov (United States)

    Little, Jeffrey K.; Eppard, William M.

    2011-01-01

    The Interstage of the Ares I launch platform houses several key components which are on standby during First Stage operation: the Reaction Control System (ReCS), the Upper Stage (US) Thrust Vector Control (TVC) and the J-2X with the Main Propulsion System (MPS) propellant feed system. Therefore potentially dangerous leaks of propellants could develop. The Interstage leaks analysis addresses the concerns of localized mixing of hydrogen and oxygen gases to produce deflagration zones in the Interstage of the Ares I launch vehicle during First Stage operation. This report details the approach taken to accomplish the analysis. Specified leakage profiles and actual flammability results are not presented due to proprietary and security restrictions. The interior volume formed by the Interstage walls, bounding interfaces with the Upper and First Stages, and surrounding the J2-X engine was modeled using Loci-CHEM to assess the potential for flammable gas mixtures to develop during First Stage operations. The transient analysis included a derived flammability indicator based on mixture ratios to maintain achievable simulation times. Validation of results was based on a comparison to Interstage pressure profiles outlined in prior NASA studies. The approach proved useful in the bounding of flammability risk in supporting program hazard reviews.

  11. A risk-based approach to flammable gas detector spacing.

    Science.gov (United States)

    Defriend, Stephen; Dejmek, Mark; Porter, Leisa; Deshotels, Bob; Natvig, Bernt

    2008-11-15

    Flammable gas detectors allow an operating company to address leaks before they become serious, by automatically alarming and by initiating isolation and safe venting. Without effective gas detection, there is very limited defense against a flammable gas leak developing into a fire or explosion that could cause loss of life or escalate to cascading failures of nearby vessels, piping, and equipment. While it is commonly recognized that some gas detectors are needed in a process plant containing flammable gas or volatile liquids, there is usually a question of how many are needed. The areas that need protection can be determined by dispersion modeling from potential leak sites. Within the areas that must be protected, the spacing of detectors (or alternatively, number of detectors) should be based on risk. Detector design can be characterized by spacing criteria, which is convenient for design - or alternatively by number of detectors, which is convenient for cost reporting. The factors that influence the risk are site-specific, including process conditions, chemical composition, number of potential leak sites, piping design standards, arrangement of plant equipment and structures, design of isolation and depressurization systems, and frequency of detector testing. Site-specific factors such as those just mentioned affect the size of flammable gas cloud that must be detected (within a specified probability) by the gas detection system. A probability of detection must be specified that gives a design with a tolerable risk of fires and explosions. To determine the optimum spacing of detectors, it is important to consider the probability that a detector will fail at some time and be inoperative until replaced or repaired. A cost-effective approach is based on the combined risk from a representative selection of leakage scenarios, rather than a worst-case evaluation. This means that probability and severity of leak consequences must be evaluated together. In marine and

  12. Preparation, thermal and flammability properties of a novel form-stable phase change materials based on high density polyethylene/poly(ethylene-co-vinyl acetate)/organophilic montmorillonite nanocomposites/paraffin compounds

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Yibing [State Key Laboratory of Fire Science, University of Science and Technology of China, Hefei, Anhui 230027 (China); Key Laboratory of Eco-textiles, Ministry of Education, Jiangnan University, Wuxi, Jiangsu 214122 (China); Song, Lei; He, Qingliang; Yang, Dandan; Hu, Yuan [State Key Laboratory of Fire Science, University of Science and Technology of China, Hefei, Anhui 230027 (China)

    2008-08-15

    The paraffin is one of important thermal energy storage materials with many desirable characteristics (i.e., high heat of fusion, varied phase change temperature, negligible supercooling, self-nucleating, no phase segregation and cheap, etc.), but has low thermal stability and flammable. Hence, a novel form-stable phase change materials (PCM) based on high density polyethylene (HDPE)/poly(ethylene-co-vinyl acetate) (EVA)/organophilic montmorillonite (OMT) nanocomposites and paraffin are prepared by twin-screw extruder technique. The structures of the HDPE-EVA/OMT nanocomposites and the form-stable PCM are evidenced by the X-ray diffraction (XRD), transmission electronic microscopy (TEM) and scanning electronic microscope (SEM). The results of XRD and TEM show that the HDPE-EVA/OMT nanocomposites form the ordered intercalated nanomorphology. The form-stable PCM consists of the paraffin, which acts as a dispersed phase change material and the HDPE-EVA/OMT nanocomposites, which acts as the supporting material. The paraffin disperses in the three-dimensional net structure formed by HDPE-EVA/OMT nanocomposites. The thermal stability, latent heat and flammability properties are characterized by thermogravimetry analysis (TGA), dynamic Fourier-transform infrared (FTIR), differential scanning calorimeter (DSC) and cone calorimeter, respectively. The TGA and dynamic FTIR analyses indicate that the incorporation of suitable amount of OMT into the form-stable PCM increase the thermal stability. The DSC results show that the latent heat of the form-stable PCM has a certain degree decrease. The cone calorimeter shows that the heat release rate (HRR) has remarkably decreases with loading of OMT in the form-stable PCM, contributing to the improved flammability properties. (author)

  13. Preparation, thermal and flammability properties of a novel form-stable phase change materials based on high density polyethylene/poly(ethylene-co-vinyl acetate)/organophilic montmorillonite nanocomposites/paraffin compounds

    Energy Technology Data Exchange (ETDEWEB)

    Cai Yibing [State Key Laboratory of Fire Science, University of Science and Technology of China, Hefei, Anhui 230027 (China); Key Laboratory of Eco-textiles, Ministry of Education, Jiangnan University, Wuxi, Jiangsu 214122 (China); Song Lei [State Key Laboratory of Fire Science, University of Science and Technology of China, Hefei, Anhui 230027 (China)], E-mail: leisong@ustc.edu.cn; He Qingliang; Yang Dandan; Hu Yuan [State Key Laboratory of Fire Science, University of Science and Technology of China, Hefei, Anhui 230027 (China)

    2008-08-15

    The paraffin is one of important thermal energy storage materials with many desirable characteristics (i.e., high heat of fusion, varied phase change temperature, negligible supercooling, self-nucleating, no phase segregation and cheap, etc.), but has low thermal stability and flammable. Hence, a novel form-stable phase change materials (PCM) based on high density polyethylene (HDPE)/poly(ethylene-co-vinyl acetate) (EVA)/organophilic montmorillonite (OMT) nanocomposites and paraffin are prepared by twin-screw extruder technique. The structures of the HDPE-EVA/OMT nanocomposites and the form-stable PCM are evidenced by the X-ray diffraction (XRD), transmission electronic microscopy (TEM) and scanning electronic microscope (SEM). The results of XRD and TEM show that the HDPE-EVA/OMT nanocomposites form the ordered intercalated nanomorphology. The form-stable PCM consists of the paraffin, which acts as a dispersed phase change material and the HDPE-EVA/OMT nanocomposites, which acts as the supporting material. The paraffin disperses in the three-dimensional net structure formed by HDPE-EVA/OMT nanocomposites. The thermal stability, latent heat and flammability properties are characterized by thermogravimetry analysis (TGA), dynamic Fourier-transform infrared (FTIR), differential scanning calorimeter (DSC) and cone calorimeter, respectively. The TGA and dynamic FTIR analyses indicate that the incorporation of suitable amount of OMT into the form-stable PCM increase the thermal stability. The DSC results show that the latent heat of the form-stable PCM has a certain degree decrease. The cone calorimeter shows that the heat release rate (HRR) has remarkably decreases with loading of OMT in the form-stable PCM, contributing to the improved flammability properties.

  14. Model Estimation of Volatilization of Ammonia Applied with Surface Film—Forming Material

    Institute of Scientific and Technical Information of China (English)

    ZHUANGSHUNYAO; YINBIN; 等

    1999-01-01

    Greenhouse experiments were conducted to determine the ammonia volatilization loss with of without application of surface film-forming material (SFFM),Ammonia volatilization loss was estimated by the model developed by Jayaweera and Mikkelsen,The results showed that the model could estimated by the model developed by Jayaweera and Mikkelsen,The results showed that the model could estimate and predict well ammonia volatilization loss also in case of SFFM addition,There was an emended factor B introduced to the model calculation when SFFM was used ,Simulated calculation showed that the effect of factor B on NH3 loss was obvious,The value of B was overned by SFFM and the environtal conditions.Sensitivity analysis suggested that pH was the main factor contronlling NH3 volatilization loss from the floodwater.

  15. A mass transfer model for predicting emission of the volatile organic compounds in wet building materials

    Institute of Scientific and Technical Information of China (English)

    ZHANG Tao; JIA Li

    2008-01-01

    A new mass transfer model is developped to predict the volatile organic compounds (VOCs) from fresh wet building materials. The dry section of wet materials during the process of VOC emission from wet building materials is considered in this new model, differing from the mass transfer-based models in other literatures. The mechanism of effect of saturated vapor pressure on the surface of wet building materials in the process of VOC emission is discussed. The concentration of total volatile organic compounds (TVOC) in the building materials gradually decreases as the emission of VOCs begins, and the vapor pressure of VOCs on the surface of wet building materials decreases in the case of newly wet building materials. To ensure the partial pressure of VOCs on the surface of wet building materials to be saturated vapor pressure, the interface of gas-wet layer is lowered, and a dry layer of no-volatile gases in the material is formed. Compared with the results obtained by VB model, CFD model and the ex-periment data, the results obtained by the present model agree well with the results obtained by CFD model and the experiment data. The present model is more accurate in predicting emission of VOC from wet building materials than VB model.

  16. Methodology for flammable gas evaluations

    Energy Technology Data Exchange (ETDEWEB)

    Hopkins, J.D., Westinghouse Hanford

    1996-06-12

    There are 177 radioactive waste storage tanks at the Hanford Site. The waste generates flammable gases. The waste releases gas continuously, but in some tanks the waste has shown a tendency to trap these flammable gases. When enough gas is trapped in a tank`s waste matrix, it may be released in a way that renders part or all of the tank atmosphere flammable for a period of time. Tanks must be evaluated against previously defined criteria to determine whether they can present a flammable gas hazard. This document presents the methodology for evaluating tanks in two areas of concern in the tank headspace:steady-state flammable-gas concentration resulting from continuous release, and concentration resulting from an episodic gas release.

  17. 简析火灾状态下建筑物内易燃易爆物自动阻断系统%Automatic Blocking System of Flammable and Explosive Materials in Building under the State of Fire

    Institute of Scientific and Technical Information of China (English)

    高影

    2013-01-01

      火灾每年要夺走成千上万人的生命和健康,造成数以亿计的经济损失,存在有易燃易爆物的建筑物在发生火灾的情况下,由于易燃易爆物的燃烧和爆炸,造成火势的加剧,将严重影响消防人员对火势的控制。本文针对以上问题,通过设计控制电路,提出建筑物内易燃易爆物遇到火灾时自动阻断方法。%Fires claimed the lives and health of tens of thousands of people each year, and caused billions of economic losses. In the case of fire, for buildings with flammable and explosive materials, due to the fire and explosion of flammable and explosive materials, the fire will be more intensifies, will be seriously affected fire control. This paper focuses on these issues, through the design of control circuit, proposed the automatic blocking method of inflammable and explosive materials.

  18. Effects of bedding material on ammonia volatilization in a broiler house

    Science.gov (United States)

    Ammonia volatilization from poultry house bedding material is a major production issues because the buildup of ammonia within the facilities is a human health issue and can negatively impact the performance of the birds. Major operational cost is associated with the ventilation of poultry houses to ...

  19. Volatility of propoxur from different surface materials commonly found in homes.

    Science.gov (United States)

    Kuo, H W; Lee, H M

    1999-05-01

    The purpose of this study was to determine the volatilization rates of propoxur from different surface materials commonly found in homes, and to conduct field measurements under ventilated and non-ventilated conditions. Since it is known that temperature, humidity and constant air flow most significantly affect volatility, various surface materials were sprayed using a constant amount of propoxur under the controlled conditions of an exposure chamber. Acetonitrile was used to desorb both XAD-2 resin that collected airborne propoxur and surface materials containing propoxur residue. HPLC was used to analyze propoxur concentrations. Based on multiple regression models, temperature most significantly affected volatility, followed by humidity. Volatilization rates of propoxur were highest from quartz surfaces and lowest from glass. Interaction was most readily found on glass surfaces based on humidity-air flow and humidity-temperature factors. In field applications, propoxur was sprayed in a room under two conditions with ventilation and without in order to measure the concentrations of propoxur in the air and on a quartz surface. Findings showed both airborne and settled concentrations peaked after a half hour then decreased under both conditions, both more sharply in the ventilated room. Under both conditions, no propoxur was detected on the quartz surface after three and a half hours but airborne concentrations remained detectable after thirty-three and one half hours. We conclude that to maintain good air quality, ventilation is important and special care must be taken when spraying insecticides on different surfaces.

  20. Flammable gas project topical report

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, G.D.

    1997-01-29

    The flammable gas safety issue was recognized in 1990 with the declaration of an unreviewed safety question (USQ) by the U. S. Department of Energy as a result of the behavior of the Hanford Site high-level waste tank 241-SY-101. This tank exhibited episodic releases of flammable gas that on a couple of occasions exceeded the lower flammability limit of hydrogen in air. Over the past six years there has been a considerable amount of knowledge gained about the chemical and physical processes that govern the behavior of tank 241-SY-1 01 and other tanks associated with the flammable gas safety issue. This report was prepared to provide an overview of that knowledge and to provide a description of the key information still needed to resolve the issue. Items covered by this report include summaries of the understanding of gas generation, retention and release mechanisms, the composition and flammability behavior of the gas mixture, the amounts of stored gas, and estimated gas release fractions for spontaneous releases. `Me report also discusses methods being developed for evaluating the 177 tanks at the Hanford Site and the problems associated with these methods. Means for measuring the gases emitted from the waste are described along with laboratory experiments designed to gain more information regarding rates of generation, species of gases emitted and modes of gas storage and release. Finally, the process for closing the USQ is outlined as are the information requirements to understand and resolve the flammable gas issue.

  1. Effect of Boric Acid on Volatile Products of Thermooxidative Degradation of Epoxy Polymers

    Science.gov (United States)

    Nazarenko, O. B.; Bukhareva, P. B.; Melnikova, T. V.; Visakh, P. M.

    2016-01-01

    The polymeric materials are characterized by high flammability. The use of flame retardants in order to reduce the flammability of polymers can lead to the formation of toxic gaseous products under fire conditions. In this work we studied the effect of boric acid on the volatile products of thermooxidative degradation of epoxy polymers. The comparative investigations were carried out on the samples of the unfilled epoxy resin and epoxy resin filled with a boric acid at percentage 10 wt. %. The analysis of the volatile decomposition products and thermal stability of the samples under heating in an oxidizing medium was performed using a thermal mass-spectrometric analysis. It is found that the incorporation of boric acid into the polymer matrix increases the thermal stability of epoxy composites and leads to a reduction in the 2-2.7 times of toxic gaseous products

  2. High temperature volatility and oxidation measurements of titanium and silicon containing ceramic materials

    Science.gov (United States)

    Nguyen, Quynhgiao N.

    Titanium (Ti) containing materials are of high interest to the aerospace industry due to its high temperature capability, strength, and light weight. As with most metals an exterior oxide layer naturally exists in environments that contain oxygen (i.e. air). At high temperatures, water vapor plays a key role in the volatility of materials including oxide surfaces. This study first evaluates several hot-pressed Ti-containing compositions at high temperatures as a function of oxidation resistance. This study will also evaluate cold pressed titanium dioxide (TiO2) powder pellets at a temperature range of 1400°C--1200°C in water containing environments to determine the volatile hydoxyl species using the transpiration method. The water content ranged from 0-76 mole % and the oxygen content range was 0-100 mole % during the 20-250 hour exposure times. Preliminary results indicate that oxygen is not a key contributor at these temperatures and the following reaction is the primary volatile equation at all three temperatures: TiO 2 (s) + H2O (g) = TiO(OH)2 (g).

  3. Flammable Gas Safety Self-Study 52827

    Energy Technology Data Exchange (ETDEWEB)

    Glass, George [Los Alamos National Laboratory

    2016-03-17

    This course, Flammable Gas Safety Self-Study (COURSE 52827), presents an overview of the hazards and controls associated with commonly used, compressed flammable gases at Los Alamos National Laboratory (LANL).

  4. Influence of volatile organic compounds of varnish-and-paint materials on the workers organism on the industrial enterprises

    Directory of Open Access Journals (Sweden)

    Г.І. Архіпова

    2010-02-01

    Full Text Available In article describes the reasons of air contamination in working area of endustrial enterprises, defines main ways of incoming and mechanism of action of volatile organic compounds of paintwork material on the organisms of workers.

  5. Algal growth inhibition test in filled, closed bottles for volatile and sorptive materials

    DEFF Research Database (Denmark)

    Mayer, Philipp; Nyholm, Niels; Verbruggen, Eric M. J.;

    2000-01-01

    Exposure concentrations of many hydrophobic substances are difficult to maintain in algal growth inhibition tests performed in open agitated flasks. This is partly because such compounds tend to volatilize from aqueous solution and partly because of sorption to the algal biomass as well as to the......Exposure concentrations of many hydrophobic substances are difficult to maintain in algal growth inhibition tests performed in open agitated flasks. This is partly because such compounds tend to volatilize from aqueous solution and partly because of sorption to the algal biomass as well...... as to the test container. A simple filled closed bottle test with low algal densities and bicarbonate enrichment is described here as an approach to minimize the loss of test material from solution. The algal medium was enriched with 300 mg NaHCO3/L, the pH was adjusted to 7.0 by addition of HCl...

  6. Antimisting kerosene atomization and flammability

    Science.gov (United States)

    Fleeter, R.; Petersen, R. A.; Toaz, R. D.; Jakub, A.; Sarohia, V.

    1982-01-01

    Various parameters found to affect the flammability of antimisting kerosene (Jet A + polymer additive) are investigated. Digital image processing was integrated into a technique for measurement of fuel spray characteristics. This technique was developed to avoid many of the error sources inherent to other spray assessment techniques and was applied to the study of engine fuel nozzle atomization performance with Jet A and antimisting fuel. Aircraft accident fuel spill and ignition dynamics were modeled in a steady state simulator allowing flammability to be measured as a function of airspeed, fuel flow rate, fuel jet Reynolds number and polymer concentration. The digital imaging technique was employed to measure spray characteristics in this simulation and these results were related to flammability test results. Scaling relationships were investigated through correlation of experimental results with characteristic dimensions spanning more than two orders of magnitude.

  7. Studies of volatiles and organic materials in early terrestrial and present-day outer solar system environments

    Science.gov (United States)

    Sagan, Carl; Thompson, W. Reid; Chyba, Christopher F.; Khare, B. N.

    1991-01-01

    A review and partial summary of projects within several areas of research generally involving the origin, distribution, chemistry, and spectral/dielectric properties of volatiles and organic materials in the outer solar system and early terrestrial environments are presented. The major topics covered include: (1) impact delivery of volatiles and organic compounds to the early terrestrial planets; (2) optical constants measurements; (3) spectral classification, chemical processes, and distribution of materials; and (4) radar properties of ice, hydrocarbons, and organic heteropolymers.

  8. Ozone consumption and volatile byproduct formation from surface reactions with aircraft cabin materials and clothing fabrics

    Science.gov (United States)

    Coleman, Beverly K.; Destaillats, Hugo; Hodgson, Alfred T.; Nazaroff, William W.

    We measured ozone consumption and byproduct formation on materials commonly found in aircraft cabins at flight-relevant conditions. Two series of small-chamber experiments were conducted, with most runs at low relative humidity (10%) and high air-exchange rate (˜20 h -1). New and used cabin materials (seat fabric, carpet, and plastic) and laundered and worn clothing fabrics (cotton, polyester, and wool) were studied. We measured ozone deposition to many material samples, and we measured ozone uptake and primary and secondary emissions of volatile organic compounds (VOCs) from a subset of samples. Deposition velocities ranged from 0.06 to 0.54 cm s -1. Emissions of VOCs were higher with ozone than without ozone in every case. The most commonly detected secondary emissions were C 1 through C 10 saturated aldehydes and the squalene oxidation products 6-methyl-5-hepten-2-one and acetone. For the compounds measured, summed VOC emission rates in the presence of 55-128 ppb (residual level) ozone ranged from 1.0 to 8.9 μmol h -1 m -2. Total byproduct yield ranged from 0.07 to 0.24 moles of product volatilized per mole of ozone consumed. Results were used to estimate the relative contribution of different materials to ozone deposition and byproduct emissions in a typical aircraft cabin. The dominant contributor to both was clothing fabrics, followed by seat fabric. Results indicate that ozone reactions with surfaces substantially reduce the ozone concentration in the cabin but also generate volatile byproducts of potential concern for the health and comfort of passengers and crew.

  9. Determination of fine particulate semi-volatile organic material at three eastern U.S. sampling sites.

    Science.gov (United States)

    Warner, K S; Eatough, D J; Stockburger, L

    2001-09-01

    Correct assessment of fine particulate carbonaceous material as a function of particle size is, in part, dependent on the determination of semi-volatile compounds, which can be lost from particles during sampling. This study gives results obtained for the collection of fine particulate carbonaceous material at three eastern U.S. sampling sites [Philadelphia, PA; Shenandoah National Park, VA; and Research Triangle Park (RTP), NC] using diffusion denuder technology. The diffusion denuder samplers allow for the determination of fine particulate organic material with no artifacts, due to the loss of semi-volatile organic particulate compounds, or collection of gas-phase organic compounds by the quartz filter during sampling. The results show that an average of 41, 43, and 59% of fine particulate organic material was lost as volatilized semi-volatile organic material during collection of particles on a filter at Philadelphia, RTP, and Shenandoah, respectively. The particle size distribution of carbonaceous material retained by a filter and lost from a filter during sampling was obtained for the samples collected at Philadelphia and Shenandoah. The carbonaceous material retained by the particles during sampling was found predominantly in particles smaller than 0.4 microm in aerodynamic diameter. In contrast, the semi-volatile organic material lost from the particles during sampling had a mass median diameter of approximately 0.5 microm.

  10. Volatile tritiated organic acids in stack effluents and in air surrounding contaminated materials

    Energy Technology Data Exchange (ETDEWEB)

    Belot, Y.; Camus, H.; Marini, T.; Raviart, S. (Institut de Protection et de Surete Nucleaire (France))

    1993-06-01

    A small fraction of the tritium released into the atmosphere from tritium-handling or solid waste storage facilities was shown to be in the form of volatile organic acids. The same compounds were also found, but at a much higher proportion, in the tritium evolved at room temperature from highly contaminated materials placed under air atmospheres. This might be due to the oxidation and labeling of hydrocarbon(s) by mechanisms that are presumably of a radiolytic nature. The new forms could have an impact on operational requirements and waste management strategies within a tritium facility and a fusion reactor hall. Further data are needed to assess the related doses.

  11. Dark material on Vesta from the infall of carbonaceous volatile-rich material.

    Science.gov (United States)

    McCord, T B; Li, J-Y; Combe, J-P; McSween, H Y; Jaumann, R; Reddy, V; Tosi, F; Williams, D A; Blewett, D T; Turrini, D; Palomba, E; Pieters, C M; De Sanctis, M C; Ammannito, E; Capria, M T; Le Corre, L; Longobardo, A; Nathues, A; Mittlefehldt, D W; Schröder, S E; Hiesinger, H; Beck, A W; Capaccioni, F; Carsenty, U; Keller, H U; Denevi, B W; Sunshine, J M; Raymond, C A; Russell, C T

    2012-11-01

    Localized dark and bright materials, often with extremely different albedos, were recently found on Vesta's surface. The range of albedos is among the largest observed on Solar System rocky bodies. These dark materials, often associated with craters, appear in ejecta and crater walls, and their pyroxene absorption strengths are correlated with material brightness. It was tentatively suggested that the dark material on Vesta could be either exogenic, from carbon-rich, low-velocity impactors, or endogenic, from freshly exposed mafic material or impact melt, created or exposed by impacts. Here we report Vesta spectra and images and use them to derive and interpret the properties of the 'pure' dark and bright materials. We argue that the dark material is mainly from infall of hydrated carbonaceous material (like that found in a major class of meteorites and some comet surfaces), whereas the bright material is the uncontaminated indigenous Vesta basaltic soil. Dark material from low-albedo impactors is diffused over time through the Vestan regolith by impact mixing, creating broader, diffuse darker regions and finally Vesta's background surface material. This is consistent with howardite-eucrite-diogenite meteorites coming from Vesta.

  12. 微重力下固体材料燃烧特性的地面实验模拟方法研究%A Ground-based Experimental Method for Solid Material Flammability Simulation in Microgravity Environment

    Institute of Scientific and Technical Information of China (English)

    王双峰; 肖原

    2012-01-01

    The flame spread characteristics over thermally thin solid materials and the flammability limits of such materials have been investigated in horizontal narrow channels by experimental measurements and numerical simulations. The mechanism of narrow channel device to produce a microgravity environment is discussed. For the low forced flow velocities typically expected in space facilities, flame spread characteristics in microgravity can be effectively reproduced in narrow channels with height of 10~14 mm. Moreover, the measured flammability data in the narrow channels are close to those obtained in microgravity environment. The maximum buoyant velocity is estimated to be about 5 cm/s in the narrow channels. Compared with typical normal gravity test channel with relatively large height, buoyant effect is essentially suppressed. Consequently, a simulated microgravity environment can be produced with the horizontal narrow channels.%在对水平窄通道内典型热薄固体材料的燃烧特性进行实验和数值模拟的基础上,分析了材料表面火焰传播、材料可燃极限与微重力实验结果的相似性,以及窄通道实验模拟微重力材料燃烧特性的机理。研究表明,在航天器舱内常见的低速气流条件下,高度为10mm~14mm的窄通道能较好地模拟微重力环境中材料表面火焰传播的特征,并复现材料的可燃极限曲线;窄通道内火焰诱导的浮力流动速度的最大值约为5cm/s,与常规实验通道(高度较大)相比,窄通道能够有效地限制自然对流,进而提供模拟微重力条件下材料燃烧特性的实验环境。

  13. Flammability as an ecological and evolutionary driver

    Science.gov (United States)

    Pausas, Juli G.; Keeley, Jon E.; Schwilk, Dylan W.

    2017-01-01

    We live on a flammable planet yet there is little consensus on the origin and evolution of flammability in our flora.We argue that part of the problem lies in the concept of flammability, which should not be viewed as a single quantitative trait or metric. Rather, we propose that flammability has three major dimensions that are not necessarily correlated: ignitability, heat release and fire spread rate. These major axes of variation are controlled by different plant traits and have differing ecological impacts during fire.At the individual plant scale, these traits define three flammability strategies observed in fire-prone ecosystems: the non-flammable, the fast-flammable and the hot-flammable strategy (with low ignitability, high flame spread rate and high heat release, respectively). These strategies increase the survival or reproduction under recurrent fires, and thus, plants in fire-prone ecosystems benefit from acquiring one of them; they represent different (alternative) ways to live under recurrent fires.Synthesis. This novel framework based on different flammability strategies helps us to understand variability in flammability across scales, and provides a basis for further research.

  14. Volatile Organic Compound (VOC) emissions from feedlot pen surface materials as affected by within pen location, moisture, and temperature

    Science.gov (United States)

    A laboratory study was conducted to evaluate the effects of pen location, moisture, and temperature on emissions of volatile organic compounds (VOC) from surface materials obtained from feedlot pens where beef cattle were fed a diet containing 30% wet distillers grain plus solubles. Surface material...

  15. Specimen Holder For Flammability Tests

    Science.gov (United States)

    Rucker, Michelle A.

    1992-01-01

    Fixture holds sheet specimens for flammability tests. Frame and clamps designed to minimize local overstress on specimen. Heat capacity of fixture low, interfering less with interpretation of results of test by drawing less heat away from specimen. Accepts films, fabrics, foams, and other sheets, rigid or flexible. Specimens thin or thick, or of variable thickness. Bent to accommodate curved rigid specimens. Also used for such other tests as particle-impact tests.

  16. Emissions of volatile organic compounds from building materials and consumer products

    Science.gov (United States)

    Wallace, Lance A.; Pellizzari, Edo; Leaderer, Brian; Zelon, Harvey; Sheldon, Linda

    EPA's TEAM Study of personal exposure to volatile organic compounds (VOC) in air and drinking water of 650 residents of seven U.S. cities resulted in the identification of a number of possible sources encountered in peoples' normal daily activities and in their homes. A follow-up EPA study of publicaccess buildings implicated other potential sources of exposure. To learn more about these potential sources, 15 building materials and common consumer products were analyzed using a headspace technique to detect organic emissions and to compare relative amounts. About 10-100 organic compounds were detected offgassing from each material. Four mixtures of materials were then chosen for detailed study: paint on sheetrock; carpet and carpet glue; wallpaper and adhesives; cleansers and a spray pesticide. The materials were applied as normally used, allowed to age 1 week (except for the cleansers and pesticides, which were used normally during the monitoring period), and placed in an environmentally controlled chamber. Organic vapors were collected on Tenax-GC over a 4-h period and analyzed by GC-MS techniques. Emission rates and chamber concentrations were calculated for 17 target chemicals chosen for their toxic, carcinogenic or mutagenic properties. Thirteen of the 17 chemicals were emitted by one or more of the materials. Elevated concentrations of chloroform, carbon tetrachloride, 1,1,1-trichloroethane, n-decane, n-undecane, p-dichlorobenzene, 1,2-dichloroethane and styrene were produced by the four mixtures of materials tested. For some chemicals, these amounts were sufficient to account for a significant fraction of the elevated concentrations observed in previous indoor air studies. We conclude that common materials found in nearly every home and place of business may cause elevated exposures to toxic chemicals.

  17. Carbon dioxide dilution effect on flammability limits for hydrocarbons.

    Science.gov (United States)

    Chen, Chan-Cheng; Liaw, Horng-Jang; Wang, Tzu-Chi; Lin, Chin-Yu

    2009-04-30

    Theoretical models to predict the upper/lower flammability limits of a mixture composed of hydrocarbon and inert carbon dioxide are proposed in this study. It is found theoretically that there are linear relations between the reciprocal of the upper/lower flammability limits and the reciprocal of the molar fraction of hydrocarbon in the hydrocarbon/inert gas mixture. These theoretical linear relations are examined by existing experimental results reported in the literature, which include the cases of methane, propane, ethylene, and propylene. The coefficients of determination (R(2)) of the regression lines are found to be larger than 0.959 for all aforementioned cases. Thus, the proposed models are highly supported by existing experimental results. A preliminary study also shows the conclusions in present work have the possibility to extend to non-hydrocarbon flammable materials or to inert gas other than carbon dioxide. It is coincident that the theoretical model for the lower flammability limit (LFL) in present work is the same as the empirical model conjectured by Kondo et al.

  18. Fundamental mass transfer modeling of emission of volatile organic compounds from building materials

    Science.gov (United States)

    Bodalal, Awad Saad

    In this study, a mass transfer theory based model is presented for characterizing the VOC emissions from building materials. A 3-D diffusion model is developed to describe the emissions of volatile organic compounds (VOCs) from individual sources. Then the formulation is extended to include the emissions from composite sources (system comprising an assemblage of individual sources). The key parameters for the model (The diffusion coefficient of the VOC in the source material D, and the equilibrium partition coefficient k e) were determined independently (model parameters are determined without the use of chamber emission data). This procedure eliminated to a large extent the need for emission testing using environmental chambers, which is costly, time consuming, and may be subject to confounding sink effects. An experimental method is developed and implemented to measure directly the internal diffusion (D) and partition coefficients ( ke). The use of the method is illustrated for three types of VOC's: (i) Aliphatic Hydrocarbons, (ii) Aromatic Hydrocarbons and ( iii) Aldehydes, through typical dry building materials (carpet, plywood, particleboard, vinyl floor tile, gypsum board, sub-floor tile and OSB). Then correlations for predicting D and ke based solely on commonly available properties such as molecular weight and vapour pressure were proposed for each product and type of VOC. These correlations can be used to estimate the D and ke when direct measurement data are not available, and thus facilitate the prediction of VOC emissions from the building materials using mass transfer theory. The VOC emissions from a sub-floor material (made of the recycled automobile tires), and a particleboard are measured and predicted. Finally, a mathematical model to predict the diffusion coefficient through complex sources (floor adhesive) as a function of time was developed. Then this model (for diffusion coefficient in complex sources) was used to predict the emission rate from

  19. Operational Considerations for Oxygen Flammability Risks: Concentrated Oxygen Diffusion and Permeation Behaviors

    Science.gov (United States)

    Harper, Susana; Smith, Sarah; Juarez, Alfredo; Hirsch, David

    2010-01-01

    Increased human spaceflight operations utilize oxygen concentrations that are frequently varied with use of concentrations up to 100 percent oxygen. Even after exiting a higher percentage oxygen environment, high oxygen concentrations can still be maintained due to material saturation and oxygen entrapment between barrier materials. This paper examines the material flammability concerns that arise from changing oxygen environments during spaceflight operations. We examine the time required for common spacecraft and spacesuit materials exposed to oxygen to return to reduced ignitability and flammability once removed from the increased concentration. Various common spacecraft materials were considered: spacecraft cabin environment foams, Extra Vehicular Mobility Unit materials and foams, Advanced Crew Escape Suit materials, and other materials of interest such as Cotton, Nomex^ HT90-40, and Tiburon Surgical Drape. This paper presents calculated diffusion coefficients derived from experimentally obtained oxygen transmission rates for the tested materials and the analytically derived times necessary for reduced flammability to be achieved based on NASA flammability criteria. Oxygen material saturation and entrapment scenarios are examined. Experimental verification data on oxygen diffusion in saturation scenarios are also presented and discussed. We examine how to use obtained data to address flammability concerns during operational planning to reduce the likelihood of fires while improving efficiency for procedures.

  20. Nitrogen dilution effect on the flammability limits for hydrocarbons.

    Science.gov (United States)

    Chen, Chan-Cheng; Wang, Tzu-Chi; Liaw, Horng-Jang; Chen, Hui-Chu

    2009-07-30

    Theoretical models to predict the upper/lower flammability limits of hydrocarbons diluted with inert nitrogen gas are proposed in this study. It is found that there are linear relations between the reciprocal of the upper/lower flammability limits and the reciprocal of the molar fraction of hydrocarbon in the hydrocarbon/inert nitrogen mixture. Such linearity is examined by experimental data reported in the literature, which include the cases of methane, propane, ethylene and propylene. The R-squared values (R(2)) of the regression lines of the cases explored are all greater than 0.989 for upper flammability limit (UFL). The theoretical slope of the predictive line for lower flammability limit (LFL) is found to be very close to zero for all explored cases; and this result successfully explains the experimental fact that adding inert nitrogen to a flammable material has very limited effect on LFL. Because limit oxygen concentration (LOC) could be taken as the intersectional point of the UFL curve and LFL curve, a LOC-based method is proposed to predict the slope of the UFL curve when experimental data of UFL are not available. This LOC-based method predicts the UFL with average error ranging from 2.17% to 5.84% and maximum error ranging from 8.58% to 12.18% for the cases explored. The predictive models for inert gas of nitrogen are also extended to the case of inert gas other than nitrogen. Through the extended models, it was found that the inert ability of an inert gas depends on its mean molar heat capacity at the adiabatic flame temperature. Theoretical calculation shows that the inert abilities of carbon dioxide, steam, nitrogen and helium are in the following order: carbon dioxide>steam>nitrogen>helium; and this sequence conforms to the existing experimental data reported in the literature.

  1. Plant traits determine forest flammability

    Science.gov (United States)

    Zylstra, Philip; Bradstock, Ross

    2016-04-01

    Carbon and nutrient cycles in forest ecosystems are influenced by their inherent flammability - a property determined by the traits of the component plant species that form the fuel and influence the micro climate of a fire. In the absence of a model capable of explaining the complexity of such a system however, flammability is frequently represented by simple metrics such as surface fuel load. The implications of modelling fire - flammability feedbacks using surface fuel load were examined and compared to a biophysical, mechanistic model (Forest Flammability Model) that incorporates the influence of structural plant traits (e.g. crown shape and spacing) and leaf traits (e.g. thickness, dimensions and moisture). Fuels burn with values of combustibility modelled from leaf traits, transferring convective heat along vectors defined by flame angle and with plume temperatures that decrease with distance from the flame. Flames are re-calculated in one-second time-steps, with new leaves within the plant, neighbouring plants or higher strata ignited when the modelled time to ignition is reached, and other leaves extinguishing when their modelled flame duration is exceeded. The relative influence of surface fuels, vegetation structure and plant leaf traits were examined by comparing flame heights modelled using three treatments that successively added these components within the FFM. Validation was performed across a diverse range of eucalypt forests burnt under widely varying conditions during a forest fire in the Brindabella Ranges west of Canberra (ACT) in 2003. Flame heights ranged from 10 cm to more than 20 m, with an average of 4 m. When modelled from surface fuels alone, flame heights were on average 1.5m smaller than observed values, and were predicted within the error range 28% of the time. The addition of plant structure produced predicted flame heights that were on average 1.5m larger than observed, but were correct 53% of the time. The over-prediction in this

  2. Chlorine and Sulfur Volatiles from in Situ Measurements of Martian Surface Materials

    Science.gov (United States)

    Clark, B. C.

    2014-12-01

    A sentinel discovery by the first in situ measurements on Mars was the high sulfur and chlorine content of global-wide soils. A variety of circumstantial evidence led to the conclusion that soil S is in the form of sulfate, and the Cl is probably chloride. An early hypothesis states that these volatiles are emitted as gases from magmas, and quickly react with dust, soil, and exposed rocks. Subsequent determination that SNC meteorites are also samples of the martian crust revealed a significantly higher S content, as sulfide, than terrestrial igneous rocks but substantially less than in soils. The ensuing wet chemical analyses by the high-latitude Phoenix mission discovered not only chloride but also perchlorate and possibly chlorate. MSL data now also implicate perchlorate at low latitudes. Gaseous interactions may have produced amorphous material on grain surfaces without forming stoichiometric salts. Yet, when exposed to liquid water, Phoenix samples released electrolytes, indicating that the soils have not been leached by rain or fresh groundwater. Sulfate occurrences at many locations on Mars, as well as some chloride enrichments, have now been discovered by remote sensing, Landed missions have discovered Cl-enrichments and ferric, Mg, Ca and more complex sulfates as duricrust, subsurface soil horizons, sandstone evaporites, and rock coatings - most of which cannot be detected from orbit. Salt-forming volatiles affect habitability wherever they are in physical contact: physicochemical parameters (ionic strength, freezing point, water activity); S is an essential element for terrestrial organisms; perchlorate is an oxidant which can degrade some organics but also can be utilized as an energy source; the entire valence range of S-compounds has been exploited by diverse microbiota on Earth. Whether such salt-induced conditions are "extremes" of habitability depends on the relative abundance of liquid H2O.

  3. A modified method for evaluation of materials containing volatile corrosion inhibitor

    Institute of Scientific and Technical Information of China (English)

    WAN Hong-jing; HUANG Hong-jun; ZHANG Min; LI Zhi-guang

    2005-01-01

    A systematic research on a modified method that was developed to evaluate the effectiveness of volatile corrosion inhibitor(VCI) materials was carried out. The metal specimen in size of 50 mm×25 mm×2 mm was level mounted on the top of a beaker by transparent adhesive tape and the assembly was placed in a constant temperature water bath and kept at approximately 40 ℃ to accelerate the vaporization of VCI and distilled water, which was placed at the bottom of the beaker at the same time. The experimental results show that the reproducibility of rust appearance and corrosion rate calculated by specimen's mass loss is perfect. The outstanding characteristic of the rust appearance based on different VCI formula is discovered that is very important in studying the mechanism of VCI and the synergism of chemical reagent. The accelerated ratio is increased greatly as compared with the traditional method and the value is approximately 15 as compared with Shijiazhuang atmospheric environment corrosion test. The modified method is suitable for formula screening test and quick effectiveness evaluation of VCI materials.

  4. Sparse graphs are not flammable

    CERN Document Server

    Prałat, Paweł

    2012-01-01

    In this paper, we consider the following \\emph{$k$-many firefighter problem} on a finite graph $G=(V,E)$. Suppose that a fire breaks out at a given vertex $v \\in V$. In each subsequent time unit, a firefighter protects $k$ vertices which are not yet on fire, and then the fire spreads to all unprotected neighbours of the vertices on fire. The objective of the firefighter is to save as many vertices as possible. The surviving rate $\\rho(G)$ of $G$ is defined as the expected percentage of vertices that can be saved when a fire breaks out at a random vertex of $G$. Let $\\tau_k = k+2-\\frac {1}{k+2}$. We show that for any $\\eps >0$ and $k \\ge 2$, each graph $G$ on $n$ vertices with at most $(\\tau_k-\\eps)n$ edges is not flammable; that is, $\\rho(G) > \\frac {2\\eps}{5\\tau_k} > 0$. Moreover, a construction of a family of flammable random graphs is proposed to show that the constant $\\tau_k$ cannot be improved.

  5. Volatile organic chemical emissions from structural insulated panel (SIP) materials and implications for indoor air quality

    Energy Technology Data Exchange (ETDEWEB)

    Hodgson, Alfred T.

    2003-09-01

    The emissions of volatile organic compounds (VOCs) from structural insulated panel (SIP) materials were investigated. Specimens of newly produced SIPs and associated panel adhesives were obtained from two relatively large manufacturers. Additionally, specimens of the oriented strand board (OSB) used as the inner and outer sheathing and the extruded polystyrene core for the SIP were obtained from one manufacturer. Using small-scale chambers, emissions of formaldehyde, acetaldehyde, acetic acid and other VOCs from SIPs, OSB and polystyrene were measured over a period of four months and from the adhesives over two months. SIP specimens overlaid by gypsum board panels were also tested over four months. The predominant VOCs emitted by the SIPs included acetic acid, pentanal, hexanal and styrene. The emissions of formaldehyde and acetaldehyde were relatively low. Acetic acid and the aldehydes derived from the OSB, while styrene derived from the polystyrene. One of the SIPs emitted toluene and methyl acetate. The adhesives primarily emitted a mixture of hydrocarbons. The emission rates of most VOCs from the SIP/gypsum board assemblies were approximately the same or higher than their respective emission rates from the unfinished SIPs. Modeling using VOC emission factors obtained for the SIP/gypsum board assemblies demonstrated the potential for SIP materials to degrade indoor air quality in houses. A field study to investigate VOC concentrations and emission rates in SIP houses relative to closely matched conventionally constructed houses is necessary to determine the actual impacts of SIPs. If significant impacts are observed, to it may be desirable to develop control measures to reduce the emissions of VOCs from SIPs, such as the substitution of lower emitting materials or the use of vapor diffusion barriers.

  6. Volatile Retention and Morphological Properties of Microencapsulated Tributyrin Varied by Wall Material and Drying Method.

    Science.gov (United States)

    Donovan, Joseph D; Cadwallader, Keith R; Lee, Youngsoo

    2016-03-01

    Butyric acid is an important short-chain fatty acid for intestinal health and has been shown to improve certain intestinal disease states. A triglyceride containing 3 butyric acid esters, tributyrin (TB) can serve as a source of butyric acid; however, the need to target intestinal delivery and mitigate unpleasant sensory qualities has limited its use in food. Microencapsulation, the entrapment of one or more cores within a matrix, may provide a solution to the aforementioned challenge. This research primarily focused on the influence of (1) wall material: whey and soy protein isolate (WPI and SPI, respectively) and gamma-cyclodextrin (GCD), (2) wall additives: inulin of varying chain length, and (3) processing method: spray or oven drying (SD or OD, respectively) on the morphological properties and volatile retention of TB within microcapsules. SPI-based microcapsules retained significantly less (P spray dried, the GCD-based microcapsules exhibited (P spray drying. These findings demonstrate that microencapsulated TB in GCD can lead to minimal TB losses during processing that could be utilized in functional food applications for intestinal health.

  7. Gas chromatography of volatile fatty acids. Method involving separation from biological material by vacuum distillation.

    Science.gov (United States)

    Tyler, J E; Dibdin, G H

    1975-02-19

    A method is described for the quantitation of C2-C5 volatile fatty acids present in biological tissues. It involved recovery of the acids from their biological matrix by vacuum micro-distillation at room temperature, followed by gas phase separation of aqueous solutions on orthophosphoric acid-modified Phasepak Q columns. The subsequent gas chromatographic procedure resolved iso from normal isomers and showed a linear response for each volatile acid over the range 10-400 ng. There was no evidence of ghosting, isomer peak broadening, or peak tailing. Relative molar response values were shown to be linear with carbon number for all the volatile fatty acids studied.

  8. Comparison of two common adsorption materials for thermal desorption gas chromatography - mass spectrometry of biogenic volatile organic compounds.

    Science.gov (United States)

    Marcillo, Andrea; Jakimovska, Viktorija; Widdig, Anja; Birkemeyer, Claudia

    2017-09-08

    Volatile organic compounds (VOCs) are commonly collected from gaseous samples by adsorption to materials such as the porous polymer Tenax TA. Adsorbed compounds are subsequently released from these materials by thermal desorption (TD) and separated then by gas chromatography (GC) with flame ionization (FID) or mass spectrometry (MS) detection. Tenax TA is known to be particularly suitable for non-polar to semipolar volatiles, however, many volatiles from environmental and biological samples possess a rather polar character. Therefore, we tested if the polymer XAD-2, which so far is widely used to adsorb organic compounds from aqueous and organic solvents, could provide a broader coverage for (semi)polar VOCs during gas-phase sampling. Mixtures of volatile compounds covering a wide range of volatility (bp. 20-256°C) and different chemical classes were introduced by liquid spiking into sorbent tubes with one of the two porous polymers, Tenax TA or XAD-2, and analyzed by TD/GC-MS. At first, an internal standard mixture composed of 17 authentic standards was used to optimize desorption temperature with respect to sorbent degradation and loading time for calibration. Secondly, we tested the detectability of a complex standard mixture composed of 57 volatiles, most of them common constituents of the body odor of mammals. Moreover, the performance of XAD-2 compared with Tenax TA was assessed as limit of quantitation and linearity for the internal standard mixture and 33 compounds from the complex standard mixture. Volatiles were analyzed in a range between 0.01-∼250ng/tube depending on the compound and material. Lower limits of quantitation were between 0.01 and 3 ng±0.9). Interestingly, we found different kinetics for compound adsorption with XAD-2, and a partially better sensitivity in comparison with Tenax TA. For these analytes, XAD-2 might be recommended as an alternative of Tenax TA for TD/GC-MS analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Remarks on Flammability Testing of Aerospace Materials

    Science.gov (United States)

    Hirsch, David B.; Beeson, Harold D.

    2013-01-01

    Agenda for the presentation: (1) Brief background of ISO 16697 (a) Reasons for the approach (b) Stated intent for this International Technical Specification (2) Evolution of initial considerations for the ISO approach (3) Discussion and recommendation

  10. The isotope composition of selenium in chondrites constrains the depletion mechanism of volatile elements in solar system materials

    Science.gov (United States)

    Vollstaedt, Hauke; Mezger, Klaus; Leya, Ingo

    2016-09-01

    Solar nebula processes led to a depletion of volatile elements in different chondrite groups when compared to the bulk chemical composition of the solar system deduced from the Sun's photosphere. For moderately-volatile elements, this depletion primarily correlates with the element condensation temperature and is possibly caused by incomplete condensation from a hot solar nebula, evaporative loss from the precursor dust, and/or inherited from the interstellar medium. Element concentrations and interelement ratios of volatile elements do not provide a clear picture about responsible mechanisms. Here, the abundance and stable isotope composition of the moderately- to highly-volatile element Se are investigated in carbonaceous, ordinary, and enstatite chondrites to constrain the mechanism responsible for the depletion of volatile elements in planetary bodies of the inner solar system and to define a δ 82 / 78 Se value for the bulk solar system. The δ 82 / 78 Se of the studied chondrite falls are identical within their measurement uncertainties with a mean of - 0.20 ± 0.26 ‰ (2 s.d., n = 14, relative to NIST SRM 3149) despite Se abundance depletions of up to a factor of 2.5 with respect to the CI group. The absence of resolvable Se isotope fractionation rules out a kinetic Rayleigh-type incomplete condensation of Se from the hot solar nebula or partial kinetic evaporative loss on the precursor material and/or the parent bodies. The Se depletion, if acquired during partial condensation or evaporative loss, therefore must have occurred under near equilibrium conditions to prevent measurable isotope fractionation. Alternatively, the depletion and cooling of the nebula could have occurred simultaneously due to the continuous removal of gas and fine particles by the solar wind accompanied by the quantitative condensation of elements from the pre-depleted gas. In this scenario the condensation of elements does not require equilibrium conditions to avoid isotope

  11. Sapphire: a better material for atomization and in situ collection of silver volatile species for atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Musil, Stanislav, E-mail: stanomusil@biomed.cas.cz; Matoušek, Tomáš; Dědina, Jiří

    2015-06-01

    Sapphire is presented as a high temperature and corrosion resistant material of an optical tube of an atomizer for volatile species of Ag generated by the reaction with NaBH{sub 4}. The modular atomizer design was employed which allowed to carry out the measurements in two modes: (i) on-line atomization and (ii) in situ collection (directly in the optical tube) by means of excess of O{sub 2} over H{sub 2} in the carrier gas during the trapping step and vice versa in the volatilization step. In comparison with quartz atomizers, the sapphire tube atomizer provides a significantly increased atomizer lifetime as well as substantially improved repeatability of the Ag in situ collection signals shapes. In situ collection of Ag in the sapphire tube atomizer was highly efficient (> 90%). Limit of detection in the on-line atomization mode and in situ collection mode, respectively, was 1.2 ng ml{sup −1} and 0.15 ng ml{sup −1}. - Highlights: • Sapphire was tested as a new material of an atomizer tube for Ag volatile species. • Two measurement modes were investigated: on-line atomization and in situ collection. • In situ collection of Ag was highly efficient (> 90%) with LOD of 0.15 ng ml{sup −1}. • No devitrification of the sapphire tube observed in the course of several months.

  12. STEADY STATE FLAMMABLE GAS RELEASE RATE CALCULATION & LOWER FLAMMABILITY LEVEL EVALUATION FOR HANFORD TANK WASTE

    Energy Technology Data Exchange (ETDEWEB)

    HU, T.A.

    2005-10-27

    Assess the steady-state flammability level at normal and off-normal ventilation conditions. The hydrogen generation rate was calculated for 177 tanks using the rate equation model. Flammability calculations based on hydrogen, ammonia, and methane were performed for 177 tanks for various scenarios.

  13. STEADY STATE FLAMMABLE GAS RELEASE RATE CALCULATION AND LOWER FLAMMABILITY LEVEL EVALUATION FOR HANFORD TANK WASTE

    Energy Technology Data Exchange (ETDEWEB)

    HU TA

    2009-10-26

    Assess the steady-state flammability level at normal and off-normal ventilation conditions. The hydrogen generation rate was calculated for 177 tanks using the rate equation model. Flammability calculations based on hydrogen, ammonia, and methane were performed for 177 tanks for various scenarios.

  14. The Research Summary on the Automatic Blocking System of Flammable and Explosive Materials and Thinking About the Existing Problems%易燃易爆物自动阻断系统的研究总结及存在问题的思考

    Institute of Scientific and Technical Information of China (English)

    李明君; 张晓峰; 温红真; 刘春江

    2015-01-01

    In view of the current separation problem of the flammable and explosive materials, a set of automatic blocking system is designed again, which is placing the flammable and explosive materials in the high temperature resistant boxes, to form the vacuum isolation belt when fire occurs. And use the wireless technology to send fire alarm message. But in designing the system, a lot of problems occur, and the problems are reflected, to provide reference for users and similar systems developers. In this paper, the research summary and the existing problems of the system are reflected.%针对目前易燃易爆物品的隔离问题,重新设计了一套自动阻断系统,将易燃易爆物放置于耐高温箱体中,火灾发生时形成真空隔离带,并利用无线技术发出火灾报警信息.但在系统设计中也发现了很多问题,并对问题进行了反思,以供使用者和类似系统的开发者借鉴.本文就阻断系统的研究结论及存在的问题进行反思.

  15. Methods of Off-Gas Flammability Control for DWPF Melter Off-Gas System at Savannah River Site

    Energy Technology Data Exchange (ETDEWEB)

    Choi, A.S. [Westinghouse Savannah River Company, AIKEN, SC (United States); Iverson, D.C.

    1996-05-02

    Several key operating variables affecting off-gas flammability in a slurry-fed radioactive waste glass melter are discussed, and the methods used to prevent potential off-gas flammability are presented. Two models have played a central role in developing such methods. The first model attempts to describe the chemical events occurring during the calcining and melting steps using a multistage thermodynamic equilibrium approach, and it calculates the compositions of glass and calcine gases. Volatile feed components and calcine gases are fed to the second model which then predicts the process dynamics of the entire melter off-gas system including off-gas flammability under both steady state and various transient operating conditions. Results of recent simulation runs are also compared with available data

  16. Headspace Gas Chromatography Method for Studies of Reaction and Permeation of Volatile Agents with Solid Materials

    Science.gov (United States)

    2015-01-01

    oxidation using potassium iodide solution. 13.2.1. Repeated sampling of the same sample vial: Each vial was remeasured in this experiment. Results for...criteria. 9.1 Routine stability testing The QC sensitivity measurement can be done by preparing a vial with a standard quantity of a reagent... stability checks has been a problem for this method. The problem is illustrated in Figure 1. Volatile compounds like triethylphosphate or

  17. The Efficiency of Non-Flammable Functional Underwear

    Directory of Open Access Journals (Sweden)

    Glombikova Viera

    2014-09-01

    Full Text Available This study evaluates the efficiency of non-flammable functional underwear used as a secondary heat barrier in extreme conditions. Five groups of knitted fabrics were analysed for flame resistance and selected physiological properties (water vapour permeability, air permeability, thermal resistance and liquid moisture transport by moisture management transport. The results indicated similar levels of flame resistance for the materials tested but show important differences in terms of physiological characteristics, namely liquid moisture transport, which influences the safety and comfort of protective clothing.

  18. Flammability of tree species for use in fuelbreaks at forest fires prevention

    Directory of Open Access Journals (Sweden)

    Bruna Kovalsyki

    2017-01-01

    Full Text Available Among several silvicultural measures of forest fires prevention, fuelbreaks stands out. These structures are used to reduce and/or prevent fire spread. They consist of plantations with lower flammability species than the main species. The aim of this study was to evaluate the flammability of Psidium cattleianum Sabine., Ligustrum lucidum W. T. Aiton., Schinus terebinthifolius Raddi. and Bougainvillea glabra Choisy, for potential use in fuelbreaks. In this research Pinus taeda L. was used as control. Samples consisted of 1 g of fine material (< 0.7 cm of diameter newly collected. Samples burning were performed in epiradiator, under temperature between 250 °C and 350 °C. It was carried out 50 replications for each species. It was analyzed ignition frequency, time to ignition, combustion duration, combustion index, and it was also determined flammability value. P. taeda presents a very high combustion intensity and was classified as a flammable species. The other species were considered poorly flammable. S. terebinthifolius and B. glabra indicated low combustion intensity, L. lucidum medium and P. cattleianum high combustion intensity. In this context, it was concluded that these species have potential to be used in fuelbreaks to prevent forest fires.

  19. Flammable gas interlock spoolpiece flow response test plan and procedure

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, T.C., Fluor Daniel Hanford

    1997-02-13

    The purpose of this test plan and procedure is to test the Whittaker electrochemical cell and the Sierra Monitor Corp. flammable gas monitors in a simulated field flow configuration. The sensors are used on the Rotary Mode Core Sampling (RMCS) Flammable Gas Interlock (FGI), to detect flammable gases, including hydrogen and teminate the core sampling activity at a predetermined concentration level.

  20. 16 CFR Figure 2 to Part 1610 - Flammability Apparatus Views

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Flammability Apparatus Views 2 Figure 2 to Part 1610 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FLAMMABLE FABRICS ACT REGULATIONS STANDARD FOR THE FLAMMABILITY OF CLOTHING TEXTILES Pt.1610, Fig. 2 Figure 2 to Part...

  1. 14 CFR 25.1727 - Flammable fluid shutoff means: EWIS.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Flammable fluid shutoff means: EWIS. 25... Systems (EWIS) § 25.1727 Flammable fluid shutoff means: EWIS. EWIS associated with each flammable fluid shutoff means and control must be fireproof or must be located and protected so that any fire in a...

  2. Calibration assessment of forest flammability potential in Italy

    Directory of Open Access Journals (Sweden)

    Corona P

    2014-10-01

    Full Text Available Fuel flammability is defined as the relative ease with which a fuel will ignite and burn with a flame; different forest types have different intrinsic “baseline” flammabilities, depending on the susceptibility to burn of the main tree species that build up the forest cover. In this perspective, we apply a forest-type based approach to classify and map the flammability level of the forests in Italy. Baseline forest type-based flammability values provided at European level have been assigned to a national forest types map, derived from Corine Land Cover 2006; flammability values have been then further calibrated against the Burned Area Selection Ratio, a measure of the actual incidence of wildfires among different forest types. Accordingly, a calibrated flammability index was derived by simple linear regression, so that predicted flammability more accurately reflects observed fire incidence among different forest types in Italy. Findings show that the flammability of forest types ranges from low to high: on average, the 17% of the forest cover has medium to high flammability, with wide regional variability; notably, in four Regions (Sardegna, Sicilia, Puglia, Calabria over one third of total forest area has medium to high flammability. Large scale mapping of forest flammability is crucial to define long-term priorities among forest areas as to how to distribute fire management effort: areas falling into medium to high flammability classes should be given priority for implementing fuel management treatments in order to mitigate fire hazard from the stand to the landscape scale.

  3. An Improved Analytical Approach to Determine the Explosive Effects of Flammable Gas-Air Mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Yang, J M

    2005-11-10

    The U.S. Department of Energy (DOE) Complex includes many sites and laboratories that store quantities of low-level, solid nuclear waste in drums and other types of shipping containers. The drums may be stored for long periods of time prior to being transported and final dispositioning. Based on the radioactivity (e.g., Pu{sup 239} equivalent), chemical nature (e.g. volatile organic compounds) and other characteristics of the stored waste, flammable gases may evolve. Documented safety analyses (DSAs) for storage of these drums must address storage and safety management issues to protect workers, the general public, and the environment. This paper discusses an improved analytical method for determining the explosion effects flammable gas-air mixtures as well as the subsequent accident phenomenology.

  4. STEADY-STATE FLAMMABLE GAS RELEASE RATE CALCULATION AND LOWER FLAMMABILITY LEVEL EVALUATION FOR HANFORD TANK WASTE

    Energy Technology Data Exchange (ETDEWEB)

    HU TA

    2007-10-26

    Assess the steady-state flammability level at normal and off-normal ventilation conditions. The methodology of flammability analysis for Hanford tank waste is developed. The hydrogen generation rate model was applied to calculate the gas generation rate for 177 tanks. Flammability concentrations and the time to reach 25% and 100% of the lower flammability limit, and the minimum ventilation rate to keep from 100 of the LFL are calculated for 177 tanks at various scenarios.

  5. Strong Fluorescent Smart Organogel as a Dual Sensing Material for Volatile Acid and Organic Amine Vapors.

    Science.gov (United States)

    Xue, Pengchong; Yao, Boqi; Wang, Panpan; Gong, Peng; Zhang, Zhenqi; Lu, Ran

    2015-11-23

    An L-phenylalanine derivative (C12PhBPCP) consisting of a strong emission fluorophore with benzoxazole and cyano groups is designed and synthesized to realize dual responses to volatile acid and organic amine vapors. The photophysical properties and self-assembly of the said derivative in the gel phase are also studied. C12PhBPCP can gelate organic solvents and self-assemble into 1 D nanofibers in the gels. UV/Vis absorption spectral results show H-aggregate formation during gelation, which indicates strong exciton coupling between fluorophores. Both wet gel and xerogel emit strong green fluorescence because the cyano group suppresses fluorescence quenching in the self-assemblies. Moreover, the xerogel film with strong green fluorescence can be used as a dual chemosensor for quantitative detection of volatile acid and organic amine vapors with fast response times and low detection limits owing to its large surface area and amplified fluorescence quenching. The detection limits are 796 ppt and 25 ppb for gaseous aniline and trifluoroacetic acid (TFA), respectively.

  6. FLAMMABILITY OF ARALDITE BASED COMPOSITE MIXED WITH INORGANIC RETARDANTS

    Directory of Open Access Journals (Sweden)

    ALI I. AL-MOSAWI

    2012-10-01

    Full Text Available Flammability characteristics of araldite based composite mixed with inorganic hybrid flame retardant represent zinc borate - antimony trioxide as a surface layer(4mm thickness have been studied by thermal erosion test . Antimony trioxide was added to zinc borate with various amounts (10%,20% and 30% to forming a hybrid flame retardant for enhance the action of this material to react flame . The result composite material was exposed to a direct flame generated from Oxyacetylene torch (3000ºC with different flame exposure intervals (10,20mm, and studies the range of resistance of retardant material layer to the flames and protected the substrate. The optimum results were with large percentage from protective layer which is zinc borate-30% antimony trioxide and large exposed distance.

  7. A powerful methodological approach combining headspace solid phase microextraction, mass spectrometry and multivariate analysis for profiling the volatile metabolomic pattern of beer starting raw materials.

    Science.gov (United States)

    Gonçalves, João L; Figueira, José A; Rodrigues, Fátima P; Ornelas, Laura P; Branco, Ricardo N; Silva, Catarina L; Câmara, José S

    2014-10-01

    The volatile metabolomic patterns from different raw materials commonly used in beer production, namely barley, corn and hop-derived products - such as hop pellets, hop essential oil from Saaz variety and tetra-hydro isomerized hop extract (tetra hop), were established using a suitable analytical procedure based on dynamic headspace solid-phase microextraction (HS-SPME) followed by thermal desorption gas chromatography-quadrupole mass spectrometry detection (GC-qMS). Some SPME extraction parameters were optimized. The best results, in terms of maximum signal recorded and number of isolated metabolites, were obtained with a 50/30 μm DVB/CAR/PDMS coating fiber at 40 °C for 30 min. A set of 152 volatile metabolites comprising ketones (27), sesquiterpenes (26), monoterpenes (19), aliphatic esters (19), higher alcohols (15), aldehydes (11), furan compounds (11), aliphatic fatty acids (9), aliphatic hydrocarbons (8), sulphur compounds (5) and nitrogen compounds (2) were positively identified. Each raw material showed a specific volatile metabolomic profile. Monoterpenes in hop essential oil and corn, sesquiterpenes in hop pellets, ketones in tetra hop and aldehydes and sulphur compounds in barley were the predominant chemical families in the targeted beer raw materials. β-Myrcene was the most dominant volatile metabolite in hop essential oil, hop pellets and corn samples while, in barley, the predominant volatile metabolites were dimethyl sulphide and 3-methylbutanal and, in tetra hop, 6-methyl-2-pentanone and 4-methyl-2-pentanone. Principal component analysis (PCA) showed natural sample grouping among beer raw materials.

  8. Thermoplastic Polyurethane Elastomer Nanocomposites: Morphology, Thermophysical, and Flammability Properties

    Directory of Open Access Journals (Sweden)

    Wai K. Ho

    2010-01-01

    Full Text Available Novel materials based on nanotechnology creating nontraditional ablators are rapidly changing the technology base for thermal protection systems. Formulations with the addition of nanoclays and carbon nanofibers in a neat thermoplastic polyurethane elastomer (TPU were melt-compounded using twin-screw extrusion. The TPU nanocomposites (TPUNs are proposed to replace Kevlar-filled ethylene-propylene-diene-monomer rubber, the current state-of-the-art solid rocket motor internal insulation. Scanning electron microscopy analysis was conducted to study the char characteristics of the TPUNs at elevated temperatures. Specimens were examined to analyze the morphological microstructure during the pyrolysis reaction and in fully charred states. Thermophysical properties of density, specific heat capacity, thermal diffusivity, and thermal conductivity of the different TPUN compositions were determined. To identify dual usage of these novel materials, cone calorimetry was employed to study the flammability properties of these TPUNs.

  9. The Chemistry of Flammable Gas Generation

    Energy Technology Data Exchange (ETDEWEB)

    ZACH, J.J.

    2000-10-30

    The document collects information from field instrumentation, laboratory tests, and analytical models to provide a single source of information on the chemistry of flammable gas generation at the Hanford Site. It considers the 3 mechanisms of formation: radiolysis, chemical reactions, and thermal generation. An assessment of the current models for gas generation is then performed. The results are that the various phenomena are reasonably understood and modeled compared to field data.

  10. Method for Predicting Hypergolic Mixture Flammability Limits

    Science.gov (United States)

    2017-02-01

    AFRL-AFOSR-UK-TR-2017-0003 Method for Predicting Hypergolic Mixture Flammability Limits Laurent Catoire Ecole Nat Sup De Techniques Avancees Final...TASK NUMBER 5f.  WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Ecole Nat Sup De Techniques Avancees 828, Boulevard Des Marechaux...provides a mitigation strategy to reduce the risk of failure for the insertion of IL fuel technology into the small satellite market as AFRL/RQRP

  11. Effect of electrode material on characteristics of non-volatile resistive memory consisting of Ag2S nanoparticles

    Science.gov (United States)

    Jang, Jaewon

    2016-07-01

    In this study, Ag2S nanoparticles are synthesized and used as the active material for two-terminal resistance switching memory devices. Sintered Ag2S films are successfully crystallized on plastic substrates with synthesized Ag2S nanoparticles, after a relatively low-temperature sintering process (200 °C). After the sintering process, the crystallite size is increased from 6.8 nm to 80.3 nm. The high ratio of surface atoms to inner atoms of nanoparticles reduces the melting point temperature, deciding the sintering process temperature. In order to investigate the resistance switching characteristics, metal/Ag2S/metal structures are fabricated and tested. The effect of the electrode material on the non-volatile resistive memory characteristics is studied. The bottom electrochemically inert materials, such as Au and Pt, were critical for maintaining stable memory characteristics. By using Au and Pt inert bottom electrodes, we are able to significantly improve the memory endurance and retention to more than 103 cycles and 104 sec, respectively.

  12. Production of hydrogen and volatile fatty acid by Enterobacter sp. T4384 using organic waste materials.

    Science.gov (United States)

    Kim, Byung-Chun; Deshpande, Tushar R; Chun, Jongsik; Yi, Sung Chul; Kim, Hyunook; Um, Youngsoon; Sang, Byoung-In

    2013-02-01

    In a study of hydrogen-producing bacteria, strain T4384 was isolated from rice field samples in the Republic of Korea. The isolate was identified as Enterobacter sp. T4384 by phylogenetic analysis of 16S rRNA and rpoB gene sequences. Enterobacter sp. T4384 grew at a temperature range of 10-45 degrees C and at an initial pH range of 4.5-9.5. Strain T4384 produced hydrogen at 0-6% NaCl by using glucose, fructose, and mannose. In serum bottle cultures using a complete medium, Enterobacter sp. T4384 produced 1,098 ml/l H2, 4.0 g/l ethanol, and 1.0 g/l acetic acid. In a pH-regulated jar fermenter culture with the biogas removed, 2,202 ml/l H2, 6.2 g/l ethanol, and 1.0 g/l acetic acid were produced, and the lag-phase time was 4.8 h. Strain T4384 metabolized the hydrolysate of organic waste for the production of hydrogen and volatile fatty acid. The strain T4384 produced 947 ml/l H2, 3.2 g/l ethanol, and 0.2 g/l acetic acid from 6% (w/v) food waste hydrolysate; 738 ml/l H2, 4.2 g/l ethanol, and 0.8 g/l acetic acid from Miscanthus sinensis hydrolysate; and 805 ml/l H2, 5.0 g/l ethanol, and 0.7 g/l acetic acid from Sorghum bicolor hydrolysate.

  13. Predicted concentrations in new relocatable classrooms of volatile organic compounds emitted from standard and alternate interior finish materials

    Energy Technology Data Exchange (ETDEWEB)

    Hodgson, Alfred T.; Fisk, William J.; Shendell, Derek G.; Apte, Michael G.

    2001-07-01

    Relocatable classrooms (RCs) are widely employed by California school districts to satisfy rapidly expanding space requirements due to population growth and class size reduction policies. There is public concern regarding indoor environmental quality (IEQ) in schools, particularly in RCs, but very little data to support or dispel these concerns. Several studies are investigating various aspects of IEQ in California schools. This laboratory-based study focused on evaluating the emissions of toxic and/or odorous volatile organic compounds (VOCs), including formaldehyde and acetaldehyde, from materials used to finish the interiors of new RCs. Furthermore, the study implemented a procedure for VOC source reduction by testing and selecting lower-emitting materials as substitutes for standard materials. In total, 17 standard and alternate floor coverings, wall panels and ceiling panels were quantitatively tested for emissions of VOCs using smallscale environmental chambers. Working with the largest northern California manufacturer of conventional RCs and two school districts, specifications were developed for four new RCs to be produced in early summer 2001. Two of these will be predominantly finished with standard materials. Alternate carpet systems, an alternate wall panel covering and an alternate ceiling panel were selected for the two other RCs based on the results of the laboratory study and considerations of cost and anticipated performance and maintenance. Particular emphasis was placed on reducing the concentrations of VOCs on California agency lists of toxic compounds. Indoor concentrations of toxic and odorous VOCs were estimated for the four classrooms by mass balance using the measured VOC emission factors, exposed surface areas of the materials in the RCs, and three ventilation rate scenarios. Results indicate that reductions in the concentrations of formaldehyde, acetaldehyde phenol, di(ethylene glycol) butyl ether, vinyl acetate, 1,2,4-trimethylbenzene

  14. Flammability of self-extinguishing kenaf/ABS nanoclays composite for aircraft secondary structure

    Science.gov (United States)

    Karunakaran, S.; Majid, D. L.; Mohd Tawil, M. L.

    2016-10-01

    This study investigates the flammability properties of kenaf fiber reinforced acrylonitrile butadiene styrene (ABS) with nanoclays composites. Natural fiber is one of the potential materials to be used with thermoplastic as a composite due to its attractive properties such as lightweight and strong. In this paper, flammability properties of this material are evaluated through Underwriters Laboratory 94 Horizontal Burning (UL94 HB), which has been conducted for both controlled and uncontrolled conditions, smoke density and limiting oxygen index tests (LOI). These flammability tests are in compliance with the Federal Aviation Regulation (FAR) requirement. The results from UL94 HB and smoke density tests show that the presence of nanoclays with effective composition of kenaf fiber reinforced ABS has enhanced the burning characteristics of the material by hindering propagation of flame spread over the surface of the material through char formation. Consequently, this decreases the burning rate and produces low amount of smoke during burning. On contrary, through LOI test, this material requires less oxygen to burn when exposed to fire, which hinders the enhancement of burning characteristics. This is due to burning mechanism exhibited by nanoclays that catalyzes barrier formation and flame propagation rate over the surface of the biocomposite material. Overall, these experimental results suggest that this biocomposite material is capable of self-extinguishing and possesses effective fire extinction. The observed novel synergism from the result obtained is promising to be implemented in secondary structures of aircraft with significant benefits such as cost-effective, lightweight and biodegradable self-extinguishing biocomposite.

  15. Flammability limits of silane/perfluorocarbon/nitrogen mixtures

    OpenAIRE

    Ohtani, Hideo

    2004-01-01

    Perfluorocarbons are known to react with silane because silane is a very strong reducing agent. However, quantitative information on their explosion limits are not known. So, in this study, flammability of silane/perfluorocarbon/nitrogen was examined experimentally. Their flammability areas were revealed quantitatively as triangular flammability diagrams, and the fact that perfluorocarbon reacts with silane was ascertained. (C) 2004 Elsevier Ltd.. All rights reserved.

  16. MESERAN Test Results for Elimination of Flammable Solvents in Wipe Applications at Pantex

    Energy Technology Data Exchange (ETDEWEB)

    M. G. Benkovich

    2005-03-30

    In recent years, efforts have been made within the nuclear weapons complex (National Nuclear Security Administration) of the Department of Energy (DOE) to replace Resource Conservation and Recovery Act (RCRA) regulated solvents (i.e., flammable, toxic, corrosive, and reactive) and ozone-depleting chemicals (ODC) with more benign alternatives. Within the National Nuclear Security Administration (NNSA) and the Department of Defense (DoD) sectors, these solvents are used for cleaning hardware during routine maintenance operations. A primary goal of this study is to replace flammable solvents for wiping applications. Two cleaners, including a hydrofluoroether (HFE) and an azeotrope of the HFE and isopropyl alcohol (IPA), have been studied as potential replacements for flammable solvents. Cleaning efficacy, short-term and longterm materials compatibility, corrosion, drying times, flammability, environment, safety and health (ES&H) issues and accelerated aging studies are among the tests that are being conducted and that are used to screen candidate solvents by the interagency team performing this work. The results are compared to the traditionally used isopropyl alcohol, which serves as the baseline cleaner. This report details the results of MESERAN (Measurement and Evaluation of Surfaces by Evaporative Rate ANalysis) testing performed at the Kansas City Plant (KCP) to quantify the cleaning efficacy on samples contaminated with the various contaminants and cleaned by wiping with the various solvents being evaluated.

  17. Effect of Raw Material, Pressing and Glycosidase on the Volatile Compound Composition of Wine Made From Goji Berries.

    Science.gov (United States)

    Yuan, Guanshen; Ren, Jie; Ouyang, Xiaoyu; Wang, Liying; Wang, Mengze; Shen, Xiaodong; Zhang, Bolin; Zhu, Baoqing

    2016-10-02

    This study investigated the effect of raw material, pressing, and glycosidase on the aromatic profile of goji berry wine. The free-run and the pressed juice of dried and fresh goji berries were used for wine production, whereas glycosidase was applied to wine after fermentation. Dried goji berry fermented wine exhibited much stronger fruity, floral, caramel, and herbaceous odors due to higher levels of esters, β-ionone and methionol. However, fresh berry fermented wine possessed stronger chemical notes due to higher levels of 4-ethylphenol. Pressing treatment reduced the fruity and caramel odors in these fermented wines, and fresh berry free-run juice fermented wine exhibited the least floral aroma. Glycosidase addition did not alter the aromatic composition of wines. The principal component analysis indicated that goji raw material played a primary role in differentiating the aromatic profiles of the wines due to the difference on the content of 20 esters, nine benzenes, eight aldehydes/ketones, three acids, two alcohols and six other volatiles. The content differences on isopentyl alcohol, styrene, benzyl alcohol, 1-octanol, (E)-5-decen-1-ol, 1-hexanol, and β-cyclocitral resulted in the segregation of the wines with and without the pressing treatment, especially for fresh berry fermented wine.

  18. Effect of Raw Material, Pressing and Glycosidase on the Volatile Compound Composition of Wine Made From Goji Berries

    Directory of Open Access Journals (Sweden)

    Guanshen Yuan

    2016-10-01

    Full Text Available This study investigated the effect of raw material, pressing, and glycosidase on the aromatic profile of goji berry wine. The free-run and the pressed juice of dried and fresh goji berries were used for wine production, whereas glycosidase was applied to wine after fermentation. Dried goji berry fermented wine exhibited much stronger fruity, floral, caramel, and herbaceous odors due to higher levels of esters, β-ionone and methionol. However, fresh berry fermented wine possessed stronger chemical notes due to higher levels of 4-ethylphenol. Pressing treatment reduced the fruity and caramel odors in these fermented wines, and fresh berry free-run juice fermented wine exhibited the least floral aroma. Glycosidase addition did not alter the aromatic composition of wines. The principal component analysis indicated that goji raw material played a primary role in differentiating the aromatic profiles of the wines due to the difference on the content of 20 esters, nine benzenes, eight aldehydes/ketones, three acids, two alcohols and six other volatiles. The content differences on isopentyl alcohol, styrene, benzyl alcohol, 1-octanol, (E-5-decen-1-ol, 1-hexanol, and β-cyclocitral resulted in the segregation of the wines with and without the pressing treatment, especially for fresh berry fermented wine.

  19. Measurement of fine particulate matter nonvolatile and semi-volatile organic material with the Sunset Laboratory Carbon Aerosol Monitor.

    Science.gov (United States)

    Grover, Brett D; Kleinman, Michael; Eatough, Norman L; Eatough, Delbert J; Cary, Robert A; Hopke, Philip K; Wilson, William E

    2008-01-01

    Semi-volatile organic material (SVOM) in fine particles is not reliably measured with conventional semicontinuous carbon monitors because SVOM is lost from the collection media during sample collection. We have modified a Sunset Laboratory Carbon Aerosol Monitor to allow for the determination of SVOM. In a conventional Sunset monitor, gas-phase organic compounds are removed in the sampled airstream by a diffusion denuder employing charcoal-impregnated cellulose filter (CIF) surfaces. Subsequently, particles are collected on a quartz filter and the instrument then determines both the organic carbon and elemental carbon fractions of the aerosol using a thermal/optical method. However, some of the SVOM is lost from the filter during collection, and therefore is not determined. Because the interfering gas-phase organic compounds are removed before aerosol collection, the SVOM can be determined by filtering the particles at the instrument inlet and then replacing the quartz filter in the monitor with a charcoal-impregnated glass fiber filter (CIG), which retains the SVOM lost from particles collected on the inlet filter. The resulting collected SVOM is then determined in the analysis step by measurement of the carbonaceous material thermally evolved from the CIG filter. This concept was tested during field studies in February 2003 in Lindon, UT, and in July 2003 in Rubidoux, CA. The results obtained were validated by comparison with Particle Concentrator-Brigham Young University Organic Sampling System (PC-BOSS) results. The sum of nonvolatile organic material determined with a conventional Sunset monitor and SVOM determined with the modified Sunset monitor agree with the PC-BOSS results. Linear regression analysis of total carbon concentrations determined by the PC-BOSS and the Sunset resulted in a zero-intercept slope of 0.99 +/- 0.02 (R2 = 0.92) and a precision of sigma = +/- 1.5 microg C/m3 (8%).

  20. Steady State Flammable Gas Release Rate Calculation and Lower Flammability Level Evaluation for Hanford Tank Waste

    Energy Technology Data Exchange (ETDEWEB)

    HU, T.A.

    2000-04-27

    This work is to assess the steady-state flammability level at normal and off-normal ventilation conditions in the tank dome space for 177 double-shell and single-shell tanks at Hanford. Hydrogen generation rate was calculated for 177 tanks using rate equation model developed recently.

  1. Volatile organic compounds (VOCs) in surface coating materials: Their compositions and potential as an alternative fuel.

    Science.gov (United States)

    Dinh, Trieu-Vuong; Choi, In-Young; Son, Youn-Suk; Song, Kyu-Yong; Sunwoo, Young; Kim, Jo-Chun

    2016-03-01

    A sampling system was designed to determine the composition ratios of VOCs emitted from 31 surface coating materials (SCMs). Representative architectural, automotive, and marine SCMs in Korea were investigated. Toluene, ethylbenzene, and xylene were the predominant VOCs. The VOC levels (wt%) from automotive SCMs were significantly higher than those from architectural and marine paints. It was found that target SCMs comprised mainly VOCs with 6-10 carbon atoms in molecules, which could be adsorbed by activated carbon. The saturated activated carbon which had already adsorbed toluene, ethylbenzene, and m-xylene was combusted. The saturated activated carbon was more combustible than new activated carbon because it comprised inflammable VOCs. Therefore, it could be an alternative fuel when using in a "fuelization system". To use the activated carbon as a fuel, a control technology of VOCs from a coating process was also designed and introduced.

  2. Fast sorption measurements of volatile organic compounds on building materials: Part 1 – Methodology developed for field applications

    Directory of Open Access Journals (Sweden)

    M. Rizk

    2016-03-01

    Full Text Available A Proton Transfer Reaction-Mass Spectrometer (PTR-MS has been coupled to the outlet of a Field and Laboratory Emission Cell (FLEC, to measure volatile organic compounds (VOC concentration during a sorption experiments (Rizk et al., this issue [1]. The limits of detection of the PTR-MS for three VOCs are presented for different time resolution (2, 10 and 20 s. The mass transfer coefficient was calculated in the FLEC cavity for the different flow rates. The concentration profile obtained from a sorption experiment performed on a gypsum board and a vinyl flooring are also presented in comparison with the profile obtained for a Pyrex glass used as a material that do not present any sorption behavior (no sink. Finally, the correlation between the concentration of VOCs adsorbed on the surface of the gypsum board at equilibrium (Cse and the concentration of VOCs Ce measured in the gas phase at equilibrium is presented for benzene, C8 aromatics and toluene.

  3. Barrier Properties of Polymeric Packaging Materials to Major Aroma Volatiles in Herbs

    Directory of Open Access Journals (Sweden)

    Leelaphiwat Pattarin

    2016-01-01

    Full Text Available This study determined the main transport coefficients (diffusion, solubility and permeability of key aroma compounds present in tropical herbs (eucalyptol and estragol through low‒density polyethylene (LDPE, polypropylene (PP, nylon (Nylon, polyethylene terephthalate (PET, metalized‒polyethylene terephthalate (MPET and poly(lactic acid (PLA films at 15 and 25 °C. The concentration of aroma compounds permeating through the films were evaluated at various time intervals using a gas chromatograph flame ionization detector (GC–FID. Results showed that the diffusion coefficients of aroma compounds were highest in LDPE whereas the solubility coefficients were highest in PLA at both temperatures. PLA had the highest permeability coefficients for estragol at both temperatures. PP and LDPE had the highest permeability coefficients for eucalyptol at 15 and 25 °C, respectively. MPET had the lowest permeability for both aroma compounds studied. Aroma barrier properties can be used when selecting polymeric packaging materials to prevent aroma loss in various food and consumer products.

  4. 30 CFR 57.4460 - Storage of flammable liquids underground.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Storage of flammable liquids underground. 57... AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES... liquids underground. (a) Flammable liquids shall not be stored underground, except— (1) Small quantities...

  5. Significance of the carbonization of volatile pyrolytic products on the properties of activated carbons from phosphoric acid activation of lignocellulosic material

    Energy Technology Data Exchange (ETDEWEB)

    Zuo, Songlin; Yang, Jianxiao; Cai, Xuan [Faculty of Chemical Engineering, Nanjing Forestry University, Nanjing 210037 (China); Liu, Junli [Institute of Chemical Industry of Forest Products, CAF, Nanjing 210042 (China)

    2009-07-15

    Two series of activated carbons derived from China fir (Cunninghamia lanceolata) wood impregnated with phosphoric acid were prepared in a cylindrical container that was kept in a closed state covered with a lid (the covered case) or in an open state. The effects of the carbonization of volatile pyrolytic products of starting materials on the properties of activated carbon were investigated in the process of phosphoric acid activation. Elemental analysis and SEM observation showed that both activating in the covered case and increasing the mass of starting material used favored the carbonization of volatile pyrolytic products. An investigation of N{sub 2} adsorption isotherms revealed that the carbonization of volatile pyrolytic products significantly enhanced mesopore development in the final carbons, especially pores with a size range from 2.5 to 30 nm, with little influence on micropores, and therefore produced a large increase in the adsorption capacity to Vitamin B12 (with a molecular size of 2.09 nm). Activated carbons with highly developed mesopores could be obtained in the covered case. The carbonization mechanism of volatiles was discussed and two different carbonization pathways (in solid and gas phases) were proposed during phosphoric acid activation. (author)

  6. A study on flammability limits of fuel mixtures.

    Science.gov (United States)

    Kondo, Shigeo; Takizawa, Kenji; Takahashi, Akifumi; Tokuhashi, Kazuaki; Sekiya, Akira

    2008-07-15

    Flammability limit measurements were made for various binary and ternary mixtures prepared from nine different compounds. The compounds treated are methane, propane, ethylene, propylene, methyl ether, methyl formate, 1,1-difluoroethane, ammonia, and carbon monoxide. The observed values of lower flammability limits of mixtures were found to be in good agreement to the calculated values by Le Chatelier's formula. As for the upper limits, however, some are close to the calculated values but some are not. It has been found that the deviations of the observed values of upper flammability limits from the calculated ones are mostly to lower concentrations. Modification of Le Chatelier's formula was made to better fit to the observed values of upper flammability limits. This procedure reduced the average difference between the observed and calculated values of upper flammability limits to one-third of the initial value.

  7. Applying Flammability Limit Probabilities and the Normoxic Upward Limiting Pressure Concept to NASA STD-6001 Test 1

    Science.gov (United States)

    Olson, Sandra L.; Beeson, Harold; Fernandez-Pello, A. Carlos

    2014-01-01

    Repeated Test 1 extinction tests near the upward flammability limit are expected to follow a Poisson process trend. This Poisson process trend suggests that rather than define a ULOI and MOC (which requires two limits to be determined), it might be better to define a single upward limit as being where 1/e (where e (approx. equal to 2.7183) is the characteristic time of the normalized Poisson process) of the materials burn, or, rounding, where approximately 1/3 of the samples fail the test (and burn). Recognizing that spacecraft atmospheres will not bound the entire oxygen-pressure parameter space, but actually lie along the normoxic atmosphere control band, we can focus the materials flammability testing along this normoxic band. A Normoxic Upward Limiting Pressure (NULP) is defined that determines the minimum safe total pressure for a material within the constant partial pressure control band. Then, increasing this pressure limit by a factor of safety, we can define the material as being safe to use at the NULP + SF (where SF is on the order of 10 kilopascal, based on existing flammability data). It is recommended that the thickest material to be tested with the current Test 1 igniter should be 3 mm thick (1/8 inches) to avoid the problem of differentiating between an ignition limit and a true flammability limit.

  8. Flammability control in the oxygen environment of the Apollo guidance and navigation equipment

    Science.gov (United States)

    Holley, M. D.; Bachman, S.

    1971-01-01

    The Apollo guidance and navigation (G&N) equipment test program, the redesign philosophy, and the actual equipment modifications that were used to limit burn rates in an environment of 100 percent oxygen at pressures of 6.2 and 16 psia are described. The major approach was a serious basic review of the real function of the nonmetallic materials of concern. The result of this review was that the materials could be replaced, eliminated, or covered by nonflammable metallic materials. Although several low-flammability nonmetallic materials were investigated, the direct approach of cover, eliminate, or replace generally proved to be quicker and more effective.

  9. Investigations into the effects of volatile biomass tar on the performance of Fe-based CLC oxygen carrier materials

    Science.gov (United States)

    Boot-Handford, Matthew E.; Florin, Nick; Fennell, Paul S.

    2016-11-01

    In this study we present findings from investigations into interactions between biomass tar and two iron based oxygen carrier materials (OCMs) designed for chemical-looping applications: a 100% Fe2O3 (100Fe) OCM and a 60 wt% Fe2O3/40 wt% Al2O3 (60Fe40Al) OCM. A novel 6 kWe two-stage, fixed-bed reactor was designed and constructed to simulate a chemical-looping combustion (CLC) process with ex situ gasification of biomass. Beech wood was pyrolysed in the first stage of the reactor at 773 K to produce a tar-containing fuel gas that was used to reduce the OCM loaded into the 2nd stage at 973 K. The presence of either OCM was found to significantly reduce the amount of biomass tars exiting the reactor by up to 71 wt% compared with analogous experiments in which the biomass tar compounds were exposed to an inert bed of sand. The tar cracking effect of the 60Fe40Al OCM was slightly greater than the 100Fe OCM although the reduction in the tar yield was roughly equivalent to the increase in carbon deposition observed for the 60Fe40Al OCM compared with the 100Fe OCM. In both cases, the tar cracking effect of the OCMs appeared to be independent of the oxidation state in which the OCM was exposed to the volatile biomass pyrolysis products (i.e. Fe2O3 or Fe3O4). Exposing the pyrolysis vapours to the OCMs in their oxidised (Fe2O3) form favoured the production of CO2. The production of CO was favoured when the OCMs were in their reduced (Fe3O4) form. Carbon deposition was removed in the subsequent oxidation phase with no obvious deleterious effects on the reactivity in subsequent CLC cycles with reduction by 3 mol% CO.

  10. Volatility Discovery

    DEFF Research Database (Denmark)

    Dias, Gustavo Fruet; Scherrer, Cristina; Papailias, Fotis

    The price discovery literature investigates how homogenous securities traded on different markets incorporate information into prices. We take this literature one step further and investigate how these markets contribute to stochastic volatility (volatility discovery). We formally show...... that the realized measures from homogenous securities share a fractional stochastic trend, which is a combination of the price and volatility discovery measures. Furthermore, we show that volatility discovery is associated with the way that market participants process information arrival (market sensitivity...

  11. Volatile Metabolites

    Directory of Open Access Journals (Sweden)

    Daryl D. Rowan

    2011-11-01

    Full Text Available Volatile organic compounds (volatiles comprise a chemically diverse class of low molecular weight organic compounds having an appreciable vapor pressure under ambient conditions. Volatiles produced by plants attract pollinators and seed dispersers, and provide defense against pests and pathogens. For insects, volatiles may act as pheromones directing social behavior or as cues for finding hosts or prey. For humans, volatiles are important as flavorants and as possible disease biomarkers. The marine environment is also a major source of halogenated and sulfur-containing volatiles which participate in the global cycling of these elements. While volatile analysis commonly measures a rather restricted set of analytes, the diverse and extreme physical properties of volatiles provide unique analytical challenges. Volatiles constitute only a small proportion of the total number of metabolites produced by living organisms, however, because of their roles as signaling molecules (semiochemicals both within and between organisms, accurately measuring and determining the roles of these compounds is crucial to an integrated understanding of living systems. This review summarizes recent developments in volatile research from a metabolomics perspective with a focus on the role of recent technical innovation in developing new areas of volatile research and expanding the range of ecological interactions which may be mediated by volatile organic metabolites.

  12. 46 CFR 30.10-39 - Liquefied flammable gas-TB/ALL.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Liquefied flammable gas-TB/ALL. 30.10-39 Section 30.10-39 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS GENERAL PROVISIONS Definitions § 30.10-39 Liquefied flammable gas—TB/ALL. The term liquefied flammable gas means any flammable gas...

  13. Testing and analysis of a modernized freight wagon's elements flammability

    Science.gov (United States)

    Płaczek, M.; Wróbel, A.; Baier, A.

    2016-08-01

    Paper concerns an issue of freight wagon modernization using composite materials. The goal of the project is to elongate the period between repairs (by better corrosion protection) and improve conditions of exploitation of modernized freight wagons (for example easier unloading during winter conditions - no freezes of the charge to the freight wagon body shell). Application of the composite panels to the freight wagon's body shell was proposed as the solution that can solve mentioned problems. The composite panels composed of fiberglass and epoxy resin were proposed. They will be mounted on the body shell using rivet nuts. What is more the body shell of the modernized freight wagon will be painted using an anti-corrosion agent. In this paper the analysis of a flammability of the proposed composition (the composite plate made of fiberglass and epoxy resin mounted to the steel sheet with additional anticorrosion agent) is presented. In the paper results of laboratory tests conducted according to international standards are presented. A series of samples of elements of modernized freight wagons was tested using the created laboratory stand. Obtained results were averaged and the proposed material was assigned to the one of the class of materials for their combustibility.

  14. Flammability of Gas-Filled Polymers

    Directory of Open Access Journals (Sweden)

    Ushkov Valentin Anatol'evich

    2017-09-01

    Full Text Available The regularities of flame propagation on the horizontal surface of gas-filled polymers are considered depending on the concentration of oxygen in the oxidizer flow. The values of the coefficients in the expression describing relationship between the rate of flame propagation on the surface of foams and oxygen concentration are obtained. It was shown that with the mass content of reactive organophosphorus compounds reaching 4.0...5.9%, non-smoldering resole foam plastics with high performance characteristics are obtained. It was found that in order to obtain moderately combustible polyurethane foams based on oxyethylated phosphorus-containing polyols, the phosphorus concentration should not exceed 3 % of mass. To obtain flame-retardant urea-formaldehyde foam cellular plastics, the concentration of phosphorus should not exceed 0.3 % of mass. Physical-mechanical properties and flammability indices of developed gas-filled polymers based on reactive oligomers are presented.

  15. FLAMMABLE GAS DIFFUSION THROUGH SINGLE SHELL TANK (SST) DOMES

    Energy Technology Data Exchange (ETDEWEB)

    MEACHAM, J.E.

    2003-11-10

    This report quantified potential hydrogen diffusion through Hanford Site Single-Shell tank (SST) domes if the SSTs were hypothetically sealed airtight. Results showed that diffusion would keep headspace flammable gas concentrations below the lower flammability limit in the 241-AX and 241-SX SST. The purpose of this document is to quantify the amount of hydrogen that could diffuse through the domes of the SSTs if they were hypothetically sealed airtight. Diffusion is assumed to be the only mechanism available to reduce flammable gas concentrations. The scope of this report is limited to the 149 SSTs.

  16. Collection and identification of human remains volatiles by non-contact, dynamic airflow sampling and SPME-GC/MS using various sorbent materials.

    Science.gov (United States)

    DeGreeff, Lauryn E; Furton, Kenneth G

    2011-09-01

    Human remains detection canines are used in locating deceased humans in diverse scenarios and environments based on odor produced during the decay process of the human body. It has been established that human remains detection canines are capable of locating human remains specifically, as opposed to living humans or animal remains, thus suggesting a difference in odor between the different sources. This work explores the collection and determination of such odors using a dynamic headspace concentration device. The airflow rate and three sorbent materials-Dukal cotton gauze, Johnson & Johnson cotton-blend gauze, and polyester material-used for odor collection were evaluated using standard compounds. It was determined that higher airflow rates and openly woven material, e.g., Dukal cotton gauze, yielded significantly less total volatile compounds due to compound breakthrough through the sorbent material. Collection from polymer- and cellulose-based materials demonstrated that the molecular backbone of the material is a factor in compound collection as well. Volatiles, including cyclic and straight-chain hydrocarbons, organic acids, sulfides, aldehydes, ketones, and alcohols, were collected from a population of 27 deceased bodies from two collection locations. The common compounds between the subjects were compared and the odor profiles were determined. These odor profiles were compared with those of animal remains and living human subjects collected in the same manner. Principal component analysis showed that the odor profiles of the three sample types were distinct.

  17. New UPLC coupled to mass spectrometry approaches for screening of non-volatile compounds as potential migrants from adhesives used in food packaging materials.

    Science.gov (United States)

    Canellas, E; Nerín, C; Moore, R; Silcock, P

    2010-05-07

    The objective of this study was to identify the non-volatile compounds as potential migrants from adhesives used in food packaging. A number of the current acrylic adhesive formulations were extracted and prepared for analysis. The extracts were screened using ultra-performance liquid chromatography coupled to a time-of-flight mass spectrometer detector (UPLC-TOF-MS). This approach allowed the identification of several components by a combination of exact mass and in-source collision induced dissociation (CID). Due to the lack of freely available information on adhesive formulations further analyses were undertaken using ultra-performance liquid chromatography coupled to high definition mass spectrometry (UPLC-HDMS). Using the Mass Fragment tool to interrogate fragmentation data, a wide series of compounds were identified, demonstrating the usefulness and importance of these tools for difficult problems. Moreover, using several packaging materials containing adhesives, qualitative migration tests were performed with Tenax as a food simulant. Several non-volatile compounds were identified as well in the Tenax which emphasizes the importance of this work and demonstrates that even the non-volatile compounds have the potential to migrate into food which is in contact with packaging materials. The main characteristics of the screening study and the results obtained are shown and discussed.

  18. 49 CFR 176.400 - Stowage of Division 1.5, Class 4 (flammable solids) and Class 5 (oxidizers and organic peroxides...

    Science.gov (United States)

    2010-10-01

    ...) and Class 5 (oxidizers and organic peroxides) materials. 176.400 Section 176.400 Transportation Other... Solids), Class 5 (Oxidizers and Organic Peroxides), and Division 1.5 Materials § 176.400 Stowage of Division 1.5, Class 4 (flammable solids) and Class 5 (oxidizers and organic peroxides) materials. (a)...

  19. DOE/DOE Tight Oil Flammability & Transportation Spill Safety

    Energy Technology Data Exchange (ETDEWEB)

    Lord, David L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-12-01

    This presentation describes crude oils, their phase behavior, the SPR vapor pressure program, and presents data comparisons from various analytical techniques. The overall objective is to describe physical properties of crude oil relevant to flammability and transport safety

  20. Offsite Radiological Consequence Analysis for the Bounding Flammable Gas Accident

    CERN Document Server

    Carro, C A

    2003-01-01

    This document quantifies the offsite radiological consequences of the bounding flammable gas accident for comparison with the 25 rem Evaluation Guideline established in DOE-STD-3009, Appendix A. The bounding flammable gas accident is a detonation in a single-shell tank The calculation applies reasonably conservation input parameters in accordance with DOE-STD-3009, Appendix A, guidance. Revision 1 incorporates comments received from Office of River Protection.

  1. Electrical safety in flammable gas/vapor laden atmospheres

    CERN Document Server

    Korver, WOE

    1992-01-01

    This book provides comprehensive coverage of electrical system installation within areas where flammable gases and liquids are handled and processed. The accurate hazard evaluation of flammability risks associated with chemical and petrochemical locations is critical in determining the point at which the costs of electrical equipment and installation are balanced with explosion safety requirements. The book offers the most current code requirements along with tables and illustrations as analytic tools. Environmental characteristics are covered in Section 1 along with recommended electrical ins

  2. Effect of a zero g environment on flammability limits as determined using a standard flammability tube apparatus

    Science.gov (United States)

    Strehlow, R. A.; Reuss, D. L.

    1980-01-01

    Flammability limits in a zero gravity environment were defined. Key aspects of a possible spacelab experiment were investigated analytically, experimentally on the bench, and in drop tower facilities. A conceptual design for a spacelab experiment was developed.

  3. Virtual volatility

    Science.gov (United States)

    Silva, A. Christian; Prange, Richard E.

    2007-03-01

    We introduce the concept of virtual volatility. This simple but new measure shows how to quantify the uncertainty in the forecast of the drift component of a random walk. The virtual volatility also is a useful tool in understanding the stochastic process for a given portfolio. In particular, and as an example, we were able to identify mean reversion effect in our portfolio. Finally, we briefly discuss the potential practical effect of the virtual volatility on an investor asset allocation strategy.

  4. Virtual volatility

    OpenAIRE

    A. Christian Silva; Prange, Richard E.

    2006-01-01

    We introduce the concept of virtual volatility. This simple but new measure shows how to quantify the uncertainty in the forecast of the drift component of a random walk. The virtual volatility also is a useful tool in understanding the stochastic process for a given portfolio. In particular, and as an example, we were able to identify mean reversion effect in our portfolio. Finally, we briefly discuss the potential practical effect of the virtual volatility on an investor asset allocation st...

  5. Plant volatiles.

    Science.gov (United States)

    Baldwin, Ian T

    2010-05-11

    Plant volatiles are the metabolites that plants release into the air. The quantities released are not trivial. Almost one-fifth of the atmospheric CO2 fixed by land plants is released back into the air each day as volatiles. Plants are champion synthetic chemists; they take advantage of their anabolic prowess to produce volatiles, which they use to protect themselves against biotic and abiotic stresses and to provide information - and potentially disinformation - to mutualists and competitors alike. As transferors of information, volatiles have provided plants with solutions to the challenges associated with being rooted in the ground and immobile.

  6. Model of ASTM Flammability Test in Microgravity: Iron Rods

    Science.gov (United States)

    Steinberg, Theodore A; Stoltzfus, Joel M.; Fries, Joseph (Technical Monitor)

    2000-01-01

    There is extensive qualitative results from burning metallic materials in a NASA/ASTM flammability test system in normal gravity. However, this data was shown to be inconclusive for applications involving oxygen-enriched atmospheres under microgravity conditions by conducting tests using the 2.2-second Lewis Research Center (LeRC) Drop Tower. Data from neither type of test has been reduced to fundamental kinetic and dynamic systems parameters. This paper reports the initial model analysis for burning iron rods under microgravity conditions using data obtained at the LERC tower and modeling the burning system after ignition. Under the conditions of the test the burning mass regresses up the rod to be detached upon deceleration at the end of the drop. The model describes the burning system as a semi-batch, well-mixed reactor with product accumulation only. This model is consistent with the 2.0-second duration of the test. Transient temperature and pressure measurements are made on the chamber volume. The rod solid-liquid interface melting rate is obtained from film records. The model consists of a set of 17 non-linear, first-order differential equations which are solved using MATLAB. This analysis confirms that a first-order rate, in oxygen concentration, is consistent for the iron-oxygen kinetic reaction. An apparent activation energy of 246.8 kJ/mol is consistent for this model.

  7. Unstable volatility

    DEFF Research Database (Denmark)

    Casas, Isabel; Gijbels, Irène

    2012-01-01

    The objective of this paper is to introduce the break-preserving local linear (BPLL) estimator for the estimation of unstable volatility functions for independent and asymptotically independent processes. Breaks in the structure of the conditional mean and/or the volatility functions are common i...

  8. Unstable volatility

    DEFF Research Database (Denmark)

    Casas, Isabel; Gijbels, Irène

    2012-01-01

    The objective of this paper is to introduce the break-preserving local linear (BPLL) estimator for the estimation of unstable volatility functions for independent and asymptotically independent processes. Breaks in the structure of the conditional mean and/or the volatility functions are common i...

  9. Flammable Gas Detection for the D-Zero Gas System

    Energy Technology Data Exchange (ETDEWEB)

    Spires, L.D.; Foglesong, J.; /Fermilab

    1991-02-11

    The use of flammable gas and high voltage in detector systems is common in many experiments at Fermilab. To mitigate the hazards associated with these systems, Fermilab Engineering Standard SD-45B (Ref. 1) was adopted. Since this note is meant to be a guide and not a mandatory standard, each experiment is reviewed for compliance with SD-45B by the flammable gas safety subcommittee. Currently, there are only two types of flammable gas in use, ethane (Appendix A) and methane (Appendix B). The worst flammable-gas case is C2H6 (ethane), which has an estimated flow rate that is 73% of the CH4 (methane) flow but a heat of combustion (in kcal/g-mole) that is 173% of that of methane. In the worst case, if ethane were to spew through its restricting orifice into its gas line at 0 psig and then through a catastrophic leak into Room 215 (TRD) or Room 511 (CDC/FDCNTX), the time that would be required to build up a greater than Class 1 inventory (0.4kg H2 equivalent) would be 5.2 hours (Ref. 2). Therefore a worst-case flammable gas leak would have to go undetected for over 5 hours in order to transform a either mixing room to an environment with a Risk Class greater than Class 1. The mixing systems, gas lines, and detectors themselves will be thoroughly leak checked prior to active service. All vessels that are part of the mixing systems will be protected from overpressure by safety valves vented outside the building. Both the input and output of all detector volumes are protected from overpressure in the same way. The volume immediately outside the central tracking detectors is continuously purged by nitrogen from boiloff from the main nitrogen dewar at the site. However, if flammable gas were to build up in the mixing rooms or particular detector areas, no matter how unlikely, flammable gas detectors that are part of the interlock chain of each gas mixing system will shut down the appropriate system. This includes shutting off the output of flammable gas manifolds within the

  10. Use of wood-based materials in beef bedded manure packs: 2. Effect on odorous volatile organic compounds, odor activity value, , and nutrient concentrations.

    Science.gov (United States)

    Spiehs, Mindy J; Brown-Brandl, Tami M; Berry, Elaine D; Wells, James E; Parker, David B; Miller, Daniel N; Jaderborg, Jeffrey P; DiCostanzo, Alfred

    2014-07-01

    The objectives of this study were to determine the effects of three types of wood-based bedding materials (kiln-dried pine wood chips, dry cedar chips, and green cedar chips) and corn stover on the concentration of odorous volatile organic compounds (VOCs) and total in bedded pack material. Four bedded packs of each bedding material were maintained for two 42-d periods ( = 32; eight replicates/bedding material). Straight- and branched-chained fatty acids, aromatic compounds, and sulfide compounds were measured from the headspace above each bedded pack. Green cedar bedding had the highest concentration of odorous VOCs, and pine chip bedding had the lowest ( dry cedar, corn stover, and pine chip bedding. As the bedded packs aged, the concentration of odorous VOCs increased, particularly in the bedded packs containing green cedar chips and dry cedar chips. Total concentrations increased from Days 0 to 21 and then began to decline and were similar among all bedding materials ( < 0.10). Results of this study indicate that producers using a long-term bedded pack management in their facility may benefit from using pine chips because they do not appear to increase odor over time. Cedar-based bedding materials may be better suited for a scrape-and-haul system, where the bedded pack is removed after 1 or 2 wk. Total concentrations did not differ between any of the four bedding materials over time.

  11. [Advances of poly (ionic liquid) materials in separation science].

    Science.gov (United States)

    Liu, Cuicui; Guo, Ting; Su, Rina; Gu, Yuchen; Deng, Qiliang

    2015-11-01

    Ionic liquids, as novel ionization reagents, possess beneficial characteristics including good solubility, conductivity, thermal stability, biocompatibility, low volatility and non-flammability. Ionic liquids are attracting a mass of attention of analytical chemists. Poly (ionic liquid) materials have common performances of ionic liquids and polymers, and have been successfully applied in separation science area. In this paper, we discuss the interaction mechanisms between the poly(ionic liquid) materials and analytes including hydrophobic/hydrophilic interactions, hydrogen bond, ion exchange, π-π stacking and electrostatic interactions, and summarize the application advances of the poly(ionic liquid) materials in solid phase extraction, chromatographic separation and capillary electrophoresis. At last, we describe the future prospect of poly(ionic liquid) materials.

  12. Influence of oxygen and long term storage on the profile of volatile compounds released from polymeric multilayer food contact materials sterilized by gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Salafranca, Jesús, E-mail: fjsl@unizar.es [Aragón Institute of Engineering Research (I3A), EINA, Department of Analytical Chemistry, University of Zaragoza, María de Luna 3 (Torres Quevedo Bldg.), 50018 Zaragoza (Spain); Clemente, Isabel, E-mail: isabelclemente1984@gmail.com [Aragón Institute of Engineering Research (I3A), EINA, Department of Analytical Chemistry, University of Zaragoza, María de Luna 3 (Torres Quevedo Bldg.), 50018 Zaragoza (Spain); Isella, Francesca, E-mail: Francesca.Isella@goglio.it [Goglio S.p.A. Packaging Division, Via dell' Industria 7, 21020 Daverio (Italy); Nerín, Cristina, E-mail: cnerin@unizar.es [Aragón Institute of Engineering Research (I3A), EINA, Department of Analytical Chemistry, University of Zaragoza, María de Luna 3 (Torres Quevedo Bldg.), 50018 Zaragoza (Spain); Bosetti, Osvaldo, E-mail: Osvaldo.Bosetti@goglio.it [Goglio S.p.A. Packaging Division, Via dell' Industria 7, 21020 Daverio (Italy)

    2015-06-09

    Highlights: • 13 different food-use multilayers unirradiated and gamma-irradiated were studied. • 60–80 compounds/sample were identified by SPME–GC–MS even after 8-month storage. • Volatile profile of air- and N{sub 2}-filled bags greatly differed after irradiation. • Principal component analysis classified the samples into 4 groups. • Migration from irradiated materials to vapor phase was much lower than EU limits. - Abstract: The profile of volatile compounds released from 13 different multilayer polymeric materials for food use, before and after their exposure to gamma radiation, has been assessed by solid-phase microextraction–gas chromatography–mass spectrometry. Thermosealed bags of different materials were filled with either air or nitrogen to evaluate the oxygen influence. One-third of the samples were analyzed without irradiation, whereas the rest were irradiated at 15 and 25 kGy. Half of the samples were processed just after preparation and the other half was stored for 8 months at room temperature prior to analysis. Very significant differences between unirradiated and irradiated bags were found. About 60–80 compounds were released and identified per sample. A huge peak of 1,3-ditertbutylbenzene was present in most of the irradiated samples. An outstanding reproducibility in all the variables evaluated (chromatograms, oxygen percentage, volume of bags) was noticed. Independently of filling gas, the results of unirradiated materials were almost identical. In contrast, the chromatographic profile and the odor of irradiated bags filled with nitrogen were completely different to those filled with air. Principal component analysis was performed and 86.9% of the accumulated variance was explained with the first two components. The migration of compounds from irradiated materials to the vapor phase was much lower than the limits established in the Commission Regulation (EU) No 10/2011.

  13. On the temperature dependence of flammability limits of gases.

    Science.gov (United States)

    Kondo, Shigeo; Takizawa, Kenji; Takahashi, Akifumi; Tokuhashi, Kazuaki

    2011-03-15

    Flammability limits of several combustible gases were measured at temperatures from 5 to 100 °C in a 12-l spherical flask basically following ASHRAE method. The measurements were done for methane, propane, isobutane, ethylene, propylene, dimethyl ether, methyl formate, 1,1-difluoroethane, ammonia, and carbon monoxide. As the temperature rises, the lower flammability limits are gradually shifted down and the upper limits are shifted up. Both the limits shift almost linearly to temperature within the range examined. The linear temperature dependence of the lower flammability limits is explained well using a limiting flame temperature concept at the lower concentration limit (LFL)--'White's rule'. The geometric mean of the flammability limits has been found to be relatively constant for many compounds over the temperature range studied (5-100 °C). Based on this fact, the temperature dependence of the upper flammability limit (UFL) can be predicted reasonably using the temperature coefficient calculated for the LFL. However, some compounds such as ethylene and dimethyl ether, in particular, have a more complex temperature dependence.

  14. Chasing volatility

    DEFF Research Database (Denmark)

    Caporin, Massimiliano; Rossi, Eduardo; Santucci de Magistris, Paolo

    The realized volatility of financial returns is characterized by persistence and occurrence of unpreditable large increments. To capture those features, we introduce the Multiplicative Error Model with jumps (MEM-J). When a jump component is included in the multiplicative specification, the condi...... models, the introduction of the jump component provides a sensible improvement in the fit, as well as for in-sample and out-of-sample volatility tail forecasts....

  15. Volatility Risk

    OpenAIRE

    Zhiguang Wang

    2009-01-01

    Classical capital asset pricing theory tells us that riskaverse investors would require higher returns to compensate for higher risk on an investment. One type of risk is price (return) risk, which reflects uncertainty in the price level and is measured by the volatility (standard deviation) of asset returns. Volatility itself is also known to be random and hence is perceived as another type of risk. Investors can bear price risk in exchange for a higher return. But are investors willing to p...

  16. 49 CFR 193.2059 - Flammable vapor-gas dispersion protection.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Flammable vapor-gas dispersion protection. 193... Flammable vapor-gas dispersion protection. Each LNG container and LNG transfer system must have a dispersion... § 193.2013) with the following exceptions: (a) Flammable vapor-gas dispersion distances must be...

  17. 14 CFR Appendix M to Part 25 - Fuel Tank System Flammability Reduction Means

    Science.gov (United States)

    2010-01-01

    .... (a) The Fleet Average Flammability Exposure of each fuel tank, as determined in accordance with... failures of the FRM that occur in service that could increase any fuel tank's Fleet Average Flammability... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuel Tank System Flammability...

  18. 16 CFR Figure 1 to Part 1610 - Sketch of Flammability Apparatus

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Sketch of Flammability Apparatus 1 Figure 1 to Part 1610 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FLAMMABLE FABRICS ACT REGULATIONS STANDARD FOR THE FLAMMABILITY OF CLOTHING TEXTILES Pt.1610, Fig. 1 Figure 1 to Part 1610—Sketch...

  19. 46 CFR 30.10-21 - Flammable or inflammable-TB/ALL.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Flammable or inflammable-TB/ALL. 30.10-21 Section 30.10-21 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS GENERAL PROVISIONS Definitions § 30.10-21 Flammable or inflammable—TB/ALL. The words flammable and inflammable are interchangeable or...

  20. Cyclodextrin-functionalized reduced graphene oxide as a fiber coating material for the solid-phase microextraction of some volatile aromatic compounds.

    Science.gov (United States)

    Zhang, Shuaihua; Li, Zhi; Wang, Chun; Wang, Zhi

    2015-05-01

    A novel solid phase microextraction fiber was prepared for the first time by using a sol-gel technique with hydroxypropyl-β-cyclodextrin-functionalized reduced graphene oxide as the fiber coating material. The results verified that the β-cyclodextrin was successfully grafted onto the surface of reduced graphene oxide and the coating possessed a uniform folded and wrinkled structure. The performance of the solid phase microextraction fiber was evaluated by using it to extract nine volatile aromatic compounds from water samples before determination with gas chromatography and flame ionization detection. Some important experimental parameters that could affect the extraction efficiency such as the extraction time, extraction temperature, desorption temperature, desorption time, the volume of water sample solution, stirring rate, as well as ionic strength were optimized. The new method was validated to be effective for the trace analysis of some volatile aromatic compounds, with the limits of detection ranging from 2.0 to 8.0 ng/L. Single fiber repeatability and fiber-to-fiber reproducibility were in the range of 2.5-9.4 and 5.4-12.9%, respectively. The developed method was successfully applied to the analysis of three different water samples, and the recoveries of the method were in the range from 77.9 to 113.6% at spiking levels of 10, 100, and 1000 ng/L, respectively.

  1. SURVIAC Bulletin: Materials Flammability in Spacecraft, Volume 25 - Issue 1

    Science.gov (United States)

    2009-01-01

    shock or electrocute operators/repairmen • Cyber attack to disrupt production and distribution • Light aircraft suicide missions against plants and/or...provides solutions to eliminate and overcome the most signifi cant surveillance system problems. Jemez Technology’s Variant-iD technology provides an

  2. Setting the volatile composition of (exo)planet-building material. Does chemical evolution in disk midplanes matter?

    Science.gov (United States)

    Eistrup, Christian; Walsh, Catherine; van Dishoeck, Ewine F.

    2016-11-01

    Context. The atmospheres of extrasolar planets are thought to be built largely through accretion of pebbles and planetesimals. Such pebbles are also the building blocks of comets. The chemical composition of their volatiles are usually taken to be inherited from the ices in the collapsing cloud. However, chemistry in the protoplanetary disk midplane can modify the composition of ices and gases. Aims: To investigate if and how chemical evolution affects the abundances and distributions of key volatile species in the midplane of a protoplanetary disk in the 0.2-30 AU range. Methods: A disk model used in planet population synthesis models is adopted, providing temperature, density and ionisation rate at different radial distances in the disk midplane. A full chemical network including gas-phase, gas-grain interactions and grain-surface chemistry is used to evolve chemistry in time, for 1 Myr. Both molecular (inheritance from the parent cloud) and atomic (chemical reset) initial conditions are investigated. Results: Great diversity is observed in the relative abundance ratios of the main considered species: H2O, CO, CO2, CH4, O2, NH3 and N2. The choice of ionisation level, the choice of initial abundances, as well as the extent of chemical reaction types included are all factors that affect the chemical evolution. The only exception is the inheritance scenario with a low ionisation level, which results in negligible changes compared with the initial abundances, regardless of whether or not grain-surface chemistry is included. The grain temperature plays an important role, especially in the critical 20-28 K region where atomic H no longer sticks long enough to the surface to react, but atomic O does. Above 28 K, efficient grain-surface production of CO2 ice is seen, as well as O2 gas and ice under certain conditions, at the expense of H2O and CO. H2O ice is produced on grain surfaces only below 28 K. For high ionisation levels at intermediate disk radii, CH4 gas is

  3. Flammable gas interlock spoolpiece flow response test report

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, T.C., Fluor Daniel Hanford

    1997-03-24

    The purpose of this test report is to document the testing performed under the guidance of HNF-SD-WM-TC-073, {ital Flammable Gas Interlock Spoolpiece Flow Response Test Plan and Procedure}. This testing was performed for Lockheed Martin Hanford Characterization Projects Operations (CPO) in support of Rotary Mode Core Sampling jointly by SGN Eurisys Services Corporation and Numatec Hanford Company. The testing was conducted in the 305 building Engineering Testing Laboratory (ETL). NHC provides the engineering and technical support for the 305 ETL. The key personnel identified for the performance of this task are as follows: Test responsible engineering manager, C. E. Hanson; Flammable Gas Interlock Design Authority, G. P. Janicek; 305 ETL responsible manager, N. J. Schliebe; Cognizant RMCS exhauster engineer, E. J. Waldo/J. D. Robinson; Cognizant 305 ETL engineer, K. S. Witwer; Test director, T. C. Schneider. Other support personnel were supplied, as necessary, from 305/306 ETL. The testing, on the flammable Gas Interlock (FGI) system spoolpiece required to support Rotary Mode Core Sampling (RMCS) of single shell flammable gas watch list tanks, took place between 2-13-97 and 2-25-97.

  4. The effects of perturbations on the flammability limits

    Science.gov (United States)

    T'Ien, J. S.

    1973-01-01

    Based on the mechanism of heat losses, the known effects of external disturbances (pressure waves or turbulences) on the flammability limits are explained. This includes the sensitivity of near-limit flames to perturbations and the flame quenching by disturbances. The significance of the unstable solution as the criterion for dynamic extinction is stressed.

  5. 77 FR 62224 - Hanford Tank Farms Flammable Gas Safety Strategy

    Science.gov (United States)

    2012-10-12

    ... tanks' headspace. A significant flammable gas accident would have considerable radiological consequences... inventory of the tanks and (2) the amount of waste that could be released in a major accident...] [FR Doc No: 2012-25064] DEFENSE NUCLEAR FACILITIES SAFETY BOARD [Recommendation 2012-2] Hanford...

  6. Spruce beetle-induced changes to Engelmann spruce foliage flammability

    Science.gov (United States)

    Wesley G. Page; Michael J. Jenkins; Justin B. Runyon

    2014-01-01

    Intermountain Engelmann spruce (Picea engelmannii Parry ex Engelm) stands affected by the spruce beetle (Dendroctonus rufipennis Kirby) represent a unique and growing fuel complex. In this study, we quantified and compared the changes in moisture content, chemistry, and flammability of foliage from trees in three crown condition classes: unattacked (green [G]),...

  7. A global distribution of the ignitability component of flammability based on climatic drivers

    Science.gov (United States)

    Karali, Anna; Fyllas, Nikolaos M.; Hatzaki, Maria; Giannakopoulos, Christos; Nastos, Panagiotis

    2017-04-01

    Fire regime is the result of complex interactions among ignition, topography, weather and vegetation. Even though the influence of vegetation varies regionally, it remains the only component that can be directly managed in order to reduce the negative impacts of wildland fires. Therefore, reliable information on vegetation flammability is required, making it one of the essential components of fire risk assessment and management. Specific Leaf Area (SLA [cm2 g-1], the ratio of leaf area to leaf dry mass) has received little attention regarding its relationship with ignitability and, thus, flammability. However, recent studies on a regional scale have shown that leaves of higher SLA are more ignitable. Thus, in the framework of the current study, the ignitability, as a function of SLA on global scale, is explored. In order to calculate SLA, a linear regression model combining SLA and climate data has been used (Maire et al., 2015). The climate data used for its calculation include the maximum monthly fractional sunshine duration, the maximum monthly temperature and the number of days with daily mean temperature above 0°C for each grid cell, obtained from the ERA-Interim gridded observations database. Subsequently, the ignitability component of flammability is calculated on a global scale using a bivariate regression relationship with SLA based on experimental burns of leaf materials (Grootemaat et al., 2015). The global distribution of ignitability can subsequently be combined with fire weather index (FWI) values for the development of an integrated index of forest fire vulnerability for the current and future climate, using CMIP5 climate model outputs. This will enable the integration of functional biogeographic data with widely applied fire risk assessment methodologies at regional to global spatial scales.

  8. Advanced Borobond™ Shields for Nuclear Materials Containment and Borobond™ Immobilization of Volatile Fission Products - Final CRADA Report

    Energy Technology Data Exchange (ETDEWEB)

    Wagh, Arun S. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-05-19

    Borobond is a company-proprietary material developed by the CRADA partner in collaboration with Argonne, and is based on Argonne's Ceramicrete technology. It is being used by DOE for nuclear materials safe storage, and Boron Products, LLC is the manufacturer and supplier of Borobond.

  9. Setting the volatile composition of (exo)planet-building material. Does chemical evolution in disk midplanes matter?

    CERN Document Server

    Eistrup, Christian; van Dishoeck, Ewine F

    2016-01-01

    [Abridged] Chemical evolution in the protoplanetary disk midplane can modify the composition of ices and gases. We have investigated if and how chemical evolution affects the abundances and distributions of key volatile species in the midplane of a protoplanetary disk in the 0.2-30 AU range. A full chemical network including gas-phase, gas-grain interactions and grain-surface chemistry is used to evolve chemistry in time, for 1 Myr. Great diversity is observed in the relative abundance ratios of the main considered species: H2O, CO, CO2, CH4, O2, NH3 and N2. The choice of ionisation level, the choice of initial abundances, as well as the extent of chemical reaction types included are all factors that affect the chemical evolution. The only exception is the inheritance scenario with a low ionisation level, which results in negligible changes compared with the initial abundances, regardless of whether grain-surface chemistry is included. The chemical processing changes the C/O ratios for gas and ice significant...

  10. 16 CFR 1609.1 - Text of the Flammable Fabrics Act of 1953, as amended in 1954.

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Text of the Flammable Fabrics Act of 1953... FLAMMABLE FABRICS ACT REGULATIONS TEXT OF THE FLAMMABLE FABRICS ACT OF 1953, AS AMENDED IN 1954, PRIOR TO 1967 AMENDMENT AND REVISION § 1609.1 Text of the Flammable Fabrics Act of 1953, as amended in 1954....

  11. Effect of Meltable Triazine-DOPO Additive on Rheological, Mechanical, and Flammability Properties of PA6

    Directory of Open Access Journals (Sweden)

    Irina Butnaru

    2015-08-01

    Full Text Available Through a straightforward approach, a new meltable, halogen-free, nitrogen-phosphorus-based flame retardant (FR, 6-(2-(4,6-diamino-1,3,5-triazin-2-ylethyl dibenzo[c,e][1,2]oxaphosphinine 6-oxide (DTE-DOPO was synthesized and incorporated in polyamide 6 (PA6. It was proved that a very low phosphorus content of 1.46 wt% for DTE-DOPO additive improved the flame retardancy of PA6, leading to a non-flammable material. The performance of the new additive was compared to that of the commercially-available Exolit® OP 1230. The PA6 formulations were evaluated by measuring the rheological, mechanical, and flammability behavior. Using compounding by melt extrusion, 17 wt% additives was introduced into PA6 matrix and the corresponding formulations were characterized. The results evidenced a higher homogeneity of DTE-DOPO with PA6, a high thermal stability with a catalyzing decomposition effect on PA6 caused by the presence of the new developed FR, enhanced elasticity for the PA6/DTE-DOPO formulation and a V0 rating for both formulations. Thermal and fire analysis indicated a primary gas-phase activity, combined with a complete suppression of the self-sustained burning for the PA6/DTE-DOPO formulation.

  12. PLANETARY-SCALE STRONTIUM ISOTOPIC HETEROGENEITY AND THE AGE OF VOLATILE DEPLETION OF EARLY SOLAR SYSTEM MATERIALS

    Energy Technology Data Exchange (ETDEWEB)

    Moynier, Frederic; Podosek, Frank A. [Department of Earth and Planetary Science and McDonnell Center for Space Sciences, Washington University, St. Louis, MO 63130 (United States); Day, James M. D. [Geosciences Research Division, Scripps Institution of Oceanography, La Jolla, CA 92093-0244 (United States); Okui, Wataru; Yokoyama, Tetsuya [Department of Earth and Planetary Sciences, Tokyo Institute of Technology, Tokyo 152-8551 (Japan); Bouvier, Audrey [Department of Earth Sciences, University of Minnesota, Minneapolis, MN 55455-0231 (United States); Walker, Richard J., E-mail: moynier@levee.wustl.edu, E-mail: fap@levee.wustl.edu, E-mail: jmdday@ucsd.edu, E-mail: rjwalker@umd.edu, E-mail: okui.w.aa@m.titech.ac.jp, E-mail: tetsuya.yoko@geo.titech.ac.jp, E-mail: abouvier@umn.edu [Department of Geology, University of Maryland, College Park, MD 20742 (United States)

    2012-10-10

    Isotopic anomalies in planetary materials reflect both early solar nebular heterogeneity inherited from presolar stellar sources and processes that generated non-mass-dependent isotopic fractionations. The characterization of isotopic variations in heavy elements among early solar system materials yields important insight into the stellar environment and formation of the solar system, and about initial isotopic ratios relevant to long-term chronological applications. One such heavy element, strontium, is a central element in the geosciences due to wide application of the long-lived {sup 87}Rb-{sup 87}Sr radioactive as a chronometer. We show that the stable isotopes of Sr were heterogeneously distributed at both the mineral scale and the planetary scale in the early solar system, and also that the Sr isotopic heterogeneities correlate with mass-independent oxygen isotope variations, with only CI chondrites plotting outside of this correlation. The correlation implies that most solar system material formed by mixing of at least two isotopically distinct components: a CV-chondrite-like component and an O-chondrite-like component, and possibly a distinct CI-chondrite-like component. The heterogeneous distribution of Sr isotopes may indicate that variations in initial {sup 87}Sr/{sup 86}Sr of early solar system materials reflect isotopic heterogeneity instead of having chronological significance, as interpreted previously. For example, given the differences in {sup 84}Sr/{sup 86}Sr between calcium aluminum inclusions and eucrites ({epsilon}{sup 84}Sr > 2), the difference in age between these materials would be {approx}6 Ma shorter than previously interpreted, placing the Sr chronology in agreement with other long- and short-lived isotope systems, such as U-Pb and Mn-Cr.

  13. Development of urine standard reference materials for metabolites of organic chemicals including polycyclic aromatic hydrocarbons, phthalates, phenols, parabens, and volatile organic compounds

    Science.gov (United States)

    Schantz, Michele M.; Benner, Bruce A.; Heckert, N. Alan; Sander, Lane C.; Sharpless, Katherine E.; Vander Pol, Stacy S.; Vasquez, Y.; Villegas, M.; Wise, Stephen A.; Alwis, K. Udeni; Blount, Benjamin C.; Calafat, Antonia M.; Li, Zheng; Silva, Manori J.; Ye, Xiaoyun; Gaudreau, Éric; Patterson, Donald G.; Sjödin, Andreas

    2016-01-01

    Two new Standard Reference Materials (SRMs), SRM 3672 Organic Contaminants in Smokers’ Urine (Frozen) and SRM 3673 Organic Contaminants in Non-Smokers’ Urine (Frozen), have been developed in support of studies for assessment of human exposure to select organic environmental contaminants. Collaborations among three organizations resulted in certified values for 11 hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) and reference values for 11 phthalate metabolites, 8 environmental phenols and parabens, and 24 volatile organic compound (VOC) metabolites. Reference values are also available for creatinine and the free forms of caffeine, theobromine, ibuprofen, nicotine, cotinine, and 3-hydroxycotinine. These are the first urine Certified Reference Materials characterized for metabolites of organic environmental contaminants. Noteworthy, the mass fractions of the environmental organic contaminants in the two SRMs are within the ranges reported in population survey studies such as the National Health and Nutrition Examination Survey (NHANES) and the Canadian Health Measures Survey (CHMS). These SRMs will be useful as quality control samples for ensuring compatibility of results among population survey studies and will fill a void to assess the accuracy of analytical methods used in studies monitoring human exposure to these organic environmental contaminants. PMID:25651899

  14. Development of urine standard reference materials for metabolites of organic chemicals including polycyclic aromatic hydrocarbons, phthalates, phenols, parabens, and volatile organic compounds.

    Science.gov (United States)

    Schantz, Michele M; Benner, Bruce A; Heckert, N Alan; Sander, Lane C; Sharpless, Katherine E; Vander Pol, Stacy S; Vasquez, Y; Villegas, M; Wise, Stephen A; Alwis, K Udeni; Blount, Benjamin C; Calafat, Antonia M; Li, Zheng; Silva, Manori J; Ye, Xiaoyun; Gaudreau, Éric; Patterson, Donald G; Sjödin, Andreas

    2015-04-01

    Two new Standard Reference Materials (SRMs), SRM 3672 Organic Contaminants in Smokers' Urine (Frozen) and SRM 3673 Organic Contaminants in Non-Smokers' Urine (Frozen), have been developed in support of studies for assessment of human exposure to select organic environmental contaminants. Collaborations among three organizations resulted in certified values for 11 hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) and reference values for 11 phthalate metabolites, 8 environmental phenols and parabens, and 24 volatile organic compound (VOC) metabolites. Reference values are also available for creatinine and the free forms of caffeine, theobromine, ibuprofen, nicotine, cotinine, and 3-hydroxycotinine. These are the first urine Certified Reference Materials characterized for metabolites of organic environmental contaminants. Noteworthy, the mass fractions of the environmental organic contaminants in the two SRMs are within the ranges reported in population survey studies such as the National Health and Nutrition Examination Survey (NHANES) and the Canadian Health Measures Survey (CHMS). These SRMs will be useful as quality control samples for ensuring compatibility of results among population survey studies and will fill a void to assess the accuracy of analytical methods used in studies monitoring human exposure to these organic environmental contaminants.

  15. STEADY STATE FLAMMABLE GAS RELEASE RATE CALCULATION & LOWER FLAMMABILITY LEVEL EVALUATION FOR HANFORD TANK WASTE [SEC 1 & 2

    Energy Technology Data Exchange (ETDEWEB)

    HU, T.A.

    2003-09-30

    Flammable gases such as hydrogen, ammonia, and methane are observed in the tank dome space of the Hanford Site high-level waste tanks. This report assesses the steady-state flammability level under normal and off-normal ventilation conditions in the tank dome space for 177 double-shell tanks and single-shell tanks at the Hanford Site. The steady-state flammability level was estimated from the gas concentration of the mixture in the dome space using estimated gas release rates, Le Chatelier's rule and lower flammability limits of fuels in an air mixture. A time-dependent equation of gas concentration, which is a function of the gas release and ventilation rates in the dome space, has been developed for both soluble and insoluble gases. With this dynamic model, the time required to reach the specified flammability level at a given ventilation condition can be calculated. In the evaluation, hydrogen generation rates can be calculated for a given tank waste composition and its physical condition (e.g., waste density, waste volume, temperature, etc.) using the empirical rate equation model provided in Empirical Rate Equation Model and Rate Calculations of Hydrogen Generation for Hanford Tank Waste, HNF-3851. The release rate of other insoluble gases and the mass transport properties of the soluble gas can be derived from the observed steady-state gas concentration under normal ventilation conditions. The off-normal ventilation rate is assumed to be natural barometric breathing only. A large body of data is required to do both the hydrogen generation rate calculation and the flammability level evaluation. For tank waste that does not have sample-based data, a statistical-based value from probability distribution regression was used based on data from tanks belonging to a similar waste group. This report (Revision 3) updates the input data of hydrogen generation rates calculation for 177 tanks using the waste composition information in the Best-Basis Inventory Detail

  16. Explosion impacts during transport of hazardous cargo: GIS-based characterization of overpressure impacts and delineation of flammable zones for ammonia.

    Science.gov (United States)

    Inanloo, Bahareh; Tansel, Berrin

    2015-06-01

    The aim of this research was to investigate accidental releases of ammonia followed by an en-route incident in an attempt to further predict the consequences of hazardous cargo accidents. The air dispersion model Areal Locations of Hazardous Atmospheres (ALOHA) was employed to track the probable outcomes of a hazardous material release of a tanker truck under different explosion scenarios. The significance of identification of the flammable zones was taken into consideration; in case the flammable vapor causes an explosion. The impacted areas and the severity of the probable destructions were evaluated for an explosion by considering the overpressure waves. ALOHA in conjunction with ArcGIS was used to delineate the flammable and overpressure impact zones for different scenarios. Based on the results, flammable fumes were formed in oval shapes having a chief axis along the wind direction at the time of release. The expansions of the impact areas under the overpressure value which can lead to property damage for 2 and 20 tons releases, under very stable and unstable atmospheric conditions were estimated to be around 1708, 1206; 3742, 3527 feet, respectively, toward the wind direction. A sensitivity analysis was done to assess the significance of wind speed on the impact zones. The insight provided by this study can be utilized by decision makers in transportation of hazardous materials as a guide for possible rerouting, rescheduling, or limiting the quantity of hazardous cargo to reduce the possible impacts after hazardous cargo accidents during transport.

  17. Evaluation of 241 AN tank farm flammable gas behavior

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, D.A.

    1994-01-01

    The 241 AN Tank Farm tanks 241-AN-103, -104, and 105 are Flammable Gas Watch List tanks. Characteristics exhibited by these tanks (i.e., surface level drops, pressure increases, and temperature profiles) are similar to those exhibited by tank 241-SY-101, which is also a Watch List tank. Although the characteristics exhibited by tank 241-SY-101 are also present in tanks 241-AN-103, -104, and 105, they are exhibited to a lesser degree in the AN Tank Farm tanks. The 241 AN Tank Farm tanks have only small surface level drops, and the pressure changes that occur are not sufficient to release an amount of gas that would cause the dome space to exceed the lower flammability limit (LFL) for hydrogen. Therefore, additional restrictions are probably unnecessary for working within the 241 AN Tank Farm, either within the dome space of the tanks or in the waste.

  18. Flammability Properties of Composites of Wood Fiber and Recycled Plastic

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Flammability properties of composites of wood fiber and recycled plastic were evaluated by the cone calorimeter and oxygen index chamber. Results were shown as follows: 1) Wood-PVC composite showed worse thermal stability on time to ignition (TTI) and mean heat release rate (MHRR), but better performance on heat release rate (HRR) and mean efficient heat of combustion (MEHC); wood-PP composite had better thermal stability properties, but was worse on other fire performance; 2) Compared with wood-PVC composi...

  19. Retained Gas Sampling Results for the Flammable Gas Program

    Energy Technology Data Exchange (ETDEWEB)

    J.M. Bates; L.A. Mahoney; M.E. Dahl; Z.I. Antoniak

    1999-11-18

    The key phenomena of the Flammable Gas Safety Issue are generation of the gas mixture, the modes of gas retention, and the mechanisms causing release of the gas. An understanding of the mechanisms of these processes is required for final resolution of the safety issue. Central to understanding is gathering information from such sources as historical records, tank sampling data, tank process data (temperatures, ventilation rates, etc.), and laboratory evaluations conducted on tank waste samples.

  20. Off-site ignition probability of flammable gases.

    Science.gov (United States)

    Rew, P J; Spencer, H; Daycock, J

    2000-01-07

    A key step in the assessment of risk for installations where flammable liquids or gases are stored is the estimation of ignition probability. A review of current modelling and data confirmed that ignition probability values used in risk analyses tend to be based on extrapolation of limited incident data or, in many cases, on the judgement of those conducting the safety assessment. Existing models tend to assume that ignition probability is a function of release rate (or flammable gas cloud size) alone and they do not consider location, density or type of ignition source. An alternative mathematical framework for calculating ignition probability is outlined in which the approach used is to model the distribution of likely ignition sources and to calculate ignition probability by considering whether the flammable gas cloud will reach these sources. Data are collated on the properties of ignition sources within three generic land-use types: industrial, urban and rural. These data are then incorporated into a working model for ignition probability in a form capable of being implemented within risk analysis models. The sensitivity of the model results to assumptions made in deriving the ignition source properties is discussed and the model is compared with other available ignition probability methods.

  1. Flammability Limits of Gases Under Low Gravity Conditions

    Science.gov (United States)

    Strehlow, R. A.

    1985-01-01

    The purpose of this combustion science investigation is to determine the effect of zero, fractional, and super gravity on the flammability limits of a premixed methane air flame in a standard 51 mm diameter flammability tube and to determine, if possible, the fluid flow associated with flame passage under zero-g conditions and the density (and hence, temperature) profiles associated with the flame under conditions of incipient extinction. This is accomplished by constructing an appropriate apparatus for placement in NASA's Lewis Research Center Lear Jet facility and flying the prescribed g-trajectories while the experiment is being performed. Data is recorded photographically using the visible light of the flame. The data acquired is: (1) the shape and propagation velocity of the flame under various g-conditions for methane compositions that are inside the flammable limits, and (2) the effect of gravity on the limits. Real time accelerometer readings for the three orthogonal directions are displayed in full view of the cameras and the framing rate of the cameras is used to measure velocities.

  2. Hazard assessments of double-shell flammable gas tanks

    Energy Technology Data Exchange (ETDEWEB)

    Fox, G.L.; Stepnewski, D.D.

    1994-09-28

    This report is the fourth in a series of hazard assessments performed on the double-shell flammable gas watch list tanks. This report focuses on hazards associated with the double-shell watch list tanks (101-AW, 103-AN, 104-AN, and 105-AN). While a similar assessment has already been performed for tank 103-SY, it is also included here to incorporate a more representative slurry gas mixture and provide a consistent basis for comparing results for all the flammable gas tanks. This report is intended to provide an in-depth assessment by considering the details of the gas release event and slurry gas mixing as the gas is released from the waste. The consequences of postulated gas ignition are evaluated using a plume burn model and updated ignition frequency predictions. Tank pressurization which results from a gas burn, along with the structural response, is also considered. The report is intended to support the safety basis for work activities in flammable gas tanks by showing margins to safety limits that are available in the design and procedures.

  3. 29 CFR 1915.36 - Flammable liquids.

    Science.gov (United States)

    2010-07-01

    ... concentration. (3) Scrapings and rags soaked with these materials shall be kept in a covered metal container. (4..., shall be used. (5) A competent person shall inspect all power and lighting cables to ensure that the insulation is in excellent condition, free of all cracks and worn spots, that there are no connections...

  4. Hydrodistillation-adsorption method for the isolation of water-soluble, non-soluble and high volatile compounds from plant materials.

    Science.gov (United States)

    Mastelić, J; Jerković, I; Blazević, I; Radonić, A; Krstulović, L

    2008-08-15

    Proposed method of hydrodistillation-adsorption (HDA) on activated carbon and hydrodistillation (HD) with solvent trap were compared for the isolation of water-soluble, non-soluble and high volatile compounds, such as acids, monoterpenes, isothiocyanates and others from carob (Certonia siliqua L.), rosemary (Rosmarinus officinalis L.) and rocket (Eruca sativa L.). Isolated volatiles were analyzed by GC and GC/MS. The main advantages of HDA method over ubiquitous HD method were higher yields of volatile compounds and their simultaneous separation in three fractions that enabled more detail analyses. This method is particularly suitable for the isolation and analysis of the plant volatiles with high amounts of water-soluble compounds. In distinction from previously published adsorption of remaining volatile compounds from distillation water on activated carbon, this method offers simultaneous hydrodistillation and adsorption in the same apparatus.

  5. Litter flammability of French Mediterranean vegetation types : a cross-substratum analysis

    OpenAIRE

    Curt, T.; Schaffhauser, A.; Borgniet, L.; Esteve, R.; Ganteaume, A.; Jappiot, M.; Lampin-Maillet, C.; Martin, W.; N'Diaye, A

    2010-01-01

    International audience; Assessing the flammability of litters in fire-prone ecosystems of major importance to quantify the wildland fire hazard. We compared undisturbed litter samples typical of French ecosystems on the two main types of substratum, i.e. acidic versus limestone, to investigate to which extent their characteristics and flammability may differ. We measured in the laboratory several flammability parameters on oven-dried samples that mimic the high fire hazard level in summer. On...

  6. Flammability Testing of Fabrics Treated with Oil-Based Shear Thickening Fluids

    Science.gov (United States)

    2014-05-01

    thickening fluid (STF) are evaluated under flammability testing. The tested fabrics include a woven cotton-nylon blend, a woven Kevlar textile, and a...hybrid ultrahigh molecular weight polyethylene (UHMWPE) – Kevlar felt. The oil-based STF is a colloid of silica nanoparticles in a paraffin oil. Test...enhanced flammability resistance. 15. SUBJECT TERMS shear thickening fluid, Kevlar , flammability 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF

  7. Effect of organic fertilizers prepared from organic waste materials on the production of antibacterial volatile organic compounds by two biocontrol Bacillus amyloliquefaciens strains.

    Science.gov (United States)

    Raza, Waseem; Wei, Zhong; Ling, Ning; Huang, Qiwei; Shen, Qirong

    2016-06-10

    Three organic fertilizers made of different animal and plant waste materials (BOFs) were evaluated for their effects on the production of antibacterial volatile organic compounds (VOCs) by two Bacillus amyloliquefaciens strains SQR-9 and T-5 against the tomato wilt pathogen Ralstonia solanacearum (RS). Both strains could produce VOCs that inhibited the growth and virulence traits of RS; however, in the presence of BOFs, the production of antibacterial VOCs was significantly increased. The maximum inhibition of growth and virulence traits of RS by VOCs of T-5 and SQR-9 was determined at 1.5% BOF2 and 2% BOF3, respectively. In case of strain T-5, 2-nonanone, nonanal, xylene, benzothiazole, and butylated hydroxy toluene and in case of strain SQR-9, 2-nonanone, nonanal, xylene and 2-undecanone were the main antibacterial VOCs whose production was increased in the presence of BOFs. The results of this study reveal another significance of using organic fertilizers to improve the antagonistic activity of biocontrol agents against phytopathogens.

  8. Pricing Volatility Referenced Assets

    Directory of Open Access Journals (Sweden)

    Alan De Genaro Dario

    2006-12-01

    Full Text Available Volatility swaps are contingent claims on future realized volatility. Variance swaps are similar instruments on future realized variance, the square of future realized volatility. Unlike a plain vanilla option, whose volatility exposure is contaminated by its asset price dependence, volatility and variance swaps provide a pure exposure to volatility alone. This article discusses the risk-neutral valuation of volatility and variance swaps based on the framework outlined in the Heston (1993 stochastic volatility model. Additionally, the Heston (1993 model is calibrated for foreign currency options traded at BMF and its parameters are used to price swaps on volatility and variance of the BRL / USD exchange rate.

  9. Upward Flame Propagation and Wire Insulation Flammability: 2006 Round Robin Data Analysis

    Science.gov (United States)

    Hirsch, David B.

    2007-01-01

    This viewgraph document reviews test results from tests of different material used for wire insulation for flame propagation and flammability. The presentation focused on investigating data variability both within and between laboratories; evaluated the between-laboratory consistency through consistency statistic h, which indicates how one laboratory s cell average compares with averages from other labs; evaluated the within-laboratory consistency through the consistency statistic k, which is an indicator of how one laboratory s within-laboratory variability compares with the variability of other labs combined; and extreme results were tested to determine whether they resulted by chance or from nonrandom causes (human error, instrument calibration shift, non-adherence to procedures, etc.)

  10. Origin of Volatiles in Earth: Indigenous Versus Exogenous Sources Based on Highly Siderophile, Volatile Siderophile, and Light Volatile Elements

    Science.gov (United States)

    Righter, K.; Danielson, L.; Pando, K. M.; Marin, N.; Nickodem, K.

    2015-01-01

    Origin of Earth's volatiles has traditionally been ascribed to late accretion of material after major differentiation events - chondrites, comets, ice or other exogenous sources. A competing theory is that the Earth accreted its volatiles as it was built, thus water and other building blocks were present early and during differentiation and core formation (indigenous). Here we discuss geochemical evidence from three groups of elements that suggests Earth's volatiles were acquired during accretion and did not require additional sources after differentiation.

  11. Volatile accretion history of the Earth.

    Science.gov (United States)

    Wood, B J; Halliday, A N; Rehkämper, M

    2010-10-28

    It has long been thought that the Earth had a protracted and complex history of volatile accretion and loss. Albarède paints a different picture, proposing that the Earth first formed as a dry planet which, like the Moon, was devoid of volatile constituents. He suggests that the Earth's complement of volatile elements was only established later, by the addition of a small veneer of volatile-rich material at ∼100 Myr (here and elsewhere, ages are relative to the origin of the Solar System). Here we argue that the Earth's mass balance of moderately volatile elements is inconsistent with Albarède's hypothesis but is well explained by the standard model of accretion from partially volatile-depleted material, accompanied by core formation.

  12. Outlier treatment for improving parameter estimation of group contribution based models for upper flammability limit

    DEFF Research Database (Denmark)

    Frutiger, Jerome; Abildskov, Jens; Sin, Gürkan

    2015-01-01

    Flammability data is needed to assess the risk of fire and explosions. This study presents a new group contribution (GC) model to predict the upper flammability limit UFL oforganic chemicals. Furthermore, it provides a systematic method for outlier treatment inorder to improve the parameter...

  13. Differences in leaf flammability, leaf traits and flammability-trait relationships between native and exotic plant species of dry sclerophyll forest.

    Science.gov (United States)

    Murray, Brad R; Hardstaff, Lyndle K; Phillips, Megan L

    2013-01-01

    The flammability of plant leaves influences the spread of fire through vegetation. Exotic plants invading native vegetation may increase the spread of bushfires if their leaves are more flammable than native leaves. We compared fresh-leaf and dry-leaf flammability (time to ignition) between 52 native and 27 exotic plant species inhabiting dry sclerophyll forest. We found that mean time to ignition was significantly faster in dry exotic leaves than in dry native leaves. There was no significant native-exotic difference in mean time to ignition for fresh leaves. The significantly higher fresh-leaf water content that was found in exotics, lost in the conversion from a fresh to dry state, suggests that leaf water provides an important buffering effect that leads to equivalent mean time to ignition in fresh exotic and native leaves. Exotic leaves were also significantly wider, longer and broader in area with significantly higher specific leaf area-but not thicker-than native leaves. We examined scaling relationships between leaf flammability and leaf size (leaf width, length, area, specific leaf area and thickness). While exotics occupied the comparatively larger and more flammable end of the leaf size-flammability spectrum in general, leaf flammability was significantly correlated with all measures of leaf size except leaf thickness in both native and exotic species such that larger leaves were faster to ignite. Our findings for increased flammability linked with larger leaf size in exotics demonstrate that exotic plant species have the potential to increase the spread of bushfires in dry sclerophyll forest.

  14. Differences in leaf flammability, leaf traits and flammability-trait relationships between native and exotic plant species of dry sclerophyll forest.

    Directory of Open Access Journals (Sweden)

    Brad R Murray

    Full Text Available The flammability of plant leaves influences the spread of fire through vegetation. Exotic plants invading native vegetation may increase the spread of bushfires if their leaves are more flammable than native leaves. We compared fresh-leaf and dry-leaf flammability (time to ignition between 52 native and 27 exotic plant species inhabiting dry sclerophyll forest. We found that mean time to ignition was significantly faster in dry exotic leaves than in dry native leaves. There was no significant native-exotic difference in mean time to ignition for fresh leaves. The significantly higher fresh-leaf water content that was found in exotics, lost in the conversion from a fresh to dry state, suggests that leaf water provides an important buffering effect that leads to equivalent mean time to ignition in fresh exotic and native leaves. Exotic leaves were also significantly wider, longer and broader in area with significantly higher specific leaf area-but not thicker-than native leaves. We examined scaling relationships between leaf flammability and leaf size (leaf width, length, area, specific leaf area and thickness. While exotics occupied the comparatively larger and more flammable end of the leaf size-flammability spectrum in general, leaf flammability was significantly correlated with all measures of leaf size except leaf thickness in both native and exotic species such that larger leaves were faster to ignite. Our findings for increased flammability linked with larger leaf size in exotics demonstrate that exotic plant species have the potential to increase the spread of bushfires in dry sclerophyll forest.

  15. Novel Scintillating Materials Based on Phenyl-Polysiloxane for Neutron Detection and Monitoring

    CERN Document Server

    Degerlier, M; Gramegna, F; Marchi, T; Palma, M Dalla; Cinausero, M; Maggioni, G; Quaranta, A; Collazuol, G; Bermudez, J

    2013-01-01

    Neutron detectors are extensively used at many nuclear research facilities across Europe. Their application range covers many topics in basic and applied nuclear research: in nuclear structure and reaction dynamics (reaction reconstruction and decay studies); in nuclear astrophysics (neutron emission probabilities); in nuclear technology (nuclear data measurements and in-core/off-core monitors); in nuclear medicine (radiation monitors, dosimeters); in materials science (neutron imaging techniques); in homeland security applications (fissile materials investigation and cargo inspection). Liquid scintillators, widely used at present, have however some drawbacks given by toxicity, flammability, volatility and sensitivity to oxygen that limit their duration and quality. Even plastic scintillators are not satisfactory because they have low radiation hardness and low thermal stability. Moreover organic solvents may affect their optical properties due to crazing. In order to overcome these problems, phenyl-polysilox...

  16. Properties and flammability of major tree species in the Beijing area

    Institute of Scientific and Technical Information of China (English)

    Xiaoli WANG; Shukui NIU; Zhenguo KAN

    2009-01-01

    In order to examine correlations among the properties of tree species and to quantify the relationships between these properties and flammability, the properties of 20 tree species, consisting of heat of combustion, extractive contents, ash content, moisture content and basic density, were measured via experimental methods. In the first instance, the results show that, there are significant correlations between heat of combustion and extractive contents, ash content and basic density. Second, heat of combustion can be presented effectively in terms of linear regression models with extractive contents and ash content as independent variables. Third, a flammable model was developed based on four properties of tree species as independent variables, i.e., heat of combustion, extractive contents, ash content and moisture content. Finally, the flammability of 20 tree species is compared, ordered and ranked based on this flammable model. The conclusion is that flammability can be predicted from properties of tree species, which are significantly correlated among themselves.

  17. Methods development for measuring and classifying flammability/combustibility of refrigerants. Interim report, task 2 - test plan

    Energy Technology Data Exchange (ETDEWEB)

    Heinonen, E.W.; Tapscott, R.E. [Univ. of New Mexico, Albuquerque, NM (United States)

    1994-07-01

    Regulations on alternative refrigerants and concerns for the environment are forcing the refrigeration industry to consider the use of potentially flammable fluids to replace CFC fluids currently in use. The objectives of this program are to establish the conditions under which refrigerants and refrigerant blends exhibit flammability and to develop appropriate methods to measure flammability.

  18. 16 CFR 1145.3 - Extremely flammable contact adhesives; risk of burns from explosive vapor ignition and flashback...

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Extremely flammable contact adhesives; risk... TO OTHER ACTS UNDER THE CONSUMER PRODUCT SAFETY ACT § 1145.3 Extremely flammable contact adhesives... associated with certain extremely flammable contact adhesives under the Consumer Product Safety Act...

  19. 46 CFR 35.30-40 - Flammable liquid and gas fuels as ship's stores-TB/ALL.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Flammable liquid and gas fuels as ship's stores-TB/ALL... OPERATIONS General Safety Rules § 35.30-40 Flammable liquid and gas fuels as ship's stores—TB/ALL. Flammable liquids and gases other than diesel fuel, to be used as fuel for approved equipment must satisfy...

  20. Flammability Tests on Hot Surface for Several Hydraulic Fluids

    Directory of Open Access Journals (Sweden)

    L. Deleanu

    2011-09-01

    Full Text Available Industrial equipment using hydraulic fluids are design to accept higher load and speed, implicitly higher temperatures, including for fluids. Leakages from enclosures like gear boxes or hydraulic systems could increase the risk of fluid reaching hot surfaces, thus producing fires hard to be controlled and isolated. The designer have to evaluate the flammability of fluids and they should select several solutions for a particular application in order to estimate the costs of different solutions and to mitigate the risk of having accidental fires due to a specific fluid grade. The tests were done with the help of an original equipment allowing a dedicated soft assistance in order to protect the operator and to sustain reproducibility, according to the standard SR EN ISO 20823:2004 Petroleum and related products. The determination of the flammability characteristics of fluids in contact with hot surfaces - Manifold ignition test, There were tested the following grades of hydraulic oil HLP 68 X-Oil, HFC Prista, MHE 40 Prista (100% oil, a rapeseed oil (obtained after a dewaxing process and an emulsion oil-in-water (5% vol. MHE 40 Prista. There were identified distinct behaviours of these fluids under the test conditions

  1. Influence of Knits Structure on Flammability and Comfortability

    Directory of Open Access Journals (Sweden)

    Mikučionienė D.

    2014-12-01

    Full Text Available Investigations of the influence of the knit structure, i.e. the loop length and the number of yarns in a loop, on flammability and comfortability are presented in this paper. The investigations were carried out using single jersey knits from Delta TA 18 tex × 2 yarns with five variants of a loop length. Single yarn as well as folded yarn from two single yarns was used in the investigations. Comparison of the results of single-layer knits flammability and air permeability with those of multilayer packet was made. The results obtained show that an increase in the loop length of the knit increases their permeability to air and decreases the burning time as well as increase in the number of layers decreases the air permeability and increases the burning time. Moreover, the similar burning time with significantly different permeability to air can be achieved changing the basic knitting parameters, i.e. the loop length and/or the yarn linear density.

  2. Learning Equipment for the Flammability Limits of Liquefied Petroleum Gas

    Directory of Open Access Journals (Sweden)

    Siriratchanee Sirisawat

    2012-01-01

    Full Text Available Problem statement: This article was developing learning equipment for flammability limit behavior which designed for study the relation of Liquefied Petroleum Gas (LPG and combustion. The equipment can be use as an instructional media for obviously experiment of combustion. Approach: The test chamber was designed by using the stainless as a structure. The mirror with safety film was used for safety purpose to the tester. The mirror was the additional equipment for the ignition vision. The size of test chamber was 40×25×20 cm. The top of chamber can be opened when the ignition was occurred to reduce the inner pressure that can break the mirror or can be a cause of damage to other parts. The 2 of stainless plates with the size of 15×40 cm. were used and the hinges were attached at the upper edges of the chamber from both sides. The metal was closely attached at the chamber edge to reduce the leak of fuel to outer environment. The bottom structure of the chamber installs the control mainboard of electronics system and motor. The control of heat gain system inside the heat chamber. Results: The test chamber is designed to demonstrate the ignition. So, the size has to be suitably designed and large enough for convenience in monitoring. It can be seen that when the test is conducted in a real system, the result is extremely differed from the theory. The reason is the experimentation by the theory using the cup burner or a cylindrical glass cup. This cup has an outside diameter of 28 mm. and around the cup tunnel has an inside diameter of 8.5 or 9.5 cm with 53.5 cm. of height. The ratios of both testing equipments are extremely differed, so there is an opportunity that the accuracy is highly shifted. Conclusion: The test chamber shows that the flammability limit of LPG vary with temperature and can be compare with burgess-wheeler law. This law mentioned “LFL and UFL is relative with the chemical in Paraffin Hydrocarbon (Alkane Group in

  3. Flammability across the gymnosperm phylogeny: the importance of litter particle size.

    Science.gov (United States)

    Cornwell, William K; Elvira, Alba; van Kempen, Lute; van Logtestijn, Richard S P; Aptroot, André; Cornelissen, J Hans C

    2015-04-01

    Fire is important to climate, element cycles and plant communities, with many fires spreading via surface litter. The influence of species on the spread of surface fire is mediated by their traits which, after senescence and abscission, have 'afterlife' effects on litter flammability. We hypothesized that differences in litter flammability among gymnosperms are determined by litter particle size effects on litterbed packing. We performed a mesocosm fire experiment comparing 39 phylogenetically wide-ranging gymnosperms, followed by litter size and shape manipulations on two chemically contrasting species, to isolate the underlying mechanism. The first-order control on litter flammability was, indeed, litter particle size in both experiments. Most gymnosperms were highly flammable, but a prominent exception was the non-Pinus Pinaceae, in which small leaves abscised singly produced dense, non-flammable litterbeds. There are two important implications: first, ecosystems dominated by gymnosperms that drop small leaves separately will develop dense litter layers, which will be less prone to and inhibit the spread of surface litter fire. Second, some of the needle-leaved species previously considered to be flammable in single-leaf experiments were among the least flammable in litter fuel beds, highlighting the role of the litter traits of species in affecting surface fire regimes.

  4. Species composition and fire: non-additive mixture effects on ground fuel flammability

    Directory of Open Access Journals (Sweden)

    Cassandra eVan Altena

    2012-04-01

    Full Text Available Biodiversity effects on many aspects of ecosystem function have been well documented. However, fire is an exception: fire experiments have mainly included single species, bulk litter, or vegetation, and, as such, the role of biodiversity as a determinant of flammability, a crucial aspect of ecosystem function, is poorly understood. This study is the first to experimentally test whether flammability characteristics of two-species mixtures are non-additive, i.e. differ from expected flammability based on the component species in monoculture. In standardized fire experiments on ground fuels, including monocultures and mixtures of five contrasting subarctic plant fuel types in a controlled laboratory environment, we measured flame speed, flame duration and maximum temperature. Broadly half of the mixture combinations showed non-additive effects for these flammability indicators; these were mainly enhanced dominance effects, where the fuel types with the more flammable value for a characteristic determined the flammability of the whole mixture. The high incidence of species non-additive effects on ground fuel flammability suggest that the combinations of fuel types may have important effects on ground fire regimes in vegetations differing or changing in species composition.

  5. Lean flammability limit of downward propagating hydrogen-air flames

    Science.gov (United States)

    Patnaik, G.; Kailasanath, K.

    1992-01-01

    Detailed multidimensional numerical simulations that include the effects of wall heat losses have been performed to study the dynamics of downward flame propagation and extinguishment in lean hydrogen-air mixtures. The computational results show that a downward propagating flame in an isothermal channel has a flammability limit of around 9.75 percent. This is in excellent agreement with experimental results. Also in excellent agreement are the detailed observations of the flame behavior at the point of extinguishment. The primary conclusion of this work is that detailed numerical simulations that include wall heat losses and the effect of gravity can adequately simulate the dynamics of the extinguishment process in downward-propagating hydrogen-air flames. These simulations can be examined in detail to gain understanding of the actual extinction process.

  6. Flammable gas tank waste level reconcilliation for 241-SX-102

    Energy Technology Data Exchange (ETDEWEB)

    Brevick, C.H.; Gaddie, L.A.

    1997-06-23

    Fluoro Dynel Northwest (FDNW) was authorized to address flammable gas issues by reconciling the unexplained surface level increases in Tank 24 1-S-1 1 1 (S-I 1 1, typical). The trapped gas evaluation document (ref 1) states that Tank SX-102 exceeds the 25% of the lower flammable limit (FL) criterion (ref 2), based on a surface level rise evaluation. The Waste Storage Tank Status and Leak Detection Criteria document, commonly referred to as the ``Wallet Report`` is the basis for this letter report (ref 3). The Wallet Report is also a part of the trapped gas evaluation document criteria. The Wallet Report contains various tank information, including: physical information, status, levels, and dry wells, see Appendix A. The unexplained waste level rises were attributed to the production and retention of gas in the column of waste corresponding to the unacquainted for surface level rise. From 1973 through 1980, the Wallet Report tracked Tank S- 102 transfers and reported a net cumulative change of 19.95 in. This surface level increase is from an unknown source or is unacquainted for. Duke Engineering and Services Hanford (DASH) and Leached Martin Hanford Corporation (LMHC) are interested in determining the validity of the unexplained surface level changes reported in the 0611e Wallet Report based upon other corroborative sources of data. The purpose of this letter report is to assemble detailed surface level and waste addition data from daily tank records, logbooks, and other corroborative data that indicate surface levels, and to reconcile the cumulative unacquainted for surface level changes as shown in the Wallet Report from 1973 through 1980.

  7. Self-Flammability of Gases Generated by Hanford Tank Waste and the Potential of Nitrogen Inerting to Eliminate Flammability Safety Concerns

    Energy Technology Data Exchange (ETDEWEB)

    Mahoney, Lenna A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-10-12

    Through radiolytic and thermolytic reactions, Hanford tank wastes generate and retain a variety of gases, including hydrogen, nitrous oxide, methane (and other hydrocarbons), ammonia, and nitrogen. This gas generation can be expected to continue during processing in the Hanford Tank Waste Treatment and Immobilization Plant (WTP). The generation rates in the WTP will change from those for the in-situ tank waste because of different process temperatures, different dose rates produced by in-process changes in the proportions of solid and liquid, and dilution of the waste liquid. The flammability of the generated gas that is continuously released, and of any retained gas that might be released into a vessel headspace in quantity due to a spontaneous release, depends on the concentrations not only of the fuel gases—primarily hydrogen (H2), methane, other hydrocarbons, and ammonia—but of the oxidizer nitrous oxide (N2O). As a result of high concentrations of N2O, some gas mixtures are “self-flammable” (i.e., ignition can occur when no air is present because N2O provides the only oxidizer needed). Self-flammability could potentially reduce the effectiveness of using a nitrogen (N2) purge in the headspace as a flammability control, if its effects are not accounted for. A given amount of inertant gas (N2) can accommodate only a certain amount of a generated self-flammable gas before the mixture with inertant gas becomes flammable.

  8. A quantitative structure- property relationship of gas chromatographic/mass spectrometric retention data of 85 volatile organic compounds as air pollutant materials by multivariate methods

    Directory of Open Access Journals (Sweden)

    Sarkhosh Maryam

    2012-05-01

    Full Text Available Abstract A quantitative structure-property relationship (QSPR study is suggested for the prediction of retention times of volatile organic compounds. Various kinds of molecular descriptors were calculated to represent the molecular structure of compounds. Modeling of retention times of these compounds as a function of the theoretically derived descriptors was established by multiple linear regression (MLR and artificial neural network (ANN. The stepwise regression was used for the selection of the variables which gives the best-fitted models. After variable selection ANN, MLR methods were used with leave-one-out cross validation for building the regression models. The prediction results are in very good agreement with the experimental values. MLR as the linear regression method shows good ability in the prediction of the retention times of the prediction set. This provided a new and effective method for predicting the chromatography retention index for the volatile organic compounds.

  9. Volatile Organic Compounds (VOCs)

    Science.gov (United States)

    ... Contact Us Share Volatile Organic Compounds' Impact on Indoor Air Quality On this page: Introduction Sources Health Effects Levels in Homes Steps to Reduce Exposure Standards or Guidelines Additional Resources Introduction Volatile organic compounds ( ...

  10. Calculated flame temperature (CFT) modeling of fuel mixture lower flammability limits.

    Science.gov (United States)

    Zhao, Fuman; Rogers, William J; Mannan, M Sam

    2010-02-15

    Heat loss can affect experimental flammability limits, and it becomes indispensable to quantify flammability limits when apparatus quenching effect becomes significant. In this research, the lower flammability limits of binary hydrocarbon mixtures are predicted using calculated flame temperature (CFT) modeling, which is based on the principle of energy conservation. Specifically, the hydrocarbon mixture lower flammability limit is quantitatively correlated to its final flame temperature at non-adiabatic conditions. The modeling predictions are compared with experimental observations to verify the validity of CFT modeling, and the minor deviations between them indicated that CFT modeling can represent experimental measurements very well. Moreover, the CFT modeling results and Le Chatelier's Law predictions are also compared, and the agreement between them indicates that CFT modeling provides a theoretical justification for the Le Chatelier's Law.

  11. 49 CFR 175.310 - Transportation of flammable liquid fuel; aircraft only means of transportation.

    Science.gov (United States)

    2010-10-01

    ... impracticable. The stowage requirements of § 175.75(a) do not apply to a person operating an aircraft under the... racks or slings. (c) Flammable liquid fuels may be carried on a cargo aircraft, subject to the...

  12. Non-Flammable Crew Clothing Utilizing Phosphorus-Based Fire Retardant Polymers Project

    Data.gov (United States)

    National Aeronautics and Space Administration — For maintaining U.S. leadership role in space exploration, there is an urgent need to develop non-flammable shirts, shorts, sweaters, and jackets without...

  13. Effect of Inhibitors on Biogas Laminar Burning Velocity and Flammability Limits in Spark Ignited Premix Combustion

    Directory of Open Access Journals (Sweden)

    Willyanto Anggono

    2014-01-01

    Full Text Available Biogas is the natural byproduct of the decomposition of vegetation or animal manure, of which there are almost in exhaustable supplies in the world, and which does not contribute CO2 or other greenhouse gases to global warming or climate change. Biogas contains 66.4% flammable gas (CH4 and 33.6% inhibitors (CO2 and N2. This study focuses on the effects of inhibitors on biogas laminar burning velocity and flammability limits in spark ignited premix combustion. Spherically expanding laminar premixed flames, freely propagating from spark ignition sources in initially quiescent biogas–air mixtures, are continuously recorded by a high-speed digital camera. Initially, all the experiments in this paper were performed using inhibitorless biogas (biogas without inhibitors at room temperature, at reduced pressure (0.5 atm and at various equivalence ratios (ϕ from the lower flammable limit to the upper flammable limit. The results are compared with those from biogas (containing inhibitors flames at reduced pressure, inhibitorless biogas flames at atmospheric pressure (1 atm, and biogas flames at atmospheric pressure to emphasize the effect of inhibitors on biogas laminar burning velocity and flammability limits. Compared to an inhibitorless biogas-air mixtures, in the biogas-air mixtures, the presence of inhibitors cause a reduction in the laminar burning velocity and the flammable limits become narrower.

  14. Clothing Flammability and Burn Injuries: Public Opinion Concerning an Overlooked, Preventable Public Health Problem.

    Science.gov (United States)

    Frattaroli, Shannon; Spivak, Steven M; Pollack, Keshia M; Gielen, Andrea C; Salomon, Michele; Damant, Gordon H

    2016-01-01

    The objective of this study was to describe knowledge of clothing flammability risk, public support for clothing flammability warning labels, and stronger regulation to reduce the risk. As part of a national survey of homeowners about residential sprinkler systems, the authors included questions about clothing flammability. The authors used an online web panel to sample homeowners and descriptive methods to analyze the resulting data. The sample included 2333 homeowners. Knowledge of clothing flammability and government oversight of clothing flammability risk was low. Homeowners were evenly split about the effectiveness of current standards; however, when presented with clothing-related burn injury and death data, a majority (53%) supported stricter standards. Most homeowners (64%) supported warning labels and indicated that such labels would either have no effect on their purchasing decisions (64%) or be an incentive (24%) to purchase an item. Owners of sprinkler-equipped homes were more likely to support these interventions than owners of homes without sprinkler systems. Public knowledge about clothing flammability risks is low. Most homeowners supported clothing labels to inform consumers of this risk and increased government intervention to reduce the risk.

  15. Flammable gas issues in double-contained receiver tanks. Revision 2

    Energy Technology Data Exchange (ETDEWEB)

    Peurrung, L.M.; Mahoney, L.A.; Stewart, C.W.; Gauglitz, P.A.; Pederson, L.R.; Bryan, S.A.; Shepard, C.L.

    1998-08-01

    Four double-contained receiver tanks (DCRTs) at Hanford will be used to store salt-well pumped liquids from tanks on the Flammable Gas Watch List. This document was created to serve as a reference document describing the current knowledge of flammable gas issues in DCRTs. The document identifies, describes, evaluates, and attempts to quantify potential gas carryover and release mechanisms. It estimates several key parameters needed for these calculations, such as initial aqueous concentrations and ventilation rate, and evaluates the uncertainty in those estimates. It justifies the use of the Schumpe model for estimating vapor-liquid equilibrium constants. It identifies several potential waste compatibility issues (such as mixing and pH or temperature changes) that could lead to gas release and provides a basis for calculating their effects. It evaluates the potential for gas retention in precipitated solids within a DCRT and whether retention could lead to a buoyant displacement instability (rollover) event. It discusses rates of radiolytic, thermal, and corrosive hydrogen generation within the DCRT. It also describes in detail the accepted method of calculating the lower flammability limit (LFL) for mixtures of flammable gases. The report incorporates these analyses into two models for calculating headspace flammability, one based on instantaneous equilibrium between dissolved gases and the headspace and one incorporating limited release rates based on mass-transfer considerations. Finally, it demonstrates the use of both models to estimate headspace flammable gas concentrations and minimum ventilation rates required to maintain concentrations below 25% of the LFL.

  16. Microgravity Flammability of PMMA Rods in Concurrent Flow

    Science.gov (United States)

    Olson, Sandra L.; Ferkul, Paul V.

    2015-01-01

    Microgravity experiments burning cast PMMA cylindrical rods in axial flow have been conducted aboard the International Space Station in the Microgravity Science Glovebox (MSG) facility using the Burning and Suppression of Solids (BASS) flow duct, as part of the BASS-II experiment. Twenty-four concurrent-flow tests were performed, focusing on finding flammability limits as a function of oxygen and flow speed. The oxygen was varied by using gaseous nitrogen to vitiate the working volume of the MSG. The speed of the flow parallel to the rod was varied using a fan at the entrance to the duct. Both blowoff and quenching limits were obtained at several oxygen concentrations. Each experiment ignited the rod at the initially hemispherical stagnation tip of the rod, and allowed the flame to develop and heat the rod at a sufficient flow to sustain burning. For blowoff limit tests, the astronaut quickly turned up the flow to obtain extinction. Complementary 5.18-second Zero Gravity Facility drop tests were conducted to compare blowoff limits in short and long duration microgravity. For quenching tests, the flow was incrementally turned down and the flame allowed to stabilize at the new flow condition for at least the solid-phase response time before changing it again. Quenching was observed when the flow became sufficiently weak that the flame could no longer provide adequate heat flux to compensate for the heat losses (conduction into the rod and radiation). A surface energy balance is presented that shows the surface radiative loss exceeds the conductive loss into the rod near the limit. The flammability boundary is shown to represent a critical Damkohler number, expressed in terms of the reaction rate divided by the stretch rate. For the blowoff branch, the boundary exhibits a linear dependence on oxygen concentration and stretch rate, indicating that the temperature at blowoff must be fairly constant. For the quenching branch, the dominance of the exponential nature of

  17. Analysis of volatile combustion products and a study of their toxicological effects.

    Science.gov (United States)

    Seader, J. D.; Einhorn, I. N.; Drake, W. O.; Mihlfeith, C. M.

    1972-01-01

    An experimental program was conducted to study the thermochemical, flammability and toxicological characteristics of uncoated and coated polyisocyanurate foams. The coatings used were fluorinated copolymer and an intumescent material. Combustion and pyrolysis gases were analyzed by gas chromatography and mass spectrometry. The LD-50 and LD-100 tests were performed on Sprague-Dawley rats housed in an environmental chamber. The isocyanurate foam, fluorinated-copolymer-coated foam, and the intumescent-coated foam were found to have excellent flammability and insulation characteristics, although smoke development was substantial.

  18. Current status of fluoride volatility method development

    Energy Technology Data Exchange (ETDEWEB)

    Uhlir, J.; Marecek, M.; Skarohlid, J. [UJV - Nuclear Research Institute, Research Centre Rez, CZ-250 68 Husinec - Rez 130 (Czech Republic)

    2013-07-01

    The Fluoride Volatility Method is based on a separation process, which comes out from the specific property of uranium, neptunium and plutonium to form volatile hexafluorides whereas most of fission products (mainly lanthanides) and higher transplutonium elements (americium, curium) present in irradiated fuel form nonvolatile tri-fluorides. Fluoride Volatility Method itself is based on direct fluorination of the spent fuel, but before the fluorination step, the removal of cladding material and subsequent transformation of the fuel into a powdered form with a suitable grain size have to be done. The fluorination is made with fluorine gas in a flame fluorination reactor, where the volatile fluorides (mostly UF{sub 6}) are separated from the non-volatile ones (trivalent minor actinides and majority of fission products). The subsequent operations necessary for partitioning of volatile fluorides are the condensation and evaporation of volatile fluorides, the thermal decomposition of PuF{sub 6} and the finally distillation and sorption used for the purification of uranium product. The Fluoride Volatility Method is considered to be a promising advanced pyrochemical reprocessing technology, which can mainly be used for the reprocessing of oxide spent fuels coming from future GEN IV fast reactors.

  19. Explosion characteristics of flammable organic vapors in nitrous oxide atmosphere.

    Science.gov (United States)

    Koshiba, Yusuke; Takigawa, Tomihisa; Matsuoka, Yusaku; Ohtani, Hideo

    2010-11-15

    Despite unexpected explosion accidents caused by nitrous oxide have occurred, few systematic studies have been reported on explosion characteristics of flammable gases in nitrous oxide atmosphere compared to those in air or oxygen. The objective of this paper is to characterize explosion properties of mixtures of n-pentane, diethyl ether, diethylamine, or n-butyraldehyde with nitrous oxide and nitrogen using three parameters: explosion limit, peak explosion pressure, and time to the peak explosion pressure. Then, similar mixtures of n-pentane, diethyl ether, diethylamine, or n-butyraldehyde with oxygen and nitrogen were prepared to compare their explosion characteristics with the mixtures containing nitrous oxide. The explosion experiments were performed in a cylindrical vessel at atmospheric pressure and room temperature. The measurements showed that explosion ranges of the mixtures containing nitrous oxide were narrow compared to those of the mixtures containing oxygen. On the other hand, the maximum explosion pressures of the mixtures containing nitrous oxide were higher than those of the mixtures containing oxygen. Moreover, our experiments revealed that these mixtures differed in equivalence ratios at which the maximum explosion pressures were observed: the pressures of the mixtures containing nitrous oxide were observed at stoichiometry; in contrast, those of the mixtures containing oxygen were found at fuel-rich area. Chemical equilibrium calculations confirmed these behaviors.

  20. Summary of flammable gas hazard and potential consequences in tank waste remediation system facility at the Hanford site

    Energy Technology Data Exchange (ETDEWEB)

    Van Vleet, R.J., Westinghouse Hanford

    1996-12-11

    This document provides a summary of the flammable gas program since 1992. It provides the best understanding of generation, retention, release of flammable gases. It gives a composition for each of the flammable gas tanks, calculates postulated concentrations in the event of a release, calculates the pressure obtained during a burn, and provides radiological and toxicological consequences. Controls from the analysis are found in WHC-SD-WM-SAR-067.

  1. Permeability and flammability study of composite sandwich structures for cryogenic applications

    Science.gov (United States)

    Bubacz, Monika

    Fiber reinforced plastics offer advantageous specific strength and stiffness compared to metals and has been identified as candidates for the reusable space transportation systems primary structures including cryogenic tanks. A number of carbon and aramid fiber reinforced plastics have been considered for the liquid hydrogen tanks. Materials selection is based upon mechanical properties and containment performance (long and short term) and upon manufacturing considerations. The liquid hydrogen tank carries shear, torque, end load, and bending moment due to gusts, maneuver, take-off, landing, lift, drag, and fuel sloshing. The tank is pressurized to about 1.5 atmosphere (14.6psi or 0.1 MPa) differential pressure and on ascent maintains the liquid hydrogen at a temperature of 20K. The objective of the research effort into lay the foundation for developing the technology required for reliable prediction of the effects of various design, manufacturing, and service parameters on the susceptibility of composite tanks to develop excessive permeability to cryogenic fuels. Efforts will be expended on developing the materials and structural concepts for the cryogenic tanks that can meet the functional requirements. This will include consideration for double wall composite sandwich structures, with inner wall to meet the cryogenic requirements. The structure will incorporate nanoparticles for properties modifications and developing barriers. The main effort will be extended to tank wall's internal skin design. The main requirements for internal composite stack are: (1) introduction of barrier film (e.g. honeycomb material paper sheet) to reduce the wall permeability to hydrogen, (2) introduction of nanoparticles into laminate resin to prevent micro-cracking or crack propagation. There is a need to characterize and analyze composite sandwich structural damage due to burning and explosion. Better understanding of the flammability and blast resistance of the composite structures

  2. Modelling leaf, plant and stand flammability for ecological and operational decision making

    Science.gov (United States)

    Zylstra, Philip

    2014-05-01

    Numerous factors have been found to affect the flammability of individual leaves and plant parts; however the way in which these factors relate to whole plant flammability, fire behaviour and the overall risk imposed by fire is not straightforward. Similarly, although the structure of plant communities is known to affect the flammability of the stand, a quantified, broadly applicable link has proven difficult to establish and validate. These knowledge gaps have presented major obstacles to the integration into fire behaviour science of research into factors affecting plant flammability, physiology, species succession and structural change, so that the management of ecosystems for fire risk is largely uninformed by these fields. The Forest Flammability Model (Zylstra, 2011) is a process-driven, complex systems model developed specifically to address this disconnect. Flame dimensions and position are calculated as properties emerging from the capacity for convective heat to propagate flame between horizontally and vertically separated leaves, branches, plants and plant strata, and this capacity is determined dynamically from the ignitability, combustibility and sustainability of those objects, their spatial arrangement and a vector-based model of the plume temperature from each burning fuel. All flammability properties as well as the physics of flame dimensions, angle and temperature distributions and the vertical structure of wind within the plant array use published sub-models which can be replaced as further work is developed. This modular structure provides a platform for the immediate application of new work on any aspect of leaf flammability or fire physics. Initial validation of the model examined its qualitative predictions for trends in forest flammability as a function of time since fire. The positive feedback predicted for the subalpine forest examined constituted a 'risky prediction' by running counter to the expectations of the existing approach, however

  3. Emerging Equity Market Volatility

    OpenAIRE

    Geert Bekaert; Harvey, Campbell R.

    1995-01-01

    Returns in emerging capital markets are very different from returns in developed markets. While most previous research has focused on average returns, we analyze the volatility of the returns in emerging equity markets. We characterize the time-series of volatility in emerging markets and explore the distributional foundations of the variance process. Of particular interest is evidence of asymmetries in volatility and the evolution of the variance process after periods of capital market refor...

  4. Volatility in Equilibrium

    DEFF Research Database (Denmark)

    Bollerslev, Tim; Sizova, Natalia; Tauchen, George

    Stock market volatility clusters in time, carries a risk premium, is fractionally inte- grated, and exhibits asymmetric leverage effects relative to returns. This paper develops a first internally consistent equilibrium based explanation for these longstanding empirical facts. The model is cast......, and the dynamic cross-correlations of the volatility measures with the returns calculated from actual high-frequency intra-day data on the S&P 500 aggregate market and VIX volatility indexes....

  5. 46 CFR 151.03-30 - Hazardous material.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Hazardous material. 151.03-30 Section 151.03-30 Shipping... BULK LIQUID HAZARDOUS MATERIAL CARGOES Definitions § 151.03-30 Hazardous material. In this part hazardous material means a liquid material or substance that is— (a) Flammable or combustible; (b...

  6. Materials Assessment of Components of the Extravehicular Mobility Unit

    Science.gov (United States)

    Olivas, John D.; Barrera, Enrique V.

    1996-01-01

    Current research interests for Extravehicular Mobility Unit (EMU) design and development are directed toward enhancements of the Shuttle EMU, implementation of the Mark 3 technology for Shuttle applications, and development of a next generation suit (the X suit) which has applications for prolonged space flight, longer extravehicular activity (EVA), and Moon and Mars missions. In this research project two principal components of the EMU were studied from the vantage point of the materials and their design criteria. An investigation of the flexible materials which make up the lay-up of materials for abrasion and tear protection, thermal insulation, pressure restrain, etc. was initiated. A central focus was on the thermal insulation. A vacuum apparatus for measuring the flexibility of the materials was built to access their durability in vacuum. Plans are to include a Residual Gas Analyzer on the vacuum chamber to measure volatiles during the durability testing. These tests will more accurately simulate space conditions and provide information which has not been available on the materials currently used on the EMU. Durability testing of the aluminized mylar with a nylon scrim showed that the material strength varied in the machine and transverse directions. Study of components of the EMU also included a study of the EMU Bearing Assemblies as to materials selection, engineered materials, use of coatings and flammability issues. A comprehensive analysis of the performance of the current design, which is a stainless steel assembly, was conducted and use of titanium alloys or engineered alloy systems and coatings was investigated. The friction and wear properties are of interest as are the general manufacturing costs. Recognizing that the bearing assembly is subject to an oxygen environment, all currently used materials as well as titanium and engineered alloys were evaluated as to their flammability. An aim of the project is to provide weight reduction since bearing

  7. Identification of non-volatile compounds and their migration from hot melt adhesives used in food packaging materials characterized by ultra-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry.

    Science.gov (United States)

    Vera, Paula; Canellas, Elena; Nerín, Cristina

    2013-05-01

    The identification of unknown non-volatile migrant compounds from adhesives used in food contact materials is a very challenging task because of the number of possible compounds involved, given that adhesives are complex mixtures of chemicals. The use of ultra-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (UPLC-MS/QTOF) is shown to be a successful tool for identifying non-targeted migrant compounds from two hot melt adhesives used in food packaging laminates. Out of the seven migrants identified and quantified, five were amides and one was a compound classified in Class II of the Cramer toxicity. None of the migration values exceeded the recommended Cramer exposure values.

  8. Comparison of dilution effects of R134a and nitrogen on flammable hydrofluorocarbons

    Institute of Scientific and Technical Information of China (English)

    Zhenming Li; Maoqiong Gong; Jianfeng Wu; Yuan Zhou

    2009-01-01

    An experimental apparatus has been built to measure the flammability limits of combustible gases based on Chi-nese national standard GB/T 12474-90. The flammability limits of four binary mixtures of R161/R134a, Ri52a/R134a, RI61/N2 and RI52a/N2 were measured with this apparatus at atmospheric pressure and ambient temperature. The fuel inertization points (FIP) of these mixtures can be found from the envelopes. Comparisons were made with the literature data; good agreement for most measurements was obtained. R134a was found to have a better dilution effect than nitrogen in reducing the flammability of hydrofluorocarbons.

  9. Enantiomeric separation of volatile organics by gas chromatography for the in situ analysis of extraterrestrial materials: kinetics and thermodynamics investigation of various chiral stationary phases.

    Science.gov (United States)

    Freissinet, C; Buch, A; Szopa, C; Sternberg, R

    2013-09-01

    The performances of several commercial chiral capillary columns have been evaluated with the aim of determining the one most suitable for enantiomeric separation in a gas chromatograph onboard a space probe. We compared the GC-MS response of three capillary columns coated with different chiral stationary phases (CSP) using volatile chiral organic molecules which are potential markers of a prebiotic organic chemistry. The three different chiral capillary columns are Chirasil-Val, with an amino acid derivative CSP, ChiralDex-β-PM, with a CSP composed of dissolved permethylated β-cyclodextrins in polysiloxane, and Chirasil-Dex, with a CSP made of modified cyclodextrins chemically bonded to the polysiloxane backbone. Both kinetics and thermodynamics studies have been carried out to evaluate the chiral recognition potential in these different types of columns. The thermodynamic parameters also allow a better understanding of the driving forces affecting the retention and separation of the enantiomers. The Chirasil-Dex-CSP displays the best characteristics for an optimal resolution of the chiral compounds, without preliminary derivatization. This CSP had been chosen to be the only chiral column in the Sample Analysis at Mars (SAM) experiment onboard the current Mars Science Laboratory (MSL) mission, and is also part of the Mars Organic Molecules Analyzer (MOMA) gas chromatograph onboard the next Martian mission ExoMars. The use of this column could also be extended to all space missions aimed at studying chirality in space.

  10. Volatile compounds in meat and meat products

    Directory of Open Access Journals (Sweden)

    Monika KOSOWSKA

    Full Text Available Abstract Meaty flavor is composed of a few hundreds of volatile compounds, only minor part of which are responsible for the characteristic odor. It is developed as a result of multi-directional reactions proceeding between non-volatile precursors contained in raw meat under the influence of temperature. The volatile compounds are generated upon: Maillard reactions, lipid oxidation, interactions between Maillard reaction products and lipid oxidation products as well as upon thiamine degradation. The developed flavor is determined by many factors associated with: raw material (breed, sex, diet and age of animal, conditions and process of slaughter, duration and conditions of meat storage, type of muscle, additives applied and the course of the technological process. The objective of this review article is to draw attention to the issue of volatile compounds characteristic for meat products and factors that affect their synthesis.

  11. Processing and Characterization of Flame Retardant Cotton Blend Nonwovens for Soft Furnishings to Meet Federal Flammability Standards

    Science.gov (United States)

    Effective July 1, 2007, it is mandatory that all mattress sets meet the federal flammability standard CFR 1633. It is necessary to impart flame resistance that would provide at least 30 minutes for occupants to escape fire. Changes in the flammability laws are expected on soft furnishings of sleep ...

  12. Assessing and ranking the flammability of some ornamental plant species to select firewise plants for landscaping in WUI (SE France).

    Science.gov (United States)

    Ganteaume, A.; Jappiot, M.; Lampin, C.

    2012-04-01

    The increasing urbanization of Wildland-Urban Interfaces (WUI) as well as the high fire occurrence in these areas requires the assessment and the ranking of the flammability of the ornamental vegetation surrounding houses especially that planted in hedges. Thus, the flammability of seven species, among those most frequently planted in hedges in Provence (South-Eastern France), were studied at particle level and at dead surface fuel level (litters) under laboratory conditions. The flammability parameters (ignition frequency, time-to-ignition, flaming duration) of the very fine particles (live leaves and particles Cupressus sempervirens litter had the highest bulk density and the longest flaming duration but the lowest flame propagation. Pyracantha coccinea litter was the longest to ignite and flame propagation was low but lasted a long time. Hierarchical cluster analysis performed on the flammability parameters of live leaves and of litters ranked the seven species in four distinct clusters from the most flammable (Prunus laurocerasus and Pyracantha coccinea) to the least flammable (Pittosporum tobira and Nerium oleander); the other species displaying two groups of intermediate flammabilities (Phyllostachys sp.- Photinia fraseri and Cupressus sempervirens ). The species with highly flammable characteristics should not be used in hedges planted in WUIs in South-Eastern France.

  13. Understanding Financial Market Volatility

    NARCIS (Netherlands)

    A. Opschoor (Anne)

    2014-01-01

    markdownabstract__Abstract__ Volatility has been one of the most active and successful areas of research in time series econometrics and economic forecasting in recent decades. Loosely speaking, volatility is defined as the average magnitude of fluctuations observed in some phenomenon over time. Wi

  14. Improving Garch Volatility Forecasts

    NARCIS (Netherlands)

    Klaassen, F.J.G.M.

    1998-01-01

    Many researchers use GARCH models to generate volatility forecasts. We show, however, that such forecasts are too variable. To correct for this, we extend the GARCH model by distinguishing two regimes with different volatility levels. GARCH effects are allowed within each regime, so that our model

  15. Understanding Financial Market Volatility

    NARCIS (Netherlands)

    A. Opschoor (Anne)

    2014-01-01

    markdownabstract__Abstract__ Volatility has been one of the most active and successful areas of research in time series econometrics and economic forecasting in recent decades. Loosely speaking, volatility is defined as the average magnitude of fluctuations observed in some phenomenon over

  16. Volatile metabolites from actinomycetes

    DEFF Research Database (Denmark)

    Scholler, C.E.G.; Gurtler, H.; Pedersen, R.

    2002-01-01

    Twenty-six Streptomyces spp. were screened for their volatile production capacity on yeast starch agar. The volatile organic compounds (VOCs) were concentrated on a porous polymer throughout an 8-day growth period. VOCs were analyzed by gas chromatography with flame ionization detection and ident...

  17. Influence of natural or organophilic bentonite for flammable of the poly(ethylene-co-vinyl acetate); Influencia da bentonita natural ou organofilica na inflamabilidade do poli(etileno-co-acetato de vinila)

    Energy Technology Data Exchange (ETDEWEB)

    Heyder, Eduardo T.; Kloss, Juliana R.; Morita, Reinaldo Y., E-mail: yomorita1@gmail.com [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba,PR (Brazil). Departamento de Quimica e Biologia; Caetano, Elenice H.; Andrade, Andre Vitor C. de [Universidade Estadual de Ponta Grossa (UEPG), Ponta Grossa, PR (Brazil); Barbosa, Ronilson V. [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Departamento de Quimica

    2013-07-01

    The manufacture polymeric applied in electrical sector in general use additives which act as flame retardants, for example, some borates, phosphates, and halogenated hydroxides. An alternative material for this purpose frequently reported in the literature because the flame resistance or flame retardancy is organoclay. Thus, the objective of this study is to evaluate the flammability of mixtures of EVA/natural bentonite and EVA/organoclay containing modifier as a species free of quaternary ammonium ions. The natural bentonite and organoclay were characterized by X-ray diffraction and scanning electron microscopy and materials were evaluated by X-ray diffraction and the flammability test. Regarding the combustion rate values, there was a reduction of flame propagation in EVA/natural bentonite (3.0%), showing that in this case the clay without modifier acted as a physical barrier and promoted retardant action of flame. (author)

  18. Investigation into the conditions under which HFC134a may become flammable.

    CSIR Research Space (South Africa)

    Kramers, AP

    2002-01-01

    Full Text Available flammability limit of a propane/HFC134a/air mixture (Schröeder 1995). The contribution of the lubricant to the flammability of HFC134a was not well understood. The literature review and findings of the Tau Tona accident report (Department of Minerals... are also highly dependent on the type of ignition source and the volume of the vessel used. 2.1.2 Lubricants used with HFC134a Lubricants used with refrigerant 134a are mineral oils; alkyl benzenes; dibasic, polybasic and polyol esters...

  19. Will elevated CO2 alter fuel characteristics and flammability of eucalypt woodlands?

    Science.gov (United States)

    Collins, Luke; Resco, Victor; Boer, Matthias; Bradstock, Ross; Sawyer, Robert

    2016-04-01

    Rising atmospheric CO2 may enhance forest productivity via CO2 fertilisation and increased soil moisture associated with water savings, potentially resulting in increased woody plant abundance i.e. woody thickening. Changes to vegetation structure via woody thickening, as well as changes to vegetation properties (e.g. leaf characteristics and moisture content), may have important implications for ecosystem flammability and fire regimes. Understanding how elevated CO2 alters flammability and fire regimes will have implications for ecosystem dynamics, particularly carbon sequestration and emissions. We present data from Free Air CO2 Enrichment (EucFACE) and whole tree growth chamber (WTC) experiments to assess the effect of elevated CO2 on fuel properties and flammability of eucalypt woodlands. Experiments involved ambient (˜400 ppm) and elevated CO2treatments, with elevated treatments being +150 ppm and +240 ppm at EucFACE and the WTCs respectively. We examined the response of vegetation parameters known to influence ecosystem flammability, namely (i) understorey vegetation characteristics (ii) understorey fuel moisture and (iii) leaf flammability. Understorey growth experiments at EucFACE using seedlings of two common woody species (Hakea sericia, Eucalyptus tereticornis) indicate that elevated CO2 did not influence stem and leaf biomass, height or crown dimensions of seedlings after 12 months exposure to experimental treatments. Temporal changes to understorey live fuel moisture were assessed at EucFACE over an 18 month period using time lapse cameras. Understorey vegetation greenness was measured daily from digital photos using the green chromatic coordinate (GCC), an index that is highly correlated with live fuel moisture (R2 = 0.90). GCC and rates of greening and browning were not affected by elevated CO2, though they were highly responsive to soil moisture availability and temperature. This suggests that there is limited potential for elevated CO2 to alter

  20. Numerical Modeling and Experimental Validation by Calorimetric Detection of Energetic Materials Using Thermal Bimorph Microcantilever Array: A Case Study on Sensing Vapors of Volatile Organic Compounds (VOCs).

    Science.gov (United States)

    Kang, Seok-Won; Fragala, Joe; Banerjee, Debjyoti

    2015-08-31

    Bi-layer (Au-Si₃N₄) microcantilevers fabricated in an array were used to detect vapors of energetic materials such as explosives under ambient conditions. The changes in the bending response of each thermal bimorph (i.e., microcantilever) with changes in actuation currents were experimentally monitored by measuring the angle of the reflected ray from a laser source used to illuminate the gold nanocoating on the surface of silicon nitride microcantilevers in the absence and presence of a designated combustible species. Experiments were performed to determine the signature response of this nano-calorimeter platform for each explosive material considered for this study. Numerical modeling was performed to predict the bending response of the microcantilevers for various explosive materials, species concentrations, and actuation currents. The experimental validation of the numerical predictions demonstrated that in the presence of different explosive or combustible materials, the microcantilevers exhibited unique trends in their bending responses with increasing values of the actuation current.

  1. Dynamic headspace analyses of residual volatiles in pharmaceuticals.

    Science.gov (United States)

    Wampler, T P; Bowe, W A; Levy, E J

    1985-02-01

    Pharmaceutical preparations may be assayed for volatile organic compounds by purging them with a stream of inert carrier gas and collecting the organics onto a suitable sorbent material, from which they may be backflushed to a gas chromatograph. Compared to solvent extraction, the process offers advantages of increased sensitivity, ease of automation, and elimination of the solvent peak. Examples are given of three major sources of volatiles in pharmaceuticals, with the development of a method for quantitating the volatiles using an internal standard.

  2. Wire Insulation Flammability Experiment: USML-1 One Year Post Mission Summary

    Science.gov (United States)

    Greenberg, Paul S.; Sacksteder, Kurt R.; Kashiwagi, Takashi

    1994-01-01

    Herein we report the results from the Wire Insulation Flammability (WIF) Experiment performed in the Glovebox Facility on the USML-1 mission. This experiment explored various aspects of electrically induced fire scenarios in a reduced gravity environment. Under quiescent microgravity conditions, heat and mass transfer are dominated by diffusive and radiative transport; while in normal-gravity buoyancy induced convection often dominates. Of considerable scientific and practical interest is the intermediate situation of combustion occurring in the presence of imposed gas flows, with lower characteristic velocities than those induced by buoyancy in noma1 gravity. Two distinct cases naturally arise: flow direction opposed to, or concurrent with, the flame spread direction. Two tests of each kind were conducted in the WIF experiment, providing the first controlled demonstration of flame spreading in forced convection ever conducted in space. Four test modules were flown. The wire insulation, 1.5 mm in diameter, was polyethylene, extruded onto nichrome wire. Temperatures of the wh3 cores and insulation heated in quiescent and flowing environments were measured. Video and still-camera images of the samples, burning in air flowing at approximately 10 cm/sec, were recorded to obtain flame characteristics including spread rate, structure and temperature. Flame spread rates in concurrent flow were approximately twice those in opposed flow. In concurrent and opposed flow regimes, the spreading flames stabilized around a bead of molten insulation material, within which bubble nucleation was observed. An ignition attempt without flow mated a quiescent cloud of vaporized fuel which ignited dramatically yet failed to sustain normal flame spread. Finally, all tests produced substantial soot agglomerates, particularly the concurrent flow tests; and the collected soot has a morphology very distinct from soot formed in normal gravity flames. Several unexpected and unique microgravity

  3. Volatile Flavoring Compounds in Beer Produced by Wheat Extruded at Low Temperature as Auxiliary Materials%低温挤压小麦辅料啤酒挥发性风味组分分析

    Institute of Scientific and Technical Information of China (English)

    何媛媛; 郑慧; 李宏军

    2015-01-01

    In this study, quantitative&qualitative analysis of the volatile flavoring compounds in beer produced by wheat extruded at low tem-perature as auxiliary materials was done by automatic head-space sampling coupled with capillary gas chromatography. The results showed that, 8 main volatile flavoring compounds were isolated from beer including acetaldehyde, n-propanol, ethyl acetate, isobutanol, isoamyl alco-hol, isoamyl acetate, ethyl caproate and ethyl caprylate. The content of each volatile flavoring compounds were in the range of normal content of light beer. The variation coefficients of the analytic results were less than 5%and the recoveries were more than 95%, which proved good repeatability and accuracy of such method. The content of total soluble nitrogen and high, middle and low-molecular nitrogenous substances in beer detected by Lundin fraction method were 105.1 mg/100 mL, 13.9 mg/100 mL, 20.0 mg/100 mL and 71.2 mg/100 mL, respectively.%采用静态自动顶空进样结合毛细管气相色谱法对膨化小麦辅料啤酒的挥发性风味组分进行定性和定量分析。结果表明,从膨化小麦辅料啤酒中主要分离出8种挥发性风味组分,其组分及含量分别是乙醛、正丙醇、乙酸乙酯、异丁醇、异戊醇、乙酸异戊酯、己酸乙酯和辛酸乙酯。啤酒中各挥发性风味组分的含量均在淡色啤酒正常含量范围之内。该方法测量结果变异系数均小于5%,回收率均大于95%,具有很好的准确性和重复性。用隆丁区分法测量小麦辅料啤酒中总氮和高、中、低分子氮的含量分别为总可溶性氮105.1 mg/100 mL、高分子氮13.9 mg/100 mL、中分子氮20.0 mg/100 mL、低分子氮71.2 mg/100 mL。

  4. Idiosyncratic Volatility Puzzle

    DEFF Research Database (Denmark)

    Aslanidis, Nektarios; Christiansen, Charlotte; Lambertides, Neophytos;

    from a large pool of macroeconomic and Önancial variables. Cleaning for macro-Önance e§ects reverses the puzzling negative relation between returns and idiosyncratic volatility documented previously. Portfolio analysis shows that the e§ects from macro-Önance factors are economically strong......In this paper, we scrutinize the cross-sectional relation between idiosyncratic volatility and stock returns. As a novelty, the idiosyncratic volatility is obtained by conditioning upon macro-Önance factors as well as upon traditional asset pricing factors. The macro-Önance factors are constructed...

  5. Numerical Modeling and Experimental Validation by Calorimetric Detection of Energetic Materials Using Thermal Bimorph Microcantilever Array: A Case Study on Sensing Vapors of Volatile Organic Compounds (VOCs)

    Science.gov (United States)

    Kang, Seok-Won; Fragala, Joe; Banerjee, Debjyoti

    2015-01-01

    Bi-layer (Au-Si3N4) microcantilevers fabricated in an array were used to detect vapors of energetic materials such as explosives under ambient conditions. The changes in the bending response of each thermal bimorph (i.e., microcantilever) with changes in actuation currents were experimentally monitored by measuring the angle of the reflected ray from a laser source used to illuminate the gold nanocoating on the surface of silicon nitride microcantilevers in the absence and presence of a designated combustible species. Experiments were performed to determine the signature response of this nano-calorimeter platform for each explosive material considered for this study. Numerical modeling was performed to predict the bending response of the microcantilevers for various explosive materials, species concentrations, and actuation currents. The experimental validation of the numerical predictions demonstrated that in the presence of different explosive or combustible materials, the microcantilevers exhibited unique trends in their bending responses with increasing values of the actuation current. PMID:26334276

  6. Numerical Modeling and Experimental Validation by Calorimetric Detection of Energetic Materials Using Thermal Bimorph Microcantilever Array: A Case Study on Sensing Vapors of Volatile Organic Compounds (VOCs

    Directory of Open Access Journals (Sweden)

    Seok-Won Kang

    2015-08-01

    Full Text Available Bi-layer (Au-Si3N4 microcantilevers fabricated in an array were used to detect vapors of energetic materials such as explosives under ambient conditions. The changes in the bending response of each thermal bimorph (i.e., microcantilever with changes in actuation currents were experimentally monitored by measuring the angle of the reflected ray from a laser source used to illuminate the gold nanocoating on the surface of silicon nitride microcantilevers in the absence and presence of a designated combustible species. Experiments were performed to determine the signature response of this nano-calorimeter platform for each explosive material considered for this study. Numerical modeling was performed to predict the bending response of the microcantilevers for various explosive materials, species concentrations, and actuation currents. The experimental validation of the numerical predictions demonstrated that in the presence of different explosive or combustible materials, the microcantilevers exhibited unique trends in their bending responses with increasing values of the actuation current.

  7. Calculation of the upper flammability limit of methane/air mixtures at elevated pressures and temperatures.

    Science.gov (United States)

    Van den Schoor, F; Verplaetsen, F; Berghmans, J

    2008-05-30

    Four different numerical methods to calculate the upper flammability limit of methane/air mixtures at initial pressures up to 10 bar and initial temperatures up to 200 degrees C are evaluated by comparison with experimental data. Planar freely propagating flames are calculated with the inclusion of a radiation heat loss term in the energy conservation equation to numerically obtain flammability limits. Three different reaction mechanisms are used in these calculations. At atmospheric pressure, the results of these calculations are satisfactory. At elevated pressures, however, large discrepancies are found. The spherically expanding flame calculations only show a marginal improvement compared with the planar flame calculations. On the other hand, the application of a limiting burning velocity with a pressure dependence Su,lim approximately p(-1/2) is found to predict the pressure dependence of the upper flammability limit very well, whereas the application of a constant limiting flame temperature is found to slightly underestimate the temperature dependence of the upper flammability limit.

  8. Flammable gas safety program. Analytical methods development: FY 1994 progress report

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, J.A.; Clauss, S.; Grant, K.; Hoopes, V.; Lerner, B.; Lucke, R.; Mong, G.; Rau, J.; Wahl, K.; Steele, R.

    1994-09-01

    This report describes the status of developing analytical methods to account for the organic components in Hanford waste tanks, with particular focus on tanks assigned to the Flammable Gas Watch List. The methods that have been developed are illustrated by their application to samples obtained from Tank 241-SY-101 (Tank 101-SY).

  9. 14 CFR 26.39 - Newly produced airplanes: Fuel tank flammability.

    Science.gov (United States)

    2010-01-01

    ... TRANSPORTATION AIRCRAFT CONTINUED AIRWORTHINESS AND SAFETY IMPROVEMENTS FOR TRANSPORT CATEGORY AIRPLANES Fuel...) that meet the requirements of 14 CFR 25.981 in effect on December 26, 2008. (1) The fuel tank is... tank exceeds a Fleet Average Flammability Exposure of 7 percent. (c) All other fuel tanks that...

  10. Flammability limits in flowing ethene-air-nitrogen mixtures: an experimental study

    NARCIS (Netherlands)

    Bolk, J.W.; Siccama, N.B.; Westerterp, K.R.

    1996-01-01

    A large pilot plant was constructed to study the upper flammability limit of ethene-air-nitrogen mixtures under conditions of flow. The gas mixtures flowed through an explosion tube with a length of 3.0 m and a diameter of 21 mm. An electrically heated wire was used as ignition source. Experiments w

  11. 30 CFR 35.22 - Test to determine effect of evaporation on flammability.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Test to determine effect of evaporation on... § 35.22 Test to determine effect of evaporation on flammability. (a) Purpose. The purpose of this test shall be to determine the effect of evaporation on the reduction of fire resistance of a hydraulic...

  12. Species composition and fire: non-additive Mixture effects on ground fuel flammability.

    NARCIS (Netherlands)

    Altena, C.; Logtestijn, R.S.P.; Cornwell, W.K.; Cornelissen, J.H.C.

    2012-01-01

    Diversity effects on many aspects of ecosystem function have been well documented. However, fire is an exception: fire experiments have mainly included single species, bulk litter, or vegetation, and, as such, the role of diversity as a determinant of flammability, a crucial aspect of ecosystem func

  13. Flammable gas issues in double-contained receiver tanks. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Peurrung, L.M.; Mahoney, L.A.; Stewart, C.W.; Gauglitz, P.A.; Pederson, L.R.; Bryan, S.A.; Shepard, C.L.

    1998-06-01

    Four double-contained receiver tanks (DCRTs) at Hanford will be used to store salt-well pumped liquids from tanks on the Flammable Gas Watch List. This document was created to serve as a technical basis or reference document for flammable gas issues in DCRTs. The document identifies, describes, evaluates, and attempts to quantify potential gas carryover and release mechanisms. It estimates several key parameters needed for these calculations, such as initial aqueous concentrations and ventilation rate, and evaluates the uncertainty in those estimates. It justifies the use of the Schumpe model for estimating vapor-liquid equilibrium constants. It identifies several potential waste compatibility issues (such as mixing and pH or temperature changes) that could lead to gas release and provides a basis for calculating their effects. It evaluates the potential for gas retention in precipitated solids within a DCRT and whether retention could lead to a buoyant displacement instability (rollover) event. It discusses rates of radiolytic, thermal, and corrosive hydrogen generation within the DCRT. It also describes in detail the accepted method of calculating the lower flammability limit (LFL) for mixtures of flammable gases.

  14. Group-Contribution based Property Estimation and Uncertainty analysis for Flammability-related Properties

    DEFF Research Database (Denmark)

    Frutiger, Jerome; Marcarie, Camille; Abildskov, Jens

    2016-01-01

    This study presents new group contribution (GC) models for the prediction of Lower and Upper Flammability Limits (LFL and UFL), Flash Point (FP) and Auto Ignition Temperature (AIT) of organic chemicals applying the Marrero/Gani (MG) method. Advanced methods for parameter estimation using robust...

  15. Analysis of flammability in the attached buildings to containment under severe accident conditions

    Energy Technology Data Exchange (ETDEWEB)

    Rosa, J.C. de la, E-mail: juan-carlos.de-la-rosa-blul@ec.europa.eu [European Commission Joint Research Centre (Netherlands); Fornós, Joan, E-mail: jfornosh@anacnv.com [Asociación Nuclear Ascó-Vandellós (Spain)

    2016-11-15

    Highlights: • Analysis of flammability conditions in buildings outside containment. • Stepwise approach easily applicable for any kind of containment and attached buildings layout. • Detailed application for real plant conditions has been included. - Abstract: Right after the events unfolded in Fukushima Daiichi, the European Union countries agreed in subjecting Nuclear Power Plants to Stress Tests as developed by WENRA and ENSREG organizations. One of the results as implemented in many European countries derived from such tests consisted of mandatory technical instructions issued by nuclear regulatory bodies on the analysis of potential risk of flammable gases in attached buildings to containment. The current study addresses the key aspects of the analysis of flammable gases leaking to auxiliary buildings attached to Westinghouse large-dry PWR containment for the specific situation where mitigating systems to prevent flammable gases to grow up inside containment are available, and containment integrity is preserved – hence avoiding isolation system failure. It also provides a full practical exercise where lessons learned derived from the current study – hence limited to the imposed boundary conditions – are applied. The leakage of gas from the containment to the support buildings is based on separate calculations using the EPRI-owned Modular Accident Analysis Program, MAAP4.07. The FATE™ code (facility Flow, Aerosol, Thermal, and Explosion) was used to model the transport and distribution of leaked flammable gas (H{sub 2} and CO) in the penetration buildings. FATE models the significant mixing (dilution) which occurs as the released buoyant gas rises and entrains air. Also, FATE accounts for the condensation of steam on room surfaces, an effect which acts to concentrate flammable gas. The results of the analysis show that during a severe accident, flammable conditions are unlikely to occur in compartmentalized buildings such as the one used in the

  16. On guidance and volatility

    NARCIS (Netherlands)

    Billings, M.B.; Jennings, R.; Lev, B.

    2013-01-01

    Survey evidence suggests that managers voluntarily disclose information, particularly earnings guidance, with an aim toward dampening share price volatility. Yet, consultants and influential institutions advise against providing guidance — citing fears of litigation and market penalties associated w

  17. Dynamic Volatility Arbitrage

    DEFF Research Database (Denmark)

    Dorn, Jochen

    profit on well-developed markets. Dynamic participation features on cross asset portfolios are at rst sight a remedy to that dilemma. Based on volatility thresholds and portfolio re-balancing, the fund engineers try to create a "volatility guaranteed" investment opportunity by surfing on the unusual high...... concepts, next to nothing is known about position reverting strategies and how, and -even more important- in which context they are applied in practice. In the recent market downturn only one sector generated signicant profits for the leading investment banks: Volatility trading activities, namely on Forex......, interest rates and commodities. If an investor positions himself on the (volatility) market within a long/short trading framework, he typically bets on a traditional mispricing arbitrage. However as this corresponds to a call spread with equal exercise prices, this strategy alone would not generate enough...

  18. It’s all about volatility of volatility

    DEFF Research Database (Denmark)

    Grassi, Stefano; Santucci de Magistris, Paolo

    2015-01-01

    for the realized volatility series. It emerges that during the recent financial crisis the relative weight of the daily component dominates over the monthly term. The estimates of the two factor stochastic volatility model suggest that the change in the dynamic structure of the realized volatility during...... the financial crisis is due to the increase in the volatility of the persistent volatility term. A set of Monte Carlo simulations highlights the robustness of the methodology adopted in tracking the dynamics of the parameters....

  19. PRELIMINARY DISCUSS ON EXPLOSION SUPPRESSION TECHNIQUE OF FLAMMABLE GAS CLOUD%可燃气云抑爆技术初探

    Institute of Scientific and Technical Information of China (English)

    汪剑辉; 刘飞; 薛一江

    2011-01-01

    Tests indicate that the combustion reaction process of explosion can be refrained by spraying explosion suppression materials in the process of explosion triggered or initial explosion phrase of flammable gas cloud, then explosion reaction can be interrupted or explosion intensity will be weakened strongly. Inorganic powders, inactive gas, and water mist are excellent materials on explosion suppression, which are worthy of being used widely. The mechanisms on explosion suppression of flammable gas cloud were discussed, and the most important problems for subsequent study were pointed out, which provide the reference for the application of explosion suppression technology.%试验表明,在可燃气云爆炸引发过程或爆炸初始阶段,通过喷洒抑爆材料可抑制爆炸燃烧反应进程,继而中断爆炸反应或显著削弱爆炸强度.无机粉末、惰气和水雾是性价比较高的抑爆材料,具有大面积推广的价值.探讨了可燃气云的抑爆机理,并指出可燃气云抑爆技术后续研究中亟待解决的问题,为可燃气云抑爆技术的实际应用提供了技术参考.

  20. Non-volatile memories

    CERN Document Server

    Lacaze, Pierre-Camille

    2014-01-01

    Written for scientists, researchers, and engineers, Non-volatile Memories describes the recent research and implementations in relation to the design of a new generation of non-volatile electronic memories. The objective is to replace existing memories (DRAM, SRAM, EEPROM, Flash, etc.) with a universal memory model likely to reach better performances than the current types of memory: extremely high commutation speeds, high implantation densities and retention time of information of about ten years.

  1. Flammability of Some Ornamental Species in Wildland-Urban Interfaces in Southeastern France: Laboratory Assessment at Particle Level

    Science.gov (United States)

    Ganteaume, Anne; Jappiot, Marielle; Lampin, Corinne; Guijarro, Mercedes; Hernando, Carmen

    2013-08-01

    Assessment of the flammability of ornamental vegetation (particularly hedges) planted around houses is necessary in light of the increasing urbanization of the wildland-urban interfaces (WUIs) and the high fire occurrence in such areas. The structure and flammability of seven of the species most frequently planted as hedges in Provence (southeastern France) were studied at particle level. Spatial repartition of the different types of fuel particles within plants was assessed by means of the cube method. The leaf flammability was assessed using an epiradiator as a burning device, and measurements of foliar physical characteristics and gross heat of combustion (GHC) helped to explain the results of burning experiments. Co-inertia analysis revealed that species with thin leaves were quick to ignite ( Pyracantha coccinea, Phyllostachys sp.) and species with high leaf GHC burned the longest ( Pittosporum tobira, Nerium oleander). Species presenting high ignitability ( Photinia fraseri, Phyllostachys sp. and Pyracantha coccinea) were characterized by high foliar surface area-to-volume ratio, and species presenting lower ignitability were characterized by high GHC ( Pittosporum tobira, Nerium oleander, Cupressus sempervirens). Hierarchical cluster analysis of the flammability variables (ignition frequency, time-to-ignition and flaming duration) categorized the relative flammability of the seven species (including dead Cupressus sempervirens) in five clusters of species from poorly flammable ( Pittosporum tobira) to extremely flammable (dead Cupressus sempervirens).This study provides useful information for reducing fire risk in WUIs in the study area.

  2. Metrological effectiveness of an analytical method for volatile organic compounds standard materials using post-column reaction GC/FID system.

    Science.gov (United States)

    Watanabe, Takuro; Kato, Kenji; Tsunoda, Kin-ichi; Maeda, Tsuneaki

    2008-06-30

    The metrological effectiveness of an analytical method using the post-column reaction GC/FID system was evaluated. The SI-traceable certified reference material (CRM), the eight ester phthalates mixture standard solution, was used as a sample. We assigned specific value to n-eicosane and it was used as an internal standard. A known quantity of n-eicosane was added to the CRM, and the mixture was measured with the post-column reaction GC/FID system. Six phthalate esters were chromatographically separated and determined. The assigned values by our system are in good agreement with the certified values of the CRM, and the combined uncertainties of the measurements by the present system were better than those of the CRM. Our method is classified as a primary ratio method and the specific values of many organic compounds can be assigned very precisely by using a small number of reference materials. Also, the method can make it possible to avoid the purity determination of raw materials and directly to assign their specific values after the preparation of the standard mixture. Conclusively, this post-column reaction GC/FID system is very effective for the chemical metrology.

  3. An approximate-reasoning-based method for screening flammable gas tanks

    Energy Technology Data Exchange (ETDEWEB)

    Eisenhawer, S.W.; Bott, T.F.; Smith, R.E.

    1998-03-01

    High-level waste (HLW) produces flammable gases as a result of radiolysis and thermal decomposition of organics. Under certain conditions, these gases can accumulate within the waste for extended periods and then be released quickly into the dome space of the storage tank. As part of the effort to reduce the safety concerns associated with flammable gas in HLW tanks at Hanford, a flammable gas watch list (FGWL) has been established. Inclusion on the FGWL is based on criteria intended to measure the risk associated with the presence of flammable gas. It is important that all high-risk tanks be identified with high confidence so that they may be controlled. Conversely, to minimize operational complexity, the number of tanks on the watchlist should be reduced as near to the true number of flammable risk tanks as the current state of knowledge will support. This report presents an alternative to existing approaches for FGWL screening based on the theory of approximate reasoning (AR) (Zadeh 1976). The AR-based model emulates the inference process used by an expert when asked to make an evaluation. The FGWL model described here was exercised by performing two evaluations. (1) A complete tank evaluation where the entire algorithm is used. This was done for two tanks, U-106 and AW-104. U-106 is a single shell tank with large sludge and saltcake layers. AW-104 is a double shell tank with over one million gallons of supernate. Both of these tanks had failed the screening performed by Hodgson et al. (2) Partial evaluations using a submodule for the predictor likelihood for all of the tanks on the FGWL that had been flagged previously by Whitney (1995).

  4. Estimation and Uncertainty Analysis of Flammability Properties for Computer-aided molecular design of working fluids for thermodynamic cycles

    DEFF Research Database (Denmark)

    Frutiger, Jerome; Abildskov, Jens; Sin, Gürkan

    assessment of novel working fluids relies on accurate property data. Flammability data like the lower and upper flammability limit (LFL and UFL) play an important role in quantifying the risk of fire and explosion. For novel working fluid candidates experimental values are not available for the safety...... analysis. In this case property prediction models like group contribution (GC) models can estimate flammability data. The estimation needs to be accurate, reliable and as less time consuming as possible [1]. However, GC property prediction methods frequently lack rigorous uncertainty analysis. Hence...

  5. Volatile components from Anthriscus sylvestris (L.) Hoffm

    NARCIS (Netherlands)

    Bos, R.; Koulman, A; Woerdenbag, H.J.; Quax, Wim; Pras, N.

    2002-01-01

    The volatile components of fresh leaves and roots from Anthriscus sylvestris (L.) Hoffm., obtained through hydrodistillation, were analysed by GC and GC-MS. This was compared to dichloromethane extracts of both fresh and dried leaf and root material. The monoterpene fraction (69-70%) dominated, whil

  6. Volatile components from Anthriscus sylvestris (L.) Hoffm

    NARCIS (Netherlands)

    Bos, R.; Koulman, A; Woerdenbag, H.J.; Quax, Wim; Pras, N.

    2002-01-01

    The volatile components of fresh leaves and roots from Anthriscus sylvestris (L.) Hoffm., obtained through hydrodistillation, were analysed by GC and GC-MS. This was compared to dichloromethane extracts of both fresh and dried leaf and root material. The monoterpene fraction (69-70%) dominated, whil

  7. Short Communication. Comparing flammability traits among fire-stricken (low elevation and non fire-stricken (high elevation conifer forest species of Europe: A test of the Mutch hypothesis

    Directory of Open Access Journals (Sweden)

    A. P. Dimitrakopoulos

    2013-04-01

    Full Text Available Aim of study. The flammability of the main coniferous forest species of Europe, divided into two groups according to their fire regime and altitudinal distribution, was tested in an effort to detect species-specific differences that may have an influence on community-wide fire regimes.Area of study. Conifer species comprising low- and high-elevation forests in Europe.Materials and Methods. The following conifer species were tested: low elevation; Pinus halepensis (Aleppo pine, Pinus brutia (Turkish pine, Pinus pinaster (maritime pine, Pinus pinea (stone pine and Cupressus sempervirens (cypress, high elevation (i.e., above 600 m a.s.l.; Pinus sylvestris (Scots pine, Abies alba (white fir, Picea excelsa (Norway spruce, Abies borissii regis (Macedonian fir and Pinus nigra (black pine. Flammability assessment (time-to-ignition and ignition temperature was conducted by an innovative ignition apparatus, heat content was measured with an IKA Adiabatic Bomb Calorimeter and ash content by heating 5 g of plant material in a muffle furnace at 650ºC for 1 h. Differences among species was statistically analysed by Duncan’s multiple comparison test.Main results. The results did not distinguish separate groups among traits between fire- and non-fire-stricken communities at the individual species level.Research highlights. Differences in fire regimes among low and high elevation conifer forests could be attributed either to differences in flammability of the plant communities as a whole (i.e., fuelbed or canopy properties vs. individual fuel properties or to other factors (climatic or anthropogenic.Key words: flammability; ignitability; heat content; ash content; conifer species; Mutch hypothesis.

  8. Oil and stock market volatility: A multivariate stochastic volatility perspective

    Energy Technology Data Exchange (ETDEWEB)

    Vo, Minh, E-mail: minh.vo@metrostate.edu

    2011-09-15

    This paper models the volatility of stock and oil futures markets using the multivariate stochastic volatility structure in an attempt to extract information intertwined in both markets for risk prediction. It offers four major findings. First, the stock and oil futures prices are inter-related. Their correlation follows a time-varying dynamic process and tends to increase when the markets are more volatile. Second, conditioned on the past information, the volatility in each market is very persistent, i.e., it varies in a predictable manner. Third, there is inter-market dependence in volatility. Innovations that hit either market can affect the volatility in the other market. In other words, conditioned on the persistence and the past volatility in their respective markets, the past volatility of the stock (oil futures) market also has predictive power over the future volatility of the oil futures (stock) market. Finally, the model produces more accurate Value-at-Risk estimates than other benchmarks commonly used in the financial industry. - Research Highlights: > This paper models the volatility of stock and oil futures markets using the multivariate stochastic volatility model. > The correlation between the two markets follows a time-varying dynamic process which tends to increase when the markets are more volatile. > The volatility in each market is very persistent. > Innovations that hit either market can affect the volatility in the other market. > The model produces more accurate Value-at-Risk estimates than other benchmarks commonly used in the financial industry.

  9. Lead-free epitaxial ferroelectric material integration on semiconducting (100) Nb-doped SrTiO3 for low-power non-volatile memory and efficient ultraviolet ray detection.

    Science.gov (United States)

    Kundu, Souvik; Clavel, Michael; Biswas, Pranab; Chen, Bo; Song, Hyun-Cheol; Kumar, Prashant; Halder, Nripendra N; Hudait, Mantu K; Banerji, Pallab; Sanghadasa, Mohan; Priya, Shashank

    2015-07-23

    We report lead-free ferroelectric based resistive switching non-volatile memory (NVM) devices with epitaxial (1-x)BaTiO3-xBiFeO3 (x = 0.725) (BT-BFO) film integrated on semiconducting (100) Nb (0.7%) doped SrTiO3 (Nb:STO) substrates. The piezoelectric force microscopy (PFM) measurement at room temperature demonstrated ferroelectricity in the BT-BFO thin film. PFM results also reveal the repeatable polarization inversion by poling, manifesting its potential for read-write operation in NVM devices. The electroforming-free and ferroelectric polarization coupled electrical behaviour demonstrated excellent resistive switching with high retention time, cyclic endurance, and low set/reset voltages. X-ray photoelectron spectroscopy was utilized to determine the band alignment at the BT-BFO and Nb:STO heterojunction, and it exhibited staggered band alignment. This heterojunction is found to behave as an efficient ultraviolet photo-detector with low rise and fall time. The architecture also demonstrates half-wave rectification under low and high input signal frequencies, where the output distortion is minimal. The results provide avenue for an electrical switch that can regulate the pixels in low or high frequency images. Combined this work paves the pathway towards designing future generation low-power ferroelectric based microelectronic devices by merging both electrical and photovoltaic properties of BT-BFO materials.

  10. Lead-free epitaxial ferroelectric material integration on semiconducting (100) Nb-doped SrTiO3 for low-power non-volatile memory and efficient ultraviolet ray detection

    Science.gov (United States)

    Kundu, Souvik; Clavel, Michael; Biswas, Pranab; Chen, Bo; Song, Hyun-Cheol; Kumar, Prashant; Halder, Nripendra N.; Hudait, Mantu K.; Banerji, Pallab; Sanghadasa, Mohan; Priya, Shashank

    2015-07-01

    We report lead-free ferroelectric based resistive switching non-volatile memory (NVM) devices with epitaxial (1-x)BaTiO3-xBiFeO3 (x = 0.725) (BT-BFO) film integrated on semiconducting (100) Nb (0.7%) doped SrTiO3 (Nb:STO) substrates. The piezoelectric force microscopy (PFM) measurement at room temperature demonstrated ferroelectricity in the BT-BFO thin film. PFM results also reveal the repeatable polarization inversion by poling, manifesting its potential for read-write operation in NVM devices. The electroforming-free and ferroelectric polarization coupled electrical behaviour demonstrated excellent resistive switching with high retention time, cyclic endurance, and low set/reset voltages. X-ray photoelectron spectroscopy was utilized to determine the band alignment at the BT-BFO and Nb:STO heterojunction, and it exhibited staggered band alignment. This heterojunction is found to behave as an efficient ultraviolet photo-detector with low rise and fall time. The architecture also demonstrates half-wave rectification under low and high input signal frequencies, where the output distortion is minimal. The results provide avenue for an electrical switch that can regulate the pixels in low or high frequency images. Combined this work paves the pathway towards designing future generation low-power ferroelectric based microelectronic devices by merging both electrical and photovoltaic properties of BT-BFO materials.

  11. Slurry growth, gas retention, and flammable gas generation by Hanford radioactive waste tanks: Synthetic waste studies, FY 1991

    Energy Technology Data Exchange (ETDEWEB)

    Bryan, S.A.; Pederson, L.R.; Ryan, J.L.; Scheele, R.D.; Tingey, J.M.

    1992-08-01

    Of 177 high-level waste storage tanks on the Hanford Site, 23 have been placed on a safety watch list because they are suspected of producing flammable gases in flammable or explosive concentrate. One tankin particular, Tank 241-SY-101 (Tank 101-SY), has exhibited slow increases in waste volume followed by a rapid decrease accompanied by venting of large quantities of gases. The purpose of this study is to help determine the processes by which flammable gases are produced, retained, and eventually released from Tank 101-SY. Waste composition data for single- and double-shell waste tanks on the flammable gas watch listare critically reviewed. The results of laboratory studies using synthetic double-shell wastes are summarized, including physical and chemical properties of crusts that are formed, the stoichiometry and rate ofgas generation, and mechanisms responsible for formation of a floating crust.

  12. Understanding Interest Rate Volatility

    DEFF Research Database (Denmark)

    Volker, Desi

    This thesis is the result of my Ph.D. studies at the Department of Finance of the Copenhagen Business School. It consists of three essays covering topics related to the term structure of interest rates, monetary policy and interest rate volatility. The rst essay, \\Monetary Policy Uncertainty...... and Interest Rates", examines the role of monetary policy uncertainty on the term structure of interest rates. The second essay, \\A Regime-Switching A ne Term Structure Model with Stochastic Volatility" (co-authored with Sebastian Fux), investigates the ability of the class of regime switching models...... with and without stochastic volatility to capture the main stylized features of U.S. interest rates. The third essay, \\Variance Risk Premia in the Interest Rate Swap Market", investigates the time-series and cross-sectional properties of the compensation demanded for holding interest rate variance risk. The essays...

  13. Volatiles in protoplanetary disks

    CERN Document Server

    Pontoppidan, Klaus M; Bergin, Edwin A; Brittain, Sean; Marty, Bernard; Mousis, Olvier; Oberg, Karin L

    2014-01-01

    Volatiles are compounds with low sublimation temperatures, and they make up most of the condensible mass in typical planet-forming environments. They consist of relatively small, often hydrogenated, molecules based on the abundant elements carbon, nitrogen and oxygen. Volatiles are central to the process of planet formation, forming the backbone of a rich chemistry that sets the initial conditions for the formation of planetary atmospheres, and act as a solid mass reservoir catalyzing the formation of planets and planetesimals. This growth has been driven by rapid advances in observations and models of protoplanetary disks, and by a deepening understanding of the cosmochemistry of the solar system. Indeed, it is only in the past few years that representative samples of molecules have been discovered in great abundance throughout protoplanetary disks - enough to begin building a complete budget for the most abundant elements after hydrogen and helium. The spatial distributions of key volatiles are being mapped...

  14. Stochastic volatility selected readings

    CERN Document Server

    Shephard, Neil

    2005-01-01

    Neil Shephard has brought together a set of classic and central papers that have contributed to our understanding of financial volatility. They cover stocks, bonds and currencies and range from 1973 up to 2001. Shephard, a leading researcher in the field, provides a substantial introduction in which he discusses all major issues involved. General Introduction N. Shephard. Part I: Model Building. 1. A Subordinated Stochastic Process Model with Finite Variance for Speculative Prices, (P. K. Clark). 2. Financial Returns Modelled by the Product of Two Stochastic Processes: A Study of Daily Sugar Prices, 1961-7, S. J. Taylor. 3. The Behavior of Random Variables with Nonstationary Variance and the Distribution of Security Prices, B. Rosenberg. 4. The Pricing of Options on Assets with Stochastic Volatilities, J. Hull and A. White. 5. The Dynamics of Exchange Rate Volatility: A Multivariate Latent Factor ARCH Model, F. X. Diebold and M. Nerlove. 6. Multivariate Stochastic Variance Models. 7. Stochastic Autoregressive...

  15. Estimation and Uncertainty Analysis of Flammability Properties for Computer-aided molecular design of working fluids for thermodynamic cycles

    OpenAIRE

    Frutiger, Jerome; Abildskov, Jens; Sin, Gürkan

    2015-01-01

    Computer Aided Molecular Design (CAMD) is an important tool to generate, test and evaluate promising chemical products. CAMD can be used in thermodynamic cycle for the design of pure component or mixture working fluids in order to improve the heat transfer capacity of the system. The safety assessment of novel working fluids relies on accurate property data. Flammability data like the lower and upper flammability limit (LFL and UFL) play an important role in quantifying the risk of fire and e...

  16. THE IMPACT OF OZONE ON THE LOWER FLAMMABLE LIMIT OF HYDROGEN IN VESSELS CONTAINING SAVANNAH RIVER SITE HIGH LEVEL WASTE

    Energy Technology Data Exchange (ETDEWEB)

    Sherburne, Carol [Savannah River Site (SRS), Aiken, SC (United States). Savannah River Remediation, LLC; Osterberg, Paul [Fauske and Associates, LLC, Burr Ridge, IL (United States); Johnson, Tom [Fauske and Associates, LLC, Burr Ridge, IL (United States); Frawely, Thomas [Fauske and Associates, LLC, Burr Ridge, IL (United States)

    2013-01-23

    The Savannah River Site, in conjunction with AREVA Federal services, has designed a process to treat dissolved radioactive waste solids with ozone. It is known that in this radioactive waste process, radionuclides radiolytically break down water into gaseous hydrogen and oxygen, which presents a well defined flammability hazard. Flammability limits have been established for both ozone and hydrogen separately; however, there is little information on mixtures of hydrogen and ozone. Therefore, testing was designed to provide critical flammability information necessary to support safety related considerations for the development of ozone treatment and potential scale-up to the commercial level. Since information was lacking on flammability issues at low levels of hydrogen and ozone, a testing program was developed to focus on filling this portion of the information gap. A 2-L vessel was used to conduct flammability tests at atmospheric pressure and temperature using a fuse wire ignition source at 1 percent ozone intervals spanning from no ozone to the Lower Flammable Limit (LFL) of ozone in the vessel, determined as 8.4%(v/v) ozone. An ozone generator and ozone detector were used to generate and measure the ozone concentration within the vessel in situ, since ozone decomposes rapidly on standing. The lower flammability limit of hydrogen in an ozone-oxygen mixture was found to decrease from the LFL of hydrogen in air, determined as 4.2 % (v/v) in this vessel. From the results of this testing, Savannah River was able to develop safety procedures and operating parameters to effectively minimize the formation of a flammable atmosphere.

  17. Pricing Volatility of Stock Returns with Volatile and Persistent Components

    DEFF Research Database (Denmark)

    Zhu, Jie

    2009-01-01

    This paper introduces a two-component volatility model based on first moments of both components to describe the dynamics of speculative return volatility. The two components capture the volatile and the persistent part of volatility, respectively. The model is applied to 10 Asia-Pacific stock...... markets. Their in-mean effects on returns are tested. The empirical results show that the persistent component is much more important for the volatility dynamic process than is the volatile component. However, the volatile component is found to be a significant pricing factor of asset returns for most...... markets. A positive or risk-premium effect exists between the return and the volatile component, yet the persistent component is not significantly priced for the return dynamic process....

  18. Methodology for Predicting Flammable Gas Mixtures in Double Contained Receiver Tanks [SEC 1 THRU SEC 3

    Energy Technology Data Exchange (ETDEWEB)

    HEDENGREN, D.C.

    2000-01-31

    This methodology document provides an estimate of the maximum concentrations of flammable gases (ammonia, hydrogen, and methane) which could exist in the vapor space of a double-contained receiver tank (DCRT) from the simultaneous saltwell pumping of one or more single-shell tanks (SSTs). This document expands Calculation Note 118 (Hedengren et a1 1997) and removes some of the conservatism from it, especially in vapor phase ammonia predictions. The methodologies of Calculation Note 118 (Hedengren et a1 1997) are essentially identical for predicting flammable gas mixtures in DCRTs from saltwell pumping for low DCRT ventilation rates, 1e, < 1 cfm. The hydrogen generation model has also been updated in the methodology of this document.

  19. Laboratory flammability studies of mixtures of hydrogen, nitrous oxide, and air

    Energy Technology Data Exchange (ETDEWEB)

    Cashdollar, K L; Hertzberg, M; Zlochower, I A; Lucci, C E; Green, G M; Thomas, R A [Bureau of Mines, Pittsburgh, PA (United States). Pittsburgh Research Center

    1992-06-26

    At the request of the Department of Energy and the Westinghouse Hanford Company, the Bureau of Mines has investigated the flammability of mixtures of hydrogen, nitrous oxide, and air. This work is relevant to the possible hazards of flammable gas generation from nuclear waste tanks at Hanford, WA. The tests were performed in a 120-L spherical chamber under both quiescent and turbulent conditions using both electric spark and pyrotechnic ignition sources. The data reported here for binary mixtures of hydrogen in air generally confirm the data of previous investigators, but they are more comprehensive than those reported previously. The results clarify to a greater extent the complications associated with buoyancy, turbulence, and selective diffusion. The data reported here for ternary mixtures of hydrogen and nitrous oxide in air indicate that small additions of nitrous oxide (relative to the amount of air) have little effect, but that higher concentrations of nitrous oxide (relative to air) significantly increase the explosion hazard.

  20. A Review of the Flammability Factors of Kenaf and Allied Fibre Reinforced Polymer Composites

    Directory of Open Access Journals (Sweden)

    C. H. Lee

    2014-01-01

    Full Text Available Natural fibre is a well-known reinforcement fibre in polymer-matrix Composites (PMC lately. Natural fibre has fast growing and abundance properties which make it available at very low cost. For kenaf fibre there is long lists of research projects which have been done regarding its behaviour, and properties and modification made to it. In this paper, fire flammability is the main concern for natural fibre reinforced polymer (NFRP composites especially kenaf fibre. To estimate its flammability, a wide range of factors can be considered such as fibre content, type of matrices, pH conditions, treatment, and fire retardant (FR filler’s type. The most important criteria are the ignition time, rate of propagation, and fire behavior. thermogravimetric analysis (TGA, different scanning calorimetric (DSC, and dynamic mechanical analysis (DMA are the three most famous methods used to investigate the fire behaviour of composites.

  1. Estimation and Uncertainty Analysis of Flammability Properties of Chemicals using Group-Contribution Property Models

    DEFF Research Database (Denmark)

    Frutiger, Jerome; Abildskov, Jens; Sin, Gürkan

    or time constraints, property prediction models like group contribution (GC) models can estimate flammability data. The estimation needs to be accurate, reliable and as less time consuming as possible. However, GC property prediction methods frequently lack rigorous uncertainty analysis. Hence......, there is no information about the reliability of the data. Furthermore, the global optimality of the GC parameters estimation is often not ensured. In this research project flammability-related property data, like LFL and UFL, are estimated using the Marrero and Gani group contribution method (MG method). In addition...... the group contribution in three levels: The contributions from a specific functional group (1st order parameters), from polyfunctional (2nd order parameters) as well as from structural groups (3rd order parameters). The latter two classes of GC factors provide additional structural information beside...

  2. Pricing Volatility of Stock Returns with Volatile and Persistent Components

    DEFF Research Database (Denmark)

    Zhu, Jie

    In this paper a two-component volatility model based on the component's first moment is introduced to describe the dynamic of speculative return volatility. The two components capture the volatile and persistent part of volatility respectively. Then the model is applied to 10 Asia-Pacific stock m......, a positive or risk-premium effect exists between return and the volatile component, yet the persistent component is not significantly priced for return dynamic process.......In this paper a two-component volatility model based on the component's first moment is introduced to describe the dynamic of speculative return volatility. The two components capture the volatile and persistent part of volatility respectively. Then the model is applied to 10 Asia-Pacific stock...... markets. Their in-mean effects on return are also tested. The empirical results show that the persistent component accounts much more for volatility dynamic process than the volatile component. However the volatile component is found to be a significant pricing factor of asset returns for most markets...

  3. The hydrogen–air burning rate near the lean flammability limit

    OpenAIRE

    Fernández Galisteo, Daniel; Sánchez Pérez, Antonio Luis; Liñán Martínez, Amable; Williams, F. A.

    2009-01-01

    This paper investigates the inner structure of the thin reactive layer of hydrogen–air fuellean deflagrations close to the flammability limit. The analysis, which employs seven elementary reactions for the chemistry description, uses the ratio of the characteristic radical and fuel concentrations as a small asymptotic parameter, enabling an accurate analytic expression for the resulting burning rate to be derived. The analysis reveals that the steady-state assumption for chemical intermedi...

  4. Prediction of upper flammability limit percent of pure compounds from their molecular structures.

    Science.gov (United States)

    Gharagheizi, Farhad

    2009-08-15

    In this study, a quantitative structure-property relationship (QSPR) is presented to predict the upper flammability limit percent (UFLP) of pure compounds. The obtained model is a five parameters multi-linear equation. The parameters of the model are calculated only from chemical structure. The average absolute error and squared correlation coefficient of the obtained model over all 865 pure compounds used to develop the model are 9.7%, and 0.92, respectively.

  5. Operation of the multigap resistive plate chamber using a gas mixture free of flammable components

    CERN Document Server

    Akindinov, A; Antonioli, P; Arcelli, S; Basile, M; Cara Romeo, G; Cifarelli, Luisa; Cindolo, F; De Caro, A; De Pasquale, S; Di Bartolomeo, A; Fusco-Girard, M; Golovine, V; Guida, M; Hatzifotiadou, D; Kaidalov, A B; Kim, D H; Kim, D W; Kisselev, S M; Laurenti, G; Lee, K; Lee, S C; Lioublev, E; Luvisetto, M L; Margotti, A; Martemyanov, A N; Nania, R; Noferini, F; Otiougova, P; Pesci, A; Pinazza, O; Polozov, P A; Scapparone, E; Scioli, G; Sellitto, S B; Semeria, F; Smirnitsky, A V; Tchoumakov, M M; Usenko, E; Valenti, G; Voloshin, K G; Williams, M C S; Zagreev, B V; Zampolli, C; Zichichi, A

    2004-01-01

    We have investigated the operation of the multigap resistive plate chamber (MRPC) for the ALICE-TOF system with a gas mixture free of flammable components. Two different gas mixtures, with and without iso-C//4H//1//0 have been used to measure the performance of the MRPC. The efficiency, time resolution, total charge, and the fast to total charge ratio have been found to be comparable.

  6. Qualitative Assessment of the Ignition of Highly Flammable Fuels by Primary Explosives,

    Science.gov (United States)

    1983-06-01

    primary explosives used in the investigation are listed below:- basic lead azide lead azide lead styphnate barium styphnate potassium picrate lead...in Bakelite Tubes Basic Lead Azide w Lead Styphnate LDNR Barium Styphnate I Flash Composition Potassium Picrate I TABLE 3 IGNITION OF HEXANE SOAKED...Flammability Nichrome Bridgewire in Aluminium Tube Potassium Picrate X LDVR X Barium Styphnate X Tetracene X 200 mq Lead Styphnate X 400 mq Lead

  7. Textiles: Some technocal information and data III: Low flammable and other high performance fibres

    CSIR Research Space (South Africa)

    Hunter, L

    1978-07-01

    Full Text Available importance in the flammability performance is well illustrated in the case of certain wool shag carpets. Legislation for carpets sold in Canada requires that all carpets be tested under bone dry conditions. Consequently the natural moisture content... of the wool fibres (10-14%) is not available to prevent the spread of flame. If, however, these carpets were tested under higher relative humidity conditions the burning methenamine tablet employed as ignition source would not be sufficient to cause flame...

  8. Non-flammable electrolytes based on trimethyl phosphate solvent for lithium-ion batteries

    Institute of Scientific and Technical Information of China (English)

    HU Chuan-yue; LI Xin-hai

    2005-01-01

    The properties of trimethyl phosphate(TMP)-based nonflammable electrolytes with LiPF6 as solute were investigated using graphite anode and LiCoO2 cathode. The effect of TMP on non-flammability of electrolytes was also evaluated. It is found that the TMP reduction decomposition on graphite electrode at the potential of 1.3V (vs Li/Li+) is suppressed with ethylene carbonate(EC), dimethyl carbonate(DMC) and ethylmethyl carbonate(EMC) cosolvents and vinylene carbonate(VC) additives. The results show that the non-flammable electrolyte of 1mol/L LiPF6 61%(EC1.5-DMC1.0-EMC1.0)-39% TMP has good electrochemical properties. The discharge capacities of half-cells after 20 cycles are 254.8mA·h/g for Li/graphite and 144.1mA·h/g for Li/LiCoO2. The graphite/LiCoO2 prismatic lithium-ion cell delivers a discharge capacity of 131mA·h/g at first cycle. With an addition of 4%VC to this non-flammable electrolyte, a discharge capacity of 134mA·h/g at first cycle and a capacity ratio of 84.3% after 50 cycles are obtained for prismatic lithium-ion batteries. Furthermore, a nail penetration test demonstrates that the safety of prismatic lithium-ion batteries is dramatically improved by using TMP-containing non-flammable electrolytes.

  9. Flammable gas double shell tank expert elicitation presentations (Part A and Part B)

    Energy Technology Data Exchange (ETDEWEB)

    Bratzel, D.R.

    1998-04-17

    This document is a compilation of presentation packages and white papers for the Flammable Gas Double Shell Tank Expert Elicitation Workshop {number_sign}2. For each presentation given by the different authors, a separate section was developed. The purpose for issuing these workshop presentation packages and white papers as a supporting document is to provide traceability and a Quality Assurance record for future reference to these packages.

  10. 75 FR 49379 - Correction to Internal Citation of “Extremely Flammable Solid” and “Flammable Solid”

    Science.gov (United States)

    2010-08-13

    ..., Labeling, Law enforcement, Toys. Conclusion 0 For the reasons discussed the Commission amends 16 CFR part...) and (vi). (4) Thread, string, twine, rope, cord, and similar materials are exempt from the...

  11. Flammability limits and explosion characteristics of toluene-nitrous oxide mixtures.

    Science.gov (United States)

    Vandebroek, L; Van den Schoor, F; Verplaetsen, F; Berghmans, J; Winter, H; van't Oost, E

    2005-04-11

    Flammability limits and explosion characteristics of toluene-nitrous oxide mixtures are experimentally determined in an 8l spherical vessel, and are compared with corresponding values of toluene-air mixtures. The experiments, performed at atmospheric pressure and at an initial temperature of 70 degrees C, show that the flammable range of toluene in nitrous oxide (0.25-22.5 mol%) is about three times as wide as the corresponding range of toluene in air (1.3-7.1 mol%). Maximum values of the explosion pressure ratio and the deflagration index, K(G), are clearly higher when nitrous oxide is applied as an oxidizer. This can be attributed to the increased flame temperature and burning velocity of toluene-nitrous oxide flames. Moreover, extremely high values of K(G) for near-stoichiometric mixtures in combination with strong acoustic oscillations in the pressure signals of these mixtures indicate the existence of a flame accelerating mechanism. These phenomena are enhanced when an initial pressure of 6 bara is applied. Finally, when evaluating the lower flammability limit, it was found that pure nitrous oxide decomposes at pressures above 4.5 bara when applying an ignition energy of about 10 J.

  12. Dynamics of flames near the rich-flammability limit of hydrogen-air mixtures

    Science.gov (United States)

    Kailasanath, K.; Ganguly, K.; Patnaik, G.

    1993-01-01

    Flames near the rich-flammability limit of hydrogen-air mixtures are studied using a detailed, time-dependent, one-dimensional Lagrangian model. Results from the numerical simulations indicate that a steady burning velocity is not obtained for very rich hydrogen-air mixtures. As the amount of hydrogen is increased, a damped oscillation is observed in the flame and burning velocities, and then, with further increase in the amount of hydrogen, an undamped oscillation with a complex set of frequencies is observed. Simulations with a simplified one-step irreversible chemical reaction do not show these oscillations, suggesting that chemical kinetics plays a strong role in inducing these oscillations. Further analysis shows that the oscillations are due to a competition for H atoms between chain branching and chain-terminating reactions. Simulations of spherically expanding flames suggest that stretch effects (due to curvature) will cause the oscillations to occur in less rich mixtures than that observed for planar flames. The implications of these oscillations on the rich-flammability limit as well as the role of chemical kinetics in creating a fundamental flammability limit is discussed.

  13. Effect of Zirconium Chloride as a Mordant on Flammability of Dyeing Wool with Madder

    Directory of Open Access Journals (Sweden)

    Arash Almasian

    2015-03-01

    Full Text Available In this research, the effect of zirconium salt as a mordant on flammability of dyeing wool fabric with madder was studied.Wool fabrics were treated with different concentrations of zirconium salt in water solution including 1, 3, 6 and 9% o.w.f. and the dyeing process was carried out on the fabrics in the states before, simultaneously and after-mordanting with madder. Formic acid and oxalic acid were used to generate acidic pH.The chemical characteristics and the changes induced by zirconium were investigated by Fourier-transform infrared spectra (FTIR. Flammability of samples was investigated by horizontal flammability test (HFT. The surfaces of untreated and treated fabrics were evaluated by scanning electron microscopy to observe the morphological changes. The EDX results showed presence of zirconium salt on the surface of wool.The results show that zirconium treated fabrics have a higher weight and lower bending rigidity compared to untreated ones. Furthermore,the zirconium mordant made the wool fabric hydrophobic.

  14. DWPF Melter Off-Gas Flammability Assessment for Sludge Batch 9

    Energy Technology Data Exchange (ETDEWEB)

    Choi, A. S. [Savannah River Site (SRS), Aiken, SC (United States)

    2016-07-11

    The slurry feed to the Defense Waste Processing Facility (DWPF) melter contains several organic carbon species that decompose in the cold cap and produce flammable gases that could accumulate in the off-gas system and create potential flammability hazard. To mitigate such a hazard, DWPF has implemented a strategy to impose the Technical Safety Requirement (TSR) limits on all key operating variables affecting off-gas flammability and operate the melter within those limits using both hardwired/software interlocks and administrative controls. The operating variables that are currently being controlled include; (1) total organic carbon (TOC), (2) air purges for combustion and dilution, (3) melter vapor space temperature, and (4) feed rate. The safety basis limits for these operating variables are determined using two computer models, 4-stage cold cap and Melter Off-Gas (MOG) dynamics models, under the baseline upset scenario - a surge in off-gas flow due to the inherent cold cap instabilities in the slurry-fed melter.

  15. Group-contribution based property estimation and uncertainty analysis for flammability-related properties.

    Science.gov (United States)

    Frutiger, Jérôme; Marcarie, Camille; Abildskov, Jens; Sin, Gürkan

    2016-11-15

    This study presents new group contribution (GC) models for the prediction of Lower and Upper Flammability Limits (LFL and UFL), Flash Point (FP) and Auto Ignition Temperature (AIT) of organic chemicals applying the Marrero/Gani (MG) method. Advanced methods for parameter estimation using robust regression and outlier treatment have been applied to achieve high accuracy. Furthermore, linear error propagation based on covariance matrix of estimated parameters was performed. Therefore, every estimated property value of the flammability-related properties is reported together with its corresponding 95%-confidence interval of the prediction. Compared to existing models the developed ones have a higher accuracy, are simple to apply and provide uncertainty information on the calculated prediction. The average relative error and correlation coefficient are 11.5% and 0.99 for LFL, 15.9% and 0.91 for UFL, 2.0% and 0.99 for FP as well as 6.4% and 0.76 for AIT. Moreover, the temperature-dependence of LFL property was studied. A compound specific proportionality constant (K(LFL)) between LFL and temperature is introduced and an MG GC model to estimate K(LFL) is developed. Overall the ability to predict flammability-related properties including the corresponding uncertainty of the prediction can provide important information for a qualitative and quantitative safety-related risk assessment studies.

  16. Evaporative fractionation of volatile stable isotopes and their bearing on the origin of the Moon.

    Science.gov (United States)

    Day, James M D; Moynier, Frederic

    2014-09-13

    The Moon is depleted in volatile elements relative to the Earth and Mars. Low abundances of volatile elements, fractionated stable isotope ratios of S, Cl, K and Zn, high μ ((238)U/(204)Pb) and long-term Rb/Sr depletion are distinguishing features of the Moon, relative to the Earth. These geochemical characteristics indicate both inheritance of volatile-depleted materials that formed the Moon and planets and subsequent evaporative loss of volatile elements that occurred during lunar formation and differentiation. Models of volatile loss through localized eruptive degassing are not consistent with the available S, Cl, Zn and K isotopes and abundance data for the Moon. The most probable cause of volatile depletion is global-scale evaporation resulting from a giant impact or a magma ocean phase where inefficient volatile loss during magmatic convection led to the present distribution of volatile elements within mantle and crustal reservoirs. Problems exist for models of planetary volatile depletion following giant impact. Most critically, in this model, the volatile loss requires preferential delivery and retention of late-accreted volatiles to the Earth compared with the Moon. Different proportions of late-accreted mass are computed to explain present-day distributions of volatile and moderately volatile elements (e.g. Pb, Zn; 5 to >10%) relative to highly siderophile elements (approx. 0.5%) for the Earth. Models of early magma ocean phases may be more effective in explaining the volatile loss. Basaltic materials (e.g. eucrites and angrites) from highly differentiated airless asteroids are volatile-depleted, like the Moon, whereas the Earth and Mars have proportionally greater volatile contents. Parent-body size and the existence of early atmospheres are therefore likely to represent fundamental controls on planetary volatile retention or loss.

  17. Dynamic Volatility Arbitrage

    DEFF Research Database (Denmark)

    Dorn, Jochen

    concepts, next to nothing is known about position reverting strategies and how, and -even more important- in which context they are applied in practice. In the recent market downturn only one sector generated signicant profits for the leading investment banks: Volatility trading activities, namely on Forex...

  18. Stock markets liberalization affects volatility?

    OpenAIRE

    Ioan Alin NISTOR; Maria-Lenuţa CIUPAC-ULICI; GHERMAN Mircea-Cristian

    2012-01-01

    Regarding the impact of liberalization, the results show that, in general, market opening is accompanied by a significant increase in market volatility. In particular, volatility tends to decrease due to large capital inflows and domestic growth.The study analyzes the impact of stock market liberalization on volatility in six emerging stock markets by using GARCH methodology. Theory on the effects of financial liberalization on volatility has been ambiguous, and empirical work has yielded con...

  19. The exploitation of volatile oil

    Institute of Scientific and Technical Information of China (English)

    MENG Teng; ZHANG Da; TENG Xiangjin; LINing; HAO Zaibin

    2007-01-01

    Rose is a kind of favorite ornamental plant. This article briefly introduced the cultivation and the use of rose around the world both in ancient time and nowadays. Today, volatile oil becomes the mainstream of the rose industry. People pay attention to the effect of volatile oil; meanwhile, they speed up their research on extracting volatile oil and the ingredients.

  20. Plant volatiles and the environment

    NARCIS (Netherlands)

    Loreto, F.; Dicke, M.; Schnitzler, J.P.; Turlings, T.C.J.

    2014-01-01

    Volatile organic compounds emitted by plants represent the largest part of biogenic volatile organic compounds (BVOCs) released into our atmosphere. Plant volatiles are formed through many biochemical pathways, constitutively and after stress induction. In recent years, our understanding of the func

  1. Review: Fuel Volatility Standards and Spark-Ignition Vehicle Driveability

    Energy Technology Data Exchange (ETDEWEB)

    Yanowitz, Janet; McCormick, Robert L.

    2016-03-14

    We've put spark-ignition engine fuel standards in place in order to ensure acceptable hot and cold weather driveability (HWD and CWD). Vehicle manufacturers and fuel suppliers have developed systems that meet our driveability requirements so effectively that drivers overwhelmingly find that their vehicles reliably start up and operate smoothly and consistently throughout the year. For HWD, fuels that are too volatile perform more poorly than those that are less volatile. Vapor lock is the apparent cause of poor HWD, but there is conflicting evidence in the literature as to where in the fuel system it occurs. Most studies have found a correlation between degraded driveability and higher dry vapor pressure equivalent or lower TV/L = 20, and less consistently with a minimum T50. For CWD, fuels with inadequate volatility can cause difficulty in starting and rough operation during engine warmup. The Driveability Index (DI)-a function of T10, T50, and T90-is well correlated with CWD in hydrocarbon fuels. For ethanol-containing fuels, a correction factor to the DI equation improves the correlation with CWD, although the best value for that factor has still not been determined. Ethanol increases the heat of vaporization. But, this is likely insignificant for E15 and lower concentration fuels. The impact of ethanol on driveability is likely due to its direct effect on vapor pressure at cold temperatures. For E51-E83 or flex-fuel blends, ASTM sets a minimum vapor pressure; however, published data suggest that a correction for the amount of ethanol in the fuel is needed to accurately predict CWD, possibly because ethanol has a higher lower-flammability limit.

  2. Latent Integrated Stochastic Volatility, Realized Volatility, and Implied Volatility: A State Space Approach

    DEFF Research Database (Denmark)

    Bach, Christian; Christensen, Bent Jesper

    We include simultaneously both realized volatility measures based on high-frequency asset returns and implied volatilities backed out of individual traded at the money option prices in a state space approach to the analysis of true underlying volatility. We model integrated volatility as a latent...... fi…rst order Markov process and show that our model is closely related to the CEV and Barndorff-Nielsen & Shephard (2001) models for local volatility. We show that if measurement noise in the observable volatility proxies is not accounted for, then the estimated autoregressive parameter in the latent...... process is downward biased. Implied volatility performs better than any of the alternative realized measures when forecasting future integrated volatility. The results are largely similar across the stock market (S&P 500), bond market (30-year U.S. T-bond), and foreign currency exchange market ($/£ )....

  3. Flammability, Odor, and Offgassing Requirements and Test Procedures for Materials in Environments That Support Combustion

    Science.gov (United States)

    1988-05-01

    Methone (dl) 2 ul in 333 ml Pungent Formic acid 25 ml of 90% solution in 500 ml Putrid Methyl disulfide (Methyl dithiomethane) 1 ul in 10,000 ml (4...pool shall not participate on the panel if their sense of smell is affected in any manner such as by recent smoking, ingestion of highly flavored foods...or exposure to pungent vapors. (10) At least one of the seven odors shall be presented to the panel as a standard for verifying the ability to

  4. 29 CFR 1910.107 - Spray finishing using flammable and combustible materials.

    Science.gov (United States)

    2010-07-01

    ... currents toward the exhaust outlet. (2) Interiors. The interior surfaces of spray booths shall be smooth... installed at the upper outer edge of the booth over the opening. (7) Conveyors. Where conveyors are arranged...) Conveyors required. Goods being painted using this process are to be supported on conveyors. The conveyors...

  5. Fire and Flammability Characteristics of Materials Used in Rail Passenger Cars. A Literature Survey.

    Science.gov (United States)

    1980-04-01

    basis. Seader and Chien54 suggested the use of mass optical density to correlate and compare data obtained on the smoke-producing characteris- tics of...be independent of the surface area of a smoking polymer. Another article by Seader and Chien 55 discussed the physical aspects of smoke development...A023 413). 54 j. D. Seader and W. P. Chien, "Mass Optical Density as a Correlating Parameter for the NBS Smoke Density Chamber," d. Fire & FlcomabiZity

  6. Organic and volatile elements in the solar system

    Directory of Open Access Journals (Sweden)

    Remusat L.

    2012-01-01

    Full Text Available Chondrites and comets have accreted primitive materials from the early solar system. Those materials include organics, water and other volatile components. The most primitive chondrites and comets have undergone few modifications on their respective parent bodies and can deliver to laboratories components that were present at the origin of the protosolar nebula. Here I present a review of the organic material and volatile components that have been studied in the most primitive chondrites, and the last data from the stardust mission about the cometary record. This paper focuses on materials that can be studied in laboratories, by mass spectrometry, ion probes or organic chemistry techniques.

  7. Silicon isotopes in angrites and volatile loss in planetesimals

    Science.gov (United States)

    Moynier, Frédéric; Savage, Paul S.; Badro, James; Barrat, Jean-Alix

    2014-01-01

    Inner solar system bodies, including the Earth, Moon, and asteroids, are depleted in volatile elements relative to chondrites. Hypotheses for this volatile element depletion include incomplete condensation from the solar nebula and volatile loss during energetic impacts. These processes are expected to each produce characteristic stable isotope signatures. However, processes of planetary differentiation may also modify the isotopic composition of geochemical reservoirs. Angrites are rare meteorites that crystallized only a few million years after calcium–aluminum-rich inclusions and exhibit extreme depletions in volatile elements relative to chondrites, making them ideal samples with which to study volatile element depletion in the early solar system. Here we present high-precision Si isotope data that show angrites are enriched in the heavy isotopes of Si relative to chondritic meteorites by 50–100 ppm/amu. Silicon is sufficiently volatile such that it may be isotopically fractionated during incomplete condensation or evaporative mass loss, but theoretical calculations and experimental results also predict isotope fractionation under specific conditions of metal–silicate differentiation. We show that the Si isotope composition of angrites cannot be explained by any plausible core formation scenario, but rather reflects isotope fractionation during impact-induced evaporation. Our results indicate planetesimals initially formed from volatile-rich material and were subsequently depleted in volatile elements during accretion. PMID:25404309

  8. Silicon isotopes in angrites and volatile loss in planetesimals.

    Science.gov (United States)

    Pringle, Emily A; Moynier, Frédéric; Savage, Paul S; Badro, James; Barrat, Jean-Alix

    2014-12-02

    Inner solar system bodies, including the Earth, Moon, and asteroids, are depleted in volatile elements relative to chondrites. Hypotheses for this volatile element depletion include incomplete condensation from the solar nebula and volatile loss during energetic impacts. These processes are expected to each produce characteristic stable isotope signatures. However, processes of planetary differentiation may also modify the isotopic composition of geochemical reservoirs. Angrites are rare meteorites that crystallized only a few million years after calcium-aluminum-rich inclusions and exhibit extreme depletions in volatile elements relative to chondrites, making them ideal samples with which to study volatile element depletion in the early solar system. Here we present high-precision Si isotope data that show angrites are enriched in the heavy isotopes of Si relative to chondritic meteorites by 50-100 ppm/amu. Silicon is sufficiently volatile such that it may be isotopically fractionated during incomplete condensation or evaporative mass loss, but theoretical calculations and experimental results also predict isotope fractionation under specific conditions of metal-silicate differentiation. We show that the Si isotope composition of angrites cannot be explained by any plausible core formation scenario, but rather reflects isotope fractionation during impact-induced evaporation. Our results indicate planetesimals initially formed from volatile-rich material and were subsequently depleted in volatile elements during accretion.

  9. Thermodynamics of Volatile Silicon Hydroxides Studied

    Science.gov (United States)

    Copland, Evan H.; Opila, Elizabeth J.; Jacobson, Nathan S.

    2001-01-01

    Silicon-based ceramics are promising candidate structural materials for heat engines. The long-term stability of these materials to environmental degradation is dependent on the formation and retention of a protective SiO2 layer. It is well known that SiO2 forms stable volatile hydroxides in the presence of water vapor at elevated temperatures. Combustion conditions, which characteristically are at high velocities, contain significant water vapor pressures, and high temperatures tend to promote continuous formation of these hydroxides with resulting material degradation. For the degradation of silicon-based ceramics to be predicted, accurate thermodynamic data on the formation of silicon hydroxides are needed.

  10. Scaling Foreign Exchange Volatility

    OpenAIRE

    Jonathan Batten; Craig Ellis

    2001-01-01

    When asset returns are normally distributed the risk of an asset over a long return interval may be estimated by scaling the risk from shorter return intervals. While it is well known that asset returns are not normally distributed a key empirical question concerns the effect that scaling the volatility of dependent processes will have on the pricing of related financial assets. This study provides an insight into this issue by investigating the return properties of the most important currenc...

  11. Flammable Gas Safety Program: actual waste organic analysis FY 1996 progress report; Flammable Gas Safety Program: actual waste organic analysis FY 1996 progress report

    Energy Technology Data Exchange (ETDEWEB)

    Clauss, S.A.; Grant, K.E.; Hoopes, V.; Mong, G.M.; Rau, J.; Steele, R.; Wahl, K.H.

    1996-09-01

    This report describes the status of optimizing analytical methods to account for the organic components in Hanford waste tanks, with emphasis on tanks assigned to the Flammable Gas Watch List. The methods developed are illustrated by their application to samples from Tanks 241-SY-103 and 241-S-102. Capability to account for organic carbon in Tank SY-101 was improved significantly by improving techniques for isolating organic constituents relatively free from radioactive contamination and by improving derivatization methodology. The methodology was extended to samples from Tank SY-103 and results documented in this report. Results from analyzing heated and irradiated SY-103 samples (Gas Generation Task) and evaluating methods for analyzing tank waste directly for chelators and chelator fragments are also discussed.

  12. Towards the development of flexible non-volatile memories.

    Science.gov (United States)

    Han, Su-Ting; Zhou, Ye; Roy, V A L

    2013-10-11

    Flexible non-volatile memories have attracted tremendous attentions for data storage for future electronics application. From device perspective, the advantages of flexible memory devices include thin, lightweight, printable, foldable and stretchable. The flash memories, resistive random access memories (RRAM) and ferroelectric random access memory/ferroelectric field-effect transistor memories (FeRAM/FeFET) are considered as promising candidates for next generation non-volatile memory device. Here, we review the general background knowledge on device structure, working principle, materials, challenges and recent progress with the emphasis on the flexibility of above three categories of non-volatile memories.

  13. Comparison and evaluation of methods for the determination of flammability limits, applied to methane/hydrogen/air mixtures.

    Science.gov (United States)

    Van den Schoor, F; Hermanns, R T E; van Oijen, J A; Verplaetsen, F; de Goey, L P H

    2008-02-11

    Different methods, both experimental and numerical, to determine the flammability limits are compared and evaluated, exemplified by a determination of the flammability limits of methane/hydrogen/air mixtures for hydrogen fuel molar fractions of 0, 0.2, 0.4 and 0.6, at atmospheric pressure and ambient temperature. Two different experimental methods are used. The first method uses a glass tube with visual observation of the flame, whereas the second method uses a closed spherical vessel with a pressure rise criterion to determine whether flame propagation has occurred. In addition to these experiments, the flammability limits are determined numerically. Unsteady planar and spherically expanding flames are calculated with a one-dimensional flame code with the inclusion of radiation heat loss in the optically thin limit. Comparison of the experimental results with the results of the planar flame calculations shows large differences, especially for lean mixtures. These differences increase with increasing hydrogen content in the fuel. Better agreement with the experimental results is found for the spherically expanding flame calculations. A limiting burning velocity of 5 cm/s is found to predict the upper flammability limit determined with the tube method very well, whereas the limiting flame temperature approach was found to give poorer agreement. Further analysis indicates that the neglect of flame front instabilities is the probable cause of the large differences between experimental and numerical results at the lower flammability limit.

  14. The Reseraches and Development Process of Flammable Ice%可燃冰的研究与开发进展

    Institute of Scientific and Technical Information of China (English)

    冯望生; 宋伟宾; 郑箭的; 张维滨; 腾兆健

    2013-01-01

    Flammable ice is commonly known as natural gas hydrate which is regarded as an alternative and clean energy in the 21st century. Flammable ice has a huge potential of development and utilization. The flammable ice's structural features, distribution, mining methods and difficulties in the mining process are comprehensively presented. The prospects for the future development of flammable ice is given finally. A range of problems to the environment will be taken with the development of flammable ice. It will take a long time to achieve industrial-scale and commercial exploitation.%  可燃冰是21世纪公认的替代能和清洁能,开发利用潜力巨大,是天然气水合物的俗称。综合介绍了可燃冰的概况、结构特征、分布情况、开采方法以及开采过程中的难点问题,最后对可燃冰的未来开发前景做了展望,开采可燃冰会给环境带来的一系列问题,要实现工业规模开采和商业化开采还需要一定的时间。

  15. Measurement of volatile organic compounds in human blood.

    OpenAIRE

    Ashley, D L; Bonin, M A; Cardinali, F L; McCraw, J. M.; Wooten, J V

    1996-01-01

    Volatile organic compounds (VOCs) are an important public health problem throughout the developed world. Many important questions remain to be addressed in assessing exposure to these compounds. Because they are ubiquitous and highly volatile, special techniques must be applied in the analytical determination of VOCs. The analytical methodology chosen to measure toxicants in biological materials must be well validated and carefully carried out; poor quality assurance can lead to invalid resul...

  16. Resolve! Version 2.5: Flammable Gas Accident Analysis Tool Acceptance Test Plan and Test Results

    Energy Technology Data Exchange (ETDEWEB)

    LAVENDER, J.C.

    2000-10-17

    RESOLVE! Version 2 .5 is designed to quantify the risk and uncertainty of combustion accidents in double-shell tanks (DSTs) and single-shell tanks (SSTs). The purpose of the acceptance testing is to ensure that all of the options and features of the computer code run; to verify that the calculated results are consistent with each other; and to evaluate the effects of the changes to the parameter values on the frequency and consequence trends associated with flammable gas deflagrations or detonations.

  17. A new group contribution-based model for estimation of lower flammability limit of pure compounds.

    Science.gov (United States)

    Gharagheizi, Farhad

    2009-10-30

    In the present study, a new method is presented for estimation of lower flammability limit (LFL) of pure compounds. This method is based on a combination of a group contribution method and neural networks. The parameters of the model are the occurrences of a new collection of 105 functional groups. Basing on these 105 functional groups, a feed forward neural network is presented to estimate the LFL of pure compounds. The average absolute deviation error obtained over 1057 pure compounds is 4.62%. Therefore, the model is an accurate model and can be used to predict the LFL of a wide range of pure compounds.

  18. ASTM Committee G-4 metals flammability test program - Data and discussion

    Science.gov (United States)

    Stoltzfus, Joel M.; Homa, John M.; Williams, Ralph E.; Benz, Frank J.

    1988-01-01

    Results of metals flammability tests performed on twenty-six metals in the NASA/White Sands Test Facility are discussed together with the test systems. The promoted combustion and ignition characteristics of these metals are described, and the metals are ranked according to their suitability for use in oxygen systems. In general, alloys with high copper and nickel contents and low iron content were found to rank higher than those that had high iron content, while alloys that had high aluminum content were ranked the lowest.

  19. Results of Vapor Space Monitoring of Flammable Gas Watch List Tanks

    Energy Technology Data Exchange (ETDEWEB)

    MCCAIN, D.J.

    2000-09-27

    This report documents the measurement of headspace gas concentrations and monitoring results from the Hanford tanks that have continuous flammable gas monitoring. The systems used to monitor the tanks are Standard Hydrogen Monitoring Systems. Further characterization of the tank off-gases was done with Gas Characterization systems and vapor grab samples. The background concentrations of all tanks are below the action level of 6250 ppm. Other information which can be derived from the measurements (such as generation rate, released rate, and ventilation rate) is also discussed.

  20. Flammability limits in flowing ethene-air-nitrogen mixtures: an experimental study

    OpenAIRE

    Bolk, J.W.; Siccama, N.B.; Westerterp, K.R.

    1996-01-01

    A large pilot plant was constructed to study the upper flammability limit of ethene-air-nitrogen mixtures under conditions of flow. The gas mixtures flowed through an explosion tube with a length of 3.0 m and a diameter of 21 mm. An electrically heated wire was used as ignition source. Experiments were performed at pressures of 5 and 10 bar, with gas temperatures between 25 and 300 °C and with the wire fixed horizontally and vertically. Three different phenomena are observed: negligible react...

  1. Making highly flammable liquid wastes of petrochemical works safe by combustion without burners

    Energy Technology Data Exchange (ETDEWEB)

    Shelygin, B.L.; Bakhirev, V.I.; Gudzyuk, V.L.

    1983-11-01

    At the V.I. Lenin Energy Institute in Ivanov a technological program was implementd for combustion of highly flammable bulk wastes (for example, piperylene fractions) of petrochemical enterprises, with a moisture content of under 10% and mechanical admixtures (particles of catalyst dust) of up to 5%, without the use of burners. In devising the program, the results of mathematical theoretical analysis of pre-igniting preparation of substances to make them safe were utilized as well as the experience acquired in burning petroleum sludge in furnaces with bubbling equipment.

  2. Quaternary Ammonium Ionic Liquids as a Less Flammable Electrolyte for Lithium Batteries

    Institute of Scientific and Technical Information of China (English)

    H.Matsumoto; Z.B.Zhou; H.Sakaebe; K.Tatsumi

    2007-01-01

    1 Results Less-flammability is one of the most valuable properties of ionic liquids (ILs) comprised of perfluoroanions such as BF-4,TFSI-([(CF3SO2)2N]-).Recently,such a unique liquid has been expected to use as an electrolyte in order to improve thermal stability and longevity of a lithium secondary battery,which have been increasingly required for an application especially to an electric vehicle and a hybrid car.We previously reported that PI13[TFSI] (PI13: N-methyl-N-propylpiperidinium) could be used ...

  3. Thermodynamic aspects of heavy metal volatility during utilisation of the energetic and material fraction of waste materials; Schwermetallfluechtigkeit bei der energetischen und stofflichen Verwertung von Abfaellen aus der Sicht der Thermodynamik

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, B.; Starke, A. [TU Bergakademie Freiberg (Germany). Inst. IEC

    1998-09-01

    Co-combustion plants, in which fuel is partly substituted by waste materials, are subject to the 17th BImSchV (Nuisance Control Ordinance) provided that the thermal fraction of 25% is not exceeded. Emission limits are calculated proportionately on the basis of limiting values for emissions from coal power stations (13th BImSchV) and waste incinerators (17th BImSchV). Compared to coal, waste has higher concentrations of heavy metals and halogens, which results in enhanced emissions of heavy metal compounds and chlorides with the flue gas and gasification gas. Plant operators intending to opt for co-combustion must check if the existing flue gas purification system is efficient enough to meet the specifications of the 17th BImSchV. In general, thermodynamic modelling is the most common method of evaluation and optimisation for high-temperature processes of this kind. (orig./SR) [Deutsch] Da bei der Mitverbrennung ein Teil des Brennstoffes durch den Reststoff substituiert wird, unterliegen diese Anlagen der Anteilsregelung nach 17. BImSchV, sofern ein thermischer Anteil von 25% nicht ueberschritten wird. Emissionsgrenzwerte werden anteilig aus den z.B. fuer Kohlekraftwerke gueltigen Grenzwerten nach TA Luft oder 13. BImSchV und denen fuer Abfaelle u.ae. nach 17 BImSchV ermittelt. Der hier betrachtete Reststoff Muell beinhaltet im Vergleich zur Kohle hohe Konzentrationen an Schwermetallen und Halogenen. Dies laesst eine erhoehte Emission von Schwermetallverbindungen und Chloriden mit dem Rauchgas bzw. Vergasungsgas erwarten. Es muss in jedem Fall ueberprueft werden, ob die vorhandene Rauchgasreinigung ausreicht, wenn bei der Mitverbrennung/-vergasung die Emissionsgrenzwerte der 17. BImSchV zur Anwendung kommen. Als Bewertungs- und Optimierungsmethode fuer derartige Hochtemperaturprozesse setzt sich die thermodynamische Modellierung zunehmend durch. (orig./SR)

  4. Option Pricing using Realized Volatility

    DEFF Research Database (Denmark)

    Stentoft, Lars Peter

    In the present paper we suggest to model Realized Volatility, an estimate of daily volatility based on high frequency data, as an Inverse Gaussian distributed variable with time varying mean, and we examine the joint properties of Realized Volatility and asset returns. We derive the appropriate...... benchmark model estimated on return data alone. Hence the paper provides evidence on the value of using high frequency data for option pricing purposes....

  5. Option Pricing using Realized Volatility

    DEFF Research Database (Denmark)

    Stentoft, Lars Peter

    In the present paper we suggest to model Realized Volatility, an estimate of daily volatility based on high frequency data, as an Inverse Gaussian distributed variable with time varying mean, and we examine the joint properties of Realized Volatility and asset returns. We derive the appropriate d...... benchmark model estimated on return data alone. Hence the paper provides evidence on the value of using high frequency data for option pricing purposes....

  6. Volatile signals during pregnancy.

    Science.gov (United States)

    Vaglio, Stefano

    2010-01-01

    Scents play a key role in mediating reproductive interactions in many vertebrates including mammals. Nowadays, several studies indicate that humans seem to use remarkably olfactory communication and are even able to produce and perceive pheromones. Furthermore, over the past several years, it became increasingly clear that pheromone-like chemical signals probably play a role in offspring identification and mother recognition. Recently developed technical procedures (solid-phase microextraction and dynamic headspace extraction) now allow investigators to characterize volatile compounds with high reliability. We analyzed the volatile compounds in sweat patch samples collected from the para-axillary and nipple-areola regions of women during pregnancy and after childbirth. We hypothesized that, at the time of birth and during the first weeks of life, the distinctive olfactory pattern of the para-axillary area is probably useful to newborn babies for recognizing and distinguishing their own mother, whereas the characteristic pattern of the nipple-areola region is probably useful as a guide to nourishment.

  7. Molecular plant volatile communication.

    Science.gov (United States)

    Holopainen, Jarmo K; Blande, James D

    2012-01-01

    Plants produce a wide array of volatile organic compounds (VOCs) which have multiple functions as internal plant hormones (e.g., ethylene, methyl jasmonate and methyl salicylate), in communication with conspecific and heterospecific plants and in communication with organisms of second (herbivores and pollinators) and third (enemies of herbivores) trophic levels. Species specific VOCs normally repel polyphagous herbivores and those specialised on other plant species, but may attract specialist herbivores and their natural enemies, which use VOCs as host location cues. Attraction of predators and parasitoids by VOCs is considered an evolved indirect defence, whereby plants are able to indirectly reduce biotic stress caused by damaging herbivores. In this chapter we review these interactions where VOCs are known to play a crucial role. We then discuss the importance of volatile communication in self and nonself detection. VOCs are suggested to appear in soil ecosystems where distinction of own roots from neighbours roots is essential to optimise root growth, but limited evidence of above-ground plant self-recognition is available.

  8. The flammability limits of lean fuel-air mixtures: thermochemical and kinetic criteria for explosion hazards.

    Science.gov (United States)

    Burgess, D; Hertzberg, M

    1975-01-01

    The present state of knowledge is reviewed concisely in terms of the experimental methods used, the effect of apparatus size, accuracy of data, methods of data presentation, and the sensitivity of the limits to initial temperature and pressure. The heat of combustion per mole of gas mixture at the lean limit is a reliable thermochemical criterion for the flammability of organic fuels with comparable reactivities. The limit calorific value for the heavy paraffins is 11.5 +/- 0.1 kcal mole -1. However, kinetic effects strongly influence this value. Highly reactive fuels (hydrogen, acetylene) require lower energy contents, whereas less reactive fuels (ammonia) require higher values. Hydrogen-starved fuels (carbon monoxide, cyanogen) show marked anomalies and are sensitive to impurities that can provide H-atom chain carriers. These kinetic effects are reflected in the experimentally measurable burning velocity of the fuel. This parameter is a key ingredient in the theory of flammable limits, which is briefly sketched. Five competing processes dissipate power from the combustion wave and quench it at some characteristic limit velocity. The prevalent consensus that the limits are controlled by natural convection is clearly demonstrated, and the complex interplay of kinetics and thermochemistry follows logically therefrom.

  9. Effects of Radiative and Diffusive Transport Processes on Premixed Flames near Flammability Limits

    Science.gov (United States)

    Abbud-Madrid, Angel; Ronney, Paul D.

    1991-01-01

    A study of the mechanisms of flammability limits and the dynamics of flame extinguishment in premixed gas flames is described, a novel feature of which is the use of diluent gases having a wide range of radiative and diffusive transport properties. This feature enables an assessment of the importance of volumetric heat losses and Lewis number effects on these mechanisms. Additionally, effects of flame dynamics and flame front curvature are studied by employing spherically expanding flames obtained in a microgravity environment whereby natural convection is eliminated. New diagnostics include chamber pressure measurements and the first reported species concentration measurements in a microgravity combustion experiment. The limit mechanisms and extinguishment phenomena are found to be strongly influenced by the combined effects of radiant heat loss, Lewis number and flame curvature. Two new and as yet not well understood phenomena are reported: 'double flames' in rich H2-O2-CO2 mixtures and an 'inverse flammability region' in rich C3H8-O2-CO2 mixtures.

  10. Evaluation of lower flammability limits of fuel-air-diluent mixtures using calculated adiabatic flame temperatures.

    Science.gov (United States)

    Vidal, M; Wong, W; Rogers, W J; Mannan, M S

    2006-03-17

    The lower flammability limit (LFL) of a fuel is the minimum composition in air over which a flame can propagate. Calculated adiabatic flame temperatures (CAFT) are a powerful tool to estimate the LFL of gas mixtures. Different CAFT values are used for the estimation of LFL. SuperChems is used by industry to perform flammability calculations under different initial conditions which depends on the selection of a threshold temperature. In this work, the CAFT at the LFL is suggested for mixtures of fuel-air and fuel-air-diluents. These CAFT can be used as the threshold values in SuperChems to calculate the LFL. This paper discusses an approach to evaluate the LFL in the presence of diluents such as N2 and CO2 by an algebraic method and by the application of SuperChems using CAFT as the basis of the calculations. The CAFT for different paraffinic and unsaturated hydrocarbons are presented as well as an average value per family of chemicals.

  11. Estimation of the lower flammability limit of organic compounds as a function of temperature.

    Science.gov (United States)

    Rowley, J R; Rowley, R L; Wilding, W V

    2011-02-15

    A new method of estimating the lower flammability limit (LFL) of general organic compounds is presented. The LFL is predicted at 298 K for gases and the lower temperature limit for solids and liquids from structural contributions and the ideal gas heat of formation of the fuel. The average absolute deviation from more than 500 experimental data points is 10.7%. In a previous study, the widely used modified Burgess-Wheeler law was shown to underestimate the effect of temperature on the lower flammability limit when determined in a large-diameter vessel. An improved version of the modified Burgess-Wheeler law is presented that represents the temperature dependence of LFL data determined in large-diameter vessels more accurately. When the LFL is estimated at increased temperatures using a combination of this model and the proposed structural-contribution method, an average absolute deviation of 3.3% is returned when compared with 65 data points for 17 organic compounds determined in an ASHRAE-style apparatus.

  12. Tests of Flammability of Cotton Fabrics and Expected Skin Burns in Microgravity

    Science.gov (United States)

    Cavanagh, Jane M.; Torvi, David A.; Gabriel, Kamiel S.; Ruff, Gary A.

    2004-01-01

    During a shuttle launch and other portions of space flight, astronauts wear specialized flame resistant clothing. However during most of their missions on board the Space Shuttle or International Space Station, astronauts wear ordinary clothing, such as cotton shirts and pants. As the behaviour of flames is considerably different in microgravity than under earth s gravity, fabrics are expected to burn in a different fashion in microgravity than when tested on earth. There is interest in determining how this change in burning behaviour may affect times to second and third degree burn of human skin, and how the results of standard fabric flammability tests conducted under earth s gravity correlate with the expected fire behaviour of textiles in microgravity. A new experimental apparatus was developed to fit into the Spacecraft Fire Safety Facility (SFSF), which is used on NASA s KC-135 low gravity aircraft. The new apparatus was designed to be similar to the apparatus used in standard vertical flammability tests of fabrics. However, rather than using a laboratory burner, the apparatus uses a hot wire system to ignite 200 mm high by 80 mm wide fabric specimens. Fabric temperatures are measured using thermocouples and/or an infrared imaging system, while flame spread rates are measured using real time observations or video. Heat flux gauges are placed between 7 and 13 mm away from the fabric specimen, so that heat fluxes from the burning fabric to the skin can be estimated, along with predicted times required to produce skin burns.

  13. Swelling of organoclays in styrene. Effect on flammability in polystyrene nanocomposites

    Directory of Open Access Journals (Sweden)

    2010-08-01

    Full Text Available In this work the effect of the compatibility between organoclays and styrene on the flammability of polystyrene/clay nanocomposites obtained through in situ incorporation was investigated. The reactions were carried out by bulk polymerization. The compatibility between organoclays and styrene was inferred from swelling of the organoclay in styrene. The nanocomposites were characterized by X-ray diffraction and Transmission Electron Microscopy. The heat release rate was obtained by Cone Calorimeter and the nanocomposites were tested by UL94 horizontal burn test. Results showed that intercalated and partially exfoliated polystyrene/clay nanocomposites were obtained depending on the swelling behavior of the organoclay in styrene. The nanocomposites submitted to UL94 burning test presented a burning rate faster than the virgin polystyrene (PS, however an increase of the decomposition temperature and an accentuated decrease on the peak of heat release of the nanocomposites were also observed compared to virgin PS. These results indicate that PS/clay nanocomposites, either intercalated or partially exfoliated, reduced the flammability approximately by the same extent, although reduced the ignition resistance of the PS.

  14. Development of organic non-flammable spacecraft potting, encapsulating and conformal coating compounds

    Science.gov (United States)

    Lieberman, S. L.

    1971-01-01

    The overall program objective was to develop a flexible compound which not only functioned in a manned aerospace environment as an effective electrical insulation, but whose flammability characteristics in 16.5 psia, 60% oxygen/40% nitrogen were evidenced by rapid self-extinguishment and minimal thermal (pyrolysis) degradation. The following polymeric matrices were examined in depth: fluoroelastomers, modified fluoroelastomers, silicone RTV's, and modified silicone and fluorosilicone RTV's. Almost none of these systems burned in air, but all burned in 6.2 psia oxygen. Inorganic, organic, and inorganic/organic additives were evaluated in conjunction with these polymers in order to achieve the required survival in the 16.5 psia 60/40 environment. Depending upon formulations, it was possible to achieve nonflammable products when tested in the 1/4 in. x 1/4 in. x 1 in. configuration, even up to and including 16.5 psia oxygen. However, in order to assure this level of flame resistance, it was found necessary to heavily load the matrix with the additives. This resulted in a significant reduction in mechanical properties and large increases in viscosities. Optimization of formulations to obtain a suitable balance between these properties and flammability resistance led to the final selection of Formulation 387 as the primary system.

  15. An approximate-reasoning-based method for screening high-level waste tanks for flammable gas

    Energy Technology Data Exchange (ETDEWEB)

    Eisenhawer, S.W.; Bott, T.F.; Smith, R.E.

    1998-07-01

    The in situ retention of flammable gas produced by radiolysis and thermal decomposition in high-level waste can pose a safety problem if the gases are released episodically into the dome space of a storage tank. Screening efforts at Hanford have been directed at identifying tanks in which this situation could exist. Problems encountered in screening motivated an effort to develop an improved screening methodology. Approximate reasoning (AR) is a formalism designed to emulate the kinds of complex judgments made by subject matter experts. It uses inductive logic structures to build a sequence of forward-chaining inferences about a subject. AR models incorporate natural language expressions known as linguistic variables to represent evidence. The use of fuzzy sets to represent these variables mathematically makes it practical to evaluate quantitative and qualitative information consistently. The authors performed a pilot study to investigate the utility of AR for flammable gas screening. They found that the effort to implement such a model was acceptable and that computational requirements were reasonable. The preliminary results showed that important judgments about the validity of observational data and the predictive power of models could be made. These results give new insights into the problems observed in previous screening efforts.

  16. Structure-flammability relationship study of phosphoester dimers by MLR and PLS

    Directory of Open Access Journals (Sweden)

    Luminita Crisan

    Full Text Available Abstract Polyphosphonates and polyphosphates having good flame retardancy represent an important class of organophosphorus based polymer additives. In this analysis the flammability of 28 previously synthesized polyphosphoesters, modelled as dimmers, was explored using the multiple linear regression (MLR and Partial Least Square (PLS methodology. The statistical quality of the final MLR and PLS models was estimated using the following parameters: the squared correlation coefficient ( r t r a i n i n g 2= 0.917 and 0.976, the training root-mean-square errors (RMSEtr = 0.029 and 0.016 and the leave-seven-out cross-validation correlation coefficient ( q L 7 O 2= 0.748 and 0.881, respectively. External validation was checked for a test set of seven compounds using several criteria. The MLR models had somewhat inferior fitting results. The final MLR and PLS models can be used for the estimation of limiting oxygen index (LOI values of new polyphosphoester structures. The presence of phosphonate groups and increasing molecular branching in an isomeric series favour the dimer flammability.

  17. Mechanical, Thermal Degradation, and Flammability Studies on Surface Modified Sisal Fiber Reinforced Recycled Polypropylene Composites

    Directory of Open Access Journals (Sweden)

    Arun Kumar Gupta

    2012-01-01

    Full Text Available The effect of surface treated sisal fiber on the mechanical, thermal, flammability, and morphological properties of sisal fiber (SF reinforced recycled polypropylene (RPP composites was investigated. The surface of sisal fiber was modified with different chemical reagent such as silane, glycidyl methacrylate (GMA, and O-hydroxybenzene diazonium chloride (OBDC to improve the compatibility with the matrix polymer. The experimental results revealed an improvement in the tensile strength to 11%, 20%, and 31.36% and impact strength to 78.72%, 77%, and 81% for silane, GMA, and OBDC treated sisal fiber reinforced recycled Polypropylene (RPP/SF composites, respectively, as compared to RPP. The thermogravimetric analysis (TGA, differential scanning calorimeter (DSC, and heat deflection temperature (HDT results revealed improved thermal stability as compared with RPP. The flammability behaviour of silane, GMA, and OBDC treated SF/RPP composites was studied by the horizontal burning rate by UL-94. The morphological analysis through scanning electron micrograph (SEM supports improves surface interaction between fiber surface and polymer matrix.

  18. Structure-flammability relationship study of phosphoester dimers by MLR and PLS

    Directory of Open Access Journals (Sweden)

    Luminita Crisan

    2016-01-01

    Full Text Available Abstract Polyphosphonates and polyphosphates having good flame retardancy represent an important class of organophosphorus based polymer additives. In this analysis the flammability of 28 previously synthesized polyphosphoesters, modelled as dimmers, was explored using the multiple linear regression (MLR and Partial Least Square (PLS methodology. The statistical quality of the final MLR and PLS models was estimated using the following parameters: the squared correlation coefficient ( r t r a i n i n g 2= 0.917 and 0.976, the training root-mean-square errors (RMSEtr = 0.029 and 0.016 and the leave-seven-out cross-validation correlation coefficient ( q L 7 O 2= 0.748 and 0.881, respectively. External validation was checked for a test set of seven compounds using several criteria. The MLR models had somewhat inferior fitting results. The final MLR and PLS models can be used for the estimation of limiting oxygen index (LOI values of new polyphosphoester structures. The presence of phosphonate groups and increasing molecular branching in an isomeric series favour the dimer flammability.

  19. Volatile organic emissions from the distillation and pyrolysis of vegetation

    Directory of Open Access Journals (Sweden)

    J. P. Greenberg

    2006-01-01

    Full Text Available Leaf and woody plant tissue (Pinus ponderosa, Eucalyptus saligna, Quercus gambelli, Saccharum officinarum and Oriza sativa were heated from 30 to 300°C and volatile organic compound (VOC emissions were identified and quantified. Major VOC emissions were mostly oxygenated and included acetic acid, furylaldehyde, acetol, pyrazine, terpenes, 2,3-butadione, phenol and methanol, as well as smaller emissions of furan, acetone, acetaldehyde, acetonitrile and benzaldehyde. Total VOC emissions from distillation and pyrolysis were on the order of 10 gC/kgC dry weight of vegetation, as much as 33% and 44% of CO2 emissions (gC(VOC/gC(CO2 measured during the same experiments, in air and nitrogen atmospheres, respectively. The emissions are similar in identity and quantity to those from smoldering combustion of woody tissue and of different character than those evolved during flaming combustion. VOC emissions from the distillation of pools and endothermic pyrolysis under low turbulence conditions may produce flammable concentrations near leaves and may facilitate the propagation of wildfires. VOC emissions from charcoal production are also related to distillation and pyrolysis; the emissions of the highly reactive VOCs from production are as large as the carbon monoxide emissions.

  20. Hygroscopic behavior of partially volatilized coastal marine aerosols using the volatilization and humidification tandem differential mobility analyzer technique

    Science.gov (United States)

    Johnson, G. R.; Ristovski, Z. D.; D'Anna, B.; Morawska, L.

    2005-10-01

    Coastal marine nucleation, Aitken, and accumulation mode aerosol particles with back trajectories indicative of marine origin were examined using a volatilization and humidification tandem differential mobility analyzer (VHTDMA) to reveal the volatilization temperatures of the various component species. The diameter hygroscopic growth factors of the residue particles were continually examined throughout the volatilization process. In each of the three modes the dominant particle type appeared to be composed of the same four physicochemically distinct species though in different ratios. These species exhibited volatility and hygroscopic behavior consistent with combinations of a volatile organic species, sulfuric acid, ammonium sulfate or bisulfate, iodine oxide, and an insoluble nonvolatile residue. The Aitken and accumulation mode aerosols contain large fractions of the insoluble, volatile, organic-like material, and the volatilization of this species results in a distinct increase in the water volume uptake of the particles. Of the four distinct species, only the sulfuric acid-like species constituted an increasing volume fraction with decreasing particle size. This finding indicates that nucleation mode particles constitute an acidic seed and as such would undergo acid-catalyzed secondary organic aerosol growth at a faster rate. The lack of a nonvolatile hygroscopic residue consistent with sea salt in these particles implies that the aerosolization of seawater is not the dominant production mechanism for these submicrometer coastal marine aerosols.

  1. Potential of derived lunar volatiles for life support

    Science.gov (United States)

    Bula, R. J.; Wittenberg, L. J.; Tibbitts, T. W.; Kulcinski, G. L.

    1992-01-01

    The lunar regolith contains small quantities of solar wind implanted volatile compounds that have vital, basic uses for maintaining life support systems of lunar or space settlements. Recent proposals to utilize the helium-3 isotope (He-3) derived from the lunar regolith as a fuel for fusion reactors would result in the availability of large quantities of other lunar volatile compounds. The quantities obtained would provide the annual life support replacement requirements of 1150 to 23,000 inhabitants per ton of He-3 recovered, depending on the volatile compound. Utilization of the lunar volatile compounds for life support depends on the costs, in terms of materials and energy, associated with their extraction from the lunar regolith as compared to the delivery costs of these compounds from Earth resources. Considering today's conservative estimated transportation costs ($10,000 dollars per kilogram) and regolith mining costs ($5 dollars per ton), the life support replacement requirements could be more economically supplied by recovering the lunar volatile compounds than transporting these materials from Earth resources, even before He-3 will be utilized as a fusion fuel. In addition, availability of lunar volatile compounds could have a significant cost impact on maintaining the life support systems of the space station and a Mars base.

  2. Rechargeable lithium battery using non-flammable electrolyte based on tetraethylene glycol dimethyl ether and olivine cathodes

    Science.gov (United States)

    Di Lecce, Daniele; Carbone, Lorenzo; Gancitano, Vincenzo; Hassoun, Jusef

    2016-12-01

    We propose lithium metal cells employing LiCF3SO3-tetraethylene glycol dimethy ether (TEGDME) electrolyte solution with LiFePO4 and LiMn0.5Fe0.5PO4 cathodes. The electrolyte is selected due to its non-flammability, herein demonstrated, and considered as a key requirement for application cells employing high energy lithium metal anode. The selected olivine cathodes, i.e., stable materials prepared by solvothermal pathway, have regular submicrometrical morphology suitable for cell operation and homogeneous composition, as confirmed by electron microscopy and energy dispersive X-ray spectroscopy. The electrochemical tests reveal promising cycling performances in terms of delivered capacity, stability and rate capability. The Li/LiCF3SO3-TEGDME/LiFePO4 cell operates at 3.5 V with capacity ranging from 150 mAh g-1 at C/10 to 110 mAh g-1 at 2C, while the Li/LiCF3SO3-TEGDME/LiFe0.5Mn0.5PO4 cell performs following two plateaus at 4.1 V and 3.5 V with capacity ranging from 160 mAh g-1 at C/10 to 75 mAh g-1 at 2C. Hence, the results demonstrate the suitability of TEGDME-based electrolytes in combination with LiFePO4 and LiFe0.5Mn0.5PO4 cathodes for high performances lithium battery.

  3. Consistent ranking of volatility models

    DEFF Research Database (Denmark)

    Hansen, Peter Reinhard; Lunde, Asger

    2006-01-01

    We show that the empirical ranking of volatility models can be inconsistent for the true ranking if the evaluation is based on a proxy for the population measure of volatility. For example, the substitution of a squared return for the conditional variance in the evaluation of ARCH-type models can...

  4. Political institutions and economic volatility

    NARCIS (Netherlands)

    Klomp, Jeroen; de Haan, Jakob

    2009-01-01

    We examine the effect of political 'institutions' on economic growth volatility, using data from more than 100 countries over the period 1960 to 2005, taking into account various control variables as suggested in previous studies. Our indicator of volatility is the relative standard deviation of the

  5. Emerging non-volatile memories

    CERN Document Server

    Hong, Seungbum; Wouters, Dirk

    2014-01-01

    This book is an introduction to the fundamentals of emerging non-volatile memories and provides an overview of future trends in the field. Readers will find coverage of seven important memory technologies, including Ferroelectric Random Access Memory (FeRAM), Ferromagnetic RAM (FMRAM), Multiferroic RAM (MFRAM), Phase-Change Memories (PCM), Oxide-based Resistive RAM (RRAM), Probe Storage, and Polymer Memories. Chapters are structured to reflect diffusions and clashes between different topics. Emerging Non-Volatile Memories is an ideal book for graduate students, faculty, and professionals working in the area of non-volatile memory. This book also: Covers key memory technologies, including Ferroelectric Random Access Memory (FeRAM), Ferromagnetic RAM (FMRAM), and Multiferroic RAM (MFRAM), among others. Provides an overview of non-volatile memory fundamentals. Broadens readers' understanding of future trends in non-volatile memories.

  6. Governmentally amplified output volatility

    Science.gov (United States)

    Funashima, Yoshito

    2016-11-01

    Predominant government behavior is decomposed by frequency into several periodic components: updating cycles of infrastructure, Kuznets cycles, fiscal policy over business cycles, and election cycles. Little is known, however, about the theoretical impact of such cyclical behavior in public finance on output fluctuations. Based on a standard neoclassical growth model, this study intends to examine the frequency at which public investment cycles are relevant to output fluctuations. We find an inverted U-shaped relationship between output volatility and length of cycle in public investment. This implies that periodic behavior in public investment at a certain frequency range can cause aggravated output resonance. Moreover, we present an empirical analysis to test the theoretical implication, using the U.S. data in the period from 1968 to 2015. The empirical results suggest that such resonance phenomena change from low to high frequency.

  7. Volatility Exposure for Strategic Asset Allocation

    OpenAIRE

    Briere, Marie; Burgues, Alexandre; Signori, Ombretta

    2010-01-01

    The authors examine the advantages of incorporating strategic exposure to equity volatility into the investment opportunity set of a long-term equity investor. They consider two standard volatility investments: implied volatility and volatility risk premium strategies. An analytical framework, which offers pragmatic solutions for long-term investors who seek exposure to volatility, is used to calibrate and assess the risk-return profiles of portfolios. The benefit of volatility exposure for a...

  8. Reduced Heart Rate Volatility

    Science.gov (United States)

    Grogan, Eric L.; Morris, John A.; Norris, Patrick R.; France, Daniel J.; Ozdas, Asli; Stiles, Renée A.; Harris, Paul A.; Dawant, Benoit M.; Speroff, Theodore

    2004-01-01

    Objective: To determine if using dense data capture to measure heart rate volatility (standard deviation) measured in 5-minute intervals predicts death. Background: Fundamental approaches to assessing vital signs in the critically ill have changed little since the early 1900s. Our prior work in this area has demonstrated the utility of densely sampled data and, in particular, heart rate volatility over the entire patient stay, for predicting death and prolonged ventilation. Methods: Approximately 120 million heart rate data points were prospectively collected and archived from 1316 trauma ICU patients over 30 months. Data were sampled every 1 to 4 seconds, stored in a relational database, linked to outcome data, and de-identified. HR standard deviation was continuously computed over 5-minute intervals (CVRD, cardiac volatility–related dysfunction). Logistic regression models incorporating age and injury severity score were developed on a test set of patients (N = 923), and prospectively analyzed in a distinct validation set (N = 393) for the first 24 hours of ICU data. Results: Distribution of CVRD varied by survival in the test set. Prospective evaluation of the model in the validation set gave an area in the receiver operating curve of 0.81 with a sensitivity and specificity of 70.1 and 80.0, respectively. CVRD predict death as early as 24 hours in the validation set. Conclusions: CVRD identifies a subgroup of patients with a high probability of dying. Death is predicted within first 24 hours of stay. We hypothesize CVRD is a surrogate for autonomic nervous system dysfunction. PMID:15319726

  9. Price Volatility Spillover in Agricultural Markets: An Examination of U.S. Catfish Markets

    OpenAIRE

    Buguk, Cumhur; Hudson, Darren; Hanson, Terrill R.

    2003-01-01

    Price volatility spillovers in the U.S. catfish supply chain are analyzed based on monthly price data from 1980 through 2000 for catfish feed, its ingredients, and farm- and wholesale-level catfish. The exponential generalized autoregressive conditional heteroskedasticity (EGARCH) model was used to test univariate volatility spillovers for prices in the supply chain. Strong price volatility spillover from feeding material (corn, soybeans, menhaden) to catfish feed and farm- and wholesale-leve...

  10. Report on the handling of safety information concerning flammable gases and ferrocyanide at the Hanford waste tanks

    Energy Technology Data Exchange (ETDEWEB)

    1990-07-01

    This report discusses concerns safety issues, and management at Hanford Tank Farm. Concerns center on the issue of flammable gas generation which could ignite, and on possible exothermic reactions of ferrocyanide compounds which were added to single shell tanks in the 1950's. It is believed that information concerning these issues has been mis-handled and the problems poorly managed. (CBS)

  11. Estimation of Flammability Limits of Selected Fluorocarbons with F(sub 2) and CIF(sub3)

    Energy Technology Data Exchange (ETDEWEB)

    Trowbridge, L.D.

    1999-09-01

    During gaseous diffusion plant operations, conditions leading to the formation of flammable gas mixtures may occasionally arise. Currently, these could consist of the evaporative coolant CFC-114 and fluorinating agents such as F(sub 2) and CIF(sub 3). Replacement of CFC-114 with non-ozone-depleting substitutes such as c-C(sub 4)F(sub 8) and C(sub 4)F(sub 10) is planned. Consequently, in the future, these too must be considered potential ''fuels'' in flammable gas mixtures. Two questions of practical interest arise: (1) can a particular mixture sustain and propagate a flame if ignited, and (2) what is the maximum pressure that can be generated by the burning (and possibly exploding) gas mixture, should ignite? Experimental data on these systems are limited. To assist in answering these questions, a literature search for relevant data was conducted, and mathematical models were developed to serve as tools for predicting potential detonation pressures and estimating (based on empirical correlations between gas mixture thermodynamics and flammability for known systems) the composition limits of flammability for these systems. The models described and documented in this report are enhanced versions of similar models developed in 1992.

  12. Methods development for measuring and classifying flammability/combustibility of refrigerants. Interim report, Task 1 -- Annotated bibliography and summary

    Energy Technology Data Exchange (ETDEWEB)

    Heinonen, E.W.; Tapscott, R.E. [New Mexico Univ., Albuquerque, NM (United States). Center for Global Enviromental Technology

    1994-06-01

    For Task 1 of the flammable refrigerant methods development contract, NMERI performed a literature search to identify references on the flammability of refrigerants. A database to store a bibliographic record of the literature search was then developed. This database is contained in the Microsoft Access{reg_sign} relational database management system for Windows{trademark}. Searches for applicable sources were made on-line using the STN{reg_sign} scientific and technical network; off-line using the National Technical Information Service (NTIS) database; WorldCat CD-rom database; the University of New Mexico library search; the Air-Conditioning and Refrigeration institute (ARI) Refrigerant Database; and personal contacts. Three specific areas were searched: refrigerant properties, flammability test methods, and ignition technology. Many of the articles retrieved fall into multiple categories. Ignition technology was included as a separate category because of the importance of the ignition process to flammability and the vast amount of information available on ignition of gaseous fuels, especially hydrocarbons. Over 90 separate references have been entered into the database. Two separate report formats have been developed to display the results of the literature search. Appendix B is the short report format--without abstract, while Appendix C is the long format--with abstract.

  13. Materials

    Science.gov (United States)

    Glaessgen, Edward H.; Schoeppner, Gregory A.

    2006-01-01

    NASA Langley Research Center has successfully developed an electron beam freeform fabrication (EBF3) process, a rapid metal deposition process that works efficiently with a variety of weldable alloys. The EBF3 process can be used to build a complex, unitized part in a layer-additive fashion, although the more immediate payoff is for use as a manufacturing process for adding details to components fabricated from simplified castings and forgings or plate products. The EBF3 process produces structural metallic parts with strengths comparable to that of wrought product forms and has been demonstrated on aluminum, titanium, and nickel-based alloys to date. The EBF3 process introduces metal wire feedstock into a molten pool that is created and sustained using a focused electron beam in a vacuum environment. Operation in a vacuum ensures a clean process environment and eliminates the need for a consumable shield gas. Advanced metal manufacturing methods such as EBF3 are being explored for fabrication and repair of aerospace structures, offering potential for improvements in cost, weight, and performance to enhance mission success for aircraft, launch vehicles, and spacecraft. Near-term applications of the EBF3 process are most likely to be implemented for cost reduction and lead time reduction through addition of details onto simplified preforms (casting or forging). This is particularly attractive for components with protruding details that would require a significantly large volume of material to be machined away from an oversized forging, offering significant reductions to the buy-to-fly ratio. Future far-term applications promise improved structural efficiency through reduced weight and improved performance by exploiting the layer-additive nature of the EBF3 process to fabricate tailored unitized structures with functionally graded microstructures and compositions.

  14. Subduction and volatile recycling in Earth's mantle

    Science.gov (United States)

    King, S. D.; Ita, J. J.; Staudigel, H.

    1994-01-01

    The subduction of water and other volatiles into the mantle from oceanic sediments and altered oceanic crust is the major source of volatile recycling in the mantle. Until now, the geotherms that have been used to estimate the amount of volatiles that are recycled at subduction zones have been produced using the hypothesis that the slab is rigid and undergoes no internal deformation. On the other hand, most fluid dynamical mantle flow calculations assume that the slab has no greater strength than the surrounding mantle. Both of these views are inconsistent with laboratory work on the deformation of mantle minerals at high pressures. We consider the effects of the strength of the slab using two-dimensional calculations of a slab-like thermal downwelling with an endothermic phase change. Because the rheology and composition of subducting slabs are uncertain, we consider a range of Clapeyron slopes which bound current laboratory estimates of the spinel to perovskite plus magnesiowustite phase transition and simple temperature-dependent rheologies based on an Arrhenius law diffusion mechanism. In uniform viscosity convection models, subducted material piles up above the phase change until the pile becomes gravitationally unstable and sinks into the lower mantle (the avalanche). Strong slabs moderate the 'catastrophic' effects of the instabilities seen in many constant-viscosity convection calculations; however, even in the strongest slabs we consider, there is some retardation of the slab descent due to the presence of the phase change.

  15. Responding to Terrorist Incidents in Your Community: Flammable-Liquid Fire Fighting Techniques for Municipal and Rural Firefighters

    Energy Technology Data Exchange (ETDEWEB)

    Denise Baclawski

    2010-03-08

    The University of Nevada, Reno Fire Science Academy (FSA) applied for grant funding to develop and deliver programs for municipal, rural, and volunteer firefighters. The FSA specializes in preparing responders for a variety of emergency events, including flammable liquid fires resulting from accidents, intentional acts, or natural disasters. Live fire training on full scale burnable props is the hallmark of FSA training, allowing responders to practice critical skills in a realistic, yet safe environment. Unfortunately, flammable liquid live fire training is often not accessible to municipal, rural, or volunteer firefighters due to limited department training budgets, even though most department personnel will be exposed to flammable liquid fire incidents during the course of their careers. In response to this training need, the FSA developed a course during the first year of the grant (Year One), Responding to Terrorist Incidents in Your Community: Flammable-Liquid Fire Fighting Techniques for Municipal and Rural Firefighters. During the three years of the grant, a total of 2,029 emergency responders received this training. In Year Three, two new courses, a train-the-trainer for Responding to Terrorist Incidents in Your Community and Management of Large-Scale Disasters for Public Officials were developed and pilot tested during the Real-World Disaster Management Conference held at the FSA in June of 2007. Two research projects were conducted during Years Two and Three. The first, conducted over a two year period, evaluated student surveys regarding the value of the flammable liquids training received. The second was a needs assessment conducted for rural Nevada. Both projects provided important feedback and a basis for curricula development and improvements.

  16. Data Observations on Double Shell Tank (DST) Flammable Gas Watch List Tank Behavior

    Energy Technology Data Exchange (ETDEWEB)

    HEDENGREN, D.C.

    2000-09-28

    This report provides the data from the retained gas sampler, void fraction instrument, ball rheometer, standard hydrogen monitoring system, and other tank data pertinent to gas retention and release behavior in the waste stored in double-shelled Flammable Gas Watch List tanks at Hanford. These include tanks 241-AN-103,241-AN-104, 241-AN-105, 241-AW-101, 241-SY-101, and 241-SY-103. The tanks and the waste they contain are described in terms of fill history and chemistry. The results of mixer pump operation and recent waste transfers and back-dilution in SY-101 are also described. In-situ measurement and monitoring systems are described and the data are summarized under the categories of thermal behavior, waste configuration and properties, gas generation and composition, gas retention and historical gas release behavior.

  17. Influence of dispersion degree of water drops on efficiency of extinguishing of flammable liquids

    Directory of Open Access Journals (Sweden)

    Korolchenko Dmitriy

    2016-01-01

    Full Text Available Depending on the size of water drops, process of fire extinguishing is focused either in a zone of combustion or on a burning liquid surface. This article considers two alternate solutions of a heat balance equation. The first solution allows us to trace decrease of temperature of a flammable liquid (FL surface to a temperature lower than fuel flash point at which combustion is stopped. And the second solution allows us to analyze decrease of burnout rate to a negligible value at which steam-air mixture becomes nonflammable. As a result of solve of a heat balance equation it was made the following conclusion: water drops which size is equal to 100 μm will completely evaporate in a zone of combustion with extent of 1 m if the flying speed of drops is even 16 mps (acc. to Stokes v = 3 mps; whereas drops of larger size will evaporate only partially.

  18. Flammability of polypropylene/organoclay nanocomposites; Inflamabilidade de nanocompositos de polipropileno/argila organofilica

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Tatianny Soares; Barbosa, Renata, E-mail: tsaeng3@yahoo.com.br [Universidade Federal do Piaui (UFPI), Teresina (Brazil); Carvalho, Laura Hecker de [Universidade Federal de Campina Grande (UFCG), PB (Brazil); Canedo, Eduardo Luis [Instituto de Tecnologia de Pernambuco, Recife (Brazil)

    2014-11-01

    The flammabilities of nanocomposites made with three polypropylene grades (homo and copolymers) with 5 wt % of organoclay (Cloisite 20A), 5 or 15 wt % of maleated polypropylene as compatibilizer, and 0, 0.5 or 1 wt % of cis-13-docosenamide (Erucamide) as co-intercalant, were studied using the horizontal burning test UL94HB. Masterbatches prepared in an internal mixer were diluted in the polypropylene matrix using a corotating twin-screw extruder, with different screw configurations and operating at 240 or 480 rpm. Results indicate that the high burning rate of the composites was not affected by the processing conditions. For all formulations was observed a significant reduction in smoke release, lack of dripping and the formation of a char surface layer, that protected the core of the samples. (author)

  19. Flammability properties of polypropylene containing montmorillonite and some of silicon compounds

    Directory of Open Access Journals (Sweden)

    A.A. Younis

    2017-03-01

    Full Text Available New polypropylene (PP blends were prepared using phenyltrimethoxysilane (PTMS, glycidoxypropyltrimethoxysilane (GPTMS and potassium-montmorillonite (K-MMT. Polymers A (K-MMT/PTMS, B (MMT/GPTMS and C (modified-MMT were prepared using sol-gel technique then incorporated in the PP matrix by different concentrations. Fourier transform infrared spectroscopy (FTIR, thermogravimetric analysis (TGA, and differential scanning calorimeter (DSC were used to investigate the structure and thermal stability. The mechanical properties (tensile strength/TS and elongation/% were measured. The flame-retardant properties of the unblended and blended (PP/A, PP/B and PP/C were estimated by limiting oxygen index (LOI, flame chamber (UL/94 and oxygen bomb calorimeter (OBC tests, whereas the thermal stabilities were investigated using TGA were carried flammability out to detect the properties of the blended PP.

  20. Experimental Studies on the Flammability and Fire Hazards of Photovoltaic Modules

    Directory of Open Access Journals (Sweden)

    Hong-Yun Yang

    2015-07-01

    Full Text Available Many of the photovoltaic (PV systems on buildings are of sufficiently high voltages, with potential to cause or promote fires. However, research about photovoltaic fires is insufficient. This paper focuses on the flammability and fire hazards of photovoltaic modules. Bench-scale experiments based on polycrystalline silicon PV modules have been conducted using a cone calorimeter. Several parameters including ignition time (tig, mass loss, heat release rate (HRR, carbon monoxide (CO and carbon dioxide (CO2 concentration, were investigated. The fire behaviours, fire hazards and toxicity of gases released by PV modules are assessed based on experimental results. The results show that PV modules under tests are inflammable with the critical heat flux of 26 kW/m2. This work will lead to better understanding on photovoltaic fires and how to help authorities determine the appropriate fire safety provisions for controlling photovoltaic fires.

  1. A highly conductive, non-flammable polymer–nanoparticle hybrid electrolyte

    KAUST Repository

    Agrawal, Akanksha

    2015-01-01

    © 2015 The Royal Society of Chemistry. We report on the physical properties of lithium-ion conducting nanoparticle-polymer hybrid electrolytes created by dispersing bidisperse mixtures of polyethylene glycol (PEG)-functionalized silica nanoparticles in an aprotic liquid host. At high particle contents, we find that the ionic conductivity is a non-monotonic function of the fraction of larger particles xL in the mixtures, and that for the nearly symmetric case xL ≈ 0.5 (i.e. equal volume fraction of small and large particles), the room temperature ionic conductivity is nearly ten-times larger than in similar nanoparticle hybrid electrolytes comprised of the pure small (xL ≈ 0) or large (xL ≈ 1) particle components. Complementary trends are seen in the activation energy for ion migration and effective tortuosity of the electrolytes, which both exhibit minima near xL ≈ 0.5. Characterization of the electrolytes by dynamic rheology reveals that the maximum conductivity coincides with a distinct transition in soft glassy properties from a jammed to partially jammed and back to jammed state, as the fraction of large particles is increased from 0 to 1. This finding implies that the conductivity enhancement arises from purely entropic loss of correlation between nanoparticle centers arising from particle size dispersity. As a consequence of these physics, it is now possible to create hybrid electrolytes with MPa elastic moduli and mS cm-1 ionic conductivity levels at room temperature using common aprotic liquid media as the electrolyte solvent. Remarkably, we also find that even in highly flammable liquid media, the bidisperse nanoparticle hybrid electrolytes can be formulated to exhibit low or no flammability without compromising their favorable room temperature ionic conductivity and mechanical properties.

  2. Titanium Dioxide Volatility in High Temperature Water Vapor

    Science.gov (United States)

    Nguyen, QynhGiao N.

    2008-01-01

    Titanium (Ti) containing materials are of high interest to the aerospace industry due to its high temperature capability, strength, and light weight. As with most metals an exterior oxide layer naturally exists in environments that contain oxygen (i.e. air). At high temperatures, water vapor plays a key role in the volatility of materials including oxide surfaces. This study will evaluate cold pressed titanium dioxide (TiO2) powder pellets at a temperature range of 1400 C - 1200 C in water containing environments to determine the volatile hydroxyl species using the transpiration method. The water content ranged from 0-76 mole% and the oxygen content range was 0-100 mole % during the 20-250 hour exposure times. Preliminary results indicate that oxygen is not a key contributor at these temperatures and the following reaction is the primary volatile equation for all three temperatures: TiO2 (s) + H2O (g) = TiO(OH)2 (g).

  3. 49 CFR 192.735 - Compressor stations: Storage of combustible materials.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Compressor stations: Storage of combustible... SAFETY TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Maintenance § 192.735 Compressor stations: Storage of combustible materials. (a) Flammable or combustible materials...

  4. Stochastic volatility and stochastic leverage

    DEFF Research Database (Denmark)

    Veraart, Almut; Veraart, Luitgard A. M.

    This paper proposes the new concept of stochastic leverage in stochastic volatility models. Stochastic leverage refers to a stochastic process which replaces the classical constant correlation parameter between the asset return and the stochastic volatility process. We provide a systematic...... treatment of stochastic leverage and propose to model the stochastic leverage effect explicitly, e.g. by means of a linear transformation of a Jacobi process. Such models are both analytically tractable and allow for a direct economic interpretation. In particular, we propose two new stochastic volatility...... models which allow for a stochastic leverage effect: the generalised Heston model and the generalised Barndorff-Nielsen & Shephard model. We investigate the impact of a stochastic leverage effect in the risk neutral world by focusing on implied volatilities generated by option prices derived from our new...

  5. On forecasting Exchange Rate Volatility.

    OpenAIRE

    Hafner, Christian

    2003-01-01

    In an efficient market, foreign exchange rates have to guarantee absence of triangular arbitrage. This note shows that the no-arbitrage condition can be exploited for forecasting the volatility of a single rate by using the information contained in the other rates. Linearly transforming the volatility forecasts of a bivariate model is shown to be more efficient than using a univariate model for the cross-rate.

  6. Head-space Gas Chromatography Comparison of Volatile Organic Compounds from Packing Materials and Packaged Lycium barbarum Pieces%包装材料与枸杞子饮片中挥发性有机物的顶空气相色谱比较

    Institute of Scientific and Technical Information of China (English)

    王晓宇; 银玲; 刘友平

    2013-01-01

    Objective: To compare volatile organic compounds in nine samples including three blank packaging materials ( composite membrane of polyethylene and aluminum foil, polyethylene plastic membrane, leather condensate membrane paper) , these three kinds of materials have packaged and Lycium barbarum pieces have packaged for 12 months using these three kinds of packaged materials. Method: Component analysis of volatile organic compounds in these nine samples was determined by head-space gas chromatography, the relative content of each compound was gained by area normalization method. Result: Vvolatile organic compounds in each sample were mainly oxidation terpenoids, aldoketones and fatty acids compounds, among them, blank polyethylene bag peculiarly included volatile dissolvent (ethanol and acetone) ; Isopropyl alcohol and n-pentanol were only being in leather condensate membrane paper; polyethylene bag and leather condensate membrane paper which packaged L. barbarum pieces for 12 months all contained benzaldehyde. Three blank packaging material all contained BHT which was additive antioxidant usually used in plastic packaging materials, only blank leather condensate membrane bag contained BHA which was additive antioxidant usually used in plastic packaging materials; furfuraldehyde was the main ingredient in L. barbarum which packaged for 12 months. Conclusion: Compositions and relative content of L. barbarum pieces using different packing materials were different, it showed that packaging materials had an important effect on volatile organic compounds in the pieces.%目的:对3种空白包装材料(聚乙烯铝箔复合膜、聚乙烯塑料膜、牛皮凝膜纸)、3种已包装材料及采用3种包装材料包装12月的枸杞子饮片共9个样品中的挥发性有机物进行比较研究.方法:采用顶空气相色谱法对9个样品中的挥发性有机物进行成分分析,用面积归一化法获得各化合物的相对含量.结果:各样品中挥发性有机

  7. Shock-induced volatile loss from a carbonaceous chondrite Implications for planetary accretion

    Science.gov (United States)

    Tyburczy, James A.; Frisch, Benjamin; Ahrens, Thomas J.

    1986-01-01

    Solid recovery impact-induced volatile loss experiments on the Murchison C2M meteorite indicate that for an impact of a given velocity, H2O and total volatiles are driven from the sample in the same proportion as present initially. The primitive surface volatile budget of a planet growing by accretion would have the same bulk elemental composition as the volatiles in the incident planetesimals. Incipient devolatilization of Murchison occurs at an initial shock pressure of about 11 GPa and complete devolatilization occurs at a pressure of about 30 GPa. For the earth, incipient and complete devolatilization of accreting planetesimals would occur when the planet reached approximately 12 percent and 27 percent, respectively, of its present-day radius. Impact-induced devolatilization would profoundly affect the volatile distribution within the accreting planet. Prior to metallic core formation and internal differentiation the growing planet would have a very small core with the same volatile content as the incident material, a volatile depleted mantle, and an extremely volatile rich surface. In the case of the earth, 99.4 wt pct of the total incident volatile material would end up on or near the planetary surface.

  8. Shock-induced volatile loss from a carbonaceous chondrite: Implications for planetary accretion

    Science.gov (United States)

    Tyburczy, J. A.; Frisch, B.; Ahrens, T. J.

    1986-01-01

    Solid recovery impact-induced volatile loss experiments on the Murchison C2M meteorite indicate that for an impact of a given velocity, H2O and total volatiles are driven from the sample in the same proportion as present initially. The primitive surface volatile budget of a planet growing by accretion would have the same bulk elemental composition as the volatiles in the incident planetesimals. Incipient devolatilization of Murchison occurs at an initial shock pressure of about 11 GPa and complete devolatilization occurs at a pressure of about 30 GPa. For the Earth, incipient and complete devolatilization of accreting planetesimals would occur when the planet reached approximately 12% and 27%, respectively, of its present-day radius. Impact-induced devolatilization would profoundly affect the volatile distribution within the accreting planet. Prior to metallic core formation and internal differentiation the growing planet would have a very small core with the same volatile content as the incident material, a volatile depleted mantle, and an extremely volatile rich surface. In the case of the Earth, 99.4 wt% of the total incident volatile material would end up on or near the planetary surface.

  9. An analysis of tank and pump pit flammable gas data in support of saltwater pumping safety basis simplification

    Energy Technology Data Exchange (ETDEWEB)

    MCCAIN, D.J.

    2000-07-26

    Hanford Site high-level waste tanks are interim stabilized by pumping supernatant and interstitial waste liquids to double-shell tanks (DSTs) through a saltwell pump (SWP). The motor to this SWP is located atop the tank, inside a pump pit. A pumping line extends down from the pump motor into the well area, located in the salt/sludge solids in the tank below. Pumping of these wastes is complicated by the fact that some of the wastes generate and retain potentially hazardous amounts of hydrogen, nitrous oxide, and ammonia. Monitoring of flammable gas concentrations during saltwell pumping activities has shown that one effect of pumping is acceleration in the release of accumulated hydrogen. A second effect is that of a temporarily increased hydrogen concentration in both the dome space and pump pit. There is a safety concern that the hydrogen concentration during saltwell pumping activities might approach the lower flammability limit (LFL) in either the tank dome space or the pump pit. The current Final Safety Analysis Report (FSAR) (CHG 2000) for saltwell pumping requires continuous flammable gas monitoring in both the pump pit and the tank vapor space during saltwell pumping. The FSAR also requires that portable exhauster fans be available by most of the passively ventilated tanks to be saltwell pumped in the event that additional air flow is required to dilute the headspace concentration of flammable gases to acceptable levels. The first objective of this analysis is to review the need for an auxiliary exhauster. Since the purpose of the exhauster is to diffuse unacceptably high flammable gas concentrations, discovery of an alternate method of accomplishing the same task may provide cost savings. The method reviewed is that of temporarily stopping the saltwell pumps. This analysis also examines the typical hydrogen concentration peaks and the rates of increase in hydrogen levels already witnessed in tanks during saltwell pumping activities. The historical data

  10. Recent Advances in Volatiles of Teas

    Directory of Open Access Journals (Sweden)

    Xin-Qiang Zheng

    2016-03-01

    Full Text Available Volatile compounds are important components of tea aroma, a key attribute of sensory quality. The present review examines the formation of aromatic volatiles of various kinds of teas and factors influencing the formation of tea volatiles, including tea cultivar, growing environment and agronomic practices, processing method and storage of tea. The determination of tea volatiles and the relationship of active-aroma volatiles with the sensory qualities of tea are also discussed in the present paper.

  11. Copper corrosion originated by volatile organic acid vapours; Corrosion del cobre por acidos organicos volatiles

    Energy Technology Data Exchange (ETDEWEB)

    Cano, E.; Polo, J. L.; Kong, D. Y.; Mora, E. M.; Lopez-Caballero, J. A.; Bastidas, J. M.

    2004-07-01

    The corrosion of copper in the presence of volatile organic acids is frequent. Thus, for example, it is known that failures by corrosion of the copper tubes take place in the air conditioning equipment, caused by volatile organic acids emitted by oils used in their manufacturing. Another frequent case is the corrosion of copper objects caused by the acids emitted by the materials used in packing, wood and resins, amongst others. This communication presents the corrosion results of copper exposed to 100% relative humidity and different concentrations (10-300ppm) of formic (HCOOH), acetic (CH{sub 3}COOH), propionic (CH{sub 3}CH{sub 2}COOH) and butyric (CH{sub 3}(CH{sub 2}){sub 2}COOH) acid vapours, for short exposure times. the techniques used were gravimetric analysis, scanning electron microscopy (SEM) and X-ray diffraction (XRD). (Author) 9 refs.

  12. 可燃制冷剂标准修订进展%Progress on the Revision of Safety Standards for Flammable Refrigerants

    Institute of Scientific and Technical Information of China (English)

    吴克安; 郭智恺; 郑冬芳; 谢品赞; 张建君

    2014-01-01

    This paper focused on the revision of safety standards related to the refrigerants and systems’ flammability all over the world. The attitude towards the strongly flammable refrigerant applications such as hydrocarbons was discussed. Result showed that most of the states’ attitudes towards the weaker flammable refrigerants were relaxed, but there were still disagreements for the strongly flammable hydrocarbons.%阐述了全球各主要地区制冷剂及系统关于可燃性的安全标准的修订情况,并介绍了各国对于HCs类易可燃性制冷剂的应用态度。各国对弱可燃制冷剂的态度有所松动,但对于HCs类易燃制冷剂的应用仍有较大分歧。

  13. Nanostructured Polypyrrole-Based Ammonia and Volatile Organic Compound Sensors.

    Science.gov (United States)

    Šetka, Milena; Drbohlavová, Jana; Hubálek, Jaromír

    2017-03-10

    The aim of this review is to summarize the recent progress in the fabrication of efficient nanostructured polymer-based sensors with special focus on polypyrrole. The correlation between physico-chemical parameters, mainly morphology of various polypyrrole nanostructures, and their sensitivity towards selected gas and volatile organic compounds (VOC) is provided. The different approaches of polypyrrole modification with other functional materials are also discussed. With respect to possible sensors application in medicine, namely in the diagnosis of diseases via the detection of volatile biomarkers from human breath, the sensor interaction with humidity is described as well. The major attention is paid to analytes such as ammonia and various alcohols.

  14. Nanostructured Polypyrrole-Based Ammonia and Volatile Organic Compound Sensors

    Directory of Open Access Journals (Sweden)

    Milena Šetka

    2017-03-01

    Full Text Available The aim of this review is to summarize the recent progress in the fabrication of efficient nanostructured polymer-based sensors with special focus on polypyrrole. The correlation between physico-chemical parameters, mainly morphology of various polypyrrole nanostructures, and their sensitivity towards selected gas and volatile organic compounds (VOC is provided. The different approaches of polypyrrole modification with other functional materials are also discussed. With respect to possible sensors application in medicine, namely in the diagnosis of diseases via the detection of volatile biomarkers from human breath, the sensor interaction with humidity is described as well. The major attention is paid to analytes such as ammonia and various alcohols.

  15. Nanostructured Polypyrrole-Based Ammonia and Volatile Organic Compound Sensors

    Science.gov (United States)

    Šetka, Milena; Drbohlavová, Jana; Hubálek, Jaromír

    2017-01-01

    The aim of this review is to summarize the recent progress in the fabrication of efficient nanostructured polymer-based sensors with special focus on polypyrrole. The correlation between physico-chemical parameters, mainly morphology of various polypyrrole nanostructures, and their sensitivity towards selected gas and volatile organic compounds (VOC) is provided. The different approaches of polypyrrole modification with other functional materials are also discussed. With respect to possible sensors application in medicine, namely in the diagnosis of diseases via the detection of volatile biomarkers from human breath, the sensor interaction with humidity is described as well. The major attention is paid to analytes such as ammonia and various alcohols. PMID:28287435

  16. Spiral mining for lunar volatiles

    Science.gov (United States)

    Schmitt, H. H.; Kulcinski, G. L.; Sviatoslavsky, I. N.; Carrier, W. D., III

    Lunar spiral mining, extending outward from a periodically mobile central power and processing station represents an alternative for comparison with more traditional mining schemes. In this concept, a mining machine would separate regolith fines and extract the contained volatiles. Volatiles then would be pumped along the miner's support arm to the central station for refining and for export or storage. The basic architecture of the central processing station would be cylindrical. A central core area could house the power subsystem of hydrogen-oxygen engines or fuel cells. Habitat sections and other crew occupied areas could be arranged around the power generation core. The outer cylinder could include all volatile refining subsystems. Solar thermal power collectors and reflectors would be positioned on top of the central station. Long term exploitation of a volatile resource region would begin with establishment of a support base at the center of a long boundary of the region. The mining tract for each spiral mining system would extend orthogonal to this boundary. New spiral mining systems would be activated along parallel tracts as demand for lunar He-3 and other solar wind volatiles increased.

  17. RICE PRICE VOLATILITY IN EAST JAVA

    Directory of Open Access Journals (Sweden)

    Wati R.Y.E.

    2017-09-01

    Full Text Available The purpose of the research is analyzing the volatility and volatility spillover of monthly price of paddy at the level of farmers and consumers in 2010-2016. ARCH/GARCH used to analyze volatility and GARCH BEKK-model is used to analyze the volatility spillover. The results of the analysis show that price volatility at the farmer level is very high (extremely high volatility, price volatility at the consumer level is low (low volatility, and volatility spillover does not occur between the farmers and the consumers market. The need to guarantee an effective floor price as well as information disclosure related to the market commodity prices so that the pattern of prices transmission among interrelated markets can be symmetrical.

  18. The price of fixed income market volatility

    CERN Document Server

    Mele, Antonio

    2015-01-01

    Fixed income volatility and equity volatility evolve heterogeneously over time, co-moving disproportionately during periods of global imbalances and each reacting to events of different nature. While the methodology for options-based "model-free" pricing of equity volatility has been known for some time, little is known about analogous methodologies for pricing various fixed income volatilities. This book fills this gap and provides a unified evaluation framework of fixed income volatility while dealing with disparate markets such as interest-rate swaps, government bonds, time-deposits and credit. It develops model-free, forward looking indexes of fixed-income volatility that match different quoting conventions across various markets, and uncovers subtle yet important pitfalls arising from naïve superimpositions of the standard equity volatility methodology when pricing various fixed income volatilities. The ultimate goal of the authors´ efforts is to make interest rate volatility standardization a valuable...

  19. A QSPR model for estimation of lower flammability limit temperature of pure compounds based on molecular structure.

    Science.gov (United States)

    Gharagheizi, Farhad

    2009-09-30

    In this study, a quantitative structure-property relationship was presented to estimate lower flammability limit temperature (LFLT) of pure compounds. This relationship is a multi-linear equation and has six parameters. These chemical structure-based parameters were selected from 1664 molecular-based parameters by genetic algorithm multivariate linear regression (GA-MLR). Since 1171 compounds were used to develop this equation, the model can be used to estimate the LFLT of a wide range of pure compounds.

  20. Experimental flammability limits and associated theoretical flame temperatures as a tool for predicting the temperature dependence of these limits

    OpenAIRE

    Zlochower, Isaac A.

    2012-01-01

    The utility and limitations of adiabatic flame temperature calculations and minimum mixture energies in predicting the temperature dependence of flammability limits are explored. The limiting flame temperatures at constant pressure (1 bar) are calculated using a standard widely-used thermodynamic computer program. The computation is based on the calculated limiting flame temperature value at the reference initial temperature and the experimental limit concentration. The values recently determ...

  1. Flammability of Cellulose-Based Fibers and the Effect of Structure of Phosphorus Compounds on Their Flame Retardancy

    OpenAIRE

    Khalifah A. Salmeia; Milijana Jovic; Audrone Ragaisiene; Zaneta Rukuiziene; Rimvydas Milasius; Daiva Mikucioniene; Sabyasachi Gaan

    2016-01-01

    Cellulose fibers are promoted for use in various textile applications due their sustainable nature. Cellulose-based fibers vary considerably in their mechanical and flammability properties depending on their chemical composition. The chemical composition of a cellulose-based fiber is further dependent on their source (i.e., seed, leaf, cane, fruit, wood, bast, and grass). Being organic in nature, cellulose fibers, and their products thereof, pose considerable fire risk. In this work we have c...

  2. Investigation of the Extinguishing Features for Liquid Fuels and Organic Flammable Liquids Atomized by a Water Flow

    OpenAIRE

    2016-01-01

    The processes of heat and mass transfer were investigated experimentally while moving and evaporating the atomized water flow in high-temperature combustion products of typical liquid fuels and organic flammable liquids: gasoline, kerosene, acetone, crude oil, industrial alcohol. We determined typical periods of liquid extinguishing by an atomized water flow of various dispersability. Data of the discharge of extinguishing medium corresponding to various parameters of atomization and duration...

  3. Volatile Release and Ignition Behaviors of Single Coal Particles at Different Oxygen Concentrations Under Microgravity

    Science.gov (United States)

    Liu, Bing; Zhang, Zhezi; Zhang, Hai; Zhang, Dongke

    2016-05-01

    An experimental study on ignition and combustion of single coal particles under different O 2 concentrations was conducted at both normal (1-g) and microgravity ( μ-g) in the first time. The surface and centre temperatures of the bituminous coal particle with initial diameter of ˜ 2.0mm were measured by the monochromatic imaging technique using a short wavelength infrared (SWIR) camera and an embedded fine thermocouple respectively. Results revealed that at μ-g, ignition of the tested coal particles was homogeneous. O 2 concentration significantly affects the shape, ignition temperature and ignition delay time of the volatile flames. A mathematical model considering thermal conduction inside the coal particle was developed to describe the ignition process of single particle, adopting the volatile matter flammability limit as the homogeneous ignition criterion. The predicted ignition temperatures were slightly lower but closer to μ-g data. And the predicted variation trends of ignition temperature and delay time under different O 2 concentrations agreed well with the μ-g experimental results.

  4. Emissions of volatile organic compounds from heated needles and twigs of Pinus pumila

    Institute of Scientific and Technical Information of China (English)

    ZHAO Feng-jun; SHU Li-fu; WANG Qiu-hua; WANG Ming-yu; TIAN Xiao-rui

    2011-01-01

    A study was conducted to explore the mechanism that emissions of volatile organic compounds (VOC) from heated needles and twigs (200℃, within 15 min) of Pinus purnila affect fire behaviours using the technology of Thermal Desorption - Gas Chromatography-Mass Spectrometry (TD-GC-MS). The results indicated that the main components of VOC from heated needles and twigs are terpenoids. Most of these terpenoids are monoterpenes. Terpenoids account for 72.93% for the needles and 92.40% for the twigs of the total VOC, and their emis sion ratios are 61.200 μg·g-1 and 217.060 μtg·g-1 respectively. Heated twigs can emit more terpenoids than heated needles because twigs had more volatile oils than needles. In actual fires, these large amounts of terpenoid emissions, especially the monoterpene emissions, have strong effects on fire behaviors that are not only in the initial stage but also in the fast propagation stage of fires. These flammable gases are capable of causing violent combustion and creating crown fires. In addition, if these gases accumulate in an uneven geographical area, there will be a possible for eruptive fires and/or fires fiashover to occur.

  5. Numerical modeling and experimental analysis of volatile contaminant removal from vertical flow filters

    NARCIS (Netherlands)

    De Biase, C.

    2012-01-01

    Vertical flow filters (unplanted) and vertical flow constructed wetlands (planted), simple and inexpensive technologies to treat effectively volatile organic compounds (VOCs) contaminated water, consist of containers filled with granular material which is intermittently fed with contaminated water.

  6. Estimating the gas permeability of commercial volatile corrosion inhibitors at elevated temperatures with thermo-gravimetry

    CSIR Research Space (South Africa)

    Pieterse, N

    2006-08-01

    Full Text Available permeability of commercial volatile corrosion inhibitors at elevated temperatures with thermo-gravimetry Niel Pieterse a, Walter W. Focke a,*, Eino Vuorinen b, Ilona Racz c a Department of Chemical Engineering, Institute of Applied Materials, University...

  7. Effect of Zirconium Dioxide Nanoparticles as a Mordant on Properties of Wool with Thyme: Dyeing, Flammability and Antibacterial

    Directory of Open Access Journals (Sweden)

    M. Taheri

    2015-03-01

    Full Text Available In this research, the zirconium dioxide nanoparticle was synthesized and the effect of these particles as a mordant on properties of wool fabric in dying process with a natural dye,also flammability and antibacterial properties were studied. The wool fabrics were treated with different concentrations of zirconium dioxide nanoparticles including 1, 3, 6 and 9% o.w.f. and the dyeing process was carried out on the fabrics in the states before, simultaneously and after mordanting with Thyme. The chemical characteristics and the changes induced by zirconium were investigated by Fourier-transform infrared spectra (FTIR.The influence of the amount of nano-ZrO2 and the type of mordanting treatment on dye absorbency were studied by reflectance spectrophotometer (RS. Flammability of samples was investigated by horizontal flammability test (HFT.The antibacterial properties were determined by reduction growth of a Gram-negative bacterium E. coli and a Gram-positive bacterium Staphylococcus aureus. The surfaces of untreated and treated fabrics were evaluated by scanning electron microscopy to observe the morphological changes.

  8. Development of a cost efficient methodology to perform allocation of flammable and toxic gas detectors applying CFD tools

    Energy Technology Data Exchange (ETDEWEB)

    Storch, Rafael Brod; Rocha, Gean Felipe Almeida [Det Norske Veritas (DNV), Rio de Janeiro, RJ (Brazil); Nalvarte, Gladys Augusta Zevallos [Det Norske Veritas (DNV), Novik (Norway)

    2012-07-01

    This paper is aimed to present a computational procedure for flammable and toxic gas detector allocation and quantification developed by DNV. The proposed methodology applies Computational Fluid Dynamics (CFD) simulations as well as operational and safety characteristics of the analyzed region to assess the optimal number of toxic and flammable gas detectors and their optimal location. A probabilistic approach is also used when applying the DNV software ThorEXPRESSLite, following NORSOK Z013 Annex G and presented in HUSER et al. 2000 and HUSER et al. 2001, when the flammable gas detectors are assessed. A DNV developed program, DetLoc, is used to run in an iterative way the procedure described above leading to an automatic calculation of the gas detectors location and number. The main advantage of the methodology presented above is the independence of human interaction in the gas detector allocation leading to a more precise and free of human judgment allocation. Thus, a reproducible allocation is generated when comparing several different analyses and a global criteria appliance is guaranteed through different regions in the same project. A case study is presented applying the proposed methodology. (author)

  9. Observability of market daily volatility

    Science.gov (United States)

    Petroni, Filippo; Serva, Maurizio

    2016-02-01

    We study the price dynamics of 65 stocks from the Dow Jones Composite Average from 1973 to 2014. We show that it is possible to define a Daily Market Volatility σ(t) which is directly observable from data. This quantity is usually indirectly defined by r(t) = σ(t) ω(t) where the r(t) are the daily returns of the market index and the ω(t) are i.i.d. random variables with vanishing average and unitary variance. The relation r(t) = σ(t) ω(t) alone is unable to give an operative definition of the index volatility, which remains unobservable. On the contrary, we show that using the whole information available in the market, the index volatility can be operatively defined and detected.

  10. Consistent ranking of volatility models

    DEFF Research Database (Denmark)

    Hansen, Peter Reinhard; Lunde, Asger

    2006-01-01

    result in an inferior model being chosen as "best" with a probability that converges to one as the sample size increases. We document the practical relevance of this problem in an empirical application and by simulation experiments. Our results provide an additional argument for using the realized...... variance in out-of-sample evaluations rather than the squared return. We derive the theoretical results in a general framework that is not specific to the comparison of volatility models. Similar problems can arise in comparisons of forecasting models whenever the predicted variable is a latent variable.......We show that the empirical ranking of volatility models can be inconsistent for the true ranking if the evaluation is based on a proxy for the population measure of volatility. For example, the substitution of a squared return for the conditional variance in the evaluation of ARCH-type models can...

  11. Oil Volatility Risk and Expected Stock Returns

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Pan, Xuhui (Nick)

    After the financialization of commodity futures markets in 2004-05 oil volatility has become a strong predictor of returns and volatility of the overall stock market. Furthermore, stocks' exposure to oil volatility risk now drives the cross-section of expected returns. The difference in average...... return between the quintile of stocks with low exposure and high exposure to oil volatility is significant at 0.66% per month, and oil volatility risk carries a significant risk premium of -0.60% per month. In the post-financialization period, oil volatility risk is strongly related with various measures...

  12. Rhenium volatilization in waste glasses

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Kai; Pierce, David A. [Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Hrma, Pavel, E-mail: pavel.hrma@pnnl.gov [Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Schweiger, Michael J. [Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Kruger, Albert A. [U.S. Department of Energy, Office of River Protection, Richland, WA 99352 (United States)

    2015-09-15

    Highlights: • Re did not volatilize from a HLW feed until 1000 °C. • Re began to volatilize from LAW feeds at ∼600 °C. • The vigorous foaming and generation of gases from salts enhanced Re evaporation in LAW feeds. • The HLW glass with less foaming and salts is a promising medium for Tc immobilization. - Abstract: We investigated volatilization of rhenium (Re), sulfur, cesium, and iodine during the course of conversion of high-level waste melter feed to glass and compared the results for Re volatilization with those in low-activity waste borosilicate glasses. Whereas Re did not volatilize from high-level waste feed heated at 5 K min{sup −1} until 1000 °C, it began to volatilize from low-activity waste borosilicate glass feeds at ∼600 °C, a temperature ∼200 °C below the onset temperature of evaporation from pure KReO{sub 4}. Below 800 °C, perrhenate evaporation in low-activity waste melter feeds was enhanced by vigorous foaming and generation of gases from molten salts as they reacted with the glass-forming constituents. At high temperatures, when the glass-forming phase was consolidated, perrhenates were transported to the top surface of glass melt in bubbles, typically together with sulfates and halides. Based on the results of this study (to be considered preliminary at this stage), the high-level waste glass with less foaming and salts appears a promising medium for technetium immobilization.

  13. DOES ENERGY CONSUMPTION VOLATILITY AFFECT REAL GDP VOLATILITY? AN EMPIRICAL ANALYSIS FOR THE UK

    Directory of Open Access Journals (Sweden)

    Abdul Rashid

    2013-10-01

    Full Text Available This paper empirically examines the relation between energy consumption volatility and unpredictable variations in real gross domestic product (GDP in the UK. Estimating the Markov switching ARCH model we find a significant regime switching in the behavior of both energy consumption and GDP volatility. The results from the Markov regime-switching model show that the variability of energy consumption has a significant role to play in determining the behavior of GDP volatilities. Moreover, the results suggest that the impacts of unpredictable variations in energy consumption on GDP volatility are asymmetric, depending on the intensity of volatility. In particular, we find that while there is no significant contemporaneous relationship between energy consumption volatility and GDP volatility in the first (low-volatility regime, GDP volatility is significantly positively related to the volatility of energy utilization in the second (high-volatility regime.

  14. Bio-based structural composite materials for aerospace applications

    CSIR Research Space (South Africa)

    Jacob John, Maya

    2008-09-01

    Full Text Available honeycomb cores were supplied by AIRBUS. 4. RESULTS AND DISCUSSION 4.1 Flame retardant treatment The most important regulation in aerospace applications is maintaining the fire, smoke and toxicity (FST) standards. Flax is a flammable material... compounds, generally have low toxicity, have been shown to be effective flame retardants and smoke suppressants for natural fibres and synthetic polymers4 and phosphates have long been used for flame retarding cellulosic materials2 In this study, a...

  15. The influence of leaf morphology on litter flammability and its utility for interpreting palaeofire.

    Science.gov (United States)

    Belcher, Claire M

    2016-06-05

    Studies of palaeofire rely on quantifying the abundance of fossil charcoals in sediments to estimate changes in fire activity. However, gaining an understanding of the behaviour of palaeofires is also essential if we are to determine the palaeoecological impact of wildfires. Here, I use experimental approaches to explore relationships between litter fire behaviour and leaf traits that are observable in the fossil record. Fire calorimetry was used to assess the flammability of 15 species of conifer litter and indicated that leaf morphology related to litter bulk density and fuel load that determined the duration of burning and the total energy released. These data were applied to a fossil case study that couples estimates of palaeolitter fire behaviour to charcoal-based estimates of fire activity and observations of palaeoecological changes. The case study reveals that significant changes in fire activity and behaviour likely fed back to determine ecosystem composition. This work highlights that we can recognize and measure plant traits in the fossil record that relate to fire behaviour and therefore that further research is warranted towards estimating palaeofire behaviour as it can enhance our ability to interpret the palaeoecological impact of palaeofires throughout Earth's long evolutionary history.This article is part of the themed issue 'The interaction of fire and mankind'.

  16. THERMAL DECOMPOSITION AND FLAMMABILITY OF ACRYLONITRILE-BUTADIENE-STYRENE/MULTI-WALLED CARBON NANOTUBES COMPOSITES

    Institute of Scientific and Technical Information of China (English)

    Li-fang Tong; Hai-yun Ma; Zheng-ping Fang

    2008-01-01

    Thermal and flammability properties of acrylonitrile-butadiene-styrene copolymer (ABS) with the addition of multi-walled carbon nanotubes (MWNTs) were studied. ABS/MWNTs composites were prepared via melt blending with the MWNTs content varied from 0.2% to 4.0% by mass. Thermogravimetry results showed that the addition of MWNTs accelerated the degradation of ABS during the whole process under air atmosphere, and both onset and maximum degradation temperature were lower than those of pure ABS. The destabilization effect of MWNTs on the thermal stability of the composites became unobvious under nitrogen, and the addition of MWNTs could improve the maximum degradation temperature. The heat release rate and time of ignition (tign) for the composites reduced greatly with the addition of MWNTs especially when the concentration of nanotubes was higher than 1.0%. The accumulation of carbon nanotubes with a network structure was observed and the char layer became thicker with increasing nanotubes concentration. Results from Raman spectra showed a higher degree of graphitization for the residues of ABS/MWNTs composites.

  17. The deforestation story: testing for anthropogenic origins of Africa's flammable grassy biomes.

    Science.gov (United States)

    Bond, William; Zaloumis, Nicholas P

    2016-06-05

    Africa has the most extensive C4 grassy biomes of any continent. They are highly flammable accounting for greater than 70% of the world's burnt area. Much of Africa's savannas and grasslands occur in climates warm enough and wet enough to support closed forests. The combination of open grassy systems and the frequent fires they support have long been interpreted as anthropogenic artefacts caused by humans igniting frequent fires. True grasslands, it was believed, would be restricted to climates too dry or too cold to support closed woody vegetation. The idea that higher-rainfall savannas are anthropogenic and that fires are of human origin has led to initiatives to 'reforest' Africa's open grassy systems paid for by carbon credits under the assumption that the net effect of converting these system to forests would sequester carbon, reduce greenhouse gases and mitigate global warming. This paper reviews evidence for the antiquity of African grassy ecosystems and for the fires that they sustain. Africa's grassy biomes and the fires that maintain them are ancient and there is no support for the idea that humans caused large-scale deforestation. Indicators of old-growth grasslands are described. These can help distinguish secondary grasslands suitable for reforestation from ancient grasslands that should not be afforested.This article is part of the themed issue 'The interaction of fire and mankind'.

  18. Position for determining gas-phase volatile organic compound concentrations in transuranic waste containers. Revision 2

    Energy Technology Data Exchange (ETDEWEB)

    Connolly, M.J.; Liekhus, K.J. [Lockheed Martin Idaho Technologies Co., Idaho Falls, ID (United States). Idaho National Engineering and Environmental Lab.; Djordjevic, S.M.; Loehr, C.A.; Spangler, L.R. [Benchmark Environmental Corp. (United States)

    1998-06-01

    In the conditional no-migration determination (NMD) for the test phase of the Waste Isolation Pilot Plant (WIPP), the US Environmental Protection Agency (EPA) imposed certain conditions on the US Department of Energy (DOE) regarding gas phase volatile organic compound (VOC) concentrations in the void space of transuranic (TRU) waste containers. Specifically, the EPA required the DOE to ensure that each waste container has no layer of confinement that contains flammable mixtures of gases or mixtures of gases that could become flammable when mixed with air. The EPA also required that sampling of the headspace of waste containers outside inner layers of confinement be representative of the entire void space of the container. The EPA stated that all layers of confinement in a container would have to be sampled until DOE can demonstrate to the EPA that sampling of all layers is either unnecessary or can be safely reduced. A test program was conducted at the Idaho National Engineering and Environmental Laboratory (INEEL) to demonstrate that the gas phase VOC concentration in the void space of each layer of confinement in vented drums can be estimated from measured drum headspace using a theoretical transport model and that sampling of each layer of confinement is unnecessary. This report summarizes the studies performed in the INEEL test program and extends them for the purpose of developing a methodology for determining gas phase VOC concentrations in both vented and unvented TRU waste containers. The methodology specifies conditions under which waste drum headspace gases can be said to be representative of drum gases as a whole and describes a method for predicting drum concentrations in situations where the headspace concentration is not representative. The methodology addresses the approach for determining the drum VOC gas content for two purposes: operational period drum handling and operational period no-migration calculations.

  19. Factors affecting the volatilization of volatile organic compounds from wastewater

    Directory of Open Access Journals (Sweden)

    Junya Intamanee

    2006-09-01

    Full Text Available This study aimed to understand the influence of the wind speed (U10cm, water depth (h and suspended solids (SS on mass transfer coefficient (KOLa of volatile organic compounds (VOCs volatilized from wastewater. The novelty of this work is not the method used to determine KOLa but rather the use of actual wastewater instead of pure water as previously reported. The influence of U10cm, h, and SS on KOLa was performed using a volatilization tank with the volume of 100-350 L. Methyl Ethyl Ketone (MEK was selected as a representative of VOCs investigated here in. The results revealed that the relationship between KOLa and the wind speeds falls into two regimes with a break at the wind speed of 2.4 m/s. At U10cm 2.4 m/s, KOLa increased more rapidly. The relationship between KOLa and U10cm was also linear but has a distinctly higher slope. For the KOLa dependency on water depth, the KOLa decreased significantly with increasing water depth up to a certain water depth after that the increase in water depth had small effect on KOLa. The suspended solids in wastewater also played an important role on KOLa. Increased SS resulted in a significant reduction of KOLa over the investigated range of SS. Finally, the comparison between KOLa obtained from wastewater and that of pure water revealed that KOLa from wastewater were much lower than that of pure water which was pronounced at high wind speed and at small water depth. This was due the presence of organic mass in wastewater which provided a barrier to mass transfer and reduced the degree of turbulence in the water body resulting in low volatilization rate and thus KOLa. From these results, the mass transfer model for predicting VOCs emission from wastewater should be developed based on the volatilization of VOCs from wastewater rather than that from pure water.

  20. Characterization of the explosion risk in processes involving flammable gases, vapors or dusts; Caracterisation du risque d'explosion dans les procedes mettant en oeuvre des gaz, vapeurs ou poussieres inflammables

    Energy Technology Data Exchange (ETDEWEB)

    Chaineaux, J. [Institut National de l' Environnement Industriel et des Risques, 60 - Verneuil en Halatte (INERIS) (France)

    2001-07-01

    The knowledge of the main flammability, explodability and oxidizability characteristics of flammable gases, vapors and dusts is a necessary prerequisite to the definition of prevention and protection means against explosions. After a recall about the combustion reaction, each characteristic is defined and its link with the physics of combustion starting and propagation is indicated. For some characteristics, the different orders of scale is also indicated in the case of flammable gases, vapors and dusts. (J.S.)

  1. Novel Set-Up for Low-Disturbance Sampling of Volatile and Non-volatile Compounds from Plant Roots.

    Science.gov (United States)

    Eilers, Elisabeth J; Pauls, Gerhard; Rillig, Matthias C; Hansson, Bill S; Hilker, Monika; Reinecke, Andreas

    2015-03-01

    Most studies on rhizosphere chemicals are carried out in substrate-free set-ups or in artificial substrates using sampling methods that require an air flow and may thus cause disturbance to the rhizosphere. Our study aimed to develop a simplified and inexpensive system that allows analysis of rhizosphere chemicals at experimentally less disturbed conditions. We designed a mesocosm in which volatile rhizosphere chemicals were sampled passively (by diffusion) without air- and water flow on polydimethylsiloxane-(PDMS) tubes. Dandelion (Taraxacum sect. ruderalia) was used as model plant; roots were left undamaged. Fifteen volatiles were retrieved from the sorptive material by thermal desorption for analysis by gas chromatography/mass spectrometry (GC/MS). Furthermore, three sugars were collected from the rhizosphere substrate by aqueous extraction and derivatized prior to GC/MS analysis. In order to study how the quantity of detected rhizosphere compounds depends on the type of soil or substrate, we determined the matrix-dependent recovery of synthetic rhizosphere chemicals. Furthermore, we compared sorption of volatiles on PDMS tubes with and without direct contact to the substrate. The results show that the newly designed mesocosm is suitable for low-invasive extraction of volatile and non-volatile compounds from rhizospheres. We further highlight how strongly the type of substrate and contact of PDMS tubes to the substrate affect the detectability of compounds from rhizospheres.

  2. Quantitative estimates of the volatility of ambient organic aerosol

    Directory of Open Access Journals (Sweden)

    C. D. Cappa

    2010-01-01

    Full Text Available Measurements of the sensitivity of organic aerosol (OA, and its components mass to changes in temperature were recently reported by Huffman et al. (2009 using a tandem thermodenuder-aerosol mass spectrometer (TD-AMS system in Mexico City and the Los Angeles area. Here, we use these measurements to derive quantitative estimates of aerosol volatility within the framework of absorptive partitioning theory using a kinetic model of aerosol evaporation in the TD. OA volatility distributions (or "basis-sets" are determined using several assumptions as to the enthalpy of vaporization (ΔHvap. We present two definitions of "non-volatile OA," one being a global and one a local definition. Based on these definitions, our analysis indicates that a substantial fraction of the organic aerosol is comprised of non-volatile components that will not evaporate under any atmospheric conditions, on the order of 50–80% when the most realistic ΔHvap assumptions are considered. The sensitivity of the total OA mass to dilution and ambient changes in temperature has been assessed for the various ΔHvap assumptions. The temperature sensitivity is relatively independent of the particular ΔHvap assumptions whereas dilution sensitivity is found to be greatest for the low (ΔHvap = 50 kJ/mol and lowest for the high (ΔHvap = 150 kJ/mol assumptions. This difference arises from the high ΔHvap assumptions yielding volatility distributions with a greater fraction of non-volatile material than the low ΔHvap assumptions. If the observations are fit using a 1 or 2-component model the sensitivity of the OA to dilution is unrealistically high. An empirical method introduced by Faulhaber et al. (2009 has also been used to independently estimate a volatility distribution for the ambient OA and is found to give results consistent with the high and variable ΔHvap assumptions. Our

  3. Flammability limits of lithium-ion battery thermal runaway vent gas in air and the inerting effects of halon 1301

    Science.gov (United States)

    Karp, Matthew Eugene

    Lithium-ion (rechargeable) and lithium-metal (non-rechargeable) battery cells put aircraft at risk of igniting and fueling fires. Lithium batteries can be packed in bulk and shipped in the cargo holds of freighter aircraft; currently lithium batteries are banned from bulk shipment on passenger aircraft [1]. The federally regulated Class C cargo compartment extinguishing system's utilization of a 5 %vol Halon 1301 knockdown concentration and a sustained 3 %vol Halon 1301 may not be sufficient at inerting lithium-ion battery vent gas and air mixtures [2]. At 5 %vol Halon 1301 the flammability limits of lithium-ion premixed battery vent gas (Li-Ion pBVG) in air range from 13.80 %vol to 26.07 %vol Li-Ion pBVG. Testing suggests that 8.59 %vol Halon 1301 is required to render all ratios of the Li-Ion pBVG in air inert. The lower flammability limit (LFL) and upper flammability limit (UFL) of hydrogen and air mixtures are 4.95 %vol and 76.52 %vol hydrogen, respectively. With the addition of 10 %vol and 20 %vol Halon 1301 the LFL is 9.02 %vol and 11.55 %vol hydrogen, respectively, and the UFL is 45.70 %vol and 28.39 %vol hydrogen, respectively. The minimum inerting concentration (MIC) of Halon 1301 in hydrogen and air mixtures is 26.72 %vol Halon 1301 at 16.2 %vol hydrogen. The LFL and UFL of Li-Ion pBVG and air mixtures are 7.88 %vol and 37.14 %vol Li-Ion pBVG, respectively. With the addition of 5 %vol, 7 %vol, and 8 %vol Halon 1301 the LFL is 13.80 %vol, 16.15 %vol, and 17.62 % vol Li-Ion pBVG, respectively, and the UFL is 26.07 %vol, 23.31 %vol, and 21.84 %vol Li- Ion pBVG, respectively. The MIC of Halon 1301 in Li-Ion pBVG and air mixtures is 8.59 %vol Halon 1301 at 19.52 %vol Li-Ion pBVG. Le Chatelier's mixing rule has been shown to be an effective measure for estimating the flammability limits of Li-Ion pBVGes. The LFL has a 1.79 % difference while the UFL has a 4.53 % difference. The state of charge (SOC) affects the flammability limits in an apparent parabolic

  4. Modeling the Volatility in Global Fertilizer Prices

    NARCIS (Netherlands)

    P-Y. Chen (Ping-Yu); C-L. Chang (Chia-Lin); C-C. Chen (Chi-Chung); M.J. McAleer (Michael)

    2010-01-01

    textabstractThe main purpose of this paper is to estimate the volatility in global fertilizer prices. The endogenous structural breakpoint unit root test and alternative volatility models, including the generalized autoregressive conditional heteroskedasticity (GARCH) model, Exponential GARCH (EGARC

  5. Fluctuation behaviors of financial return volatility duration

    Science.gov (United States)

    Niu, Hongli; Wang, Jun; Lu, Yunfan

    2016-04-01

    It is of significantly crucial to understand the return volatility of financial markets because it helps to quantify the investment risk, optimize the portfolio, and provide a key input of option pricing models. The characteristics of isolated high volatility events above certain threshold in price fluctuations and the distributions of return intervals between these events arouse great interest in financial research. In the present work, we introduce a new concept of daily return volatility duration, which is defined as the shortest passage time when the future volatility intensity is above or below the current volatility intensity (without predefining a threshold). The statistical properties of the daily return volatility durations for seven representative stock indices from the world financial markets are investigated. Some useful and interesting empirical results of these volatility duration series about the probability distributions, memory effects and multifractal properties are obtained. These results also show that the proposed stock volatility series analysis is a meaningful and beneficial trial.

  6. A Fractionally Integrated Wishart Stochastic Volatility Model

    NARCIS (Netherlands)

    M. Asai (Manabu); M.J. McAleer (Michael)

    2013-01-01

    textabstractThere has recently been growing interest in modeling and estimating alternative continuous time multivariate stochastic volatility models. We propose a continuous time fractionally integrated Wishart stochastic volatility (FIWSV) process. We derive the conditional Laplace transform of

  7. Stochastic Volatility and DSGE Models

    DEFF Research Database (Denmark)

    Andreasen, Martin Møller

    This paper argues that a specification of stochastic volatility commonly used to analyze the Great Moderation in DSGE models may not be appropriate, because the level of a process with this specification does not have conditional or unconditional moments. This is unfortunate because agents may...

  8. Business Cycles, Financial Crises, and Stock Volatility

    OpenAIRE

    G. William Schwert

    1989-01-01

    This paper shows that stock volatility increases during recessions and financial crises from 1834-1987. The evidence reinforces the notion that stock prices are an important business cycle indicator. Using two different statistical models for stock volatility, I show that volatility increases after major financial crises. Moreover. stock volatility decreases and stock prices rise before the Fed increases margin requirements. Thus, there is little reason to believe that public policies can con...

  9. Decomposing European bond and equity volatility

    DEFF Research Database (Denmark)

    Christiansen, Charlotte

    The paper investigates volatility spillover from US and aggregate European asset markets into European national asset markets. A main contribution is that bond and equity volatilities are analyzed simultaneously. A new model belonging to the "volatilityspillover" family is suggested: The conditio...... (stock) volatilities are mainly influenced by bond (stock) effects. Global, regional, and local volatility effects are all important. The introduction of the euro is associated with a structural break....

  10. The january effect across volatility regimes

    OpenAIRE

    Agnani, Betty; Aray, Henry

    2007-01-01

    Using a Markov regime switching model, this article presents evidence on the well-known January effect on stock returns. The specification allows a distinction to be drawn between two regimes, one with high volatility and other with low volatility. We obtain a time-varying January effect that is, in general, positive and significant in both volatility regimes. However, this effect is larger in the high volatility regime. In sharp contrast with most previous literature we find two major result...

  11. Exponential Smoothing, Long Memory and Volatility Prediction

    DEFF Research Database (Denmark)

    Proietti, Tommaso

    Extracting and forecasting the volatility of financial markets is an important empirical problem. The paper provides a time series characterization of the volatility components arising when the volatility process is fractionally integrated, and proposes a new predictor that can be seen as extensi...... methods for forecasting realized volatility, and that the estimated model confidence sets include the newly proposed fractional lag predictor in all occurrences....

  12. Possible Sources of Polar Volatiles

    Science.gov (United States)

    Schultz, P. H.

    2011-12-01

    Extensive analyses of returned Apollo samples demonstrated that the Moon is extremely volatile poor. While this conclusion remains true, various measurements since the late 90's implicated the presence of water: e.g., enhanced reflection of circularly polarized radar signals and suppression of epithermal neutrons near the poles. More recently, traces of H2O have been discovered inside volcanic glass, along with more significant amounts residing in hydrous minerals (apatite) returned from both highland and mare landing sites. Three recent lunar missions (DIXI, M3, Cassini) identified hydrous phases on/near the lunar surface, whereas the LCROSS probe detected significant quantities of volatiles (OH, H2O and other volatiles) excavated by the Centaur impact. These new mission results and sample studies, however, now allow testing different hypotheses for the generation, trapping, and replenishment of these volatiles. Solar-proton implantation must contribute to the hydrous phases in the lunar regolith in order to account for the observed time-varying abundances and occurrence near the lunar equator. This also cannot be the entire story. The relatively low speed LCROSS-Centaur impact (2.5km/s) could not vaporize such hydrous minerals, yet emissions lines of OH (from the thermal disassociation of H2O), along with other compounds (CO2, NH2) were detected within the first second, before ejecta could reach sunlight. Telescopic observations by Potter and Morgan (1985) discovered a tenuous lunar atmosphere of Na, but the LCROSS UV/Vis spectrometer did not detect the Na-D line until after the ejecta reached sunlight (along with a line pair attributed to Ag). With time, other volatile species emerged (OH, CO). The LAMP instrument on the Lunar Reconnaissance Orbiter had a different viewpoint from the side (rather than from above) and detected many other atomic species release by the LCROSS-Centaur impact. Consequently, it appears that there is a stratigraphy for trapped species

  13. Volatility of organic aerosol and its components in the megacity of Paris

    Science.gov (United States)

    Paciga, Andrea; Karnezi, Eleni; Kostenidou, Evangelia; Hildebrandt, Lea; Psichoudaki, Magda; Engelhart, Gabriella J.; Lee, Byong-Hyoek; Crippa, Monica; Prévôt, André S. H.; Baltensperger, Urs; Pandis, Spyros N.

    2016-02-01

    Using a mass transfer model and the volatility basis set, we estimate the volatility distribution for the organic aerosol (OA) components during summer and winter in Paris, France as part of the collaborative project MEGAPOLI. The concentrations of the OA components as a function of temperature were measured combining data from a thermodenuder and an aerosol mass spectrometer (AMS) with Positive Matrix Factorization (PMF) analysis. The hydrocarbon-like organic aerosol (HOA) had similar volatility distributions for the summer and winter campaigns with half of the material in the saturation concentration bin of 10 µg m-3 and another 35-40 % consisting of low and extremely low volatility organic compounds (LVOCs with effective saturation concentrations C* of 10-3-0.1 µg m-3 and ELVOCs C* less or equal than 10-4 µg m-3, respectively). The winter cooking OA (COA) was more than an order of magnitude less volatile than the summer COA. The low-volatility oxygenated OA (LV-OOA) factor detected in the summer had the lowest volatility of all the derived factors and consisted almost exclusively of ELVOCs. The volatility for the semi-volatile oxygenated OA (SV-OOA) was significantly higher than that of the LV-OOA, containing both semi-volatile organic components (SVOCs with C* in the 1-100 µg m-3 range) and LVOCs. The oxygenated OA (OOA) factor in winter consisted of SVOCs (45 %), LVOCs (25 %) and ELVOCs (30 %). The volatility of marine OA (MOA) was higher than that of the other factors containing around 60 % SVOCs. The biomass burning OA (BBOA) factor contained components with a wide range of volatilities with significant contributions from both SVOCs (50 %) and LVOCs (30 %). Finally, combining the bulk average O : C ratios and volatility distributions of the various factors, our results are placed into the two-dimensional volatility basis set (2D-VBS) framework. The OA factors cover a broad spectrum of volatilities with no direct link between the average volatility and

  14. Oil Volatility Risk and Expected Stock Returns

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Pan, Xuhui (Nick)

    After the financialization of commodity futures markets in 2004-05 oil volatility has become a strong predictor of returns and volatility of the overall stock market. Furthermore, stocks' exposure to oil volatility risk now drives the cross-section of expected returns. The difference in average r...

  15. Volatiles in inter-specific bacterial interactions

    NARCIS (Netherlands)

    Tyc, O.; Zweers, H.; De Boer, W.; Garbeva, P.V.

    2015-01-01

    The importance of volatile organic compounds for functioning of microbes is receiving increased research attention. However, to date very little is known on how inter-specific bacterial interactions effect volatiles production as most studies have been focused on volatiles produced by monocultures o

  16. Volatiles in inter-specific bacterial interactions

    NARCIS (Netherlands)

    Tyc, O.; Zweers, H.; De Boer, W.; Garbeva, P.V.

    2015-01-01

    The importance of volatile organic compounds for functioning of microbes is receiving increased research attention. However, to date very little is known on how inter-specific bacterial interactions effect volatiles production as most studies have been focused on volatiles produced by monocultures

  17. Ammonia volatilization from intensively managed dairy pastures.

    NARCIS (Netherlands)

    Bussink, D.W.

    1996-01-01

    The objectives of this thesis are (i) to quantify NH 3 volatilization from grassland, (ii) to gain understanding of the NH3 volatilization processes on grassland and (iii) to study measures how to reduce NH 3 volatilization from gra

  18. Oil Volatility Risk and Expected Stock Returns

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Pan, Xuhui (Nick)

    After the financialization of commodity futures markets in 2004-05 oil volatility has become a strong predictor of returns and volatility of the overall stock market. Furthermore, stocks' exposure to oil volatility risk now drives the cross-section of expected returns. The difference in average r...

  19. Cost Linkages Transmit Volatility Across Markets

    DEFF Research Database (Denmark)

    Nguyen, Daniel Xuyen; Schaur, Georg

    to link the domestic and export supply costs. This theoretical contribution has two new implications for the exporting firm. First, the demand volatility in the foreign market now directly affects the firm's domestic sales volatility. Second, firms hedge domestic demand volatility with exports. The model...

  20. Quantifying the volatility of organic aerosol in the southeastern US

    Science.gov (United States)

    Saha, Provat K.; Khlystov, Andrey; Yahya, Khairunnisa; Zhang, Yang; Xu, Lu; Ng, Nga L.; Grieshop, Andrew P.

    2017-01-01

    timescales for atmospheric OA are on the order of several minutes to an hour under atmospheric conditions. The OA volatility distributions resulting from fits were compared to those simulated in the Weather, Research and Forecasting model with Chemistry (WRF/Chem) with a current treatment of secondary organic aerosol (SOA) formation. The substantial fraction of low-volatility material observed in our measurements is largely missing from simulations, and OA mass concentrations are underestimated. The large discrepancies between simulations and observations indicate a need to treat low-volatility OA in atmospheric models. Volatility parameters extracted from ambient measurements enable evaluation of emerging treatments for OA (e.g., secondary OA using the volatility basis set or formed via aqueous chemistry) in atmospheric models.

  1. Mantle Volatiles - Distribution and Consequences

    Science.gov (United States)

    Luth, R. W.

    2003-12-01

    Volatiles in the mantle have, for many years, been the subject of intensive study from a number of perspectives. They are of interest because of their potential effects on melting relationships, on transport of major and trace elements, and on the rheological and other physical properties of the mantle. By convention, "volatiles" in this context are constituents that are liquid or gaseous at normal Earth surface conditions. This review will look at the behavior of C-O-H-S-halogen volatiles, beginning with H2O and C-O volatiles.There have been tremendous strides made recently towards understanding how volatiles in general and water in particular is transported and stored in the mantle. This progress is based on research on a number of fronts: studies of mantle-derived samples have provided insight into the nature and occurrence of hydrous phases such as amphibole, mica, and chlorite, and have provided constraints on the capacity of nominally anhydrous minerals (NAMs) such as olivine, pyroxenes, and garnet to contain "water" by a variety of substitution mechanisms. Experimental studies on mantle-derived magmas have provided constraints on volatile contents in their source regions. Other studies have constrained the pressure, temperature, and composition conditions over which hydrous phases are stable in the mantle.Fundamental questions remain about the geochemical cycling of volatiles in the mantle, and between the mantle and the surface. Much attention has focused on the capability of hydrous phases such as amphibole, mica, serpentine, chlorite, and a family of "dense hydrous magnesian silicates" (DHMSs) to act as carriers of water in subducting slabs back into the mantle. It has been clear since the work of Ito et al. (1983) that there is a discrepancy between the amount of volatiles subducted into the mantle and those returned to the surface by arc magmatism. A recent overview of volatile cycling in subduction systems by Bebout (1996) suggests that 5-15% of the H2

  2. Level Shifts in Volatility and the Implied-Realized Volatility Relation

    DEFF Research Database (Denmark)

    Christensen, Bent Jesper; de Magistris, Paolo Santucci

    to the multivariate case of the univariate level shift technique by Lu and Perron (2008). An application to the S&P500 index and a simulation experiment show that the recently documented empirical properties of strong persistence in volatility and forecastability of future realized volatility from current implied...... volatility, which have been interpreted as long memory (or fractional integration) in volatility and fractional cointegration between implied and realized volatility, are accounted for by occasional common level shifts....

  3. Evidence that the factor used by the tapeworm, Hymenolepis diminuta, to direct the foraging of its intermediate host, Tribolium confusum, is a volatile attractant.

    Science.gov (United States)

    Evans, W S; Wong, A; Hardy, M; Currie, R W; Vanderwel, D

    1998-12-01

    We have previously demonstrated that flour beetles, Tribolium confusum, are more attracted to the feces from rats with patent Hymenolepis diminuta infections than to feces from uninfected rats. The objective of this study was to determine if this effect is due to a volatile attractant. Volatile substances emitted by feces from H. diminuta-infected rats or from uninfected controls were collected by aspirating fresh rat feces, while trapping the volatiles on Porapak Q (a solid adsorbant). The volatiles were eluted from the Porapak Q with diethyl ether, and the relative attractancy of the volatiles to prestarved beetles was assessed by bioassay. More beetles were attracted to volatiles of feces from infected rats than to volatiles of feces from uninfected controls (Pconfusum) through the use of attractive, volatile material released from the feces of its definitive host.

  4. MELTER OFF-GAS FLAMMABILITY ASSESSMENT FOR DWPF ALTERNATE REDUCTANT FLOWSHEET OPTIONS

    Energy Technology Data Exchange (ETDEWEB)

    Choi, A.

    2011-07-08

    Glycolic acid and sugar are being considered as potential candidates to substitute for much of the formic acid currently being added to the Defense Waste Processing Facility (DWPF) melter feed as a reductant. A series of small-scale melter tests were conducted at the Vitreous State Laboratory (VSL) in January 2011 to collect necessary data for the assessment of the impact of these alternate reductants on the melter off-gas flammability. The DM10 melter with a 0.021 m{sup 2} melt surface area was run with three different feeds which were prepared at SRNL based on; (1) the baseline formic/nitric acid flowsheet, (2) glycolic/formic/nitric acid flowsheet, and (3) sugar/formic/nitric acid flowsheet - these feeds will be called the baseline, glycolic, and sugar flowsheet feeds, respectively, hereafter. The actual addition of sugar to the sugar flowsheet feed was made at VSL before it was fed to the melter. For each feed, the DM10 was run under both bubbled (with argon) and non-bubbled conditions at varying melter vapor space temperatures. The goal was to lower its vapor space temperature from nominal 500 C to less than 300 C at 50 C increments and maintain steady state at each temperature at least for one hour, preferentially for two hours, while collecting off-gas data including CO, CO{sub 2}, and H{sub 2} concentrations. Just a few hours into the first test with the baseline feed, it was discovered that the DM10 vapor space temperature would not readily fall below 350 C simply by ramping up the feed rate as the test plan called for. To overcome this, ambient air was introduced directly into the vapor space through a dilution air damper in addition to the natural air inleakage occurring at the operating melter pressure of -1 inch H{sub 2}O. A detailed description of the DM10 run along with all the data taken is given in the report issued by VSL. The SRNL personnel have analyzed the DM10 data and identified 25 steady state periods lasting from 32 to 92 minutes for all

  5. Chemical composition of the volatile oil from Zanthoxylum avicennae and antimicrobial activities and cytotoxicity

    Directory of Open Access Journals (Sweden)

    Yin Lin

    2014-01-01

    Full Text Available Background: Through literature retrieval, there has been no report on the research of the chemical components in Zanthoxylum avicennae (Lam. DC. This paper extracted and determined the chemical components of the volatile oil in Z. avicennae, and at the same time, measured and evaluated the bioactivity of the volatile oil in Z. avicennae. Materials and Methods: We extract the volatile oil in Z. avicennae by steam distillation method, determined the chemical composition of the volatile oil by GC-MS coupling technique, and adopt the peak area normalization method to measured the relative percentage of each chemical composition in the volatile oil. Meanwhile, we use the Lethal-to-prawn larva bioactivity experiment to screen the cytotoxicity activities of the volatile oil in Z. avicennae, and using the slanting test-tube experiment to determine and evaluate its antibacterial activities in vitro for the eight kinds of plant pathogenic fungi in the volatile oil of the Z. avicennae. Results: The results show that 68 kinds of compounds are determined from the volatile oil of Z. avicennae. The determined part takes up 97.89% of the total peak area. The main ingredients in the volatile oil of Z. avicennae are sesquiterpenoids and monoterpene. The test results show that the volatile oil in Z. avicennae has strong antibacterial activities and cytotoxicity, with the strongest antibacterial activity against the Rhizoctonia solani AG1-1A. Conclusion: This research results will provide reference data for understanding the chemical composition of the volatile oil in the aromatic plant of Z. avicennae and its bioactivity, and for its further development and application.

  6. From Fireproof Desert to Flammable Grassland: Buffelgrass Invasion in the Sonoran Desert

    Science.gov (United States)

    Betancourt, J. L.

    2007-12-01

    Only a few decades ago, the Sonoran Desert of northwestern Mexico and southern Arizona was considered mostly fireproof, a case of not enough fine fuel to connect the dominant shrubs and cacti. This has changed with invasions by non-native, winter annual and summer-flower perennial grasses that are rapidly transforming fireproof desert into flammable grassland. Of particular concern is buffelgrass, Pennisetum ciliare, a fire-prone and invasive African perennial grass that has already converted millions of hectares across Sonora since the mid-1960s and has made quick headway in southern and central Arizona beginning in the 1980s. Near Tucson and Phoenix, AZ, buffelgrass invasion is proceeding exponentially, with population expansion (and the costs of mitigation) more than doubling every year. As this conversion progresses, there will be increased fire risks, lost tourist revenue, diminished property values, insurmountable setbacks to conservation efforts, and the threat of large ignition fronts in desert valleys routinely spreading into the mountains. Although somewhat belated, an integrated, multi-jurisdictional effort is being organized to reduce ecological and economic impacts. My presentation will summarize the history and context of buffelgrass introduction and invasion, the disconnect in attitudes and policies across state and international boundaries, ongoing management efforts, the role of science and responsibilities of scientists, accelerated spread with changing climate, and impacts to regional ecosystems and economies. This narrative may serve as a template for other semi-arid lands where buffelgrass and similar grasses have become invasive, including Australia, South America, and many islands in the Pacific Ocean (including Hawaii), Indian Ocean, and Caribbean Sea.

  7. The economic value of realized volatility

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Feunou, Bruno; Jacobs, Kris

    2014-01-01

    Many studies have documented that daily realized volatility estimates based on intraday returns provide volatility forecasts that are superior to forecasts constructed from daily returns only. We investigate whether these forecasting improvements translate into economic value added. To do so, we...... develop a new class of affine discrete-time option valuation models that use daily returns as well as realized volatility. We derive convenient closed-form option valuation formulas, and we assess the option valuation properties using Standard & Poor’s (S&P) 500 return and option data. We find...... that realized volatility reduces the pricing errors of the benchmark model significantly across moneyness, maturity, and volatility levels....

  8. Solid phase microextraction for profiling volatile compounds in liquered white wines

    Directory of Open Access Journals (Sweden)

    Henryk H. Jeleń

    2010-03-01

    Full Text Available Background. Profile of volatile compounds is a distinct feature of wine, which is dependent on the type of wine, grapes, fermentation and ageing processes. Profiling volatile compounds in wine using fast method provides information on major groups of compounds and can be used for classification/differentiation purposes. Solid phase microextraction (SPME was used for the profiling of volatile compounds in liquered white wines in this study. Material and methods. Different fibers were tested for this purpose: PDMS, Carboxene/ PDMS, Carboxene/DVB/PDMS, Polyacrylate, Divinylbenzene/PDMS. Different times were compared to optimize extraction process. Profile and amount of volatile compounds extracted by SPME fiber was compared for eight liquered white wines. Results. Carboxene/DVB/PDMS showed the highest efficiency in extracting higher alcohols, esters, carbonyls and terpenes. Of tested extraction times ranging from 5 to 30 min. 20 minutes was chosen providing sufficient peak responses. Using SPME total amount of volatile compounds in eight liquered wines was compared – Riversaltes, Offley Porto and Jutrzenka having the highest amount of adsorbed volatiles. Profiles of volatiles of analysed wines revealed that dominating compounds in 6 wines were esters, followed by higher alcohols, two analysed Muscat wines had high terpene contents compared to remaining wines. Conclusion. SPME can be used for relatively fast profiling of wine volatiles, that can be used for wines classification.  

  9. Arbitrage and Volatility in Chinese Stock's Markets

    Science.gov (United States)

    Lu, Shu Quan; Ito, Takao; Zhang, Jianbo

    From the point of view of no-arbitrage pricing, what matters is how much volatility the stock has, for volatility measures the amount of profit that can be made from shorting stocks and purchasing options. With the short-sales constraints or in the absence of options, however, high volatility is likely to mean arbitrage from stock market. As emerging stock markets for China, investors are increasingly concerned about volatilities of Chinese two stock markets. We estimate volatility's models for Chinese stock markets' indexes using Markov chain Monte Carlo (MCMC) method and GARCH. We find that estimated values of volatility parameters are very high for all data frequencies. It suggests that stock returns are extremely volatile even at long term intervals in Chinese markets. Furthermore, this result could be considered that there seems to be arbitrage opportunities in Chinese stock markets.

  10. Forecasting volatility of crude oil markets

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Sang Hoon [Department of Business Administration, Gyeongsang National University, Jinju, 660-701 (Korea); Kang, Sang-Mok; Yoon, Seong-Min [Department of Economics, Pusan National University, Busan, 609-735 (Korea)

    2009-01-15

    This article investigates the efficacy of a volatility model for three crude oil markets - Brent, Dubai, and West Texas Intermediate (WTI) - with regard to its ability to forecast and identify volatility stylized facts, in particular volatility persistence or long memory. In this context, we assess persistence in the volatility of the three crude oil prices using conditional volatility models. The CGARCH and FIGARCH models are better equipped to capture persistence than are the GARCH and IGARCH models. The CGARCH and FIGARCH models also provide superior performance in out-of-sample volatility forecasts. We conclude that the CGARCH and FIGARCH models are useful for modeling and forecasting persistence in the volatility of crude oil prices. (author)

  11. Chirospecific analysis of plant volatiles

    Energy Technology Data Exchange (ETDEWEB)

    Tkachev, A V [N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch of the Russian Academy of Sciences, Novosibirsk (Russian Federation)

    2007-10-31

    Characteristic features of the analysis of plant volatiles by enantioselective gas (gas-liquid) chromatography and gas chromatography/mass spectrometry are discussed. The most recent advances in the design of enantioselective stationary phases are surveyed. Examples of the preparation of the most efficient phases based on modified cyclodextrins are given. Current knowledge on the successful analytical resolution of different types of plant volatiles (aliphatic and aromatic compounds and mono-, sesqui- and diterpene derivatives) into optical antipodes is systematically described. Chiral stationary phases used for these purposes, temperature conditions and enantiomer separation factors are summarised. Examples of the enantiomeric resolution of fragrance compounds and components of plant extracts, wines and essential oils are given.

  12. Chirospecific analysis of plant volatiles

    Science.gov (United States)

    Tkachev, A. V.

    2007-10-01

    Characteristic features of the analysis of plant volatiles by enantioselective gas (gas-liquid) chromatography and gas chromatography/mass spectrometry are discussed. The most recent advances in the design of enantioselective stationary phases are surveyed. Examples of the preparation of the most efficient phases based on modified cyclodextrins are given. Current knowledge on the successful analytical resolution of different types of plant volatiles (aliphatic and aromatic compounds and mono-, sesqui- and diterpene derivatives) into optical antipodes is systematically described. Chiral stationary phases used for these purposes, temperature conditions and enantiomer separation factors are summarised. Examples of the enantiomeric resolution of fragrance compounds and components of plant extracts, wines and essential oils are given.

  13. Investigation of flammable gas and thermal safety issues for retrieval of waste from Tank 241-AN-105

    Energy Technology Data Exchange (ETDEWEB)

    Caley, S.M.; Stewart, C.W.; Antoniak, Z.I.; Cuta, J.M.; Mahoney, L.A.; Panisko, F.E.

    1998-09-01

    The primary purpose of this report is to identify and resolve some of the flammable gas and thermal safety issues potentially associated with the retrieval of waste from Tank 241-AN-105 (AN-105), which is the first double-shell tank scheduled for waste retrieval at Hanford. The planned retrieval scenario includes the following steps in AN-105: (1) degas the tank using two submerged mixing pumps, (2) turn off the mixer pump(s) and allow any suspended solids to settle, (3) decant the supernatant to the intermediate feed staging tank(s) (IFSTs) (AP-102 and/or AP-104) using water/caustic dilution at the transfer pump inlet, (4) add the remaining dilution water/caustic to the slurry remaining in AN-105, (5) mix the tank with the mixer pump(s) until the soluble solids dissolve, (6) turn off the mixer pump(s) and let the insoluble solids settle, and (7) decant the new supernatant to the IFST(s), leaving the insoluble solids behind. Three waste retrieval safety issues are addressed in this report. They are (1) the controlled degassing of AN-105 to ensure that the headspace remains <25% of the lower flammability limit (LFL), (2) an assessment of how dissolved gas (mainly ammonia) released during the transfer of the supernatant in AN-105 to the IFSTs and the water/caustic dilution of the remaining slurry in AN-105 will affect the flammability in these tanks; and (3) an assessment of the maximum waste temperatures that might occur in AN-105 during retrieval operations.

  14. Volatiles in Inter-Specific Bacterial Interactions.

    Science.gov (United States)

    Tyc, Olaf; Zweers, Hans; de Boer, Wietse; Garbeva, Paolina

    2015-01-01

    The importance of volatile organic compounds for functioning of microbes is receiving increased research attention. However, to date very little is known on how inter-specific bacterial interactions effect volatiles production as most studies have been focused on volatiles produced by monocultures of well-described bacterial genera. In this study we aimed to understand how inter-specific bacterial interactions affect the composition, production and activity of volatiles. Four phylogenetically different bacterial species namely: Chryseobacterium, Dyella, Janthinobacterium, and Tsukamurella were selected. Earlier results had shown that pairwise combinations of these bacteria induced antimicrobial activity in agar media whereas this was not the case for monocultures. In the current study, we examined if these observations were also reflected by the production of antimicrobial volatiles. Thus, the identity and antimicrobial activity of volatiles produced by the bacteria were determined in monoculture as well in pairwise combinations. Antimicrobial activity of the volatiles was assessed against fungal, oomycetal, and bacterial model organisms. Our results revealed that inter-specific bacterial interactions affected volatiles blend composition. Fungi and oomycetes showed high sensitivity to bacterial volatiles whereas the effect of volatiles on bacteria varied between no effects, growth inhibition to growth promotion depending on the volatile blend composition. In total 35 volatile compounds were detected most of which were sulfur-containing compounds. Two commonly produced sulfur-containing volatile compounds (dimethyl disulfide and dimethyl trisulfide) were tested for their effect on three target bacteria. Here, we display the importance of inter-specific interactions on bacterial volatiles production and their antimicrobial activities.

  15. Volatiles in inter-specific bacterial interactions

    Directory of Open Access Journals (Sweden)

    Olaf eTyc

    2015-12-01

    Full Text Available The importance of volatile organic compounds for functioning of microbes is receiving increased research attention. However, to date very little is known on how inter-specific bacterial interactions effect volatiles production as most studies have been focused on volatiles produced by monocultures of well described bacterial genera. In this study we aimed to understand how inter-specific bacterial interactions affect the composition, production and activity of volatiles. Four phylogenetically different bacterial species namely: Chryseobacterium, Dyella, Janthinobacterium and Tsukamurella were selected. Earlier results had shown that pairwise combinations of these bacteria induced antimicrobial activity in agar media whereas this was not the case for monocultures. In the current study, we examined if these observations were also reflected by the production of antimicrobial volatiles. Thus, the identity and antimicrobial activity of volatiles produced by the bacteria were determined in monoculture as well in pairwise combinations. Antimicrobial activity of the volatiles was assessed against fungal, oomycetal and bacterial model organisms. Our results revealed that inter-specific bacterial interactions affected volatiles blend composition. Fungi and oomycetes showed high sensitivity to bacterial volatiles whereas the effect of volatiles on bacteria varied between no effects, growth inhibition to growth promotion depending on the volatile blend composition. In total 35 volatile compounds were detected most of which were sulfur-containing compounds. Two commonly produced sulfur-containing volatile compounds (dimethyl disulfide and dimethyl trisulfide were tested for their effect on three target bacteria. Here we display the importance of inter-specific interactions on bacterial volatiles production and their antimicrobial activities.

  16. Money, banks and endogenous volatility

    OpenAIRE

    Pere Gomis-Porqueras

    2000-01-01

    In this paper I consider a monetary growth model in which banks provide liquidity, and the government fixes a constant rate of money creation. There are two underlying assets in the economy, money and capital. Money is dominated in rate of return. In contrast to other papers with a larger set of government liabilities, I find a unique equilibrium when agents' risk aversion is moderate. However, indeterminacies and endogenous volatility can be observed when agents are relatively risk averse.

  17. Volatility at Karachi Stock Exchange

    OpenAIRE

    Aslam Farid; Javed Ashraf

    1995-01-01

    Frequent “crashes” of the stock market reported during the year 1994 suggest that the Karachi bourse is rapidly converting into a volatile market. This cannot be viewed as a positive sign for this developing market of South Asia. Though heavy fluctuations in stock prices are not an unusual phenomena and it has been observed at almost all big and small exchanges of the world. Focusing on the reasons for such fluctuations is instructive and likely to have important policy implications. Proponen...

  18. Flue-Gas Desulfurization Gypsum Effects on Urea-Degrading Bacteria and Ammonia Volatilization From Broiler Litter

    Science.gov (United States)

    A major concern of the broiler industry is the volatilization of ammonia (NH3) from the mixture of bedding material and broiler excretion that covers the floor of broiler houses. Gypsum has been proposed as a litter amendment to reduce NH3 volatilization, but reports of NH3 abatement vary among stu...

  19. Volatile compounds in the thermoplastic extrusion of bovine rumen

    Directory of Open Access Journals (Sweden)

    Ana Carolina Conti e Silva

    2008-01-01

    Full Text Available The volatile compounds of raw and extruded bovine rumen, extracted by dynamic headspace, were separated by gas chromatography and analyzed by GC-MS. Raw and extruded materials presented thirty-two volatile compounds. The following compounds were identified in raw bovine rumen: heptane, 1-heptene, 4-methyl-2-pentanone, toluene, hexanal, ethyl butyrate, o-xylene, m-xylene, p-xylene, heptanal, limonene, nonanal, dodecane, tridecane, tetradecane, pentadecane, hexadecane, heptadecane and octadecane. The following compounds were identified in the extruded material: 1-heptene, 2,4-dimethylhexane, toluene, limonene, undecane, tetradecane, pentadecane, hexadecane, heptadecane, octadecane and nonadecane. Mass spectra of some unidentified compounds indicated the presence of hydrocarbons with branched chains or cyclic structure.

  20. Human skin volatiles: a review.

    Science.gov (United States)

    Dormont, Laurent; Bessière, Jean-Marie; Cohuet, Anna

    2013-05-01

    Odors emitted by human skin are of great interest to biologists in many fields; applications range from forensic studies to diagnostic tools, the design of perfumes and deodorants, and the ecology of blood-sucking insect vectors of human disease. Numerous studies have investigated the chemical composition of skin odors, and various sampling methods have been used for this purpose. The literature shows that the chemical profile of skin volatiles varies greatly among studies, and the use of different sampling procedures is probably responsible for some of these variations. To our knowledge, this is the first review focused on human skin volatile compounds. We detail the different sampling techniques, each with its own set of advantages and disadvantages, which have been used for the collection of skin odors from different parts of the human body. We present the main skin volatile compounds found in these studies, with particular emphasis on the most frequently studied body regions, axillae, hands, and feet. We propose future directions for promising experimental studies on odors from human skin, particularly in relation to the chemical ecology of blood-sucking insects.

  1. Preparation of Magnesium Hydroxide and Nanofiber Polymer Composites to Reduce the Flammability and Melt Dripping Behaviour of Polymers

    Directory of Open Access Journals (Sweden)

    S. S. Raza

    2014-12-01

    Full Text Available Nanoscale alumina fibers reduce the flammability and melt dripping behaviour of polymers. Magnesium hydroxide breaks the agglomerates by generating shear and iterative forces. Mixing was done with Brabender Plasticoder. The temperature and time of mixing greatly affects the mixing behaviour. At higher temperatures blow holes were observed. By increasing the mixing time agglomerates were broken to a greater extent. Different concentrations of nanofibers, Magnesium hydroxide and surface treatments are used to investigate the properties of polymer. Thermogravimetric analysis (TGA, optical microscopy and flame test was done to see the effect of different parameters on mixing and flame retardancy behaviour.

  2. Safer Aviation Materials Tested

    Science.gov (United States)

    Palaszewski, Bryan A.

    2001-01-01

    A series of thermally stable polymer samples were tested. These materials are called low heat release materials and are designed for aircraft interior decorative materials. The materials are designed to give off a minimum amount of noxious gases when heated, which increases the possibility that people can escape from a burning aircraft. New cabin materials have suitably low heat release so that fire does not spread, toxic chemicals are not given off, and the fire-emergency escape time for crew and passengers is lengthened. These low heat-release materials have a variety of advantages and applications: interiors for ground-based facilities, interiors of space vehicles, and many commercial fire-protection environments. A microscale combustion calorimeter at the Federal Aviation Administration's (FAA) Technical Center tested NASA Langley Research Center materials samples. The calorimeter is shown. A sharp, quantitative, and reproducible heat-release-rate peak is obtained in the microscale heat-release-rate test. The newly tested NASA materials significantly reduced the heat release capacity and total heat release. The thermal stability and flammability behavior of the samples was very good. The new materials demonstrated a factor of 4 reduction in total heat release over ULTEM (a currently used material). This information is provided in the following barchart. In other tests, the materials showed greater than a factor 9 reduction in heat-release capacity over ULTEM. The newly tested materials were developed for low dielectric constant, low color, and good solubility. A scale up of the material samples is needed to determine the repeatability of the performance in larger samples. Larger panels composed of the best candidate materials will be tested in a larger scale FAA Technical Center fire facility. The NASA Glenn Research Center, Langley (Jeff Hinkley), and the FAA Technical Center (Richard Lyon) cooperatively tested these materials for the Accident Mitigation

  3. Volatile and non-volatile/semi-volatile compounds and in vitro bioactive properties of Chilean Ulmo (Eucryphia cordifolia Cav.) honey.

    Science.gov (United States)

    Acevedo, Francisca; Torres, Paulina; Oomah, B Dave; de Alencar, Severino Matias; Massarioli, Adna Prado; Martín-Venegas, Raquel; Albarral-Ávila, Vicenta; Burgos-Díaz, César; Ferrer, Ruth; Rubilar, Mónica

    2017-04-01

    Ulmo honey originating from Eucryphia cordifolia tree, known locally in the Araucania region as the Ulmo tree is a natural product with valuable nutritional and medicinal qualities. It has been used in the Mapuche culture to treat infections. This study aimed to identify the volatile and non-volatile/semi-volatile compounds of Ulmo honey and elucidate its in vitro biological properties by evaluating its antioxidant, antibacterial, antiproliferative and hemolytic properties and cytotoxicity in Caco-2 cells. Headspace volatiles of Ulmo honey were isolated by solid-phase microextraction (SPME); non-volatiles/semi-volatiles were obtained by removing all saccharides with acidified water and the compounds were identified by GC/MS analysis. Ulmo honey volatiles consisted of 50 compounds predominated by 20 flavor components. Two of the volatile compounds, lyrame and anethol have never been reported before as honey compounds. The non-volatile/semi-volatile components of Ulmo honey comprised 27 compounds including 13 benzene derivatives accounting 75% of the total peak area. Ulmo honey exhibited weak antioxidant activity but strong antibacterial activity particularly against gram-negative bacteria and methicillin-resistant Staphylococcus aureus (MRSA), the main strain involved in wounds and skin infections. At concentrations >0.5%, Ulmo honey reduced Caco-2 cell viability, released lactate dehydrogenase (LDH) and increased reactive oxygen species (ROS) production in a dose dependent manner in the presence of foetal bovine serum (FBS). The wide array of volatile and non-volatile/semi-volatile constituents of Ulmo honey rich in benzene derivatives may partly account for its strong antibacterial and antiproliferative properties important for its therapeutic use. Our results indicate that Ulmo honey can potentially inhibit cancer growth at least partly by modulating oxidative stress. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Analysis of Volatile Markers for Virgin Olive Oil Aroma Defects by SPME-GC/FID: Possible Sources of Incorrect Data.

    Science.gov (United States)

    Oliver-Pozo, Celia; Aparicio-Ruiz, Ramón; Romero, Inmaculada; García-González, Diego L

    2015-12-09

    The need to explain virgin olive oil (VOO) aroma descriptors by means of volatiles has raised interest in applying analytical techniques for trapping and quantitating volatiles. Static headspace sampling with solid phase microextraction (SPME) as trapping material is one of the most applied solutions for analyzing volatiles. The use of an internal standard and the determination of the response factors of the main volatiles seem to guarantee the correct determination of volatile concentrations in VOOs by SPME-GC/FID. This paper, however, shows that the competition phenomena between volatiles in their adsorption to the SPME fiber, inherent in static headspace sampling, may affect the quantitation. These phenomena are more noticeable in the particular case of highly odorant matrices, such as rancid and vinegary VOOs with high intensity of defect. The competition phenomena can modify the measurement sensitivity, which can be observed in volatile quantitation as well as in the recording of internal standard areas in different matrices. This paper analyzes the bias of the peak areas and concentrations of those volatiles that are markers for each sensory defect of VOOs (rancid, vinegary, musty, and fusty) when the intensity and complexity of aroma are increased. Of the 17 volatile markers studied in this work, 10 presented some anomalies in the quantitation in highly odorant matrices due the competition phenomena. However, quantitation was not affected in the concentration ranges at which each volatile marker is typically found in the defective oils they were characteristic of, validating their use as markers.

  5. Geochemical Constraints for Mechanisms of Planetary Differentiation and Volatile Depletion

    OpenAIRE

    Dhaliwal, Jasmeet Kaur

    2016-01-01

    The evolution of the terrestrial planets involved a range of complex processes, including accretion, core formation, post-core formation accretion, mantle differentiation and volatile depletion. The earliest processes of accretion and core formation have largely been overprinted on Earth and Mars, but can be investigated using geochemical measurements of extraterrestrial materials. Highly siderophile elements (HSE; Os, Ir, Ru, Rh, Pt, Pd, Re, Au) preferentially partition into metal phases an...

  6. Computing with volatile memristors: an application of non-pinched hysteresis

    Science.gov (United States)

    Pershin, Y. V.; Shevchenko, S. N.

    2017-02-01

    The possibility of in-memory computing with volatile memristive devices, namely, memristors requiring a power source to sustain their memory, is demonstrated theoretically. We have adopted a hysteretic graphene-based field emission structure as a prototype of a volatile memristor, which is characterized by a non-pinched hysteresis loop. A memristive model of the structure is developed and used to simulate a polymorphic circuit implementing stateful logic gates, such as the material implication. Specific regions of parameter space realizing useful logic functions are identified. Our results are applicable to other realizations of volatile memory devices, such as certain NEMS switches.

  7. Earth's moderately volatile element composition may not be chondritic: Evidence from In, Cd and Zn

    Science.gov (United States)

    Wang, Zaicong; Laurenz, Vera; Petitgirard, Sylvain; Becker, Harry

    2016-02-01

    Current models assume that siderophile volatile elements (SVE) are depleted in bulk Earth to the same extent as lithophile elements of similar volatility. The observed additional depletion of many SVE relative to lithophile elements in the bulk silicate Earth (BSE) is ascribed to partitioning of SVE into Earth's core. However, the assumption of similar volatility of moderately volatile elements during Earth formation processes as in solar gas is quite uncertain. Here, these assumptions will be tested by assessing abundances and ratios of indium and cadmium in the BSE using new data on mantle rocks, and the application of high- and low-pressure-temperature metal-silicate partitioning data. New bulk rock abundance data of In and Cd obtained on bulk rocks of peridotite tectonites and xenoliths by isotope dilution refine previous results inferred from basalts and in-situ analyses of silicate minerals in peridotite xenoliths. The CI chondrite-normalized abundance of In in the BSE is similar to zinc and is 3-4 times higher than Cd. New and published low- and high-P-T metal-silicate partitioning data indicate that, during core formation at a range of conditions, In is always more siderophile than Zn and Cd. Adding the fraction of these elements in Earth's core to the BSE results in bulk Earth compositions that yield higher CI chondrite normalized abundances of In in the bulk Earth compared to Zn and Cd. Because In is more volatile than Zn and Cd in gas of solar composition, suprachondritic In/Zn and In/Cd in the bulk Earth suggest that during formation of Earth or its building materials, the volatilities of these elements and perhaps other volatile elements likely have changed significantly (i.e. In became less volatile). The results also suggest that known carbonaceous chondrites likely did not deliver the main volatile element-rich fraction of the Earth. Various arguments suggest that the loss of moderately volatile elements during planetary accretion should be limited

  8. NASA-STD-6016 Standard Materials and Processes Requirements for Spacecraft

    Science.gov (United States)

    Hirsch, David B.

    2009-01-01

    The standards for materials and processes surrounding spacecraft are discussed. Presentation focused on minimum requirements for Materials and Processes (M&P) used in design, fabrication, and testing of flight components for NASA manned, unmanned, robotic, launch vehicle, lander, in-space and surface systems, and spacecraft program/project hardware elements.Included is information on flammability, offgassing, compatibility requirements, and processes; both metallic and non-metallic materials are mentioned.

  9. Comparison of Methanol and Tetraglyme as Extraction Solvents for Determination of Volatile Organics in Soil

    Science.gov (United States)

    1987-11-01

    determining volatile organics in soil can be classified into thefollowing groups: 1. Static or dynamic headspace analysis 2. Solvent extraction-direct...methods based on the dynamic headspace method whereby the volatiles are stripped from a soil/water slurry using a conventional purge-and-trap instrument...651. Brazell, R.S. and MP. Maskarinec (1981) Dynamic headspace analysis of solid waste materials. Journal of High Resolution Chromatography and

  10. Efficiency Assessment of Using Flammable Compounds from Water Treatment and Methanol Production Waste for Plasma Synthesis of Iron-Containing Pigments

    Science.gov (United States)

    Shekhovtsova, Anastasia P.; Karengin, Alexander G.

    2016-08-01

    This article describes the possibility of applying the low-temperature plasma for obtaining iron-containing pigments from water purification and flammable methanol production waste. In this paper were calculated combustion parameters of water-saltorganic compositions (WSOC) with different consists. Authors determined the modes of energy- efficient processing of the previously mentioned waste in an air plasma. Having considered the obtained results there were carried out experiments with flammable dispersed water-saltorganic compositions on laboratory plasma stand. All the experimental results are confirmed by calculations.

  11. Safety Strategies in Flammable and Combustible Place%浅议易燃易爆场所消防安全对策

    Institute of Scientific and Technical Information of China (English)

    田颍

    2011-01-01

    According to the present situation of fire in flammable and explosive place, analyzed the fire characteristics and occurrence regularity in flammable and explosive place, discussed the formation reasons, and explored scientific reasonable and operable measures of fire and explosion.%本文根据易燃易爆场所的火灾现状,分析易燃易爆场所的火灾特点,发生规律,探讨其火灾形成原因,探讨科学合理并具有可操作性的防火防爆对策.

  12. Program plan for evaluation and remediation of the generation and release of flammable gases in Hanford Site waste tanks

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, G.D. (comp.)

    1991-08-01

    This program plan describes the activities being conducted for the resolution of the flammable gas problem that is associated with 23 high-level waste tanks at the Hanford Site. The classification of the wastes in all of these tanks is not final and some wastes may not be high-level wastes. However, until the characterization and classification is complete, all the tanks are treated as if they contain high-level waste. Of the 23 tanks, Tank 241-SY-101 (referred to as Tank 101-SY) has exhibited significant episodic releases of flammable gases (hydrogen and nitrous oxide) for the past 10 years. The major near-term focus of this program is for the understanding and stabilization of this tank. An understanding of the mechanism for gas generation and the processes for the episodic release will be obtained through sampling of the tank contents, laboratory studies, and modeling of the tank behavior. Additional information will be obtained through new and upgraded instrumentation for the tank. A number of remediation, or stabilization, concepts will be evaluated for near-term (2 to 3 years) applications to Tank 101-SY. Detailed safety assessments are required for all activities that will occur in the tank (sampling, removal of equipment, and addition of new instruments). This program plan presents a discussion of each task, provides schedules for near-term activities, and gives a summary of the expected work for fiscal years 1991, 1992, and 1993. 16 refs., 7 figs., 8 tabs.

  13. Differences in the risk profiles and risk perception of flammable liquid hazards in San Luis Potosi, Mexico

    Directory of Open Access Journals (Sweden)

    Claudia Yazmín Ortega Montoya

    2014-10-01

    Full Text Available The pace of urbanization and industrialization in developing countries is rapidly increasing. Unfortunately, regulatory and private-sector control of hazards has not always kept pace. This work identifies the level of emergency preparedness in chemical industries and evaluates the spatial distribution of hazards using a worst-case release scenario. Consequently, we identified potentially exposed urban communities and evaluated the social perception of a hazard. This research characterizes risk scenarios in a case study of the industrial area in San Luis Potosi, Mexico. Intervention zones of major concern are recognized when deficiencies in emergency preparedness join a poor social perception of hazards in communities that are potentially exposed. The worst-case scenario radii of flammable chemicals range from 425 m to 733 m. Potentially exposed communities have a limited perception of chemical risk and no training in emergency response. Proximity to an industrial area influences communities towards a better recognition of hazards. However, communities far from the industrial area have higher exposure to low preparedness worst-case scenarios for flammable chemicals and have a larger level of vulnerability because of their lack of risk perception.

  14. Flammability of Cellulose-Based Fibers and the Effect of Structure of Phosphorus Compounds on Their Flame Retardancy

    Directory of Open Access Journals (Sweden)

    Khalifah A. Salmeia

    2016-08-01

    Full Text Available Cellulose fibers are promoted for use in various textile applications due their sustainable nature. Cellulose-based fibers vary considerably in their mechanical and flammability properties depending on their chemical composition. The chemical composition of a cellulose-based fiber is further dependent on their source (i.e., seed, leaf, cane, fruit, wood, bast, and grass. Being organic in nature, cellulose fibers, and their products thereof, pose considerable fire risk. In this work we have compared the flammability properties of cellulose fibers obtained from two different sources (i.e., cotton and peat. Compared to cotton cellulose textiles, peat-based cellulose textiles burn longer with a prominent afterglow which can be attributed to the presence of lignin in its structure. A series of phosphoramidates were synthesized and applied on both cellulose textiles. From thermogravimetric and pyrolysis combustion flow analysis of the treated cellulose, we were able to relate the flame retardant efficacy of the synthesized phosphorus compounds to their chemical structure. The phosphoramidates with methyl phosphoester groups exhibited higher condensed phase flame retardant effects on both types of cellulose textiles investigated in this study. In addition, the bis-phosphoramidates exhibited higher flame retardant efficacy compared to the mono-phosphoramidates.

  15. Altered community flammability in Florida's Apalachicola ravines and implications for the persistence of the endangered conifer Torreya taxifolia.

    Directory of Open Access Journals (Sweden)

    John M Mola

    Full Text Available Plant species and communities often reflect historic fire regimes via ecological and evolutionary responses to recurrent fires. Plant communities of the southeastern USA experience a wide array of fire regimes, perhaps nowhere more marked than the juxtaposition of fire-prone uplands and adjacent mesic ravines along Florida's Apalachicola River. The ravines contain many endemic and disjunct species, most notably the endangered endemic conifer Torreya taxifolia. A rapid decline in T. taxifolia over the past 60 years has been associated with widespread replacement by other tree species. To understand the changes accompanying the shift in ravine composition, we compared leaf litter flammability of nine historic and contemporary species. We measured maximum flame height, flame duration, smoldering duration, mass loss, absorptive capacity, and drying rate. Ordination and perMANOVA suggest the nine species segregated into three distinct groups: the fire-impeding T. taxifolia and Taxus floridana; an intermediate group of three deciduous angiosperms; and a mixed cluster of four flammable species. Results suggest T. taxifolia and T. floridana were fire-impeding species in these communities, while contemporary dominants burn similarly to the upslope pyric species. The increasing presence of fire-facilitating species may portend a shifting fire regime that further imperils T. taxifolia and other rare species in the formerly fire-safe ravines.

  16. Stability of Materials in High Temperature Water Vapor: SOFC Applications

    Science.gov (United States)

    Opila, E. J.; Jacobson, N. S.

    2010-01-01

    Solid oxide fuel cell material systems require long term stability in environments containing high-temperature water vapor. Many materials in fuel cell systems react with high-temperature water vapor to form volatile hydroxides which can degrade cell performance. In this paper, experimental methods to characterize these volatility reactions including the transpiration technique, thermogravimetric analysis, and high pressure mass spectrometry are reviewed. Experimentally determined data for chromia, silica, and alumina volatility are presented. In addition, data from the literature for the stability of other materials important in fuel cell systems are reviewed. Finally, methods for predicting material recession due to volatilization reactions are described.

  17. Volatile communication in plant-aphid interactions.

    Science.gov (United States)

    de Vos, Martin; Jander, Georg

    2010-08-01

    Volatile communication plays an important role in mediating the interactions between plants, aphids, and other organisms in the environment. In response to aphid infestation, many plants initiate indirect defenses through the release of volatiles that attract ladybugs, parasitoid wasps, and other aphid-consuming predators. Aphid-induced volatile release in the model plant Arabidopsis thaliana requires the jasmonate signaling pathway. Volatile release is also induced by infection with aphid-transmitted viruses. Consistent with mathematical models of optimal transmission, viruses that are acquired rapidly by aphids induce volatile release to attract migratory aphids, but discourage long-term aphid feeding. Although the ecology of these interactions is well-studied, further research is needed to identify the molecular basis of aphid-induced and virus-induced changes in plant volatile release.

  18. Qualitative characteristics and comparison of volatile fraction of vodkas made from different botanical materials by comprehensive two-dimensional gas chromatography and the electronic nose based on the technology of ultra-fast gas chromatography.

    Science.gov (United States)

    Wiśniewska, Paulina; Śliwińska, Magdalena; Dymerski, Tomasz; Wardencki, Waldemar; Namieśnik, Jacek

    2017-03-01

    Vodka is a spirit-based beverage made from ethyl alcohol of agricultural origin. At present, increasingly more vodka brands have labels that specify the botanical origin of the product. Until now, the techniques for distinguishing between vodkas of different botanical origin have been costly, time-consuming and insufficient for making a distinction between vodka produced from similar raw materials. Therefore, it is of utmost importance to find a fast and relatively inexpensive technique for conducting such tests. In the present study, we employed comprehensive two-dimensional gas chromatography (GC×GC) and an electronic nose based on the technology of ultra-fast GC with chemometric methods such as partial least square discriminant analysis, discriminant function analysis and soft independent modeling of class analogy. Both techniques allow a distinction between the vodkas produced from different raw materials. In the case of GC×GC, the differences between vodkas were more noticeable than in the analysis by electronic nose; however, the electronic nose allowed the significantly faster analysis of vodkas. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  19. The Study of Volatile Odor Material from Petrochemical Wastewater and Its Influence for Human Olfactory%石化废水中挥发性恶臭物质调查及其对人体嗅觉的影响

    Institute of Scientific and Technical Information of China (English)

    曾燕君; 周志军; 费蕾蕾

    2013-01-01

    The petrochemical wastewater can produce a mass of odor material .It can affect surroundings and it is harmful for human health .This paper studies releasing air sample from petrochemical wastewater .Tested the component of odors by machine ,and tested the odor concentration by olfaction experiment . Its can effectively recognize the kind、concentration of Odor material , and to the influence of human olfaction .%  石化废水可产生大量的挥发性恶臭物质,对周围环境与人群健康造成一定的影响。本文对石化废水挥发出来的恶臭物质进行了采样分析,采用仪器法对其恶臭物质的成分进行测定,同时采用人体嗅觉实验法测定其臭气浓度,从而有效识别挥发性恶臭物质的种类、浓度以及恶臭物质对人体嗅觉的影响。

  20. Volatile Survival on Near-Earth Asteroid 2008 EV5

    Science.gov (United States)

    Pohl, Leos; Britt, Daniel

    2016-10-01

    Asteroid 2008 EV5 is currently one of the possible targets of NASA Asteroid Redirect Mission (ARM). The objective of this mission is to recover a boulder from the surface of an asteroid. The selection of the final target requires understanding the physical characteristics of the asteroid such as the size-frequency distribution of boulders on the asteroid's surface, the presence of volatiles on the surface and below, the strength of the surface materials and the degree of their alteration. In our work, we focus on the second criterion, the possibility of volatiles presence on 2008 EV5. These can be expected to survive embedded within the crystal lattice of various phyllosilicates. The positive presence of volatiles on the surface of and inside the asteroid is important especially for ISRU hardware demonstrations. Spectral data suggest that 2008 EV5 is a member of CI chondrite group which is characterized by high phyllosilicate content (~70%) but there is also the possibility of it being a CR chondrite where the phyllosilicate content ranges significantly, from samples with negligible phyllosilicate content to samples with almost 70% phyllosilicate content. If the dynamical history of the asteroid brought it close enough to the Sun, the lattice of phyllosilicates could have disintegrated and released the volatiles (water) and the material could have dehydrated. The depth at which the dehydration might have taken place depends on the characteristic depth of heat wave penetration which in turn depends on material characteristics such as density, heat capacity and heat conductivity. These are in turn are closely linked to the porosity. The characteristic heat penetration depth also depends on orbital geometry and rotational and orbital periods. Besides the temperature itself, the dehydration is also affected by the duration of the crystal lattice breakup temperatures. We use thermal model in conjunction with available experimental data on the dehydration of clays and

  1. Milk Price Volatility and its Determinants

    OpenAIRE

    Dong, Fengxia; Du, Xiaodong; Gould, Brian W.

    2011-01-01

    The classified pricing of fluid milk under the Federal Milk Marketing Orders (FMMO) system combined with the cash settlement feature of Class IIII milk futures contracts generate a unique volatility pattern of these futures markets in the sense that the volatility gradually decreases as the USDA price announcement dates approaching in the month. Focusing on the evolution of volatility in Class III milk futures market, this study quantifies the relative importance of a set of factors driving m...

  2. DOES VOLATILITY RESPOND ASYMMETRIC TO PAST SHOCKS?

    OpenAIRE

    Claudiu Botoc

    2014-01-01

    The main aim of the paper is to examine if the stock market volatility exhibits asymmetric or an asymmetric response to past shocks, for certain CEE countries (Romania,Hungary, Bulgaria, Poland) over the period May 2004 - September 2014. For the stock marketsfrom East Europe the results are in line with the symmetric volatility, i.e. volatility is similaraffected by both positive and negative returns with the same magnitude. For the stock marketsfrom Central Europe the results are consistent ...

  3. The Determinants of Public Deficit Volatility

    OpenAIRE

    2009-01-01

    This paper empirically analyzes the political, institutional and economic sources of public deficit volatility. Using the system-GMM estimator for linear dynamic panel data models and a sample of 125 countries analyzed from 1980 to 2006, we show that higher public deficit volatility is typically associated with higher levels of political instability and less democracy. In addition, public deficit volatility tends to be magnified for small countries, in the outcome of hyper-inflation episodes ...

  4. Exchange Rate Volatility in BRICS Countries

    OpenAIRE

    2012-01-01

    This paper measures the impact of bilateral exchange rates, the world agricultural GDP and third-country exchange rate volatilities (Yen/USD and Euro/USD) on the BRICS agricultural exports using a vector autoregressive (VAR) model. Two measures of volatility are used: the standard deviation and the coefficient of variation of the rates of change of the real exchange rates. We found that most variables are integrated of order two except the third-country exchange rate volatilities which are st...

  5. Volatiles Which Increase Magma Viscosity

    Science.gov (United States)

    Webb, S.

    2015-12-01

    The standard model of an erupting volcano is one in which the viscosity of a decompressing magma increases as the volatiles leave the melt structure to form bubbles. It has now been observed that the addition of the "volatiles" P, Cl and F result in an increase in silicate melt viscosity. This observation would mean that the viscosity of selected degassing magmas would decrease rather than increase. Here we look at P, Cl and F as three volatiles which increase viscosity through different structural mechanisms. In all three cases the volatiles increase the viscosity of peralkaline composition melts, but appear to always decrease the viscosity of peraluminous melts. Phosphorus causes the melt to unmix into a Na-P rich phase and a Na-poor silicate phase. Thus as the network modifying Na (or Ca) are removed to the phosphorus-rich melt, the matrix melt viscosity increases. With increasing amounts of added phosphorus (at network modifying Na ~ P) the addition of further phosphorus causes a decrease in viscosity. The addition of chlorine to Fe-free aluminosilicate melts results in an increase in viscosity. NMR data on these glass indicates that the chlorine sits in salt-like structures surrounded by Na and/or Ca. Such structures would remove network-modifying atoms from the melt structure and thus result in an increase in viscosity. The NMR spectra of fluorine-bearing glasses shows that F takes up at least 5 different structural positions in peralkaline composition melts. Three of these positions should result in a decrease in viscosity due to the removal of bridging oxygens. Two of the structural positons of F, however, should result in an increase in viscosity as they require the removal of network-modifying atoms from the melt structure (with one of the structures being that observed for Cl). This would imply that increasing amounts of F might result in an increase in viscosity. This proposed increase in viscosity with increasing F has now been experimentally confirmed.

  6. Volatile halogenated hydrocarbons in foods

    Energy Technology Data Exchange (ETDEWEB)

    Miyahara, Makoto; Toyoda, Masatake; Saito, Yukio [National Institute of Health Services, Tokyo (Japan)] [and others

    1995-02-01

    Volatile halogenated organic compounds were determined in foods. Statistical treatment of the data for 13 sampled from 20 families living in suburban Tokyo (Saitama prefecture) indicated that the foods were contaminated by water pollution and/or substances introduced by the process of food production. Butter and margarine were contaminated by chlorinated ethylene, ethane, and related compounds released by dry cleaning and other operations. Soybean sprouts and tofu (soybean curd) contained chloroform and related trihalomethanes absorbed during the production process. 27 refs., 6 figs., 5 tabs.

  7. Volatile Constituents of Zhumaria Majdae

    Directory of Open Access Journals (Sweden)

    Yazdanparst

    1993-07-01

    Full Text Available Capillary gas chromatography mass spectrometry (GC- MS analyses of a sample of essential oil of zhumaria Linalool ned by simple water distillation of the pulverized air - dired leaves and flowers of the plant indicated that Linalool and comphor are the two major constituents of the volatile oil. Sylvestrene , y -terpinene, a- Pinene, b - carene, camphene, and Epiborneol constitute the other main components of the essential oil. The GC - MS chromatogram indicated the presence of more than fifty - components in the oil, most of them were present in trace amounts. In this study, the chemical structures of twenty of these consti tuents were elucidated using GC - MS analysis.

  8. Mars Accreted a Volatile Element-Depleted Late Veneer Indicating Early Delivery of Martian Volatiles

    Science.gov (United States)

    Becker, H.; Wang, Z.

    2016-08-01

    Chalcophile elements in SNC meteorites are used to constrain abundances in the Martian mantle. Strong depletion of Te relative to highly siderophile elements suggests a volatile element-depleted late veneer, requiring that volatiles arrived earlier.

  9. [Solidification of volatile oil with graphene oxide].

    Science.gov (United States)

    Yan, Hong-Mei; Jia, Xiao-Bin; Zhang, Zhen-Hai; Sun, E; Xu, Yi-Hao

    2015-02-01

    To evaluate the properties of solidifying volatile oil with graphene oxide, clove oil and zedoary turmeric oil were solidified by graphene oxide. The amount of graphene oxide was optimized with the eugenol yield and curcumol yield as criteria. Curing powder was characterized by differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). The effects of graphene oxide on dissolution in vitro and thermal stability of active components were studied. The optimum solidification ratio of graphene oxide to volatile oil was 1:1. Dissolution rate of active components had rare influence while their thermal stability improved after volatile oil was solidified. Solidifying herbal volatile oil with graphene oxide deserves further study.

  10. CAM Stochastic Volatility Model for Option Pricing

    Directory of Open Access Journals (Sweden)

    Wanwan Huang

    2016-01-01

    Full Text Available The coupled additive and multiplicative (CAM noises model is a stochastic volatility model for derivative pricing. Unlike the other stochastic volatility models in the literature, the CAM model uses two Brownian motions, one multiplicative and one additive, to model the volatility process. We provide empirical evidence that suggests a nontrivial relationship between the kurtosis and skewness of asset prices and that the CAM model is able to capture this relationship, whereas the traditional stochastic volatility models cannot. We introduce a control variate method and Monte Carlo estimators for some of the sensitivities (Greeks of the model. We also derive an approximation for the characteristic function of the model.

  11. Assessing Relative Volatility/Intermittency/Energy Dissipation

    DEFF Research Database (Denmark)

    Barndorff-Nielsen, Ole E.; Pakkanen, Mikko; Schmiegel, Jürgen

    We introduce the notion of relative volatility/intermittency and demonstrate how relative volatility statistics can be used to estimate consistently the temporal variation of volatility/intermittency even when the data of interest are generated by a non-semimartingale, or a Brownian semistationary...... process in particular. While this estimation method is motivated by the assessment of relative energy dissipation in empirical data of turbulence, we apply it also to energy price data. Moreover, we develop a probabilistic asymptotic theory for relative power variations of Brownian semistationary...... processes and Ito semimartingales and discuss how it can be used for inference on relative volatility/intermittency....

  12. Analysis of volatile nanoparticles emitted from diesel engine using TOF-SIMS and metal-assisted SIMS (MetA-SIMS)

    Science.gov (United States)

    Inoue, Masae; Murase, Atsushi; Yamamoto, Masami; Kubo, Shuichi

    2006-07-01

    Time-of-flight secondary ion mass spectrometry (TOF-SIMS) and metal-assisted SIMS (MetA-SIMS), which is TOF-SIMS analysis of metal-deposited sample surfaces, were applied to analyze small quantities of volatile nanoparticles emitted from a light-duty diesel engine under idling and deceleration conditions. We investigated nucleation materials, i.e., >C35 hydrocarbons, oxidation products, etc., which have lower volatility than the main components of volatile nanoparticles and control the formation of volatile nanoparticles. Oxygenated hydrocarbons were detected by TOF-SIMS in volatile nanoparticles under idling condition. Their relative intensities increased as particle diameter decreased. This resulted in the oxygenated hydrocarbons acting as nucleation materials for volatile nanoparticles under idling condition. High-molecular-weight hydrocarbons of greater than C35 were detected in volatile nanoparticles under deceleration condition by MetA-SIMS. It was concluded that the detected hydrocarbons originated in lubricants and acted as nucleation materials for volatile nanoparticles under deceleration condition. TOF-SIMS makes it possible to detect traces of low-volatility molecules due to its high-vacuum environment. MetA-SIMS is the only method of directly detecting high-molecular-weight hydrocarbons in small quantities of nanoparticles. TOF-SIMS and MetA-SIMS were proved to be useful tools for analyzing of the properties of volatile nanoparticles.

  13. Addressing airborne pollutant exposure at the source: an example of coal tar pitch volatiles (CTPV)

    CSIR Research Space (South Africa)

    Pretorius, Cecilia J

    2016-09-01

    Full Text Available Personal exposure concentrations to coal tar pitch volatiles (CTPV) were a concern in a workplace and the cause of the exposure was thought to be a particular raw material; as per the conventional belief. All the raw materials were analysed...

  14. Volatile accretion history of the terrestrial planets and dynamic implications

    Science.gov (United States)

    Albarède, Francis

    2009-10-01

    Accretion left the terrestrial planets depleted in volatile components. Here I examine evidence for the hypothesis that the Moon and the Earth were essentially dry immediately after the formation of the Moon-by a giant impact on the proto-Earth-and only much later gained volatiles through accretion of wet material delivered from beyond the asteroid belt. This view is supported by U-Pb and I-Xe chronologies, which show that water delivery peaked ~100million years after the isolation of the Solar System. Introduction of water into the terrestrial mantle triggered plate tectonics, which may have been crucial for the emergence of life. This mechanism may also have worked for the young Venus, but seems to have failed for Mars.

  15. Volatile phenols depletion in red wine using molecular imprinted polymers.

    Science.gov (United States)

    Teixeira, Rafaela; Dopico-García, Sonia; Andrade, Paula B; Valentão, Patrícia; López-Vilariño, José M; González-Rodríguez, Victoria; Cela-Pérez, Concepción; Silva, Luís R

    2015-12-01

    Wines can be modified by microorganisms during the ageing process, by producing off-flavours like volatile phenols (VP), leading to their deterioration, with great economic losses. The development of methods to recover wines affected by unwanted VP became an important target. Molecular imprinted polymers (MIPs) are synthetic materials with artificially-generated recognition sites for selective extraction of organic compounds from different matrices. In this work, two MIPs to remove unwanted VP from wines were developed and their effects were evaluated. Volatile compounds were determined by GC-FID and GC-IT/MS and phenolic compounds (non-coloured and anthocyanins) by HPLC-DAD. The treatment with MIP-4EG and MIP-4EP significantly reduced the content of 4-ethylguaiacol and 4-ethylphenol, respectively. Nevertheless, the changes observed in wine non-coloured and coloured phenolics and sensorial analysis indicate that their specificity and selectivity regarding off-flavours still needs to be improved.

  16. Volatile accretion history of the terrestrial planets and dynamic implications.

    Science.gov (United States)

    Albarède, Francis

    2009-10-29

    Accretion left the terrestrial planets depleted in volatile components. Here I examine evidence for the hypothesis that the Moon and the Earth were essentially dry immediately after the formation of the Moon-by a giant impact on the proto-Earth-and only much later gained volatiles through accretion of wet material delivered from beyond the asteroid belt. This view is supported by U-Pb and I-Xe chronologies, which show that water delivery peaked approximately 100 million years after the isolation of the Solar System. Introduction of water into the terrestrial mantle triggered plate tectonics, which may have been crucial for the emergence of life. This mechanism may also have worked for the young Venus, but seems to have failed for Mars.

  17. Option Pricing with Stochastic Volatility and Jump Diffusion Processes

    Directory of Open Access Journals (Sweden)

    Radu Lupu

    2006-05-01

    Full Text Available Option pricing by the use of Black Scholes Merton (BSM model is based on the assumption that asset prices have a lognormal distribution. In spite of the use of these models on a large scale, both by practioners and academics, the assumption of lognormality is rejected by the history of returns. The objective of this article is to present the methods that developed after the Black Scholes Merton environment and deals with the option pricing model adjustment to the empirical properties of asset returns. The main models that appeared after BSM allowed for special changes of the returns that materialized in jump-diffusion and stochastic volatility processes. The article presents the foundations of risk neutral options evaluation and the empirical evidence that fed the amendment of the lognormal assumption in the first part and shows the evaluation procedure under the assumption of stock prices following the jump-diffusion process and the stochastic volatility process.

  18. Option Pricing with Stochastic Volatility and Jump Diffusion Processes

    Directory of Open Access Journals (Sweden)

    Radu Lupu

    2006-03-01

    Full Text Available Option pricing by the use of Black Scholes Merton (BSM model is based on the assumption that asset prices have a lognormal distribution. In spite of the use of these models on a large scale, both by practioners and academics, the assumption of lognormality is rejected by the history of returns. The objective of this article is to present the methods that developed after the Black Scholes Merton environment and deals with the option pricing model adjustment to the empirical properties of asset returns. The main models that appeared after BSM allowed for special changes of the returns that materialized in jump-diffusion and stochastic volatility processes. The article presents the foundations of risk neutral options evaluation and the empirical evidence that fed the amendment of the lognormal assumption in the first part and shows the evaluation procedure under the assumption of stock prices following the jump-diffusion process and the stochastic volatility process.

  19. Flammable gas/slurry growth unreviewed safety question:justification for continued operation for the tank farms at the Hanford site

    Energy Technology Data Exchange (ETDEWEB)

    Leach, C.E., Westinghouse Hanford

    1996-07-31

    This Justification for Continued Operation (JCO) provides a basis for continued operation in 176 high level waste tanks, double contained receiver tanks (DCRTs), catch tanks, 244-AR Vault, 242-S and 242-T Evaporators and inactive miscellaneous underground storage tanks (IMUSTs) relative to flammable gas hazards. Required controls are specified.

  20. Measurement for the Flammability Point of Mg and Mg Alloy%镁及镁合金燃点的测试

    Institute of Scientific and Technical Information of China (English)

    陈萍; 张茂勋

    2001-01-01

    The three experimental sketches were made to measure the flammability point according to the physical and chemical characteristics of Mg and Mg alloy by the conventional methods of measuring the flammable solid mate rial's flammability point. Moreover, the results were analyzed. It was prelimina rily defined the possible temperature region of the Mg and Mg alloy's flammability point exists under certain grain size and temperature raising condition, so do the influence of the grain size and temperature raising condition on the flamm ability point.%根据镁及镁合金的物理、化学特性,借鉴常规可燃固体材料燃点的测试方法,设计了三种试 验方案,并对其结果进行处理分析。初步确定了在一定粒度和升温条件下镁及镁合金燃点可 能存在的温度区间以及粒度和升温条件对其燃点的影响。

  1. Inhibited flammability and surface inactivation of wood irradiated by low energy hydrogen ion showers (LEHIS)

    Energy Technology Data Exchange (ETDEWEB)

    Blantocas, Gene Q. [Plasma Physics Laboratory, National Institute of Physics, College of Science, University of the Philippines, Diliman, Quezon City 1101 (Philippines) and Physical Science Department, West Visayas State University, La Paz, Iloilo City 5000 (Philippines)]. E-mail: gqblantocas@yahoo.com; Mateum, Philip Edward R. [College of Architecture, University of the Philippines, Diliman, Quezon City 1101 (Philippines); Orille, Ross William M. [College of Architecture, University of the Philippines, Diliman, Quezon City 1101 (Philippines); Ramos, Rafael Julius U. [College of Architecture, University of the Philippines, Diliman, Quezon City 1101 (Philippines); Monasterial, Jonathan Lee C. [Plasma Physics Laboratory, National Institute of Physics, College of Science, University of the Philippines, Diliman, Quezon City 1101 (Philippines); Ramos, Henry J. [Plasma Physics Laboratory, National Institute of Physics, College of Science, University of the Philippines, Diliman, Quezon City 1101 (Philippines); Bo-ot, Luis Ma.T. [Plasma Physics Laboratory, National Institute of Physics, College of Science, University of the Philippines, Diliman, Quezon City 1101 (Philippines); Archilife Environ-Control Research Center, Department of Architecture, National Cheng Kung University, Tainan 701, Taiwan (China)

    2007-06-15

    Changes on the properties of wood irradiated by low energy hydrogen ion showers (LEHIS) were examined. The experimental facility employed was an in-house constructed, compact gas discharge ion source with beam energies maintained approximately in the 1keV range fixed at 1mA discharge current, 3mTorr gas filling pressure. Wood specimens used were of species endemic in the Philippines namely Shorea sp., Shorea polysperma and Cocos nucifera. Results showed the processed samples manifested characteristics of inhibited flammability, and became relatively hydrophobic after the treatment. In the fire resistance test, it was also observed during initial flaming that the processed surfaces accumulated less soot attesting to a much lower smoldering rate, i.e. lesser combustibility. To assess the increase in fire endurance time for the processed wood against the control substrates, a non-directional, two-tailed t-test was utilized. Significant at the 0.05 level, the t-statistic measured 9.164 as opposed to only 4.303 in its corresponding critical value at two degrees of freedom. Hence, the treatment appeared to show strong statistical evidence of being effective in enhancing fire resistance. The processed specimens also exhibited moisture absorptive inhibition time of more than 10min versus an average absorption period of just 8s for the unprocessed samples. Spectroscopy using a cast steel mass analyzer indicated a predominance of H{sup +} with faint signals of H{sub 2}{sup +} in the ion showers. It is hypothesized that the monatomic ion plays an essential participatory role in the surface modification process. Data from an earlier work using Narra wood (Pterocarpus indicus) [G.Q. Blantocas, H.J. Ramos, M. Wada, Jpn. J. Appl. Phys. 45 (2006) 8498] was extended in the current study to substantiate this hypothesis. The data is now presented as current density ratio H{sup +}/H{sub 2}{sup +} versus the change rate constant K of the wetting model equation. It is shown that wood

  2. Inhibited flammability and surface inactivation of wood irradiated by low energy hydrogen ion showers (LEHIS)

    Science.gov (United States)

    Blantocas, Gene Q.; Mateum, Philip Edward R.; Orille, Ross William M.; Ramos, Rafael Julius U.; Monasterial, Jonathan Lee C.; Ramos, Henry J.; Bo-ot, Luis Ma. T.

    2007-06-01

    Changes on the properties of wood irradiated by low energy hydrogen ion showers (LEHIS) were examined. The experimental facility employed was an in-house constructed, compact gas discharge ion source with beam energies maintained approximately in the 1 keV range fixed at 1 mA discharge current, 3 mTorr gas filling pressure. Wood specimens used were of species endemic in the Philippines namely Shorea sp., Shorea polysperma and Cocos nucifera. Results showed the processed samples manifested characteristics of inhibited flammability, and became relatively hydrophobic after the treatment. In the fire resistance test, it was also observed during initial flaming that the processed surfaces accumulated less soot attesting to a much lower smoldering rate, i.e. lesser combustibility. To assess the increase in fire endurance time for the processed wood against the control substrates, a non-directional, two-tailed t-test was utilized. Significant at the 0.05 level, the t-statistic measured 9.164 as opposed to only 4.303 in its corresponding critical value at two degrees of freedom. Hence, the treatment appeared to show strong statistical evidence of being effective in enhancing fire resistance. The processed specimens also exhibited moisture absorptive inhibition time of more than 10 min versus an average absorption period of just 8 s for the unprocessed samples. Spectroscopy using a cast steel mass analyzer indicated a predominance of H+ with faint signals of H2+in the ion showers. It is hypothesized that the monatomic ion plays an essential participatory role in the surface modification process. Data from an earlier work using Narra wood (Pterocarpus indicus) [G.Q. Blantocas, H.J. Ramos, M. Wada, Jpn. J. Appl. Phys. 45 (2006) 8498] was extended in the current study to substantiate this hypothesis. The data is now presented as current density ratio H+ /H2+versus the change rate constant K of the wetting model equation. It is shown that wood affinity to water decreased as the

  3. Peroxide induced volatile and non-volatile switching behavior in ZnO-based electrochemical metallization memory cell

    Science.gov (United States)

    Mangasa Simanjuntak, Firman; Chandrasekaran, Sridhar; Pattanayak, Bhaskar; Lin, Chun-Chieh; Tseng, Tseung-Yuen

    2017-09-01

    We explore the use of cubic-zinc peroxide (ZnO2) as a switching material for electrochemical metallization memory (ECM) cell. The ZnO2 was synthesized with a simple peroxide surface treatment. Devices made without surface treatment exhibits a high leakage current due to the self-doped nature of the hexagonal-ZnO material. Thus, its switching behavior can only be observed when a very high current compliance is employed. The synthetic ZnO2 layer provides a sufficient resistivity to the Cu/ZnO2/ZnO/ITO devices. The high resistivity of ZnO2 encourages the formation of a conducting bridge to activate the switching behavior at a lower operation current. Volatile and non-volatile switching behaviors with sufficient endurance and an adequate memory window are observed in the surface-treated devices. The room temperature retention of more than 104 s confirms the non-volatility behavior of the devices. In addition, our proposed device structure is able to work at a lower operation current among other reported ZnO-based ECM cells.

  4. Resource Prospector: An Update on the Lunar Volatiles Prospecting and ISRU Demonstration Mission

    Science.gov (United States)

    Colaprete, A.; Elphic, R.; Andrews, D.; Trimble, J.; Bluethmann, B.; Quinn, J.; Chavers, G.

    2017-01-01

    Over the last two decades a wealth of new observations of the moon have demonstrated a lunar water system dramatically more complex and rich than was deduced following the Apollo era. Lunar water, and other volatiles, have the potential to be a valuable or enabling resource for future exploration. The NASA Human Exploration and Operations Mission Directorate (HEOMD) have selected a lunar volatiles prospecting mission for a concept study and potential flight in CY2021. The mission includes a rover-borne payload that (1) can locate surface and near-subsurface volatiles, (2) excavate and analyze samples of the volatile- bearing regolith, and (3) demonstrate the form, extractability and usefulness of the materials.

  5. Potential interaction between the volatile and non-volatile fractions on the in vitro antimicrobial activity of three South African Pelargonium (Geraniaceae) species.

    Science.gov (United States)

    Lalli, Jacqueline Y; Viljoen, Alvaro M; Van Vuuren, Sandy F

    2010-09-01

    Previous studies have reported promising antimicrobial efficacy for the essential oils and solvent extracts of several indigenous Pelargonium species. This study aimed to determine if any pharmacological interaction (e.g. synergism or antagonism) exists between the volatile and non-volatile components when the different fractions were investigated. The antimicrobial activity of the following fractions were tested; the essential oil prepared by hydrodistillation (EO), non-volatile fraction (NV), prepared by extraction of plant material remaining in the distilling apparatus (having no or negligible volatile constituents) and solvent extracts prepared from fresh (FC) and dried (DC) plant material containing both volatile and non-volatile constituents. Pelargonium quercifolium oil was dominated by p-cymene (42.1%) and viridiflorol (16.9%), while P. graveolens and P. tomentosum oil had high levels of isomenthone (84.0 and 58.8%, respectively). Menthone was noted as a major constituent in the P. tomentosum EO sample. It was evident from the results that the presence of volatile constituents in the three species; P. graveolens, P. quercifolium and P. tomentosum is generally not a pre-requisite for antimicrobial activity. The most significant variations of antimicrobial activity were noted for P. tomentosum where poorer activity was noted for the FC and EO fractions against Bacillus cereus and Candida albicans. Studies on Staphylococcus aureus, however, showed the converse, where best activity was noted for the FC fraction (3.0 mg/mL). For P. quercifolium, the DC fraction indicated a notable increase in anti-staphylococcal activity (2.0 mg/mL) when compared with the FC (8.0 mg/mL) and EO (16.0 mg/mL) fractions. For P. tomentosum, the FC fraction indicated much lower antimicrobial activity (against both B. cereus and C. albicans) when compared with all other fractions, suggesting that the essential oils may impact negatively on the antimicrobial activity when tested against

  6. Belief biases and volatility of assets

    Science.gov (United States)

    Lei-Sun, Wen-Zou, Hui

    2014-10-01

    Based on an overlapping generation model, this paper introduces the noise traders with belief biases and rational traders. With an equilibrium analysis, this paper examines the volatility of risky asset. The results show that the belief biases, the probability of economy state, and the domain capability are all the factors that have effects on the volatility of the market.

  7. Explaining output volatility: The case of taxation

    DEFF Research Database (Denmark)

    Posch, Olaf

    empirical link between e ective tax rates and output volatility, with some evidence of a cointegrating relationship. In accordance with theory, taxes on labor income and corporate income empirically are found to be negatively related to volatility of macro aggregates whereas the capital tax ratio has...

  8. Effects of Idiosyncratic Volatility in Asset Pricing

    Directory of Open Access Journals (Sweden)

    André Luís Leite

    2016-04-01

    Full Text Available This paper aims to evaluate the effects of the aggregate market volatility components - average volatility and average correlation - on the pricing of portfolios sorted by idiosyncratic volatility, using Brazilian data. The study investigates whether portfolios with high and low idiosyncratic volatility - in relation to the Fama and French model (1996 - have different exposures to innovations in average market volatility, and consequently, different expectations for return. The results are in line with those found for US data, although they portray the Brazilian reality. Decomposition of volatility allows the average volatility component, without the disturbance generated by the average correlation component, to better price the effects of a worsening or an improvement in the investment environment. This result is also identical to that found for US data. Average variance should thus command a risk premium. For US data, this premium is negative. According to Chen and Petkova (2012, the main reason for this negative sign is the high level of investment in research and development recorded by companies with high idiosyncratic volatility. As in Brazil this type of investment is significantly lower than in the US, it was expected that a result with the opposite sign would be found, which is in fact what occurred.

  9. Some recent developments in stochastic volatility modelling

    DEFF Research Database (Denmark)

    Barndorff-Nielsen, Ole Eiler; Nicolato, Elisa; Shephard, N.

    2002-01-01

    This paper reviews and puts in context some of our recent work on stochastic volatility (SV) modelling for financial economics. Here our main focus is on: (i) the relationship between subordination and SV, (ii) OU based volatility models, (iii) exact option pricing, (iv) realized power variation...

  10. Volatility Determination in an Ambit Process Setting

    DEFF Research Database (Denmark)

    Barndorff-Nielsen, Ole; Graversen, Svend-Erik

    The probability limit behaviour of normalised quadratic variation is studied for a simple tempo-spatial ambit process, with particular regard to the question of volatility memorylessness.......The probability limit behaviour of normalised quadratic variation is studied for a simple tempo-spatial ambit process, with particular regard to the question of volatility memorylessness....

  11. Analyzing volatile compounds in dairy products

    Science.gov (United States)

    Volatile compounds give the first indication of the flavor in a dairy product. Volatiles are isolated from the sample matrix and then analyzed by chromatography, sensory methods, or an electronic nose. Isolation may be performed by solvent extraction or headspace analysis, and gas chromatography i...

  12. Stock market volatility and macroeconomic uncertainty

    NARCIS (Netherlands)

    Arnold, I.J.M.; Vrugt, E.B.

    2006-01-01

    This paper provides empirical evidence on the link between stock market volatility and macroeconomic uncertainty. We show that US stock market volatility is significantly related to the dispersion in economic forecasts from SPF survey participants over the period from 1969 to 1996. This link is much

  13. Stock market volatility and macroeconomic uncertainty

    NARCIS (Netherlands)

    Arnold, I.J.M.; Vrugt, E.B.

    2006-01-01

    This paper provides empirical evidence on the link between stock market volatility and macroeconomic uncertainty. We show that US stock market volatility is significantly related to the dispersion in economic forecasts from SPF survey participants over the period from 1969 to 1996. This link is much

  14. Fundamental uncertainty and stock market volatility

    NARCIS (Netherlands)

    Arnold, I.J.M.; Vrugt, E.B.

    2008-01-01

    We provide empirical evidence on the link between stock market volatility and macroeconomic uncertainty. We show that US stock market volatility is significantly related to the dispersion in economic forecasts from participants in the Survey of Professional Forecasters over the period 1969 to 1996.

  15. Price volatility in wind dominant electricity markets

    DEFF Research Database (Denmark)

    Farashbashi-Astaneh, Seyed-Mostafa; Chen, Zhe

    2013-01-01

    High penetration of intermittent renewable energy sources causes price volatility in future electricity markets. This is specially the case in European countries that plan high penetration levels. This highlights the necessity for revising market regulations and mechanisms in accordance to genera......High penetration of intermittent renewable energy sources causes price volatility in future electricity markets. This is specially the case in European countries that plan high penetration levels. This highlights the necessity for revising market regulations and mechanisms in accordance...... electricity markets. High price volatility is unappreciated because it imposes high financial risk levels to both electricity consumers and producers. Additionally high price variations impede tracking price signals by consumers in future smart grid and jeopardize implementation of demand response concepts....... The main contribution of this paper is to quantify volatility patterns of electricity price, as penetration level of wind power increases. Results explain a direct relationship between wind penetration and electricity price volatility in a quantitative manner....

  16. Volatility smile as relativistic effect

    Science.gov (United States)

    Kakushadze, Zura

    2017-06-01

    We give an explicit formula for the probability distribution based on a relativistic extension of Brownian motion. The distribution (1) is properly normalized and (2) obeys the tower law (semigroup property), so we can construct martingales and self-financing hedging strategies and price claims (options). This model is a 1-constant-parameter extension of the Black-Scholes-Merton model. The new parameter is the analog of the speed of light in Special Relativity. However, in the financial context there is no ;speed limit; and the new parameter has the meaning of a characteristic diffusion speed at which relativistic effects become important and lead to a much softer asymptotic behavior, i.e., fat tails, giving rise to volatility smiles. We argue that a nonlocal stochastic description of such (Lévy) processes is inadequate and discuss a local description from physics. The presentation is intended to be pedagogical.

  17. Clustered volatility in multiagent dynamics

    CERN Document Server

    Youssefmir, M; Youssefmir, Michael; Huberman, Bernardo

    1995-01-01

    Large distributed multiagent systems are characterized by vast numbers of agents trying to gain access to limited resources in an unpredictable environment. Agents in these system continuously switch strategies in order to opportunistically find improvements in their utilities. We have analyzed the fluctuations around equilibrium that arise from strategy switching and discovered the existence of a new phenomenon. It consists of the appearance of sudden bursts of activity that punctuate the fixed point, and is due to an effective random walk consistent with overall stability. This clustered volatility is followed by relaxation to the fixed point but with different strategy mixes from the previous one. This phenomenon is quite general for systems in which agents explore strategies in search of local improvements.

  18. Forecasting Exchange Rate Volatility in the Presence of Jumps

    DEFF Research Database (Denmark)

    Busch, Thomas; Christensen, Bent Jesper; Nielsen, Morten Ørregaard

    of exchange rate futures options, allowingcalculation of option implied volatility. We find that implied volatility is an informationallyefficient but biased forecast of future realized exchange rate volatility. Furthermore,we show that log-normality is an even better distributional approximation...... for impliedvolatility than for realized volatility in this market. Finally, we show that the jump componentof future realized exchange rate volatility is to some extent predictable, and thatoption implied volatility is the dominant forecast of the future jump component....

  19. Effects of Lewis-acid polymer on the electrochemical properties of alkylphosphate-based non-flammable gel electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Lalia, Boor Singh; Yoshimoto, Nobuko; Egashira, Minato; Morita, Masayuki [Department of Applied Chemistry, Graduate School of Science and Engineering, Yamaguchi University, 2-16-1 Tokiwadai, Ube 755-8611 (Japan)

    2009-10-20

    Non-flammable polymer gel electrolytes (NPGE) consisting of 1.0 mol dm{sup -3} (=M) LiBF{sub 4}/EC + DEC + TEP (55:25:20 volume ratio) + PVdF-HFP (EC: ethylene carbonate, DEC: diethyl carbonate, TEP: triethylphosphate, PVdF-HFP: poly(vinyledenefluoride-co-hexafluoropropylene)) have been developed for rechargeable lithium batteries. The effects of addition of Lewis-acid polymer (LAP) with different mole ratio in NPGE have been studied. The addition of LAP improved physico-chemical properties of NPGE, viz ionic conductivity and lithium ion transport number, as well as mechanical and thermal properties. The ionic conductivity of the gel electrolyte containing LAP reached that of the base solution electrolyte (1.0 M LiBF{sub 4}/EC + DEC + TEP (55:25:20)) along with better mechanical properties. Interfacial resistance at Li-metal electrode/NPGE was also improved by introducing LAP in the gel. (author)

  20. Effects of Lewis-acid polymer on the electrochemical properties of alkylphosphate-based non-flammable gel electrolyte

    Science.gov (United States)

    Lalia, Boor Singh; Yoshimoto, Nobuko; Egashira, Minato; Morita, Masayuki

    Non-flammable polymer gel electrolytes (NPGE) consisting of 1.0 mol dm -3 (=M) LiBF 4/EC + DEC + TEP (55:25:20 volume ratio) + PVdF-HFP (EC: ethylene carbonate, DEC: diethyl carbonate, TEP: triethylphosphate, PVdF-HFP: poly(vinyledenefluoride-co-hexafluoropropylene)) have been developed for rechargeable lithium batteries. The effects of addition of Lewis-acid polymer (LAP) with different mole ratio in NPGE have been studied. The addition of LAP improved physico-chemical properties of NPGE, viz ionic conductivity and lithium ion transport number, as well as mechanical and thermal properties. The ionic conductivity of the gel electrolyte containing LAP reached that of the base solution electrolyte (1.0 M LiBF 4/EC + DEC + TEP (55:25:20)) along with better mechanical properties. Interfacial resistance at Li-metal electrode/NPGE was also improved by introducing LAP in the gel.

  1. Challenges and methodology for safety analysis of a high-level waste tank with large periodic releases of flammable gas

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, J.N.; Pasamehmetoglu, K.O.; White, J.R. [Los Alamos National Lab., NM (United States); Stewart, C.W. [Pacific Northwest Lab., Richland, WA (United States)

    1994-07-01

    Tank 241-SY-101, located at the Department of Energy Hanford Site, has periodically released up to 10,000 ft{sup 3} of flammable gas. This release has been one of the highest-priority DOE operational safety problems. The gases include hydrogen and ammonia (fuels) and nitrous oxide (oxidizer). There have been many opinions regarding the controlling mechanisms for these releases, but demonstrating an adequate understanding of the problem, selecting a mitigation methodology, and preparing the safety analysis have presented numerous new challenges. The mitigation method selected for the tank was to install a pump that would mix the tank contents and eliminate the sludge layer believed to be responsible for the gas retention and periodic releases. This report will describe the principal analysis methodologies used to prepare the safety assessment for the installation and operation of the pump, and because this activity has been completed, it will describe the results of pump operation.

  2. Investigation of the Extinguishing Features for Liquid Fuels and Organic Flammable Liquids Atomized by a Water Flow

    Directory of Open Access Journals (Sweden)

    Voytkov Ivan V.

    2016-01-01

    Full Text Available The processes of heat and mass transfer were investigated experimentally while moving and evaporating the atomized water flow in high-temperature combustion products of typical liquid fuels and organic flammable liquids: gasoline, kerosene, acetone, crude oil, industrial alcohol. We determined typical periods of liquid extinguishing by an atomized water flow of various dispersability. Data of the discharge of extinguishing medium corresponding to various parameters of atomization and duration of using the atomization devices was presented. It is shown that Um≈3.5 m/s is a minimal outflow velocity of droplets during moving while passing the distance of 1m in the high-temperature gas medium to stop the combustion of organic liquids.

  3. Fabrication of polystyrene/agave particle biocomposites using compression molding technique: evaluation of flammability, biodegradability, mechanical and thermal behaviour

    Indian Academy of Sciences (India)

    A S Singha; Raj K Rana

    2013-12-01

    Polystyrene (PS) composites reinforced with ungrafted and acrylonitrile (AN) grafted agave particles (AgP) have been prepared with 10–30% particle content by weight using compression molding technique. The composite specimens thus prepared were subjected to the evaluation of mechanical, chemical, flammability and biodegradability properties. PS composites with 20% particle loading exhibited optimum mechanical properties. AN grafted AgP/PS composites exhibited higher mechanical strength as compared to ungrafted AgP/PS composites. Further AN grafted AgP/PS composites exhibited better thermal properties and biodegradability as compared to PS matrix. Addition of fire retardant fillers such as magnesium hydroxide Mg(OH)2 and zinc borate lowered burning rate of PS composites considerably. Scanning electron microscopy (SEM) of tensile fracture surfaces of AN grafted AgP/PS composites showed better particle/matrix adhesion.

  4. Effect of Particle Size of Additives on the Flammability and Mechanical Properties of Intumescent Flame Retarded Polypropylene Compounds

    Directory of Open Access Journals (Sweden)

    Katalin Bocz

    2015-01-01

    Full Text Available The effect of particle size reduction of the components of a common intumescent flame retardant system, consisting of pentaerythritol (PER and ammonium polyphosphate (APP in a weight ratio of 1 to 2, was investigated on the flammability and mechanical performance of flame retarded polypropylene (PP compounds. Additives of reduced particle size were obtained by ball milling. In the case of PER, the significant reduction of particle size resulted in inferior flame retardant and mechanical performance, while the systems containing milled APP noticeably outperformed the reference intumescent system containing as-received additives. The beneficial effect of the particle size reduction of APP is explained by the better distribution of the particles in the polymer matrix and by the modified degradation mechanism which results in the formation of an effectively protecting carbonaceous foam accompanied with improved mechanical resistance. Nevertheless, 10% higher tensile strength was measured for the flame retarded PP compound when as-received APP was substituted by milled APP.

  5. Baseline intrinsic flammability of Earth’s ecosystems estimated from paleoatmospheric oxygen over the past 350 million years

    Science.gov (United States)

    Belcher, Claire M.; Yearsley, Jonathan M.; Hadden, Rory M.; McElwain, Jennifer C.; Rein, Guillermo

    2010-01-01

    Atmospheric oxygen (O2) is estimated to have varied greatly throughout Earth’s history and has been capable of influencing wildfire activity wherever fuel and ignition sources were present. Fires consume huge quantities of biomass in all ecosystems and play an important role in biogeochemical cycles. This means that understanding the influence of O2 on past fire activity has far-reaching consequences for the evolution of life and Earth’s biodiversity over geological timescales. We have used a strong electrical ignition source to ignite smoldering fires, and we measured their self-sustaining propagation in atmospheres of different oxygen concentrations. These data have been used to build a model that we use to estimate the baseline intrinsic flammability of Earth’s ecosystems according to variations in O2 over the past 350 million years (Ma). Our aim is to highlight times in Earth’s history when fire has been capable of influencing the Earth system. We reveal that fire activity would be greatly suppressed below 18.5% O2, entirely switched off below 16% O2, and rapidly enhanced between 19–22% O2. We show that fire activity and, therefore, its influence on the Earth system would have been high during the Carboniferous (350–300 Ma) and Cretaceous (145–65 Ma) periods; intermediate in the Permian (299–251 Ma), Late Triassic (285–201 Ma), and Jurassic (201–145 Ma) periods; and surprisingly low to lacking in the Early–Middle Triassic period between 250–240 Ma. These baseline variations in Earth’s flammability must be factored into our understanding of past vegetation, biodiversity, evolution, and biogeochemical cycles. PMID:21149686

  6. Evaluation of mitigation strategies in Facility Group 1 double-shell flammable-gas tanks at the Hanford Site

    Energy Technology Data Exchange (ETDEWEB)

    Unal, C.; Sadasivan, P.; Kubic, W.L.; White, J.R.

    1997-11-01

    Radioactive nuclear waste at the Hanford Site is stored in underground waste storage tanks at the site. The tanks fall into two main categories: single-shell tanks (SSTs) and double-shell tanks (DSTs). There are a total of 149 SSTs and 28 DSTs. The wastes stored in the tanks are chemically complex. They basically involve various sodium salts (mainly nitrite, nitrate, carbonates, aluminates, and hydroxides), organic compounds, heavy metals, and various radionuclides, including cesium, strontium, plutonium, and uranium. The waste is known to generate flammable gas (FG) [hydrogen, ammonia, nitrous oxide, hydrocarbons] by complex chemical reactions. The process of gas generation, retention, and release is transient. Some tanks reach a quasi-steady stage where gas generation is balanced by the release rate. Other tanks show continuous cycles of retention followed by episodic release. There currently are 25 tanks on the Flammable Gas Watch List (FGWL). The objective of this report is to evaluate possible mitigation strategies to eliminate the FG hazard. The evaluation is an engineering study of mitigation concepts for FG generation, retention, and release behavior in Tanks SY-101, AN-103, AN 104, An-105, and Aw-101. Where possible, limited quantification of the effects of mitigation strategies on the FG hazard also is considered. The results obtained from quantification efforts discussed in this report should be considered as best-estimate values. Results and conclusions of this work are intended to help in establishing methodologies in the contractor`s controls selection analysis to develop necessary safety controls for closing the FG unreviewed safety question. The general performance requirements of any mitigation scheme are discussed first.

  7. Zinc and volatile element loss during planetary magma ocean phases

    Science.gov (United States)

    Dhaliwal, Jasmeet K.; Day, James M. D.; Moynier, Frédéric

    2016-10-01

    Zinc is a moderately volatile element and a key tracer of volatile depletion on planetary bodies due to lack of significant isotopic fractionation under high-temperature processes. Terrestrial basalts have δ66Zn values similar to some chondrites (+ 0.15 to 0.3‰ where [{66Zn/64Znsample/66Zn/64ZnJMC-Lyon-1} × 1000]) and elevated Zn concentrations (100 ppm). Lunar mare basalts yield a mean δ66Zn value of +1.4 ± 0.5‰ and have low Zn concentrations (~2 ppm). Late-stage lunar magmatic products, such as ferroan anorthosite, Mg-suite and Alkali suite rocks exhibit heavier δ66Zn values (+3 to +6‰). The heavy δ66Zn lunar signature is thought to reflect evaporative loss and fractionation of zinc, either during a giant impact or in a magma ocean phase.We explore conditions of volatile element loss within a lunar magma ocean (LMO) using models of Zn isotopic fractionation that are widely applicable to planetary magma oceans. For the Moon, our objective was to identify conditions that would yield a δ66Zn signature of ~ +1.4‰ within the mantle, assuming a terrestrial mantle zinc starting composition.We examine two cases of zinc evaporative fractionation: (1) lunar surface zinc fractionation that was completed prior to LMO crystallization and (2) lunar surface zinc fractionation that was concurrent with LMO crystallization. The first case resulted in a homogeneous lunar mantle and the second case yielded a stratified lunar mantle, with the greatest zinc isotopic enrichment in late-stage crystallization products. This latter case reproduces the distribution of zinc isotope compositions in lunar materials quite well.We find that hydrodynamic escape was not a dominant process in losing Zn, but that erosion of a nascent lunar atmosphere, or separation of condensates into a proto-lunar crust are possible. While lunar volatile depletion is still possible as a consequence of the giant impact, this process cannot reproduce the variable δ66Zn found in the Moon. Outgassing

  8. Effect of different drying techniques on bioactive components, fatty acid composition, and volatile profile of robusta coffee beans.

    Science.gov (United States)

    Dong, Wenjiang; Hu, Rongsuo; Chu, Zhong; Zhao, Jianping; Tan, Lehe

    2017-11-01

    This study investigated the effect of different drying techniques, namely, room-temperature drying (RTD), solar drying (SD), heat-pump drying (HPD), hot-air drying (HAD), and freeze drying (FD), on bioactive components, fatty acid composition, and the volatile compound profile of robusta coffee beans. The data showed that FD was an effective method to preserve fat, organic acids, and monounsaturated fatty acids. In contrast, HAD was ideal for retaining polyunsaturated fatty acids and amino acids. Sixty-two volatile compounds were identified in the differently dried coffee beans, representing 90% of the volatile compounds. HPD of the coffee beans produced the largest number of volatiles, whereas FD resulted in the highest volatile content. A principal component analysis demonstrated a close relationship between the HPD, SD, and RTD methods whereas the FD and HAD methods were significantly different. Overall, the results provide a basis for potential application to other similar thermal sensitive materials. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Tracing recycled volatiles in a heterogeneous mantle with boron isotopes

    Science.gov (United States)

    Walowski, Kristina; Kirstein, Linda; de Hoog, Cees-Jan; Elliot, Tim; Savov, Ivan; Devey, Colin

    2016-04-01

    Recycling of oceanic lithosphere drives the chemical evolution of the Earth's mantle supplying both solids and volatiles to the Earth's interior. Yet, how subducted material influences mantle composition remains unclear. A perfect tracer for slab recycling should be only fractionated at the Earth's surface, have a strong influence on mantle compositions but be resistant to perturbations en route back to the surface. Current understanding suggests that boron concentrations linked to B isotope determinations fulfil all these requirements and should be an excellent tracer of heterogeneity in the deep mantle. Here, we present the trace element, volatile and the B isotope composition of basaltic glasses and melt inclusions in olivine from distinct end-member ocean island basalts (OIB) to track the fate of recycled lithosphere and ultimately document how recycling contributes to mantle heterogeneity. The chosen samples represent the different end member OIB compositions and include: EMI (Pitcairn), EMII (MacDonald), HIMU (St. Helena), and FOZO (Cape Verde & Reunion). The data is derived from both submarine and subaerial deposits, with B isotope determination of both basaltic glass and melt inclusions from each locality. Preliminary results suggest OIB have B isotopic compositions that overlap the MORB array (-7.5‰±0.7; Marschall et al., 2015) but extend to both lighter and heavier values. These results suggest that B isotopes will be useful for resolving mantle source heterogeneity at different ocean islands and contribute to our understanding of the volatile budget of the deep mantle.

  10. Flower volatiles, crop varieties and bee responses.

    Directory of Open Access Journals (Sweden)

    Björn K Klatt

    Full Text Available Pollination contributes to an estimated one third of global food production, through both the improvement of the yield and the quality of crops. Volatile compounds emitted by crop flowers mediate plant-pollinator interactions, but differences between crop varieties are still little explored. We investigated whether the visitation of crop flowers is determined by variety-specific flower volatiles using strawberry varieties (Fragaria x ananassa Duchesne and how this affects the pollination services of the wild bee Osmia bicornis L. Flower volatile compounds of three strawberry varieties were measured via headspace collection. Gas chromatography showed that the three strawberry varieties produced the same volatile compounds but with quantitative differences of the total amount of volatiles and between distinct compounds. Electroantennographic recordings showed that inexperienced females of Osmia bicornis had higher antennal responses to all volatile compounds than to controls of air and paraffin oil, however responses differed between compounds. The variety Sonata was found to emit a total higher level of volatiles and also higher levels of most of the compounds that evoked antennal responses compared with the other varieties Honeoye and Darselect. Sonata also received more flower visits from Osmia bicornis females under field conditions, compared with Honeoye. Our results suggest that differences in the emission of flower volatile compounds among strawberry varieties mediate their attractiveness to females of Osmia bicornis. Since quality and quantity of marketable fruits depend on optimal pollination, a better understanding of the role of flower volatiles in crop production is required and should be considered more closely in crop-variety breeding.

  11. Volatility Forecast in Crises and Expansions

    Directory of Open Access Journals (Sweden)

    Sergii Pypko

    2015-08-01

    Full Text Available We build a discrete-time non-linear model for volatility forecasting purposes. This model belongs to the class of threshold-autoregressive models, where changes in regimes are governed by past returns. The ability to capture changes in volatility regimes and using more accurate volatility measures allow outperforming other benchmark models, such as linear heterogeneous autoregressive model and GARCH specifications. Finally, we show how to derive closed-form expression for multiple-step-ahead forecasting by exploiting information about the conditional distribution of returns.

  12. Modelling of volatility in monetary transmission mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Dobešová, Anna; Klepáč, Václav; Kolman, Pavel [Department of Statistics and Operation Analysis, Faculty of Business and Economics, Mendel University in Brno, Zemědělská 1, 61300, Brno (Czech Republic); Bednářová, Petra [Institute of Technology and Business, Okružní 517/10, 370 01, České Budějovice (Czech Republic)

    2015-03-10

    The aim of this paper is to compare different approaches to modeling of volatility in monetary transmission mechanism. For this purpose we built time-varying parameter VAR (TVP-VAR) model with stochastic volatility and VAR-DCC-GARCH model with conditional variance. The data from three European countries are included in the analysis: the Czech Republic, Germany and Slovakia. Results show that VAR-DCC-GARCH system captures higher volatility of observed variables but main trends and detected breaks are generally identical in both approaches.

  13. Securing non-volatile memory regions

    Science.gov (United States)

    Faraboschi, Paolo; Ranganathan, Parthasarathy; Muralimanohar, Naveen

    2013-08-20

    Methods, apparatus and articles of manufacture to secure non-volatile memory regions are disclosed. An example method disclosed herein comprises associating a first key pair and a second key pair different than the first key pair with a process, using the first key pair to secure a first region of a non-volatile memory for the process, and using the second key pair to secure a second region of the non-volatile memory for the same process, the second region being different than the first region.

  14. Hygroscopicity and ammonia volatilization losses from nitrogen sources in coated urea

    Directory of Open Access Journals (Sweden)

    Letícia de Abreu Faria

    2014-06-01

    Full Text Available Hygroscopic fertilizers tend to absorb moisture from the air and may have undesirable characteristics such as moistness, clumping and lower fluidity, hampering the application. The increasing use of urea is due to its numerous advantages, although this nitrogen (N source is highly susceptible to volatilization losses, particularly when applied to the soil surface of management systems with conservation of crop residues. The volatilization losses can be minimized by slow or controlled-release fertilizers, with controlled water solubility of the urea-coating materials; and by stabilized fertilizers, which prolong the period during which N remains in the amide or ammonia forms by urease inhibitors. This study evaluated the hygroscopicity of and ammonia volatilization from urea coated with boric acid and copper sulfate or with sulfur. The hygroscopicity of the sources was evaluated over time after exposure to five levels of relative humidity (RH and volatilization evaluated after application to the soil surface covered with sugarcane trash. Ammonium nitrate has a low potential for volatilization losses, but is highly hygroscopic. Although coating with boric acid and copper sulfate or elemental sulfur reduced the critical humidity level of urea, the delay in the volatilization process is a potential positive factor.

  15. The sampling apparatus of volatile organic compounds for wood composites

    Institute of Scientific and Technical Information of China (English)

    SHENJun; ZHAOLin-bo; LIUYu

    2005-01-01

    Terpenes, aldehydes, ketones, benzene, and toluene are the important volatile organic compounds (VOCs) emitted from wood composites. A sampling apparatus of VOCs for wood composites was designed and manufactured by Northeast Forestry University in China.The concentration of VOCs derived from wood based materials, such as flooring, panel wall, finishing, and furniture can be sampled in a small stainless steel chambers. A protocol is also developed in this study to sample and measure the new and representative specimens. Preliminary research showed that the properties of the equipment have good stability. The sort and the amount of different components can be detected from it. The apparatus is practicable.

  16. Review on Volatile Organic Compounds Emission from Wood Composites

    Institute of Scientific and Technical Information of China (English)

    LIU Yu; YU Yaoming; SHEN Jun; LIU Ming

    2006-01-01

    The problem of indoor air quality (IAQ) is mainly caused by the volatile organic compounds (VOC) emission from the wood-based composites. As a material for decoration, furniture manufacturing or building, wood-based composite is one of the sources of VOC emissions. Most of them are formaldehyde, terpene, ketone and benzene. The paper reviews on VOC emission of wood-based composites at home and abroad, including the source of the VOC, its impacts on IAQ, its emission during processing and using, the usual sampling and analyse methods of VOC in different conditions. Meanwhile, main problems existed in the past researches are summarized and some suggestions are put forward.

  17. Realized volatility and absolute return volatility: a comparison indicating market risk.

    Science.gov (United States)

    Zheng, Zeyu; Qiao, Zhi; Takaishi, Tetsuya; Stanley, H Eugene; Li, Baowen

    2014-01-01

    Measuring volatility in financial markets is a primary challenge in the theory and practice of risk management and is essential when developing investment strategies. Although the vast literature on the topic describes many different models, two nonparametric measurements have emerged and received wide use over the past decade: realized volatility and absolute return volatility. The former is strongly favored in the financial sector and the latter by econophysicists. We examine the memory and clustering features of these two methods and find that both enable strong predictions. We compare the two in detail and find that although realized volatility has a better short-term effect that allows predictions of near-future market behavior, absolute return volatility is easier to calculate and, as a risk indicator, has approximately the same sensitivity as realized volatility. Our detailed empirical analysis yields valuable guidelines for both researchers and market participants because it provides a significantly clearer comparison of the strengths and weaknesses of the two methods.

  18. Does Energy Consumption Volatility Affect Real GDP Volatility? An Empirical Analysis for the UK

    OpenAIRE

    Abdul Rashid; Ozge Kandemir Kocaaslan

    2013-01-01

    This paper empirically examines the relation between energy consumption volatility and unpredictable variations in real gross domestic product (GDP) in the UK. Estimating the Markov switching ARCH model we find a significant regime switching in the behavior of both energy consumption and GDP volatility. The results from the Markov regime-switching model show that the variability of energy consumption has a significant role to play in determining the behavior of GDP volatilities. Moreover, the...

  19. Lunar In-Situ Volatile Extraction Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A method of extracting volatile resources from the Lunar regolith is proposed to reduce the launch mass and cost of bringing such resources from the Earth to enable...

  20. Food commodity price volatility and food insecurity

    National Research Council Canada - National Science Library

    Alexander Sarris

    2013-01-01

      The paper first reviews several issues relevant to global food commodity market volatility as it pertains to food security, and food importing developing countries, and then discusses international...