WorldWideScience

Sample records for acid gas hazards

  1. Shale gas, a hazardous exploitation

    In march 2010 three authorizations to search for shale gases were delivered in France in the regions of Montelimar, Nant and Villeneuve-de-Berg. A general public outcry has led the government to freeze the projects till a complete assessment of the impact on the environment is made. The fears of the public are based on the feedback experience in the Usa where some underground waters were polluted. The source of pollution is twofold: first the additives used in the injected fluids (methanol as an anti-microbic agent, hydrochloric acid to dissolve natural cements or glycol ethylene as a deposit inhibitor) and secondly metal particles of copper, zinc or lead trapped in the clay layers and released by the injection of the fluids. It appears also that the injection of high pressure fluids near a crack can induce earth tremors by reactivating the crack. (A.C.)

  2. The real hazards of shale gas

    This bibliographical sheet presents a book which addresses the issue of shale gas. A first part describes the origin of this gaseous hydrocarbon, the composition of shale gas and its extraction, the technique of hydraulic fracturing, and the environmental risks. A second part addresses the economic, ecologic and political issues. The authors outline that all signs are there to prove the alarming hazards of shale gas. One of the authors outlines the necessity of an energy transition, far from fossil and nuclear energy, in order to guarantee a high level of protection of human health and of the environment

  3. Chemical hazards arising from shale gas extraction

    Daria Pakulska

    2015-02-01

    Full Text Available The development of the shale industry is gaining momentum and hence the analysis of chemical hazards to the environment and health of the local population is extremely timely and important. Chemical hazards are created during the exploitation of all minerals, but in the case of shale gas production, there is much more uncertainty as regards to the effects of new technologies application. American experience suggests the increasing risk of environmental contamination, mainly groundwater. The greatest concern is the incomplete knowledge of the composition of fluids used for fracturing shale rock and unpredictability of long-term effects of hydraulic fracturing for the environment and health of residents. High population density in the old continent causes the problem of chemical hazards which is much larger than in the USA. Despite the growing public discontent data on this subject are limited. First of all, there is no epidemiological studies to assess the relationship between risk factors, such as air and water pollution, and health effects in populations living in close proximity to gas wells. The aim of this article is to identify and discuss existing concepts on the sources of environmental contamination, an indication of the environment elements under pressure and potential health risks arising from shale gas extraction. Med Pr 2015;66(1:99–117

  4. Structural comparison of hazardous and non-hazardous coals based on gas sorption experiments

    Lakatos, J.; Toth, J. [Research Lab. for Mining Chemistry, Hungarian Academy of Sciences, Miskolc-Egyetemvaros (Hungary); Radnai-Gyoengyoes, Z. [Geopard Ltd., Pecs (Hungary); Bokanyi, L. [Miskolc Univ., Miskolc-Egyetemvaros (Hungary). Dept. of Process Engineering

    1997-12-31

    Comparison of carbon-dioxide and propane sorption at ambient temperature was used for characterising the difference of the structure of hazardous and non hazardous coals. However, hazardous coals were found more microporous or contain more closed pores than non hazardous ones, this difference couldn`t have been enlarged and attributed to one petrographic component by producing the density fractions. Gas sorption isobars (nitrogen, methane, ethane) are proposed to make a distinction between fine pore structure of coals. (orig.)

  5. Solid and hazardous waste management issues for gas processing facilities

    This paper reports on common solid and hazardous waste related concerns associated with gas processing which include proper management and storage of hazardous material and hazardous waste, proper handling of controlled non-hazardous material such as petroleum hydrocarbons, and assessment, remediation and control of special contaminants such as PCB and asbestos. The Federal state, and local regulations governing management of these materials continues to change, typically trending toward more stringent control of waste handling and disposal, and sometimes affecting waste materials that were previously disposed of as non-hazardous solid waste. More recent, regulatory changes affecting gas processing facilities include proper waste characterization and record keeping, underground tank removal and leak management, on-site waste disposal options and remedial alternatives for chemical spills, PCB contamination assessments for processing equipment and facilities and used oil management

  6. Gas migration from oil and gas fields and associated hazards

    The migration of gas from oil and gas formations to the surface is a problem that greatly affects those surface areas where human activity exists. Underground gas storage facilities and oil fields have demonstrated a long history of gas migration problems. Experience has shown that the migration of gas to the surface creates a serious potential risk of explosion, fires, noxious odors and potential emissions of carcinogenic chemicals. These risks must be seriously examined for all oil and gas operations located in urban areas. This paper presents the mechanics of gas migration, paths of migration and a review of a few of the risks that should be considered when operating a gas facility in an urban area. The gas can migrate in a continuous or discontinuous stream through porous, water-filled media to the surface. The primary force in this migration of gas is the difference between specific weights of gas and water

  7. Hazard assessments of double-shell flammable gas tanks

    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.

  8. Hazard assessments of double-shell flammable gas tanks

    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

  9. Chlorine Gas: An Evolving Hazardous Material Threat and Unconventional Weapon

    Jones, Robert MD

    2010-05-01

    Full Text Available Chlorine gas represents a hazardous material threat from industrial accidents and as a terrorist weapon. This review will summarize recent events involving chlorine disasters and its use by terrorists, discuss pre-hospital considerations and suggest strategies for the initial management for acute chlorine exposure events. [West J Emerg Med. 2010; 11(2:151-156.

  10. Control Decisions for Flammable Gas Hazards in Waste Transfer Systems

    This report describes the control decisions for flammable gas hazards in waste transfer systems (i.e., waste transfer piping and waste transfer-associated structures) made at control decision meetings on November 30, 1999a and April 19, 2000, and their basis. These control decisions, and the analyses that support them, will be documented in an amendment to the Final Safety Analysis Report (FSAR) (CHG 2000a) and Technical Safety Requirements (TSR) (CHG 2000b) to close the Flammable Gas Unreviewed Safety Question (USQ) (Bacon 1996 and Wagoner 1996). Following the Contractor Tier I review of the FSAR and TSR amendment, it will be submitted to the US. Department of Energy (DOE), Office of River Protection (ORP) for review and approval. The control decision meeting on November 30, 1999 to address flammable gas hazards in waste transfer systems followed the control decision process and the criteria for control decisions described in Section 3.3.1.5 of the FSAR. The control decision meeting agenda, attendance list, and introductory and background presentations are included in Attachments 1 through 4. The control decision discussions on existing and other possible controls for flammable gas hazards in waste transfer systems and the basis for selecting or not selecting specific controls are summarized in this report

  11. Acid Gas Removal from Natural Gas with Alkanolamines

    Sadegh, Negar

    Some 40 % of the world’s remaining gas reserves are sour or acid, containing large quantities of CO2 and H2S and other sulfur compounds. Many large oil and gas fields have more than 10 mole % CO2 and H2S content. In the gas processing industry absorption with chemical solvents has been used...... commercially for the removal of acid gas impurities from natural gas. Alkanolamines, simple combinations of alcohols and ammonia, are the most commonly used category of chemical solvents for acid gas capture. This Ph.D. project is aboutthermodynamics of natural gas cleaning process with alkanolamines as...... pressure on acid gas solubility was also quantitatively investigated through both experimental and modeling approaches....

  12. Survey of gas turbine hazardous air pollutant emission factors

    Hazardous air pollutant (HAP) emission factors from natural gas and liquid fueled turbines have been determined by surveying the literature and combining available data. Of the 189 US EPA HAPs, only a few have been found in turbine exhaust at concentrations above ambient levels. Test data are available from several different turbine models burning natural gas and distillate oils, but data at part loads is limited, and data from newer, dry low NOx turbines is virtually non-existent. Most of the liquid fueled turbine data is from military aircraft engines and small (less than 20 MW) stationary units. All of the data was critically evaluated, but only a small fraction was judged of poor quality and, therefore, excluded from this study. Mean HAP emissions from natural gas fired turbines are very low at base load, totaling only about 0.5 ppm by weight (ppmw), or 21 pounds of HAPs per million (MM) pounds of fuel. Median HAP emissions from natural gas fired turbines are even lower, totaling only about 0.02 ppmw, or 0.8 lb HAPs/MM lb fuel. The difference between the mean and the median reflects the relatively large number of observations that are reported as below detectable levels. Mean and median HAP emissions from liquid fueled turbines are slightly higher than natural gas fired turbine emissions. Of the organic compounds found in turbine exhaust, formaldehyde is one of the most abundant. Other HAPs found in turbine exhaust include nickel, phosphorus, and manganese. The limited part load data suggests that organic HAP emissions increase as load decreases, while inorganic HAP emissions remain constant or decrease slightly as load decreases

  13. Hydrofluoric acid dissolution of spent radioactive and hazardous HEPA filters

    This document discusses a process that treats High Efficiency Particulate Air (HEPA) filters contaminated with radioactive particles containing transuranic and hazardous elements which has been studied at the Idaho Chemical Processing Plant (ICPP). This process uses three to four steps to spent HEPA filter so that they meet regulatory requirements for disposal. The first step of the process is to bake the spent HEPA filters at 550 degrees C for 3 hours to volatilize organic binder which is used to provide strength in the filter's silicon glass media. In the second step, the filters are first leached in nitric acid, then are dissolved in hydrofluoric acid. The dissolution is conducted using an optimum fluoride to silicone molar ratio of 7/1 to prevent: (1) excess unreacted HF (free HF), (2) the formation of insoluble fluoride salts, and (3) the need of excessive aluminum nitrate to complex the free HF. Finally, the free HF is complexed with aluminum nitrate to an [HF] between 0.020 and 0.04 molar. The resulting solution from this process is minimally corrosive to stainless steel and is a stable high-level liquid waste that can be converted to a high-level solid waste in a fluidized bed operated at 500 degrees C. The stainless steel HEPA filter housing, which is not dissolved during the dissolution step, is compacted and disposed of as a nonhazardous, low-level radioactive waste

  14. Nanostructure Engineered Chemical Sensors for Hazardous Gas and Vapor Detection

    Li, Jing; Lu, Yijiang

    2005-01-01

    A nanosensor technology has been developed using nanostructures, such as single walled carbon nanotubes (SWNTs) and metal oxides nanowires or nanobelts, on a pair of interdigitated electrodes (IDE) processed with a silicon based microfabrication and micromachining technique. The IDE fingers were fabricated using thin film metallization techniques. Both in-situ growth of nanostructure materials and casting of the nanostructure dispersions were used to make chemical sensing devices. These sensors have been exposed to hazardous gases and vapors, such as acetone, benzene, chlorine, and ammonia in the concentration range of ppm to ppb at room temperature. The electronic molecular sensing in our sensor platform can be understood by electron modulation between the nanostructure engineered device and gas molecules. As a result of the electron modulation, the conductance of nanodevice will change. Due to the large surface area, low surface energy barrier and high thermal and mechanical stability, nanostructured chemical sensors potentially can offer higher sensitivity, lower power consumption and better robustness than the state-of-the-art systems, which make them more attractive for defense and space applications. Combined with MEMS technology, light weight and compact size sensors can be made in wafer scale with low cost.

  15. Thermal Hazard Evaluation of Lauroyl Peroxide Mixed with Nitric Acid

    Chi-Min Shu

    2012-07-01

    Full Text Available Many thermal runaway incidents have been caused by organic peroxides due to the peroxy group, –O–O–, which is essentially unstable and active. Lauroyl peroxide (LPO is also sensitive to thermal sources and is incompatible with many materials, such as acids, bases, metals, and ions. From the thermal decomposition reaction of various concentrations of nitric acid (HNO3 (from lower to higher concentrations with LPO, experimental data were obtained as to its exothermic onset temperature (T0, heat of decomposition (ΔHd, isothermal time to maximum rate (TMRiso, and other safety parameters exclusively for loss prevention of runaway reactions and thermal explosions. As a novel finding, LPO mixed with HNO3 can produce the detonation product of 1-nitrododecane. We used differential scanning calorimetry (DSC, thermal activity monitor III (TAM III, and gas chromatography/mass spectrometer (GC/MS analyses of the reactivity for LPO and itself mixed with HNO3 to corroborate the decomposition reactions and reaction mechanisms in these investigations.

  16. Thermal hazard evaluation of lauroyl peroxide mixed with nitric acid.

    Tsai, Lung-Chang; You, Mei-Li; Ding, Mei-Fang; Shu, Chi-Min

    2012-01-01

    Many thermal runaway incidents have been caused by organic peroxides due to the peroxy group, -O-O-, which is essentially unstable and active. Lauroyl peroxide (LPO) is also sensitive to thermal sources and is incompatible with many materials, such as acids, bases, metals, and ions. From the thermal decomposition reaction of various concentrations of nitric acid (HNO3) (from lower to higher concentrations) with LPO, experimental data were obtained as to its exothermic onset temperature (T0), heat of decomposition (ΔHd), isothermal time to maximum rate (TMRiso), and other safety parameters exclusively for loss prevention of runaway reactions and thermal explosions. As a novel finding, LPO mixed with HNO3 can produce the detonation product of 1-nitrododecane. We used differential scanning calorimetry (DSC), thermal activity monitor III (TAM III), and gas chromatography/mass spectrometer (GC/MS) analyses of the reactivity for LPO and itself mixed with HNO3 to corroborate the decomposition reactions and reaction mechanisms in these investigations. PMID:22763742

  17. Research on safety assessment of gas explosion hazard in heading face based on BP neural network

    TIAN Shui-cheng; ZHU Li-jun; CHEN Yong-gang; WANG Li

    2005-01-01

    According to hazard theory and the principle of selecting assessment index,combining the causes and mechanism of gas explosion, established assessment index system of gas explosion in heading face. Based on the method of gray clustering, principle of BP neural network and characters of gas explosion in heading face, safety assessment procedural diagram of BP neural network on gas explosion hazard in heading face is designed. Meanwhile, concrete heading face of the gas explosion hazard is assessed by safety assessment method of BP neural network and grades of comprehensive safety assessment are got. The static and dynamic safety assessment can be achieved by this method. It is practical to improve safety management and to develop safety assessment technology in coalmine.

  18. Inert gas spraying device aids in repair of hazardous systems

    Teleha, S.

    1965-01-01

    Inert gas spraying device aids in safely making mechanical repairs to a cryogenic fluid system without prior emptying of the system. This method can be applied to any natural or bottled gas system and with modifications to gasoline transports.

  19. Gas chromatography of alkylphosphonic and dialkylphosphinic acids

    After carrying out an optimization study on the separation conditions for the TMS-derivatives, of the hexyl-, cyclohexyl-, heptyl-, and octyl-phosphonic acids; dihexyl-, dicyclohexyl-, heptyl-, and octyl-phosphinic acids, and dioctylphosphine oxide, their retention indices (I) at two temperatures and on the 0V-1 and 0V-17 stationary phase were determined. Correlations between I and molecular structure were established. Calibration factors of these compounds in the flame ionization detector were studied, and the results analized taking into account the variables afecting the quantitative results. These results were unbiased but they had a lower precission than usually achieveble in gas chromatography. (author)

  20. The gas-phase acidity of nitrocyclopropane

    Bartmess, John E.; Wilson, Burton; Sorensen, Daniel N.; Bloor, John E.

    1992-09-01

    Nitrocyclopropane is 10.5 kcal mol-1 weaker as an acid in the gas phase than its open-chain analog, 2-nitropropane. This is attributed to the conflicting hybridization requirements for carbanion stabilization by the cyclopropyl ring and by the nitro group. Based on reactivities, the deprotonated form does not ring-open to either the 2-nitroallyl anion or the 1-nitroallyl anion.

  1. Evaluation of Hazard of Mine Gas emissions at the Surface

    Urban Petr

    2004-01-01

    The paper presents principles of the method of measuring the concentration and the flow rate of gas emitted from various underground spaces by new evaluation criteria, however mainly from the point of view of consequences of risks associated with gas emissions in semiclosed and closed spaces, in areas affected by the mining of mineral raw materials or mining claims already abandoned.The paper gives the information about the objectives and principles of the method of measuring the concentratio...

  2. Capture and release of acid-gasses with acid-gas binding organic compounds

    Heldebrant, David J; Yonker, Clement R; Koech, Phillip K

    2015-03-17

    A system and method for acid-gas capture wherein organic acid-gas capture materials form hetero-atom analogs of alkyl-carbonate when contacted with an acid gas. These organic-acid gas capture materials include combinations of a weak acid and a base, or zwitterionic liquids. This invention allows for reversible acid-gas binding to these organic binding materials thus allowing for the capture and release of one or more acid gases. These acid-gas binding organic compounds can be regenerated to release the captured acid gasses and enable these organic acid-gas binding materials to be reused. This enables transport of the liquid capture compounds and the release of the acid gases from the organic liquid with significant energy savings compared to current aqueous systems.

  3. Development of an intelligent hypertext manual for the space shuttle hazardous gas detection system

    Lo, Ching F.; Shi, George Z.; Bangasser, Carl; Fensky, Connie

    A computer-based Integrated Knowledge System (IKS), the Intelligent Hypertext Manual (IHM), is being developed for the Space Shuttle Hazardous Gas Detection System (HGDS) at the Huntsville Operations Support Center (HOSC). The IHM stores all HGDS related knowledge and presents them in an interactive and intuitive manner. The IHM's purpose is to provide HGDS personnel with the capabilities of: enhancing the interpretation of real time data; recognizing and identifying possible faults in the Space Shuttle sub-system related to hazardous gas detections; locating applicable documentation related to procedures, constraints, and previous fault histories; and assisting in the training of personnel.

  4. Hazard of ultraviolet radiation emitted in gas tungsten arc welding of aluminum alloys.

    Nakashima, Hitoshi; Utsunomiya, Akihiro; Fujii, Nobuyuki; Okuno, Tsutomu

    2016-03-28

    Ultraviolet radiation (UVR) emitted during arc welding frequently causes keratoconjunctivitis and erythema. The extent of the hazard of UVR varies depending on the welding method and conditions. Therefore, it is important to identify the levels of UVR that are present under various conditions. In this study, we experimentally evaluated the hazard of UVR emitted in gas tungsten arc welding (GTAW) of aluminum alloys. The degree of hazard of UVR is measured by the effective irradiance defined in the American Conference of Governmental Industrial Hygienists guidelines. The effective irradiances measured in this study are in the range 0.10-0.91 mW/cm(2) at a distance of 500 mm from the welding arc. The maximum allowable exposure times corresponding to these levels are only 3.3-33 s/day. This demonstrates that unprotected exposure to UVR emitted by GTAW of aluminum alloys is quite hazardous in practice. In addition, we found the following properties of the hazard of UVR. (1) It is more hazardous at higher welding currents than at lower welding currents. (2) It is more hazardous when magnesium is included in the welding materials than when it is not. (3) The hazard depends on the direction of emission from the arc. PMID:26632121

  5. Investigating animal health effects of sour gas acid forming emissions

    The effects of sour gas well blowout emissions on livestock are reviewed. Guidelines for safe drilling operations in hydrogen sulfide environments, general hazards and characteristics of hydrogen sulfide, and guidelines for field investigation into the effects of sour gas and acid emissions on livestock are discussed. A case history involving the Ross No. 2 gas well blowout of July 1985 in Rankin County, Mississippi is presented. The blowout lasted for 72 days, and at peak discharge the 500 ppM radius was ca 3.5 miles. A cattle embryo transplant operation located one half mile from the well was affected by the blowout. Examination by a local veterinarian of the cattle demonstrated eye irritation, epiphora, nasal discharge and coughing. After one and a half months of exposure, most animals showed clinical signs of a severe dry hacking cough, epiphora, dry rales over the thoracic inlet, and a bronchial popping sound over the lateral thorax. All animals had eye irritation. Of 55 animals showing signs of respiratory distress and eye irritations, 15 were still clinically ill in May of 1986. 7 refs., 1 tab

  6. Uncertainties in modeling hazardous gas releases for emergency response

    Baumann-Stanzer, Kathrin; Stenzel, Sirma [Zentralanstalt fuer Meteorologie und Geodynamik, Vienna (Austria)

    2011-02-15

    In case of an accidental release of toxic gases the emergency responders need fast information about the affected area and the maximum impact. Hazard distances calculated with the models MET, ALOHA, BREEZE, TRACE and SAMS for scenarios with chlorine, ammoniac and butane releases are compared in this study. The variations of the model results are measures for uncertainties in source estimation and dispersion calculation. Model runs for different wind speeds, atmospheric stability and roughness lengths indicate the model sensitivity to these input parameters. In-situ measurements at two urban near-traffic sites are compared to results of the Integrated Nowcasting through Comprehensive Analysis (INCA) in order to quantify uncertainties in the meteorological input. The hazard zone estimates from the models vary up to a factor of 4 due to different input requirements as well as due to different internal model assumptions. None of the models is found to be 'more conservative' than the others in all scenarios. INCA wind-speeds are correlated to in-situ observations at two urban sites in Vienna with a factor of 0.89. The standard deviations of the normal error distribution are 0.8 ms{sup -1} in wind speed, on the scale of 50 degrees in wind direction, up to 4 C in air temperature and up to 10 % in relative humidity. The observed air temperature and humidity are well reproduced by INCA with correlation coefficients of 0.96 to 0.99. INCA is therefore found to give a good representation of the local meteorological conditions. Besides of real-time data, the INCA-short range forecast for the following hours may support the action planning of the first responders. (orig.)

  7. Acid sulfate soils are an environmental hazard in Finland

    Pihlaja, Jouni

    2016-04-01

    Acid sulfate soils (ASS) create significant threats to the environment on coastal regions of the Baltic Sea in Finland. The sediments were deposited during the ancient Litorina Sea phase of the Baltic Sea about 7500-4500 years ago. Finland has larger spatial extent of the ASS than any other European country. Mostly based on anthropogenic reasons (cultivation, trenching etc.) ASS deposits are currently being exposed to oxygen which leads to chemical reaction creating sulfuric acid. The acidic waters then dissolve metals form the soil. Acidic surface run off including the metals are then leached into the water bodies weakening the water quality and killing fish or vegetation. In constructed areas acidic waters may corrode building materials. Geological Survey of Finland (GTK) is mapping ASS deposits in Finland. The goal is to map a total of 5 million hectares of the potentially ASS affected region. It has been estimated that the problematic Litorina Sea deposits, which are situated 0-100 m above the recent Baltic Sea shoreline, cover 500 000 hectares area. There are several phases in mapping. The work begins at the office with gathering the existing data, interpreting airborne geophysical data and compiling a field working plan. In the field, quality of the soil is studied and in uncertain cases samples are taken to laboratory analyses. Also electrical conductivity and pH of soil and water are measured in the field. Laboratory methods include multielemental determinations with ICP-OES, analyses of grain size and humus content (LOI), and incubation. So far, approximately 60 % of the potential ASS affected regions in Finland are mapped. Over 15 000 sites have been studied in the field and 4000 laboratory analyses are done. The spatial database presented in the scale of 1: 250 000 can be viewed at the GTK's web pages (http://gtkdata.gtk.fi/hasu/index.html).

  8. The issues surrounding a shallow gas database in relation to offshore hazards

    Holmes, R.; Alexander, S.; Ball, K.; Bulat, J.; Evans, R.; Long, D.; MacBeth, C.; McCormac, M.; Sankey, M.

    1998-02-01

    The aim of this report is to objectively review the current issues identified by operators, contractors, consultants and the Health and Safety Executive that are relevant to a shallow gas database, and so identify possible ways forward to address the safety concerns of the offshore oil and gas industry. Background information summarizing some of the current methods used to predict and detect shallow gas is used to demonstrate the potential scope for a database. The safety objective is achieved by approaches to approved contacts in the offshore oil and gas industry for their opinions on the needs, standards, procedures and the perceived utilisation and benefits associated with a possible shallow gas database. These opinions are compiled then reviewed in relation to the issues identified by industry and the Offshore Safety Division, Health and Safety Executive. Contact with industry and the Offshore Safety Division, Health and Safety Executive demonstrates a clear concern about the immediate threat to drilling operations from shallow gas. There is less industry concern about the need to address the threat to health and safety arising from the hazards posed by shallow gas to production facilities. In this last case, some concern is associated with engineering design, including the longer-term hazards to foundations from shallow gas. (author)

  9. Studying of acid-gas pipelines corrosion with impedance spectroscopy

    Neshati, J.; Fardi, M.R.; Ghassem, H. [Corrosion Department, NIOC-RIPI, Pazhooheshgah Bulevard, Khairabad Junction, Old Qom Road Tehran (Iran)

    2004-07-01

    In this research, the acid-gas pipelines of a gas refinery were simulated in laboratory. Acid gas is normally the feed of sulfur recovery plant (SRP) in a gas refinery. For studying corrosion kinetic and related mechanisms the impedance spectroscopy was used. Impedance diagrams were simulated by Boukamp1988 software. It was found that the simulated systems can be equated to a circuit with two time constants. For studying corrosion rate changes a type of inhibitor was utilized. The inhibitor used in this work was an imidazoline, an appropriate based inhibitor formulated with the commercial grade imidazoline and dimmer - trimer acid. It was shown that impedance spectroscopy technique can be used for corrosion monitoring of acid gas pipelines in gas refineries. The impedance spectroscopy will be tried in due course as a suitable technique in field for corrosion control of acid-gas pipelines. (authors)

  10. Hazardous gas treatment using atmospheric pressure microwave discharges

    Mizeraczyk, Jerzy; Jasinski, Mariusz; Zakrzewski, Zenon [Centre for Plasma and Laser Engineering, Institute of Fluid Flow Machinery, Polish Academy of Sciences, Fiszera 14, 80-231 Gdansk (Poland)

    2005-12-15

    Atmospheric pressure microwave discharge methods and devices used for producing non-thermal plasmas for control of gaseous pollutants are described in this paper. The main part of the paper is concerned with microwave torch discharges (MTDs). Results of laboratory experiments on plasma abatement of several volatile organic compounds (VOCs) in their mixtures with either synthetic air or nitrogen in low ({approx}100 W) and moderate (200-400 W) microwave torch plasmas at atmospheric pressure are presented. Three types of MTD generators, i.e. low-power coaxial-line-based MTDs, moderate-power waveguide-based coaxial-line MTDs and moderate-power waveguide-based MTDs were used. The gas flow rate and microwave (2.45 GHz) power delivered to the discharge were in the range of 1-3 litre min{sup -1} and 100-400 W, respectively. The concentrations of the processed gaseous pollutants were from several to several tens of per cent. The results showed that the MTD plasmas fully decomposed the VOCs at a relatively low energy cost. The energy efficiency of decomposition of several gaseous pollutants reached 1000 g (kW-h){sup -1}. This suggests that MTD plasmas can be useful tools for decomposition of highly concentrated VOCs.

  11. Experimental study on thermal hazard of tributyl phosphate-nitric acid mixtures using micro calorimeter technique.

    Sun, Qi; Jiang, Lin; Gong, Liang; Sun, Jin-Hua

    2016-08-15

    During PUREX spent nuclear fuel reprocessing, mixture of tributyl phosphate (TBP) and hydrocarbon solvent are employed as organic solvent to extract uranium in consideration of radiation contaminated safety and resource recycling, meanwhile nitric acid is utilized to dissolve the spent fuel into small pieces. However, once TBP contacts with nitric acid or nitrates above 130°C, a heavy "red oil" layer would occur accompanied by thermal runaway reactions, even caused several nuclear safety accident. Considering nitric acid volatility and weak exothermic detection, C80micro calorimeter technique was used in this study to investigate thermal decomposition of TBP mixed with nitric acid. Results show that the concentration of nitric acid greatly influences thermal hazard of the system by direct reactions. Even with a low heating rate, if the concentration of nitric acid increases due to evaporation of water or improper operations, thermal runaway in the closed system could start at a low temperature. PMID:27136728

  12. Evaluation of radiation hazard potential of TENORM waste from oil and natural gas production

    In this study, a potential radiation hazard from TENORM sludge wastes generated during exploration and extraction processes of oil and gas was evaluated. The activity concentration of natural radionuclides 238U, 226Ra and 232Th were determined in TENORM sludge waste. It was found that sludge waste from oil and gas industry is one of the major sources of 226Ra in the environment. Therefore, some preliminary chemical treatment of sludge waste using Triton X-100 was also investigated to reduce the radioactivity content as well as the risk of radiation hazard from TENORM wastes. The activity concentrations of 226Ra and 228Ra in petroleum sludge materials before and after chemical treatment were measured using gamma-ray spectrometry. The average values of the activity concentrations of 226Ra and 228Ra measured in the original samples were found as 8908 Bq kg−1 and 933 Bq kg−1, respectively. After chemical treatment of TENORM samples, the average values of the activity concentrations of 226Ra and 228Ra measured in the samples were found as 7835 Bq kg−1 and 574 Bq kg−1, respectively. Activity concentration index, internal index, absorbed gamma dose rate and the corresponding effective dose rate were estimated for untreated and treated samples. - Highlights: • Petroleum industry has been generated huge amount of natural occurring radioactive material. • Estimation of radiation hazards and environmental impact of TENORM sludge wastes. • New approach for decreasing the radioactivity content in TENORM sludge wastes

  13. Acid-gas injection in the Long Coulee Glauconite F Pool, Alberta : implications for enhanced gas recovery and acid-gas disposal

    Acid gas disposal in depleted oil and gas reservoirs is now being used as a means of safely and economically reducing acid gas emissions into the environment. Acid gas is currently being disposed into the Long Coulee Glauconite F pool in southern Alberta. The pool consists of a small oil leg and a large gas cap trapped in quartz arenite. In this study, reservoir mapping and permeability and porosity measurements were used to model the acid gas flow of a 98 per cent carbon dioxide (CO2) and 2 per cent hydrogen sulfide (H2S) mixture in order to determine the effects of acid gas injection on reservoir performance and recovery rates. The study demonstrated that acid gas injection resulted in increased gas recovery even with rapid CO2 breakthrough at offsetting gas producers. CO2 breakthrough occurred faster than H2S breakthrough. Gas partitioning occurred as a result of the preferential solubility of H2S in the formation brine. It was concluded that acid gas injection results in the partial re-pressurization of the gap cap.

  14. Acid-gas injection in the Long Coulee Glauconite F Pool, Alberta : implications for enhanced gas recovery and acid-gas disposal

    Dashtgard, S. [Simon Fraser Univ., Burnaby, BC (Canada); Pooladi-Darvish, M; Hong, H.; Theys, S.; Stocker, R. [Fekete Associates Inc., Calgary, AB (Canada); Bachu, S. [Energy Resources Conservation Board, Calgary, AB (Canada)

    2008-07-01

    Acid gas disposal in depleted oil and gas reservoirs is now being used as a means of safely and economically reducing acid gas emissions into the environment. Acid gas is currently being disposed into the Long Coulee Glauconite F pool in southern Alberta. The pool consists of a small oil leg and a large gas cap trapped in quartz arenite. In this study, reservoir mapping and permeability and porosity measurements were used to model the acid gas flow of a 98 per cent carbon dioxide (CO{sub 2}) and 2 per cent hydrogen sulfide (H{sub 2}S) mixture in order to determine the effects of acid gas injection on reservoir performance and recovery rates. The study demonstrated that acid gas injection resulted in increased gas recovery even with rapid CO{sub 2} breakthrough at offsetting gas producers. CO{sub 2} breakthrough occurred faster than H{sub 2}S breakthrough. Gas partitioning occurred as a result of the preferential solubility of H{sub 2}S in the formation brine. It was concluded that acid gas injection results in the partial re-pressurization of the gap cap.

  15. Appraisal of possible combustion hazards associated with a high-temperature gas-cooled reactor

    The report presents a study of combustion hazards that may be associated with the High Temperature Gas Cooled Reactor (HTGR) in the event of a primary coolant circuit depressurization followed by water or air ingress into the prestressed concrete reactor vessel (PCRV). Reactions between graphite and steam or air produce the combustible gases H2 and/or CO. When these gases are mixed with air in the containment vessel (CV), flammable mixtures may be formed. Various modes of combustion including diffusion or premixed flames and possibly detonation may be exhibited by these mixtures. These combustion processes may create high over-pressure, pressure waves, and very hot gases within the CV and hence may threaten the structural integrity of the CV or damage the instrumentation and control system installations within it. Possible circumstances leading to these hazards and the physical characteristics related to them are delineated and studied in the report

  16. A summary of geologic hazards for proposed OCS oil and gas lease sale 68, southern California

    Burdick, Deborah J.; Richmond, William C.

    1982-01-01

    A geophysical survey, consisting of about 6,880 line-km of multisensor, high-resolution, seismic reflection data, was run in 161 of the 221 tracts tentatively selected by the U.S. Department of the Interior for inclusion in the southern California Outer Continental Shelf Oil and Gas Lease Sale 68. Geologic hazards identified in the study area for which stipulations are recommended are active faults, mass transport, steep slopes (>10?), and steep-walled submarine canyons. Geologic hazards whose effects can be mitigated through existing technology and design and are not considered cause for stipulation are shallow faults, buried and filled channels, shallow gas, gas-charged sediments, hydrocarbon seeps, and unstable fan deposits. The Minerals Management Service has recommended that a stipulation be applied to 83 tracts where there is evidence of existing or potential sea-floor instability over a significant portion of the tract. Further data acquisition and analysis on a more detail-ed grid will be required of lessees or operators before drilling will be permitted on leases issued as a result of the sale.

  17. Determination of Fatty Acid in Asparagus by Gas Chromatography

    Zehra HAJRULAI-MUSLIU

    2016-05-01

    Full Text Available Asparagus contain a lot of macronutrients and micronutrients including folate, dietary fibre (soluble and insoluble and phenolic compounds. Also asparagus is a good source of unsaturated linoleic and linolenic fatty acids which are precursors for Eicosapentanoic acid (EPA and Docosahexanoic acid (DHA. Unsaturated fatty acids have important biological effects and they have important role in human health. The objective of this study was to analyze fatty acid composition of asparagus as a potential source of linoleic and linolenic acid - a precursor for EPA and DHA. For this reason we analyzed fifty seven samples of asparagus collected from the local market. We used AOAC 996.06 method and analyses were performed with gas chromatograph with flame-ionization detector (GC-FID. The highest concentration of fatty acid in the asparagus was linoleic acid (C18:2n6 which content in asparagus is 25.620±1.0%. Also, asparagus is good source of -linolenic fatty acid (C18:3n3 and content of this fatty acid in asparagus is 8.840±0.3%. The omega-6 to omega-3 (n6/n3 ratio in asparagus was 3.19. Polyunsaturated fatty acids (PUFAs were higher than monounsaturated fatty acids (MUFAs, and from saturated fatty acids, palmitic acid was most frequent with 24.324±1.0%. From our study we can conclude that asparagus is very good source of unsaturated fatty acids, especially linoleic and linolenic fatty acids.

  18. Control Decisions for Flammable Gas Hazards in Double Contained Receiver Tanks (DCRTs)

    KRIPPS, L.J.

    2000-06-28

    This report describes the control decisions for flammable gas hazards in double-contained receiver tanks (DCRTs) made at control decision meetings on November 16, 17, and 18, 1999, on April 19,2000, and on May 10,2000, and their basis. These control decisions, and the analyses that support them, will be documented in an amendment to the Final Safety Analysis Report (FSAR) (CHG 2000a) and Technical Safety Requirements (TSR) (CHG 2000b) to close the Flammable Gas Unreviewed Safety Question (USQ) (Bacon 1996 and Wagoner 1996) for DCRTs. Following the contractor Tier I review of the FSAR and TSR amendment, it will be submitted to the U.S. Department of Energy (DOE), Office of River Protection (ORP) for review and approval.

  19. Diglycolamic acid modified silica gel for the separation of hazardous trivalent metal ions from aqueous solution.

    Suneesh, A S; Syamala, K V; Venkatesan, K A; Antony, M P; Vasudeva Rao, P R

    2015-01-15

    The surface of the silica gel was modified with diglycolamic acid moieties and the product (Si-DGAH) was characterized by elemental analysis, TG-DTA, (1)H and (29)Si NMR and scanning electron microscopy (SEM). The adsorption behavior of hazardous americium (III) and europium (III) in Si-DGAH was studied from aqueous nitric acid medium to examine the feasibility using the modified silica for the separation of Am(III) and Eu(III) from aqueous wastes. In this context, the effect of various parameters such as the duration of equilibration, and concentrations of europium, nitric acid, sodium nitrate and diethylenetriaminepentaacetic acid (DTPA) in aqueous phase, on the distribution coefficient (K(d)) of Am(III) and Eu(III) was investigated. The distribution coefficient of ∼10(3) mL/g (>99.9% extraction) was obtained for both Am(III) and Eu(III) at pH 3, and the K(d) values decreased with increase in the concentration of nitric acid. Rapid kinetics of extraction in the initial stages of equilibration, followed by the establishment of equilibrium occurred within 30 min. The extraction data were fitted into Langmuir adsorption model and the apparent europium extraction capacity was determined. Europium loading capacity of the sorbent was determined at various feed pH by column method. The study indicated the possibility of using diglycolamic acid-modified silica for the separation of Eu(III) and Am(III) from aqueous wastes. PMID:25454425

  20. Polymeric supported sorbents for decreasing hazardous metal ions content in wet process phosphoric acid

    Procedure for preparation of polymeric supported silica, and their usage for decreasing hazardous metal ion content in wet process phosphoric acid was developed. The procedure is based firstly on extraction silica from rice straw by alkaline treatment , secondly supporting the produced silica on binding polyacrylonitrile (PAN). The produced polymer based sorbent was used for decreasing hazardous metal ions (especially iron) present as inorganic impurities in crud Egyptian phosphoric acid (green acid). Different factors affecting the sorption equilibrium ( contact time, temperature , sorbent mass and batch factor ) were studied. Studying the sorption isotherm revealed that the adsorption data could favorably fit the Langmuir adsorption isotherm. In the dynamic study , the sorption capacity at (Cξ/Cο = 50%) was found to be 28.5 mg/g and the loaded column could be regenerated using 50ml of 0.15 M HNO3 . The regenerated column could undergo sorption regeneration cycles up to four cycles without significant decrease in the sorption capacity , weight loss or change in the physical properties of the sorbent

  1. Sensor Array Devices Utilizing Nano-structured Metal-oxides for Hazardous Gas Detection

    Andio, Mark A.

    Methane and carbon monoxide are two hazardous gases which require continuous monitoring by gas sensors in underground coal mines for explosion prevention and toxicity, respectively. This work explored implementing miniaturized gas sensors in this area to simultaneously detect both gases for benefits of increased portability and reduced power consumption of the chemiresistive gas sensor device. The focus of this research was to understand how the particle size, morphology, and microstructure of the metaloxide film affected the gas sensor performance to the two gases of interest on miniaturized gas sensor devices in the form of microhotplate platforms. This was done through three main research studies. The first was conducted by growing SnO2 nanowires from SnO 2 particles using an Au-catalyst. Growth conditions including temperature, time, and oxygen partial pressure were explored to determine the formation aspects of the SnO2 nanowires. Gas sensor studies were completed that provided evidence that the SnO2 nanowires increased detection to a fixed concentration of carbon monoxide compared to SnO2 particles without nano-structure formation. A second research study was performed to compare the gas sensor performance of SnO2 nanoparticles, hierarchical particles, and micron-size particles. The nanoparticles were developed into an ink and deposited via ink-jet printing on the microhotplate substrates to control the microstructure of the metal-oxide film. By preventing agglomeration of the nanoparticle film, the SnO2 nanoparticles displayed similar gas sensor performance to methane and carbon monoxide as the hierarchical particles. Both nano-structures had much higher gas sensor response than the micron-size particles which confirms the surface area of the metal-oxide film is critical for reaction of the analyte gas at the surface. The last research study presented in the dissertation describes an oxide nanoparticle array developed for detecting methane and carbon

  2. Gas hazard assessment in a densely inhabited area of Colli Albani Volcano (Cava dei Selci, Roma)

    Carapezza, M. L.; Badalamenti, B.; Cavarra, L.; Scalzo, A.

    2003-04-01

    The northwestern flank of the Colli Albani, a Quaternary volcanic complex near Rome, is characterised by high pCO 2 values and Rn activities in the groundwater and by the presence of zones with strong emission of gas from the soil. The most significant of these zones is Cava dei Selci where many houses are located very near to the gas emission site. The emitted gas consists mainly of CO 2 (up to 98 vol%) with an appreciable content of H 2S (0.8-2%). The He and C isotopic composition indicates, as for all fluids associated with the Quaternary Roman and Tuscany volcanic provinces, the presence of an upper mantle component contaminated by crustal fluids associated with subducted sediments and carbonates. An advective CO 2 flux of 37 tons/day has been estimated from the gas bubbles rising to the surface in a small drainage ditch and through a stagnant water pool, present in the rainy season in a topographically low central part of the area. A CO 2 soil flux survey with an accumulation chamber, carried out in February-March 2000 over a 12 000 m 2 surface with 242 measurement points, gave a total (mostly conductive) flux of 61 tons/day. CO 2 soil flux values vary by four orders of magnitude over a 160-m distance and by one order of magnitude over several metres. A fixed network of 114 points over 6350 m 2 has been installed in order to investigate temporal flux variations. Six surveys carried out from May 2000 to June 2001 have shown large variations of the total CO 2 soil flux (8-25 tons/day). The strong emission of CO 2 and H 2S, which are gases denser than air, produces dangerous accumulations in low areas which have caused a series of lethal accidents to animals and one to a man. The gas hazard near the houses has been assessed by continuously monitoring the CO 2 and H 2S concentration in the air at 75 cm from the ground by means of two automatic stations. Certain environmental parameters (wind direction and speed; atm P, T, humidity and rainfall) were also

  3. The Role of Deposition in Limiting the Hazard Extent of Dense-Gas Plumes

    Dillon, M B

    2008-05-11

    Accidents that involve large (multi-ton) releases of toxic industrial chemicals and form dense-gas clouds often yield far fewer fatalities, casualties and environmental effects than standard assessment and emergency response models predict. This modeling study, which considers both dense-gas turbulence suppression and deposition to environmental objects (e.g. buildings), demonstrates that dry deposition to environmental objects may play a significant role in reducing the distance at which adverse impacts occur - particularly under low-wind, stable atmospheric conditions which are often considered to be the worst-case scenario for these types of releases. The degree to which the released chemical sticks to (or reacts with) environmental surfaces is likely a key parameter controlling hazard extents. In all modeled cases, the deposition to vertical surfaces of environmental objects (e.g. building walls) was more efficient in reducing atmospheric chemical concentrations than deposition to the earth's surface. This study suggests that (1) hazard extents may vary widely by release environment (e.g. grasslands vs. suburbia) and release conditions (e.g. sunlight or humidity may change the rate at which chemicals react with a surface) and (2) greenbelts (or similar structures) may dramatically reduce the impacts of large-scale releases. While these results are demonstrated to be qualitatively consistent with the downwind extent of vegetation damage in two chlorine releases, critical knowledge gaps exist and this study provides recommendations for additional experimental studies.

  4. Organic acids emissions from natural-gas-fed engines

    Zervas, Efthimios; Tazerout, Mohand

    A natural-gas-fed spark-ignition engine, operating under lean conditions, is used for the study of the organic acids exhaust emissions. These pollutants are collected by passing a sample of exhaust gas into deionised water. The final solution is directly analysed by HPLC/UV at 204 nm. Only formic acid is emitted in detectable concentration under the experimental conditions used. Its concentration decreases with the three engine operating parameters studied: spark advance, volumetric efficiency and fuel/air equivalence ratio. Exhaust formic acid concentration is also linked with exhaust oxygen concentration and exhaust temperature. A comparison with other engines (SI engines fed with gasoline and compression ignition engines) from bibliographic data proves that natural-gas-fed engines emit less organic acids than the other two types of engines.

  5. Hazardous waste disposal in relationship to radon gas emanation in atmosphere

    Radioactive/toxic radon gas (Rn) produced naturally in the ground by the normal decay of uranium (U) and radium (Ra) is widely distributed in trace amounts in the earth's crust. It is a colorless, odorless and tasteless element and is one of the six generally known noble gases which are inert gases lacking the usual or anticipated chemical or biological action. Most radon gas is concentrated in the oxidation belt which is at a relatively shallow depth from the ground surface. Under normal conditions, the amount of radon gas seeping into the atmosphere or entering into residential buildings is very little and will not be harmful to human health. In recent years, due to population growth, a progressive living standard and industrial progress, many natural farm lands, forests and wetlands have been destroyed by conversion into residential and industrial compounds; consequently, such construction activities and industrial waste disposal changes the dynamic equilibrium of the ecosystem which can trigger and accelerate radon gas emanation and mobilization. This change is the major reason for the problem of indoor radon concentration which has significantly increased in recent years. Recent findings indicate that radon is not a totally inert element as previously thought. It can be influenced by local environments such as temperature, pH value, ion exchange, redox reaction, etc. to some degree. Also radon gas interacts with soil, water, air and others; unfortunately, the interface mechanisms between radon and the environment are not yet clearly understood and little information on these aspects is available. In this paper only the hazardous waste disposal causes for radon emanation are discussed. To deal with such complex phenomena, a new approach is presented that assumes radon gas interaction with the environment through dust in the air and suspensions in the water and soil-water system

  6. The spatiotemporal characteristics of environmental hazards caused by offshore oil and gas operations in the Gulf of Mexico.

    Meng, Qingmin

    2016-09-15

    Marine ecosystems are home to a host of numerous species ranging from tiny planktonic organisms, fishes, and birds, to large mammals such as the whales, manatees, and seals. However, human activities such as offshore oil and gas operations increasingly threaten marine and coastal ecosystems, for which there has been little exploration into the spatial and temporal risks of offshore oil operations. Using the Gulf of Mexico, one of the world's hottest spots of offshore oil and gas mining, as the study area, we propose a spatiotemporal approach that integrates spatial statistics and geostatistics in a geographic information system environment to provide insight to environmental management and decision making for oil and gas operators, coastal communities, local governments, and the federal government. We use the records from 1995 to 2015 of twelve types of hazards caused by offshore oil and gas operations, and analyze them spatially over a five year period. The spatial clusters of these hazards are analyzed and mapped using Getis-Ord Gi and local Moran's I statistics. We then design a spatial correlation coefficient matrix for multivariate spatial correlation, which is the ratio of the cross variogram of two types of hazards to the product of the variograms of the two hazards, showing a primary understanding of the degrees of spatial correlation among the twelve types hazards. To the best of our knowledge, it is the first application of spatiotemporal analysis methods to environmental hazards caused by offshore oil and gas operations; the proposed methods can be applied to other regions for the management and monitoring of environmental hazards caused by offshore oil operations. PMID:27213845

  7. Hazards to nuclear power plants from large liquefied natural gas (LNG) spills on water

    The hazards to nuclear power plants arising from large spills of liquefied natural gas (LNG) on water transportation routes are treated by deterministic analytical procedures. Global models, which address the salient features of the LNG spill phenomena are used in the analysis. A coupled computational model for the combined LNG spill, spreading, and fire scenario is developed. To predict the air blast environment in the vicinity of vapor clouds with pancake-like geometries, a scalable procedure using both analytical methods and hydrocode calculations is synthesized. Simple response criteria from the fire and weapons effects literature are used to characterize the susceptibility of safety-related power plant systems. The vulnerability of these systems is established either by direct comparison between the LNG threat and the susceptibility criteria or through simple response calculations. Results are analyzed

  8. Coal seam gas water: potential hazards and exposure pathways in Queensland.

    Navi, Maryam; Skelly, Chris; Taulis, Mauricio; Nasiri, Shahram

    2015-01-01

    The extraction of coal seam gas (CSG) produces large volumes of potentially contaminated water. It has raised concerns about the environmental health impacts of the co-produced CSG water. In this paper, we review CSG water contaminants and their potential health effects in the context of exposure pathways in Queensland's CSG basins. The hazardous substances associated with CSG water in Queensland include fluoride, boron, lead and benzene. The exposure pathways for CSG water are (1) water used for municipal purposes; (2) recreational water activities in rivers; (3) occupational exposures; (4) water extracted from contaminated aquifers; and (5) indirect exposure through the food chain. We recommend mapping of exposure pathways into communities in CSG regions to determine the potentially exposed populations in Queensland. Future efforts to monitor chemicals of concern and consolidate them into a central database will build the necessary capability to undertake a much needed environmental health impact assessment. PMID:24853090

  9. Evaluation of Chilled Methanol Processes for Acid Gas Removal

    Piña Dreyer, Manuel

    2011-01-01

    As the main goal achieved with this master thesis, a plant design was constructed for an acid gas removal process with methanol operating at low temperatures. First, a bibliographical research was made in terms of sour gas treatment; with special focus of physical absorption processes involving methanol as the solvent to achieve separation; such as Rectisol and Ifpexsol. The literature research was extended to thermodynamic data; compiling equilibrium values for binary systems between methano...

  10. Acid-resistant composite for reinforcing gas and oil wells

    Tarnavskiy, A.P.; Avilov, V.I.; Bayda, Yu.V.; Danyushevskiy, V.S.; Sitkov, B.P.; Zolotukhin, V.A.

    1982-01-01

    The acid-resistant composite for reinforcing gas and oil wells including ferromolybdenum slag, liquid glass and sodium fluosilicate is distinguished by the fact that in order to increase its setting periods in acid media with increased bed temperature to 80/sup 0/ C, it additionally contains potassium oleate with the following ratio of components (parts by weight): ferromolybdenum slag 100, liquid glass 99-100, sodium fluosilicate 5.5-10.0; potassium oleate 0.2-1.5.

  11. Hazard Ranking Methodology for Assessing Health Impacts of Unconventional Natural Gas Development and Production: The Maryland Case Study.

    Boyle, Meleah D; Payne-Sturges, Devon C; Sangaramoorthy, Thurka; Wilson, Sacoby; Nachman, Keeve E; Babik, Kelsey; Jenkins, Christian C; Trowell, Joshua; Milton, Donald K; Sapkota, Amir

    2016-01-01

    The recent growth of unconventional natural gas development and production (UNGDP) has outpaced research on the potential health impacts associated with the process. The Maryland Marcellus Shale Public Health Study was conducted to inform the Maryland Marcellus Shale Safe Drilling Initiative Advisory Commission, State legislators and the Governor about potential public health impacts associated with UNGDP so they could make an informed decision that considers the health and well-being of Marylanders. In this paper, we describe an impact assessment and hazard ranking methodology we used to assess the potential public health impacts for eight hazards associated with the UNGDP process. The hazard ranking included seven metrics: 1) presence of vulnerable populations (e.g. children under the age of 5, individuals over the age of 65, surface owners), 2) duration of exposure, 3) frequency of exposure, 4) likelihood of health effects, 5) magnitude/severity of health effects, 6) geographic extent, and 7) effectiveness of setbacks. Overall public health concern was determined by a color-coded ranking system (low, moderately high, and high) that was generated based on the overall sum of the scores for each hazard. We provide three illustrative examples of applying our methodology for air quality and health care infrastructure which were ranked as high concern and for water quality which was ranked moderately high concern. The hazard ranking was a valuable tool that allowed us to systematically evaluate each of the hazards and provide recommendations to minimize the hazards. PMID:26726918

  12. Hazard Ranking Methodology for Assessing Health Impacts of Unconventional Natural Gas Development and Production: The Maryland Case Study

    Sangaramoorthy, Thurka; Wilson, Sacoby; Nachman, Keeve E.; Babik, Kelsey; Jenkins, Christian C.; Trowell, Joshua; Milton, Donald K.; Sapkota, Amir

    2016-01-01

    The recent growth of unconventional natural gas development and production (UNGDP) has outpaced research on the potential health impacts associated with the process. The Maryland Marcellus Shale Public Health Study was conducted to inform the Maryland Marcellus Shale Safe Drilling Initiative Advisory Commission, State legislators and the Governor about potential public health impacts associated with UNGDP so they could make an informed decision that considers the health and well-being of Marylanders. In this paper, we describe an impact assessment and hazard ranking methodology we used to assess the potential public health impacts for eight hazards associated with the UNGDP process. The hazard ranking included seven metrics: 1) presence of vulnerable populations (e.g. children under the age of 5, individuals over the age of 65, surface owners), 2) duration of exposure, 3) frequency of exposure, 4) likelihood of health effects, 5) magnitude/severity of health effects, 6) geographic extent, and 7) effectiveness of setbacks. Overall public health concern was determined by a color-coded ranking system (low, moderately high, and high) that was generated based on the overall sum of the scores for each hazard. We provide three illustrative examples of applying our methodology for air quality and health care infrastructure which were ranked as high concern and for water quality which was ranked moderately high concern. The hazard ranking was a valuable tool that allowed us to systematically evaluate each of the hazards and provide recommendations to minimize the hazards. PMID:26726918

  13. Gas-Phase IR Spectroscopy of Deprotonated Amino Acids

    Oomens, J.; Steill, J. D.; Redlich, B.

    2009-01-01

    Gas-phase infrared multiple photon dissociation (IRMPD) spectra have been recorded for the conjugate bases of a series of amino acids (Asp, Cys, Glu, Phe, Set, Trp, Tyr). The spectra are dominated by strong symmetric and antisymmetric carboxylate stretching modes around 1300 and 1600 cm(-1), respect

  14. role of conjugated linoleic acid in the prevention of radiation hazard in male rats

    the objective of the present study was to examine the effect of conjugated linoleic acid (CLA) as a natural product in minimizing the radiation hazards. male rats were assigned to six groups each of 7 animals throughout six weeks, fed 1% CLA (wt/wt)added to commercial diet in the form of milk powder 182 g/kg diet. rats exposed to 6 Gy whole body gamma irradiation showed significant increase in total cholesterol (TC), low density lipoprotein cholesterol (LDL-C).triglycerides (TG), atherosclerosis index, total lipid (TL), phospholipids (ph-lipids), malondialdehyde (MDA), urea,creatinine, uric acid, calcium (Ca) and phosphorous levels associated with decrease in high density lipoprotein-cholesterol (HDL-C), activity of reduced glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), total antioxidant status, body weight, testes weight and testosterone both irradiated and non-irradiated milk powder administrated to irradiated rat groups minimized the radiation damage in the assayed parameters indicating its beneficial role as a promising antioxidant in scavenging free radicals and reactive oxygen species

  15. Hazardous gas production by alpha particles in solid organic transuranic waste matrices. 1998 annual progress report

    'This project uses fundamental radiation chemical techniques to elucidate the basic processes occurring in the heavy-ion radiolysis of solid hydrocarbon matrices such as polymers and organic resins that are associated with many of the transuranic waste deposits or the transportation of these radionuclides. The environmental management of mixed waste containing transuranic radionuclides is difficult because these nuclides are alpha particle emitters and the energy deposited by the alpha particles causes chemical transformations in the matrices accompanying the waste. Most radiolysis programs focus on conventional radiation such as gamma rays, but the chemical changes induced by alpha particles and other heavy ions are typically very different and product yields can vary by more than an order of magnitude. The objective of this research is to measure the production of gases, especially molecular hydrogen, produced in the proton, helium ion, and carbon ion radiolysis of selected solid organic matrices in order to obtain fundamental mechanistic information on the radiolytic decomposition of these materials. This knowledge can also be used to directly give reasonable estimates of explosive or flammability hazards in the storage or transport of transuranic wastes in order to enhance the safety of DOE sites. This report summarizes the work after eight months of a three-year project on determining the production of hazardous gases in transuranic waste. The first stage of the project was to design and build an assembly to irradiate solid organic matrices using accelerated ion beams. It is necessary to measure absolute radiolytic yields, and simulate some of the conditions found in the field. A window assembly was constructed allowing the beam to pass consecutively through a collimator, a vacuum exit window and into the solid sample. The beam is stopped in the sample and the entire end of the assembly is a Faraday cup. Integration of the collected current, in conjunction

  16. Modeling acid-gas generation from boiling chloride brines

    Zhang, Guoxiang; Spycher, Nicolas; Sonnenthal, Eric; Steefel, Carl

    2009-11-16

    This study investigates the generation of HCl and other acid gases from boiling calcium chloride dominated waters at atmospheric pressure, primarily using numerical modeling. The main focus of this investigation relates to the long-term geologic disposal of nuclear waste at Yucca Mountain, Nevada, where pore waters around waste-emplacement tunnels are expected to undergo boiling and evaporative concentration as a result of the heat released by spent nuclear fuel. Processes that are modeled include boiling of highly concentrated solutions, gas transport, and gas condensation accompanied by the dissociation of acid gases, causing low-pH condensate. Simple calculations are first carried out to evaluate condensate pH as a function of HCl gas fugacity and condensed water fraction for a vapor equilibrated with saturated calcium chloride brine at 50-150 C and 1 bar. The distillation of a calcium-chloride-dominated brine is then simulated with a reactive transport model using a brine composition representative of partially evaporated calcium-rich pore waters at Yucca Mountain. Results show a significant increase in boiling temperature from evaporative concentration, as well as low pH in condensates, particularly for dynamic systems where partial condensation takes place, which result in enrichment of HCl in condensates. These results are in qualitative agreement with experimental data from other studies. The combination of reactive transport with multicomponent brine chemistry to study evaporation, boiling, and the potential for acid gas generation at the proposed Yucca Mountain repository is seen as an improvement relative to previously applied simpler batch evaporation models. This approach allows the evaluation of thermal, hydrological, and chemical (THC) processes in a coupled manner, and modeling of settings much more relevant to actual field conditions than the distillation experiment considered. The actual and modeled distillation experiments do not represent

  17. Modeling acid-gas generation from boiling chloride brines

    This study investigates the generation of HCl and other acid gases from boiling calcium chloride dominated waters at atmospheric pressure, primarily using numerical modeling. The main focus of this investigation relates to the long-term geologic disposal of nuclear waste at Yucca Mountain, Nevada, where pore waters around waste-emplacement tunnels are expected to undergo boiling and evaporative concentration as a result of the heat released by spent nuclear fuel. Processes that are modeled include boiling of highly concentrated solutions, gas transport, and gas condensation accompanied by the dissociation of acid gases, causing low-pH condensate. Simple calculations are first carried out to evaluate condensate pH as a function of HCl gas fugacity and condensed water fraction for a vapor equilibrated with saturated calcium chloride brine at 50-150 C and 1 bar. The distillation of a calcium-chloride-dominated brine is then simulated with a reactive transport model using a brine composition representative of partially evaporated calcium-rich pore waters at Yucca Mountain. Results show a significant increase in boiling temperature from evaporative concentration, as well as low pH in condensates, particularly for dynamic systems where partial condensation takes place, which result in enrichment of HCl in condensates. These results are in qualitative agreement with experimental data from other studies. The combination of reactive transport with multicomponent brine chemistry to study evaporation, boiling, and the potential for acid gas generation at the proposed Yucca Mountain repository is seen as an improvement relative to previously applied simpler batch evaporation models. This approach allows the evaluation of thermal, hydrological, and chemical (THC) processes in a coupled manner, and modeling of settings much more relevant to actual field conditions than the distillation experiment considered. The actual and modeled distillation experiments do not represent

  18. Modeling acid-gas generation from boiling chloride brines

    Sonnenthal Eric

    2009-11-01

    Full Text Available Abstract Background This study investigates the generation of HCl and other acid gases from boiling calcium chloride dominated waters at atmospheric pressure, primarily using numerical modeling. The main focus of this investigation relates to the long-term geologic disposal of nuclear waste at Yucca Mountain, Nevada, where pore waters around waste-emplacement tunnels are expected to undergo boiling and evaporative concentration as a result of the heat released by spent nuclear fuel. Processes that are modeled include boiling of highly concentrated solutions, gas transport, and gas condensation accompanied by the dissociation of acid gases, causing low-pH condensate. Results Simple calculations are first carried out to evaluate condensate pH as a function of HCl gas fugacity and condensed water fraction for a vapor equilibrated with saturated calcium chloride brine at 50-150°C and 1 bar. The distillation of a calcium-chloride-dominated brine is then simulated with a reactive transport model using a brine composition representative of partially evaporated calcium-rich pore waters at Yucca Mountain. Results show a significant increase in boiling temperature from evaporative concentration, as well as low pH in condensates, particularly for dynamic systems where partial condensation takes place, which result in enrichment of HCl in condensates. These results are in qualitative agreement with experimental data from other studies. Conclusion The combination of reactive transport with multicomponent brine chemistry to study evaporation, boiling, and the potential for acid gas generation at the proposed Yucca Mountain repository is seen as an improvement relative to previously applied simpler batch evaporation models. This approach allows the evaluation of thermal, hydrological, and chemical (THC processes in a coupled manner, and modeling of settings much more relevant to actual field conditions than the distillation experiment considered. The actual

  19. The use of activated char for flue gas polishing in municipal and hazardous waste combustors

    Hartenstein, H.U.; Steinmueller, L.C.

    1996-10-01

    In the year of 1989/1990 stringent new emission requirements were introduced for municipal (MWC`s) and hazardous waste combustors (HWC`s) in Central Europe. These laws reducing not only the former emission values of most pollutants by a factor of 20 or more, also introduced new pollutants to be regulated such as dioxins (PCDD`s) and furans (PCDF`s). In order to meet these new laws a new generation of air pollution control (APC) equipment had to developed. Most of the new techniques are based on the use of some kind of activated carbon which allows for the low emission values required. This paper describes the ACR (activated char reactor) technology developed by the L. & C. Steinmutler GmbH, Gummersbach through its 100% subsidiary Hugo Petersen GmbH & Co. KG, Wiesbaden Germany. The ACR technology utilizes the excellent adsorption capabilities of activated char for a wide variety of air pollutants at the tail end and of the APC-train for flue gas polishing. The paper details the design as well as the removal capabilities of the technique. It outlines several full scale applications in Europe an provides data from various installations.

  20. Realtime Gas Emission Monitoring at Hazardous Sites Using a Distributed Point-Source Sensing Infrastructure.

    Manes, Gianfranco; Collodi, Giovanni; Gelpi, Leonardo; Fusco, Rosanna; Ricci, Giuseppe; Manes, Antonio; Passafiume, Marco

    2016-01-01

    This paper describes a distributed point-source monitoring platform for gas level and leakage detection in hazardous environments. The platform, based on a wireless sensor network (WSN) architecture, is organised into sub-networks to be positioned in the plant's critical areas; each sub-net includes a gateway unit wirelessly connected to the WSN nodes, hence providing an easily deployable, stand-alone infrastructure featuring a high degree of scalability and reconfigurability. Furthermore, the system provides automated calibration routines which can be accomplished by non-specialized maintenance operators without system reliability reduction issues. Internet connectivity is provided via TCP/IP over GPRS (Internet standard protocols over mobile networks) gateways at a one-minute sampling rate. Environmental and process data are forwarded to a remote server and made available to authenticated users through a user interface that provides data rendering in various formats and multi-sensor data fusion. The platform is able to provide real-time plant management with an effective; accurate tool for immediate warning in case of critical events. PMID:26805832

  1. Gas chromatography of alkylphosphonic and dialkyl phosphinic acids

    After carrying out an optimization study on the separation conditions for the TMSr- derivatives, of the hexyl-, cyclohexyl-, heptyl-, and octyl-phosphonic acids; dihexyl dicyclohexyl-, heptyl-, and octyl-phosphinic acids, and dioctyl phosphine oxide, their retention indices (I) at two temperatures and on the OV-1 and OV-17 stationary phase were determined. Correlations between I and molecular structure were established. Calibration factors of these compounds in the flame ionization detector were studied, and the results analyzed taking into account the variables affecting the quantitative results, These results were unbiased but they had a lower precision than that usually achievable in gas chromatography. (Author) 24 refs

  2. Gas hazard assessment in the touristic area of Levante Beach (Vulcano island, Italy)

    Carapezza, Maria Luisa; Di Piazza, Andrea; Gattuso, Alessandro; Ranaldi, Massimo; Sortino, Francesco; Tarchini, Luca

    2016-04-01

    Since the last eruption occurred at "La Fossa" in 1888-1890, Vulcano remained in a quiescence state characterized by an intense fumarolic activity. The main degassing manifestations are concentrated in La Fossa crater area (high temperature fumaroles) and in the area of Vulcano Porto, between Levante Beach and Faraglioni (medium-low temperature fumaroles). In addition the entire volcanic edifice of La Fossa, its base and the area of Vulcano Porto are characterized by en extensive soil CO2 diffuse degassing. In the last century episodic "crises" have occurred with increase of temperature, gas output and compositional changes of the crater fumaroles indicating an increase of the magmatic component in the discharged fluids. These episodic crises occurred in 1916-1924, in 1988-1993, in 1996 and in 2004-2006. During the period 1988-1990, the accumulation of CO2 in morphological depressions or excavation provoked the death for asphyxiation of two children in the area of Vulcano Porto and of some small animals at the base of the crater area. In April 2015, a child lost his senses while playing at Levante Beach; he was rescued by an air ambulance to the hospital of Lipari. According to the national chronicle (La Repubblica, 22 June 2015), doctors attributed the malaise to a high CO2 air concentration. Soon after this event the Major of Lipari installed at Levante Beach some panels informing tourists on gas hazard. In summer 2015 we performed a geochemical survey of the Levante Beach sector (onshore and offshore) and of the mud pool, estimating the diffuse and viscous gas flux and the air gas concentration in order to evaluate the degassing level. The total gas flux in the Levante Beach area, from 0.3 km2, has been estimated in 1 t/day of CO2 and 16,1 kg/day of H2S; values comparable with those of the 2009 and 2011 campaigns. In addition, a soil CO2 flux survey of the target area at La Fossa crater was performed, ascertaining that the degassing rate was within the range of

  3. Study on Cyclometalated Palladium-azo Complexes as Colorimetric Probes for Hazardous Gas in Water

    YU,Chun-Wei; LI,Shun-Hua; ZHENG,Hong; XU,Jin-Gou

    2007-01-01

    A synthesized cyclometalated palladium-azo complex was explored as a multifunctional probe for visual detection of SO2, H2S and NH3 in water. In acidic aqueous environment, the sensing solution underwent a sharp color change from poor violet to deep blue when titrated with Na2SO3 standard solution. But the color changed from poor violet to bright yellow when titrated with Na2S standard solution. In basic environment, the sensing solution rapidly changed to magenta when titrated by NH4Cl-NH3 standard buffer solution at high concentration. However, the color of sensing solution changed to blue when titrated by NH4Cl-NH3 standard buffer solution at low concentration although the pH was kept constant during the titration. Different species of these hazardous gases at environmentally relevant concentration levels were differentiated by independent optical signal outputs, and the interference from other inorganic ions commonly existing in water was very small.

  4. The risk early-warning of gas hazard in coal mine based on Rough Set-neural network

    TIAN Shui-cheng; WANG Li

    2007-01-01

    This article proposed the risk early-warning model of gas hazard based on Rough Set and neural network. The attribute quantity was reduced by Rough Set, the main characteristic attributes were withdrawn, the complexity of neural network system and the computing time was reduced, as well. Because of fault-tolerant ability, parallel processing ability, anti-jamming ability and processing non-linear problem ability of neural network system, the methods of Rough Set and neural network were combined. The examples research indicate: applying Rough Set and BP neural network to the gas hazard risk early-warning coal mines in coal mine, the BPNN structure is greatly simplified, the network computation quantity is reduced and the convergence rate is speed up.

  5. Potential geologic hazards and constraints for blocks in proposed Mid-Atlantic OCS oil and gas lease sale 49

    Hall, R. W., (Edited By); Ensminger, H. Robert

    1979-01-01

    Analysis of side-scan sonar, subbottom profiler, processed sparker, and fathometer data (approximately 5060 km) from the 136 blocks in the proposed Outer Continental Shelf Lease Sale 49 disclosed features that are potential geologic hazards to oil and gas exploration and development operations. These potential hazards are past mass sediment movement (slumping or sliding) in parts or all of 57 proposed lease sale blocks (27 of which are virtually covered by slumped materials), shallow gas deposits in three proposed lease sale blocks, and recent shallow faulting in one proposed lease sale block. Other features considered merely to be developmental constraints can be accommodated by existing standard design and engineering technology: erosion and scour, sand waves, filled channels, acoustically turbid zones (gassy sediments), lagoonal sediments, potentially unstable slopes (due to gradient), unidentified bottom objects, and a shipwreck.

  6. Gas and rock-bump hazard monitoring in the Polish mining

    ISAKOW Zbigniew; KRZYSTANEK Zdzistaw; TRENCZEK Stanislaw; WOJTAS Piotr

    2009-01-01

    Described the main environmental hazards occurring in Polish underground mines and their continuous growth in recent years as well as equipment and systems which were used for monitoring mine air parameters and geodynamic phenomena. The latest versions of environmental hazard monitoring systems, having a form of a compre- hensive set of underground and surface equipment, are presented and their functions characterized.

  7. Hazardous air pollutant emissions from gas-fired combustion sources: emissions and the effects of design and fuel type.

    England, G C; McGrath, T P; Gilmer, L; Seebold, J G; Lev-On, M; Hunt, T

    2001-01-01

    Air emissions from gas-fired combustion devices such as boilers, process heaters, gas turbines and stationary reciprocating engines contain hazardous air pollutants (HAPs) subjected to consideration under the federal clean air act (CAA). This work presents a recently completed major research project to develop an understanding of HAP emissions from gas-fired boilers and process heaters and new HAP emission factors based on field emission tests of gas-fired external combustion devices used in the petroleum industry. The effect of combustion system design and operating parameters on HAP emissions determined by both field and research tests are discussed. Data from field tests of gas-fired petroleum industry boilers and heaters generally show very low emission levels of organic HAPs. A comparison of the emission data for boilers and process heaters, including units with and without various forms of NOx emission controls, showed no significant difference in organic HAP emission characteristics due to process or burner design. This conclusion is also supported by the results of research tests with different burner designs. Based on field tests of units fired with natural gas and various petroleum industry process gases and research tests in which gas composition was intentionally varied, organic HAP emissions were not determined to be significantly affected by the gas composition. Research data indicate that elevated organic HAP emission levels are found only under extreme operating conditions (starved air or high excess air combustion) associated with poor combustion. PMID:11219701

  8. Hazardous air pollutant emissions from gas-fired combustion sources: emissions and the effects of design and fuel type

    Air emissions from gas-fired combustion devices such as boilers, process heaters, gas turbines and stationary reciprocating engines contain hazardous air pollutants (HAPs) subjected to consideration under the federal clean air act (CAA). This work presents a recently completed major research project to develop an understanding of HAP emissions from gas-fired boilers and process heaters and new HAP emission factors based on field emission tests of gas-fired external combustion devices used in the petroleum industry. The effect of combustion system design and operating parameters on HAP emissions determined by both field and research tests are discussed. Data from field tests of gas-fired petroleum industry boilers and heaters generally show very low emission levels of organic HAPs. A comparison of the emission data for boilers and process heaters, including units with and without various forms of NOx emission controls, showed no significant difference in organic HAP emission characteristics due to process or burner design. This conclusion is also supported by the results of research tests with different burner designs. Based on field tests of units fired with natural gas and various petroleum industry process gases and research tests in which gas composition was intentionally varied, organic HAP emissions were not determined to be significantly affected by the gas composition. Research data indicate that elevated organic HAP emission levels are found only under extreme operating conditions (starved air or high excess air combustion) associated with poor combustion. (author)

  9. Measurement of Gas-phase Acids in Diesel Exhaust

    Wentzell, J. J.; Liggio, J.; Li, S.; Vlasenko, A. L.; Staebler, R. M.; Brook, J.; Lu, G.; Poitras, M.; Chan, T.

    2012-12-01

    Gas-phase acids were measured using chemical ionization mass spectrometry (CIMS) as part of the Diesel Engine Emission Research Experiment (DEERE). The CIMS technique, utilizing acetate ion (CH3COO-) as a reagent ion, proved to be a rapid (measurements on the order of seconds) and sensitive (several counts/pptv) method of quantifying the acid emissions. Diluted diesel exhaust measurements were made from a Constant Volume Sampling dilution tunnel using a light duty (1.9L turbocharged Volkswagen Jetta TDI) diesel engine equipped with an OEM diesel oxidation catalyst and exhaust gas recirculation, mounted on an engine dynamometer. Acids measured included isocyanic, nitrous, nitric, propionic and sum of lactic and oxalic, as well as other unidentified compounds. Complimentary measurements of CO, CO2, Total Hydrocarbon (THC), and NOx, were also performed. Several engine modes (different engine rpm and torque outputs) at steady state were examined to determine their effect on acid emissions. Emission rates with respect to NOx and fuel based emission factors were determined. Measurements of HONO fuel emission factors agree well with real-world measurements within a traffic tunnel.1 The first estimate of isocyanic acid emission factors from a diesel engine is reported, and suggests that the emission of this highly toxic compound in diesel exhaust should not be ignored. 1. Kurtenbach, R., Becker, K. H., Gomes, J. A. G., Kleffmann, J.,Lorzer, J. C., Spittler, M., Wiesen, P., Ackermann, R., Geyer, A.,and Platt, U.: Investigations of emissions and heterogeneous formation of HONO in a road traffic tunnel, Atmos. Environ., 35, 3385-3394, doi:10.1016/S1352-2310(01)00138-8, 2001.

  10. Unknown plant de-construction hazard -- Toxic COS and CS2 gas from torch cutting of pipe

    An employee exhibited signs of illness after apparently inhaling fumes generated from a pipe that had been cut with a cutting torch. Identification and quantification of the hazardous air emission for reduction of risk via the Department of Energy Class B Investigation are described in this case study. The old hydrogen sulfide gas flare pipe in the heavy water plant of the Savannah River Site has been abandoned with one end open to atmosphere for almost twenty years. The pipe was being removed and cut into sections for disposal during an asbestos abatement project. It contained ash like corrosion deposits that smolder after torch cutting. Investigation revealed that burning of carbon and sulfur in the oxygen deficient atmosphere in the ash generated carbonyl sulfide (COS) and carbon disulfide (CS2) gas, which vented when the pipe was moved by the injured construction rigger. This is believed to be the first well documented exposure and response of a human to high concentration COS gas. Sulfur dioxide (SO2) gas is also generated during the cutting. SO2 is almost impossible to inhale and has apparently prevented a similar injury during the cutting. SO2 is almost impossible to inhale and has apparently prevented a similar injury during the many years of US and Canadian heavy water plant de-construction experience. Immediate water quench of the smoldering ash after each cut has eliminated the hazard of residual COS and CS2 gas. This previously unrecognized industrial hazard may be encountered by other chemical and petroleum industries during torch cutting of pipes that contain similar deposits of iron oxide, iron sulfate, sulfur and carbon

  11. Gas-Phase Fragmentation Analysis of Nitro-Fatty Acids

    Bonacci, Gustavo; Asciutto, Eliana K.; Woodcock, Steven R.; Salvatore, Sonia R.; Freeman, Bruce A.; Schopfer, Francisco J.

    2011-09-01

    Nitro-fatty acids are electrophilic signaling mediators formed in increased amounts during inflammation by nitric oxide and nitrite-dependent redox reactions. A more rigorous characterization of endogenously-generated species requires additional understanding of their gas-phase induced fragmentation. Thus, collision induced dissociation (CID) of nitroalkane and nitroalkene groups in fatty acids were studied in the negative ion mode to provide mass spectrometric tools for their structural characterization. Fragmentation of nitroalkanes occurred mainly through loss of the NO{2/-} anion or neutral loss of HNO2. The CID of nitroalkenes proceeds via a more complex cyclization, followed by fragmentation to nitrile and aldehyde products. Gas-phase fragmentation of nitroalkene functional groups with additional γ or δ unsaturation occurred through a multiple step cyclization reaction process, leading to 5 and 6 member ring heterocyclic products and carbon chain fragmentation. Cyclization products were not obtained during nitroalkane fragmentation, highlighting the role of double bond π electrons during NO{2/-} rearrangements, stabilization and heterocycle formation. The proposed structures, mechanisms and products of fragmentation are supported by analysis of 13C and 15N labeled parent molecules, 6 different nitroalkene positional isomers, 6 nitroalkane positional isomers, accurate mass determinations at high resolution and quantum mechanics calculations. Multiple key diagnostic ion fragments were obtained through this analysis, allowing for the precise placement of double bonds and sites of fatty acid nitration, thus supporting an ability to predict nitro positions in biological samples.

  12. Rapid reduction of lead leachate from hazardous fly ash using microwave treatment with acid combination.

    Chou, Chih-Mei; Wang, Li-Pang; Kao, Jimmy C M; Lin, Kae-Long; Chang, Yu-Min

    2016-02-01

    The novelty of this study is to rapidly reduce hazardous lead leachates from solid waste using microwave digestion treatment, which is an energy-saving and low greenhouse gas emission technology. The article presents the reduction of toxic characteristic leaching procedure-extractable lead concentration in the municipal solid waste incineration fly ash by the microwave digestion treatment in HNO3/H2SO4 combination, and focuses on the effects of treatment time and temperature. The results obtained from this study indicated a significant reduction efficiency of toxic characteristic leaching procedure-extractable lead concentration and showed sufficient reduction in leaching levels to render the treated fly ash safe in lead compound leaching characteristics. The reduction efficiency of toxic characteristic leaching procedure-extractable lead concentration can reach 98% in 15 minutes of treatment time. This is equivalent to the original toxic characteristic leaching procedure-extractable lead concentration of 46.2 mg L(-1) in raw fly ash being reduced down to less than 1.0 mg L(-1). Based on the experimental data obtained in this study, a useful correlation between reduction efficiency and treatment conditions is proposed. For engineering applications, the necessary minimum treatment time is solved using a graphic illustration method, by which the minimum treatment time (t(min)) is obtained if the desired reduction efficiency (η) and treatment temperature (T) are known. The effects of treatment time and temperature are discussed. Some problems caused by the microwave digestion treatment method are also delineated in this article. PMID:26526019

  13. Removal of the hazardous, volatile, and organic compound benzene from aqueous solution using phosphoric acid activated carbon from rice husk

    Yakout, Sobhy M

    2014-01-01

    Background Benzene is one of the most hazardous organic pollutants in groundwater. The removal of benzene from water is very important from a health point of view and for environmental protection. In this study, benzene adsorption kinetics was investigated using phosphoric acid activated carbon, prepared from rice husk. Results An initial rapid uptake of benzene was observed and became almost constant after 40 minutes of contact. Kinetic data was analyzed using pseudo first order, pseudo seco...

  14. A new chemical system solution for acid gas removal

    Seiler, M.; Rolker, J.; Witthaut, D.; Schulze, S. [Evonik Industries AG, Hanau (Germany); Buchholz, S. [Evonik Industries AG, Marl (Germany)

    2012-07-01

    An energy-efficient absorbent formulation fors eparating acid gases (e.g. CO{sub 2}, H2S) from gas streams such as natural gas, syngas or flue gas is important for a number of industrial applications. In many cases, a substantial share of their costs is driven by the operational expenditure (OPEX) of the CO{sub 2} separation unit. One possible strategy for reducing OPEX is the improvement of the absorbent performance. Although a number of absorbents for the separation of CO{sub 2} from gas streams exist, there is still a need to develop CO{sub 2} absorbents with an improved absorption performance, less corrosion and foaming, no nitrosamine formation, lower energy requirement and therefore less OPEX. This contribution aims at giving a brief state-of-the-art overview followed by an introduction and performance characterization of a new family of amine-based CO{sub 2} absorbents. High cyclic capacities in the range of 2.9 to 3.2 mol CO{sub 2} kg{sup -1} absorbent and low absorption enthalpies of about -30 kJ mol{sup -1} allow for significant savings in the regeneration energy of the new absorbent system. Calculations with the modified Kremser model indicate a reduction in the specific reboiler heat duty of 45 %. Moreover, the high-performance absorbents developed show much lower corrosion rates than state-of-the-art solutions that are currently employed. (orig.)

  15. Simulation of a Wet Sulfuric Acid Process (WSA for Utilization of Acid Gas Separated from Omani Natural Gas

    Ahmed Jawad Ali Al-Dallal

    2013-06-01

    Full Text Available In this study, a proposed process for the utilization of hydrogen sulphide separated with other gases from omani natural gas for the production of sulphuric acid by wet sulphuric acid process (WSA was studied. The processwas simulated at an acid gas feed flow of 5000 m3/hr using Aspen ONE- V7.1-HYSYS software. A sensitivity analysis was conducted to determine the optimum conditions for the operation of plant. This included primarily the threepacked bed reactors connected in series for the production of sulphur trioxidewhich represented the bottleneck of the process. The optimum feed temperature and catalyst bed volume for each reactor were estimated and then used in the simulation of the whole process for two cases namely 4 and 6 mole% SO2 stream fed to the first catalytic reactor. The 4mole% SO2 gaves the highest conversion (98% compared with 6 mole% SO2 (94.7%. A valuable quantity of heat was generated from the process. This excess heat could also be transformed into power in a turbine or used as a heating media in neighbouring process units.

  16. Analysis of radioactive mixed hazardous waste using derivatization gas chromatography/mass spectrometry, liquid chromatography, and liquid chromatography/mass spectrometry

    Six samples of core segments from Tank 101-SY were analyzed for chelators, chelator fragments, and several carboxylic acids by derivatization gas chromatography/mass spectrometry. The major components detected were ethylenediaminetetraacetic acid, nitroso-iminodiacetic acid, nitrilotriacetic acid, citric acid, succinic acid, and ethylenediaminetriacetic acid. The chelator of highest concentration was ethylenediaminetetraacetic acid in all six samples analyzed. Liquid chromatography was used to quantitate low molecular weight acids including oxalic, formic, glycolic, and acetic acids, which are present in the waste as acid salts. From 23 to 61% of the total organic carbon in the samples analyzed was accounted for by these acids

  17. Amine-oxide hybrid materials for acid gas separations

    Bollini, Praveen

    2011-01-01

    Organic-inorganic hybrid materials based on porous silica materials functionalized with amine-containing organic species are emerging as an important class of materials for the adsorptive separation of acid gases from dilute gas streams. In particular, these materials are being extensively studied for the adsorption of CO 2 from simulated flue gas streams, with an eye towards utilizing these materials as part of a post-combustion carbon capture process at large flue gas producing installations, such as coal-fired electricity-generating power plants. In this Application Article, the utilization of amine-modified organic-inorganic hybrid materials is discussed, focusing on important attributes of the materials, such as (i) CO 2 adsorption capacities, (ii) adsorption and desorption kinetics, and (iii) material stability, that will determine if these materials may one day be useful adsorbents in practical CO 2 capture applications. Specific research needs and limitations associated with the current body of work are identified. © 2011 The Royal Society of Chemistry.

  18. Potential geologic hazards and constraints for blocks in proposed North Atlantic OCS Oil and gas lease sale 52

    Carpenter, G.B.; Cardinell, A.P.; Francois, D.K.; Good, L.K.; Lewis, R.L.; Stiles, N.T.

    1982-01-01

    Analysis of high-resolution geophysical data collected over 540 blocks tentatively selected for leasing in proposed OCS Oil and Gas Lease Sale 52 (Georges Bank) revealed a number of potential geologic hazards to oil and gas exploration and development activities: evidence of mass movements and shallow gas deposits on the continental slope. No potential hazards were observed on the continental shelf or rise. Other geology-related problems, termed constraints because they pose a relatively low degree of risk and can be routinely dealt with by the use of existing technology have been observed on the continental shelf. Constraints identified in the proposed sale area are erosion, sand waves, filled channels and deep faults. Piston cores were collected for geotechnical analysis at selected locations on the continental slope in the proposed lease sale area. The core locations were selected to provide information on slope stability and to establish the general geotechnical properties of the sediments. Preliminary results of a testing program suggest that the surficial sediment cover is stable with respect to mass movement.

  19. Local permeability changes, passive degassing and related gas hazard at the Baia di Levante area (Vulcano island, Italy)

    Diliberto, Iole Serena; Cangemi, Marianna; Gagliano, Antonina Lisa; Inguaggiato, Salvatore; Madonia, Paolo; Pedone, Maria; Fabio Pisciotta, Antonino

    2016-04-01

    Vulcano, the southernmost island of the Aeolian archipelago (Italy), is presently characterized by active fumarolic fields located along the rim of La Fossa cone and the shoreline of the Baia di Levante beach, in the northern portion of the island.The Baia di Levante fumarolic vents are fed by a shallow hydrothermal aquifer heated by magmatic gases rising from the deep down, with a spatial distribution strongly affected by the local fracture network. These fractures are the expression of a deformation field, dominated by a northward motion to Lipari, abruptly decaying to the Vulcanello peninsula, immediately northward of the Baia di Levante beach. Variable rates of fluid transfer to the surface, following permeability changes affecting the fracture network are among the results of stress field variations over time which induce fluctuations in the pressure state of the hydrothermal system. Under these conditions, increments in hydrothermal gas flow, able to cause an increase of gas hazard, could be determined by a rearrangement of the shallow permeability distribution induced by changes in the deformation field. In this case not associated to any variation in the volcanic activity state. Since 2009 an huge gas flow increment has been noticed in some undersea vents of the Baia di Levante area, leading to increase of gas hazard in their immediate surroundings. On the contrary, the acquired data from the INGV volcanic surveillance program didn't suggest any correlated increase of the magmatic fluid component in the degassing activity.In July 2015, we carried out multi-parametric geochemical surveys in this area, based on direct (thermocouple) and indirect (thermal infrared camera and pyrometer) soil temperature, soil CO2 flux, atmospheric concentration of CO2 and H2S measurements at low elevation (one meter a.s.l.). The chemical and isotopic composition of low temperature fumarole gases was determined too.The comparison of the new data with previous surveys carried out

  20. Acid gas injection: Another approach of acid gas treatment%酸气回注——酸气处理的另一途径

    John J.Carroll; Shouxi Wang; 汤林

    2009-01-01

    目前在北美,很多生产富含硫化氢和二氧化碳的天然气公司均采用一种新技术处理其废气,该废气的主要成分为硫化氢和二氧化碳,故称为"酸气".这种处理酸气的过程被称为酸气回注系统,其过程主要涉及酸气压缩、输送以及注入地下储存层.这种酸气回注技术解决了地面硫的回收和二氧化碳排放对空气污染的问题,已经逐渐成为一种切实可行的酸气处理方法.为此,针对不同回注酸气流的组成,分别从回注酸气的地层、回注酸气的管道、酸气流体相包络曲线、酸气压缩机、酸气含水量和压缩机操作过程中的注意事项等方面全面介绍了酸气回注技术及酸气回注系统的设计要点.该方法是酸气处理的另一条途经.%At present, many sour natural gas producers in North America adopt a new technology to deal with the waste gas, so-called acid gas, which mainly contains H_2S and CO_2. The acid gas treatment technology is also called acid gas injection system, the process of which involves the compression, transportation, and subsurface injection of acid gas stream. This technology has become a feasible and practical method of acid gas treatment which has solved the problems of sulfur recovery and carbon dioxide emission. According to different compositions of acid gas stream, acid gas injection design requires many sides of considerations including the underground stratum and pipes of acid flooding, the envelop curve of acid gas stream, the acid gas compressor, the water content in acid gas, and the operation process of the compressor, etc. This new technology has been proved to be another good approach of dealing with acid gas in fields.

  1. Source Mechanism, Stress Triggering, and Hazard Analysis of Induced Seismicity in Oil/Gas Fields in Oman and Kuwait

    Gu, C.; Toksoz, M. N.; Ding, M.; Al-Enezi, A.; Al-Jeri, F.; Meng, C.

    2015-12-01

    Induced seismicity has drawn new attentions in both academia and industry in recent years as the increasing seismic activity in the regions of oil/gas fields due to fluid injection/extraction and hydraulic fracturing. Source mechanism and triggering stress of these induced earthquakes are of great importance for understanding their causes and the physics of the seismic processes in reservoirs. Previous research on the analysis of induced seismic events in conventional oil/gas fields assumed a double couple (DC) source mechanism. The induced seismic data in this study are from both Oman and Kuwait. For the Oman data, the induced seismicity is monitored by both surface network (0oil/gas field. The data used in the study consist of 800 events located by the surface network and 2000 events from the downhole network. For the Kuwait data a surface network is used to collect the local seismic data (0oil/gas fields from year 1999 to 2007 for Oman, and from year 2006 to 2015 for Kuwait. In addition, the local hazard corresponding to the induced seismicity in these oil/gas fields is assessed and compared to ground motion prediction due to large (M>5.0) regional tectonic earthquakes.

  2. [Determination of docosahexaenoic acid in milk powder by gas chromatography using acid hydrolysis].

    Shao, Shiping; Xiang, Dapeng; Li, Shuang; Xi, Xinglin; Chen, Wenrui

    2015-11-01

    A method to determine docosahexenoic acid (DHA) in milk powder by gas chromatography was established. The milk powder samples were hydrolyzed with hydrochloric acid, extracted to get total fatty acids by Soxhlet extractor, then esterified with potassium hydroxide methanol solution to form methyl esters, and treated with sodium hydrogen sulfate. The optimal experiment conditions were obtained from orthogonal experiment L9(3(3)) which performed with three factors and three levels, and it requires the reaction performed with 1 mol/L potassium hydroxide solution at 25 degrees C for 5 min. The derivative treated with sodium hydrogen sulfate was separated on a column of SP-2560 (100 m x 0.25 mm x 0.20 μm), and determined in 55 min by temperature programming-gas chromatography. Good linearity was obtained in the range 5.0-300 mg/L with the correlation coefficient of 0.999 9. The relative standard deviations (RSDs) were 3.4%, 1.2% and 1.1% for the seven repeated experiments of 10, 50 and 100 mg/L of DHA, respectively. The limit of detection was 2 mg/kg, and the recoveries of DHA were in the range of 90.4%-93.5%. The results are satisfactory through the tests of practical samples. PMID:26939370

  3. Effects of gas atmospheres on poly(lactic acid) film in acrylic acid plasma treatment

    Plasma polymerized acrylic acid (AA) coatings were deposited on poly(lactic acid) (PLA) films in various gas atmospheres during the pre-treatment of PLA and the deposition of AA, respectively. Therefore, this work was twofold: the argon pretreated PLA films followed by a deposition in argon were investigated against the mixture of argon and oxygen pretreated ones under the same deposition conditions; the plasma deposition of AA operating in different atmospheres (argon, oxygen and nitrogen) was employed to modify the pretreated PLA in oxygen. Chemical and physical changes on the plasma-treated surfaces were examined using contact angle, X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FE-SEM) and attenuated total reflection infrared (ATR-FTIR) analysis. The results showed that the discharge gas can have a significant influence on the chemical composition of the PLA surfaces: oxygen plasmas introduced oxygen-containing groups in company with surface etching in pretreatment and deposition, while argon discharges was able to achieve much better hydrophilic behavior and high retention ratio of poly(acrylic acid) (PAA) coating before and after washing in water.

  4. Effects of gas atmospheres on poly(lactic acid) film in acrylic acid plasma treatment

    Zhao, Yun, E-mail: yun.zhaotju@yahoo.com [Dipartimento di Scienza Applicata e Tecnologia, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Turin (Italy); Fina, Alberto [Dipartimento di Scienza Applicata e Tecnologia, Politecnico di Torino – sede di Alessandria, V. T. Michel 5, 15121 Alessandria (Italy); Venturello, Alberto; Geobaldo, Francesco [Dipartimento di Scienza Applicata e Tecnologia, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Turin (Italy)

    2013-10-15

    Plasma polymerized acrylic acid (AA) coatings were deposited on poly(lactic acid) (PLA) films in various gas atmospheres during the pre-treatment of PLA and the deposition of AA, respectively. Therefore, this work was twofold: the argon pretreated PLA films followed by a deposition in argon were investigated against the mixture of argon and oxygen pretreated ones under the same deposition conditions; the plasma deposition of AA operating in different atmospheres (argon, oxygen and nitrogen) was employed to modify the pretreated PLA in oxygen. Chemical and physical changes on the plasma-treated surfaces were examined using contact angle, X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FE-SEM) and attenuated total reflection infrared (ATR-FTIR) analysis. The results showed that the discharge gas can have a significant influence on the chemical composition of the PLA surfaces: oxygen plasmas introduced oxygen-containing groups in company with surface etching in pretreatment and deposition, while argon discharges was able to achieve much better hydrophilic behavior and high retention ratio of poly(acrylic acid) (PAA) coating before and after washing in water.

  5. Comparative acute freshwater hazard assessment and preliminary PNEC development for eight fluorinated acids.

    Hoke, Robert A; Bouchelle, Laurie D; Ferrell, Barbra D; Buck, Robert C

    2012-05-01

    Short-term 48, 72 and 96-h aquatic toxicity tests were conducted to evaluate the acute toxicity of eight fluorinated acids to the cladoceran, Daphnia magna, the green alga, Pseudokirchneriella subcapitata, and the rainbow trout, Oncorhynchus mykiss or the fathead minnow, Pimephales promelas. The eight fluorinated acids studied were tridecafluorohexyl ethanoic acid (6:2 FTCA), heptadecafluorooctyl ethanoic acid (8:2 FTCA), 2H-dodecafluoro-2-octenoic acid (6:2 FTUCA), 2H-hexadecafluoro-2-decenoic acid (8:2 FTUCA), 2H,2H,3H,3H-undecafluoro octanoic acid (5:3 acid), 2H,2H,3H,3H-pentadecafluoro decanoic acid (7:3 acid), n-perfluoropentanoic acid (PFPeA) and n-perfluorodecanoic acid (PFDA). The results of the acute toxicity tests conducted during this study suggest that the polyfluorinated acids, 8:2 FTCA, 8:2 FTUCA, 6:2 FTCA, 6:2 FTUCA, 7:3 acid and 5:3 acid, and the perfluorinated acids PFPeA and PFDA, are generally of low to medium concern based on evaluation of their acute freshwater toxicity (EC/LC50s typically between 1 and >100 mg L(-1)) using the USEPA TSCA aquatic toxicity evaluation paradigm. For the polyfluorinated acids, aquatic toxicity generally decreased as the number of fluorinated carbons decreased and as the overall carbon chain length decreased from 12 to 8. Acute aquatic toxicity of the 5 and 10 carbon perfluorocarboxylic acids (EC/LC50s between 10.6 and >100 mg L(-1)) was greater or similar to that of the 6-9 carbon perfluorocarboxylic acids (EC/LC50s>96.5 mg L(-1)). This study also provides the first report of the acute aquatic toxicity of the 5:3 acid (EC/LC50s of 22.5 to >103 mg L(-1)) which demonstrated less aquatic toxicity than the 7:3 acid (EC/LC50s of 0.4-32 mg L(-1)). The cladoceran, D. magna and the green alga, P. subcapitata had generally similar EC50 values for a given substance while fish were typically equally or less sensitive with the exception that PFPeA was most toxic to fish. Predicted no-effect concentrations (PNECs) were

  6. Reactive Transport Modeling of Acid Gas Generation and Condensation

    Pulvirenti et al. (2004) recently conducted a laboratory evaporation/condensation experiment on a synthetic solution of primarily calcium chloride. This solution represents one potential type of evaporated pore water at Yucca Mountain, Nevada, a site proposed for geologic storage of high-level nuclear waste. These authors reported that boiling this solution to near dryness (a concentration factor >75,000 relative to actual pore waters) leads to the generation of acid condensate (pH 4.5) presumably due to volatilization of HCl (and minor HF and/or HNO3). To investigate the various processes taking place, including boiling, gas transport, and condensation, their experiment was simulated by modifying an existing multicomponent and multiphase reactive transport code (TOUGHREACT). This code was extended with a Pitzer ion-interaction model to deal with high ionic strength. The model of the experiment was set-up to capture the observed increase in boiling temperature (143 C at ∼1 bar) resulting from high concentrations of dissolved salts (up to 8 m CaCl2). The computed HCI fugacity (∼ 10-4 bars) generated by boiling under these conditions is not sufficient to lower the pH of the condensate (cooled to 80 and 25 C) down to observed values unless the H2O mass fraction in gas is reduced below ∼10%. This is because the condensate becomes progressively diluted by H2O gas condensation. However, when the system is modeled to remove water vapor, the computed pH of instantaneous condensates decreases to ∼1.7, consistent with the experiment (Figure 1). The results also show that the HCl fugacity increases, and calcite, gypsum, sylvite, halite, MgCl24H2O and CaCl2 precipitate sequentially with increasing concentration factors

  7. The Role of Deposition in Limiting the Hazard Extent of Dense-Gas Plumes

    Dillon, M B

    2008-01-29

    Accidents involving release of large (multi-ton) quantities of toxic industrial chemicals often yield far fewer fatalities and causalities than standard, widely-used assessment and emergency response models predict. While recent work has suggested that models should incorporate the protection provided by buildings, more refined health effect methodologies, and more detailed consideration of the release process; investigations into the role of deposition onto outdoor surfaces has been lacking. In this paper, we examine the conditions under which dry deposition may significantly reduce the extent of the downwind hazard zone. We provide theoretical arguments that in congested environments (e.g. suburbs, forests), deposition to vertical surfaces (such as building walls) may play a significant role in reducing the hazard zone extent--particularly under low-wind, stable atmospheric conditions which are often considered to be the worst-case scenario for these types of releases. Our analysis suggests that in these urban or suburban environments, the amount of toxic chemicals lost to earth's surface is typically a small fraction of overall depositional losses. For isothermal gases such as chlorine, the degree to which the chemicals stick to (or react with) surfaces (i.e. surface resistance) is demonstrated to be a key parameter controlling hazard extent (the maximum distance from the release at which hazards to human health are expected). This analysis does not consider the depositional effects associated with particulate matter or gases that undergo significant thermal change in the atmosphere. While no controlled experiments were available to validate our hypothesis, our analysis results are qualitatively consistent with the observed downwind extent of vegetation damage in two chlorine accidents.

  8. Source Mechanism, Stress Triggering, and Hazard Analysis of Induced Seismicity in Oil/Gas Fields in Oman and Kuwait

    Gu, C.; Toksoz, M. N.; Ding, M.; Al-Enezi, A.; Al-Jeri, F.; Meng, C.

    2015-12-01

    Induced seismicity has drawn new attentions in both academia and industry in recent years as the increasing seismic activity in the regions of oil/gas fields due to fluid injection/extraction and hydraulic fracturing. Source mechanism and triggering stress of these induced earthquakes are of great importance for understanding their causes and the physics of the seismic processes in reservoirs. Previous research on the analysis of induced seismic events in conventional oil/gas fields assumed a double couple (DC) source mechanism. The induced seismic data in this study are from both Oman and Kuwait. For the Oman data, the induced seismicity is monitored by both surface network (0ratio of the data makes it possible to obtain the source mechanisms and triggering stress. We determine the full moment tensor of the induced seismicity data, based on a full-waveform inversion method (Song and Toksöz, 2011). With the full moment tensor inversion results, Coulomb stress is calculated to investigate the triggering features of the induced seismicity data. Our results show a detailed evolution of 3D triggering stress in oil/gas fields from year 1999 to 2007 for Oman, and from year 2006 to 2015 for Kuwait. In addition, the local hazard corresponding to the induced seismicity in these oil/gas fields is assessed and compared to ground motion prediction due to large (M>5.0) regional tectonic earthquakes.

  9. Rapid and selective detection of acetone using hierarchical ZnO gas sensor for hazardous odor markers application

    Highlights: • ZnO spheres fabricated via solvothermal method are with (0 0 2) polar facet exposed. • Response time of ZnO sensor for detecting 100 ppm acetone is as short as 3 s. • Ra/Rg toward 100 ppm acetone is 33 when operated at 230 °C. • ZnO sensor exhibits good selectivity against other toxic gases and water vapor. • Porous structure and exposure of polar facet contribute to good sensing properties. - Abstract: Hierarchical nanostructured ZnO dandelion-like spheres were synthesized via solvothermal reaction at 200 °C for 4 h. The products were pure hexagonal ZnO with large exposure of (0 0 2) polar facet. Side-heating gas sensor based on hierarchical ZnO spheres was prepared to evaluate the acetone gas sensing properties. The detection limit to acetone for the ZnO sensor is 0.25 ppm. The response (Ra/Rg) toward 100 ppm acetone was 33 operated at 230 °C and the response time was as short as 3 s. The sensor exhibited remarkable acetone selectivity with negligible response toward other hazardous gases and water vapor. The high proportion of electron depletion region and oxygen vacancies contributed to high gas response sensitivity. The hollow and porous structure of dandelion-like ZnO spheres facilitated the diffusion of gas molecules, leading to a rapid response speed. The largely exposed (0 0 2) polar facets could adsorb acetone gas molecules easily and efficiently, resulting in a rapid response speed and good selectivity of hierarchical ZnO spheres gas sensor at low operating temperature

  10. Rapid and selective detection of acetone using hierarchical ZnO gas sensor for hazardous odor markers application

    Jia, Qianqian; Ji, Huiming, E-mail: jihuiming@tju.edu.cn; Zhang, Ying; Chen, Yalu; Sun, Xiaohong, E-mail: sunxh@tju.edu.cn; Jin, Zhengguo

    2014-07-15

    Highlights: • ZnO spheres fabricated via solvothermal method are with (0 0 2) polar facet exposed. • Response time of ZnO sensor for detecting 100 ppm acetone is as short as 3 s. • R{sub a}/R{sub g} toward 100 ppm acetone is 33 when operated at 230 °C. • ZnO sensor exhibits good selectivity against other toxic gases and water vapor. • Porous structure and exposure of polar facet contribute to good sensing properties. - Abstract: Hierarchical nanostructured ZnO dandelion-like spheres were synthesized via solvothermal reaction at 200 °C for 4 h. The products were pure hexagonal ZnO with large exposure of (0 0 2) polar facet. Side-heating gas sensor based on hierarchical ZnO spheres was prepared to evaluate the acetone gas sensing properties. The detection limit to acetone for the ZnO sensor is 0.25 ppm. The response (R{sub a}/R{sub g}) toward 100 ppm acetone was 33 operated at 230 °C and the response time was as short as 3 s. The sensor exhibited remarkable acetone selectivity with negligible response toward other hazardous gases and water vapor. The high proportion of electron depletion region and oxygen vacancies contributed to high gas response sensitivity. The hollow and porous structure of dandelion-like ZnO spheres facilitated the diffusion of gas molecules, leading to a rapid response speed. The largely exposed (0 0 2) polar facets could adsorb acetone gas molecules easily and efficiently, resulting in a rapid response speed and good selectivity of hierarchical ZnO spheres gas sensor at low operating temperature.

  11. Identification of Cyclopentenyl Fatty Acids by Gas Liquid Chromatography and Mass Spectrometry

    Shukla, V. K. S.; Abdel-Moety, E. M.; Larsen, Elfinn;

    1979-01-01

    The straight chain fatty acids and the cyclopentenyl fatty acids present in the lipids of Hydnocarpus wightiana seeds were separated as their pyrrolidides by means of gas chromatography. A gas chromatography-mass spectrometry system confirmed the complete separation and permitted the identification...

  12. Methods for upgrading of a fuel gas and succinic acid production

    2014-01-01

    The present invention provides methods of upgrading of a CO2-containing fuel gas comprising the use of anaerobic succinic acid-producing microorganisms. Thus, the present invention provides a method for simultaneous upgrading of a CO2-containing fuel gas and biosuccinic acid production....

  13. Effect of gas emissions from Tianchi volcano (NE China) on environment and its potential volcanic hazards

    2006-01-01

    The Tianchi volcano in the Changbai Mountains is located on the boundary between China and North Korea. There are many times of eruptions of the Tianchi volcano during the Holocene. One of its large eruptions occurred around 1000 years ago dated by 14C method and historical records. Composition of products of the largest Tianchi volcanic eruption studied is characterized by comenditic Plinian fallout and unwelded ignimbrite, which are mainly distributed in China and North Korea. Caldera is about 4.4 km long and 3.4 km wide, which had filled with water (e.g. Tianchi Lake). The Tianchi volcanic cone is about 2700 m high above sea level. The Tianchi Lake is located on the summit of the volcanic cone, that is also highest peak of the Changbai Mountains in northeastern China. This study analyzed Cl, F, S and H2O concentrations of melt inclusions in the phenocryst minerals (anorthoclase and quartz) and co-existing matrix glasses using the electron microprobe and estimated environmental effect of Tianchi volcanic gases. The authors proposed a new method to evaluate future eruption of active volcano and estimate potential volcanic hazards based on contents of volatile emissions. Using this method, we made a perspective of future volcanic hazard in this region.

  14. Proceedings of the 1. international acid gas injection symposium 2009 Canada

    Developed in Alberta, acid gas injection is an innovative technology that is now used throughout the world as a means of reducing emissions and enhancing oil recovery. This international symposium provided a forum for researchers, reservoir engineers, industry members and other stakeholders to discuss recent advances in acid gas technology. Challenges associated with the implementation and operation of acid gas injection systems were discussed. Pilot projects and demonstration programs related to acid gas injection into aquifers and other geologic structures were reviewed. Mathematical models and simulation studies for predicting acid gas behaviour were also presented. The symposium also discussed various case studies of projects currently being conducted in China. All 32 presentations from this symposium have been catalogued separately for inclusion in this database

  15. The use of activated char for flue gas polishing in municipal and hazardous waste combustors

    Hartenstein, H.U. [L & C Steinmueller GmbH, Gummersbach (Germany)

    1996-12-31

    During the late 1980`s and the early 1990`s legislation on emissions from waste combustors were tightened drastically. Also emission limits on new pollutants like dioxins and furans were introduced. Since the flue gas cleaning equipment commonly used before was not designed to meet these emission limits, new technologies had to be developed. Most of these new technologies rely on the use of activated carbon or char for the adsorption of the pollutants. Due to the fact that the amount of activated char used is directly proportional to the mass flow rate of pollutants entering the adsorber, the bulk part of the pollutants has been removed in the preceding gas cleaning stages. Thus the activated char adsorption reactor is employed as a flue gas polishing stage at the end of the APC-train.

  16. Perfluorosulfonic acid membrane catalysts for optical sensing of anhydrides in the gas phase.

    Ayyadurai, Subasri M; Worrall, Adam D; Bernstein, Jonathan A; Angelopoulos, Anastasios P

    2010-07-15

    Continuous, on-site monitoring of personal exposure levels to occupational chemical hazards in ambient air is a long-standing analytical challenge. Such monitoring is required to institute appropriate health measures but is often limited by the time delays associated with batch air sampling and the need for off-site instrumental analyses. In this work, we report on the first attempt to use the catalytic properties of perfluorosulfonic acid (PSA) membranes to obtain a rapid, selective, and highly sensitive optical response to trimellitic anhydride (TMA) in the gas phase for portable sensor device application. TMA is used as starting material for various organic products and is recognized to be an extremely toxic agent by the National Institute for Occupational Safety and Health (NIOSH). Resorcinol dye is shown to become immobilized in PSA membranes and diffusionally constrain an orange brown product that results from acid-catalyzed reaction with more rapidly diffusing TMA molecules. FTIR, UV/vis, reaction selectivity to TMA versus trimellitic acid (TMLA), and homogeneous synthesis are used to infer 5,7- dihydroxyanthraquinone-2-carboxylic acid as the acylation product of the reaction. The color response has a sensitivity to at least 3 parts per billion (ppb) TMA exposure and, in addition to TMLA, excludes maleic anhydride (MA) and phthalic anhydride (PA). Solvent extraction at long times is used to determine that the resorcinol extinction coefficient in 1100 EW PSA membrane has a value of 1210 m(2)/g at 271.01 nm versus a value of 2010 m(2)/g at 275.22 nm in 50 vol% ethanol/water solution. The hypsochromic wavelength shift and reduced extinction coefficient suggest that the polar perfluorosulfonic acid groups in the membrane provide the thermodynamic driving force for diffusion and immobilization. At a resorcinol concentration of 0.376 g/L in the membrane, a partition coefficient of nearly unity is obtained between the membrane and solution concentrations and a

  17. Report: Proceedings of the Hedberg Research Conference 'Gas Hydrates : Energy resource potential and associated geologic hazards'

    Veerayya, M.

    -1 NOTES 651 The crisis in Kashmir valley like tsunami is of a delayed reaction. Difficulty seems communication between SASE (Snow and Avalanche Studies Establishment) and the users i.e. army and local population. All avalanche-prone spots are now...), was convened in Vancouver, British Columbia. Canada, from 12-16 September, 2004. Dr. Tim Collett. U.S. Geological Survey, Denver, CO, USA and Dr. A Johnson (Hydrate Energy International, New Orleans, LA, USA) have organized this conference. Natural gas hydrate...

  18. Gas hazard assessment at the Monticchio Mt. Vulture, a volcano in Southern Italy

    Caracausi, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Nuccio, P. M.; Dipartimento Chimica e Fisica della Terra e Applicazioni, Universita` di Palermo, Via Archirafi 36, 90100, Palermo, Italy; Favara, R.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Nicolosi, M.; Dipartimento Chimica e Fisica della Terra e Applicazioni, Universita` di Palermo, Via Archirafi 36, 90100, Palermo, Italy; Paternoster, M.; Dipartimento Scienze Geologiche, Università della Basilicata.

    2009-01-01

    Geochemical investigations have shown that there is a considerable inflow of gas into both crater lakes of Monticchio, Southern Italy. These lakes are located in two maars that formed 140 000 years ago during Mt. Vulture volcano s last eruptive activity. Isotopic analyses suggest that CO2 and helium are of magmatic origin; the latter displays 3He ⁄ 4He isotope ratios similar to those measured in olivines of the maar ejecta. In spite of the fact that the amount of dissolved gases in the wat...

  19. Gas hazard assessment at the Monticchio crater lakes of Mt. Vulture, a volcano in Southern Italy

    Caracausi, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Nuccio, P. M.; Dipartimento CFTA, Universita` di Palermo, Palermo, Italy.; R. Favara; Nicolosi, M.; Dipartimento CFTA, Universita` di Palermo, Palermo, Italy.; Paternoster, M.; Dipartimento Scienze Geologiche, Università della Basilicata.

    2008-01-01

    Geochemical investigations have shown that there is a considerable inflow of gas into both crater lakes of Monticchio, Southern Italy. These lakes are located in two maars that formed 140,000 years ago during Mt. Vulture volcano’s last eruptive activity. Isotopic analyses suggest that CO2 and helium are of magmatic origin; the latter displays 3He/4He isotope ratios similar to those measured in olivines of the maar ejecta. In spite of the fact that the amount of dissolved gases in the water is...

  20. Assessment of Volatile Organic Compound and Hazardous Air Pollutant Emissions from Oil and Natural Gas Well Pads using Mobile Remote and On-site Direct Measurements

    Emissions of volatile organic compounds (VOC) and hazardous air pollutants (HAP) from oil and natural gas production were investigated using direct measurements of component-level emissions on well pads in the Denver-Julesburg (DJ) Basin and remote measurements of production pad-...

  1. Environmental assessment of indoor radon gas exposure health hazards and some of its public risks

    This study examine the relationship between indoor radon gas exposure and the cancer risk and housing characteristics in lung cancer risk houses (CRH) compared to non lung cancer risk houses (NCRH). Mean radon concentrations measured by active method were significantly higher among CRH compared to NCRH, 9:93 pCi/L versus 4.56 pCi/L, respectively. There was no statistically significant diurnal variation as regards radon levels in all examined houses. Indoor radon concentrations show statistically significance in houses with bad ventilation (low air change rate) compared to houses with good ventilation (high air change rate). Houses with floor material of tiles, had statistically significant higher radon concentrations. Neither finishing wall material nor indoor gas source shows statistically significance as regard radon levels. Radon levels > 4 pCi/L (US EPA action level) were statistically significance higher in bed rooms compared levels in living rooms. High radon concentrations were reported in lung cane risk houses and in houses with bad ventilation

  2. Shale gas, a hazardous exploitation; Gaz de schiste, une exploitation a risque

    Maincent, G.

    2011-04-15

    In march 2010 three authorizations to search for shale gases were delivered in France in the regions of Montelimar, Nant and Villeneuve-de-Berg. A general public outcry has led the government to freeze the projects till a complete assessment of the impact on the environment is made. The fears of the public are based on the feedback experience in the Usa where some underground waters were polluted. The source of pollution is twofold: first the additives used in the injected fluids (methanol as an anti-microbic agent, hydrochloric acid to dissolve natural cements or glycol ethylene as a deposit inhibitor) and secondly metal particles of copper, zinc or lead trapped in the clay layers and released by the injection of the fluids. It appears also that the injection of high pressure fluids near a crack can induce earth tremors by reactivating the crack. (A.C.)

  3. The application of thermospray LC/MS to the analysis of small organic acids in mixed hazardous wastes

    The Hanford site was built by the Army Corps of Engineers and the Du Pont Corporation in 1943 to produce plutonium for nuclear weapons in support of World War II. The facility was very successful; within two years after its conception, Hanford had supplied the plutonium used for the bomb dropped on Nagasaki in World War II. Plutonium production continued after the war until January 1987 when the last product reactor ceased operation at the Hanford site. Nine production reactors and five reprocessing facilities operated at the Hanford site to support that mission. These operations created a large quantity of radioactive wastes, much of which was and continues to be stored in underground storage tanks. There are 177 high-level waste storage tanks at Hanford. Of these, 23 tanks are being watched closely because of the possibility that flammable gas mixtures are being produced from the mixed waste contained in the storage tanks. One tank in particular, Tank 241-SY-101, has exhibited episodic release of flammable gas mixtures since its initial filing in the late 1970s. Studies of simulated waste mixtures (SWM) have indicated that the gas generation and retention are influenced by chelator concentration. It was postulated that the chelators form hydrophobic surfaces on solids in the SWM. These hydrophobic surfaces are more conducive to bubble attachment, which leads to flotation of the solids and eventually crust formation. The presence of chelators becomes very important for the understanding of crust formation and gas release. Among the degradation products of the chelators are a number of small organic acids, some of which may be linked to the production of flammable gases such as hydrogen and which also possess chelating properties. As a result, the authors have analyzed actual waste samples from Tank 101-SY for small organic acids

  4. Effect of dimethylamine on the gas phase sulfuric acid concentration measured by Chemical Ionization Mass Spectrometry

    L. Rondo; Flagan, R. C.

    2016-01-01

    Sulfuric acid is widely recognized as a very important substance driving atmospheric aerosol nucleation. Based on quantum chemical calculations it has been suggested that the quantitative detection of gas phase sulfuric acid (H_2SO_4) by use of Chemical Ionization Mass Spectrometry (CIMS) could be biased in the presence of gas phase amines such as dimethylamine (DMA). An experiment (CLOUD7 campaign) was set up at the CLOUD (Cosmics Leaving OUtdoor Droplets) chamber to investigate the quantita...

  5. Ammonia Gas Sensing Behavior of Tanninsulfonic Acid Doped Polyaniline-TiO2 Composite

    Venu Gopal Bairi; Bourdo, Shawn E.; Nicolas Sacre; Dev Nair; Berry, Brian C.; Biris, Alexandru S; Tito Viswanathan

    2015-01-01

    A highly active tannin doped polyaniline-TiO2 composite ammonia gas sensor was developed and the mechanism behind the gas sensing activity was reported for the first time. A tanninsulfonic acid doped polyaniline (TANIPANI)-titanium dioxide nanocomposite was synthesized by an in situ polymerization of aniline in the presence of tanninsulfonic acid and titanium dioxide nanoparticles. X-ray diffraction and thermogravimetric analysis were utilized to determine the incorporation of TiO2 in TANIPAN...

  6. The Chemistry Scoring Index (CSI: A Hazard-Based Scoring and Ranking Tool for Chemicals and Products Used in the Oil and Gas Industry

    Tim Verslycke

    2014-06-01

    Full Text Available A large portfolio of chemicals and products is needed to meet the wide range of performance requirements of the oil and gas industry. The oil and gas industry is under increased scrutiny from regulators, environmental groups, the public, and other stakeholders for use of their chemicals. In response, industry is increasingly incorporating “greener” products and practices but is struggling to define and quantify what exactly constitutes “green” in the absence of a universally accepted definition. We recently developed the Chemistry Scoring Index (CSI which is ultimately intended to be a globally implementable tool that comprehensively scores and ranks hazards to human health, safety, and the environment for products used in oil and gas operations. CSI scores are assigned to products designed for the same use (e.g., surfactants, catalysts on the basis of product composition as well as intrinsic hazard properties and data availability for each product component. As such, products with a lower CSI score within a product use group are considered to have a lower intrinsic hazard compared to other products within the same use group. The CSI provides a powerful tool to evaluate relative product hazards; to review and assess product portfolios; and to aid in the formulation of products.

  7. Development of a gas phase source for perfluoroalkyl acids to examine atmospheric sampling methods.

    MacInnis, John J; VandenBoer, Trevor C; Young, Cora J

    2016-06-21

    An inability to produce environmentally relevant gaseous mixing ratios of perfluoroalkyl acids (PFAAs), ubiquitous global contaminants, limits the analytical reliability of atmospheric chemists to make accurate gas and particulate measurements that are demonstrably free of interferences due to sampling artefacts. A gas phase source for PFAAs based on the acid displacement mechanism using perfluoropropionate (PFPrA), perfluorobutanoate (PFBA), perfluorohexanoate (PFHxA), and perfluorooctanoate (PFOA) has been constructed. The displacement efficiency of gas phase perfluorocarboxylic acids (PFCAs) is inversely related to chain length. Decreasing displacement efficiencies for PFPrA, PFBA, PFHxA, and PFOA were 90% ± 20%, 40% ± 10%, 40% ± 10%, 9% ± 4%, respectively. Generating detectable amounts of gas phase perfluorosulfonic acids (PFSAs) was not possible. It is likely that lower vapour pressure and much higher acidity play a role in this lack of emission. PFCA emission rates were not elevated by increasing relative humidity (25%-75%), nor flow rate of carrier gas from 33-111 sccm. Overall, reproducible gaseous production of PFCAs was within the error of the production of hydrochloric acid (HCl) as a displacing acid (±20%) and was accomplished using a dry nitrogen flow of 33 ± 2 sccm. A reproducible mass emission rate of 0.97 ± 0.10 ng min(-1) (n = 8) was observed for PFBA. This is equivalent to an atmospheric mixing ratio of 12 ppmv, which is easily diluted to environmentally relevant mixing ratios of PFBA. Conversely, generating gas phase perfluorononanoic acid (PFNA) by sublimating the solid acid under the same conditions produced a mass emission rate of 2800 ng min(-1), which is equivalent to a mixing ratio of 18 ppthv and over a million times higher than suspected atmospheric levels. Thus, for analytical certification of atmospheric sampling methods, generating gas phase standards for PFCAs is best accomplished using acid displacement under dry conditions

  8. Methacrylic acid obtaining in the presence of vanadium-containing catalysts in gas phase

    Івасів, Володимир Васильович

    2012-01-01

    In the article regularities of methacrylic acid obtaining by the aldol condensation of propionic acid with formaldehyde in the presence of B2O3 – P2O5 – V2O5 catalysts in gas phase have been investigated

  9. Rapid determination of dipicolinic acid in the spores of Clostridium species by gas-liquid chromatography.

    Tabor, M W; MacGee, J; Holland, J W

    1976-01-01

    A gas-liquid chromatographic procedure has been developed to quantitate dipicolinic acid in bacterial spores. The culture, washed from a plate, was hydrolyzed with acid containing the internal standard, pyridine-2,4-dicarboxylate, and then extracted into methyl isobutyl ketone. The internal standard and dipicolinic acid were then extracted into a small volume of trimethylphenylammonium hydroxide. Injection of the resultant quaternary ammonium salts into a gas chromatograph yielded, via thermal decomposition, the methyl ester derivatives of the dipicolinic acid and the internal standard. The amount of dipicolinic acid in the sample was determined from a standard curve. The method was sensitive to 100 ng of dipicolinic acid per sample and was 1,000 to 5,000 times more sensitive than the commonly used methods. Preparation of the sample required less than 1.5 h and less than 15 min of the analyst's time. PMID:942206

  10. Synthesis of porous starch xerogels modified with mercaptosuccinic acid to remove hazardous gardenia yellow.

    Bao, Liping; Zhu, Xinyi; Dai, Hongxia; Tao, Yongxin; Zhou, Xiaoying; Liu, Wenjie; Kong, Yong

    2016-08-01

    Mercaptosuccinic acid (MSA) molecules were inserted into potato starch, leading to the breaking of intrinsic H-bonds within macromolecular chains of starch and the formation of intermolecular H-bonds between MSA and starch, which could be verified by Fourier transform infrared spectroscopy (FT-TR). MSA modified porous starch xerogels (PSX/MSA) were obtained after freeze-drying the MSA modified starch, and they were characterized by field emission scanning electron microscopy (FESEM), exhibiting the intriguing porous structure due to the separation of starch chains by MSA molecules. The PSX/MSA were then used as the adsorbents to remove gardenia yellow (GY), a natural colorant with genotoxicity. Due to the porous structure of PSX and the introduced carboxyl groups from MSA, the adsorption capacity of the PSX/MSA was much higher than that of the starch xerogels alone (SX). The adsorption behaviors of GY by the PSX/MSA fitted both the Freundlich isotherm model and the pseudo-second-order kinetic model, and the efficient adsorption of GY suggested that the PSX/MSA might be potential adsorbents for the removal of dyes from contaminated aquatic systems. PMID:27151673

  11. Poly(L-lactic acid) membranes: absence of genotoxic hazard and potential for drug delivery.

    Uzun, Nelson; Martins, Thomás Duzzi; Teixeira, Gabriella Machado; Cunha, Nayanne Larissa; Oliveira, Rogério Belle; Nassar, Eduardo José; Dos Santos, Raquel Alves

    2015-01-22

    The use of poly(L-lactic acid) (PLA) has been considered an important alternative for medical devices once this polyester presents biomechanical, optical and biodegradable properties. Moreover, the use of PLA results in less inflammatory reactions and more recently it has been proposed its application in drug delivery systems. Genotoxicological evaluations are considered part of the battery assays in toxicological analysis. Considering the wide applications of PLA, the present work evaluated the potential cytotoxic and genotoxic effects of PLA in CHO-K1 cells, as well as its physicochemical properties. No cytotoxic effects of PLA were detected by colorimetric tetrazolium assay (XTT) analysis, and the clonogenic survival assay showed that PLA did not disrupt the replicative cell homeostasis, neither exhibited genotoxic effects as evidenced by comet and micronucleus assays. Thermogravimetric properties of PLA were not altered after contact with cells and this film exhibited ability in absorb and release Europium(III) complex. All these data suggest genotoxicological safety of PLA for further applications in drug delivery systems. PMID:25479058

  12. Protective Effects Of ALPHA Lipoic Acid On GAMMA Irradiation Hazards In Male Rats

    Ionizing radiation is known to increase the oxidative stress and damage the body organs. Alpha lipoic acid (ALA) is a powerful antioxidant that neutralizes free radicals in both fatty and watery regions of cells, so, this study was designed to investigate the efficacy of ALA on radiation-induced injury in male rats. Animals were randomly distributed into 5 groups, each of 24 rats. The groups of animals were categorized as control group, ALA group, irradiated group, simultaneously irradiated ALA group and pre-irradiated ALA group. A fractionated dose of irradiation (2 Gy each 3 days to reach accumulative dose levels of 6 Gy) caused hepatic, renal and cardiac damage which manifested biochemically as elevation in the levels of serum liver alanine, aspartate aminotransferases (ALT and AST) , alkaline phosphatase (ALP), heart creatine kinase (CK-MB), kidney urea and creatinine. Administration of ALA at a dose level of 30 mg/kg /day orally for 7 days before exposure and 9 days throughout the irradiation period induced more significant improvement than the simultaneously irradiated ALA group as compared to the irradiated group. The findings of this study suggest that ALA can potentially be used clinically to prevent irradiation-induced hepato, renal and cardiac disorders

  13. 46 CFR 153.1046 - Sulfuric acid.

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Sulfuric acid. 153.1046 Section 153.1046 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Operations Special Cargo Procedures § 153.1046 Sulfuric acid. No person may...

  14. Ab initio and density functional theory studies of the structure,gas-phase acidity and aromaticity of tetraselenosquaric acid

    周立新

    2000-01-01

    Results or ab initio selr-consistent-field ( SCF) and denityfunctional theory (DFr) calculations of the gas-phase structure, acidity (free energy of deprotona tion, △G°) and aroma ticity of tetraselenosquaric acid (3, 4-diseleny-3-cyclobutene-1,2-diselenone, H2C4Se4) are reported.The global minimu found on the potenial energy surface of tetraselenosquaric acid presents a planar conformation. The ZZ isomer was found to have the lowest energy among the three planar conformers and the ZZ and ZE is omers are very close in energy. The optimized geometric parameters exhibit a bond length equalization relative to reference compounds, cyclobutanediselenone, and cyclobutenediselenol. The computed aromaic stabilization energy(ASE)by homodesmotic reaction is -77.4 (MP2(fu)/6 - 311 + G* *//RHF/6 - 311 + G* * ) and - 54.8 kJ/mol (B3LYP/6 - 311 + G* * //B3LYP/6 - 311 + G* * ). The aromaticity of tetraselenosquaric acid is indicated by the calculated diamagnetic susceptibility exaltation (A) - 19.13 (CSGT(IGAIM) - RHF/6 - 311 + G**//RHF/6 - 311 + G* * and - 32.91(4π· 10-6 m3/mo l)(CSGT(IGA1M)-B3LYP/6 - 311 + G* *//B3LYP/6 - 311 + G* * ).Thus, tetraselenosquaric acid fulfils the geometric, energetic and magnetic criteria of aromaticity. The calculated gas-phase acidity is △G10(298K) = 1257.7 and △G20(298K) = 1617.1 kJ/mol. Hence, tetraselenosquarc acid is the stronest acid among the three squaric acids (3,4-dihydroxy-3-cyclobutene-1,2-dione, H2C4O4, 3,4-dithiohydroxy-3- cyclobutene-1,2-dithione, H2C4S4, 3,4- diselenyl-3- cyclobutene- 1,2-diselenone, H2C4Se4).

  15. Gas-Phase Structures of Ketene and Acetic Acid from Acetic Anhydride Using Very-High-Temperature Gas Electron Diffraction.

    Atkinson, Sandra J; Noble-Eddy, Robert; Masters, Sarah L

    2016-03-31

    The gas-phase molecular structure of ketene has been determined using samples generated by the pyrolysis of acetic anhydride (giving acetic acid and ketene), using one permutation of the very-high-temperature (VHT) inlet nozzle system designed and constructed for the gas electron diffraction (GED) apparatus based at the University of Canterbury. The gas-phase structures of acetic anhydride, acetic acid, and ketene are presented and compared to previous electron diffraction and microwave spectroscopy data to show improvements in data extraction and manipulation with current methods. Acetic anhydride was modeled with two conformers, rather than a complex dynamic model as in the previous study, to allow for inclusion of multiple pyrolysis products. The redetermined gas-phase structure of acetic anhydride (obtained using the structure analysis restrained by ab initio calculations for electron diffraction method) was compared to that from the original study, providing an improvement on the description of the low vibrational torsions compared to the dynamic model. Parameters for ketene and acetic acid (both generated by the pyrolysis of acetic anhydride) were also refined with higher accuracy than previously reported in GED studies, with structural parameter comparisons being made to prior experimental and theoretical studies. PMID:26916368

  16. Extraction of Fatty Acids for Capillary Gas Chromatography Analysis

    sprotocols

    2015-01-01

    Authors: Wei Zou ### Abstract Fatty acids are major energy provider for the human body. Over intake of fatty acids causes obesity. ### Reagents 1. CM mixture: chloroform: methanol: butylated hydroxytolune (BHT) = 2 L : 1 L : 100 mg. - 0.5 N methanolic sodium hydroxide (NaOH) (10 g NaOH in 500 mL methanol): mix the solution for 15 minutes with a stir bar. Don’t heat the mixture because methanol is highly flammable. - 14% Boron Trifluoride (BF3) in methanol (commercially ...

  17. GAS PERMEATION PROPERTIES OF POLY(LACTIC ACID). (R826733)

    AbstractThe need for the development of polymeric materials based on renewable resources has led to the development of poly(lactic acid) (PLA) which is being produced from a feedstock of corn rather than petroleum. The present study examines the permeation of nitrogen...

  18. Limiting Current of Oxygen Reduction on Gas-Diffusion Electrodes for Phosphoric Acid Fuel Cells

    Li, Qingfeng; Gang, Xiao; Hjuler, Hans Aage;

    1994-01-01

    on polytetrafluorine-ethyl bonded gas-diffusion electordes in phosphoric acid with and without fluorinated additives. This provides an alternative to estimate the film thickness by combining it with the acid-adsorption measurements and the porosity analysis of the catalyst layer. It was noticed that the limiting...... expression for the limiting current density. The acid-film thickness estimated this way was found to be of 0.1 mum order of magnitude for the two types of electrodes used in phosphoric acid with and without fluorinated additives at 150-degrees-C....

  19. Gas phase measurements of mono-fluoro-benzoic acids and the dimer of 3-fluoro-benzoic acid

    The microwave spectrum of the mono-fluoro-benzoic acids, 2-fluoro-, 3-fluoro-, and 4-fluoro-benzoic acid have been measured in the frequency range of 4-14 GHz using a pulsed beam Fourier transform microwave spectrometer. Measured rotational transition lines were assigned and fit using a rigid rotor Hamiltonian. Assignments were made for 3 conformers of 2-fluorobenzoic acid, 2 conformers of 3-fluorobenzoic acid, and 1 conformer of 4-fluorobenzoic acid. Additionally, the gas phase homodimer of 3-fluorobenzoic acid was detected, and the spectra showed evidence of proton tunneling. Experimental rotational constants are A(0+) = 1151.8(5), B(0+) = 100.3(5), C(0+) = 87.64(3) MHz and A(0−) = 1152.2(5), B(0−) = 100.7(5), C(0−) = 88.85(3) MHz for the two ground vibrational states split by the proton tunneling motion. The tunneling splitting (ΔE) is approximately 560 MHz. This homodimer appears to be the largest carboxylic acid dimer observed with F-T microwave spectroscopy

  20. Gas phase measurements of mono-fluoro-benzoic acids and the dimer of 3-fluoro-benzoic acid

    Daly, Adam M. [Jet Propulsion Laboratory, California Institute of Technology, Pasedena, California 91106 (United States); Carey, Spencer J.; Pejlovas, Aaron M.; Li, Kexin; Kukolich, Stephen G., E-mail: Kukolich@u.arizona.edu [Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721 (United States); Kang, Lu [Department of Chemistry and Biochemistry, Kennesaw State University, Kennesaw, Georgia 30144 (United States)

    2015-04-14

    The microwave spectrum of the mono-fluoro-benzoic acids, 2-fluoro-, 3-fluoro-, and 4-fluoro-benzoic acid have been measured in the frequency range of 4-14 GHz using a pulsed beam Fourier transform microwave spectrometer. Measured rotational transition lines were assigned and fit using a rigid rotor Hamiltonian. Assignments were made for 3 conformers of 2-fluorobenzoic acid, 2 conformers of 3-fluorobenzoic acid, and 1 conformer of 4-fluorobenzoic acid. Additionally, the gas phase homodimer of 3-fluorobenzoic acid was detected, and the spectra showed evidence of proton tunneling. Experimental rotational constants are A(0{sup +}) = 1151.8(5), B(0{sup +}) = 100.3(5), C(0{sup +}) = 87.64(3) MHz and A(0{sup −}) = 1152.2(5), B(0{sup −}) = 100.7(5), C(0{sup −}) = 88.85(3) MHz for the two ground vibrational states split by the proton tunneling motion. The tunneling splitting (ΔE) is approximately 560 MHz. This homodimer appears to be the largest carboxylic acid dimer observed with F-T microwave spectroscopy.

  1. Fluoroalkyl chloroformates in treating amino acids for gas chromatographic analysis

    Hušek, Petr; Šimek, Petr; Hartvich, Petr; Zahradníčková, Helena

    2008-01-01

    Roč. 1186, 1/2 (2008), s. 391-400. ISSN 0021-9673 R&D Projects: GA ČR GA203/04/0192; GA ČR GA303/06/1674 Institutional research plan: CEZ:AV0Z50070508 Keywords : amino acids * derivatization * pentafluoropropyl- and heptafluorobutyl chloroformates Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.756, year: 2008

  2. Modeling acid-gas generation from boiling chloride brines

    Sonnenthal Eric; Spycher Nicolas; Zhang Guoxiang; Steefel Carl

    2009-01-01

    Abstract Background This study investigates the generation of HCl and other acid gases from boiling calcium chloride dominated waters at atmospheric pressure, primarily using numerical modeling. The main focus of this investigation relates to the long-term geologic disposal of nuclear waste at Yucca Mountain, Nevada, where pore waters around waste-emplacement tunnels are expected to undergo boiling and evaporative concentration as a result of the heat released by spent nuclear fuel. Processes...

  3. Gas-Phase Reactivity of Carboxylic Acid Functional Groups with Carbodiimides

    Prentice, Boone M.; Gilbert, Joshua D.; Stutzman, John R.; Forrest, William P.; McLuckey, Scott A.

    2012-01-01

    Gas-phase modification of carboxylic acid functionalities is performed via ion/ion reactions with carbodiimide reagents [N-cyclohexyl-N′-(2-morpholinoethyl)carbodiimide (CMC) and [3-(3-Ethylcarbodiimide-1-yl)propyl]trimethylaminium (ECPT). Gas-phase ion/ion covalent chemistry requires the formation of a long-lived complex. In this instance, the complex is stabilized by an electrostatic interaction between the fixed charge quaternary ammonium group of the carbodiimide reagent cation and the an...

  4. Effect of oxygen enrichment in air on acid gas combustion under Claus conditions

    Ibrahim, Salisu

    2013-09-01

    Results are presented to examine the combustion of acid gas (H2S and CO2) in hydrogen-fueled flames using a mixture of oxygen and nitrogen under Claus conditions (Φ = 3). Specifically the effect of oxygen enrichment in the above flames is examined. The compositions of acid gas examined are100% H2S and 50% H2S/50% CO2 with different percentages of oxygen enrichment (0%, 19.3% and 69.3%) in the oxygen/nitrogen mixtures. The results revealed that combustion of acid gas formed SO2 wherein the mole fraction of SO2 increased to an asymptotic value at all the oxygen concentrations examined. In addition, increase in oxygen enrichment of the air resulted in increased amounts of SO2 rather than the formation of more desirable elemental sulfur. In case of 50% H2S/50% CO2 acid gas, carbon monoxide mole fraction increased with oxygen enrichment which is an indicator to the availability of additional amounts of oxygen into the reaction pool. This gas mixture resulted in the formation of other sulfurous–carbonaceous compounds (COS and CS2) due to the presence of carbon monoxide. The results showed that the rate of COS formation increased with oxygen enrichment due to the availability of higher amounts of CO while that of CS2 reduced. The global reactions responsible for this observed phenomenon are presented.

  5. Estimation of Fatty Acids in Corn Oil by Gas Capillary Chromatography

    Fatty acids provide energy as well as play important role in some cellular structures like cell membrane and certain hormones. Saturated fatty acids are usually found in animal products and in some vegetable oils as well. These saturated fatty acids may be a factor in weight gain and obesity but eating them in moderate amounts may not be damaging to health of every person. Monounsaturated fatty acids can lower blood levels of low density lipoprotein cholesterol and have potential to increase blood levels of high density lipoprotein cholesterol and by this way plays protective role against heart disease. The omega 3 and 6 fatty acids have vital roles in many biological systems such as nervous, immune, cardiovascular, dermal and vision systems. Therefore, it is essential to optimize the instrumental conditions and column specification for the estimation of various fatty acids in the oil, which was considered in the current study using Gas Capillary Chromatography. (author)

  6. The Role of Acid Strength of Modified NaX Zeoliteson Gas Phase Ethylation of Benzene

    Sanghamitra Barman

    2010-01-01

    Full Text Available The role of acid strength of modified NaX zeolites in gas phase ethylation of benzene were studied over Ce exchanged NaX zeolite of different types. Acidity of the modified zeolite was investigated by means of adsorbing ammonia at different temperature. The conversion of reactantsvaries with the acid strength as well as the different types of the zeolites. The strong acid sites are active centers while the weak acid sites are inactive. The influences of various process parameters such as temperature, space-time and the feed ratio of benzene to ethanol on benzene conversion over most acidic zeolite were studied. The kinetic and adsorption constants of the rate equations were estimated by the best fit. From the estimated kinetic constants, the activation energies and frequency factors for various reactions were determined. The activation energy values compared well with those reported by other investigators for same reactions over similar catalysts.

  7. Identification of bound alcohols in soil humic acids by gas chromatography-mass spectrometry

    Berthier, Gersende; Dou, Sen; Peakman, Torren; Lichtfouse, Eric

    2000-01-01

    International audience Humic acids are complex, partly macromolecular, yellow-brownish substances occurring in soils, waters and sediments. In order to shed some light on their molecular structure, crop humic acids were cleaved by alkaline hydrolysis (KOH). The products were fractionated by thin layer chromatography to give mono-alcohols which were analysed as acetate derivatives by gas chromatography coupled to mass spectrometry. Linear alcohols, sterols, stanols and plant-derived triterp...

  8. Preparation of sphingolipid fatty acid methyl esters for determination by gas-liquid chromatography.

    MacGee, J; Williams, M G

    1981-01-30

    Sphingolipid fatty acids are first converted to a mixture of free acids and their n-butyl esters by heating the specimen at 85 degree C in aqueous butanolic hydrogen chloride; the butyl esters are then saponified with methanolic potassium hydroxide. After acidification and extraction into hexane, the fatty acids are extracted into a very small volume of aqueous trimethyl(m-trifluorotolyl)ammonium hydroxide (TMTFTH), injection of an aliquot of the TMTFTH extract into the gas chromatograph yields the fatty acid methyl esters by pyrolytic methylation of the quaternary ammonium salts of the fatty acids. The preparation of a specimen ready for the gas--liquid chromatographic (GLC) analysis with quantitative recovery of the sphingolipid fatty acids can be accomplished in less than 2 h. By comparison, none of a number of well-accepted techniques for the release of sphingomyelin fatty acids by hydrolysis or methanolysis released the fatty acids quantitatively in less than 3 h, and all required additional manipulations before GLC analysis. PMID:7217267

  9. Estimating Fatty Acid Composition of Infant Buccal Mucosal Cells by Capillary Gas Chromatography

    CHEN Fei; ZHANG Wei-li; LI Fang; ZHU Xiao-dong; ZHU Jian-xing

    2008-01-01

    Long chain polyunsaturated fatty adds, i. e., docosahexaenoic acid (DHA or C22 : 6n -3), arachidonic acid (AA or C20 : 4n - 6) have been identified as essential fatty acids and play an important role in growth and development of infants. Mensurement of fatty acid composition is usually by collection of blood, but to obtain blood in infants is difficult. Nowadays, the fatty acid composition can be estimated by collecting buccal mucosal cells, which can avoid repeated blood sampling. The purpose of this paper is to compare the fatty acid composition of cheek calls with that of plasma and red blood cells (RBCs). In this study, twenty-seven infants were enrolled, and buccal mucosal cells and blood samples were obtained from these infants of the same time. Fatty acid composition of buccal mucesal cells, plasma and RBCs were measured by capillary gas chromatography. The results show that the contents of AA and DHA in the buccal mucosal cells are correlated well with that in the plasma [r=0.36 (P=0.042) and r=0.38 (P=0.033), respectively]. The ratio of AA to DHA is 1.32% in buccal mucosal cells, 1.60% in plasma and 1.55% in RBCs and there are no significant differences among groups (P = 0.134). It shows that the fatty acid composition in buccal mucosal cells can reflect the fat nutrition status in infants and can be detected by capillary gas chromatography. Estimating fatty acid composition of buccal mucosal cells in infants by capillary gas chromatography is feasible, and because of its noninvasiveness, it can be suitable for nutrition research in infants.

  10. Influence of tryptophan loading on urinary excretion of anthranilic acid and 3-hydroxyanthranilic acid by men and women as determined by alkali flame ionization gas chromatography

    Poll, J.M. van der; Vink, M.; Schrijver, J.; Odink, J.

    1986-01-01

    A gas chromatographic method with alkali flame ionization detection is described for the determination of urinary total (free and conjugated) anthranilic acid (AA) and 3-hydroxyanthranilic acid (HAA) as their pentafluorobenzyl esters. Prior to analysis, urine was hydrolysed using hydrochloric acid i

  11. Gas diffusion electrode setup for catalyst testing in concentrated phosphoric acid at elevated temperatures

    Wiberg, Gustav Karl Henrik; Fleige, Michael; Arenz, Matthias

    2015-01-01

    We present a detailed description of the construction and testing of an electrochemical cell setup allowing the investigation of a gas diffusion electrode containing carbon supported high surface area catalysts. The setup is designed for measurements in concentrated phosphoric acid at elevated...

  12. Amino acid salt solutions as solvents in CO2 capture from flue gas

    Lerche, Benedicte Mai; Thomsen, Kaj; Stenby, Erling Halfdan

    solutions is their ability to form solid precipitates upon the absorption of CO2. The occurrence of crystallization offers the possibility of increasing the CO2 loading capacity of the solvent. However, precipitation can also have negative effect on the CO2 capture process. The chemical nature of the solid...... loading capacity of aqueous solutions of the potassium salts of selected amino-acids (glycine, taurine, lysine proline, and glutamic acid) were examined, and the relation between the initial amino acid salt concentration and precipitation ability of each solution were determined. Experiments were...... glycine, taurine, and lysine, while in the case of proline, and glutamic acid, the precipitate was found to be bicarbonate. These results give an important contribution to further understanding the potential of amino acid salt solutions in CO2 capture from flue gas....

  13. [Gas chromatographic determination of formic acid in urine as carbon monoxide (author's transl)].

    Angerer, J

    1976-02-01

    A gas chromatographic method for determining formic acid in human urine is described. The analytical reliability of this method fullfills the criteria of statistical quality control. The rate of recovery is 101.2 to 105.7% the variability coefficients lie between 2.9 and 7.2%. The selectivity of this method is demonstrated by analysing a group of components normally occuring in urine which did not interfere with the determination of formic acid. The detection limit of about 4.3 mumol/1 formic acid in urine permits the determination of the concentration of formic acid in the urine of normal persons. The concentrations of formic acid in the urine of a group of normal persons lies between 0 and 2.79 mmol/1. The average concentration was 0.39 +/- 0.60 mmol/1. PMID:1249528

  14. Gas-Phase Reactivity of Carboxylic Acid Functional Groups with Carbodiimides

    Prentice, Boone M.; Gilbert, Joshua D.; Stutzman, John R.; Forrest, William P.; McLuckey, Scott A.

    2013-01-01

    Gas-phase modification of carboxylic acid functionalities is performed via ion/ion reactions with carbodiimide reagents [ N-cyclohexyl- N'-(2-morpholinoethyl)carbodiimide (CMC) and [3-(3-Ethylcarbodiimide-1-yl)propyl]trimethylaminium (ECPT)]. Gas-phase ion/ion covalent chemistry requires the formation of a long-lived complex. In this instance, the complex is stabilized by an electrostatic interaction between the fixed charge quaternary ammonium group of the carbodiimide reagent cation and the analyte dianion. Subsequent activation results in characteristic loss of an isocyanate derivative from one side of the carbodiimide functionality, a signature for this covalent chemistry. The resulting amide bond is formed on the analyte at the site of the original carboxylic acid. Reactions involving analytes that do not contain available carboxylic acid groups (e.g., they have been converted to sodium salts) or reagents that do not have the carbodiimide functionality do not undergo a covalent reaction. This chemistry is demonstrated using PAMAM generation 0.5 dendrimer, ethylenediaminetetraacetic acid (EDTA), and the model peptide DGAILDGAILD. This work demonstrates the selective gas-phase covalent modification of carboxylic acid functionalities.

  15. Impact of individual acid flue gas components on mercury capture by heat-treated activated carbon

    Jian-ming ZHENG; Jin-song ZHOU; Zhong-yang LUO; Ke-fa CEN

    2012-01-01

    Elemental mercury capture on heat-treated activated carbon (TAC) was studied using a laboratory-scale fixed bed reactor.The capability of TAC to perform Hg0 capture under both N2 and baseline gas atmospheres was studied and the effects of common acid gas constituents were evaluated individually to avoid complications resulting from the coexistence of multiple components.The results suggest that surface functional groups (SFGs) on activated carbon (AC) are vital to Hg0 capture in the absence of acid gases.Meanwhile,the presence of acid gas components coupled with defective graphitic lattices on TAC plays an important role in effective Hg0 capture.The presence of HCl,NO2,and NO individually in basic gases markedly enhances Hg0 capture on TAC due to the heterogeneous oxidation of Hg0 on acidic sites created on the carbon surface and catalysis by the defective graphitic lattices on TAC.Similarly,the presence of SO2 improves Hg0 capture by about 20%.This improvement likely results from the deposition of sulfur groups on the AC surface and oxidation of the elemental mercury by SO2 due to catalysis on the carbon surface.Furthermore,O2 exhibits a synergistic effect on Hg0 oxidation and capture when acid gases are present in the flue gases.

  16. Gas chromatography-vacuum ultraviolet spectroscopy for analysis of fatty acid methyl esters.

    Fan, Hui; Smuts, Jonathan; Bai, Ling; Walsh, Phillip; Armstrong, Daniel W; Schug, Kevin A

    2016-03-01

    A new vacuum ultraviolet (VUV) detector for gas chromatography was recently developed and applied to fatty acid methyl ester (FAME) analysis. VUV detection features full spectral acquisition in a wavelength range of 115-240nm, where virtually all chemical species absorb. VUV absorption spectra of 37 FAMEs, including saturated, monounsaturated, and polyunsaturated types were recorded. Unsaturated FAMEs show significantly different gas phase absorption profiles than saturated ones, and these classes can be easily distinguished with the VUV detector. Another advantage includes differentiating cis/trans-isomeric FAMEs (e.g. oleic acid methyl ester and linoleic acid methyl ester isomers) and the ability to use VUV data analysis software for deconvolution of co-eluting signals. As a universal detector, VUV also provides high specificity, sensitivity, and a fast data acquisition rate, making it a powerful tool for fatty acid screening when combined with gas chromatography. The fatty acid profile of several food oil samples (olive, canola, vegetable, corn, sunflower and peanut oils) were analyzed in this study to demonstrate applicability to real world samples. PMID:26471553

  17. CO2 Capture from Flue Gas using Amino Acid Salt Solutions

    Lerche, Benedicte Mai; Stenby, Erling Halfdan; Thomsen, Kaj

    2009-01-01

    The reversible absorption of CO2 into a chemical solvent is currently the leading CO2 capture technology. Available solvents are almost exclusively based on aqueous alkanolamine solutions, which entail both economic and environmental complications, making the commercialization of the technology...... difficult. Amino acid salt solutions have emerged as an alternative to the alkanolamine solutions. A number of advantages make amino acid salt solutions attractive solvents for CO2 capture from flue gas. In the present study CO2 absorption in aqueous solutions of 0.5 M potassium glycinate and 0.5 M...... monoethanolamine (MEA) were performed, using a stirred cell reactor experimental setup. The absorption of gas containing 10 mol % CO2 and 90 mol % N2 was followed by measuring the percentage of CO2 in the outlet gas. Also the temperature and pH in the solutions were measured during the absorption. The results...

  18. Hydrophobic amino acids as a new class of kinetic inhibitors for gas hydrate formation

    Sa, Jeong-Hoon; Kwak, Gye-Hoon; Lee, Bo Ram; Park, Da-Hye; Han, Kunwoo; Lee, Kun-Hong

    2013-08-01

    As the foundation of energy industry moves towards gas, flow assurance technology preventing pipelines from hydrate blockages becomes increasingly significant. However, the principle of hydrate inhibition is still poorly understood. Here, we examined natural hydrophobic amino acids as novel kinetic hydrate inhibitors (KHIs), and investigated hydrate inhibition phenomena by using them as a model system. Amino acids with lower hydrophobicity were found to be better KHIs to delay nucleation and retard growth, working by disrupting the water hydrogen bond network, while those with higher hydrophobicity strengthened the local water structure. It was found that perturbation of the water structure around KHIs plays a critical role in hydrate inhibition. This suggestion of a new class of KHIs will aid development of KHIs with enhanced biodegradability, and the present findings will accelerate the improved control of hydrate formation for natural gas exploitation and the utilization of hydrates as next-generation gas capture media.

  19. A shallow-layer model for heavy gas dispersion from natural sources: Application and hazard assessment at Caldara di Manziana, Italy

    Costa, A.; Chiodini, G.; Granieri, D.; Folch, A.; Hankin, R. K. S.; Caliro, S.; Avino, R.; Cardellini, C.

    2008-03-01

    Several nonvolcanic sources in central Italy emit a large amount of carbon dioxide (CO2). Under stable atmospheric conditions and/or in the presence of topographic depressions, the concentration of CO2, which has a molecular mass greater than that of air, can reach high values that are lethal to humans or animals. Several episodes of this phenomenon were recorded in central Italy and elsewhere. In order to validate a model for the dispersion of a heavy gas and to assess the consequent hazard, we applied and tested the code TWODEE-2, an improved version of the established TWODEE model, which is based on a shallow-layer approach that uses depth-averaged variables to describe the flow behavior of dense gas over complex topography. We present results for a vented CO2 release at Caldara di Manziana in central Italy. We find that the model gives reliable results when the input quantity can be properly defined. Moreover, we show that the model can be a useful tool for gas hazard assessment by evaluating where and when lethal concentrations for humans and animals are reached.

  20. Analyzing solubility of acid gas and light alkanes in triethylene glycol

    Alireza Bahadori; Had B.Vuthaluru; Saeid Mokhatab

    2008-01-01

    Physical solvents such as ethylene glycol (EG), diethylene glycol (DEG), and triethylene glycol (TEG) are commonly used in wet gas dehydration processes with TEG being the most popular due to ease of regeneration and low solvent losses. Unfortunately, TEG absorbs significantly more hydrocarbons and acid gases than EG or DEG. Quantifying this amount of absorption is therefore critical in order to minimize hydrocarbon losses or to optimize hydrocarbon recovery depending on the objective of the process. In this article, a new correlation that fully covers the operating ranges of TEG dehydration units is developed in order to determine the solubility of light alkanes and acid gases in TEG solvent. The influence of several parameters on hydrocarbon and acid gas solubility including temperature, pressure, and solvent content is also examined.

  1. TECHNICAL AND OPERATING SUPPORT FOR PILOT DEMONSTRATION OF MORPHYSORB ACID GAS REMOVAL PROCESS

    Nagaraju Palla; Dennis Leppin

    2004-02-01

    Over the past 14 years, the Gas Technology Institute and jointly with Uhde since 1997 developing Morphysorb{reg_sign} a new physical solvent-based acid gas removal process. Based on extensive laboratory, bench, pilot-plant scale experiments and computer simulations, DEGT Gas Transmission Company, Canada (DEGT) has chosen the process for use at its Kwoen processing facility near Chetwynd, British Columbia, Canada as the first commercial application for the Morphysorb process. DOE co-funded the development of the Morphysorb process in various stages of development. DOE funded the production of this report to ensure that the results of the work would be readily available to potential users of the process in the United States. The Kwoen Plant is designed to process 300 MMscfd of raw natural gas at 1,080-psia pressure. The sour natural gas contains 20 to 25 percent H{sub 2}S and CO{sub 2}. The plant reduces the acid gas content by about 50% and injects the removed H{sub 2}S and CO{sub 2} into an injection well. The Kwoen plant has been operating since August 2002. Morphysorb{reg_sign} is a physical solvent-based process used for the bulk removal of CO{sub 2} and/or H{sub 2}S from natural gas and other gaseous streams. The solvent consists of N-Formyl morpholine and other morpholine derivatives. This process is particularly effective for high-pressure and high acid-gas applications and offers substantial savings in investment and operating cost compared to competitive physical solvent-based processes. GTI and DEGT first entered into an agreement in 2002 to test the Morphysorb process at their Kwoen Gas Treating Plant in northern BC. The process is operating successfully without any solvent related problems and has between DEGTC and GTI. As of December 2003, about 90 Bcf of sour gas was processed. Of this about 8 Bcf of acid gas containing mainly H{sub 2}S and CO{sub 2} was injected back into the depleted reservoir and 82 Bcf sent for further processing at DEGTC

  2. Determination of 4-Chloroindole-3-Acetic Acid Methyl Ester in Lathyrus Vicia and Pisum by Gas Chromatography - Mass Spectrometry

    Engvild, Kjeld Christensen; Egsgaard, Helge; Larsen, Elfinn

    1980-01-01

    4-Chloroindole-3-acetic acid methyl ester was identified unequivocally in Lathyrus latifolius L., Vicia faba L. and Pisum sativum L. by thin layer chromatography, gas chromatography and mass spectrometry. The gas chromatographic system was able to separate underivatized chloroindole-3-acetic acid...... methyl ester isomers. The quantitative determination of 4-chloroindole-3-acetic acid methyl ester in immature seeds of these three species was performed by gas chromatography – mass spectrometry using deuterium labelled 4-chloro-indole-3-acetic acid methyl ester as an internal standard. P. sativum...

  3. Noble gas dependence of single-bubble sonoluminescence in phosphoric acid

    Single-bubble sonoluminescence (SL) from a concentrated solution of phosphoric acid doped with various noble gases has been studied using a hydrochemical model. The results indicate that in agreement with experiment, the SL temperature increases with the atomic mass of the noble gases. Also, both the temperature and the intensity of SL are remarkably higher for lower partial pressures of a noble gas. Our calculations show that the maximum acquirable SL intensity from phosphoric acid is considerably greater than that of water. This mainly originates from the lower vapor pressure and the higher viscosity of phosphoric acid relative to water making the instability mechanisms completely different for these liquids. -- Highlights: ► Sonoluminescence (SL) radiation from a concentrated phosphoric acid solution has been simulated. ► The SL temperature is shown to increase with the atomic mass of noble gases. ► The difference between the noble gases is more remarkable at lower partial pressures of the gases. ► Both the temperature and the intensity of SL decrease with increment of the noble gas partial pressure in acid. ► The range of 6000–10 000 K is obtained for the SL temperature at relatively high partial pressures of the noble gases in the acid.

  4. Ruminal Methane Production on Simple Phenolic Acids Addition in in Vitro Gas Production Method

    A. Jayanegara

    2009-04-01

    Full Text Available Methane production from ruminants contributes to total global methane production, which is an important contributor to global warming. In this experiment, six sources of simple phenolic acids (benzoic, cinnamic, phenylacetic, caffeic, p-coumaric and ferulic acids at two different levels (2 and 5 mM added to hay diet were evaluated for their potential to reduce enteric methane production using in vitro Hohenheim gas production method. The measured variables were gas production, methane, organic matter digestibility (OMD, and short chain fatty acids (SCFA. The results showed that addition of cinnamic, caffeic, p-coumaric and ferulic acids at 5 mM significantly (P p-coumaric > ferulic > cinnamic. The addition of simple phenols did not significantly decrease OMD. Addition of simple phenols tends to decrease total SCFA production. It was concluded that methane decrease by addition of phenolic acids was relatively small, and the effect of phenolic acids on methane decrease depended on the source and concentration applied.

  5. Chemical ionization mass spectrometry (CIMS) may not measure all gas-phase sulfuric acid if base molecules are present

    Kurtén, T.; T. Petäjä; Smith,J; Ortega, I.K.; Sipilä, M.; Junninen, H.; M. Ehn; Vehkamäki, H.; Mauldin, L.; Worsnop, D.R.; M. Kulmala

    2010-01-01

    The state-of-the art method for measuring atmospheric gas-phase sulfuric acid is chemical ionization mass spectrometry (CIMS) based on nitrate reagent ions. Using computed proton affinities and reaction thermodynamics for the relevant charging reactions, we show that in the presence of strong bases such as amines, which tend to cluster with the sulfuric acid molecules, a significant fraction of the total gas-phase sulfuric acid may not be measured by a CIMS instrument. If this is the c...

  6. Electron beam treatment technology for exhaust gas for preventing acid rain

    Recently, accompanying the increase of the use of fossil fuel, the damage due to acid rain such as withering of trees and extinction of fishes and shells has occurred worldwide, and it has become a serious problem. The sulfur oxides and nitrogen oxides contained in exhaust gas are oxidized by the action of sunbeam to become sulfuric acid and nitric acid mists, which fall in the form of rain. Acid rain is closely related to the use of the coal containing high sulfur, and it hinders the use of coal which is rich energy source. In order to simplify the processing system for boiler exhaust gas and to reduce waste water and wastes, Ebara Corp. developed the dry simultaneous desulfurizing and denitrating technology utilizing electron beam in cooperation with Japan Atomic Energy Research Institute. The flow chart of the system applied to the exhaust gas treatment in a coal-fired thermal power station is shown. The mechanism of desulfurization and denitration, and the features of this system are described. The demonstration plant was constructed in a coal-fired thermal power station in Indianapolis, Indiana, USA, and the trial operation was completed in July, 1987. The test results are reported. (K.I.)

  7. Amino Acids and Sugars in the Gas Phase: Microwave Data for Astrochemistry

    Mata, S.; Cabezas, C.; Varela, M.; Peña, I.; Perez, C.; Blanco, S.; Sanz, M. E.; Lopez, J. C.; Alonso, J. L.

    2011-05-01

    Microwave spectroscopy, considered the most definitive gas phase structural probe, can distinguish between different conformational structures since they have unique spectroscopic constants and give separate rotational spectra. However it has been limited to molecular specimens having an appreciable vapor pressure. In general, molecules of biological importance have low vapor pressures and tend to undergo degradation upon heating. The combination of laser ablation with Fourier transform microwave spectroscopy in supersonic jets (LA-MB-FTMW) which overcomes the problems of thermal decomposition has rendered accessible the gas phase structural studies of these molecules. To date different α-, β- and γ-amino acids have been studied using this technique. Even in conformationally challenging systems the preferred conformations can be identified by rotational spectroscopy, as has been illustrated with the assignment of seven low-energy conformers in serine and threonine, six in cysteine and aspartic acid , and nine in γ-amino butyric (gaba). This technique has been successfully applied to the study of monosaccarides. Three conformers of the prototypes α-D-glucose and β-D-glucose have been characterized for the first time in the gas phase. After the first experimental observation of the monohydrated cluster of glycine, complexes between amino acids and nitrogen bases with water have also been investigated to obtain information on the changes induced in the conformational or tautomeric preferences by the addition of solvent molecules. The information given here is relevant for the unambiguous identification of these amino acids and sugars in the interstellar medium.

  8. Comparison of Genetic Parameters Estimation of Fatty Acids from Gas Chromatography and FT-IR in Holsteins

    Poulsen, Nina Aagaard; Eskildsen, C E A; Skov, Thomas;

    on fatty acids data measured from gas chromatography in 371 Danish Holstein cows. Results showed similar heritability estimates and strong genomic correlations for most of the fatty acids. However, for some fatty acids, the choice of data affected the genetic parameter estimation, which may be due to...

  9. Energy exploitation of acid gas with high H2S content by means of a chemical looping combustion system

    Highlights: • CLC can exploit the energy potential of acid gas by burning H2S. • New combustion process demonstration in a continuous CLC unit. • Highest H2S concentrations (20 vol.%) ever used in a CLC process. • Fe20γAl oxygen carrier is a suitable material for acid gas combustion. • H2S content above 20 vol.% turns the acid gas CLC into an auto-thermal process. - Abstract: In gas and petroleum industry, the waste gas stream from the sweetening process of a sour natural gas stream is commonly referred as acid gas. Chemical Looping Combustion (CLC) technology has the potential to exploit the combustible fraction of acid gas, H2S, to produce energy obtaining a flue gas highly concentrated on CO2 and SO2, which can be cost-effectively separated for subsequent applications, such as sulfuric acid production. At the same time, a concentrated CO2 stream ready for storage is obtained. The resistance of oxygen carriers to sulfur becomes crucial when an acid gas is subjected to a CLC process since the H2S content can be very high. In this work, a total of 41 h of continuous operation with acid gas and H2S concentrations up to 20 vol.% has been carried out in a 500 Wth CLC unit with two oxygen carriers based on Cu (Cu14γAl) and Fe (Fe20γAl). The formation of copper sulfides and the SO2 emissions in the air reactor made the Cu14γAl material not adequate for the process. In contrast, excellent results were obtained during acid gas combustion with the Fe20γAl oxygen carrier. H2S was fully burnt to SO2 in the fuel reactor at all operating conditions, SO2 was never detected in the gas outlet stream of the air reactor, and iron sulfides were never formed even at H2S concentrations as high as 20 vol.%. Furthermore, it was found that a H2S content of 20 vol.% in the acid gas was high enough to turn the CLC process into an auto-thermal process. Based on these results, it can be concluded that the Fe-based materials prepared by impregnation are very adequate to exploit

  10. An integrated approach for the evaluation of technological hazard impacts on air quality: the case of the Val d'Agri oil/gas plant

    Calvello, M.; Esposito, F.; Trippetta, S.

    2014-08-01

    The Val d'Agri area (southern Italy) hosts one of the biggest onshore European reservoir and the largest oil/gas pre-treatment plant, named Centro Olio Val d'Agri (COVA), located in a rural/anthropized context. Several hazards are associated with this plant. These are mainly represented by possible impacts of the COVA atmospheric emissions on the local air quality and human health. This work uses a novel approach based on the integration of air quality measurements from the regional monitoring network, additional experimental measurements (i.e. sub-micrometre particulate matter (PM1) and black carbon (BC)) and advanced statistical analyses to provide a preliminary evaluation of the Val d'Agri air quality state and give some indication of specific areas potentially affected by COVA hazards. Results show that the COVA plant emissions have a particular impact on the air quality of the area closest to it. In this area several pollutants specifically related to the COVA combustion processes (i.e. nitrogen oxides, benzene and toluene) show the highest concentration values and significant correlations. The proposed approach represents a first step in the assessment of the risks associated with oil/gas exploration and pre-treatment activities and a starting point for the development of effective and exportable air quality monitoring strategies.

  11. An integrated approach for the evaluation of technological hazard impacts on air quality: the case of the Val d'Agri oil/gas plant

    M. Calvello

    2014-04-01

    Full Text Available The Val d'Agri area (southern Italy hosts the biggest on-shore European reservoir and the largest oil/gas pre-treatment plant, named Centro Olio Val d'Agri (COVA, located in a rural/anthropized context. Several hazards are associated to this plant. These are mainly represented by possible impacts of the COVA atmospheric emissions on the local air quality and human health. This work uses a novel approach based on the integration of air quality measurements from the regional monitoring network, additional experimental measurements (i.e., sub-micrometric particulate matter – PM1 and Black Carbon – BC and advanced statistical analyses to provide a preliminary evaluation of the Val d'Agri air quality state and give some indications of specific areas potentially affected by COVA hazards. Results show that the COVA plant emissions exert an impact especially on the air quality of the area closest to it. In this area several pollutants specifically related to the COVA combustion processes (i.e., nitrogen oxides, benzene and toluene show the highest concentration values and significant correlations. The proposed approach represents a first step in the assessment of the risks associated to oil/gas exploration and pre-treatment activities and a starting point for the development of effective and exportable air quality monitoring strategies.

  12. Accident at chemically hazardous enterprises: numerical simulation of the process of neutralizing the toxic gas over the building roof

    N.N. Belyaev

    2012-04-01

    Full Text Available The 2D numerical model was used to simulate the toxic gas neutralization when this gas flows from the opening in the cellar of the building. The helicopter is used to supply the neutralizer. The model is based on the K-gradient transport model and equation of potential flow. The results of numerical experiment are presented.

  13. NUMERICAL SIMULATION OF WICKING TOXIC GAS INTO THE ROOM ON THE TERRITORY OF CHEMICALLY HAZARDOUS OBJECT DURING THE EMERGENCY

    N. N. Belyaev

    2010-11-01

    Full Text Available The 3D numerical model to simulate the toxic gas dispersion at an industrial site and inflow of toxic gas into the industrial room after an accident ejection was developed. The model is based on the K-gradient transport model and equation of potential flow. The results of numerical experiment are presented.

  14. Uptake of Gas-Phase Nitric Acid by Water-Ice Surfaces

    Ullerstam, M.; Abbatt, J. P.

    2004-05-01

    Nitric acid is a widespread molecule found in the atmosphere. It is mainly removed from the troposphere by wet or dry deposition. In colder regions such as the upper troposphere and tropopause where cirrus clouds are formed nitric acid can also be scavenged by cirrus ice particles. The uptake of gas-phase nitric acid by water-ice films has been re-examined with a coated-wall flow tube coupled to a chemical-ionization mass spectrometer (CIMS) at 228K. Previous flow tube studies of this system have shown little dependence of the uptake over the partial pressure regime studied. In these studies the initial, short-term uptake has been the focus and the long term uptake has not been quantified. In this experimental setup it was possible to study the uptake of nitric acid at lower partial pressures resulting in a more atmospherically appropriate determination of the adsorption isotherm and the long term uptake has also been addressed. Measurement of the initial uptake coefficient representing a lower limit will also be presented. Finally, possible burial of nitric acid into the bulk of the ice during continuous growth of the ice film has been studied. In the atmosphere ice particles will be subject to cycles of evaporation and condensation which could cause the nitric acid to be encapsulated into the particle, especially since the major part of the adsorption has been proven to be irreversible. This could enhance the ice particles capacity of scavenging nitric acid.

  15. Seismic hazard assessment for oil-and-gas-bearing shelf zones: A case study of the North Caspian region

    Krylov, A. A.; Ivashchenko, A. I.; Kovachev, S. A.

    2015-11-01

    Seismic hazard assessment is done for oil field areas in the North Caspian region by a method earlier successfully applied to other areas. The method involves general seismic zoning data, available regional databases on recurrence of seismic shaking, known models of ground motion attenuation in seismoactive regions, and data on geological and geophysical surveys in the studied area. The assigned level of seismic hazard of the region is refined using probabilistic analysis; additionally, disaggregation is made and accelerograms are synthesized (the latter are necessary for seismic microzoning of particular sites using the numerical nonlinear analysis of ground seismic response). The amplitude and spectral characteristics of ground motions are obtained which are necessary for seismic resistance design and construction of petroleum industry objects.

  16. 含硫化氢天然气泄漏事故的硫化氢中毒灾害分析%A new method for analyzing the hazardous hydrogen sulfide poisoning caused by the sulfurous natural gas leakage

    雷达; 张建文; 冯文兴

    2012-01-01

    应用前文建立的天然气长输管道泄漏扩散模型,在大量事故统计分析基础上,针对含硫化氢天然气泄漏后硫化氢导致的化学灾害后果提出了一种新的风险分析方法.综合考虑概率风险评价法和伤害范围评价法的特点,研究了不同规模泄漏事故可能导致的个人风险和社会风险,并绘制了相应的社会风险曲线图.%The present paper is aimed to introduce a new method for analyzing the hydrogen sulfide poisoning hazards caused by the sulfurous natural gas leakage. As is well known, China is rich in sulfurous natural gas, whose deposits are huge and widely distributed in our country. However, due to its toxic nature, the release of hydrogen sulfide-containing natural gas from the pipeline tends to bring about serious threats to human life and material property near its leakage source. To predict or evaluate the threat of hydrogen sulfide poisoning , a lot of measures can be taken to test or evaluate such hydrogen sulfide poisoning source, and QRA (Quantitative Hazard Analysis) method can be thought of as an effective one. But, the above said analysis method doesn t seem enough for the sake of security management of its exploration, letting alone to do the quantitative hazards, such as individual intake hazard and societal hazard, for ex- ample, the community poisoning threat. It is for this need that we would like to propose a new analysis method for hydrogen sulfide poisoning of hydrogen sulfide-bearing natural gas known as the comprehensive hazards analysis method, based on the study of the historical accident-statistical data of EGIG ( European Gas Pipeline Incident Data Group) and BG Transco, while the probability of hazard and the scope of the damage were taken into account. While working at our method, we have also analyzed the three leakage scenarios of the East-Sichuan Gas Transportation Project, including the individual hazard analysis and societal hazard analysis. In addition

  17. Electrons Mediate the Gas-Phase Oxidation of Formic Acid with Ozone.

    van der Linde, Christian; Tang, Wai-Kit; Siu, Chi-Kit; Beyer, Martin K

    2016-08-26

    Gas-phase reactions of CO3 (.-) with formic acid are studied using Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry. Signal loss indicates the release of a free electron, with the formation of neutral reaction products. This is corroborated by adding traces of SF6 to the reaction gas, which scavenges 38 % of the electrons. Quantum chemical calculations of the reaction potential energy surface provide a reaction path for the formation of neutral carbon dioxide and water as the thermochemically favored products. From the literature, it is known that free electrons in the troposphere attach to O2 , which in turn transfer the electron to O3 . O3 (.-) reacts with CO2 to form CO3 (.-) . The reaction reported here formally closes the catalytic cycle for the oxidation of formic acid with ozone, catalyzed by free electrons. PMID:27400953

  18. Prototype demonstration of dual sorbent injection for acid gas control on municipal solid waste combustion units

    None

    1994-05-01

    This report gathered and evaluated emissions and operations data associated with furnace injection of dry hydrated lime and duct injection of dry sodium bicarbonate at a commercial, 1500 ton per day, waste-to-energy facility. The information compiled during the project sheds light on these sorbents to affect acid gas emissions from municipal solid waste combustors. The information assesses the capability of these systems to meet the 1990 Clean Air Act and 1991 EPA Emission Guidelines.

  19. Evaluation and Management of the Gas and Rock Outburst Hazard in the Light of International Legal Regulations

    Skoczylas, Norbert; Wierzbicki, Mirosław

    2014-12-01

    As part of the present article, the Authors analyzed relevant legal rules that are in force in countries where the gas and coal outburst hazard occurs (Australia, the Czech Republic, China, Germany, Poland, Russia, and Ukraine). Similarities and differences between particular solutions were highlighted. As the subject of the analysis were the original legal standards, the article incorporates the parameter symbols and units adopted in the discussed regulations. W ramach niniejszej pracy poddano analizie obowiązujące rozwiązania prawne z krajów, gdzie występuje zagrożenie wyrzutami gazu i węgla (Australia, Czechy, Chiny, Niemcy, Polska, Rosja, Ukraina). Zwrócono uwagę na podobieństwa i różnice w poszczególnych rozwiązaniach. Ze względu na analizę oryginalnych rozwiązań legislacyjnych w opracowaniu pozostawione zostały stosowane w odpowiednich przepisach oznaczenia parametrów oraz ich jednostki. Istnieje duże podobieństwo w obrębie przepisów w krajach europejskich. Podobieństwo to dotyczy zarówno ogólnej koncepcji przepisów, w których dąży się do maksymalnego sformalizowania nakładanych wymogów, łącznie ze wskazaniem konkretnych parametrów górniczych oraz ich wartości kryterialnych, na bazie których klasyfikowane są pokłady węglowe, bądź ich części, do poszczególnych klas zagrożenia wyrzutowego. Podobne podejście w ustawodawstwie w zakresie bezpieczeństwa w górnictwie reprezentują Chiny. W całkowitej opozycji do przepisów europejskich i chińskich znajdują się przepisy amerykańskie i australijskie. W przepisach tych wyraźnie zaakcentowany jest fakt, iż charakter ryzyka wyrzutowego jest bardzo lokalny, więc trudno go uogólniać nie tylko między kopalniami, ale również w poszczególnych wyrobiskach. Jedno, niezmienne podejście do zarządzania ryzykiem, zgodnie z przepisami australijskimi, jest więc niewłaściwe. Przepisy te nie podają szczegółowego opisu, w jaki sposób prowadzić zarz

  20. A novel decomposition technique of friable asbestos by CHClF2-decomposed acidic gas

    Asbestos was widely used in numerous materials and building products due to their desirable properties. It is, however, well known that asbestos inhalation causes health damage and its inexpensive decomposition technique is necessary to be developed for pollution prevention. We report here an innovative decomposition technique of friable asbestos by acidic gas (HF and HCl) generated from the decomposition of CHClF2 by the reaction with superheated steam at 800 deg. C. Chrysotile-asbestos fibers were completely decomposed to sellaite and magnesium silicofluoride hexahydrate by the reaction with CHClF2-decomposed acidic gas at 150 deg. C for 30 min. At high temperatures beyond 400 deg. C, sellaite and hematite were detected in the decomposed product. In addition, crocidolite containing wastes and amosite containing wastes were decomposed at 500 deg. C and 600 deg. C for 30 min, respectively, by CHClF2-decomposed acidic gas. The observation of the reaction products by phase-contrast microscopy (PCM) and scanning electron microscopy (SEM) confirmed that the resulting products did not contain any asbestos

  1. Acetylsalicylic acid as a potential pediatric health hazard: legislative aspects concerning accidental intoxications in the European Union.

    Mund, Menen E; Gyo, Christoph; Brüggmann, Dörthe; Quarcoo, David; Groneberg, David A

    2016-01-01

    Acetylsalicylic acid is a frequently used medication worldwide. It is not used in pediatrics due its association with Reye syndrome. However, in case of pediatric intoxication, children are more fragile to salicylate poisoning because of their reduced ability of buffer the acid stress. Intoxication leads to a decoupling of oxidative phosphorylation and subsequently to a loss in mitochondrial function. Symptoms of poisoning are diverse; eventually they can lead to the death of the patient. Governmental websites of various EU countries were searched for legal information on acetylsalicylic acid availability in pharmacies and non-pharmacy stores. Various EU countries permit prescription-free sales of acetylsalicylic acid in pharmacies and non-pharmacy stores. In Sweden acetylsalicylic acid 500 mg may be sold in a maximum package size of 20 tablets or effervescent tablets in a non-pharmacy. In the UK a maximum of 16 tablets of acetylsalicylic acid 325 mg is allowed to sell in non-pharmacies. In Ireland acetylsalicylic acid is classified as S2 medication. Subsequently, acetylsalicylic acid is allowed to be sold prescription-free in pharmacies and non-pharmacy stores. In the Netherlands acetylsalicylic acid may only be sold in drug stores or pharmacies. A maximum of 24 tablets of 500 mg is allowed to purchase in a drug store. Several countries in the European Union are permitted to offer acetylsalicylic acid prescription-free in pharmacies and non-pharmacy stores without legal guidance on the storage position within the store. Further research is needed to investigate whether acetylsalicylic acid is located directly accessible to young children within the stores in EU countries which permit prescription-free sales of acetylsalicylic acid. PMID:27418941

  2. Analysis of the fatty acid composition of taraxicuum officinale flowers oil by gas chromatography mass spectrometer

    Taraxicum officinale, is a highly valuable medicinal plant. The roots is an important herbal drug, having long been used on the continent as a remedy for liver complaints. Keeping in view the importance and wide applications in the pharmaceutical industries, the present study was therefore aimed to analyze the chemical constituents of the flowers of T. officinale. The T. officinale flowers oil constituents of methyl ester derivatives of fatty acids were analyzed applying gas chromatography coupled to mass spectrometer. The results obtained showed the presence of both containing the saturated as well as unsaturated fatty acids in T. officinale flower oils. A total of 19 different components were identified and quantified. The concentration level of Methyl ester of Lenolenic acid was found very effective in concentration 3.33%, among the identified analytes of interest. In addition, the level of other chemical constituents of methyl ester of palmitic acid 3.11%, myristic acid 1.87, linolenic acids 1.67%, stearic acid 0.97 were found. The concentration level of the rest of identified fatty acids analytes were below 1%. Thus the results obtained from the current initiative is very promising due to the presence of high percentage of valuable analytes concentrations recorded in the fatty acid of T. officinale flower oil. Thus due to the presence of highly important analytes which have increased their importance for consumption in the pharmaceuticals as well as its applications in the new formulations for different skin, cosmetics and health purposes and for use by local practioners. The study will also provide a scientific database line. (author)

  3. Determination of major phenolic acids, phenolic diterpenes and triterpenes in Rosemary (Rosmarinus Officinalis L.) by gas chromatography and mass spectrometry:

    Vončina, Ernest; Doleček, Valter; Islamčević Razboršek, Maša; Brodnjak-Vončina, Darinka

    2007-01-01

    A gas chromatographic-mass spectrometric (GC-MS) method for the simultaneous identification and quantification of seven major phenolic and terpenic compounds in Rosmarinus officinalis L. was developed. The compounds were identified as trimethylsilyl (TMS) derivatives of phenolic acids (caffeic and rosmarinic acid), phenolic diterpene (carnosic acid), and pentacyclic triterpenes (ursolic, oleanolic, betulinic acid and betulin). These compounds have been identified by retention time and compari...

  4. Rapid Detection of Gas Hazards and Leaks with an Atmospheric Sampling, High Resolution, Mass Spectrometer with Low Pumping Requirements Project

    National Aeronautics and Space Administration — Miniaturization of mass spectrometers is restricted almost exclusively by the ability of small vacuum pumps to remove gas loads during operation of the instrument....

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

    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.

  6. Determination of long-chain fatty acids in serum by gas chromatography coupled to mass spectrometry

    The quantification of long-chain fatty acids is fundamental for the diagnosis of several peroxisome disorders, particularly those in which the β-oxidation peroxisome of fatty acids is affected. In this work the implementation of an analytical method for the determination of these markers in serum by gas chromatography coupled to mass spectrometry is described. Besides, samples from patients with a diagnostic impression of adrenoleukodystrophy linked to the X chromosome were analyzed. The necessary experimental conditions were achieved for the separation and quantification of C22:0, C24:0 and C26:0 fatty acids in serum, which are biochemical markers of various peroxisome diseases. The application of this method allowed confirming the diagnosis of three patients with a diagnostic impression of adrenoleukodystrophy linked to the X chromosome. The application of the method in daily practice will allow the Cuban medical system to count on a new laboratory parameter for the diagnosis of peroxisome disorders

  7. Effect of dimethylamine on the gas phase sulfuric acid concentration measured by Chemical Ionization Mass Spectrometry

    Rondo, L.; Ehrhart, S.; Kürten, A.; Adamov, A.; Bianchi, F.; Breitenlechner, M.; Duplissy, J.; Franchin, A.; Dommen, J.; Donahue, N. M.; Dunne, E. M.; Flagan, R. C.; Hakala, J.; Hansel, A.; Keskinen, H.; Kim, J.; Jokinen, T.; Lehtipalo, K.; Leiminger, M.; Praplan, A.; Riccobono, F.; Rissanen, M. P.; Sarnela, N.; Schobesberger, S.; Simon, M.; Sipilä, M.; Smith, J. N.; Tomé, A.; Tröstl, J.; Tsagkogeorgas, G.; Vaattovaara, P.; Winkler, P. M.; Williamson, C.; Wimmer, D.; Baltensperger, U.; Kirkby, J.; Kulmala, M.; Petäjä, T.; Worsnop, D. R.; Curtius, J.

    2016-03-01

    Sulfuric acid is widely recognized as a very important substance driving atmospheric aerosol nucleation. Based on quantum chemical calculations it has been suggested that the quantitative detection of gas phase sulfuric acid (H2SO4) by use of Chemical Ionization Mass Spectrometry (CIMS) could be biased in the presence of gas phase amines such as dimethylamine (DMA). An experiment (CLOUD7 campaign) was set up at the CLOUD (Cosmics Leaving OUtdoor Droplets) chamber to investigate the quantitative detection of H2SO4 in the presence of dimethylamine by CIMS at atmospherically relevant concentrations. For the first time in the CLOUD experiment, the monomer sulfuric acid concentration was measured by a CIMS and by two CI-APi-TOF (Chemical Ionization-Atmospheric Pressure interface-Time Of Flight) mass spectrometers. In addition, neutral sulfuric acid clusters were measured with the CI-APi-TOFs. The CLOUD7 measurements show that in the presence of dimethylamine (<5 to 70 pptv) the sulfuric acid monomer measured by the CIMS represents only a fraction of the total H2SO4, contained in the monomer and the clusters that is available for particle growth. Although it was found that the addition of dimethylamine dramatically changes the H2SO4 cluster distribution compared to binary (H2SO4-H2O) conditions, the CIMS detection efficiency does not seem to depend substantially on whether an individual H2SO4 monomer is clustered with a DMA molecule. The experimental observations are supported by numerical simulations based on A Self-contained Atmospheric chemistry coDe coupled with a molecular process model (Sulfuric Acid Water NUCleation) operated in the kinetic limit.

  8. Comparison of the composition and gas/particle partitioning of organic acids in monoterpene and isoprene dominated environments

    Thompson, S.; Yatavelli, L. R.; Stark, H.; Kimmel, J.; Krechmer, J.; Hu, W.; Palm, B. B.; Campuzano Jost, P.; Day, D. A.; Isaacman, G. A.; Goldstein, A. H.; Khan, M. H.; Holzinger, R.; Lopez-Hilfiker, F.; Mohr, C.; Thornton, J. A.; Jayne, J. T.; Worsnop, D. R.; Jimenez, J. L.

    2013-12-01

    Gas and particle-phase organic acids measurements from two different regions with different biogenic volatile organic compound emissions are used to understand gas/particle partitioning principles. A Chemical Ionization High Resolution Time-of-Flight Mass Spectrometer (HRToF-CIMS), with acetate (CH3COO-) as the reagent ion was used to selectively detect acids. Hundreds of gas and particle-phase organic acids were measured in both locations, a monoterpene and MBO-dominated environment (ponderosa pine forest in Colorado, BEACHON-RoMBAS 2011) and isoprene and terpene-dominated environment (mixed deciduous and pine forest in Alabama, SOAS 2013). Time series of gas/particle partitioning for ions consistent with tracers for isoprene oxidation such as methacrylic acid epoxide (MAE) and isoprene epoxydiol (IEPOX) and tracers for α-pinene oxidation such as pinic and pinonic acid will be presented. Gas/particle partitioning, represented as the fraction of each species in the particle-phase, Fp, was calculated for C1-C18 alkanoic acids and biogenic VOC oxidation tracers and compared to an absorptive partitioning model. These results are compared with those of two other instruments that can also quantify gas/particle partitioning with high time resolution: a Semivolatile Thermal Desorption Aerosol GC/MS (SV-TAG) and a Thermal Desorption Proton Transfer Time-of-Flight Mass Spectrometer (TD-PTRMS). Data from both environments were consistent with the values and trends predicted by the absorptive partitioning model for the tracer acids. However, for low carbon number alkanoic acids we report a higher fraction in the particle phase than predicted by the model. The Fp for the bulk-averaged acids and its relationship to the degree of oxidation and carbon number will also be presented. Temporal patterns and correlations with atmospheric conditions and composition will be explored for individual and bulk acids. We will discuss atmospheric implications of the gas/particle partitioning

  9. Formation of Small Gas Phase Carbonyls from Heterogeneous Oxidation of Polyunsaturated Fatty Acids (PUFA)

    Zhou, S.; Zhao, R.; Lee, A.; Gao, S.; Abbatt, J.

    2011-12-01

    Fatty acids (FAs) are emitted into the atmosphere from gas and diesel powered vehicles, cooking, plants, and marine biota. Field measurements have suggested that FAs, including polyunsaturated fatty acids (PUFA), could make up an important contribution to the organic fraction of atmospheric aerosols. Due to the existence of carbon-carbon double bonds in their molecules, PUFA are believed to be highly reactive towards atmospheric oxidants such as OH and NO3 radicals and ozone, which will contribute to aerosol hygroscopicity and cloud condensation nuclei activity. Previous work from our group has shown that small carbonyls formed from the heterogeneous reaction of linoleic acid (LA) thin films with gas-phase O3. It is known that the formation of small carbonyls in the atmosphere is not only relevant to the atmospheric budget of volatile organic compounds but also to secondary organic aerosol formation. In the present study, using an online proton transfer reaction mass spectrometry (PTR-MS) and off-line gas chromatography-mass spectrometry (GC-MS) we again investigated carbonyl formation from the same reaction system, i.e. the heterogeneous ozonolysis of LA film. In addition to the previously reported carbonyls, malondialdehyde (MDA), a source of reactive oxygen species that is mutagenic, has been identified as a product for the first time. Small dicarbonyls, e.g. glyoxal, are expected to be formed from the further oxidation of MDA. In this presentation, the gas-phase chemistry of MDA with OH radicals using a newly built Teflon chamber in our group will also be presented.

  10. Analysis of tert-butyldimethylsilyl derivatives in heavy gas oil from Brazilian naphthenic acids by gas chromatography coupled to mass spectrometry with electron impact ionization.

    Vaz de Campos, Maria Cecília; Oliveira, Eniz Conceição; Filho, Pedro José Sanches; Piatnicki, Clarisse Maria Sartori; Caramão, Elina Bastos

    2006-02-10

    Naphthenic acids, C(n)H(2n+Z)O(2), are a complex mixture of alkyl-substituted acyclic and cycle-aliphatic carboxylic acids. The content of naphthenic acids and their derivatives in crude oils is very small, which hinders their extraction from matrixes of wide and varied composition. In this work, liquid-liquid extraction, followed by solid phase extraction with an ion exchange resin (Amberlyst A-27) and ultrasound desorption were used to isolate the acid fraction from heavy gas oil of Marlim petroleum (Campos, Rio de Janeiro, Brazil). The analysis was accomplished through gas chromatography coupled to mass spectrometry with electron impact ionization, after derivatization with N-methyl-N-(tert-butyldimethylsilyl)trifluoracetamide (MTBDMSTFA). The results indicate the presence of carboxylic acids belonging to families of alicyclic and naphthenic compounds which contain up to four rings in the molecule. PMID:16439253

  11. 78 FR 53190 - Pipeline Safety: Notice to Operators of Hazardous Liquid and Natural Gas Pipelines of a Recall on...

    2013-08-28

    ... Liquid and Natural Gas Pipelines of a Recall on Leak Repair Clamps Due to Defective Seal AGENCY: Pipeline.... Williamson, Inc. (TDW) Leak Repair Clamp (LRC) recall issued by TDW on June 17, 2013. The recall covers all... subject to the recall by reviewing their records and equipment for installation of these LRCs....

  12. Determination of 4-Chloroindole-3-Acetic Acid Methyl Ester in Lathyrus Vicia and Pisum by Gas Chromatography - Mass Spectrometry

    Engvild, Kjeld Christensen; Egsgaard, Helge; Larsen, Elfinn

    1980-01-01

    methyl ester isomers. The quantitative determination of 4-chloroindole-3-acetic acid methyl ester in immature seeds of these three species was performed by gas chromatography – mass spectrometry using deuterium labelled 4-chloro-indole-3-acetic acid methyl ester as an internal standard. P. sativum...

  13. Identification and hazard prediction of tattoo pigments by means of pyrolysis—gas chromatography/mass spectrometry

    Schreiver, Ines; Hutzler, Christoph; Andree, Sarah; Laux, Peter; Luch, Andreas

    2016-01-01

    The implementation of regulation for tattoo ink ingredients across Europe has generated the need for analytical methods suitable to identify prohibited compounds. Common challenges of this subject are the poor solubility and the lack of volatility for most pigments and polymers applied in tattoo inks. Here, we present pyrolysis coupled to online gas chromatography and electron impact ionization mass spectrometry (py-GC/MS) as quick and reliable tool for pigment identification using both purif...

  14. Analysis of Gas Permeability Characteristics of Poly(Lactic Acid)/Poly(Butylene Succinate) Nanocomposites

    Amita Bhatia; Rahul K Gupta; Bhattacharya, Sati N.; Hyoung Jin Choi

    2012-01-01

    Gas permeability and morphological properties of nanocomposites prepared by the mixing of poly(lactic acid) (PLA), poly(butylene succinate) (PBS), and clay was investigated. While the composition of PLA and PBS polymers was fixed as 80% and 20% by weight, respectively, for all the nanocomposites, clay contents varied from 1 to 10 wt%. From the morphological studies using both wide angle X-ray diffraction and transmission electron microscopy, the nanocomposite having 1 wt% of clay was consider...

  15. The microbial communities and potential greenhouse gas production in boreal acid sulphate, non-acid sulphate, and reedy sulphidic soils

    Acid sulphate (AS) soils along the Baltic coasts contain significant amounts of organic carbon and nitrogen in their subsoils. The abundance, composition, and activity of microbial communities throughout the AS soil profile were analysed. The data from a drained AS soil were compared with those from a drained non-AS soil and a pristine wetland soil from the same region. Moreover, the potential production of methane, carbon dioxide, and nitrous oxide from the soils was determined under laboratory conditions. Direct microscopic counting, glucose-induced respiration (GIR), whole cell hybridisation, and extended phospholipid fatty acid (PLFA) analysis confirmed the presence of abundant microbial communities in the topsoil and also in the deepest Cg2 horizon of the AS soil. The patterns of microbial counts, biomass and activity in the profile of the AS soil and partly also in the non-AS soil therefore differed from the general tendency of gradual decreases in soil profiles. High respiration in the deepest Cg2 horizon of the AS soil (5.66 μg C g− 1 h− 1, as compared to 2.71 μg C g− 1 h− 1 in a top Ap horizon) is unusual but reasonable given the large amount of organic carbon in this horizon. Nitrous oxide production peaked in the BCgc horizon of the AS and in the BC horizon of the non-AS soil, but the peak value was ten-fold higher in the AS soil than in the non-AS soil (82.3 vs. 8.6 ng N g− 1d− 1). The data suggest that boreal AS soils on the Baltic coast contain high microbial abundance and activity. This, together with the abundant carbon and total and mineral nitrogen in the deep layers of AS soils, may result in substantial gas production. Consequently, high GHG emissions could occur, for example, when the generally high water table is lowered because of arable farming. - Highlights: •Boreal acid sulphate soils contain large amounts of organic C and N in subsoils. •Microbial communities throughout the acid sulphate soil profile were analysed.

  16. Gas emission from diffuse degassing structures (DDS) of the Cameroon volcanic line (CVL): Implications for the prevention of CO2-related hazards

    Issa; Ohba, T.; Chako Tchamabé, B.; Padrón, E.; Hernández, P.; Eneke Takem, E. G.; Barrancos, J.; Sighomnoun, D.; Ooki, S.; Nkamdjou, Sigha; Kusakabe, M.; Yoshida, Y.; Dionis, S.

    2014-08-01

    In the mid-1980s, lakes Nyos and Monoun violently released massive gas, mainly magmatic CO2 killing about 1800 people. Subsequent geochemical surveys and social studies indicate that lakes Nyos and Monoun event is cyclic in nature and may occur anywhere in the about 37 other volcanic lakes located in the corridor of the Cameroon volcanic line (CVL). This potential threat motivated us to check if, alike Nyos and Monoun, the internal dynamic of the other lakes is also controlled by inputs of deep-seated-derived CO2 and attempt to measure and provide comprehensive insights on the passive gas emission along the CVL. This knowledge shall contribute to the prevention of volcanic lake-related hazards in Cameroon and the refinement of the Global Carbon Cycle. We used in situ fixation and dry gas phase sampling methods to determine CO2 origin and the concentration, and the accumulation chamber technique to measure diffuse CO2 emission from nine lakes and on soil at Nyos Valley and Mount Manenguba Caldera. The results suggest that, although in minor concentrations (compared to Nyos and Monoun), ranging from 0.56 mmol kg- 1 to 8.75 mmol kg- 1, the bottom waters of some lakes also contain measurable magmatic CO2 with δ13C varies from - 4.42‰ to - 9.16‰ vs. PDB. That finding implies that, under certain circumstances, e.g. increase to volcanic and/or tectonic activities along the CVL, the concerned lakes could develop a Nyos-type behavioural scheme. The diffuse gas emission results indicate that the nine surveyed lakes release approximately 3.69 ± 0.37 kt km- 2 yr- 1 of CO2 to the atmosphere; extrapolation to the approximately 39 volcanic lakes located on the CVL yields an approximate CO2 output of 27.37 ± 0.5 kt km- 2 yr- 1, representing 0.023% of the global CO2 output from volcanic lakes. In addition to the precedent value, the gas removal operation in lakes Nyos and Monoun released approximately 2.52 ± 0.46 × 108 mol km- 2 yr- 1 CO2 to the atmosphere from January

  17. Core acid treatment influence on well reservoir properties in Kazan oil-gas condensate field

    Janishevskii, A.; Ezhova, A.

    2015-11-01

    The research involves investigation of the influence of hydrochloric acid (HCI-12%) and mud acid (mixture: HCl - 10% and HF - 3%) treatment on the Upper-Jurassic reservoir properties in Kazan oil-gas condensate field wells. The sample collection included three lots of core cylinders from one and the same depth (all in all 42). Two lots of core cylinders were distributed as following: first lot - reservoir properties were determined, and, then thin sections were cut off from cylinder faces; second lot- core cylinders were exposed to hydrochloric acid treatment, then, after flushing the reservoir properties were determined, and thin sections were prepared. Based on the quantitative petrographic rock analysis, involvin 42 thin sections, the following factors were determined: granulometric mineral composition, cement content, intergranular contacts and pore space structure. According to the comparative analysis of initial samples, the following was determined: content decrease of feldspar, clay and mica fragments, mica, clay and carbonate cement; increase of pore spaces while in the investigated samples- on exposure of rocks to acids effective porosity and permeability value range is ambiguous.

  18. Inhibition of methane and natural gas hydrate formation by altering the structure of water with amino acids.

    Sa, Jeong-Hoon; Kwak, Gye-Hoon; Han, Kunwoo; Ahn, Docheon; Cho, Seong Jun; Lee, Ju Dong; Lee, Kun-Hong

    2016-01-01

    Natural gas hydrates are solid hydrogen-bonded water crystals containing small molecular gases. The amount of natural gas stored as hydrates in permafrost and ocean sediments is twice that of all other fossil fuels combined. However, hydrate blockages also hinder oil/gas pipeline transportation, and, despite their huge potential as energy sources, our insufficient understanding of hydrates has limited their extraction. Here, we report how the presence of amino acids in water induces changes in its structure and thus interrupts the formation of methane and natural gas hydrates. The perturbation of the structure of water by amino acids and the resulting selective inhibition of hydrate cage formation were observed directly. A strong correlation was found between the inhibition efficiencies of amino acids and their physicochemical properties, which demonstrates the importance of their direct interactions with water and the resulting dissolution environment. The inhibition of methane and natural gas hydrate formation by amino acids has the potential to be highly beneficial in practical applications such as hydrate exploitation, oil/gas transportation, and flow assurance. Further, the interactions between amino acids and water are essential to the equilibria and dynamics of many physical, chemical, biological, and environmental processes. PMID:27526869

  19. Modeling acid-gas injection in deep saline aquifers for geological sequestration. Paper no. IGEC-1-070

    Geological sequestration of acid gas (H2S and CO2, with minor traces of hydrocarbons) is an important strategy for reducing release of greenhouse gases and sulfur compounds to the atmosphere. Performance of a deep well injection operation during and after injection is critically dependent on the physical and chemical properties of the injected gases, the operational parameters such as injection rate and pressure, as well as the geological and geochemical properties of the formation. This paper presents a semi-analytical model to predict the injection well performance as a function of these parameters for geological sequestration. In this model, in-situ phase and thermodynamic properties of acid gases are calculated by using volume-shifted Peng-Robinson equation of state and combining rules for mixtures. Equations governing the radial injection and migration of an immiscible acid gas into confined aquifers, its flow around the injector and toward the top due to buoyancy with simultaneous dissolution, and the escape of gases through leakage are presented. The formation heterogeneity and formation damage around the wellbore due to drilling, completion or mineral trapping are also considered. It has shown that the both formation characteristics and operational characteristics have significant influences on the underground migration, distribution and the total volume of the acid gas sequestrated. By evaluation of the well injectivity, this model provides a basic framework for planning and designing acid gas deep well injection process and hence the maximum allowable limits on acid gas geological sequestration. (author)

  20. Measurement of arachidonic acid release from human polymorphonuclear neutrophils and platelets: comparison between gas chromatographic and radiometric assays

    a simple gas chromatographic method for the assay of phospholipase A2 (PLA2) has been described in which arachidonic acid released from endogenous phospholipid pools is measured following its extraction and derivatization to pentafluorobenzyl esters. Using this assay, PLA2 activities in control and calcium ionophore-stimulated human neutrophils, as well as in control, thrombin, and calcium ionophore stimulated human platelets, have been measured. These values are compared with those obtained by monitoring the release of radioactivity from 3H- or 14Carachidonic acid prelabeled cells. While the radiometric assay measures only the release of exogenously incorporated radioactive arachidonic acid, the gas chromatographic assay measures arachidonic acid released from all the endogenous pools. Thus, the apparent increase in PLA2 activity in stimulated cells measured by the gas chromatographic assay is four- to fivefold higher than that by the radiometric assay. Inclusion of fatty acid free bovine serum albumin in the reaction buffer significantly increases the amount of arachidonic acid that is measured by gas chromatography. The gas chromatographic method has also been successfully utilized for measuring PLA2 activity in cell-free preparations derived from physically disrupted human neutrophils

  1. Transportation of hazardous goods

    TS Department

    2008-01-01

    A general reminder: any transportation of hazardous goods by road is subject to the European ADR rules. The goods concerned are essentially the following: Explosive substances and objects; Gases (including aerosols and non-flammable gases such as helium and nitrogen); Flammable substances and liquids (inks, paints, resins, petroleum products, alcohols, acetone, thinners); Toxic substances (acids, thinners); Radioactive substances; Corrosive substances (paints, acids, caustic products, disinfectants, electrical batteries). Any requests for the transport of hazardous goods must be executed in compliance with the instructions given at this URL: http://ts-dep.web.cern.ch/ts-dep/groups/he/HH/adr.pdf Heavy Handling Section TS-HE-HH 73793 - 160364

  2. Gas-Phase Amidation of Carboxylic Acids with Woodward's Reagent K Ions

    Peng, Zhou; Pilo, Alice L.; Luongo, Carl A.; McLuckey, Scott A.

    2015-06-01

    Gas-phase amidation of carboxylic acids in multiply-charged peptides is demonstrated via ion/ion reactions with Woodward's reagent K (wrk) in both positive and negative mode. Woodward's reagent K, N-ethyl-3-phenylisoxazolium-3'-sulfonate, is a commonly used reagent that activates carboxylates to form amide bonds with amines in solution. Here, we demonstrate that the analogous gas-phase chemistry occurs upon reaction of the wrk ions and doubly protonated (or doubly deprotonated) peptide ions containing the carboxylic acid functionality. The reaction involves the formation of the enol ester intermediate in the electrostatic complex. Upon collisional activation, the ethyl amine on the reagent is transferred to the activated carbonyl carbon on the peptide, resulting in the formation of an ethyl amide (addition of 27 Da to the peptide) with loss of a neutral ketene derivative. Further collision-induced dissociation (CID) of the products and comparison with solution-phase amidation product confirms the structure of the ethyl amide.

  3. Evaluation of a gas chromatography method for azelaic acid determination in selected biological samples

    Mahdi Garelnabi

    2010-09-01

    Full Text Available Background: Azelaic acid (AzA is the best known dicarboxilic acid to have pharmaceutical benefits and clinical applications and also to be associated with some diseases pathophysiology. Materials and Methods: We extracted and methylesterified AzA and determined its concentration in human plasma obtained from healthy individuals and also in mice fed AzA containing diet for three months. Results: AzA was detected in Gas Chromatography (GC and confirmed by Liquid chromatography mass spectrometry (LCMS, and gas chromatography mass spectrometry (GCMC. Our results have shown that AzA can be determined efficiently in selected biological samples by GC method with 1nM limit of detection (LoD and the limit of quantification (LoQ; was established at 50nM. Analytical Sensitivity as assayed by hexane demonstrated an analytical sensitivity at 0.050nM. The method has demonstrated 8-10% CV batch repeatability across the sample types and 13-18.9% CV for the Within-Lab Precision analysis. The method has shown that AzA can efficiently be recovered from various sample preparation including liver tissue homogenate (95% and human plasma (97%. Conclusions: Because of its simplicity and lower limit of quantification, the present method provides a useful tool for determining AzA in various biological sample preparations.

  4. Barrow hazards survey

    Following a series of public meetings at which PERG presented the results of a literature review and site specific accident study of the hazards of the maritime transport of spent nuclear reactor fuel to Barrow (en route to the Windscale reprocessing works), PERG was requested by the Planning Committee of Barrow Town Council to prepare an assessment of the interaction of the hazards arising from the concentration of nuclear activities in the area with those of a proposed gas-terminal. This report presents a preliminary review of the Environmental Impact Assessments prepared by the Borough Surveyor and a critical appraisal of the hazard analyses undertaken by the Health and Safety Executive, and the consultants to Cumbria County Council on this matter, the Safety and Reliability Directorate of the United Kingdom Atomic Energy Authority. After a general and historical introduction, the document continues under the following headings: a description of the hazards (BNFL spent fuel shipments; the gas terminal; gas condensate storage; the Vickers shipyard (involving nuclear powered submarines)); the interaction of hazards; planning implications and democratic decisions; recommendations. (U.K.)

  5. Influence of liquid and gas flow rates on sulfuric acid mist removal from air by packed bed tower

    Jafari Mohammad Javad

    2012-12-01

    Full Text Available Abstract The possible emission of sulfuric acid mists from a laboratory scale, counter-current packed bed tower operated with a caustic scrubbing solution was studied. Acid mists were applied through a local exhaust hood. The emissions from the packed bed tower were monitored in three different categories of gas flow rate as well as three liquid flow rates, while other influencing parameters were kept almost constant. Air sampling and sulfuric acid measurement were carried out iso-kinetically using USEPA method 8. The acid mists were measured by the barium-thorin titration method. According to the results when the gas flow rate increased from 10 L/s to 30 L/s, the average removal efficiency increased significantly (p 3, respectively. L/G of 2–3 was recommended for designing purposes of a packed tower for sulfuric acid mists and vapors removal from contaminated air stream.

  6. Influence of Liquid and Gas Flow Rates on Sulfuric acid Mist removal from Air by Packed bed Tower

    Mohammad Javad Jafari

    2012-12-01

    Full Text Available The possible emission of sulfuric acid mists from a laboratory scale, counter-current packed bed tower operated with a caustic scrubbing solution was studied. Acid mists were applied through a local exhaust hood. The emissions from the packed bed tower were monitored in three different categories of gas flow rate as well as threeliquid flow rates, while other influencing paramet ers were kept almost constant. Air sampling and sulfuric acid measurement were carried out iso-kinetically using USEPA method 8. The acid mists were measured by the barium-thorin titration method. According to the results when the gas flow rate increased from 10 L/s to 30 L/s,the average removal efficiency increased significantly (p 3, respectively. L/G of 2–3 was recommended for designing purposes of a packed tower for sulfuric acid mists and vapors removal from contaminated air stream.

  7. Analysis of phenolic acids as chloroformate derivatives using solid phase microextraction-gas chromatography.

    Citová, Ivana; Sladkovský, Radek; Solich, Petr

    2006-07-28

    In the presented study, a simple and original procedure of phenolic acids derivatization treated by ethyl and methyl chloroformate performed in an aqueous media consisting of acetonitrile, water, methanol/ethanol and pyridine has been modified and optimized. Seven phenolic acid standards-caffeic, ferulic, gallic, p-coumaric, protocatechuic, syringic and vanillic were derivatized into corresponding methyl/ethyl esters and subsequently determined by the means of gas chromatography connected to the flame-ionisation detector (FID). Some selected validation parameters as linearity, detection and quantitation limits and peak area repeatability were valued. The total time of gas chromatography (GC) analysis was 24 min for methyl chloroformate and 30 min for ethyl chloroformate derivatization. The more suitable methyl chloroformate derivatization was used for further experiments on the possibility of multiple pre-concentration by the direct solid phase microextraction technique (SPME). For this purpose, polyacrylate (PA), polydimethylsiloxane (PDMS), carboxen/polydimethylsiloxane (CAR/PDMS) and polydimethylsiloxane/divinylbenzene (PDMS/DVB) fibres were tested and the extraction conditions concerning time of extraction, temperature and time of desorption were optimized. The most polar PA fibre gave the best results under optimal extraction conditions (50 min extraction time, 25 degrees C extraction temperature and 10 min desorption time). As a result, the total time of SPME-GC analysis was 74 min and an increase in method sensitivity was reached. The limits of quantitation (LOQ) of p-coumaric, ferulic, syringic and vanillic acid esters after SPME pre-concentration were 0.02, 0.17, 0.2 and 0.2 microg mL(-1), respectively, showing approximately 10 times higher sensitivity in comparison with the original GC method. PMID:17723529

  8. Acid decomposition and thiourea leaching of silver from hazardous jarosite residues: Effect of some cations on the stability of the thiourea system.

    Calla-Choque, D; Nava-Alonso, F; Fuentes-Aceituno, J C

    2016-11-01

    The recovery of silver from hazardous jarosite residues was studied employing thiourea as leaching agent at acid pH and 90°C. The stability of the thiourea in synthetic solutions was evaluated in the presence of some cations that can be present in this leaching system: cupric and ferric ions as oxidant species, and zinc, lead and iron as divalent ions. Two silver leaching methods were studied: the simultaneous jarosite decomposition-silver leaching, and the jarosite decomposition followed by the silver leaching. The study with synthetic solutions demonstrated that cupric and ferric ions have a negative effect on thiourea stability due to their oxidant properties. The effect of cupric ions is more significant than the effect of ferric ions; other studied cations (Fe(2+), Zn(2+), Pb(2+)) had no effect on the stability of thiourea. When the decomposition of jarosite and the silver leaching are carried out simultaneously, 70% of the silver can be recovered. When the acid decomposition was performed at pH 0.5 followed by the leaching step at pH 1, total silver recovery increased up to 90%. The zinc is completely dissolved with any of these processes while the lead is practically insoluble with these systems producing a lead-rich residue. PMID:27322901

  9. A comparative investigation on adsorption performances of mesoporous activated carbon prepared from waste rubber tire and activated carbon for a hazardous azo dye-Acid Blue 113

    Research highlights: → The system is cheap, efficient and fast for the removal of dyes from waters. → Higher adsorption capacity is due to higher mesoporous volume of the adsorbent. → The rate determining step of the adsorption process is particle diffusion. - Abstract: A mesoporous carbon developed from waste tire rubber, characterized by chemical analysis, FTIR, and SEM studies, was used as an adsorbent for the removal and recovery of a hazardous azo dye, Acid Blue 113. Surface area, porosity, and density were determined. The adsorption of the dye over the prepared adsorbent and a commercial activated carbon was achieved under different pH, adsorbate concentration, sieve size, adsorbent dosage, contact time and temperature conditions. Langmuir and Freundlich adsorption isotherm models were applied and thermodynamic parameters were calculated. Kinetic studies indicated that the adsorption process follow first order kinetics and particle diffusion mechanisms are operative. By percolating the dye solution through fixed-bed columns the bulk removal of the Acid Blue 113 was carried out and necessary parameters were determined to find out the percentage saturation of both the columns. Recovery of the dye was made by eluting 0.1 M NaOH through the column.

  10. A validated method for gas chromatographic analysis of gamma-aminobutyric acid in tall fescue herbage.

    Kagan, Isabelle A; Coe, Brenda L; Smith, Lori L; Huo, Cheng-Jun; Dougherty, Charles T; Strickland, James R

    2008-07-23

    Gamma-aminobutyric acid (GABA) is an inhibitory neurotransmitter in animals that is also found in plants and has been associated with plant responses to stress. A simple and relatively rapid method of GABA separation and quantification was developed from a commercially available kit for serum amino acids (Phenomenex EZ:faast) and validated for tall fescue (Festuca arundinacea). Extraction in ethanol/water (80:20, v/v) at ambient temperature yielded detectable amounts of GABA. Clean separation from other amino acids in 28 min was achieved by gas chromatography (GC) with flame ionization detection (FID), using a 30 m, 5% phenyl/95% dimethylpolysiloxane column. The identity of the putative GABA peak was confirmed by GC with mass spectrometric (MS) detection. The relatively small effects of the sample matrix on GABA measurement were verified by demonstrating slope parallelism of GABA curves prepared in the presence and absence of fescue extracts. Limits of quantification and detection were 2.00 and 1.00 nmol/100 microL, respectively. Method recoveries at two different spike levels were 96.4 and 94.2%, with coefficients of variation of 7.3 and 7.2%, respectively. PMID:18558696

  11. The effect of zeolite treatment by acids on sodium adsorption ratio of coal seam gas water.

    Wang, Xiaoyu; Ozdemir, Orhan; Hampton, Marc A; Nguyen, Anh V; Do, Duong D

    2012-10-15

    Many coal seam gas (CSG) waters contain a sodium ion concentration which is too high relative to calcium and magnesium ions for environment acceptance. Natural zeolites can be used as a cheap and effective method to control sodium adsorption ratio (SAR, which is a measure of the relative preponderance of sodium to calcium and magnesium) due to its high cation exchange capacity. In this study, a natural zeolite from Queensland was examined for its potential to treat CSG water to remove sodium ions to lower SAR and reduce the pH value. The results demonstrate that acid activated zeolite at 30%wt solid ratio can reduce the sodium content from 563.0 to 182.7 ppm; the pH from 8.74 to 6.95; and SAR from 70.3 to 18.5. Based on the results of the batch experiments, the sodium adsorption capacity of the acid-treated zeolite is three times greater than that of the untreated zeolite. Both the untreated and acid-treated zeolite samples were characterized using zeta potential, surface characterization, DTA/TG and particle size distribution in order to explain their adsorption behaviours. PMID:22841594

  12. Bio-toxicological supervision op workers exposed to lead poisoning hazard. Systematic examination of amino acids, in urine and plasma

    A bio-toxicological chart was established for the workers in a firm handling lead. The known facts concerning professional lead poisoning are outlined, after which the importance of lead work in a nuclear center is discussed. The work station of each man is described and the results of analyses made during atmospheric checks on the site are given with sampling techniques. Since the biological chart is centered on the chromatographic exploration of amino acids in blood and urine, the analytical technique used is described and the different technical modifications made to the standard technique reported. The results obtained on reference subjects are compared with those found in the specialized literature. The results found in lead workers are then presented in the form of histograms, which better illustrate the differences observed with respect to the reference subjects. An hematological and toxicological balance-sheet is drawn up and the correlation existing between the results of coproporphyrine, lead and delta-aminolevulinic acid analyses in urine is checked. Biological detection of lead-poisoning has the advantage of providing an early diagnosis, thus enabling the works doctor to forestall the effects of this professional disease before any clinical symptoms appear. (author)

  13. Oil/gas pre-treatment plants and air quality hazards: PM1 measurements in Agri Valley (southern Italy)

    Trippetta, S.; Caggiano, R.; Sabia, S.

    2014-04-01

    A PM1 (i.e., aerosol particles with aerodynamic diameter less 1.0 μm) short term monitoring campaign was carried out in Agri Valley (southern Italy) in September 2012. This area is of international concern since it houses the largest European on-shore reservoir and the largest oil/gas pre-treatment plant (i.e., Centro Olio Val d'Agri - COVA) within an anthropized context. PM1 measurements were performed in Viggiano, the nearest town to the COVA plant and one of the most populated town of the Agri Valley. During the study period, the PM1 daily concentrations ranged from 1.2 to 8.4 μg m-3 with a mean value of 4.6 μg m-3. Regarding the PM1 chemical composition, it can be observed that S and typical crustal elements were the most abundant constituents of the PM1 collected. By applying the Principal Component Analysis, it was pointed out that crustal soil, biomass and wood burning, secondary atmospheric reactions involving COVA plant emissions and local soil particles, and traffic were the main sources contributing to the PM1 measured in the area under study. Moreover, a possible contribution of the long-range transport of African dust was observed.

  14. Identification and hazard prediction of tattoo pigments by means of pyrolysis-gas chromatography/mass spectrometry.

    Schreiver, Ines; Hutzler, Christoph; Andree, Sarah; Laux, Peter; Luch, Andreas

    2016-07-01

    The implementation of regulation for tattoo ink ingredients across Europe has generated the need for analytical methods suitable to identify prohibited compounds. Common challenges of this subject are the poor solubility and the lack of volatility for most pigments and polymers applied in tattoo inks. Here, we present pyrolysis coupled to online gas chromatography and electron impact ionization mass spectrometry (py-GC/MS) as quick and reliable tool for pigment identification using both purified pigments and tattoo ink formulations. Some 36 organic pigments frequently used in tattoo inks were subjected to py-GC/MS with the aim to establish a pyrogram library. To cross-validate pigment identification, 28 commercially available tattoo inks as well as 18 self-made pigment mixtures were analyzed. Pyrograms of inks and mixtures were evaluated by two different means to work out the most reliable and fastest strategy for an otherwise rather time-consuming data review. Using this approach, the declaration of tattoo pigments currently used on the market could be verified. The pyrolysis library presented here is also assumed suitable to predict decomposition patterns of pigments when affected by other degradation scenarios, such as sunlight exposure or laser irradiation. Thus, the consumers' risk associated with the exposure to toxicologically relevant substances that originate from pigment decomposition in the dermal layers of the skin can be assessed. Differentiation between more or less harmful pigments for this field of application now will become feasible. PMID:27209489

  15. Heating cells in acid methanol for 30 min without freeze-drying provides adequate yields of fatty acids and alcohols for gas chromatographic characterization of mycobacteria.

    Jimenez, J; Larsson, L

    1986-01-01

    We studied the release of mycobacterial fatty acids (as methyl esters) and secondary alcohols after heating both wet and freeze-dried cells in methanolic hydrogen chloride for different time periods. A 30-min heating of the mycobacteria without prior freeze-drying was found adequate in a routine gas chromatographic procedure for strain and species characterization.

  16. Formation of 3-methyl-1,2,3-butanetricarboxylic acid via gas phase oxidation of pinonic acid – a mass spectrometric study of SOA aging

    L. Müller

    2011-07-01

    Full Text Available This paper presents the results of mass spectrometric investigations of the OH-initiated oxidative aging of α-pinene SOA under simulated tropospheric conditions at the large aerosol chamber facility AIDA, Karlsruhe Institute of Technology. In particular, the OH-initiated oxidation of pure pinic and pinonic acid, two well-known oxidation products of α-pinene, was investigated. Two complementary analytical techniques were used, on-line atmospheric pressure chemical ionization/mass spectrometry (APCI/MS and filter sampling followed by liquid chromatography/mass spectrometry (LC/ESI-MS. The results show that 3-methyl-1,2,3-butanetricarboxylic acid (MBTCA, a known and very low volatile α-pinene SOA product, is formed from the oxidation of pinonic acid and that this oxidation takes place in the gas phase. This finding is confirmed by temperature-dependent aging experiments on whole SOA formed from α-pinene, in which the yield of MBTCA scales with the pinonic acid fraction in the gas phase. Based on the results, several feasible gas-phase radical mechanisms are discussed to explain the formation of MBTCA from OH-initiated pinonic acid oxidation.

  17. Formation of 3-methyl-1,2,3-butanetricarboxylic acid via gas phase oxidation of pinonic acid - a mass spectrometric study of SOA aging

    Müller, L.; Reinnig, M.-C.; Naumann, K. H.; Saathoff, H.; Mentel, T. F.; Donahue, N. M.; Hoffmann, T.

    2012-02-01

    This paper presents the results of mass spectrometric investigations of the OH-initiated oxidative aging of α-pinene SOA under simulated tropospheric conditions at the large aerosol chamber facility AIDA, Karlsruhe Institute of Technology. In particular, the OH-initiated oxidation of pure pinic and pinonic acid, two well-known oxidation products of α-pinene, was investigated. Two complementary analytical techniques were used, on-line atmospheric pressure chemical ionization/mass spectrometry (APCI/MS) and filter sampling followed by liquid chromatography/mass spectrometry (LC/ESI-MS). The results show that 3-methyl-1,2,3-butanetricarboxylic acid (MBTCA), a very low volatile α-pinene SOA product and a tracer compound for terpene SOA, is formed from the oxidation of pinonic acid and that this oxidation takes place in the gas phase. This finding is confirmed by temperature-dependent aging experiments on whole SOA formed from α-pinene, in which the yield of MBTCA scales with the pinonic acid fraction in the gas phase. Based on the results, several feasible gas-phase radical mechanisms are discussed to explain the formation of MBTCA from OH-initiated pinonic acid oxidation.

  18. Effect of peat quality on microbial greenhouse gas formation in an acidic fen

    M. Reiche

    2009-09-01

    Full Text Available Peatlands play an important role in the global carbon cycle and represent both an important stock of soil carbon and a substantial natural source of relevant greenhouse gases like CO2 and CH4. While it is known that the microbial availability of organic matter affects degradation and mineralization processes in peatlands, the manner in which peat organic matter affects the formation of CO2 and CH4 remains unclear. In this study we developed a fast and simple peat quality index in order to estimate its greenhouse gas potential by linking the thermo-degradability of peat with anaerobic CO2 and CH4 formation rates. Peat samples were obtained at several depths (0–40 cm at four sampling locations from an acidic fen (pH∼4.7. CO2 and CH4 formation rates were highly spatially variable and depended on depth, sampling location, and the composition of pyrolysable organic matter. Peat samples active in CO2 and CH4 formation had a quality index above 1.35, and the fraction of thermally labile pyrolyzable organic matter (comparable to easily available carbon substrates for microbial activity obtained by thermogravimetry was above 35%. Curie-point pyrolysis-gas chromatography/mass spectrometry mainly identified carbohydrates and lignin as pyrolysis products in these samples, indicating that undecomposed organic matter was found in this fraction. In contrast, lipids and unspecific pyrolysis products, which indicate recalcitrant and highly decomposed organic matter, correlated significantly with lower CO2 formation and reduced methanogenesis. Our results suggest that undecomposed organic matter is a prerequisite for CH4 and CO2 development in acidic fens. Furthermore, the new peat quality index should aide the estimation of greenhouse gas formation potential resulting from peatland restoration and permafrost thawing

  19. Study on removal of elemental mercury from simulated flue gas over activated coke treated by acid

    Ma, Jinfeng [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082 (China); Li, Caiting, E-mail: ctli@hnu.edu.cn [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082 (China); Zhao, Lingkui; Zhang, Jie; Song, Jingke; Zeng, Guangming; Zhang, Xunan; Xie, Yine [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082 (China)

    2015-02-28

    Highlights: • HClO{sub 4} treated AC was developed for effective Hg{sup 0} removal from simulated flue gas. • The exceptional effect of SO{sub 2} on Hg{sup 0} removal by AC{sub 4.5} was discussed. • Possible reaction mechanism of Hg{sup 0} removal over AC{sub 4.5} was put forward. - Abstract: This work addressed the investigation of activated coke (AC) treated by acids. Effects of AC samples, modified by ether different acids (H{sub 2}SO{sub 4}, HNO{sub 3} and HClO{sub 4}) or HClO{sub 4} of varied concentrations, on Hg{sup 0} removal were studied under simulated flue gas conditions. In addition, effects of reaction temperature and individual flue gas components including O{sub 2}, NO, SO{sub 2} and H{sub 2}O were discussed. In the experiments, Brunauer–Emmett–Teller (BET), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) were applied to explore the surface properties of sorbents and possible mechanism of Hg{sup 0} oxidation. Results showed that AC sample treated by HClO{sub 4} of 4.5 mol/L exhibited maximum promotion of efficiency on Hg{sup 0} removal at 160 °C. NO was proved to be positive in the removal of Hg{sup 0}. And SO{sub 2} displayed varied impact in capturing Hg{sup 0} due to the integrated reactions between SO{sub 2} and modified AC. The addition of O{sub 2} could improve the advancement further to some extent. Besides, the Hg{sup 0} removal capacity had a slight declination when H{sub 2}O was added in gas flow. Based on the analysis of XPS and FTIR, the selected sample absorbed Hg{sup 0} mostly in chemical way. The reaction mechanism, deduced from results of characterization and performance of AC samples, indicated that Hg{sup 0} could firstly be absorbed on sorbent and then react with oxygen-containing (C−O) or chlorine-containing groups (C−Cl) on the surface of sorbent. And the products were mainly in forms of mercuric chloride (HgCl{sub 2}) and mercuric oxide (HgO)

  20. Advanced Acid Gas Separation Technology for Clean Power and Syngas Applications

    Amy, Fabrice [Air Products and Chemicals Inc., Allentown, PA (United States); Hufton, Jeffrey [Air Products and Chemicals Inc., Allentown, PA (United States); Bhadra, Shubhra [Air Products and Chemicals Inc., Allentown, PA (United States); Weist, Edward [Air Products and Chemicals Inc., Allentown, PA (United States); Lau, Garret [Air Products and Chemicals Inc., Allentown, PA (United States); Jonas, Gordon [Air Products and Chemicals Inc., Allentown, PA (United States)

    2015-06-30

    Air Products has developed an acid gas removal technology based on adsorption (Sour PSA) that favorably compares with incumbent AGR technologies. During this DOE-sponsored study, Air Products has been able to increase the Sour PSA technology readiness level by successfully operating a two-bed test system on coal-derived sour syngas at the NCCC, validating the lifetime and performance of the adsorbent material. Both proprietary simulation and data obtained during the testing at NCCC were used to further refine the estimate of the performance of the Sour PSA technology when expanded to a commercial scale. In-house experiments on sweet syngas combined with simulation work allowed Air Products to develop new PSA cycles that allowed for further reduction in capital expenditure. Finally our techno economic analysis of the use the Sour PSA technology for both IGCC and coal-to-methanol applications suggests significant improvement of the unit cost of electricity and methanol compared to incumbent AGR technologies.

  1. Incorporation of small BN domains in graphene during CVD using methane, boric acid and nitrogen gas.

    Bepete, George; Voiry, Damien; Chhowalla, Manish; Chiguvare, Zivayi; Coville, Neil J

    2013-07-21

    Chemical doping of graphene with small boron nitride (BN) domains has been shown to be an effective way of permanently modulating the electronic properties in graphene. Herein we show a facile method of growing large area graphene doped with small BN domains on copper foils using a single step CVD route with methane, boric acid powder and nitrogen gas as the carbon, boron and nitrogen sources respectively. This facile and safe process avoids the use of boranes and ammonia. Optical microscopy confirmed that continuous films were grown and Raman spectroscopy confirmed changes in the electronic structure of the grown BN doped graphene. Using XPS studies we find that both B and N can be substituted into the graphene structure in the form of small BN domains to give a B-N-C system. A novel structure for the BN doped graphene is proposed. PMID:23759928

  2. Incorporation of small BN domains in graphene during CVD using methane, boric acid and nitrogen gas

    Bepete, George; Voiry, Damien; Chhowalla, Manish; Chiguvare, Zivayi; Coville, Neil J.

    2013-06-01

    Chemical doping of graphene with small boron nitride (BN) domains has been shown to be an effective way of permanently modulating the electronic properties in graphene. Herein we show a facile method of growing large area graphene doped with small BN domains on copper foils using a single step CVD route with methane, boric acid powder and nitrogen gas as the carbon, boron and nitrogen sources respectively. This facile and safe process avoids the use of boranes and ammonia. Optical microscopy confirmed that continuous films were grown and Raman spectroscopy confirmed changes in the electronic structure of the grown BN doped graphene. Using XPS studies we find that both B and N can be substituted into the graphene structure in the form of small BN domains to give a B-N-C system. A novel structure for the BN doped graphene is proposed.

  3. Analysis of dibutylphosphoric acid (DBP) in degraded solvent by utilizing gas chromatograph-mass spectrometry

    In JAEA, a washing process of tributylphosphate (TBP) in the Purex reprocessing have been investigated by means of n-butylamine oxalate as a washing reagent, which is decomposable by incineration or electrolysis. The concentration of the dibutylphosphoric acid (DBP) in organic and aqueous phase has been determined by an ion-chromatography. In this analytical method, however; we found out that the quantitative analysis for DBP exhibited poor reproducibility because of low sensitivity for DBP. Here we report a new analytical method for DBP by means of a gas chromatograph-mass spectrometry (GC-MS). From our investigation, silylation of DBP was efficient to improve the sensitivity and the reproducibility of the quantitative analysis for DBP. Moreover, we found out that the silylation was effective for the analysis of monobutylphosphoric (MBP). (author)

  4. Infrared and density functional theory studies of formic acid hydrate clusters in noble gas matrices

    Ito, Fumiyuki

    2016-08-01

    Infrared absorption spectra of formic acid hydrate clusters (HCOOH)m(H2O)n have been measured in noble gas matrices (Ar and Kr). The concentration dependence of the spectra and the comparison with a previous experimental study on HCOOH(H2O) and HCOOH(H2O)2 [Geoge et al., Spectrochim. Acta, Part A 60 (2004) 3225] led to the identification of large clusters. Density functional theory calculations at the B3LYP-DCP/6-31+G(2d,2p) level were carried out to determine the anharmonic vibrational properties of the clusters, enabling a consistent assignment of the observed vibrational peaks to specific clusters.

  5. Multi-coincidence measurements in gas-phase amino acid alanine after valence level ionization

    Full text: The first chiral amino acids having distinct enantiomeric structures is the alanine. Therefore the study of such molecules is important for developing our understanding of this class of molecule. In this work, we report coincidence measurements between photoelectron and photoion, and total ion yield (TIY) measurements after valence level ionization of D,L-alanine in gas phase. The experiments were performed at the Brazilian Synchrotron Light Source (LNLS) at the Toroidal Grating Monochromator beamline (D0-5A TGM) in the 12-35 eV energy range. The end-station of the beamline is composed by a time-of-flight (TOF) spectrometer specially build for the photoelectron-photoion-photoion (PEPIPICO) measurements. The TIY have been compared with valence photoelectron spectra recorded with synchrotron radiation reported in the literature and have been discussed in a comparative form. The results will be presented during the conference

  6. Fundamental studies of acid gas treating by aqueous alkanolamines: Vapor-liquid equilibrium studies. Annual report, January-December 1992

    Ng, H.J.; Huang, S.H.

    1993-02-01

    The project addresses the measurement of the solubilities of acid gases such as H2S and CO2 in alkanolamine solutions. Systems of acid gas mixtures and of amine mixtures are included in the study. The temperature range extended from 40 to 120 C and the partial pressure of the acid gases ranged from 0.005 kPa up to 3,000 kPa. The range is sufficient to cover most of the industrial operating conditions for amine-based sweeteners. The planned schedule of experimental work was maintained during 1992. The solubilities of H2S in seven amine systems have been measured and reported. The study will be continued in 1993. The measurements will be extended to systems containing CO2 as the acid gas.

  7. Hazardous waste to materials: recovery of molybdenum and vanadium from acidic leach liquor of spent hydroprocessing catalyst using alamine 308.

    Sahu, K K; Agrawal, Archana; Mishra, D

    2013-08-15

    Recovery of valuable materials/metals from waste goes hand in hand with environmental protection. This paper deals with the development of a process for the recovery of metals such as Mo, V, Ni, Al from spent hydroprocessing catalyst which may otherwise cause a nuisance if dumped untreated. A detailed study on the separation of molybdenum and vanadium from the leach solution of spent hydroprocessing catalyst of composition: 27.15% MoO₃, 1.7% V₂O₅, 3.75% NiO, 54.3% Al₂O₃, 2.3% SiO₂ and 10.4% LOI is reported in this paper. The catalyst was subjected to roasting under oxidizing atmosphere at a temperature of about 550 °C and leaching in dilute sulphuric acid to dissolve molybdenum, vanadium, nickel and part of aluminium. Metals from the leach solution were separated by solvent extraction. Both molybdenum and vanadium were selectively extracted with a suitable organic solvent leaving nickel and dissolved aluminium in the raffinate. Various parameters such as initial pH of the aqueous feed, organic to aqueous ratio (O:A), solvent concentration etc. were optimized for the complete extraction and recovery of Mo and V. Molybdenum and vanadium from the loaded organic were stripped by ammonia solution. They were recovered as their corresponding ammonium salt by selective precipitation, and were further calcined to get the corresponding oxides in pure form. PMID:23644591

  8. Aspects on the removal of hazardous substances from flue gas by the applicance of waste water treatment techniques. Final report. Abwassertechnische Aspekte bei der Schadstoffreduzierung aus Abgasen. Schlussbericht

    Dreschmann, P.; Sterk, T.

    1988-01-01

    The objective of this investigation was the qualitative and quantitative assessment of condensates, the examination of changes to the characteristics of the waste water due to immission of condensates, the assessment of effects on communal waste water purification plants, the investigation of the possibilities of waste gas purification using communal waste water. The results of investigations have shown that discharge of untreated condensates will not be possible, with respect to local regulations, as the pH value of the condensates vary between 3.0 and 4.0 in the case of gas-firing, and between 1.7 and 2.5 in the case of oil-firing. As far as the other approximate values given by the ATV in the worksheet A 115 'Advice on discharging waste water into public sewage works' are concerned, for anions, cations and hydrocarbons, it was possible to demonstrate that such values were not exceeded in the case of gas condensates, whereas in the gas of oil condensates, depending on the furnace installation, values were at times exceeded. The discharge experiments, conducted with various mixtures of condensate/waste water, have shown that the neutralisation of condensates using communal waste water, depending on the furnace installation and the fuel used, is definitely capable of being implemented as a pretreatment technique. In order to prevent damage to the biocenosis and to guarantee nitrification in the waste water purification plant, an acidic capacity in the flow of k/sub S/ /sub 43/ /ge/ 6.5 mmol/l is required. Trials in waste gas purification using communal waste water of the City of Heidenheim produced elimination rates, in the case of oil-firing, for SO/sub 2/ of eta SO/sub 2/ = 88.1% with an inlet facility in the channel floor, and of eta SO/sub 2/ = 97.4% with a countercurrent cascade. In the case of gas-firing an NO/sub x/ elimination rate of eta NO/sub x/ = 12.8% was achieved. 133 refs., 48 tabs., 45 figs.

  9. Structural characterization of humic acids, extracted from sewage sludge during composting, by thermochemolysis–gas chromatography–mass spectrometry

    Amir, Soumia; Hafidi, Mohamed; Lemee, Laurent; Merlina, Georges; Guiresse, Maritxu; Pinelli, Eric; Revel, Jean-Claude; Bailly, Jean-René; Amblès, André

    2006-01-01

    Thermochemolysis coupled with gas chromatography and mass spectrometry were applied to determine the structure of humic acids (HA) extracted from a sewage sludge and straw mixture at different steps of composting. The HA extracted from sludge mixture released various compounds, such as mono-, di-, tri-methoxy (alkyl) benzene and (alkyl) benzoic acids, which originated from lignin like derivatives of phydroxyphenyl, guiaicyl and syringyl units. In addition, other aromatic non-lignin derived st...

  10. The tropospheric processing of acidic gases and hydrogen sulphide in volcanic gas plumes as inferred from field and model investigations

    Aiuppa, A.; Franco, A.; von Glasow, R.; Allen, A.G.; W. D'Alessandro; Mather, T. A.; Pyle, D. M.; Valenza, M.

    2007-01-01

    Improving the constraints on the atmospheric fate and depletion rates of acidic compounds persistently emitted by non-erupting (quiescent) volcanoes is important for quantitatively predicting the environmental impact of volcanic gas plumes. Here, we present new experimental data coupled with modelling studies to investigate the chemical processing of acidic volcanogenic species during tropospheric dispersion. Diffusive tube samplers were deployed at Mount Etna, a very active open-conduit basa...

  11. The tropospheric processing of acidic gases and hydrogen sulphide in volcanic gas plumes as inferred from field and model investigations

    Aiuppa, A.; Franco, A.; von Glasow, R.; Allen, A.G.; D’Alessandro, W.; Mather, T. A.; Pyle, D. M.; Valenza, M.

    2006-01-01

    Improving the constraints on the atmospheric fate and depletion rates of acidic compounds persistently emitted by non-erupting (quiescent) volcanoes is important for quantitatively predicting the environmental impact of volcanic gas plumes. Here, we present new experimental data coupled with modelling studies to investigate the chemical processing of acidic volcanogenic species during tropospheric dispersion. Diffusive tube samplers were deployed at Mount Etna, a very active open-conduit basa...

  12. Observations of gas phase hydrochloric acid in the polluted marine boundary layer

    Crisp, Timia A.; Lerner, Brian M.; Williams, Eric J.; Quinn, Patricia K.; Bates, Timothy S.; Bertram, Timothy H.

    2014-06-01

    Ship-based measurements of gas phase hydrochloric acid (HCl), particulate chloride (pCl-), and reactive nitrogen oxides (NOy) were made in the polluted marine boundary layer along the California coastline during spring 2010. These observations are used to assess both the rate of Cl atom production from HCl and the role of direct HCl emissions and subsequent partitioning as a source for pCl-. Observations of HCl made in coastal Southern California are broadly correlated with NOz (NOz ≡ NOy - NOx), peaking at 11 A.M. The observed median HCl mixing ratio in Southern California is 1.3 ppb (interquartile range: 0.53-2.7 ppb), as compared to 0.19 ppb (interquartile range: 0.10-0.38 ppb) measured along the Sacramento River between San Francisco and Sacramento. Concurrent measurements of aerosol ion chemistry indicate that aerosol particles sampled in Northern California are heavily depleted in Cl-, corresponding to a mean pCl- deficit of 0.05 ± 0.03 (1σ) ppb for sub-10 µm aerosol particles. In comparison, aerosols measured in Southern California indicate that over 25% of particles showed an addition of Cl- to the particle population. Observations presented here suggest that primary sources of HCl, or gas phase chlorine precursors to HCl, are likely underestimated in the California Air Resource Board emissions inventory. These results highlight the need for future field observations designed to better constrain direct reactive halogen emissions.

  13. Utilization of multiple waste streams for acid gas sequestration and multi-pollutant control

    Soong, Y.; Dilmore, R.M.; Hedges, S.W.; Howard, B.H.; Romanov, V. [U.S. Department of Energy, National Energy Technology Laboratory, Pittsburgh, PA (United States)

    2012-03-15

    A novel CO{sub 2} sequestration concept is reported that combines SO{sub 2} removal and CO{sub 2} capture and sequestration, using a bauxite-processing residue which is a waste product and with waste brine water from oil/gas production. The bauxite residue/brine mixture of 46/54 v/v exhibited a CO{sub 2} sequestration capacity of > 0.078 mol L{sup -1} when exposed to pure CO{sub 2} at 20 C and 2.73 MPa. At a higher temperature of 140 C, a bauxite residue/brine mixture of 80/20 v/v indicated a CO{sub 2} sequestration capacity of > 0.094 mol L{sup -1} when exposed to pure CO{sub 2} at 3.85 MPa. Under the same reaction conditions, an identical ratio of reaction mixture exposed to simulated flue gas at a similar initial pressure was capable of sequestering 0.16 mol of CO{sub 2} and > 99.9 % of the applied SO{sub 2}. Calcite formation was verified as a product of bauxite/brine mixture carbonation. The caustic bauxite residues (pH 12.5-13.5) and acidic wastewater brine (pH 3-5) are also effectively neutralized after participating as reactive reagents in the conceptual process. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  14. Analysis of Gas Permeability Characteristics of Poly(Lactic Acid/Poly(Butylene Succinate Nanocomposites

    Amita Bhatia

    2012-01-01

    Full Text Available Gas permeability and morphological properties of nanocomposites prepared by the mixing of poly(lactic acid (PLA, poly(butylene succinate (PBS, and clay was investigated. While the composition of PLA and PBS polymers was fixed as 80% and 20% by weight, respectively, for all the nanocomposites, clay contents varied from 1 to 10 wt%. From the morphological studies using both wide angle X-ray diffraction and transmission electron microscopy, the nanocomposite having 1 wt% of clay was considered to have a mixed morphology of intercalated and delaminated structure, while some clusters or agglomerated particles were detected for nanocomposites having 3 and more than 3 wt% of clay content. However, the average particle size of the dispersed PBS phase was reduced significantly from 7 μm to 30–40 nm with the addition of clay in the blend. The oxygen barrier property was improved significantly as compared to the water vapor. A model based on gas barrier property was used for the validation of the oxygen relative permeabilities of PLA/PBS/clay nanocomposites. PLA/PBS/clay nanocomposites validated the Bharadwaj model up to 3 wt% of clay contents only, while for nanocomposites of higher clay contents the Bharadwaj model was invalid due to the clusters and agglomerates formed.

  15. Gas-Phase Thermal Tautomerization of Imidazole-Acetic Acid: Theoretical and Computational Investigations

    Saadullah G. Aziz

    2015-11-01

    Full Text Available The gas-phase thermal tautomerization reaction between imidazole-4-acetic (I and imidazole-5-acetic (II acids was monitored using the traditional hybrid functional (B3LYP and the long-range corrected functionals (CAM-B3LYP and ωB97XD with 6-311++G** and aug-cc-pvdz basis sets. The roles of the long-range and dispersion corrections on their geometrical parameters, thermodynamic functions, kinetics, dipole moments, Highest Occupied Molecular Orbital–Lowest Unoccupied Molecular Orbital (HOMO–LUMO energy gaps and total hyperpolarizability were investigated. All tested levels of theory predicted the preference of I over II by 0.750–0.877 kcal/mol. The origin of predilection of I is assigned to the H-bonding interaction (nN8→σ*O14–H15. This interaction stabilized I by 15.07 kcal/mol. The gas-phase interconversion between the two tautomers assumed a 1,2-proton shift mechanism, with two transition states (TS, TS1 and TS2, having energy barriers of 47.67–49.92 and 49.55–52.69 kcal/mol, respectively, and an sp3-type intermediate. A water-assisted 1,3-proton shift route brought the barrier height down to less than 20 kcal/mol in gas-phase and less than 12 kcal/mol in solution. The relatively high values of total hyperpolarizability of I compared to II were interpreted and discussed.

  16. Transparent nanocellulosic multilayer thin films on polylactic acid with tunable gas barrier properties.

    Aulin, Christian; Karabulut, Erdem; Tran, Amy; Wågberg, Lars; Lindström, Tom

    2013-08-14

    The layer-by-layer (LbL) deposition method was used for the build-up of alternating layers of nanofibrillated cellulose (NFC) or carboxymethyl cellulose (CMC) with a branched, cationic polyelectrolyte, polyethyleneimine (PEI) on flexible poly (lactic acid) (PLA) substrates. With this procedure, optically transparent nanocellulosic films with tunable gas barrier properties were formed. 50 layer pairs of PEI/NFC and PEI/CMC deposited on PLA have oxygen permeabilities of 0.34 and 0.71 cm(3)·μm/m(2)·day·kPa at 23 °C and 50% relative humidity, respectively, which is in the same range as polyvinyl alcohol and ethylene vinyl alcohol. The oxygen permeability of these multilayer nanocomposites outperforms those of pure NFC films prepared by solvent-casting. The nanocellulosic LbL assemblies on PLA substrates was in detailed characterized using a quartz crystal microbalance with dissipation (QCM-D). Atomic force microscopy (AFM) reveals large structural differences between the PEI/NFC and the PEI/CMC assemblies, with the PEI/NFC assembly showing a highly entangled network of nanofibrils, whereas the PEI/CMC surfaces lacked structural features. Scanning electron microscopy images showed a nearly perfect uniformity of the nanocellulosic coatings on PLA, and light transmittance results revealed remarkable transparency of the LbL-coated PLA films. The present work demonstrates the first ever LbL films based on high aspect ratio, water-dispersible nanofibrillated cellulose, and water-soluble carboxymethyl cellulose polymers that can be used as multifunctional films and coatings with tailorable properties, such as gas barriers and transparency. Owing to its flexibility, transparency and high-performance gas barrier properties, these thin film assemblies are promising candidates for several large-scale applications, including flexible electronics and renewable packaging. PMID:23834391

  17. Validation of an enantioselective analysis for (l)-pidolic acid by chiral gas chromatography with derivatization.

    Salisbury, John J; Li, Mingshu; Boyd, Aisha

    2016-02-20

    A sensitive and rapid analytical method has been validated for the enantiomeric purity determination of l-pidolic acid, a biological lactam and metabolite of glutamic acid commonly found in urine, skin, bones, brain and is available commercially as a food supplement. An efficient, two-step achiral derivatization was implemented which consisted of an alkylation step (using HCl-IPA) followed by an acylation step (using TFAA) of the carboxy and amide functional groups. This allowed detection with high sensitivity using gas chromatography with flame ionization detection. The described procedure employs a CP-Chiralsil-L Val column (25m×0.25mm) at a constant flow rate of 1.5mLmin(-1), a gradient temperature program from 80°C to 160°C and an injector and detector temperature of 250°C. The proposed method was validated according to ICH Q2 standards and included such parameters as specificity, system precision, analyst repeatability, intermediate precision, accuracy, linearity, LOD/LOQ and solution stability. PMID:26710173

  18. Determination of methacrylic acid in food simulants by pyrolytic butylation-gas chromatography.

    Huang, Zhongping; Qiu, Ruofeng; Liu, Tingfei; Huang, Yilei; Zhu, Zuoyi; Wang, Lili

    2016-07-01

    An on-line pyrolytic butylation approach was proposed to determine methacrylic acid (MA) in food simulants by gas chromatography (GC) without an expensive pyrolyzer. MA in food simulants was converted into butyl methacrylate in the presence of tetrabutylammonium hydroxide (TBAH) without any pretreatment at 330°C in the injection-port, contributing to high GC signal response. The derivatizing conditions for the proposed method were optimized, namely the injection-port temperature, type and amount of the organic alkaline used for derivatization. A series of standard solutions of MA in the range of 1.0-50mg/kg were analyzed with correlation coefficient r≥0.9975. The limits of detection (LODs) were less than 0.15mg/kg for MA in four matrix simulants (distilled water, 3%w/v acetic acid, 10%v/v ethanol, and isooctane). Relative standard deviations (RSDs) for retention time, peak height and peak area were all less than 3.88%. The technique was successfully applied to the analysis of MA migrating from plastic cup samples, with recoveries of added MA in the range of 96.5-123.0%. Direct injection of the simulants into the GC system after migration tests, without any pretreatment step, makes the developed method of great value for rapid screening analysis of samples in bulks. PMID:27262371

  19. Novel derivatization technique for the detection of phenoxyacetic acid herbicides by gas chromatography-mass spectrometry

    Complete text of publication follows. The analytical detection of phenoxyacetic acid type herbicides (2,4-D, dichloprop, MCPA, etc.) from environmental samples is often a problem in instrumental analysis, as these compounds containing free carboxylic groups require chemical derivatisation prior to gas chromatographic (GC) methods. Commonly used derivatising agents include diazomethane and pentachlorobenzyl bromide, the former being toxic and explosive, the latter is being most suitable for GC with electron capture detector. In order to detect these compounds in GC coupled with mass spectrometry (GC-MS), a novel method for the formation of stable chemical derivatives from the acidic herbicides prior to GC analysis was developed. Earlier we have applied silylcarbamates for the derivatisation of chlorophenols (A. Kovacs et al., J. Chromat. A, 1194 (1) (2008) 139-142.), and this procedure was extended now to the silylation of phenoxyacetic acid type compounds. We studied the reactions between commercially available trimethylsilyl N,N-dimethylcarbamate and mecoprop, MCPA, dichlorprop, 2,4-D, MCPB 2,4,5-T, 2,4,5-TP and 2,4-DB, respectively. Beside the trimethylsilylated derivatives of the target compounds the corresponding tert-butyldimethylsilyl derivatives were also prepared in order to enhance hydrolytic stability and improve mass spectrometric properties. For that purpose the corresponding tert-butyldimethylsilyl N,N-dimethylcarbamate agent was prepared, allowing detection limits at ppb level. The reactions proved to be fast and the reagent excess and by-products were proven not to interfere with the target compounds. In accordance with the expectations tert-butyldimethylsilyl esters of phenoxyacetic acids surpassed the corresponding trimethylsilyl analogues both in stability and detectability. The procedure was also compared with the results obtained by commercial silylating agent BSTFA and certain alkylating agents (TMAH, Me3SOH, trimethylsilyldiazomethane

  20. Flue gas desulfurization by-product weathering by acidic mine drainage

    The authors examined the suitability using a flue gas desulfurization grout (FGDG) for the attenuation and abatement of acidic mine drainage (AMD). The FGDG used was a mixture of fly ash (FA) and filter cake (FC) with a FA/FC ratio of 1:1 to improve handling. Five percent of lime (CaO) was added to improve strength development and allow the use of this FGDG as a hydrologic seal for underground mines. Acidic mine drainage solutions collect from wells located within mine voids were reacted with samples of FGDG for up to 168 d, to evaluate the potential for grout dissolution subsequent to subterranean implacement. Shortly upon reaction with AMD, FGDG released a number of ions into solution (As, B, Ca, K, Na, Se, SO4), a concomitant with a rapid increase in solution pH (8.5), causing decreases in the solubility of most cations (Al, Fe, Mn, Zn). Significant increases in dissolved As and B concentrations were noted. Both elements were present in solution at levels below respective regulatory limits for drinking water. Of the original quantities of As and B present in FGDG, 1.3 and 45.6%, respectively, were released to solution over a 168-d reaction period. Concomitant with changes in solution composition, reaction of FGDG with AMD resulted in a loss of ettringite and hannebachgite and a growth of gypsum. Additional changes in mineralogy were observed as FGDG equilibrated with AMD solutions. From these reactions, the long-term stability of FGDG in underground acidic mine environments is questionable and warrants study in situ

  1. Strontium isotope quantification of siderite, brine and acid mine drainage contributions to abandoned gas well discharges in the Appalachian Plateau

    Chapman, Elizabeth C. [Univ. of Pittsburgh, PA (United States). Dept. of Geology and Planetary Science; Capo, Rosemary C. [Univ. of Pittsburgh, PA (United States). Dept. of Geology and Planetary Science; Stewart, Brian W. [Univ. of Pittsburgh, PA (United States). Dept. of Geology and Planetary Science; Hedin, Robert S. [Hedin Environmental, Pittsburgh, PA (United States); Weaver, Theodore J. [Hedin Environmental, Pittsburgh, PA (United States); Edenborn, Harry M. [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States)

    2013-04-01

    Unplugged abandoned oil and gas wells in the Appalachian region can serve as conduits for the movement of waters impacted by fossil fuel extraction. Strontium isotope and geochemical analysis indicate that artesian discharges of water with high total dissolved solids (TDS) from a series of gas wells in western Pennsylvania result from the infiltration of acidic, low Fe (Fe < 10 mg/L) coal mine drainage (AMD) into shallow, siderite (iron carbonate)-cemented sandstone aquifers. The acidity from the AMD promotes dissolution of the carbonate, and metal- and sulfate-contaminated waters rise to the surface through compromised abandoned gas well casings. Strontium isotope mixing models suggest that neither upward migration of oil and gas brines from Devonian reservoirs associated with the wells nor dissolution of abundant nodular siderite present in the mine spoil through which recharge water percolates contribute significantly to the artesian gas well discharges. Natural Sr isotope composition can be a sensitive tool in the characterization of complex groundwater interactions and can be used to distinguish between inputs from deep and shallow contamination sources, as well as between groundwater and mineralogically similar but stratigraphically distinct rock units. This is of particular relevance to regions such as the Appalachian Basin, where a legacy of coal, oil and gas exploration is coupled with ongoing and future natural gas drilling into deep reservoirs.

  2. Comparative assessment of the environmental hazards of and exposure to perfluoroalkyl phosphonic and phosphinic acids (PFPAs and PFPiAs): Current knowledge, gaps, challenges and research needs.

    Wang, Zhanyun; Cousins, Ian T; Berger, Urs; Hungerbühler, Konrad; Scheringer, Martin

    2016-01-01

    Perfluoroalkyl phosphonic and phosphinic acids (PFPAs and PFPiAs) are sub-groups of per- and polyfluoroalkyl substances (PFASs) that have been commercialized since the 1970s, particularly as defoamers in pesticide formulations and wetting agents in consumer products. Recently, C4/C4 PFPiA and its derivatives have been presented as alternatives to long-chain PFASs in certain applications. In this study, we systematically assess the publicly available information on the hazardous properties, occurrence, and exposure routes of PFPAs and PFPiAs, and make comparisons to the corresponding properties of their better-known carboxylic and sulfonic acid analogs (i.e. PFCAs and PFSAs). This comparative assessment indicates that [i] PFPAs likely have high persistence and long-range transport potential; [ii] PFPiAs may transform to PFPAs (and possibly PFCAs) in the environment and biota; [iii] certain PFPAs and PFPiAs can only be slowly eliminated from rainbow trout and rats, similarly to long-chain PFCAs and PFSAs; [iv] PFPAs and PFPiAs have modes-of-action that are both similar to, and different from, those of PFCAs and PFSAs; and [v] the measured levels of PFPAs/PFPiAs in the global environment and biota appear to be low in comparison to PFCAs and PFSAs, suggesting, for the time being, low risks from PFPAs and PFPiAs alone. Although risks from individual PFPAs/PFPiAs are currently low, their ongoing production and use and high persistence will lead to increasing exposure and risks over time. Furthermore, simultaneous exposure to PFPAs, PFPiAs and other PFASs may result in additive effects necessitating cumulative risk assessments. To facilitate effective future research, we highlight possible strategies to overcome sampling and analytical challenges. PMID:26922149

  3. Analysis of four pentacyclic triterpenoid acids in several bioactive botanicals with gas and liquid chromatography and mass spectrometry detection.

    Moldoveanu, Serban C; Scott, Wayne A

    2016-01-01

    Several pentacyclic triterpenoid acids including betulinic, oleanolic, and ursolic acids were reported to have health beneficial properties such as antiviral and anti-inflammatory properties, as well as the capability to inhibit "in vitro" the development of various cancer cell types. For this reason betulinic, oleanolic, and ursolic acids are used as neutraceuticals. For the analysis of the pentacyclic triterpenoid acids in complex plant materials, an improved scheme was developed, involving a qualitative screening using silylation and gas chromatography with mass spectrometry analysis, followed by quantitation using a novel liquid chromatography with tandem mass spectrometry procedure. The use of the two methods provides more reliable information regarding the plant materials with unknown composition. Besides betulinic, oleanolic, and ursolic acids that were analyzed, by this procedure a fourth pentacyclic triterpenoid acid was identified and quantitated that was not previously reported to be present in plants. This acid has been identified as 3β-3-hydroxy-lupa-18,20(29)-dien-28-oic acid. The newly identified acid has a structure as a derivative of lupane, although lupane with a double bond in the 18-position was not previously reported as present in plants. The new liquid chromatography with tandem mass spectrometry procedure developed for this study offers a very low limit of quantitation, excellent precision, and robustness. Rosemary was found to contain the largest levels of pentacyclic triterpenoid acids among all the analyzed botanicals. PMID:26549610

  4. Hazardous wastes

    The dangers and problems of hazardous wastes are described in this pictorial booklet that is part of the EPA solid waste management publication series. It is shown that how the nation's hazardous wastes are managed or mismanaged is a crucial environmental issue with vast implications for public health and for the integrity of the ecological systems on which man depends. The environmental folly of dumping or burning these wastes is emphasized, along with the economic imprudence of continuing to throw away valuable resources as wastes. The public as well as industry must pay the costs of safe hazardous waste management

  5. Direct analysis of intact glycidyl fatty acid esters in edible oils using gas chromatography-mass spectrometry

    H. van Steenbergen; K. Hrnčiřík; A. Ermacora; S. de Koning; H.-G. Janssen

    2013-01-01

    Glycidyl esters (GE), fatty acid esters of glycidol, are process contaminants formed during edible oil processing. A novel direct method for the determination of intact GE in oils and fats based on gas chromatography-mass spectrometry (GC-MS) is presented. The method consists of a simple extraction

  6. Determination of urinary 18 beta-glycyrrhetinic acid by gas chromatography and its clinical application in man

    Guillaume, CPF; van der Molen, JC; Kerstens, MN; Dullaart, RPF; Wolthers, BG

    1999-01-01

    A sensitive and quantitative gas chromatographic assay for the determination of 18 beta-glycyrrhetinic acid (18 beta-GA), the main metabolite of glycyrrhizin after oral licorice consumption in human urine, has been developed and validated. For the extraction of 18 beta-GA from urine two Sep-Pak C-18

  7. PREPARATION OF ASYMMETRIC POLYETHERKETONE FLAT AND HOLLOW FIBER MEMBRANES FOR GAS SEPARATION USING ACETIC ACID BASED COAGULANTS

    Ji-ping Yang; Philip J. Brown

    2008-01-01

    Membranes for gas separation have developed significantly in the last twenty years, however, there is still a need for high temperature and chemically resistant membranes that exhibit good selectivity and gas permeability. Our study examines the fundamental properties of polyetherketone (PEK, a thermally stable and chemically resistant polymer)membranes prepared using concentrated sulphuric acid (98% H2SO4) as the solvent. Non-solvents used in the work included acetic acid, ethanol, methanol, glycerol, and water. The concentration of the polymer solutions was chosen to be 20%. The membrane structures were examined using SEM, and the gas separation properties were measured using a lab-scale test rig.The results show that formation and control of membrane structures are complicated, and many preparation parameters affect membrane morphology and performance. Using appropriate conditions skinned sponge-like structured hollow fiber membranes could be made from PEK by using acetic acid as the internal coagulant. PEK hollow fibers spun from 20%PEK/H2SO4 solutions with 50% aqueous acetic acid as internal coagulant had selectivity for hydrogen/methane of around 40, implying a solution diffusion separation mechanism for gas separation without the need for fiber coating or after post-treatments.

  8. Large carbon and nitrogen pools in subsoil of acid sulphate soils, a potential source for greenhouse gas emissions?

    Virtanen, S.; Šimek, Miloslav; Krištůfek, Václav; Simojoki, A.; Yli-Halla, M.

    2011-01-01

    Roč. 7, č. 3 (2011), s. 227. ISSN 1653-2015. [NJF Congress: Food , Feed, Fuel and Fun /24./, Nordic Feed Science Conference /2./. 14.06.2011-16.06.2011, Uppsala] Institutional research plan: CEZ:AV0Z60660521 Keywords : large carbon and nitrogen pools * acid sulphate soils * greenhouse gas emissions Subject RIV: EH - Ecology, Behaviour

  9. An optimized method for fatty acid analysis, including quantification of trans fatty acids, in human adipose tissue by gas-liquid chromatography

    Bysted, Anette; Cold, S; Hølmer, Gunhild Kofoed

    1999-01-01

    Considering the need for a quick direct method for measurement of the fatty acid composition including trans isomers ofhuman adipose tissue we have developed a procedure using gas-liquid chromatography (GLC) alone, which is thussuitable for validation of fatty acid status in epidemiological studies...... for 25 min, and finally raised at 25 degrees C/min to 225 degrees C. The trans and cis isomers of18:1 were well separated from each other, as shown by silver-ion thin-layer chromatography. Verification by standardsshowed that the trans 18:1 isomers with a double bond in position 12 or lower were...

  10. Separation of cis/trans fatty acid isomers on gas chromatography compared to the Ag-TLC method

    The present study investigates the separation of the cis/ trans isomers of fatty acids on the 75 m SP2560 column under different gas chromatographic (GC) conditions including an isothermal program and a time-temperature program. The time-temperature program showed improved separation of cis/trans isomers of C14:1, C16:1, C18:1, C18:2 and C18:3 fatty acids along with short chain fatty acids compared to the isothermal program. The separation of trans/trans isomers of C18:1 fatty acids including elaidic acid (C18:1 .9t) and vaccenic acid (C18:1 Δ11t) was difficult with the time-temperature program. The thin layer chromatography impregnated with silver nitrate (Ag- TLC) method was performed to separate cis/trans fractions and GC analysis was carried out with the trans fraction. But GC analysis showed a co-elution of trans isomers of C18:1 fatty acid. Thus the study shows that a time-temperature programmed GC method with the highly polar cyanopropyl column is sufficient to resolve trans fatty acids along with short chain fatty acids when a large number of samples has to be analyzed. (Author) 33 refs.

  11. Separation of cis/trans fatty acid isomers on gas chromatography compared to the Ag-TLC method

    Ravi Kiran, C.; Reshma, M. V.; Sundaresan, A.

    2013-05-01

    The present study investigates the separation of the cis/ trans isomers of fatty acids on the 75 m SP2560 column under different gas chromatographic (GC) conditions including an isothermal program and a time-temperature program. The time-temperature program showed improved separation of cis/trans isomers of C{sub 1}4:1, C{sub 1}6:1, C{sub 1}8:1, C{sub 1}8:2 and C{sub 1}8:3 fatty acids along with short chain fatty acids compared to the isothermal program. The separation of trans/trans isomers of C{sub 1}8:1 fatty acids including elaidic acid (C{sub 1}8:1 .9t) and vaccenic acid (C{sub 1}8:1 {Delta}11t) was difficult with the time-temperature program. The thin layer chromatography impregnated with silver nitrate (Ag- TLC) method was performed to separate cis/trans fractions and GC analysis was carried out with the trans fraction. But GC analysis showed a co-elution of trans isomers of C{sub 1}8:1 fatty acid. Thus the study shows that a time-temperature programmed GC method with the highly polar cyanopropyl column is sufficient to resolve trans fatty acids along with short chain fatty acids when a large number of samples has to be analyzed. (Author) 33 refs.

  12. Investigating the Weak to Evaluate the Strong: An Experimental Determination of the Electron Binding Energy of Carborane Anions and the Gas phase Acidity of Carborane Acids

    Meyer, Matthew M; Wang, Xue B; Reed, Christopher A; Wang, Lai S; Kass, Steven R

    2009-12-23

    Five CHB11X6Y5- carborane anions from the series X = Br, Cl, I and Y = H, Cl, CH3 were generated by electrospray ionization, and their reactivity with a series of Brønsted acids and electron transfer reagents were examined in the gas phase. The undecachlorocarborane acid, H(CHB11Cl11), was found to be far more acidic than the former record holder, (1-C4F9SO2)2NH (i.e., ΔH°acid = 241 ± 29 vs 291.1 ± 2.2 kcal mol-1) and bridges the gas-phase acidity and basicity scales for the first time. Its conjugate base, CHB11Cl11-, was found by photoelectron spectroscopy to have a remarkably large electron binding energy (6.35 ± 0.02 eV) but the value for the (1-C4F9SO2)2N- anion is even larger (6.5 ± 0.1 eV). Consequently, it is the weak H-(CHB11Cl11) BDE (70.0 kcal mol-1, G3(MP2)) compared to the strong BDE of (1-C4F9SO2)2N-H (127.4 ± 3.2 kcal mol-1) that accounts for the greater acidity of carborane acids.

  13. Hydrocarbon fuels from gas phase decarboxylation of hydrolyzed free fatty acid

    Wang, Weicheng

    2012-01-01

    Gas phase decarboxylation of hydrolyzed free fatty acid (FFA) from canola oil has beeninvestigated in two fix-bed reactors by changing reaction parameters such as temperatures,FFA feed rates, and H 2-to-FFA molar ratios. FFA, which contains mostly C 18 aswell as a few C 16, C 20, C 22, and C 24 FFA, was fed into the boiling zone, evaporated, carriedby hydrogen flow at the rate of 0.5-20 ml/min, and reacted with the 5% Pd/C catalystin the reactor. Reactions were conducted atmospherically at 380-450 °C and the products,qualified and quantified through gas chromatography-flame ionization detector(GC-FID), showed mostly n-heptadecane and a few portion of n-C 15, n-C 19, n-C 21, n-C 23 as well as some cracking species. Results showed that FFA conversion increased withincreasing reaction temperatures but decreased with increasing FFA feed rates and H 2-to-FFA molar ratios. The reaction rates were found to decrease with higher temperatureand increase with higher H 2 flow rates. Highly selective heptadecane was achieved byapplying higher temperatures and higher H 2-to-FFA molar ratios. From the results, ascatalyst loading and FFA feed rate were fixed, an optimal reaction temperature of 415 °C as well as H 2-to-FFA molar ratio of 4.16 were presented. These results provided goodbasis for studying the kinetics of decarboxylation process. © 2012 American Society of Mechanical Engineers.

  14. Dry flue gas desulfurization byproducts as amendments for reclamation of acid mine spoil

    Development of beneficial reuses of highly alkaline, dry flue gas desulfurization (FGD) byproducts can impact the economics of adopting these FGD technologies for retrofit on existing powerplants. Greenhouse studies were conducted to evaluate the use of two dry FGD byproducts for reclamation of acid mine spoil (pH, 3.1 to 5.8). Treatment rates of FGD ranges from 0% to 32% by dry weight and most treatments also included 6% by dry weight of sewage sludge. Fescue (Festuca arundinacea Schreb.) was harvested monthly for a total of six harvests. Plant tissue composition and root growth were determined after the sixth harvest. Leachate analyses and pH determination of mixes were done at the beginning and end of the experiments. Both FGD byproducts were effective in raising the spoil pH and in improving fescue growth. At the highest FGD application rate, fescue growth decreased from the optimum due to high pH and reduced rooting volume caused by cementation reactions between the FGD and spoil. Trace elements, with the exception of B, were decreased in the fescue tissue when FGD was applied. Leachate pH, electrical conductivity, dissolved organic carbon, Ca, Mg, and S tended to increase with increased FGD application rate; Al, Fe, Mn, and Zn decreased. pH was the most important variable controlling the concentrations of these elements in the leachate. Concentrations of elements of environmental concern were near or below drinking water standard levels. These results indicate that FGD applied at rates equivalent to spoil neutralization needs can aid in the revegetation of acid spoil revegetation with little potential for introduction of toxic elements into the leachate water or into the food chain

  15. Identify alkylation hazards

    This paper reports that extensive experience shows that alkylation plants regardless of acid catalyst choice, can be operated safely, and with minimum process risk to employees or neighbors. Both types of plants require a comprehensive and fully supported hazard management program that accounts for differing physical properties of the acids involved. Control and mitigation cost to refiners will vary considerably from plant to plant and location to location. In the author's experience, the order of magnitude costs will be about $1 to $2 million for a sulfuric acid (SA) alkylation plant, and about $10 to $15 million for a hydrofluoric acid (HF) plant. These costs include water supply systems and impoundment facilities for contaminated runoff water. The alkylation process, which chemically reacts isobutane and light olefins in the presence of a strong acid catalyst into a premium gasoline component is described

  16. Gas-phase hydrolysis of triplet SO2: A possible direct route to atmospheric acid formation.

    Donaldson, D James; Kroll, Jay A; Vaida, Veronica

    2016-01-01

    Sulfur chemistry is of great interest to the atmospheric chemistry of several planets. In the presence of water, oxidized sulfur can lead to new particle formation, influencing climate in significant ways. Observations of sulfur compounds in planetary atmospheres when compared with model results suggest that there are missing chemical mechanisms. Here we propose a novel mechanism for the formation of sulfurous acid, which may act as a seed for new particle formation. In this proposed mechanism, the lowest triplet state of SO2 ((3)B1), which may be accessed by near-UV solar excitation of SO2 to its excited (1)B1 state followed by rapid intersystem crossing, reacts directly with water to form H2SO3 in the gas phase. For ground state SO2, this reaction is endothermic and has a very high activation barrier; our quantum chemical calculations point to a facile reaction being possible in the triplet state of SO2. This hygroscopic H2SO3 molecule may act as a condensation nucleus for water, giving rise to facile new particle formation (NPF). PMID:27417675

  17. Numerical study on laminar circular jet of carbonic acid gas discharging into stagnant air

    The flow behavior of the circular jet of two component gases is the most fundamental study in that of multi-component gases. The objective of present study is to investigate numerically the fluid flow and diffusion behavior of laminar circular jet of carbonic acid gas (CO2) discharging into stagnant air along gravity force. The flow and CO2 mass fraction distribution analysis was carried out by modified TEAM (Turbulent Elliptic Algorithm Manchester) code which solved elliptic equations using staggered grid system. As the result, the followings were obtained in the range of Froude number Fr = 0.007 - 0.7: (1) Axial velocity increased along down stream because the jet accelerated by gravity force. (2) It was necessary to obtain accurate radial velocity to evaluate CO2 mass fraction distribution. (3) In the case of low Froude number, half radii of axial velocity and CO2 mass fraction distribution increased along the flow direction as well as the conventional buoyant jet. In the case of relatively high Froude number, however, half radius of axial velocity distribution was constant and half radius of CO2 mass fraction decreased along the flow direction. (author)

  18. Advanced Acid Gas Separation Technology for the Utilization of Low Rank Coals

    Kloosterman, Jeff

    2012-12-31

    Air Products has developed a potentially ground-breaking technology – Sour Pressure Swing Adsorption (PSA) – to replace the solvent-based acid gas removal (AGR) systems currently employed to separate sulfur containing species, along with CO{sub 2} and other impurities, from gasifier syngas streams. The Sour PSA technology is based on adsorption processes that utilize pressure swing or temperature swing regeneration methods. Sour PSA technology has already been shown with higher rank coals to provide a significant reduction in the cost of CO{sub 2} capture for power generation, which should translate to a reduction in cost of electricity (COE), compared to baseline CO{sub 2} capture plant design. The objective of this project is to test the performance and capability of the adsorbents in handling tar and other impurities using a gaseous mixture generated from the gasification of lower rank, lignite coal. The results of this testing are used to generate a high-level pilot process design, and to prepare a techno-economic assessment evaluating the applicability of the technology to plants utilizing these coals.

  19. Penetration of methyl isocyanate through organic vapor and acid gas respirator cartridges.

    Moyer, E S; Berardinelli, S P

    1987-04-01

    Methyl isocyanate (MIC) is a volatile, toxic chemical [Threshold Limit Value (TLV) = 0.02 ppm] used to manufacture carbamate pesticides. The principal manufacturer of MIC is Union Carbide, and the site of production is Institute, West Virginia. In light of the December 1984 Bhopal, India disaster and possible safety problems at the Institute facility, NIOSH conducted this research as a basis upon which to recommend protective equipment that might be used in an emergency situation where extremely high MIC concentrations might be encountered. Both protective clothing and respirators were evaluated. In particular, NIOSH studied air-purifying respirators in order to assess their effectiveness against MIC vapor penetration. NIOSH does not recommend any air purifying respirator for MIC because of its high toxicity and lack of warning properties and because no effective end of service life indicator currently is available for MIC. This report addresses only MIC penetration through air-purifying cartridges at challenge concentrations designed to simulate emergency escape conditions. Another report addresses the protective clothing issue. The results presented are for two different manufacturers' organic vapor (OV) and acid gas cartridges. Penetration tests were conducted at three or four MIC challenge concentrations and at three different humidity conditions. In general, breakthrough times (1% of challenge concentration) were very short (less than 20 min). Also, high relative humidity was found to decrease the breakthrough time of MIC. PMID:3591646

  20. Growth, Gas Exchange, Abscisic Acid, and Calmodulin Response to Salt Stress in Three Poplars

    2006-01-01

    In the present study, we investigated the effects of increasing salinity on growth, gas exchange, abscisic acid(ABA), calmodulin (CAM), and the relevance to salt tolerance in seedlings of Populus euphratica Oliv. and cuttings of P. "pupularis 35-44" (P. popularis) and P. x euramericana cv. 1-214 (P. cv. Italica). The relative growth rates of shoot height (RGRH) for P. cv. Italica and P. popularis were severely reduced by increasing salt stress,whereas the growth reduction was relatively less in P. euphratica. Similarly, P. euphratica maintained higher net photosynthetic rates (Pn) and unit transpiration rates (TRN) than P. cv. Italica and P. popularis under conditions of higher salinity. Salinity caused a significant increase in leaf ABA and CaM in the three genotypes after the onset of stress, but NaCl-induced ABA and CaM accumulation was more pronounced in P. euphratica,suggesting that P. euphratica plants are more sensitive in sensing soil salinity than the other two poplars.Furthermore, P. euphratica maintained relatively higher ABA and CaM concentrations under conditions of high salinity. The higher capacity to synthesize stress signals, namely ABA and CaM, in P. euphratica and the contribution of this to the salt resistance of P. euphratica are discussed.

  1. Optimizing Techology to Reduce Mercury and Acid Gas Emissions from Electric Power Plants

    Jeffrey C. Quick; David E. Tabet; Sharon Wakefield; Roger L. Bon

    2004-01-31

    More than 56,000 coal quality data records from five public data sets have been selected for use in this project. These data will be used to create maps showing where coals with low mercury and acid-gas emissions might be found for power plants classified by air-pollution controls. Average coal quality values, calculated for 51,156 commercial coals by U.S. county-of-origin, are listed in the appendix. Coal moisture values are calculated for commercially shipped coal from 163 U.S. counties, where the raw assay data (including mercury and chlorine values) are reported on a dry basis. The calculated moisture values are verified by comparison with observed moisture values in commercial coal. Moisture in commercial U.S. coal shows provincial variation. For example, high volatile C bituminous rank coal from the Interior province has 3% to 4% more moisture than equivalent Rocky Mountain province coal. Mott-Spooner difference values are calculated for 4,957 data records for coals collected from coal mines and exploration drill holes. About 90% of the records have Mott-Spooner difference values within {+-}250 Btu/lb.

  2. Determination of naphthenic acid profile in Ghana's Jubilee Oil using gas chromatography-mass spectrometry

    Crude oil is the life-blood of the global economy. Its importance stems from the fact that it is a base product for a wide variety of goods [Drugs, Plastics, Liquefied Petroleum Gas (LPG)]. The oil discovery (over 3 billion barrel reserves in hydrocarbon and gas), about 60 km offshore between the Deepwater Tano and Cape Three Points Block in South western Ghana is a valuable natural asset and it has the potential of boosting the Ghanaian economy. During petroleum processing, various waste products are generated. One of such products is Naphthenic acids (NA). Naphthenic acids are organic acids naturally occurring in crude oil and a constituent of waste associated with oil refinery. Naphthenic acids serve as biomarkers for identification of the source of crude oil. The presence of Naphthenic acid in the aquatic environment causes toxic effects due to their weak biodegradable nature; the toxicity of Naphthenic acids depends on the class of Naphthenic acids present in the crude oil. The study assessed the profile of Naphthenic acids in Ghana’s Jubilee crude oil using Low Resolution Electron Impact – Gas Chromatography Mass Spectrometry (LREI-GCMS) after isolation of Naphthenic acids in the Jubilee oil by a modified Kupchan’s Partitioning Process. The Mass Spectrometric (MS) Work Station Software was used for the identification of the Naphthenic acids present in the Jubilee crude oil. The quality of the Jubilee oil was also evaluated through the use of some key physico-chemical parameters [Total Acid Number (TAN), Sulphur Content, Viscosity, Pour Point, Flashpoint, Water Content and Densities] based on the American Standards for Testing and Materials (ASTM, 2007). The Total Acid Number was determined by Colorimetric Titration (ASTM D974); Sulphur Content by X-ray Fluorescent Spectrometry (ASTM D4294); Pour Point by the use of the SETA cloud and Pour Point Refrigerator Technique (ASTM D97); Viscosity by Gravity Timed Method (ASTM D445); Density by the Hydrometer

  3. The effect of H2SO4 – amine clustering on chemical ionization mass spectrometry (CIMS) measurements of gas-phase sulfuric acid

    Kurtén, T.; T. Petäjä; Smith,J; Ortega, I.K.; Sipilä, M.; Junninen, H.; M. Ehn; Vehkamäki, H.; Mauldin, L.; Worsnop, D.R.; M. Kulmala

    2011-01-01

    The state-of-the art method for measuring atmospheric gas-phase sulfuric acid is chemical ionization mass spectrometry (CIMS) based on nitrate reagent ions. We have assessed the possible effect of the sulfuric acid molecules clustering with base molecules on CIMS measurements using computational chemistry. From the computational data, three conclusions can be drawn. First, a significant fraction of the gas-phase sulfuric acid molecules are very likely clustered with amines i...

  4. Determination of the optimum conditions for boric acid extraction with carbon dioxide gas in aqueous media from colemanite containing arsenic

    Ata, O.N.; Colak, S.; Copur, M.; Celik, C.

    2000-02-01

    The Taguchi method was used to determine optimum conditions for the boric acid extraction from colemanite ore containing As in aqueous media saturated by CO{sub 2} gas. After the parameters were determined to be efficient on the extraction efficiency, the experimental series with two steps were carried out. The chosen experimental parameters for the first series of experiments and their ranges were as follows: (1) reaction temperature, 25--70 C; (2) solid-to-liquid ratio (by weight), 0.091 to 0.333; (3) gas flow rate (in mL/min), 66.70--711; (4) mean particle size, {minus}100 to {minus}10 mesh; (5) stirring speed, 200--600 rpm; (6) reaction time, 10--90 min. The optimum conditions were found to be as follows: reaction temperature, 70 C; solid-to-liquid ratio, 0.091; gas flow rate, 711 (in mL/min); particle size, {minus}100 mesh; stirring speed, 500 rpm; reaction time, 90 min. Under these optimum conditions, the boric acid extraction efficiency from the colemanite containing As was approximately 54%. Chosen experimental parameters for the second series of experiments and their ranges were as follows: (1) reaction temperature, 60--80 C; (2) solid-to-liquid ratio (by weight), 0.1000 to 0.167; (3) gas pressure (in atm), 1.5; 2.7; (4) reaction time, 45--120 min. The optimum conditions were found to be as follows: reaction temperature, 70 C; solid-to-liquid ratio, 0.1; gas pressure, 2.7 atm; reaction time, 120 min. Under these optimum conditions the boric acid extraction efficiency from the colemanite ore was approximately 75%. Under these optimum conditions, the boric acid extraction efficiency from calcined colemanite ore was approximately 99.55%.

  5. Hazardous Chemicals

    2007-04-10

    Chemicals are a part of our daily lives, providing many products and modern conveniences. With more than three decades of experience, The Centers for Disease Control and Prevention (CDC) has been in the forefront of efforts to protect and assess people's exposure to environmental and hazardous chemicals. This report provides information about hazardous chemicals and useful tips on how to protect you and your family from harmful exposure.  Created: 4/10/2007 by CDC National Center for Environmental Health.   Date Released: 4/13/2007.

  6. Gas chromatography of alkylphosphonic and dialkyl phosphinic acids; Cromatografia en fase gaseosa de acidos alquifosfonicos y dialquilfosinicos

    Gasco Sanchez, L.; Barrera Peniero, R.; Ramirez Caceres, A.; Marin Munoz, M.

    1978-07-01

    After carrying out an optimization study on the separation conditions for the TMSr- derivatives, of the hexyl-, cyclohexyl-, heptyl-, and octyl-phosphonic acids; dihexyl dicyclohexyl-, heptyl-, and octyl-phosphinic acids, and dioctyl phosphine oxide, their retention indices (I) at two temperatures and on the OV-1 and OV-17 stationary phase were determined. Correlations between I and molecular structure were established. Calibration factors of these compounds in the flame ionization detector were studied, and the results analyzed taking into account the variables affecting the quantitative results, These results were unbiased but they had a lower precision than that usually achievable in gas chromatography. (Author) 24 refs.

  7. Comparison of gas chromatographic and gravimetric methods for quantization of total fat and fatty acids in foodstuffs

    Sabria Aued-Pimentel

    2010-01-01

    Full Text Available Different methods to determine total fat (TF and fatty acids (FA, including trans fatty acids (TFA, in diverse foodstuffs were evaluated, incorporating gravimetric methods and gas chromatography with flame ionization detector (GC/FID, in accordance with a modified AOAC 996.06 method. Concentrations of TF and FA obtained through these different procedures diverged (p< 0.05 and TFA concentrations varied beyond 20 % of the reference values. The modified AOAC 996.06 method satisfied both accuracy and precision, was fast and employed small amounts of low toxicity solvents. Therefore, the results showed that this methodology is viable to be adopted in Brazil for nutritional labeling purposes.

  8. Assay of methylmalonic acid in the serum of patients with cobalamin deficiency using capillary gas chromatography-mass spectrometry.

    Stabler, S.P.; Marcell, P D; Podell, E R; Allen, R. H.; Lindenbaum, J

    1986-01-01

    To determine the incidence of elevated levels of serum methylmalonic acid in patients with cobalamin deficiency, we utilized a new capillary gas chromatographic-mass spectrometric technique to measure methylmalonic acid in the serum of 73 patients with clinically confirmed cobalamin deficiency. Values ranged from 55 to 22,300 ng/ml, and 69 of the 73 patients had values above the normal range of 19-76 ng/ml as determined for 50 normal blood donors. In the cobalamin-deficient patients, serum me...

  9. Identification of rapeseed oil fatty acid esters in transesterification reactions by gas chromatography - mass spectrometry method

    Rapeseed oil transesterification with different alcohols - methyl, ethyl, n-propyl and isopropyl alcohol - has been carried out. Yields of fatty acid alkyl esters obtained from rapeseed oil were determined using the internal standard method. Results of interpretation of the obtained ester mass spectra are reported. The specimen of Latvian rape oil contains: 57.6% of oleic acid, 18.2% of linoleic acid, 8.2% linolenic acid, 3.3% palmitic acid, 2% of stearic acid and less than 1% of arachidic acid. Values of Kovats retention indices of the rapeseed oil fatty acid esters on the capillary columns DB-5 MS and DB-17 MS have been compared. More selective separation of fatty acid alkyl esters has been achieved on the stationary phase with higher content of phenyl groups (DB-17 MS). (authors)

  10. Investigations of acidity and nucleophilicity of diphenyldithiophosphinate ligands using theory and gas-phase dissociation reactions

    Christopher M. Leavitt; Garold L. Gresham; Michael T. Benson; Jean-Jaques Gaumet; Dean Peterman; John Klaehn; Megan Moser; Frederic Aubriet; Michael J. Van Stipdonk; Gary S. Groenewold

    2008-04-01

    Diphenyldithiophosphinate (DTP) ligands modified with electron-withdrawing trifluoromethyl (TFM) substitutents are of high interest because they have demonstrated potential for exceptional separation of Am3+ from lanthanide3+ cations. Specifically, the bis(ortho-TFM) (L1-) and (ortho-TFM)(meta-TFM) (L2-) derivatives have shown excellent separation selectivity, while the bis(meta-TFM) (L3)- and unmodified DTP (Lu-) did not. Factors responsible for selective coordination have been investigated using density functional theory (DFT) calculations in concert with competitive dissociation reactions in the gas phase. To evaluate the role of (DTP+H) acidity, density functional calculations were used to predict pKa values, which followed the trend of L3 < L2 < L1 < Lu. The order of the TFM-modified (DTP+H) acids was opposite of what would be expected based on the e--withdrawing effects of the TFM group, suggesting that secondary factors are influencing the pKa and nucleophilicity. The relative nucleophilicities of the DTP anions were evaluated by forming metal-mixed ligand complexes in a trapped ion mass spectrometer, and then fragmenting them using competitive collision induced dissociation. Relative to Na+, the unmodified Lu- anion was the strongest nucleophile. Comparing the TFM derivatives, the bis(ortho-TFM) derivative L1- was found to be the strongest nucleophile, while the bis(meta-TFM) L3- was the weakest, a trend consistent with the pKa calculations. DFT modeling of the Na+ complexes suggested that the elevated cation affinity of the L1- and L2- anions was due to donation of electron density from fluorine atoms to the metal center, which was occurring in rotational conformers where the TFM moiety was proximate to the Na+-dithiophosphinate group. Competitive dissociation experiments were performed with the dithiophosphinate anions complexed with europium nitrate species; ionic dissociation of these complexes always produced the TFM-modified dithiophosphinate anions

  11. Electrogeneration of hydrogen peroxide in acidic medium using gas diffusion electrodes modified with cobalt (II) phthalocyanine

    Hydrogen peroxide (H2O2) is a commonly used oxidant with a wide variety of applications in, for example, organic synthesis and wastewater treatment. This paper describes the development of catalysts for the electrogeneration of H2O2 in acidic medium using gas diffusion electrodes (GDE). Initial experiments were performed using rotating ring-disk electrodes modified with microporous layers of Printex 6L carbon containing various amounts of cobalt (II) phthalocyanine (CoPc) in order to evaluate catalytic activities. The results showed that the current efficiency for the formation of H2O2 increased from 69.7% for Printex 6L carbon without catalyst to 81.5% when using Printex 6L carbon with CoPc, and this was accompanied by a decrease in the number of electrons involved in the oxygen reduction reaction from 2.6 to 2.3. Based on these findings, modified GDEs were constructed containing 3.0, 5.0 and 10.0% of CoPc on Printex 6L carbon. The concentration of H2O2 that formed after 90 min electrolysis with the GDE modified with Printex 6L carbon alone was 176 mg L−1, while the GDE with 5.0% CoPc on carbon produced 331 mg L−1 of H2O2, i.e. an increase in yield of 89.1% relative to Printex 6L carbon. Additionally, using GDE s modified with CoPc on carbon, the potential at which H2O2 formation attained its maximum value shifted to less negative values in comparison with electrodes without catalyst. It is concluded that CoPc is an appropriate catalyst for efficient electrogeneration of H2O2

  12. Development of a Gas Chromatography-Mass Spectrometry Method for the Quantification of Glucaric Acid Derivatives in Beverage Substrates

    Ana Paula Craig; Fields, Christine C.; Simpson, John V.

    2014-01-01

    A gas chromatography-mass spectrometry (GC-MS) method using the standard addition methodology was developed for the determination of glucuronolactone (GL) and glucuronic acid (DGuA) in four beverages categorized as detoxification, recovery, or energy drinks. The method features a precolumn derivatization step with a combination of BSTFA (N,O-bis(trimethylsilyl)trifluoroacetamide) and TMCS (trimethylchlorosilane) to silylate the analytes. The sample pretreatment required no extraction, filtrat...

  13. Characterization of Fatty Acid Profile of Argan Oil and Other Edible Vegetable Oils by Gas Chromatography and Discriminant Analysis

    Ascensión Rueda; Isabel Seiquer; Manuel Olalla; Rafael Giménez; Luis Lara; Carmen Cabrera-Vique

    2014-01-01

    Virgin argan oil is an emergent oil that is being introduced into specialized international markets as a healthy and luxury food. In order to compare the fatty acid composition of argan oil with that of the eleven other vegetable edible oils, a combination of gas chromatography as analytical technique and multivariate discriminant analysis was applied. This analysis takes into account the conjoint effect of all the variables analyzed in the discrimination between oils and also shows the contr...

  14. Interactions of Gas-Phase Nitric/Nitrous Acids and Primary Organic Aerosol in the Atmosphere of Houston, TX

    Ziemba, L. D.; Griffin, R. J.; Dibb, J. E.; Anderson, C. H.; Whitlow, S. I.; Lefer, B. L.; Flynn, J.; Rappenglück, B.

    2007-12-01

    Concentrations of aerosol and gas-phase pollutants were measured on the roof of an 18-story building during the Texas Air Quality Study II Radical and Aerosol Measurement Project (TRAMP) from August 15 through September 28, 2006. Aerosol measurements included size-resolved, non-refractory mass concentrations of ammonium, nitrate, sulfate, chloride, and organic aerosol in submicron particles using an Aerodyne quadrupole aerosol mass spectrometer (Q-AMS). Particulate water-soluble organic carbon (PWSOC) was quantified using a mist chamber/total organic carbon analysis system. Concentration data for gas-phase pollutants included those for nitric acid (HNO3), nitrous acid (HONO), and hydrochloric acid (HCl) collected using a mist chamber/ion chromatographic technique, oxides of nitrogen (NOx) collected using a chemiluminescent method, and carbon monoxide (CO) collected using an infrared gas correlation wheel instrument. Coincident increases in nitrate and organic aerosol mass concentrations were observed on many occasions throughout the measurement campaign, most frequently during the morning rush hour. Based on the lack of organic aerosol processing (defined by the ratio of m/z = 44/57 in the Q-AMS spectra), strong correlation with NOx and CO, and a lack of significant increase in PWSOC concentration, the spikes in organic aerosol were likely associated with primary organic aerosol (POA). During these events, gas-phase HNO3 concentration decreases were observed simultaneously with increases in gas-phase HONO concentrations. These data likely indicate uptake of HNO3 and subsequent heterogeneous conversion to HONO involving POA. Preliminary calculations show that HNO3 partitioning could account for the majority of the observed HONO and aerosol nitrate concentrations during these events. Q-AMS chloride and HCl data also indicate uptake of chloride by particles during these events. This phenomenon was also observed during the night, but these nocturnal events were less

  15. In situ derivatization and hollow fiber membrane microextraction for gas chromatographic determination of haloacetic acids in water

    An alternative method for gas chromatographic determination of haloacetic acids (HAAs) in water using direct derivatization followed by hollow fiber membrane liquid-phase microextraction (HF-LPME) has been developed. The method has improved the sample preparation step according to the conventional US EPA Method 552.2 by combining the derivatization and the extraction into one step prior to determination by gas chromatography electron captured detector (GC-ECD). The HAAs were derivatized with acidic methanol into their methyl esters and simultaneously extracted with supported liquid hollow fiber membrane in headspace mode. The derivatization was attempted directly in water sample without sample evaporation. The HF-LPME was performed using 1-octanol as the extracting solvent at 55 deg. C for 60 min with 20% Na2SO4. The linear calibration curves were observed for the concentrations ranging from 1 to 300 μg L-1 with the correlation coefficients (R2) being greater than 0.99. The method detection limits of most analytes were below 1 μg L-1 except DCAA and MCAA that were 2 and 18 μg L-1, respectively. The recoveries from spiked concentration ranged from 97 to 109% with %R.S.D. less than 12%. The method was applied for determination of HAAs in drinking water and tap water samples. The method offers an easy one step high sample throughput sample preparation for gas chromatographic determination of haloacetic acids as well as other contaminants in water

  16. Per-fluorinated sulfonic acid/PTFE copolymer studied by positron annihilation lifetime and gas permeation techniques

    Mohamed, Hamdy F. M.; Abdel-Hady, E. E.; Ohira, A.

    2015-06-01

    The mechanism of gas permeation in per-fluorinated sulfonic acid/PTFE copolymer Fumapem® membranes for polymer electrolyte fuel cells has been investigated from the viewpoint of free volume. Three different samples, Fumapem® F-950, F-1050 and F-14100 membranes with ion exchange capacity (IEC) = 1.05, 0.95 and 0.71 meq/g, respectively were used after drying. Free volume was quantified using the positron annihilation lifetime (PAL) technique and gas permeabilities were measured for O2 and H2 as function of temperature. Good linear correlation between the logarithm of the permeabilities at different temperatures and reciprocal free volume indicate that gas permeation in dry Fumapem® is governed by the free volume. Nevertheless permeabilities are much smaller than the corresponding flexible chain polymer with a similar free volume size due to stiff chains of the perfluoroethylene backbone.

  17. Application of gas-liquid chromatographic analysis of cellular fatty acids for species identification and typing of coagulase-negative staphylococci.

    Kotilainen, P; Huovinen, P; Eerola, E

    1991-01-01

    Gas-liquid chromatography (GLC) of bacterial cellular fatty acids was used to analyze 264 isolates of coagulase-negative staphylococci, of which 178 were Staphylococcus epidermidis. The presence and amounts of individual fatty acids were determined to generate fatty acid profiles for each of the seven coagulase-negative species tested. The fatty acid profiles were then analyzed by computerized correlation and cluster analysis to calculate mean correlation values between isolates belonging to ...

  18. 46 CFR 153.556 - Special requirements for sulfuric acid and oleum.

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Special requirements for sulfuric acid and oleum. 153.556 Section 153.556 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Design and Equipment Special Requirements §...

  19. Validation of a method by gas chromatography for the determination of fatty acids that comprise the active ingredient D-004

    D-004 is a new active ingredient obtained from the Cuban royal palm (Roystonea regia) fruits. This substance is mainly composed by a mixture of saturated and unsaturated free fatty acids, from 8 to 18 carbon atoms, and has shown to be effective in experimental model of prostate hyperplasia. A capillary gas chromatographic method for the determination of the fatty acids in D-004 was developed and validated. The acids were analyzed as methyl ester derivatives, which were obtained by reaction with 10 % acetyl chloride in methanol and separated in a BPX-5 wide-bore column using tridecanoic acid as internal standard. The specificity study showed no interferences regarding the determination of this mixture, once the samples were submitted to stress conditions. Determination of the total fatty acid content was linear (r > 0.999; CVs of the response factors and of the slopes lower than 5 and 2 %, respectively) and without bias in the studied concentration range, from 50 to 150 % of the nominal mass. In the accuracy study, over the range 80 to 120 % of the nominal fatty acid concentration, high recoveries (100.4 to 100.8 %) were reached. Good results were obtained in the repeatability and intermediate precision studies (CV < 2%), proving that the method is precise. These results support that this method is properly validated, being appropriate for the quality control and stability studies of this active ingredient

  20. Evaluation of a sunscreen photoprotective effect by ascorbic acid assessment in human dermis using microdialysis and gas chromatography mass spectrometry.

    Lévêque, Nathalie; Mac-Mary, Sophie; Muret, Patrice; Makki, Safwat; Aubin, Francois; Kantelip, Jean-Pierre; Heusèle, Catherine; S, Schnebert; Humbert, Philippe

    2005-03-01

    Ultraviolet irradiation causes adverse effects like sunburn, photosensitivity reactions or immunologic suppression. The aim of this study was to evaluate the photo-protective outcome of a sunscreen cream (SPF8) by the determination of erythema indexes and the assessment of ascorbic acid and its metabolites in human dermis. These substances were used as markers of oxidative effect. Eight healthy female subjects were enrolled in this study. Two abdominal areas were exposed to solar simulated irradiation with three minimal erythema dose, one with SPF8 application and the other site without SPF8 application. Two other areas were used as control, one without SPF8 application and the other site after SPF8 application. Ascorbic acid and its metabolites (dehydroascorbic acid, threonic acid, oxalic acid and xylose) were collected from human dermis by microdialysis and assessed by gas chromatography mass spectrometry. Irradiated site without sunscreen application had significantly demonstrated lower dermis ascorbic acid concentrations and a higher erythema index than the three other sites (P creams against undesirable UV effects. PMID:15740589

  1. Isolation of individual fatty acids in sediments using preparative capillary gas chromatography (PCGC) for radiocarbon analysis at NIES-TERRA

    Compound-specific radiocarbon analysis (CSRA) of individual fatty acids (140-1190 μg C) in an estuarine sediment sample collected from Tokyo Bay was carried out using a recently developed preparative capillary gas chromatography (PCGC) system and accelerator mass spectrometry (AMS). The results showed that the estimated 14C ages of four components greatly varied from modern age (combined iso and anteiso C15:0, C16:0) to 17 000 years BP (C22:0), while a bulk-phase 14C age of organic matter is 5000 years BP. The 14C ages of the fatty acids derived from phytoplankton and bacteria are much younger than that of the bulk phase. On the other hand, the fatty acid originated from terrestrial higher plants (C22:0) shows an older 14C age of 17 000 years BP

  2. The microbial communities and potential greenhouse gas production in boreal acid sulphate, non-acid sulphate, and reedy sulphidic soils

    Šimek, Miloslav; Virtanen, S.; Simojoki, A.; Chroňáková, Alica; Elhottová, Dana; Krištůfek, Václav; Yli-Halla, M.

    2014-01-01

    Roč. 466, January (2014), s. 663-672. ISSN 0048-9697 R&D Projects: GA ČR GA526/09/1570; GA MŠk LC06066 Grant ostatní: GAJU(CZ) GAJU 138/2010/P Institutional support: RVO:60077344 Keywords : acid sulphate soil * carbon * CARD-FISH * microorganisms * nitrogen * PLFA Subject RIV: EE - Microbiology, Virology Impact factor: 4.099, year: 2014

  3. The chemical processing of gas-phase carbonyl compounds by sulfuric acid aerosols: 2,4-pentanedione

    Nozière, Barbara; Riemer, Daniel D.

    This work investigates the interactions between gas-phase carbonyl compounds and sulfuric acid aerosols. It focuses on understanding the chemical processes, giving a first estimate of their importance in the atmosphere, and suggesting directions for further investigations. The solubility and reactivity of a compound with a large enolization constant, 2,4-pentanedione, in water/sulfuric acid solutions 0-96 wt% have been investigated at room temperature using the bubble column/GC-FID technique. 2,4-pentanedione was found to undergo aldol condensation at acidities as low as 20 wt% H 2SO 4, that is, well in the tropospheric range of aerosol composition. In agreement with well-established organic chemical knowledge, this reaction resulted in changes of color of the solutions of potential importance for the optical properties of the aerosols. 2,4-pentanedione was also found to undergo retroaldol reaction, specific to dicarbonyl compounds, producing acetone and acetaldehyde. The Henry's law coefficient for 2,4-pentanedione was found to be a factor 5 larger than the one of acetone over the whole range of acidity, with a value in water of H (297 K)=(155±27) M atm -1. A chemical system is proposed to describe the transformations of carbonyl compounds in sulfuric acid aerosols. Aldol condensation is likely to be the most common reaction for these compounds, probably involving a large number of the ones present in the atmosphere and a wide range of aerosol compositions. The enolization constant contributes as a proportional factor to the rate constant for aldol condensation, and is shown in this work to contribute as an additive constant to the Henry's law coefficient. In addition to the many important aspects of these reactions illustrated in this work, the rate of aldol condensation was estimated to be potentially fast enough for the losses of some compounds in acidic aerosols to compete with their gas-phase chemistry in the atmosphere.

  4. Data for generation of all Tables and Figures for AIMS-ES publication in 2016 pertaining to dry sorbent injection of trona for acid gas control

    U.S. Environmental Protection Agency — emissions data and removal efficiencies for coal combustion utilizing PM control devices and dry sorbent injection of trona specifically for acid gas control This...

  5. Direct analysis of fatty acid profile from milk by thermochemolysis-gas chromatography-mass spectrometry.

    Gomes Reis, Mariza; dos Reis, Marlon Martins; Leath, Shane; Stelwagen, Kerst

    2011-01-14

    The fatty acid composition of milk is of considerable interest due to their nutritional and functional properties. Although rapid milk fat separation and transesterification procedures have been developed, the overall procedure remains time consuming, specially, for the analysis of a large number of samples. In this work, a fast and simple method for direct profiling of fatty acids from milk using thermochemolysis has been developed. This method has the capability of directly analyse fatty acids from one drop of milk without fat extraction or cleanup. Our approach for thermochemolysis is based on thermal desorption integrated with a cold trap inlet. The optimized method does not present isomerisation/degradation of polyunsaturated fatty acid and shows milk fatty acid profiles comparable to the conventional method based on fat extraction and alkaline transesterification. Overall, this method has demonstrated significant potential for high throughput analysis of fatty acids in milk. PMID:21144530

  6. Hazardous Air Pollutants

    ... Facebook Twitter Google+ Pinterest Contact Us Hazardous Air Pollutants Hazardous air pollutants are those known to cause ... protect against adverse environmental effects. About Hazardous Air Pollutants What are hazardous air pollutants? Health and Environmental ...

  7. Formation of gas-phase carbonyls from heterogeneous oxidation of polyunsaturated fatty acids at the air–water interface and of the sea surface microlayer

    Zhou, S; Gonzalez, L.; Leithead, A.; Finewax, Z.; Thalman, R.; Vlasenko, A.; S. Vagle; Miller, L.; S.-M. Li; Bureekul, S.; Furutani, H.; Uematsu, M.; R. Volkamer; Abbatt, J.

    2013-01-01

    Motivated by the potential for reactive heterogeneous chemistry occurring at the ocean surface, gas-phase products were observed when a reactive sea surface microlayer (SML) component, i.e. the polyunsaturated fatty acid (PUFA) linoleic acid (LA), was exposed to gas-phase ozone at the air–seawater interface. Similar oxidation experiments were conducted with SML samples collected from two different oceanic locations, in the eastern equatorial Pacific Ocean and from the west coast of Can...

  8. Research on the Interaction of Hydrogen-Bond Acidic Polymer Sensitive Sensor Materials with Chemical Warfare Agents Simulants by Inverse Gas Chromatography

    Liu Yang; Qiang Han; Shuya Cao; Feng Huang; Molin Qin; Chenghai Guo; Mingyu Ding

    2015-01-01

    Hydrogen-bond acidic polymers are important high affinity materials sensitive to organophosphates in the chemical warfare agent sensor detection process. Interactions between the sensor sensitive materials and chemical warfare agent simulants were studied by inverse gas chromatography. Hydrogen bonded acidic polymers, i.e., BSP3, were prepared for micro-packed columns to examine the interaction. DMMP (a nerve gas simulant) and 2-CEES (a blister agent simulant) were used as probes. Chemical an...

  9. Fatty acid constituents of Peganum harmala plant using Gas Chromatography-Mass Spectroscopy.

    Moussa, Tarek A A; Almaghrabi, Omar A

    2016-05-01

    Fatty acid contents of the Peganum harmala plant as a result of hexane extraction were analyzed using GC-MS. The saturated fatty acid composition of the harmal plant was tetradecanoic, pentadecanoic, tridecanoic, hexadecanoic, heptadecanoic and octadecanoic acids, while the saturated fatty acid derivatives were 12-methyl tetradecanoic, 5,9,13-trimethyl tetradecanoic and 2-methyl octadecanoic acids. The most abundant fatty acid was hexadecanoic with concentration 48.13% followed by octadecanoic with concentration 13.80%. There are four unsaturated fatty acids called (E)-9-dodecenoic, (Z)-9-hexadecenoic, (Z,Z)-9,12-octadecadienoic and (Z,Z,Z)-9,12,15-octadecatrienoic. The most abundant unsaturated fatty acid was (Z,Z,Z)-9,12,15-octadecatrienoic with concentration 14.79% followed by (Z,Z)-9,12-octadecadienoic with concentration 10.61%. Also, there are eight non-fatty acid compounds 1-octadecene, 6,10,14-trimethyl-2-pentadecanone, (E)-15-heptadecenal, oxacyclohexadecan-2 one, 1,2,2,6,8-pentamethyl-7-oxabicyclo[4.3.1]dec-8-en-10-one, hexadecane-1,2-diol, n-heneicosane and eicosan-3-ol. PMID:27081366

  10. Gas Chromatography Analysis of Resin and Fatty Acids from Laboratory Generated Bleach Plant Effluents

    Chhaya Sharma; S. Mohanty; S. Kumar; N.J. Rao

    2007-01-01

    Laboratory generated spent bleached liquor from the chlorination, caustic extraction stage of mixed wood kraft pulp processing has been analyzed both qualitatively and quantitatively for various resin & fatty acids by using GC. A number of resin acids,saturated and unsaturated fatty acids, chloro fatty and resin acid have been detected and their concentrations are estimated. The results are compared with results on different agriculture residue/hardwood pulps, which were reported earlier. The concentrations of various compounds detected have also been compared with their reported LC50 values.

  11. Effects of acid conditions on elemental distribution beneath a sulphur block at a sour gas plant in Alberta

    The effect of sulphur blocks on soil and groundwater systems was discussed. Sulphur extracted from sour natural gas is stored in large blocks directly on the ground. The elemental sulphur will oxidize to H2SO4 under aerobic conditions and with the proper microorganisms, resulting in possible removal of metals from the soil and transportation in the groundwater. A recent study showed that a 10-15 cm thick, oxyhydroxide indurated layer was present at the edge of a 25 year old sulphur block at a sour gas plant in southern Alberta. Another study was conducted to determine the effects of acid conditions beneath a 36 year old sulphur block at another site. The objective was to locate the indurated layer using geophysical techniques and soil boring. The extent of acid conditions beneath the sulphur block, and the elemental distribution in soil and groundwater were determined. The estimated migration rates for the two sites were 0.44 cm/yr and 0.75 cm/yr respectively. The data implied that minimal soil and groundwater impact can be expected from sulphur blocks overlying properly buffered soils. Therefore, it was proposed that synthetic liners beneath sulphur blocks may not be a necessary mitigative measure at sour gas plants in Alberta

  12. Deprotonation of p-Hydroxybenzoic Acid: Does Electrospray Ionization Sample Solution or Gas-Phase Structures?

    Schröder, Detlef; Buděšínský, Miloš; Roithová, J.

    2012-01-01

    Roč. 134, č. 38 (2012), s. 15897-15905. ISSN 0002-7863 Grant ostatní: European Research Council(XE) AdG HORIZOMS Institutional support: RVO:61388963 Keywords : mobility-mass-spectrometry * 4-hydroxybenzoic acid * air/water interfase * DFT calculations * aqueous-solution * benzoic-acids Subject RIV: CC - Organic Chemistry Impact factor: 10.677, year: 2012

  13. 酸气回注工艺及其技术优势分析%Analysis on Acid Gas Reinjection Process and Its Technical Advantages

    陈锐; 张坤勋; 朱铭; 张锐悦; 宁雯宇

    2013-01-01

      随着酸性天然气田的大规模开发,天然气净化产生的酸气量急剧增加,而环保要求日趋严格,给酸气的后处理带来巨大压力。受全球硫磺市场供过于求的影响,硫磺价格下跌,传统的硫磺回收法处理酸气的工艺经济效益变差,因此酸气回注技术越来越受到重视。回顾了国外酸气回注工艺的发展现状,系统介绍了酸气回注的选址和工艺流程等问题。以中东卡塔尔国家Khuff气田天然气净化厂的两种酸气处理工艺为例,从工艺设施、投资费用、环保、工艺适用范围四方面进行了对比分析,得出酸气回注工艺技术的优越性,并结合国内油气田具体情况,给出了相应建议。%With the large-scale development of the sour gas field, the amount of acid gas generated from natural gas purification increases dramatically. The environmental protection request is more and more strict, which will bring enormous pressure to the post-processing of acid gas. Because the global sulfur market oversupplies, price of sulfur falls down, and economic benefits of treating acid gas by the traditional sulfur recovery method declines. Another new acid gas reinjection technology in the treatment of acid gas has been paid more and more attention. In this paper, the development status of foreign acid gas reinjection processes was reviewed, and the problems about acid gas reinjection processes including site selection and process flow were discussed. In addition, taking two kinds of sour gas treatment processes in Khuff gas field in Qatar as an example, and a comparative analysis was carried out from four aspects of process facilities, investment, environmental protection and technology application scope, advantages of the acid gas reinjection technology were pointed out, and relevant suggestions were put forward combined with the specific situation of domestic oil and gas fields.

  14. Fatty acid profiling of raw human plasma and whole blood using direct thermal desorption combined with gas chromatography-mass spectrometry

    Akoto, Lawrence; Vreuls, Rene J. J.; Irth, Hubertus; Pel, Roel; Stellaard, Frans

    2008-01-01

    Gas chromatography (GC) has in recent times become an important tool for the fatty acid profiling of human blood and plasma. An at-line procedure used in the fatty acid profiling of whole/intact aquatic micro-organisms without any sample preparation was adapted for this work. A direct thermal desorp

  15. Fatty acid profiling of raw human plasma and whole blood using direct thermal desorption combined with gas chromatography–mass spectrometry

    Akoto, L.; Vreuls, R.J.J.; Irth, H.; Pel, R.; Stellaard, F.

    2008-01-01

    Gas chromatography (GC) has in recent times become an important tool for the fatty acid profiling of human blood and plasma. An at-line procedure used in the fatty acid profiling of whole/intact aquatic micro-organisms without any sample preparation was adapted for this work. A direct thermal desorp

  16. Exploring the Ideal Gas Law through a Quantitative Gasometric Analysis of Nitrogen Produced by the Reaction of Sodium Nitrite with Sulfamic Acid

    Yu, Anne

    2010-01-01

    The gasometric analysis of nitrogen produced in a reaction between sodium nitrite, NaNO[superscript 2], and sulfamic acid, H(NH[superscript 2])SO[superscript 3], provides an alternative to more common general chemistry experiments used to study the ideal gas law, such as the experiment in which magnesium is reacted with hydrochloric acid. This…

  17. THE MATHEMATIC SIMULATION PROCESS OF TOXIC GAS WICKING INTO THE ROOM THROUGH THE VENTILATION SYSTEM ON THE TERRITORY OF CHEMICALLY HAZARDOUS OBJECT DURING THE EMERGENCY

    M. M. Biliaiev

    2011-05-01

    Full Text Available The 3D-numerical model to simulate the toxic gas dispersion on industrial sites and inflow of toxic gas into the industrial room after accident ejections was developed. The model is based on the K-gradient transport model and equation of potential flow. The results of numerical experiment are presented.

  18. Sulfur Recovery from Acid Gas Using the Claus Process and High Temperature Air Combustion (HiTAC Technology

    Mohamed Sassi

    2008-01-01

    Full Text Available Sulfur-bearing compounds are very detrimental to the environment and to industrial process equipment. They are often obtained or formed as a by-product of separation and thermal processing of fuels containing sulfur, such as coal, crude oil and natural gas. The two sulfur compounds, which need special attention, are: hydrogen sulfide (H2S and sulfur dioxide (SO2. H2S is a highly corrosive gas with a foul smell. SO2 is a toxic gas responsible for acid rain formation and equipment corrosion. Various methods of reducing pollutants containing sulfur are described in this paper, with a focus on the modified Claus process, enhanced by the use of High Temperature Air Combustion (HiTAC technology in the Claus furnace. The Claus process has been known and used in the industry for over 100 years. It involves thermal oxidation of hydrogen sulfide and its reaction with sulfur dioxide to form sulfur and water vapor. This process is equilibrium-limited and usually achieves efficiencies in the range of 94-97%, which have been regarded as acceptable in the past years. Nowadays strict air pollution regulations regarding hydrogen sulfide and sulfur dioxide emissions call for nearly 100% efficiency, which can only be achieved with process modifications. High temperature air combustion technology or otherwise called flameless (or colorless combustion is proposed here for application in Claus furnaces, especially those employing lean acid gas streams, which cannot be burned without the use of auxiliary fuel or oxygen enrichment under standard conditions. With the use of HiTAC it has been shown, however, that fuel-lean, Low Calorific Value (LCV fuels can be burned with very uniform thermal fields without the need for fuel enrichment or oxygen addition. The uniform temperature distribution favors clean and efficient burning with an additional advantage of significant reduction of NOx, CO and hydrocarbon emission.

  19. Peak alignment and robust principal component analysis of gas chromatograms of fatty acid methyl esters and volatiles

    Frosch, Stina; Jørgensen, Bo

    2007-01-01

    Gas chromatograms of fatty acid methyl esters and of volatile lipid oxidation products from fish lipid extracts are analyzed by multivariate data analysis [principal component analysis (PCA)]. Peak alignment is necessary in order to include all sampled points of the chromatograms in the data set....... The ability of robust algorithms to deal with outlier problems, including both sample-wise and element-wise outliers, and the advantages and drawbacks of two robust PCA methods, robust PCA (ROBPCA) and robust singular value decomposition when analysing these GC data were investigated. The results show...

  20. Gas chromatography determination of fatty acid alkyl esters (methyl and ethyl in the presence of mono., di- and triglycerides

    Paulo César Narváez Rincón

    2010-04-01

    Full Text Available Determining fatty acid methyl or ethyl esters, in the presence of mono-, di- and tri glycerides, is very important when studying fatty compounds' methanolysis or ethanolysis, as well as for controlling the quality of petrochemical products. This work presents a useful technique for determining fatty acids methyl or ethyl esters by high temperature gas chromastography in the presence of mono-, di- and triglycerides. Samples were silylated with N, O-bis (trimethylsilyl trifluroacetamide (BSTFA and then passed throught a 12m HT5 column coated with a phenyl-polysiloxane-carborane film. Standard methyl and ethyl palmitate, methyl and ethyl oleate, DL-palmitin, dipalmitin, tripalmitin and triolein solutions were used for calibrating the technique, using tricaprin as internal standard. Retention times and response factors were also determined. The results were employed in following-up palm oil methanolysis and ethanolysis reactions.

  1. Research on the Interaction of Hydrogen-Bond Acidic Polymer Sensitive Sensor Materials with Chemical Warfare Agents Simulants by Inverse Gas Chromatography

    Liu Yang

    2015-06-01

    Full Text Available Hydrogen-bond acidic polymers are important high affinity materials sensitive to organophosphates in the chemical warfare agent sensor detection process. Interactions between the sensor sensitive materials and chemical warfare agent simulants were studied by inverse gas chromatography. Hydrogen bonded acidic polymers, i.e., BSP3, were prepared for micro-packed columns to examine the interaction. DMMP (a nerve gas simulant and 2-CEES (a blister agent simulant were used as probes. Chemical and physical parameters such as heats of absorption and Henry constants of the polymers to DMMP and 2-CEES were determined by inverse gas chromatography. Details concerning absorption performance are also discussed in this paper.

  2. Research on the interaction of hydrogen-bond acidic polymer sensitive sensor materials with chemical warfare agents simulants by inverse gas chromatography.

    Yang, Liu; Han, Qiang; Cao, Shuya; Huang, Feng; Qin, Molin; Guo, Chenghai; Ding, Mingyu

    2015-01-01

    Hydrogen-bond acidic polymers are important high affinity materials sensitive to organophosphates in the chemical warfare agent sensor detection process. Interactions between the sensor sensitive materials and chemical warfare agent simulants were studied by inverse gas chromatography. Hydrogen bonded acidic polymers, i.e., BSP3, were prepared for micro-packed columns to examine the interaction. DMMP (a nerve gas simulant) and 2-CEES (a blister agent simulant) were used as probes. Chemical and physical parameters such as heats of absorption and Henry constants of the polymers to DMMP and 2-CEES were determined by inverse gas chromatography. Details concerning absorption performance are also discussed in this paper. PMID:26043177

  3. Direct Automatic Bacterial Analysis of Rat Stool Samples; The Effects of Diet and Medical Treatment Studied by Computerised Gas-liquid Chromatography of Bacterial Fatty Acids

    Peltonen, R; Eerola, E

    2011-01-01

    Gas-liquid chromatography (GLC) of bacterial cellular fatty acids was used to produce fatty acid profiles of the stool samples of six different groups of rats, three with different medications, two with experimental diets and a control group with ordinary laboratory food. Such a profile represents all the bacterial cellular fatty acids in the sample and thus reflects its microflora. The profiles were then compared to each other in order to test the applicability of the GLC method for simple a...

  4. Gas-particle partitioning of organic acids during the Southern Oxidant and Aerosol Study (SOAS): measurements and modeling

    Thompson, S.; Yatavelli, R.; Stark, H.; Kimmel, J.; Krechmer, J.; Day, D. A.; Isaacman, G. A.; Goldstein, A. H.; Khan, M. A. H.; Holzinger, R.; Lopez-Hilfiker, F.; Mohr, C.; Thornton, J. A.; Jayne, J. T.; Worsnop, D. R.; Jimenez, J. L.

    2014-12-01

    Gas-Particle partitioning measurements of organic acids were carried out during the Southern Oxidant and Aerosol Study (SOAS, June-July 2013) at the Centerville, AL Supersite in the Southeast US, a region with significant isoprene and terpene emissions. Organic acid measurements were made with a Chemical Ionization High Resolution Time-of-Flight Mass Spectrometer (HRToF-CIMS) with a Filter Inlet for Gases and AEROsols (FIGAERO) and acetate (CH3COO-) as the reagent ion. We investigate both individual species and bulk organic acids and partitioning to organic and water phases in the aerosol. Measured partitioning is compared to data from three other instruments that can also quantify gas-particle partitioning with high time resolution: another HRToF-CIMS using iodide (I-) as the reagent ion to ionize acids and other highly oxidized compounds, a Semivolatile Thermal Desorption Aerosol GC/MS (SV-TAG), and a Thermal Desorption Proton Transfer Time-of-Flight Mass Spectrometer (TD-PTRMS The partitioning measurements for three of the instruments are generally consistent, with results in the same range for most species and following similar temporal trends and diurnal cycles. The TD-PTRMS measures on average ½ the partitioning to the particle phase of the acetate CIMS. Both the measurements and the model of partitioning to the organic phase respond quickly to temperature, and the model agrees with the measured partitioning within the error of the measurement for multiple compounds, although many compounds do not match the modeled partitioning, especially at lower m/z. This discrepancy may be due to thermal decomposition of larger molecules into smaller ones when heated.

  5. Characterization of Fatty Acid Profile of Argan Oil and Other Edible Vegetable Oils by Gas Chromatography and Discriminant Analysis

    Ascensión Rueda

    2014-01-01

    Full Text Available Virgin argan oil is an emergent oil that is being introduced into specialized international markets as a healthy and luxury food. In order to compare the fatty acid composition of argan oil with that of the eleven other vegetable edible oils, a combination of gas chromatography as analytical technique and multivariate discriminant analysis was applied. This analysis takes into account the conjoint effect of all the variables analyzed in the discrimination between oils and also shows the contribution of each variable to oils characterization. The model correctly classified 100% oil samples. According to the fatty acid composition, argan oil showed closest similarity firstly with sesame oil and secondly with high oleic sunflower oil. Olive oil was close to avocado oil and almond oil, followed by argan oil. Thus, similarities and differences between vegetable oils based on their fatty acid profile were established by the application of multivariate discriminant analysis. This method was proven to be a useful tool to study the relationships between oils according to the fat composition and to determine the importance of the fatty acid variables on the oils classification.

  6. 水和弱酸对过氧化氢异丙苯热危险性的影响%Influence of water and weak acid on thermal hazard of cumene hydroperoxide

    金满平; 孙峰; 石宁; 谢传欣

    2012-01-01

    In order to study the influence of water and weak acid on the thermal hazard of cumene hydroperoxide (CHP) ,the thermal decomposition of CHP and CHP mixtures with different contents of water and weak acid and different pH of weak acid in the air was studied by C600 calorimeter. The corresponding kinetic and thermodynamic parameters based on experimental data were obtained,and the Semenov model was used to calculate the self accelerating decomposition temperature (SADT). The results show that small amounts of water and weak acid reduce the initial exothermic temperature,peak exothermic temperature and activation energy. The pH of weak acid also affects thermal hazard of CHP. As the pH of weak acid decreases,it is easier for the CHP decomposition reaction to occur. Calculated SADT of CHP is 84℃. The comparison on the calculated SADT results indicates that small amounts of water and weak acid reduce the SADT of CHP,and at lower pH of weak acid,the SADT also decreases.%为研究水和弱酸对过氧化氢异丙苯(CHP)热危险性的影响,利用C600微量热仪研究了CHP及CHP与不同含量水、不同含量弱酸、不同pH值弱酸的混合物在空气中受热分解的反应和放热特性,根据实验数据得出了相应的动力学和热力学参数,利用Semenov热爆炸模型计算出了自加速分解温度(SADT).结果表明:少量的水和弱酸都能够使CHP的起始放热温度、最大放热温度、活化能降低;弱酸的pH值对CHP的热危险性也有影响,pH值越低,CHP的热危险性越大;计算得到CHP的SADT为84℃,通过对CHP及CHP与不同含量水、弱酸和不同pH值弱酸混合物SADT进行比较,发现少量的水和弱酸均能降低CHP的SADT,弱酸的pH值对SADT也有影响,pH值越低,CHP与弱酸混合物的SADT越小.

  7. Kinetics of gas phase formic acid decomposition on platinum single crystal and polycrystalline surfaces

    Detwiler, Michael D.; Milligan, Cory A.; Zemlyanov, Dmitry Y.; Delgass, W. Nicholas; Ribeiro, Fabio H.

    2016-06-01

    Formic acid dehydrogenation turnover rates (TORs) were measured on Pt(111), Pt(100), and polycrystalline Pt foil surfaces at a total pressure of 800 Torr between 413 and 513 K in a batch reactor connected to an ultra-high vacuum (UHV) system. The TORs, apparent activation energies, and reaction orders are not sensitive to the structure of the Pt surface, within the precision of the measurements. CO introduced into the batch reactor depressed the formic acid dehydrogenation TOR and increased the reaction's apparent activation energies on Pt(111) and Pt(100), consistent with behavior predicted by the Temkin equation. Two reaction mechanisms were explored which explain the formic acid decomposition mechanism on Pt, both of which include dissociative adsorption of formic acid, rate limiting formate decomposition, and quasi-equilibrated hydrogen recombination and CO adsorption. No evidence was found that catalytic supports used in previous studies altered the reaction kinetics or mechanism.

  8. Acidity enhances the formation of a persistent ozonide at aqueous ascorbate/ozone gas interfaces

    Enami, Shinichi; Hoffmann, M. R.; Colussi, A. J.

    2008-01-01

    The pulmonary epithelium, like most aerial biosurfaces, is naturally protected against atmospheric ozone (O3) by fluid films that contain ascorbic acid (AH2) and related scavengers. This mechanism of protection will fail, however, if specific copollutants redirect AH2 and O3(g) to produce species that can transduce oxidative damage to underlying tissues. Here, the possibility that the synergistic adverse health effects of atmospheric O3(g) and acidic particulate matter revealed by epidemiolog...

  9. NASA Hazard Analysis Process

    Deckert, George

    2010-01-01

    This viewgraph presentation reviews The NASA Hazard Analysis process. The contents include: 1) Significant Incidents and Close Calls in Human Spaceflight; 2) Subsystem Safety Engineering Through the Project Life Cycle; 3) The Risk Informed Design Process; 4) Types of NASA Hazard Analysis; 5) Preliminary Hazard Analysis (PHA); 6) Hazard Analysis Process; 7) Identify Hazardous Conditions; 8) Consider All Interfaces; 9) Work a Preliminary Hazard List; 10) NASA Generic Hazards List; and 11) Final Thoughts

  10. Auditing hazardous waste incineration

    This paper reports that audit standards consisting of volatile and semivoltile organics have been established by the EPA to be provided to federal, state, and local agencies or their contractors for use in performance audits to assess the accuracy of measurement methods used during hazardous waste trial burns. The volatile organic audit standards currently total 29 gaseous organics in 5, 6, 7, 9, and 18-component mixtures at part-per-billion (ppb) levels (1 to 10 000 ppb) in compressed gas cylinders in a balance gas of nitrogen. The semivoltile organic audit standards currently total six organics which are spiked onto XAD-2 cartridges for auditing analysis procedures. Studies of all organic standards have been performed to determine the stability of the compounds and the feasibility of using them as performance audit materials. Results as of July 1987 indicate that all of the selected organic compounds are adequately stabile for use as reliable audit materials. Performance audits have been conducted with the audit materials to assess the accuracy of the measurement methods. To date, 160 performance audits have been initiated with the ppb-level audit gases. The audit results obtained with audit gases during hazardous waste trial burn tests were generally within ±50% of the audit concentrations. A limited number of audit results have been obtained with spiked XAD-2 cartridges, and the results have generally been within ±35% of the audit concentrations

  11. Effect of thermal annealing on a novel polyamide–imide polymer membrane for aggressive acid gas separations

    Vaughn, Justin T.

    2012-05-01

    A fluorinated, 6FDA based polyamide-imide is investigated for the purification of CH 4 from CO 2 and H 2S containing gas streams. Dense polymer films were thermally annealed and showed that increased annealing temperatures at constant annealing time caused transport behavior that does not resemble physical aging. Free volume increased after annealing at 200°C for 24h relative to annealing at 150°C for the same time. CO 2 and CH 4 permeabilities and diffusivities did not decrease as a result of the higher annealing temperature, and in fact, were shown to increase slightly. A change to the intrinsic microstructure that cannot be described by simple, densification based physical aging is hypothesized to be the reason for this trend. Furthermore, annealing increased CO 2 induced plasticization resistance and a temperature of 200°C was shown to have the greatest effect on plasticization suppression. Annealing at 200°C for 24h suppressed pure gas CO 2 plasticization up to 450psia. Fluorescence spectroscopy revealed increased intramolecular charge transfer, which is presumably due to increased electron conjugation over the N-phenyl bond. Additionally, intermolecular charge transfer increased with thermal annealing, as inferred from fluorescence intensity measurements and XRD patterns. 50/50 CO 2/CH 4 mixed gas permeation measurements reveal stable separation performance up to 1000psia. Ternary mixed gas feeds containing toluene/CO 2/CH 4 and H 2S/CO 2/CH 4 show antiplasticization, but more importantly, selectivity losses due to plasticization did not occur up to 900psia of total feed pressure. These results show that the polyamide-imide family represents a promising class of separation materials for aggressive acid gas purifications. © 2012 Elsevier B.V.

  12. Greenhouse gas reduction and improved sustainability of animal husbandry using amino acids in swine, poultry feeds.

    Tsujimoto, Susumu; Takagi, Tomo; Osada, Takashi; Ogino, Akifumi

    2013-05-01

    In Annex 1 countries, nitrous oxide (N2 O) emissions from swine and poultry excreta have been calculated and the N2 O reduction potential of each country by using amino acids in feed could also be calculated, then a comparison made among the countries. The N2 O reduction rates were approximately 25% for these Annex 1 countries and amino acids were able to make a large contribution to that reduction. Greenhouse gases (GHG) which are N2 O combined with methane (CH4 ) were estimated to reduce by 24.8% in Japan when amino acids were introduced into the feed, but only a 7.2% reduction was estimated in France. Purification, which is mainly used for manure treatment in Japan, emits much more N2 O and less CH4 , whereas the liquid system which is mainly used in France emits more CH4 and less N2 O based on the emission factors from the United Nations Framework Convention on Climate Change data base. Changing the French manure treatment system to the Japanese style with amino acids in feed would reduce GHG emissions by 23.4%. Reduction of the arable land use in Japan by changing crop formulations supported by adding amino acids to feed was also quantified as about 10% and led to an increase in the production of meat using the same arable land area. PMID:23607750

  13. Radiation hazard

    Radiation hazards to infants in the treatment of malignant tumor were discussed. Late effects of radiotherapy in infants became an important problem in an increasing number of cases with prolonged survival periods. Late effects of radiotherapy included tumor and leukemia induction, as well as disturbance of growth in the eyes, bone, etc. In order to avoid iatrogenic disorders, physicians should be required to have adequate knowledge of the anatomy and physiology of normal tissue, and variations with age. Pathology of tumors and the condition of patients before and after resection should be thoroughly understood. To determine normal tissue tolerance dose, various function tests, especially radiological examinations, are required. Suspected tissue should be frequently biopsied, and clinical observations should also be frequent. Postoperative irradiation should be selected depending on the kind of lesion. In treatment, the younger the patient is, the less should be the dose applied, and the longer the overall time of application. Fields should be limited to an area somewhat larger than the tumor lesion except in the case of malignant lymphoma, when anticancer drugs are combined with radiotherapy. It is difficult to determine the normal tissue tolerance dose, and tolerance dose of normal infant tissue differs considerably by age. Based on the author's experience, tolerance doses for skin, brain, spinal cord, eyes, face, cervical area, and extremities were demonstrated. (S. MUKOHATA)

  14. Influence of different storage times and temperatures on blood gas and acid-base balance in ovine venous blood

    H.A. Hussein

    2013-01-01

    Full Text Available The present study was designed to investigate the effects of storage temperature and time on blood gas and acid-base balance of ovine venous blood. Ten clinically healthy sheep were used in this study. A total number of 30 blood samples, were divided into three different groups, and were stored in a refrigerator adjusted to +4 ºC (Group I, n = 10, at RT of about 22-25 ºC (Group II, n = 10 and in an incubator adjusted to 37 ºC (Group III, n = 10 for up to 48 h. Blood samples were analysed for blood gas and acid-base indices at 0, 1, 2, 3, 4, 5, 6, 12, 24 and 48 h of storage. In comparison to the baseline value (0, there were significant decreases of blood pH of samples stored at RT and in the incubator after 1 h (p<0.05, the pH value of refrigerated blood samples exhibited insignificant changes during the study (p<0.05. Mean values of pCO2 showed a significant increase in Group I and Group III after 1 h then a progressive decrease after 12 h in all Groups. Mean pO2 values were significantly higher for Group I after 2 h and for Groups II and III after 1 h (p<0.05. In general, base excess decreased significantly for all the groups during the study especially in Groups II and III. In comparison with baseline values, in all groups, bicarbonate (HCO3 increased between 1 h and 6 h (p<0.05, and later decreased at the end of the study (p<0.05. In conclusion, status of acid-base indices of the samples stored at refrigerator and RT were found within normal reference range and it may be of clinical diagnostic use for up to 6 h.

  15. An Experimental and Computational Investigation into the Gas-Phase Acidities of Tyrosine and Phenylalanine: Three Structures for Deprotonated Tyrosine

    Bokatzian, Samantha S.; Stover, Michele L.; Plummer, Chelsea E.; Dixon, David A.; Cassady, Carolyn J.

    2014-11-06

    Using mass spectrometry and correlated molecular orbital theory, three deprotonated structures were revealed for the amino acid tyrosine. The structures were distinguished experimentally by ion/molecule reactions involving proton transfer and trimethylsilyl azide. Gas-phase acidities from proton transfer reactions and from G3(MP2) calculations generally agree well. The lowest energy structure, which was only observed experimentally using electrospray ionization from aprotic solvents, is deprotonated at the carboxylic acid group and is predicted to be highly folded. A second unfolded carboxylate structure is several kcal/mol higher in energy and primarily forms from protic solvents. Protic solvents also yield a structure deprotonated at the phenolic side chain, which experiments find to be intermediate in energy to the two carboxylate forms. G3(MP2) calculations indicate that the three structures differ in energy by only 2.5 kcal/mol, yet they are readily distinguished experimentally. Structural abundance ratios are dependent upon experimental conditions, including the solvent and accumulation time of ions in a hexapole. Under some conditions, carboxylate ions may convert to phenolate ions. For phenylalanine, which lacks a phenolic group, only one deprotonated structure was observed experimentally when electrosprayed from protic solvent. This agrees with G3(MP2) calculations that find the folded and unfolded carboxylate forms to differ by 0.3 kcal/mol.

  16. Profiling fatty acids in vegetable oils by reactive pyrolysis-gas chromatography with dimethyl carbonate and titanium silicate.

    Fabbri, Daniele; Baravelli, Valentina; Chiavari, Giuseppe; Prati, Silvia

    2005-12-30

    A novel methodology in on-line pyrolysis-gas chromatography (Py-GC) for the fast analysis of fatty acids in vegetable oils with minimal sample treatment and the use of non-toxic reagents is described. Pyrolysis at 500 degrees C for 10 s of sub-microgram quantity of vegetable oil dissolved in dimethyl carbonate (DMC) and in the presence of nanopowder titanium silicon oxide resulted in the production of fatty acid methyl esters (FAMEs) as unique products. Pyrolysis performed by means of a resistively heated filament pyrolyser interfaced to a GC-MS apparatus enabled the direct analysis of evolved FAMEs. The DMC/Py-GC-MS analysis was tested on soybean, coconut, linseed, walnut and olive oil and the results compared to the classical BF(3)-methanol as reference methodology. The DMC method exhibited a lower precision and was biased towards lower levels of polyunsaturated fatty acids (PUFA) in comparison to the BF(3)-methanol method, but was more advantageous in terms of reduced sample treatment, waste generation and risk factors of employed chemicals. PMID:16216255

  17. Regeneration of spent three-way catalysts with nano-structured platinum group metals by gas and acid treatments.

    Kim, Sang Chai; Nahm, Seung Won; Wang, Geun Shim; Seo, Seong Gyu; Lee, Jae Wook

    2008-10-01

    The influence of physicochemical treatments on the catalytic activity of the spent nano-structured three way catalysts (TWCs) was examined to evaluate the possibility of using spent TWCs for removing VOCs. Thermal gases and acid aqueous solutions were used to regenerate the spent nano-structured TWCs. The characterization of the spent catalyst and its modified forms was carried out by using XRD, TEM, ICP, and N2 adsorption-desorption isotherms. The catalytic activity tests revealed that the spent nano-structured TWCs have a great potential for removing toxic compounds. The activities of catalysts were also found to be highly dependent on the treatment conditions. The acid aqueous treatments were very useful for improving the catalytic activity because they removed various contaminants such as fuel additives, lubricant oil additives, and metallic compounds. However, the thermal gas treated TWCs were less active than the parent TWCs. Furthermore, the activities of the catalysts treated with acids were closely connected with the remaining Pt/Al ratios. PMID:19198464

  18. The Chemistry Scoring Index (CSI): A Hazard-Based Scoring and Ranking Tool for Chemicals and Products Used in the Oil and Gas Industry

    Tim Verslycke; Kim Reid; Teresa Bowers; Sagar Thakali; Ari Lewis; Johnny Sanders; Denise Tuck

    2014-01-01

    A large portfolio of chemicals and products is needed to meet the wide range of performance requirements of the oil and gas industry. The oil and gas industry is under increased scrutiny from regulators, environmental groups, the public, and other stakeholders for use of their chemicals. In response, industry is increasingly incorporating “greener†products and practices but is struggling to define and quantify what exactly constitutes “green†in the absence of a universally accepted de...

  19. Mechanisms controlling the leaching kinetics of fixated flue gas desulfurization (FGD) material under neutral and acidic conditions.

    Cheng, Chin-Min; Walker, Harold W; Bigham, Jerry M

    2007-01-01

    A number of agricultural and engineering uses for fixated flue gas desulfurization (FGD) material exist; however, the potential for leaching of hazardous elements has limited widespread application and the processes controlling the leaching of this material are poorly understood. In this study, a flow-through rotating-disk system was applied to elucidate the relative importance of bulk diffusion, pore diffusion, and surface chemical reaction in controlling the leaching of fixated FGD material under pH conditions ranging from 2.2 to 6.8. Changing the hydrodynamics in the rotating disk system did not affect the leaching kinetics at both pH 2.2 and 6.8, indicating that bulk diffusion was not the kinetic-limiting step. Application of the shrinking core model (SCM) to the data suggested a surface reaction-controlled mechanism, rather than a pore diffusion mechanism. The leaching of fixated FGD material increased with decreasing pH, suggesting it can be described by a combination of an intrinsic hydration reaction and a proton-promoted dissolution reaction. X-ray diffraction (XRD) and elemental composition analyses before and after leaching suggests that for most elements a number of solid phases controlled the leaching process. PMID:17485719

  20. Gas Chromatographic Determination of Sulfuric Acid and Application to Urinary Sulfate

    Masuoka,Noriyoshi

    1988-10-01

    Full Text Available A new gas chromatographic method for the determination of sulfate was developed. In this method, sulfate was quantitatively converted to a volatile derivative, dimethyl sulfate, by a two-step procedure. First, sulfate was converted to silver sulfate by reaction with silver oxide, and then to dimethyl sulfate by reaction with methyl iodide. The derivative was analyzed by gas chromatography. Methyl methanesulfonate was used as an internal standard. The method was applied to the determination of total urinary sulfate. Phosphate and chloride ions, which interfered with the present method, were eliminated with the use of basic magnesium carbonate and an excess of silver oxide, respectively. Recovery was over 96% when 5 to 40 mumol/ml of sulfate was added to human urine samples.

  1. Hazard classification methodology

    This document outlines the hazard classification methodology used to determine the hazard classification of the NIF LTAB, OAB, and the support facilities on the basis of radionuclides and chemicals. The hazard classification determines the safety analysis requirements for a facility

  2. Hazard analysis in uranium hexafluoride production facility

    The present work provides a method for preliminary hazard analysis of nuclear fuel cycle facilities. The proposed method identify both chemical and radiological hazards, as well as the consequences associated with accident scenarios. To illustrate the application of the method, a uranium hexafluoride production facility was selected. The main hazards are identified and the potential consequences are quantified. It was found that, although the facility handles radioactive material, the main hazards as associated with releases of toxic chemical substances such as hydrogen fluoride, anhydrous ammonia and nitric acid. It was shown that a contention bung can effectively reduce the consequences of atmospheric release of toxic materials. (author)

  3. Characterisation of polycyclic aromatic hydrocarbons in flue gas and residues of a full scale fluidized bed combustor combusting non-hazardous industrial waste.

    Van Caneghem, J; Vandecasteele, C

    2014-11-01

    This paper studies the fate of PAHs in full scale incinerators by analysing the concentration of the 16 EPA-PAHs in both the input waste and all the outputs of a full scale Fluidized Bed Combustor (FBC). Of the analysed waste inputs i.e. Waste Water Treatment (WWT) sludge, Refuse Derived Fuel (RDF) and Automotive Shredder Residue (ASR), RDF and ASR were the main PAH sources, with phenanthrene, fluoranthene and pyrene being the most important PAHs. In the flue gas sampled at the stack, naphthalene was the only predominant PAH, indicating that the PAHs in FBC's combustion gas were newly formed and did not remain from the input waste. Of the other outputs, the boiler and fly ash contained no detectable levels of PAHs, whereas the flue gas cleaning residue contained only low concentrations of naphthalene, probably adsorbed from the flue gas. The PAH fingerprint of the bottom ash corresponded rather well to the PAH fingerprint of the RDF and ASR, indicating that the PAHs in this output, in contrast to the other outputs, were mainly remainders from the PAHs in the waste inputs. A PAH mass balance showed that the total PAH input/output ratio of the FBC ranged from about 100 to about 2600 depending on the waste input composition and the obtained combustion conditions. In all cases, the FBC was clearly a net PAH sink. PMID:25002370

  4. Survival of gas phase amino acids and nucleobases in space radiation conditions

    Pilling, S; de Castilho, R B; Cavasso-Filho, R L; Lago, A F; Coutinho, L H; de Souza, G G B; Boechat-Roberty, H M; de Brito, A Naves

    2008-01-01

    We present experimental studies on the photoionization and photodissociation processes (photodestruction) of gaseous amino acids and nucleobases in interstellar and interplanetary radiation conditions analogs. The measurements have been undertaken at the Brazilian Synchrotron Light Laboratory (LNLS), employing vacuum ultraviolet (VUV) and soft X-ray photons. The experimental set up basically consists of a time-of-flight mass spectrometer kept under high vacuum conditions. Mass spectra were obtained using photoelectron photoion coincidence technique. We have shown that the amino acids are effectively more destroyed (up to 70-80%) by the stellar radiation than the nucleobases, mainly in the VUV. Since polycyclic aromatic hydrocarbons have the same survival capability and seem to be ubiquitous in the ISM, it is not unreasonable to predict that nucleobases could survive in the interstellar medium and/or in comets, even as a stable cation.

  5. Kinetic and equilibrium study on formic acid decomposition in relation to the water-gas-shift reaction.

    Yasaka, Yoshiro; Yoshida, Ken; Wakai, Chihiro; Matubayasi, Nobuyuki; Nakahara, Masaru

    2006-09-28

    Kinetics and equilibrium are studied on the hydrothermal decarbonylation and decarboxylation of formic acid, the intermediate of the water-gas-shift (WGS) reaction, in hot water at temperatures of 170-330 degrees C, to understand and control the hydrothermal WGS reaction. (1)H and (13)C NMR spectroscopy is applied to analyze as a function of time the quenched reaction mixtures in both the liquid and gas phases. Only the decarbonylation is catalyzed by HCl, and the reaction is first-order with respect to both [H(+)] and [HCOOH]. Consequently, the reaction without HCl is first and a half (1.5) order due to the unsuppressed ionization of formic acid. The HCl-accelerated decarbonylation path can thus be separated in time from the decarboxylation. The rate and equilibrium constants for the decarbonylation are determined separately by using the Henry constant (gas solubility data) for carbon monoxide in hot water. The rate constant for the decarbonylation is 1.5 x 10(-5), 2.0 x 10(-4), 3.7 x 10(-3), and 6.3 x 10(-2) mol(-1) kg s(-1), respectively, at 170, 200, 240, and 280 degrees C on the liquid branch of the saturation curve. The Arrhenius plot of the decarbonylation is linear and gives the activation energy as 146 +/- 3 kJ mol(-1). The equilibrium constant K(CO) = [CO]/[HCOOH] is 0.15, 0.33, 0.80, and 4.2, respectively, at 170, 200, 240, and 280 degrees C. The van't Hoff plot results in the enthalpy change of DeltaH = 58 +/- 6 kJ mol(-1). The decarboxylation rate is also measured at 240-330 degrees C in both acidic and basic conditions. The rate is weakly dependent on the solution pH and is of the order of 10(-4) mol kg(-1) s(-1) at 330 degrees C. Furthermore, the equilibrium constant K(CO2) = [CO(2)][H(2)]/[HCOOH] is estimated to be 1.0 x10(2) mol kg(-1) at 330 degrees C. PMID:16986841

  6. Molten Salt Catalysts for Sulfuric Acid Production and SO2 Removal From Flue Gas

    Eriksen, Kim Michael; Fehrmann, Rasmus

    1996-01-01

    The report summarises the results obtained during 3 years of collaboration between ICE/HT,University of Patras,GR and Department of Chemistry,DTU,DK , supported by EU through a BRITE/EURAM project.The project has been concerned with fundamental investigations on the complex , redox and compound c...... chemistry of the V2O5 based sulfuric acid catalysts and model systems...

  7. Gas-phase studies of copper catalyzed aerobic cross coupling of thiol esters and arylboronic acids

    Tsybizová, A.; Schröder, Detlef; Roithová, J.; Henke, A.; Šrogl, Jiří

    2014-01-01

    Roč. 27, č. 3 (2014), s. 198-203. ISSN 0894-3230 R&D Projects: GA ČR GAP207/12/0846 Grant ostatní: GA ČR(CZ) GAP207/11/0338 Institutional support: RVO:61388963 Keywords : boronic acids * catalysis * copper * cross coupling * electrospray ionization * mass spectrometry * kinetic studies Subject RIV: CC - Organic Chemistry Impact factor: 1.380, year: 2014

  8. Characterization and solventless growth of salicylic acid macro-crystals involving a nitrogen gas flow

    Menaa, B. [Fluorotronics, Inc., San Diego Technology Incubator, 1425 Russ. Bvld, San Diego, CA 92121 (United States); Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); Takahashi, M. [Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); Department of Materials science, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Sakai, Osaka 599-8531 (Japan); Tokuda, Y.; Yoko, T. [Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan)

    2010-04-15

    We report an original solventless thermal crystallisation method to grow large needle-like salicylic acid (SA) crystals of 10-12 mm in length. The method is based on the utilization of nitrogen gaz flow on salicylic acid powder during heating just below melting point temperature for 24 h. Salicylic acid provides one of the best examples of a pharmaceutical substance used for cosmetics whose physical and chemical properties indicate hydrogen-bond formation between the hydroxyl group and an adjacent oxygen atom of the same molecule. The structure of the crystals is confirmed by single crystal X-ray diffraction; it is monoclinic, a = 4.93(2) Aa, b = 11.23(5) Aa, c = 11.56(6) Aa, {beta} = 90.77(4) with the space group P 2{sub 1}/c. The macrocrystals formation using this method is new and represents an interesting finding for a wide range of applications to be developed in the fields of biotechnology and photonics (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  9. Survey and Down-Selection of Acid Gas Removal Systems for the Thermochemical Conversion of Biomass to Ethanol with a Detailed Analysis of an MDEA System

    Nexant, Inc., San Francisco, California

    2011-05-01

    The first section (Task 1) of this report by Nexant includes a survey and screening of various acid gas removal processes in order to evaluate their capability to meet the specific design requirements for thermochemical ethanol synthesis in NREL's thermochemical ethanol design report (Phillips et al. 2007, NREL/TP-510-41168). MDEA and selexol were short-listed as the most promising acid-gas removal agents based on work described in Task 1. The second report section (Task 2) describes a detailed design of an MDEA (methyl diethanol amine) based acid gas removal system for removing CO2 and H2S from biomass-derived syngas. Only MDEA was chosen for detailed study because of the available resources.

  10. Optimization design of mixed amine method for removal of acid gas process%混合胺法脱酸工艺的优化设计

    王志祥

    2016-01-01

    利用混合胺法脱除天然气中的酸性气体,投资少、能耗低、CO2净化度高,脱除效果显著。%This paper,we propose use mixed amine method to remove acid gas from natural gas. This method has less investment,low energy consumption,high purification degree of CO2,and removal effect is remarkable.

  11. Combining NMR Spectroscopy and Gas-Liquid Chromatography for Analysis of the Fatty Acid Composition of Fenugreek Seed Oil (Trigonella foenum graecum L.)

    Skakovskii, E. D.; Tychinskaya, L. Yu.; Mauchanava, V. A.; Karankevich, E. G.; Lamotkin, S. A.; Ahabalayeva, A. D.; Reshetnikov, V. N.

    2013-11-01

    1H and 13C NMR spectroscopy established that fenugreek seed oil consists mainly of triacylglycerides. Oleic and linoleic acids are found preferentially in the 2 position and α-linolenic acid is found preferentially in the 1,3 positions of the glycerol backbone. By combining NMR and gas-liquid chromatography, we have shown that fenugreek seeds contain 5.5 %-6.8 % oil, consisting mainly of unsaturated fatty acids (68.2 %-82.1 %): linoleic (31.3 %-46.8 %), α-linolenic (15.1 %-36.6 %), and oleic (11.6 %-21.3 %). The highest unsaturated fatty acid content is found in the cultivars D-19, Ovary Gold, Blidet, Ovary 4 and the lowest fatty acid content is found in the Metha cultivar. The percentage of polyunsaturated fatty acids is higher in oils of fenugreek cultivars from northern regions (Belarus, Hungary, France).

  12. Characteristic chromatographic fingerprint study of short-chain fatty acids in human milk, infant formula, pure milk and fermented milk by gas chromatography-mass spectrometry.

    Jiang, Zhenzuo; Liu, Yanan; Zhu, Yan; Yang, Jing; Sun, Lili; Chai, Xin; Wang, Yuefei

    2016-09-01

    Human milk, infant formula, pure milk and fermented milk as food products or dietary supplements provide a range of nutrients required to both infants and adults. Recently, a growing body of evidence has revealed the beneficial roles of short-chain fatty acids (SCFAs), a subset of fatty acids produced from the fermentation of dietary fibers by gut microbiota. The objective of this study was to establish a chromatographic fingerprint technique to investigate SCFAs in human milk and dairy products by gas chromatography coupled with mass spectrometry. The multivariate method for principal component analysis assessed differences between milk types. Human milk, infant formula, pure milk and fermented milk were grouped independently, mainly because of differences in formic acid, acetic acid, propionic acid and hexanoic acid levels. This method will be important for the assessment of SCFAs in human milk and various dairy products. PMID:27282191

  13. Analysis of radioactive mixed hazardous wastes using derivatization gas chromatography/mass spectrometry(GC/MS) and liquid chromatography(LC)

    At the Hanford site in southeastern Washington, 24 of the 177 high-level waste tanks are being watched closely because of the possibility that flammable gas mixtures may be produced from the mixed wastes contained in the storage tanks. One tank in particular, Tank 241-SY-101 (Tank 101-SY), has exhibited episodic releases of flammable gas mixtures since its final filling in the late 1970s. It has been postulated that the organic compounds present in the waste may be precursors to the production of hydrogen. Six samples of core segments from Tank 101-SY, obtained during the window E core sampling, have been analyzed for organic constituents using derivatization gas chromatography/mass spectrometry (GC/MS), liquid chromatography (LC), and LC/MS. Four of the samples were from the upper region, or convective layer, of the tank and two were from the lower, nonconvective layer. The combined techniques of derivatization GC/MS and LC have accounted for approximately 71 to 93% of the total organic carbon depending on the sample. In addition, normal paraffin hydrocarbon (C12-C15) was detected in the convective layer samples

  14. Separation of cis/trans fatty acid isomers on gas chromatography compared to the Ag-TLC method

    Sundaresan, A.

    2013-03-01

    Full Text Available The present study investigates the separation of the cis/trans isomers of fatty acids on the 75 m SP2560 column under different gas chromatographic (GC conditions including an isothermal program and a time-temperature program. The time-temperature program showed improved separation of cis/trans isomers of C14:1, C16:1, C18:1, C18:2 and C18:3 fatty acids along with short chain fatty acids compared to the isothermal program. The separation of trans/trans isomers of C18:1 fatty acids including elaidic acid (C18:1 ∆9t and vaccenic acid (C18:1 ∆11t was difficult with the time-temperature program. The thin layer chromatography impregnated with silver nitrate (Ag- TLC method was performed to separate cis/trans fractions and GC analysis was carried out with the trans fraction. But GC analysis showed a co-elution of trans isomers of C18:1 fatty acid. Thus the study shows that a time-temperature programmed GC method with the highly polar cyanopropyl column is sufficient to resolve trans fatty acids along with short chain fatty acids when a large number of samples has to be analyzed.El presente estudio investiga la separación de isómeros cis/trans de ácidos grasos mediante cromatografía de gases (GC utilizando una columna de SP2560 de 75 m y diferentes condiciones que incluyen un programa isotérmico y una programación temperatura-tiempo. La programación temperatura- tiempo mostró una mejor separación de isómeros cis / trans de los ácidos grasos C14:1, C16:1, C18:1, C18:2 y C18:3 con los ácidos grasos de cadena corta en comparación con el programa isotermo. La separación de los isómeros trans/trans de los ácidos grasos C18:1 incluyendo ácido elaídico (C18:1 Δ9t y ácido vaccénico (C18:1Δ11t fué difícil mediante programación temperatura-tiempo. La cromatografía en capa fina impregnada con nitrato de plata (Ag-TLC se realizó para separar fracciones cis/trans y el análisis de la fracciones se llevó a cabo mediante GC. El an

  15. Disposable reversed-phase chromatography columns for improved detection of carboxylic acids in body fluids by electron-capture gas-liquid chromatography.

    Daneshvar, M. I.; Brooks, J B; Winstead, R M

    1987-01-01

    Disposable reversed-phase chromatography columns were tested for their effectiveness in removing unreacted trichloroethanol (TCE) from derivatized samples for gas-liquid chromatography analysis. Derivatized acidic chloroform extracts of saponified whole cells of Mycobacterium species, spent culture media, and derivatized acidic chloroform extracts of serum and cerebrospinal fluids from patients with tuberculous meningitis were tested. Samples were added to preconditioned reversed-phase chroma...

  16. Gas chromatographic measurement of 3- and 4-thia fatty acids incorporated into various classes of rat liver lipids during feeding experiments.

    Grav, H J; Asiedu, D K; Berge, R K

    1994-08-01

    A practical procedure is described for the quantitative measurement of the amount of acyl units derived from tetradecylthioacetic acid (effecting hypolipemia in rats) and tetradecylthiopropionic acid (effecting hyperlipidemia). The procedure involves three main successive steps: (1) extraction; (2) solid-phase lipid class separation yielding free fatty acids, phospholipids, triacylglycerides, cholesterol esters, and diacylglycerides without crosscontamination; and (3) gas chromatography of hydrolyzed lipids derivatized to picolinyl esters, combined with unambiguous identification by gas chromatography-mass spectrometry. The overall recoveries of heptadecanoyl lipids added as internal standards during extraction were 94-96%, except for cholesteryl heptadecanoate where the recovery was 60% owing to incomplete hydrolysis. Recoveries of thia fatty acids from samples spiked with these compounds were 95%. Flame-ionization response factors were found to be 0.92 and 0.81 for the tetradecylthioacetic acid and tetradecylthiopropionic acid picolinyl esters, respectively, compared to that of heptadecanoic acid. The lower limit of quantitation was 25 pmol as injected. Measurement of the amount of thia fatty acyl units in rat plasma and in liver lipids 4 h after administration of single doses by gastric intubation indicated efficient absorbtion and rapid incorporation into liver lipids, particularly in the phospholipid fraction. Both plasma clearance and channelling into lipids was slower for the 4-thia fatty acid. PMID:7952108

  17. Pepsin and bile acid concentrations in sputum of mustard gas exposed patients

    Ashraf Karbasi

    2013-01-01

    Full Text Available Background/Aim: Gastro-esophageal reflux has been suggested to be associated with several pulmonary complications such as asthma, and post-transplant bronchiolitis obliterans (BO. Pepsin or bile salts in the sputum is shown to be an optimal molecular marker of gastric contents macro/micro aspiration. In this study, we investigated sputum pepsin as a marker of micro-aspiration in sulfur mustard (SM exposed cases compared to healthy controls. Materials and Methods: In a case controlled study, 26 cases with BO and 12 matched healthy controls were recruited and all cases were symptomatic and their exposure to SM was previously documented during Iran-Iraq conflict. Pepsin levels in sputum and total bile acids were measured using enzymatic assay. The severity of respiratory disorder was categorized based upon the spirometric values. Result: The average concentration of pepsin in sputum was higher in the case group (0.29 ± 0.23 compared with healthy subjects (0.13 ± 0.07; P ± 0.003. Moreover, the average concentration of bile acids in the sputum cases was not significantly different in comparison to the controls ( P = 0.5. Conclusion: Higher pepsin concentrations in sputum of SM exposed patients compared with healthy control subjects indicate the occurrence of significantly more gastric micro-aspiration in SM exposed patients.

  18. A study about dimers formation of formic acid in gas phase and in the valence region

    Full text: Study of simple pre-biotic molecules takes great importance for understanding about complex organic molecules formation like amino acids, proteins and nucleobases within the DNA and RNA. A hypothesis for the appearance of nucleobases is that they could have been synthesized from simpler organic composites contained in interstellar medium (ISM), meteorites and asteroids. Lots of experiments have demonstrated that it is possible to produce complex pre-biotic molecules from simpler molecules under environments that simulate the ISM. Thus, we have performed a theoretical and experimental study about photoionization and photofragmentation processes of simple pre-biotic molecules that are important in the synthesis of complex biomolecules. In this work particularly, we performed photoionization and photofragmentation process of formic acid-D2 (CDOOD) in order to verify if some molecular fragmentations coming from dimers that could be formed before ionization region at TOF mass spectrometer. Experimentally, we measured these molecules mass spectra in gaseous phase. These spectra were got as function of pressures in experimental chamber, temperature samples and photon energy, in the vacuum ultraviolet region, between 11 and 20 eV. These data had been obtained in the Brazilian Laboratory of Synchrotron Light, by using mass spectrometer of flight time. The mass spectra had been obtained by using the photoelectron photoion coincidence technique, PEPICO. For a better understanding of experimental results, we have made a theoretical analysis of the photofragmentation by using Density Functional Theory. (author)

  19. A mass spectrometric study of the acid-catalysed d-fructose dehydration in the gas phase.

    Pepi, Federico; Ricci, Andreina; Garzoli, Stefania; Troiani, Anna; Salvitti, Chiara; Di Rienzo, Brunella; Giacomello, Pierluigi

    2015-09-01

    5-hydroxymethylfuraldehyde (5-HMF) and simpler compounds, such as levulinic acid (LA) and glyceraldehyde, are platform molecules produced by the thermal acid-catalyzed dehydration of carbohydrates coming from biomass. Understanding sugar degradation pathways on a molecular level is necessary to increase selectivity, reduce degradation by-products yields and optimize catalytic strategies, fundamental knowledge for the development of a sustainable renewable industry. In this work gaseous protonated d-fructose ions, generated in the ESI source of a triple quadrupole mass spectrometer, were allowed to undergo Collisionally Activated Decomposition (CAD) into the quadrupole collision cell. The ionic intermediates and products derived from protonated d-fructose dehydration were structurally characterized by their fragmentation patterns and the relative water-loss dehydration energies measured by energy-resolved CAD mass spectra. The data were compared with those obtained from protonated d-glucose decomposition in the same experimental conditions. In the gas phase, d-fructose dehydration leads to the formation of a mixed population of isomeric [C6H6O3]H(+) ions, whose structures do not correspond exclusively to 5-hydroxymethyl-2-furaldehyde protonated at the more basic aldehydic group. PMID:26122965

  20. An energy-efficient process for decomposing perfluorooctanoic and perfluorooctane sulfonic acids using dc plasmas generated within gas bubbles

    Yasuoka, K; Sasaki, K; Hayashi, R, E-mail: yasuoka@ee.titech.ac.jp [Department of Electrical and Electronic Engineering, Tokyo Institute of Technology, Ookayama, Tokyo (Japan)

    2011-06-15

    Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) are environmentally harmful and persistent substances. Their decomposition was investigated using dc plasmas generated within small gas bubbles in a solution. The plasma characteristics including discharge voltage, voltage drop in the liquid, plasma shape and the emission spectrum were examined with different gases. The decomposition rate and energy efficiency were evaluated by measuring the concentration of fluoride and sulfate ions released from PFOA/PFOS molecules. The concentration of fluoride ions and energy efficiency in the treatment of a PFOS solution were 17.7 mg l{sup -1} (54.8% of the initial amount of fluorine atoms) and 26 mg kWh{sup -1}, respectively, after 240 min of operation. The addition of scavengers of hydroxyl radicals and hydrated electrons showed little effect on the decomposition. The decomposition processes were analyzed with an assumption that positive species reacted with PFOA/PFOS molecules at the boundary of the plasma-solution surface. This type of plasma showed a much higher decomposition energy efficiency compared with energy efficiencies reported in other studies.

  1. An energy-efficient process for decomposing perfluorooctanoic and perfluorooctane sulfonic acids using dc plasmas generated within gas bubbles

    Yasuoka, K.; Sasaki, K.; Hayashi, R.

    2011-06-01

    Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) are environmentally harmful and persistent substances. Their decomposition was investigated using dc plasmas generated within small gas bubbles in a solution. The plasma characteristics including discharge voltage, voltage drop in the liquid, plasma shape and the emission spectrum were examined with different gases. The decomposition rate and energy efficiency were evaluated by measuring the concentration of fluoride and sulfate ions released from PFOA/PFOS molecules. The concentration of fluoride ions and energy efficiency in the treatment of a PFOS solution were 17.7 mg l-1 (54.8% of the initial amount of fluorine atoms) and 26 mg kWh-1, respectively, after 240 min of operation. The addition of scavengers of hydroxyl radicals and hydrated electrons showed little effect on the decomposition. The decomposition processes were analyzed with an assumption that positive species reacted with PFOA/PFOS molecules at the boundary of the plasma-solution surface. This type of plasma showed a much higher decomposition energy efficiency compared with energy efficiencies reported in other studies.

  2. An energy-efficient process for decomposing perfluorooctanoic and perfluorooctane sulfonic acids using dc plasmas generated within gas bubbles

    Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) are environmentally harmful and persistent substances. Their decomposition was investigated using dc plasmas generated within small gas bubbles in a solution. The plasma characteristics including discharge voltage, voltage drop in the liquid, plasma shape and the emission spectrum were examined with different gases. The decomposition rate and energy efficiency were evaluated by measuring the concentration of fluoride and sulfate ions released from PFOA/PFOS molecules. The concentration of fluoride ions and energy efficiency in the treatment of a PFOS solution were 17.7 mg l-1 (54.8% of the initial amount of fluorine atoms) and 26 mg kWh-1, respectively, after 240 min of operation. The addition of scavengers of hydroxyl radicals and hydrated electrons showed little effect on the decomposition. The decomposition processes were analyzed with an assumption that positive species reacted with PFOA/PFOS molecules at the boundary of the plasma-solution surface. This type of plasma showed a much higher decomposition energy efficiency compared with energy efficiencies reported in other studies.

  3. Effect of Al content on the gas-phase dehydration of glycerol over silica-alumina-supported silicotungstic acid catalysts

    The gas-phase dehydration of glycerol to acrolein was carried out over silicotungstic acid (H4SiW12O40·xH2O, HSiW) catalysts supported on SiO2, η-Al2O3, and silica-alumina with different Al contents. The HSiW catalysts supported on silica-alumina showed higher glycerol conversions and acrolein yields during the initial 2 h at 315.deg.C than did SiO2- and η-Al2O3-supported HSiW catalysts. Among the tested catalysts, HSiW/Si0.9Al0.1Ox exhibited the highest space-time yield during the initial 2 h. The loaded HSiW species can change the acid types and suppress the formation of carbonaceous species on Al-rich silica-alumina. The deactivated HSiW supported on silica-alumina can be fully regenerated after calcination in air at 500.deg.C. As long as the molar ratio between water and glycerol was in the range of 2-11, the acrolein selectivity increased significantly with increasing water content in the feed, while the surface carbon content decreased owing to the suppression of heavy compounds

  4. Effect of Al content on the gas-phase dehydration of glycerol over silica-alumina-supported silicotungstic acid catalysts

    Kim, Yong Tae; You, Su Jin; Park, Eun Duck [Ajou Univ., Suwon (Korea, Republic of); Jung, Kwangdeog [Korea Institute of Science and Technology, Seoul (Korea, Republic of)

    2012-07-15

    The gas-phase dehydration of glycerol to acrolein was carried out over silicotungstic acid (H{sub 4}SiW{sub 12}O{sub 40}{center_dot}xH{sub 2}O, HSiW) catalysts supported on SiO{sub 2}, {eta}-Al{sub 2}O{sub 3}, and silica-alumina with different Al contents. The HSiW catalysts supported on silica-alumina showed higher glycerol conversions and acrolein yields during the initial 2 h at 315.deg.C than did SiO{sub 2}- and {eta}-Al{sub 2}O{sub 3}-supported HSiW catalysts. Among the tested catalysts, HSiW/Si{sub 0.9}Al{sub 0.1Ox} exhibited the highest space-time yield during the initial 2 h. The loaded HSiW species can change the acid types and suppress the formation of carbonaceous species on Al-rich silica-alumina. The deactivated HSiW supported on silica-alumina can be fully regenerated after calcination in air at 500.deg.C. As long as the molar ratio between water and glycerol was in the range of 2-11, the acrolein selectivity increased significantly with increasing water content in the feed, while the surface carbon content decreased owing to the suppression of heavy compounds.

  5. Life-cycle greenhouse gas emissions and energy balances of a biodiesel production from palm fatty acid distillate (PFAD)

    Highlights: • The LCA study of biodiesel production from palm fatty acid distillate was performed. • The reduction ratio of GHG emissions to fossil diesel is found to amount to 86.5%. • The net energy ratio is found to be 3.23. - Abstract: Life-cycle greenhouse gas (GHG) emissions and net energy ratio (NER) have been evaluated for the production of palm biodiesel from palm fatty acid distillate (PFAD) which is a by-product in the refining process. For the case that PFAD is regarded as a processing residue, GHG emissions associated with biodiesel production in the considered process is 86.5% less than that of fossil diesel, which surpasses even the threshold of year 2018 of the Renewable Energy Directive (RED) of the European Union (EU). In the present study, it is also shown that the value of the NER is 3.23, which means that the energy yield from palm methyl ester (PME) production from PFAD is around three times larger than the input of fossil energy in the production. In conclusion, the palm biodiesel from PFAD can be one of various alternatives to the ‘conventional’ palm biodiesel which is made of refined palm oil, and sustainability issues and ethical problems can be considerably minimized with the strategic utilization of palm biodiesel produced from PFAD

  6. 气相色谱法分析炸鸡油中脂肪酸及反式脂肪酸%Gas Chromatography Analysis on Fatty Acids and Trans fatty Acids in Fried Chicken Oil

    王建清; 张玉; 陶秋

    2011-01-01

    Fatty acid and trans fatty acids from the kentucky fried chicken raw and cooked oils were analysed qualitativly and quantitativly by capillary gas chromatography. The results showed that kentucky fried chicken used palm oil, fatty acid components were palmitic acid, stearie acid, oleic acid, linoleic acid, containing about l percent of C 18:2 and C 18:3 trans fatty acids, trans-fatty acids content in mature oil were more than that in raw oil, which showed that frying process would produce small amounts of trans fatty acids.%应用毛细管气相色谱法对源自肯德基的生熟炸鸡油进行了脂肪酸及反式脂肪酸定性、定量分析,结果表明:肯德基炸鸡油选用棕榈油,脂肪酸组分主要有棕榈酸、硬脂酸、油酸、亚油酸,且含有反式亚油酸、亚麻酸约1%,熟油则比生油含更多的反式脂肪酸,表明煎炸过程中会产生少量反式脂肪酸。

  7. 天然气管道泄漏后硫化氢和甲烷危险区域分析%Analysis on Hydrogen Sulfide and Methane Gas Hazardous Area After Pipeline Leak

    王龙; 马贵阳

    2015-01-01

    天然气管道泄漏扩散是天然气工业中最为常见的事故,根据不同的工况来准确的预测泄漏后的危险区域是事故处理中最为重要的预测项目之一。根据单一变量原则在考虑埋深的前提下对平坦地区和山谷地区埋地天然气管道泄漏进行三维数值模拟,针对两种工况泄漏后硫化氢和甲烷的危险区域进行分析。结果表明:无论是平坦地区还是山谷地区低速泄漏时对比两种气体危险区域的三维柱状图,可以看出硫化氢的危险区域总是比甲烷的大很多且完全覆盖甲烷的危险区域。建议事故处理以硫化氢的危险区域为主要预测项目。%Gas pipeline leakage and diffusion are the most common gas industry accidents. To accurately predict the danger zone after the leak based on different conditions is one of the most important prediction projects. In this paper, based on the principle of a single variable, under the premise of considering the depth, three-dimensional numerical simulation of buried natural gas pipeline leak in flat areas and valleys was carried out to analyze the dangerous zone of hydrogen sulfide and methane. The results show that, for either flat regions or valleys, comparing hazardous area three-dimensional bar graphs of the two gases when low-leakage, the dangerous zone of hydrogen sulfide is always much larger than that of methane, so hazardous area of hydrogen sulfide in accident treatment should be recommended as the primary item of project.

  8. Eddy covariance captures four-phase crassulacean acid metabolism (CAM) gas exchange signature in Agave.

    Owen, Nick A; Choncubhair, Órlaith Ní; Males, Jamie; Del Real Laborde, José Ignacio; Rubio-Cortés, Ramón; Griffiths, Howard; Lanigan, Gary

    2016-02-01

    Mass and energy fluxes were measured over a field of Agave tequilana in Mexico using eddy covariance (EC) methodology. Data were gathered over 252 d, including the transition from wet to dry periods. Net ecosystem exchanges (FN,EC ) displayed a crassulacean acid metabolism (CAM) rhythm that alternated from CO2 sink at night to CO2 source during the day, and partitioned canopy fluxes (FA,EC ) showed a characteristic four-phase CO2 exchange pattern. Results were cross-validated against diel changes in titratable acidity, leaf-unfurling rates, energy exchange fluxes and reported biomass yields. Projected carbon balance (g C m(-2)  year(-1) , mean ± 95% confidence interval) indicated the site was a net sink of -333 ± 24, of which contributions from soil respiration were +692 ± 7, and FA,EC was -1025 ± 25. EC estimated biomass yield was 20.1 Mg (dry) ha(-1)  year(-1) . Average integrated daily FA,EC was -234 ± 5 mmol CO2  m(-2)  d(-1) and persisted almost unchanged after 70 d of drought conditions. Regression analyses were performed on the EC data to identify the best environmental predictors of FA . Results suggest that the carbon acquisition strategy of Agave offers productivity and drought resilience advantages over conventional semi-arid C3 and C4 bioenergy candidates. PMID:26177873

  9. Liquid–liquid extraction of Cd(II) from pure and Ni/Cd acidic chloride media using Cyanex 921: A selective treatment of hazardous leachate of spent Ni–Cd batteries

    Choi, Seon-Young [Chungnam National University (CNU), Environmental Engineering, Daejeon 305-764 (Korea, Republic of); Korea Institute of Geoscience and Mineral Resources (KIGAM), Mineral Resources Research Division, Daejeon 305-350 (Korea, Republic of); Nguyen, Viet Tu, E-mail: writtingtu@gmail.com [Korea Institute of Geoscience and Mineral Resources (KIGAM), Mineral Resources Research Division, Daejeon 305-350 (Korea, Republic of); Korea University of Science and Technology (UST), Resources Recycling, Daejeon 305-350 (Korea, Republic of); Lee, Jae-chun, E-mail: jclee@kigam.re.kr [Korea Institute of Geoscience and Mineral Resources (KIGAM), Mineral Resources Research Division, Daejeon 305-350 (Korea, Republic of); Korea University of Science and Technology (UST), Resources Recycling, Daejeon 305-350 (Korea, Republic of); Kang, Ho [Chungnam National University (CNU), Environmental Engineering, Daejeon 305-764 (Korea, Republic of); Pandey, B.D. [CSIR – National Metallurgical Laboratory (NML), Metal Extraction and Forming Division, Jamshedpur 831007 (India)

    2014-08-15

    Highlights: • Cd(II) extraction from acidic chloride waste solutions using Cyanex 921 is optimized. • Chemistry of Cd(II) in HCl solutions is first-ever considered for the extraction mechanism. • Cd(II) species is extracted in Cyanex 921 (L) as a neutral complex HCdCl{sub 3}·4L. • Calculated thermodynamic parameters give an insight into Cd(II) complexation reactions. • Cyanex 921 can be used for the selective treatment of hazardous waste Ni–Cd batteries. - Abstract: The present paper is focused on solvent extraction of hazardous Cd(II) from acidic chloride media by Cyanex 921, a new extractant mixed with 10% (v/v) TBP in xylene. The optimum conditions for extraction and stripping of Cd(II) were investigated with an aqueous feed of 0.1 mol/L Cd(II) in 2.0 mol/L HCl. McCabe–Thiele diagram was in good agreement with the simulation studies, showing the quantitative extraction (99.9%) of Cd(II) within two counter-current stages utilizing 0.30 mol/L Cyanex 921 at O/A ratio of 3/2 in 10 min. Stoichiometry of the complexes extracted was determined and confirmed by numerical treatment and graphical method, revealing the formation of HCdCl{sub 3}·2L and HCdCl{sub 3}·4L for Cyanex 921(L) concentration in the range 0.03–0.1 mol/L and 0.1–1.0 mol/L, respectively. The thermodynamic parameters for the extraction of cadmium were also determined. The stripping efficiency of cadmium from the loaded organic with 0.10 mol/L HCl was 99.6% in a three-stage counter-current process at an O/A ratio of 2/3. Cyanex 921 was successfully applied for the separation of Cd(II) from Ni(II) in the simulated leach liquor of spent Ni–Cd batteries. The study demonstrates the applicability of the present hydrometallurgical approach for the treatment of hazardous waste, the spent Ni–Cd batteries.

  10. Liquid–liquid extraction of Cd(II) from pure and Ni/Cd acidic chloride media using Cyanex 921: A selective treatment of hazardous leachate of spent Ni–Cd batteries

    Highlights: • Cd(II) extraction from acidic chloride waste solutions using Cyanex 921 is optimized. • Chemistry of Cd(II) in HCl solutions is first-ever considered for the extraction mechanism. • Cd(II) species is extracted in Cyanex 921 (L) as a neutral complex HCdCl3·4L. • Calculated thermodynamic parameters give an insight into Cd(II) complexation reactions. • Cyanex 921 can be used for the selective treatment of hazardous waste Ni–Cd batteries. - Abstract: The present paper is focused on solvent extraction of hazardous Cd(II) from acidic chloride media by Cyanex 921, a new extractant mixed with 10% (v/v) TBP in xylene. The optimum conditions for extraction and stripping of Cd(II) were investigated with an aqueous feed of 0.1 mol/L Cd(II) in 2.0 mol/L HCl. McCabe–Thiele diagram was in good agreement with the simulation studies, showing the quantitative extraction (99.9%) of Cd(II) within two counter-current stages utilizing 0.30 mol/L Cyanex 921 at O/A ratio of 3/2 in 10 min. Stoichiometry of the complexes extracted was determined and confirmed by numerical treatment and graphical method, revealing the formation of HCdCl3·2L and HCdCl3·4L for Cyanex 921(L) concentration in the range 0.03–0.1 mol/L and 0.1–1.0 mol/L, respectively. The thermodynamic parameters for the extraction of cadmium were also determined. The stripping efficiency of cadmium from the loaded organic with 0.10 mol/L HCl was 99.6% in a three-stage counter-current process at an O/A ratio of 2/3. Cyanex 921 was successfully applied for the separation of Cd(II) from Ni(II) in the simulated leach liquor of spent Ni–Cd batteries. The study demonstrates the applicability of the present hydrometallurgical approach for the treatment of hazardous waste, the spent Ni–Cd batteries

  11. The tropospheric processing of acidic gases and hydrogen sulphide in volcanic gas plumes as inferred from field and model investigations

    A. Aiuppa

    2006-11-01

    Full Text Available Improving the constraints on the atmospheric fate and depletion rates of acidic compounds persistently emitted by non-erupting (quiescent volcanoes is important for quantitatively predicting the environmental impact of volcanic gas plumes. Here, we present new experimental data coupled with modelling studies to investigate the chemical processing of acidic volcanogenic species during tropospheric dispersion. Diffusive tube samplers were deployed at Mount Etna, a very active open-conduit basaltic volcano in eastern Sicily, and Vulcano Island, a closed-conduit quiescent volcano in the Aeolian Islands (northern Sicily. Sulphur dioxide (SO2, hydrogen sulphide (H2S, hydrogen chloride (HCl and hydrogen fluoride (HF concentrations in the volcanic plumes (typically several minutes to a few hours old were repeatedly determined at distances from the summit vents ranging from 0.1 to ~10 km, and under different environmental conditions. At both volcanoes, acidic gas concentrations were found to decrease exponentially with distance from the summit vents (e.g., SO2 decreases from ~10 000 μg/m3 at 0.1 km from Etna's vents down to ~7 μg/m3 at ~10 km distance, reflecting the atmospheric dilution of the plume within the acid gas-free background troposphere. Conversely, SO2/HCl, SO2/HF, and SO2/H2S ratios in the plume showed no systematic changes with plume aging, and fit source compositions within analytical error. Assuming that SO2 losses by reaction are small during short-range atmospheric transport within quiescent (ash-free volcanic plumes, our observations suggest that, for these short transport distances, atmospheric reactions for H2S and halogens are also negligible. The one-dimensional model MISTRA was used to simulate quantitatively the evolution of halogen and sulphur compounds in the plume of Mt. Etna. Model predictions

  12. The tropospheric processing of acidic gases and hydrogen sulphide in volcanic gas plumes as inferred from field and model investigations

    A. Aiuppa

    2007-01-01

    Full Text Available Improving the constraints on the atmospheric fate and depletion rates of acidic compounds persistently emitted by non-erupting (quiescent volcanoes is important for quantitatively predicting the environmental impact of volcanic gas plumes. Here, we present new experimental data coupled with modelling studies to investigate the chemical processing of acidic volcanogenic species during tropospheric dispersion. Diffusive tube samplers were deployed at Mount Etna, a very active open-conduit basaltic volcano in eastern Sicily, and Vulcano Island, a closed-conduit quiescent volcano in the Aeolian Islands (northern Sicily. Sulphur dioxide (SO2, hydrogen sulphide (H2S, hydrogen chloride (HCl and hydrogen fluoride (HF concentrations in the volcanic plumes (typically several minutes to a few hours old were repeatedly determined at distances from the summit vents ranging from 0.1 to ~10 km, and under different environmental conditions. At both volcanoes, acidic gas concentrations were found to decrease exponentially with distance from the summit vents (e.g., SO2 decreases from ~10 000 μg/m3at 0.1 km from Etna's vents down to ~7 μg/m3 at ~10 km distance, reflecting the atmospheric dilution of the plume within the acid gas-free background troposphere. Conversely, SO2/HCl, SO2/HF, and SO2/H2S ratios in the plume showed no systematic changes with plume aging, and fit source compositions within analytical error. Assuming that SO2 losses by reaction are small during short-range atmospheric transport within quiescent (ash-free volcanic plumes, our observations suggest that, for these short transport distances, atmospheric reactions for H2S and halogens are also negligible. The one-dimensional model MISTRA was used to simulate quantitatively the evolution of halogen and sulphur compounds in the plume of Mt. Etna. Model predictions support the hypothesis of minor HCl chemical processing during plume transport, at least in cloud-free conditions. Larger

  13. Potential hazards of air pollutant emissions from unconventional oil and natural gas operations on the respiratory health of children and infants.

    Webb, Ellen; Hays, Jake; Dyrszka, Larysa; Rodriguez, Brian; Cox, Caroline; Huffling, Katie; Bushkin-Bedient, Sheila

    2016-06-01

    Research on air pollutant emissions associated with unconventional oil and gas (UOG) development has grown significantly in recent years. Empirical investigations have focused on the identification and measurement of oil and gas air pollutants [e.g. volatile organic compounds (VOCs), particulate matter (PM), methane] and the influence of UOG on local and regional ambient air quality (e.g. tropospheric ozone). While more studies to better characterize spatial and temporal trends in exposure among children and newborns near UOG sites are needed, existing research suggests that exposure to air pollutants emitted during lifecycle operations can potentially lead to adverse respiratory outcomes in this population. Children are known to be at a greater risk from exposure to air pollutants, which can impair lung function and neurodevelopment, or exacerbate existing conditions, such as asthma, because the respiratory system is particularly vulnerable during development in-utero, the postnatal period, and early childhood. In this article, we review the literature relevant to respiratory risks of UOG on infants and children. Existing epidemiology studies document the impact of air pollutant exposure on children in other contexts and suggest impacts near UOG. Research is sparse on long-term health risks associated with frequent acute exposures - especially in children - hence our interpretation of these findings may be conservative. Many data gaps remain, but existing data support precautionary measures to protect the health of infants and children. PMID:27171386

  14. OPTIMIZING TECHNOLOGY TO REDUCE MERCURY AND ACID GAS EMISSIONS FROM ELECTRIC POWER PLANTS

    Jeffrey C. Quick; David E. Tabet; Sharon Wakefield; Roger L. Bon

    2005-10-01

    Maps showing potential mercury, sulfur, chlorine, and moisture emissions for U.S. coal by county of origin were made from publicly available data (plates 1, 2, 3, and 4). Published equations that predict mercury capture by emission control technologies used at U.S. coal-fired utilities were applied to average coal quality values for 169 U.S. counties. The results were used to create five maps that show the influence of coal origin on mercury emissions from utility units with: (1) hot-side electrostatic precipitator (hESP), (2) cold-side electrostatic precipitator (cESP), (3) hot-side electrostatic precipitator with wet flue gas desulfurization (hESP/FGD), (4) cold-side electrostatic precipitator with wet flue gas desulfurization (cESP/FGD), and (5) spray-dry adsorption with fabric filter (SDA/FF) emission controls (plates 5, 6, 7, 8, and 9). Net (lower) coal heating values were calculated from measured coal Btu values, and estimated coal moisture and hydrogen values; the net heating values were used to derive mercury emission rates on an electric output basis (plate 10). Results indicate that selection of low-mercury coal is a good mercury control option for plants having hESP, cESP, or hESP/FGD emission controls. Chlorine content is more important for plants having cESP/FGD or SDA/FF controls; optimum mercury capture is indicated where chlorine is between 500 and 1000 ppm. Selection of low-sulfur coal should improve mercury capture where carbon in fly ash is used to reduce mercury emissions. Comparison of in-ground coal quality with the quality of commercially mined coal indicates that existing coal mining and coal washing practice results in a 25% reduction of mercury in U.S. coal before it is delivered to the power plant. Further pre-combustion mercury reductions may be possible, especially for coal from Texas, Ohio, parts of Pennsylvania and much of the western U.S.

  15. Synthesis of hydrophobic cross-linked polyzwitterionic acid for simultaneous sorption of Eriochrome black T and chromium ions from binary hazardous waters.

    Saleh, Tawfik A; Muhammad, Auwal M; Ali, Shaikh A

    2016-04-15

    Hydrophobic cross-linked polyzwitterionic acid (HCPZA) containing long chain (C18) hydrophobes and residues of a glutamic acid having unquenched nitrogen valency was synthesized. Exploiting the chelating ability of the amino acid residues to scavenge toxic metals and the hydrophobic surface to scoop up the organic contaminants, the resin HCPZA was evaluated for simultaneous removal of chromium and Eriochrome black T (EBT) from wastewaters. The structure and morphology of the polymer before and after sorption were characterized by using FTIR, TGA, EDX and SEM. The effect of various parameters such as contact time, pH and initial concentrations were investigated to arrive at optimum conditions. The adsorption of Eriochrome black T and Cr (III) on HCPZA reached equilibrium in 30 min. The mechanism of adsorption was investigated using kinetic, diffusion and isotherm models. The adsorption kinetic data were described well by the pseudo-second order model and by the Freundlich isotherm model. EDX analysis confirmed the adsorption of Cr (III) and EBT on the polymer. The hydrophobic resin exhibited a remarkable simultaneous adsorption capacity for EBT and Cr (III) and thus demonstrated its potential to be a promising adsorbent for removal of dyes and heavy metal ions from wastewaters. PMID:26854746

  16. POPs as hazardous waste and appearance in the industry

    Alili, Agron; Karakaseva, Snezana; Krstev, Boris; Krstev, Aleksandar

    2014-01-01

    Hazardous waste is waste, which is consist from composition or concentration of hazardous substances which can cause hazards on environmental and people health and have one or more hazardous properties, such as explosive, reactive (oxidizing), flammability, irritability, toxicity, infectivity, carcinogenicity, mutagenicity, reproduction toxicity, ecotoxicity and discharge properties of toxic gases in contact with water, air od acid, determined in accordance with this law or other regulatin, w...

  17. DETECTION OF A MICROBIAL CONSORTIUM, INCLUDING TYPE 2 METHANOTROPHS, BY USE OF PHOSPHOLIPID FATTY ACIDES IN AN AEROBIC HALOGENATED HYDROCARBON-DEGRADING SOIL COLUMN ENRICHED WITH NATURAL GAS

    The phospholipid ester-linked normal and lipopolysaccharide layer hydroxy fatty acids from microbes in a natural gas (85% methane)-stimulated soil column capable of degrading halogenated hydrocarbons were analyzed in detail by capillary column GC-MS. Microbial biomass, calculated...

  18. Derivatisation/solid-phase microextraction followed by gas chromatography-mass spectrometry for the analysis of phenoxy acid herbicides in aqueous samples

    Nilsson, Torben; Baglio, Daniela; Galdo-Miguez, Isabel;

    1998-01-01

    Different combinations of derivatisation and solid-phase microextraction followed by gas chromatography-mass spectrometry were optimised and evaluated for the analysis of phenoxy acid herbicides in water. The most successful derivatisation approach was aqueous-phase derivatisation with benzyl...

  19. Lipid fatty acid profile analyses in liver and serum in rats with nonalcoholic steatohepatitis using improved gas chromatography-mass spectrometry methodology

    Fatty acids (FA) are essential components of lipids and exhibit important biological functions. The analyses of FAs are routinely carried out by gas chromatography-mass spectrometry, after multi-step sample preparation. In this study, several key experimental factors were carefully examined, validat...

  20. Involvement of placental/umbilical cord blood acid-base status and gas values on the radiosensitivity of human fetal/neonatal hematopoietic stem/progenitor cells

    Arterial cord blood (CB) acid-base status and gas values, such as pH, PCO2, PO2, HCO3- and base excess, provide useful information on the fetal and neonatal condition. However, it remains unknown whether these values affect the radiosensitivity of fetal/neonatal hematopoiesis. The present study evaluated the relationship between arterial CB acid-base status, gas values, and the radiosensitivity of CB hematopoietic stem/progenitor cells (HSPCs). A total of 25 CB units were collected. The arterial CB acid-base status and gas values were measured within 30 min of delivery. The CD34+ HSPCs obtained from CB were exposed to 2 Gy X-irradiation, and then assayed for colony-forming unit-granulocyte-macrophage, burst-forming unit-erythroid (BFU-E), and colony-forming unit-granulocyte erythroid, macrophage and megakaryocyte cells. Acid-base status and gas values for PCO2 and HCO3- showed a statistically significant negative correlation with the surviving fraction of BFU-E. In addition, a significant positive correlation was observed between gestational age and PCO2. Moreover, the surviving fraction of BFU-E showed a significant negative correlation with gestational age. Thus, HSPCs obtained from CB with high PCO2/HCO3- levels were sensitive to X-irradiation, which suggests that the status of arterial PCO2/HCO3- influences the radiosensitivity of fetal/neonatal hematopoiesis, especially erythropoiesis. (author)

  1. High-resolution gas chromatography/mas spectrometry method for characterization and quantitative analysis of ginkgolic acids in ginkgo biloba plants, extracts, and dietary supplements

    A high resolution GC/MS with Selected Ion Monitor (SIM) method focusing on the characterization and quantitative analysis of ginkgolic acids (GAs) in Ginkgo biloba L. plant materials, extracts and commercial products was developed and validated. The method involved sample extraction with (1:1) meth...

  2. Semi-continuous measurements of gas/particle partitioning of organic acids in a ponderosa pine forest using a MOVI-HRToF-CIMS

    R. L. N. Yatavelli

    2013-06-01

    Full Text Available Hundreds of gas and particle phase organic acids were measured in a rural ponderosa pine forest in Colorado, USA, during the Bio-hydro-atmosphere interactions of Energy, Aerosols, Carbon, H2O, Organics and Nitrogen – Rocky Mountain Biogenic Aerosol Study (BEACHON-RoMBAS. A recently developed Micro-Orifice Volatilization Impactor High-Resolution Time-of-Flight Chemical Ionization Mass Spectrometer (MOVI-HRToF-CIMS using acetate (CH3C(OO- as the reagent ion was used to selectively ionize and detect acids semi-continuously from 20–30 August 2011, with a measurement time resolution of ~1.5 h. At this site 98% of the organic acid mass is estimated to be in the gas-phase, with only ~2% in the particle phase. We investigated gas/particle partitioning, quantified as the fraction in the particle phase (Fp, of C1–C18 alkanoic acids, six known terpenoic acids and total bulk organic acids. Data were compared to the absorptive partitioning model and suggest that bulk organic acids at this site follow absorptive partitioning to the organic aerosol mass. The rapid response (<1–2 h of partitioning to temperature changes for bulk acids suggests that kinetic limitations to equilibrium are minor, which is in contrast to conclusions of some recent laboratory and field studies, possibly due to lack of very low ambient relative humidities at this site. Time trends for partitioning of individual and groups of acids were mostly captured by the model, with varying degrees of absolute agreement. Species with predicted substantial fractions in both the gas and particle phases show better absolute agreement, while species with very low predicted fractions in one phase often show agreement on trends, but poor absolute agreement, potentially due to thermal decomposition, inlet adsorption, or other issues. Based on measurement-model comparison we conclude that species carbon number and oxygen content, together with ambient temperature control the volatility of organic

  3. Hazard function theory for nonstationary natural hazards

    Read, L. K.; R. M. Vogel

    2015-01-01

    Impact from natural hazards is a shared global problem that causes tremendous loss of life and property, economic cost, and damage to the environment. Increasingly, many natural processes show evidence of nonstationary behavior including wind speeds, landslides, wildfires, precipitation, streamflow, sea levels, and earthquakes. Traditional probabilistic analysis of natural hazards based on peaks over threshold (POT) generally assumes stationarity in the magn...

  4. Field test of four methods for gas-phase ambient nitric acid

    Arnold, J. R.; Hartsell, Benjamin E.; Luke, Winston T.; Rahmat Ullah, S. M.; Dasgupta, Purnendu K.; Greg Huey, L.; Tate, Paul

    Three semi-continuous methods for detecting nitric acid (HNO 3) were tested against the annular denuder + filter pack (ADS) integrated collection technique at the Tampa Bay Regional Atmospheric Chemistry Experiment (BRACE) Sydney research station ˜20km downwind of the Tampa, Florida, urban core. The semi-continuous instruments included: two slightly differing implementations of the NOY-NO (total oxides of nitrogen minus that total denuded of HNO 3) denuder difference technique, one from the NOAA Air Resources Lab (ARL), and one from Atmospheric Research and Analysis, Inc. (ARA); the parallel plate wet diffusion scrubber + online ion chromatography technique from Texas Tech University (TTU); and the chemical ionization mass spectrometer from the Georgia Institute of Technology (GIT). Twelve hour ADS samples were collected by the University of South Florida (USF). Results for 10 min samples computed from the various higher sampling frequencies of each semi-continuous instrument showed good agreement (R2>0.7) for afternoon periods of the highest production and accumulation of HNO 3. Further, agreement was within ±30% for these instruments even at HNO 3 concentrations 60% for the nighttime samples; ADS results were below the corporate mean maximum HNO 3 concentration by >30% as well. The four instruments using semi-continuous methods, by contrast, were all within 10% of each other's 12 h mean mixing ratios. While only ARA employed a formal minimum detection limit at 0.050 ppb, error analysis with the other techniques established that at the same level of precision, TTU's effective limit was approximately the same as ARA's and that ARL's limit was 0.030 ppb; analysis for GIT showed no apparent effective limit at the levels of HNO 3 encountered in this field study. The importance of sample inlet height for HNO 3 measurements was indirectly shown through comparison to previous field work at this site when sample inlet heights ranged from 1.5-10 m and produced systematic

  5. The Contribution of the Activation Entropy to the Gas-Phase Stability of Modified Nucleic Acid Duplexes

    Hari, Yvonne; Dugovič, Branislav; Istrate, Alena; Fignolé, Annabel; Leumann, Christian J.; Schürch, Stefan

    2016-07-01

    Tricyclo-DNA (tcDNA) is a sugar-modified analogue of DNA currently tested for the treatment of Duchenne muscular dystrophy in an antisense approach. Tandem mass spectrometry plays a key role in modern medical diagnostics and has become a widespread technique for the structure elucidation and quantification of antisense oligonucleotides. Herein, mechanistic aspects of the fragmentation of tcDNA are discussed, which lay the basis for reliable sequencing and quantification of the antisense oligonucleotide. Excellent selectivity of tcDNA for complementary RNA is demonstrated in direct competition experiments. Moreover, the kinetic stability and fragmentation pattern of matched and mismatched tcDNA heteroduplexes were investigated and compared with non-modified DNA and RNA duplexes. Although the separation of the constituting strands is the entropy-favored fragmentation pathway of all nucleic acid duplexes, it was found to be only a minor pathway of tcDNA duplexes. The modified hybrid duplexes preferentially undergo neutral base loss and backbone cleavage. This difference is due to the low activation entropy for the strand dissociation of modified duplexes that arises from the conformational constraint of the tc-sugar-moiety. The low activation entropy results in a relatively high free activation enthalpy for the dissociation comparable to the free activation enthalpy of the alternative reaction pathway, the release of a nucleobase. The gas-phase behavior of tcDNA duplexes illustrates the impact of the activation entropy on the fragmentation kinetics and suggests that tandem mass spectrometric experiments are not suited to determine the relative stability of different types of nucleic acid duplexes.

  6. The Contribution of the Activation Entropy to the Gas-Phase Stability of Modified Nucleic Acid Duplexes

    Hari, Yvonne; Dugovič, Branislav; Istrate, Alena; Fignolé, Annabel; Leumann, Christian J.; Schürch, Stefan

    2016-04-01

    Tricyclo-DNA (tcDNA) is a sugar-modified analogue of DNA currently tested for the treatment of Duchenne muscular dystrophy in an antisense approach. Tandem mass spectrometry plays a key role in modern medical diagnostics and has become a widespread technique for the structure elucidation and quantification of antisense oligonucleotides. Herein, mechanistic aspects of the fragmentation of tcDNA are discussed, which lay the basis for reliable sequencing and quantification of the antisense oligonucleotide. Excellent selectivity of tcDNA for complementary RNA is demonstrated in direct competition experiments. Moreover, the kinetic stability and fragmentation pattern of matched and mismatched tcDNA heteroduplexes were investigated and compared with non-modified DNA and RNA duplexes. Although the separation of the constituting strands is the entropy-favored fragmentation pathway of all nucleic acid duplexes, it was found to be only a minor pathway of tcDNA duplexes. The modified hybrid duplexes preferentially undergo neutral base loss and backbone cleavage. This difference is due to the low activation entropy for the strand dissociation of modified duplexes that arises from the conformational constraint of the tc-sugar-moiety. The low activation entropy results in a relatively high free activation enthalpy for the dissociation comparable to the free activation enthalpy of the alternative reaction pathway, the release of a nucleobase. The gas-phase behavior of tcDNA duplexes illustrates the impact of the activation entropy on the fragmentation kinetics and suggests that tandem mass spectrometric experiments are not suited to determine the relative stability of different types of nucleic acid duplexes.

  7. Health Hazard Evaluations

    ... and Products Programs Contact NIOSH HHE Media Health Hazard Evaluations (HHEs) Language: English en Español Recommend on ... officials, or employers can ask the NIOSH Health Hazard Evaluation (HHE) Program to help learn whether health ...

  8. Development of a Gas Chromatography-Mass Spectrometry Method for the Quantification of Glucaric Acid Derivatives in Beverage Substrates

    Ana Paula Craig

    2014-01-01

    Full Text Available A gas chromatography-mass spectrometry (GC-MS method using the standard addition methodology was developed for the determination of glucuronolactone (GL and glucuronic acid (DGuA in four beverages categorized as detoxification, recovery, or energy drinks. The method features a precolumn derivatization step with a combination of BSTFA (N,O-bis(trimethylsilyltrifluoroacetamide and TMCS (trimethylchlorosilane to silylate the analytes. The sample pretreatment required no extraction, filtration, or reduction step prior to the injection. The quantification of the analytes was performed using a five-point standard addition protocol. The proposed method presented excellent intraday precision (%RSD 0.995 and acceptable linearity for DGuA calibration curves (correlation coefficients > 0.97. The estimated limits of detection (LOD and quantification (LOQ for GL ranged from 0.006 ppm to 0.14 ppm, and 0.02 ppm to 0.47 ppm, respectively. The estimated LOD and LOQ for DGuA determination ranged, respectively, from 0.06 ppm to 1.1 ppm and 0.2 ppm to 3.8 ppm. The results demonstrated that the method should be regarded as a reliable alternative to the simultaneous determination of GL and DGuA.

  9. Development of a gas chromatography-mass spectrometry method for the quantification of glucaric Acid derivatives in beverage substrates.

    Craig, Ana Paula; Fields, Christine C; Simpson, John V

    2014-01-01

    A gas chromatography-mass spectrometry (GC-MS) method using the standard addition methodology was developed for the determination of glucuronolactone (GL) and glucuronic acid (DGuA) in four beverages categorized as detoxification, recovery, or energy drinks. The method features a precolumn derivatization step with a combination of BSTFA (N,O-bis(trimethylsilyl)trifluoroacetamide) and TMCS (trimethylchlorosilane) to silylate the analytes. The sample pretreatment required no extraction, filtration, or reduction step prior to the injection. The quantification of the analytes was performed using a five-point standard addition protocol. The proposed method presented excellent intraday precision (%RSD 0.995) and acceptable linearity for DGuA calibration curves (correlation coefficients > 0.97). The estimated limits of detection (LOD) and quantification (LOQ) for GL ranged from 0.006 ppm to 0.14 ppm, and 0.02 ppm to 0.47 ppm, respectively. The estimated LOD and LOQ for DGuA determination ranged, respectively, from 0.06 ppm to 1.1 ppm and 0.2 ppm to 3.8 ppm. The results demonstrated that the method should be regarded as a reliable alternative to the simultaneous determination of GL and DGuA. PMID:25024704

  10. Study of polyaniline doped with trifluoromethane sulfonic acid in gas-diffusion electrodes for proton-exchange membrane fuel cells

    Gharibi, Hussein; Zhiani, Mohammad; Kheirmand, Mehdi; Kakaei, Karim [Department of Physical Chemistry, Faculty of Science, Tarbiat Modarres University, P.O. Box 14115-175, Tehran (Iran); Entezami, Ali Akbar [Faculty of Chemistry, Tabriz University, Tabriz (Iran); Mirzaie, Rasol Abdullah [Department of Chemistry, Faculty of Science, Shahid Rajaee University, Tehran (Iran)

    2006-04-21

    Polytetrafluoroethylene (PTFE)-bonded gas-diffusion electrodes (GDEs), modified with polyaniline as an electron and proton conductor in the catalyst layer, are prepared and evaluated for use in proton-exchange membrane fuel cells (PEMFCs). Polyaniline is coated on the GDE by electropolymerization of aniline and trifluoromethane sulfonic acid as the proton-conductive monomer. The electrodes are characterized by cyclic voltammetry, current-potential measurements, electrochemical impedance spectroscopy, and chronoamperometry. The polyaniline is found to be homogenously dispersed in the catalyst layer, making it a good candidate proton and electron conductor. Use of polyaniline instead of Nafion in the catalyst layer, increases the utility of the electrocatalyst by 18%. The results are consistent with the presence of polyaniline as a conductive polymer in the reaction layer reducing the polarization resistance of the electrode in comparison with that of a corresponding electrode containing Nafion. Thus, the present results indicate that PEMFCs using polyaniline-containing electrocatalysts should give superior performance to those using catalysts containing traditional ionomers. (author)

  11. Simultaneous quantitative determination of alpha-ketoglutaric acid and 5-hydroxymethylfurfural in human plasma by gas chromatography-mass spectrometry.

    Wagner, Bernhard M; Donnarumma, Fabrizio; Wintersteiger, Reinhold; Windischhofer, Werner; Leis, Hans J

    2010-04-01

    Alpha-ketoglutaric acid (alpha-KG) and 5-hydroxymethylfurfural (5-HMF) are currently under investigation as promising cancer cell damaging agents. A method for the simultaneous quantitative determination of alpha-KG and 5-HMF in human plasma was established for screening these compounds in human plasma. Plasma samples were directly treated with O-(2,3,4,5,6-pentafluorobenzyl) hydroxylamine hydrochloride to form the corresponding oximes, thus facilitating subsequent liquid-liquid extraction. After formation of the trimethylsilyl ethers, samples were analyzed by gas chromatography with electron ionization mass spectrometry. Stable isotope labeled standards were used, the preparation of (13)C(6)-5-HMF is described. Limits of quantitation were set to 0.938 microg/mL for alpha-KG and 0.156 microg/mL for 5-HMF. Inter-day accuracy was < or = 93.7% (alpha-KG) and < or = 92.8% (5-HMF). Inter-day precision was < or = 6.0% (alpha-KG) and < or = 4.6% (5-HMF). The method has been successfully applied to pharmacokinetic profiling of the compounds after intravenous application. PMID:20155414

  12. The effect of H2SO4 – amine clustering on chemical ionization mass spectrometry (CIMS) measurements of gas-phase sulfuric acid

    Worsnop, D.R.; Mauldin, L.; Vehkamäki, H.; M. Ehn; Junninen, H.; Sipilä, M.; Ortega, I.K.; Smith,J; T. Petäjä; Kurtén, T.; M. Kulmala

    2011-01-01

    The state-of-the art method for measuring atmospheric gas-phase sulfuric acid is chemical ionization mass spectrometry (CIMS) based on nitrate reagent ions. We have assessed the possible effect of the sulfuric acid molecules clustering with base molecules on CIMS measurements using computational chemistry. From the computational data, three conclusions can be drawn. First, a significant fraction of the gas-phase sulfuric acid molecules are very likely clustered with amines if the amine concen...

  13. Hazardous waste operational plan for site 300

    This plan outlines the procedures and operations used at LLNL's Site 300 for the management of the hazardous waste generated. This waste consists primarily of depleted uranium (a by-product of U-235 enrichment), beryllium, small quantities of analytical chemicals, industrial type waste such as solvents, cleaning acids, photographic chemicals, etc., and explosives. This plan details the operations generating this waste, the proper handling of this material and the procedures used to treat or dispose of the hazardous waste. A considerable amount of information found in this plan was extracted from the Site 300 Safety and Operational Manual written by Site 300 Facility personnel and the Hazards Control Department

  14. Hazardous waste operational plan for site 300

    Roberts, R.S.

    1982-02-12

    This plan outlines the procedures and operations used at LLNL's Site 300 for the management of the hazardous waste generated. This waste consists primarily of depleted uranium (a by-product of U-235 enrichment), beryllium, small quantities of analytical chemicals, industrial type waste such as solvents, cleaning acids, photographic chemicals, etc., and explosives. This plan details the operations generating this waste, the proper handling of this material and the procedures used to treat or dispose of the hazardous waste. A considerable amount of information found in this plan was extracted from the Site 300 Safety and Operational Manual written by Site 300 Facility personnel and the Hazards Control Department.

  15. Technology of salt resistance and acid gas pollution resistance drilling fluid for carbonate reservoir in sour gas field%酸性气田碳酸盐岩储层抗盐抗酸性气钻井液技术

    刘晓栋; 崔应中; 王宇宾

    2011-01-01

    为预测酸性气田钻井作业所用钻井液中酸性气的侵入量,根据地质参数和钻井参数计算了现场酸性气侵入量和除硫剂碱式碳酸锌与二氧化碳清除剂氧化钙的加量.为评价酸性气污染对钻井液性能的影响,设计了一套酸性气对钻井液污染的室内评价方法——气瓶压力控制灌注法,并根据理想气体状态方程,推导了灌注不同浓度酸性气体所需要的灌注压力计算公式.室内采用此方法评价了H2S、CO2对适合于南帕斯气田碳酸盐岩储层无黏土相NaCl盐水钻井液和无固相甲酸钾有机盐钻井液体系性能的影响,实验表明两套钻井液体系具有能够抗200 mg/LH2S、1000 mg/L CO2酸性气污染的能力,以及抗灰岩钻屑、地层盐水和各种盐相污染能力,且具有优越的流变性能、润滑性能、防腐蚀性能和储层保护效果,能够满足南帕斯酸性气田碳酸岩储层安全、快速、高效钻井.%In order to predict the volume of acid gas intruded into drilling fluid for drilling in sour gas field, the acid gas invaded volume and dosage of sulfide scavenger basic zinc carbonate and carbon dioxide scavenger calcium oxide were calculated on-site according to the geological parameters and drilling parameters. To evaluate the impact of acid gas pollution on the drilling fluid performance, an indoor evaluation method "gas perfusion by control cylinder pressure" was designed. And then the required perfusion pressure formulas for infusing different concentration of acid gas were developed according to ideal gas state equation. Using this experiment method we evaluated the influence of acid gas H2S and CO2 on clay-free NaCl brine drilling fluid system and solid-free potassium formate organic salt drilling fluid system that suit for carbonate reservoir of sour gas field. The results show that the two series drilling fluid system have the resistance capacity of 200 mg/L H2S, 1000 mg/L CO2 acid gas pollution, and

  16. Hazard function theory for nonstationary natural hazards

    Read, Laura K.; Vogel, Richard M.

    2016-04-01

    Impact from natural hazards is a shared global problem that causes tremendous loss of life and property, economic cost, and damage to the environment. Increasingly, many natural processes show evidence of nonstationary behavior including wind speeds, landslides, wildfires, precipitation, streamflow, sea levels, and earthquakes. Traditional probabilistic analysis of natural hazards based on peaks over threshold (POT) generally assumes stationarity in the magnitudes and arrivals of events, i.e., that the probability of exceedance of some critical event is constant through time. Given increasing evidence of trends in natural hazards, new methods are needed to characterize their probabilistic behavior. The well-developed field of hazard function analysis (HFA) is ideally suited to this problem because its primary goal is to describe changes in the exceedance probability of an event over time. HFA is widely used in medicine, manufacturing, actuarial statistics, reliability engineering, economics, and elsewhere. HFA provides a rich theory to relate the natural hazard event series (X) with its failure time series (T), enabling computation of corresponding average return periods, risk, and reliabilities associated with nonstationary event series. This work investigates the suitability of HFA to characterize nonstationary natural hazards whose POT magnitudes are assumed to follow the widely applied generalized Pareto model. We derive the hazard function for this case and demonstrate how metrics such as reliability and average return period are impacted by nonstationarity and discuss the implications for planning and design. Our theoretical analysis linking hazard random variable X with corresponding failure time series T should have application to a wide class of natural hazards with opportunities for future extensions.

  17. Hazardous Waste Roundup

    Farenga, Stephen J.; Joyce, Beverly A.; Ness, Daniel

    2004-01-01

    According to the Environmental Protection Agency (EPA), Americans generate approximately 1.6 million tons of hazardous household waste every year. When most people think of hazardous waste, they generally think of materials used in construction, the defense industry, mining, manufacturing, and agriculture. Few people think of hazardous substances…

  18. Regulation of N2O and NOx emission patterns in six acid temperate beech forest soils by soil gas diffusivity, N turnover, and atmospheric NOx concentrations

    Eickenscheidt, Nadine; Brumme, Rainer

    2013-01-01

    Low gas diffusivity of the litter layer is held responsible for high seasonal nitrous oxide (N2O) and low nitric oxide (NO) emissions from acid beech forest soils with moder type humus. The objectives were (i) to evaluate whether these beech forest soils generally exhibit high seasonal N2O emissions and (ii) to assess the influence of gas diffusivity and nitrogen (N) mineralisation on N oxide fluxes.We measured N2O and NOx (NO + NO2) fluxes in six German beech stands and determined net N turn...

  19. Periodic DFT study of acidic trace atmospheric gas molecule adsorption on Ca and Fe doped MgO (001) surface basic sites

    Baltrusaitis, Jonas; Hatch, Courtney; Orlando, Roberto

    2012-01-01

    The electronic properties of undoped and Ca or Fe doped MgO (001) surfaces, as well as their propensity towards atmospheric acidic gas (CO2, SO2 and NO2) uptake was investigated with an emphasis on gas adsorption on the basic MgO oxygen surface sites, Osurf, using periodic Density Functional Theory (DFT) calculations. Adsorption energy calculations show that MgO doping will provide stronger interactions of the adsorbate with the Osurf sites than the undoped MgO for a given adsorbate molecule....

  20. Application of headspace solid-phase microextraction followed by gas chromatography–mass spectrometry to determine short-chain alkane monocarboxylic acids in aqueous samples

    Banel, Anna; Wasielewska, Marta; Zygmunt, Bogdan

    2010-01-01

    In this study, a procedure was developed to determine short-chain alkane monocarboxylic acids (SCMAs) in aqueous samples using headspace solid-phase microextraction (HS-SPME) followed by gas chromatography (GC) coupled with mass spectrometry (MS). A Stabilwax-DA capillary column (30 m × 0.32-mm inner diameter, 0.50-μm film thickness) was used for GC separation and a 60-μm poly(ethylene glycol) fiber was used to isolate SCMAs from water and introduce them into the gas chromatograph. Parameters...

  1. A quantitative headspace-solid-phase microextraction-gas chromatography-flame ionization detector method to analyze short chain free fatty acids in rat feces.

    Fiorini, Dennis; Boarelli, Maria Chiara; Gabbianelli, Rosita; Ballini, Roberto; Pacetti, Deborah

    2016-09-01

    This study sought to develop and validate a quantitative method to analyze short chain free fatty acids (SCFAs) in rat feces by solid-phase microextraction and gas chromatography (SPME-GC) using the salt mixture ammonium sulfate and sodium dihydrogen phosphate as salting out agent. Conditioning and extraction time, linearity, limits of detection and quantification, repeatability, and recovery were evaluated. The proposed method allows quantification with improved sensitivity as compared with other methods exploiting SPME-GC. The method has been applied to analyze rat fecal samples, quantifying acetic, propionic, isobutyric, butyric, isopentanoic, pentanoic, and hexanoic acids. PMID:27267560

  2. Improved method for the determination of the major neutral steroids and unconjugated bile acids in human faeces using capillary gas chromatography.

    Bailey, E; Brooks, A G; Purchase, R; Meakings, M; Davies, M; Walters, D G

    1987-10-01

    An improved method has been developed for the determination of the major neutral steroids (cholesterol and 5 beta-cholestan-3 beta-ol) and unconjugated bile acids (deoxycholic acid and lithocholic acid) in human faeces, using capillary gas chromatography with flame ionization detection. The freeze-dried faecal sample was subjected to a two-stage Soxhlet extraction followed by an aqueous alkali-organic solvent partition step to separate neutral steroids from bile acids. The neutral steroids were analysed as their trimethylsilyl ether derivatives on an OV-1 capillary column. The bile acids were further purified on a Sep-Pak C18 cartridge and then fractionated on a Sep-Pak SIL cartridge. Unconjugated bile acids were analysed as their methyl ester-trimethylsilyl ether derivatives also on an OV-1 capillary column. Quantitation of neutral steroids and unconjugated bile acids was achieved by reference to appropriate internal standards, added to the faecal extract immediately after the Soxhlet extraction stage. The method is being used in a study of the effect of diet on the metabolic activity of human gut flora. PMID:3429569

  3. Optimization of a gas chromatography-mass spectrometry method with methyl chloroformate derivatization for quantification of amino acids in plant tissue.

    Vancompernolle, Bram; Croes, Kim; Angenon, Geert

    2016-04-01

    Rapid, easy and reliable quantification of amino acids is crucial in research on plant amino acid metabolism and nutritional improvement of crops via enrichment of essential amino acids. A recently reported analysis method, based on solid phase extraction (SPE), derivatization with methyl chloroformate and gas chromatography-mass spectrometry was optimized and tested on three-week-old Arabidopsis thaliana leaf tissues. Optimization of the SPE cleanup yielded recovery rates of minimum 95% for all amino acids (except arginine). Variations in accuracy and precision did not exceed 12.5%, except for cysteine, histidine and tryptophane, which were excluded from analysis. Quantification of overlapping peaks for isoleucine/threonine and proline/asparagine was possible by selection of two specific fragment ions for each amino acid. Of the 16 selected amino acids, 14 were quantified successfully in at least 75% of the samples, while methionine and tyrosine were only quantifiable in 6% and 42%, respectively. A case study on the aspartate super pathway confirmed the applicability of the optimized method on wild type and genetically modified plants: external supplementation of methionine or lysine yielded a 146-fold or 27-fold increase in the respective absolute amino acid levels compared with the control treatment. Induced expression of dhdps-r1 (a mutated lysine biosynthesis gene encoding a feedback insensitive enzyme) caused an 83-fold increase in absolute lysine levels. PMID:26994331

  4. Hazard Analysis Database Report

    The Hazard Analysis Database was developed in conjunction with the hazard analysis activities conducted in accordance with DOE-STD-3009-94, Preparation Guide for U S . Department of Energy Nonreactor Nuclear Facility Safety Analysis Reports, for HNF-SD-WM-SAR-067, Tank Farms Final Safety Analysis Report (FSAR). The FSAR is part of the approved Authorization Basis (AB) for the River Protection Project (RPP). This document describes, identifies, and defines the contents and structure of the Tank Farms FSAR Hazard Analysis Database and documents the configuration control changes made to the database. The Hazard Analysis Database contains the collection of information generated during the initial hazard evaluations and the subsequent hazard and accident analysis activities. The Hazard Analysis Database supports the preparation of Chapters 3 ,4 , and 5 of the Tank Farms FSAR and the Unreviewed Safety Question (USQ) process and consists of two major, interrelated data sets: (1) Hazard Analysis Database: Data from the results of the hazard evaluations, and (2) Hazard Topography Database: Data from the system familiarization and hazard identification

  5. Hazard Analysis Database Report

    GRAMS, W.H.

    2000-12-28

    The Hazard Analysis Database was developed in conjunction with the hazard analysis activities conducted in accordance with DOE-STD-3009-94, Preparation Guide for U S . Department of Energy Nonreactor Nuclear Facility Safety Analysis Reports, for HNF-SD-WM-SAR-067, Tank Farms Final Safety Analysis Report (FSAR). The FSAR is part of the approved Authorization Basis (AB) for the River Protection Project (RPP). This document describes, identifies, and defines the contents and structure of the Tank Farms FSAR Hazard Analysis Database and documents the configuration control changes made to the database. The Hazard Analysis Database contains the collection of information generated during the initial hazard evaluations and the subsequent hazard and accident analysis activities. The Hazard Analysis Database supports the preparation of Chapters 3 ,4 , and 5 of the Tank Farms FSAR and the Unreviewed Safety Question (USQ) process and consists of two major, interrelated data sets: (1) Hazard Analysis Database: Data from the results of the hazard evaluations, and (2) Hazard Topography Database: Data from the system familiarization and hazard identification.

  6. Hazard function theory for nonstationary natural hazards

    Read, Laura K.; Vogel, Richard M.

    2016-01-01

    Impact from natural hazards is a shared global problem that causes tremendous loss of life and property, economic cost, and damage to the environment. Increasingly, many natural processes show evidence of nonstationary behavior including wind speeds, landslides, wildfires, precipitation, streamflow, sea levels, and earthquakes. Traditional probabilistic analysis of natural hazards based on peaks over threshold (POT) generally assumes stationarity in the magnitudes and arriva...

  7. Hydrogen Oxidation on Gas Diffusion Electrodes for Phosphoric Acid Fuel Cells in the Presence of Carbon Monoxide and Oxygen

    Gang, Xiao; Li, Qingfeng; Hjuler, Hans Aage;

    1995-01-01

    Hydrogen oxidation has been studied on a carbon-supported platinum gas diffusion electrode in a phosphoric acidelectrolyte in the presence of carbon monoxide and oxygen in the feed gas. The poisoning effect of carbon monoxide presentin the feed gas was measured in the temperature range from 80...

  8. Pulmonary gas exchange and acid-base state at 5,260 m in high-altitude Bolivians and acclimatized lowlanders

    Wagner, Hans Peter; Araoz, Mauricio; Boushel, Robert Christopher;

    2002-01-01

    Pulmonary gas exchange and acid-base state were compared in nine Danish lowlanders (L) acclimatized to 5,260 m for 9 wk and seven native Bolivian residents (N) of La Paz (altitude 3,600-4,100 m) brought acutely to this altitude. We evaluated normalcy of arterial pH and assessed pulmonary gas...... exchange and acid-base balance at rest and during peak exercise when breathing room air and 55% O2. Despite 9 wk at 5,260 m and considerable renal bicarbonate excretion (arterial plasma HCO3- concentration = 15.1 meq/l), resting arterial pH in L was 7.48 +/- 0.007 (significantly greater than 7...

  9. Prevalence of hazardous exposures in veterinary practice

    All female graduates of a major U.S. veterinary school were surveyed by mailed questionnaire to obtain details of work practice and hazard exposure during the most recent year worked and during all pregnancies. Exposure questions were based on previously implicated occupational hazards which included anesthetic gases, radiation, zoonoses, prostaglandins, vaccines, physical trauma, and pesticides. The response rate was 86% (462/537). We found that practice type and pregnancy status were major determinants of hazard exposure within the veterinary profession. Small-animal practitioners reported the highest rates of exposure to anesthetic gas (94%), X-ray (90%), and pesticides (57%). Large-animal practitioners reported greater rates of trauma (64%) and potential exposure to prostaglandins (92%), Brucella abortus vaccine (23%), and carbon monoxide (18%). Potentially hazardous workplace practices or equipment were common. Forty-one percent of respondents who reported taking X-rays did not wear film badges, and 76% reported physically restraining animals for X-ray procedures. Twenty-seven percent of the respondents exposed to anesthetic gases worked at facilities which did not have waste anesthetic gas scavenging systems. Women who worked as veterinarians during a pregnancy attempted to reduce exposures to X-rays, insecticides, and other potentially hazardous exposures. Some potentially hazardous workplace exposures are common in veterinary practice, and measures to educate workers and to reduce these exposures should not await demonstration of adverse health effects

  10. Effects of phosphoric acid sprayed into an incinerator furnace on the flue gas pressure drop at fabric filters.

    Takahashi, Shigetoshi; Hwang, In-Hee; Matsuto, Toshihiko

    2016-06-01

    Fabric filters are widely used to remove dust from flue gas generated by waste incineration. However, a pressure drop occurs at the filters, caused by growth of a dust layer on the filter fabric despite regular cleaning by pulsed-jet air. The pressure drop at the fabric filters leads to energy consumption at induced draft fan to keep the incinerator on negative pressure, so that its proper control is important to operate incineration facility efficiently. The pressure drop at fabric filters decreased whenever phosphoric acid wastewater (PAW) was sprayed into an incinerator for treating industrial waste. Operational data obtained from the incineration facility were analyzed to determine the short- and long-term effects of PAW spraying on the pressure drop. For the short-term effect, it was confirmed that the pressure drop at the fabric filters always decreased to 0.3-1.2kPa within about 5h after spraying PAW. This effect was expected to be obtained by about one third of present PAW spraying amount. However, from the long-term perspective, the pressure drop showed an increase in the periods of PAW spraying compared with periods for which PAW spraying was not performed. The pressure drop increase was particularly noticeable after the initial PAW spraying, regardless of the age and type of fabric filters used. These results suggest that present PAW spraying causes a temporary pressure drop reduction, leading to short-term energy consumption savings; however, it also causes an increase of the pressure drop over the long-term, degrading the overall operating conditions. Thus, appropriate PAW spraying conditions are needed to make effective use of PAW to reduce the pressure drop at fabric filters from a short- and long-term point of view. PMID:27040089

  11. An uncooked vegan diet shifts the profile of human fecal microflora: computerized analysis of direct stool sample gas-liquid chromatography profiles of bacterial cellular fatty acids.

    Peltonen, R; Ling, W H; Hänninen, O.; Eerola, E

    1992-01-01

    The effect of an uncooked extreme vegan diet on fecal microflora was studied by direct stool sample gas-liquid chromatography (GLC) of bacterial cellular fatty acids and by quantitative bacterial culture by using classical microbiological techniques of isolation, identification, and enumeration of different bacterial species. Eighteen volunteers were divided randomly into two groups. The test group received an uncooked vegan diet for 1 month and a conventional diet of mixed Western type for t...

  12. Combined Determination of Poly-β-Hydroxyalkanoic and Cellular Fatty Acids in Starved Marine Bacteria and Sewage Sludge by Gas Chromatography with Flame Ionization or Mass Spectrometry Detection

    Odham, Göran; Tunlid, Anders; Westerdahl, Gunilla; Mårdén, Per

    1986-01-01

    Extraction of lipids from bacterial cells or sewage sludge samples followed by simple and rapid extraction procedures and room temperature esterification with pentafluorobenzylbromide allowed combined determinations of poly-β-hydroxyalkanoate constituents and fatty acids. Capillary gas chromatography and flame ionization or mass spectrometric detection was used. Flame ionization permitted determination with a coefficient of variation ranging from 10 to 27% at the picomolar level, whereas quan...

  13. Preliminary Study on the Effect of Ethylene Diamine- n, n-diacetic Acid on Methane Gas Production Rate from Cow Manure

    Nwokem N Calvin

    2014-09-01

    Full Text Available In an effort to improve methane gas production rate from cattle slurry; ethylene diamine- N, N-diacetic acid chelating ligand was introduced into the digester system. Experimental analysis involving the determination of trace metals, pH and methane gas yield, were carried out with the use of the Flame Atomic Absorption Spectrophotometer and Biogas5000 analyser. The results showed that there was an increase in the pH of the system; the amount of methane gas yield equally increased by 12% and the Hydraulic Retention Time decreased from 50 days to 25 days on addition of ethylene diamine- N, N-diacetic acid chelating ligand. Also, increasing the concentration of the chelating ligand further decreased the HRT of the digester system from 25 days to 19days. Concentration of trace metals like Iron, Cobalt and Nickel within the digester system ranged from 0.001-0.050 mg/L; these metals reacted with ethylene diamine- N, N-diacetic acid chelating ligand to form metal chelates. The metal chelate formed resulted in the catalysis of the hydrolysis stage (which is the rate determining step of the anaerobic digestion process. Thus, the decrease in HRT was due to the metal chelate catalysis of the hydrolysis stage of the anaerobic digestion process were the metal chelate formation served as the driving force in the solvolysis process.

  14. Simultaneous Determination of Melamine, Ammelide, Ammeline, and Cyanuric Acid in Milk and Milk Products by Gas Chromatography-tandem Mass Spectrometry

    HONG MIAO; SAI FAN; YONG-NING WU; LEI ZHANG; PING-PING ZHOU; JING-GUANG LI; HUI-JING CHEN; YUN-FENG ZHAO

    2009-01-01

    Objective To develop an analytical method for simultaneously qualitative and quantitative determination of melamine and triazine-related by-products including ammelide, ammeline, and cyanuric acid in milk and milk products by gas chromatography-tandem mass spectrometry (GC-MS/MS). Methods Melamine and triazine-related by-products namely ammelide, ammeline and cyanuric acid in the samples were extracted in a solvent mixture of diethylamine, water, and acetonitrile (10:40:50, V/V/V). After centrifugation, an aliquot of the supernatant was evaporated to dryness under a gentle stream of nitrogen gas, and then melamine and triazine-related by-products were derivatized using BSTFA with 1% TMCS. The derivatives of melamine and its analogues were determined by gas chromatography/ tandem mass spectrometry using multiple reactional monitoring (MRM) with 2, 6-Diamino-4-chloropyrimidine (DACP) being used as an internal standard. Results The linear detectable ranges were from 0.004 mg/kg to 1.6 mg/kg for melamine, ammelide, ammeline, and cyanuric acid with a correlation coefficient no less than 0.999. The recovery rates of the four compounds in spiked blank milk powder at concentrations 0.5, 1, 2 mg/kg were between 61.4%-117.2%, and the relative standard deviation was no more than 11.5% (n=6). The detection limits of melamine, ammelide, ammeline and cyanuric acid in milk powder were 0.002 mg/kg with a ratio of signal to noise of 3. Conclusion This GC-MS/MS method for simultaneous determination of melamine, ammelide, ammeline, and cyanuric acid in milk and milk products is sensitive and specific.

  15. Formation of gas-phase carbonyls from heterogeneous oxidation of polyunsaturated fatty acids at the air-water interface and of the sea surface microlayer

    Zhou, S.; Gonzalez, L.; Leithead, A.; Finewax, Z.; Thalman, R.; Vlasenko, A.; Vagle, S.; Miller, L.; Li, S.-M.; Bureekul, S.; Furutani, H.; Uematsu, M.; Volkamer, R.; Abbatt, J.

    2013-07-01

    Motivated by the potential for reactive heterogeneous chemistry occurring at the ocean surface, gas-phase products were observed when a reactive sea surface microlayer (SML) component, i.e. the polyunsaturated fatty acid (PUFA) linoleic acid (LA), was exposed to gas-phase ozone at the air-seawater interface. Similar oxidation experiments were conducted with SML samples collected from two different oceanic locations, in the eastern equatorial Pacific Ocean and from the west coast of Canada. Online proton-transfer-reaction mass spectrometry (PTR-MS) and light-emitting diode cavity enhanced differential optical absorption spectroscopy (LED-CE-DOAS) were used to detect oxygenated gas-phase products from the ozonolysis reactions. The LA studies indicate that oxidation of a PUFA monolayer on seawater gives rise to prompt and efficient formation of gas phase aldehydes. The products are formed via the decomposition of primary ozonides which form upon the initial reaction of ozone with the carbon-carbon double bonds in the PUFA molecules. In addition, two highly reactive di-carbonyls, malondialdehyde (MDA) and glyoxal, were also generated, likely as secondary products. Specific yields relative to reactant loss were 78%, 29%, 4% and atmosphere of the marine boundary layer is discussed.

  16. Gas chromatography-mass spectrometric analysis of bonded long chain fatty acids in a single zebrafish egg by ultrasound-assisted one-step transmethylation and extraction

    Li Jianjian; Yue Yingxia; Li Tingting; Hu Xuejiao [Key Laboratory of Pesticides and Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan, Hubei 430079 (China); Zhong Hongying, E-mail: hyzhong@mail.ccnu.edu.cn [Key Laboratory of Pesticides and Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan, Hubei 430079 (China)

    2009-09-21

    Changes in the level of lipid composition in a single zebrafish egg have been involved in biological responses to chemical exposures. In this paper, an one-step transmethylation of lipids and simultaneous extraction of resultant fatty acid methyl esters followed by gas chromatography-mass spectrometric analysis was developed for the identification of bonded long chain fatty acids in a single zebrafish egg. The efficiency of transmethylation under different experimental conditions has been investigated. Dried egg homogenates were directly mixed with either 0.5 M NaOH or 1% H{sub 2}SO{sub 4} or 4% HCl solution of methanol and then an n-hexane solution was added on the top. Ultrasonication of this immiscible liquid-liquid-solid system produces high velocity impacts between solid particles and liquid phases and thus promotes mass transfer among phases. It was demonstrated that ultrasound irradiation has strong effect on the alkaline-catalyzed transmethylation of lipids but cannot significantly change the acid-catalyzed transmethylation of lipids. With the aid of ultrasonication, transmethylation can be combined with simultaneous extraction of the resultant fatty acid methyl esters into n-hexane phase. This approach simplifies the sample preparation procedure, shortens the reaction time but improves the efficiency of the transmethylation of lipids and reduces sample losses, especially for small size samples. It has been applied to determine bonded fatty acids in a single zebrafish egg. In total, 28 fatty acids from a single zebrafish egg have been identified reproducibly.

  17. Gas chromatography-mass spectrometric analysis of bonded long chain fatty acids in a single zebrafish egg by ultrasound-assisted one-step transmethylation and extraction

    Changes in the level of lipid composition in a single zebrafish egg have been involved in biological responses to chemical exposures. In this paper, an one-step transmethylation of lipids and simultaneous extraction of resultant fatty acid methyl esters followed by gas chromatography-mass spectrometric analysis was developed for the identification of bonded long chain fatty acids in a single zebrafish egg. The efficiency of transmethylation under different experimental conditions has been investigated. Dried egg homogenates were directly mixed with either 0.5 M NaOH or 1% H2SO4 or 4% HCl solution of methanol and then an n-hexane solution was added on the top. Ultrasonication of this immiscible liquid-liquid-solid system produces high velocity impacts between solid particles and liquid phases and thus promotes mass transfer among phases. It was demonstrated that ultrasound irradiation has strong effect on the alkaline-catalyzed transmethylation of lipids but cannot significantly change the acid-catalyzed transmethylation of lipids. With the aid of ultrasonication, transmethylation can be combined with simultaneous extraction of the resultant fatty acid methyl esters into n-hexane phase. This approach simplifies the sample preparation procedure, shortens the reaction time but improves the efficiency of the transmethylation of lipids and reduces sample losses, especially for small size samples. It has been applied to determine bonded fatty acids in a single zebrafish egg. In total, 28 fatty acids from a single zebrafish egg have been identified reproducibly.

  18. Relationship between chromatographic resolution and amide structure of chiral 2-hydroxy acids as O-(-)-menthoxycarbonylated diastereomeric derivatives for enantiomeric separation on achiral gas chromatography.

    Cha, Eunju; Kim, Sohee; Lee, Kang Mi; Kim, Ho Jun; Kim, Ki Hun; Kwon, Oh-Seung; Park, Ki Duk; Lee, Jaeick

    2016-02-15

    The relationship between chromatographic resolution and amide structure of chiral 2-hydroxy acids as O-(-)-menthoxycarbonylated diastereomeric derivatives on achiral gas chromatography was investigated to elucidate the best diastereomeric conformation for enantiomeric separation of chiral 2-hydroxy acids. Thirteen chiral 2-hydroxy acids were converted into nine different diastereomeric O-(-)-menthoxycarbonylated amide derivatives using the primary, secondary and cyclic amines to achieve complete enantiomeric separation through an achiral column. Each enantiomeric pair of 2-hydroxy acids as O-(-)-menthoxycarbonylated tert-butylamide derivatives was resolved on both the DB-5 and DB-17 columns with resolution factors ranging from 1.7 to 4.8 and 1.7 to 3.4, respectively. The results revealed that the structure of the amide moiety is shown to significantly affect chromatographic resolution. In addition, O-(-)-menthoxycarbonylated tert-butylamide derivatives were shown to be the best diastereomeric conformations for enantiomeric separation of 2-hydroxy acids. When comparing with our previous O-trifluoroacetylated(-)-menthyl ester derivatization method, the present results suggested that size differences between groups attached to the chiral center and conformational rigidity can have stronger effects on resolution than the distance between chiral centers. The elution of R- and S-stereoisomers was affected by the class of amine; i.e., primary, secondary, or cyclic, regardless of the substituents on the amine group, the structure of the 2-hydroxy acid, and the polarity of the column. PMID:26800225

  19. Software safety hazard analysis

    Techniques for analyzing the safety and reliability of analog-based electronic protection systems that serve to mitigate hazards in process control systems have been developed over many years, and are reasonably well understood. An example is the protection system in a nuclear power plant. The extension of these techniques to systems which include digital computers is not well developed, and there is little consensus among software engineering experts and safety experts on how to analyze such systems. One possible technique is to extend hazard analysis to include digital computer-based systems. Software is frequently overlooked during system hazard analyses, but this is unacceptable when the software is in control of a potentially hazardous operation. In such cases, hazard analysis should be extended to fully cover the software. A method for performing software hazard analysis is proposed in this paper

  20. Gas-Phase Partial Oxidation of Lignin to Carboxylic Acids over Vanadium Pyrophosphate and Aluminum-Vanadium-Molybdenum.

    Lotfi, Samira; Boffito, Daria C; Patience, Gregory S

    2015-10-26

    Lignin is a complex polymer that is a potential feedstock for aromatic compounds and carboxylic acids by cleaving the β-O-4 and 5-5' linkages. In this work, a syringe pump atomizes an alkaline solution of lignin into a catalytic fluidized bed operating above 600 K. The vanadium heterogeneous catalysts convert all the lignin into carboxylic acids (up to 25 % selectivity), coke, carbon oxides, and hydrogen. Aluminum-vanadium-molybdenum mostly produced lactic acid (together with formic acid, acrylic acid, and maleic anhydride), whereas the vanadium pyrophosphate catalyst produced more maleic anhydride. PMID:26361086

  1. Denuder/filter sampling of organic acids and organosulfates at urban and boreal forest sites: Gas/particle distribution and possible sampling artifacts

    Kristensen, Kasper; Bilde, Merete; Aalto, Pasi P.; Petäjä, Tuukka; Glasius, Marianne

    2016-04-01

    Carboxylic acids and organosulfates comprise an important fraction of atmospheric secondary organic aerosols formed from both anthropogenic and biogenic precursors. The partitioning of these compounds between the gas and particle phase is still unclear and further research is warranted to better understand the abundance and effect of organic acids and organosulfates on the formation and properties of atmospheric aerosols. This work compares atmospheric aerosols collected at an urban and a boreal forest site using two side-by-side sampling systems; a high volume sampler (HVS) and a low volume (LVS) denuder/filter sampling system allowing for separate collection of gas- and particle-phase organics. All particle filters and denuder samples were collected at H.C. Andersen Boulevard (HCAB), Copenhagen, Denmark in the summer of 2010, and at the remote boreal forest site at Hyytiälä forestry field station in Finland in the summer of 2012. The chemical composition of gas- and particle-phase secondary organic aerosol was investigated by ultra-high performance liquid chromatography/electrospray ionization quadrupole time-of-flight mass spectrometry (UPLC/ESI-Q-TOFMS), with a focus on carboxylic acids and organosulfates. Results show gas-phase concentrations higher than those observed in the particle phase by a factor of 5-6 in HCAB 2010 and 50-80 in Hyytiälä 2012. Although abundant in the particle phase, no organosulfates were detected in the gas phase at either site. Through a comparison of samples collected by the HVS and the LVS denuder/filter sampling system we evaluate the potential artifacts associated with sampling of atmospheric aerosols. Such comparison shows that particle phase concentrations of semi-volatile organic acids obtained from the filters collected by HVS are more than two times higher than concentrations obtained from filters collected using LVS denuder/filter system. In most cases, higher concentrations of organosulfates are observed in particles

  2. Fatty Acid Profiling of Lipid A Isolated from Indigenous salmonella typhi strain by gas chromatography mass spectrometry

    Typhoid, caused by Salmonella enterica serovar Typhi (S. Typhi), is a major health problem worldwide especially in developing countries. Lipopolysaccharides are one of the main virulence factors of S. Typhi. Hydrophobic lipid A anchors the lipopolysaccharides into the bacterial outer membrane and also serves as the epicenter of endotoxicity, which is linked to the presence of several fatty acid chains. Fatty acid profiling is, therefore, very important to understand the endotoxicity of these pathogenic bacteria. To profile lipid A with respect to its fatty acid constituents, a S. Typhi was isolated from blood culture of a typhoid patient from the Faisalabad region of Pakistan. After its complete identification using biochemical and molecular techniques, this bacterium was cultivated in a fermentor. The cell pellet obtained was subjected to hot phenol process to extract and purify lipopolysaccharides. Acid hydrolysis of the lipopolysaccharides yielded lipid A, which was subjected to analyses using GC-MS after derivatization into their fatty acid methyl esters. The fatty acid methyl esters were identified on the basis of their retention times, compared with standards as well as characteristic mass fragmentation patterns of their respective mass spectra. This fatty acid profiling revealed the occurrence of dodecanoic acid (C12:0), tetradecanoic acid (C14:0), 3-hydroxy tetradecanoic acid (3-OH C14:0) and hexadecanoic acid (C16:0) in the lipid A component of S. Typhi strain with the relative percentage abundances 8.5%, 12.5%, 55.9% and 23.1%, respectively. (author)

  3. Determination of Aliphatic Acid and Ester in Ganoderma lucidum by Gas Chromatography-Time of Flight Mass Spectrometry%气相色谱-飞行时间质谱测定灵芝中脂肪酸(酯)

    李前荣; 潘振; 尹浩

    2004-01-01

    The extracts of Ganoderma lucidum capsule powder (A) and natural ganoaerma lucidum (B) have been and analyzed by gas chromatography-time of flight mass spectrometry (GC-TOFMS). A great quantity of aliphatic acid (ester)Was observed at tR= 18min and tR = 20min, including the unsaturated aliphatic acid which is valuable. The relative content of aliphatic acid in sample A was 49.6%, of which 19.4% was linoleic acid, and those in sample B was 32.6%, of which 7.0% was linoleic acid. The relative content of aliphatic acids in sample A was higher than that in sample B.

  4. Phytanic acid: measurement of plasma concentrations by gas-liquid chromatography-mass spectrometry analysis and associations with diet and other plasma fatty acids.

    Allen, Naomi E; Grace, Philip B; Ginn, Annette; Travis, Ruth C; Roddam, Andrew W; Appleby, Paul N; Key, Timothy

    2008-03-01

    Epidemiological data suggest that a diet rich in animal foods may be associated with an increased risk of several cancers, including cancers of the prostate, colorectum and breast, but the possible mechanism is unclear. It is hypothesised that phytanic acid, a C20 branched-chain fatty acid found predominantly in foods from ruminant animals, may be involved in early cancer development because it has been shown to up regulate activity of alpha-methylacyl-coenzyme A racemase, an enzyme commonly found to be over-expressed in tumour cells compared with normal tissue. However, little is known about the distribution of plasma phytanic acid concentrations or its dietary determinants in the general population. The primary aim of the present cross-sectional study was to determine circulating phytanic acid concentrations among ninety-six meat-eating, lacto-ovo-vegetarian and vegan women, aged 20-69 years, recruited into the Oxford component of the European Prospective Investigation into Cancer and Nutrition (EPIC-Oxford). Meat-eaters had, on average, a 6.7-fold higher geometric mean plasma phytanic acid concentration than the vegans (5.77 v. 0.86 micromol/l; P vegetarians (5.77 v. 3.93 micromol/l; P = 0.016). The strongest determinant of plasma phytanic acid concentration appeared to be dairy fat intake (r 0.68; P cancer development. PMID:17868488

  5. Disposal of hazardous wastes

    The Fifth Life Sciences Symposium entitled Hazardous Solid Wastes and Their Disposal on October 12 through 14, 1977 was summarized. The topic was the passage of the National Resources Conservation and Recovery Act of 1976 will force some type of action on all hazardous solid wastes. Some major points covered were: the formulation of a definition of a hazardous solid waste, assessment of long-term risk, list of specific materials or general criteria to specify the wastes of concern, Bioethics, sources of hazardous waste, industrial and agricultural wastes, coal wastes, radioactive wastes, and disposal of wastes

  6. Role of toluene to acid gas (H2S and CO2) combustion in H2/O2–N2 flame under Claus condition

    Highlights: • Examined combustion of H2S, H2S/C7H8 and H2S/C7H8/CO2 at Claus conditions (Φ = 3). • Toluene alone caused decay of formed SO2, but C7H8 and CO2 enhanced SO2 formation. • Toluene triggered formation of hydrocarbons (methane and acetylene) and CS2. • Toluene and CO2 enhanced COS and CS2 formation but enhanced decay of hydrocarbons. - Abstract: Experimental results are presented from the combustion of toluene with CO2 and H2S gas in H2/O2–N2 flames at an equivalence ratio of Φ = 3 (Claus condition). The results from the combustion of 100% H2S, H2S/C7H8 and H2S/C7H8/CO2 acid gases are also reported. The results showed a decrease in mole fraction of H2S and simultaneous evolution of SO2 in H2S/H2/O2–N2 flame. In contrast, combustion of H2S/C7H8 acid gas showed faster initial SO2 formation to a maximum mole fraction, but the formed SO2 decomposed further downstream in the reactor. This is in further contrast to that of H2S/C7H8/CO2 acid gas combustion, where CO2 acted as an oxidizer (released atomic oxygen) that furthered SO2 formation. The results also revealed the formation of CH4, C2H2 and CS2 with the addition of toluene. The presence of CO2 enhanced the formation of mercaptans (COS and CS2) and decomposition of formed hydrocarbons in the reactor. These results help to identify conditions under which hydrocarbons and mercaptans (COS and CS2) are formed, and how they can be mitigated during sulfur and energy recovery from acid gases

  7. Reclamation of acid, toxic coal spoils using wet flue gas desulfurization by-product, fly ash and sewage sludge. Final report

    Kost, D.A.; Vimmerstedt, J.P.; Stehouwer, R.C.

    1997-03-01

    Establishment of vegetation on acid abandoned minelands requires modification of soil physical and chemical conditions. Covering the acid minesoil with topsoil or borrow soil is a common practice but this method may be restricted by availability of borrow soil and cause damage to the borrow site. An alternative approach is to use waste materials as soil amendments. There is a long history of using sewage sludge and fly ash as amendments for acid minesoils. Flue gas desulfurization (FGD) by-products are newer materials that are also promising amendments. Most flue gas sludges are mixtures of Calcium sulfate (CaSO{sub 4}), calcium sulfite (CaSO{sub 3}), calcium carbonate (CaCO{sub 3}), calcium hydroxide [Ca(OH){sub 2}], and fly ash. Some scrubbing processes produce almost pure gypsum (CaSO{sub 4}2H{sub 2}O). The primary purpose of the project is to evaluate two wet FGD by-products for effects on vegetation establishment and surface and ground water quality on an acid minesoil. One by-product from the Conesville, OH power plant (American Electric Power Service Corporation) contains primarily calcium sulfite and fly ash. The other by-product (Mg-gypsum FGD) from an experimental scrubber at the Zimmer power plant (Cincinnati Gas and Electric Company) is primarily gypsum with 4% magnesium hydroxide. These materials were compared with borrow soil and sewage sludge as minesoil amendments. Combinations of each FGD sludge with sewage sludge were also tested. This report summarizes two years of measurements of chemical composition of runoff water, ground water at two depths in the subsoil, soil chemical properties, elemental composition and yield of herbaceous ground cover, and elemental composition, survival and height of trees planted on plots treated with the various amendments. The borrow soil is the control for comparison with the other treatments.

  8. Reclamation of acid, toxic coal spoils using wet flue gas desulfurization by-product, fly ash and sewage sludge. Final report

    Establishment of vegetation on acid abandoned minelands requires modification of soil physical and chemical conditions. Covering the acid minesoil with topsoil or borrow soil is a common practice but this method may be restricted by availability of borrow soil and cause damage to the borrow site. An alternative approach is to use waste materials as soil amendments. There is a long history of using sewage sludge and fly ash as amendments for acid minesoils. Flue gas desulfurization (FGD) by-products are newer materials that are also promising amendments. Most flue gas sludges are mixtures of Calcium sulfate (CaSO4), calcium sulfite (CaSO3), calcium carbonate (CaCO3), calcium hydroxide [Ca(OH)2], and fly ash. Some scrubbing processes produce almost pure gypsum (CaSO42H2O). The primary purpose of the project is to evaluate two wet FGD by-products for effects on vegetation establishment and surface and ground water quality on an acid minesoil. One by-product from the Conesville, OH power plant (American Electric Power Service Corporation) contains primarily calcium sulfite and fly ash. The other by-product (Mg-gypsum FGD) from an experimental scrubber at the Zimmer power plant (Cincinnati Gas and Electric Company) is primarily gypsum with 4% magnesium hydroxide. These materials were compared with borrow soil and sewage sludge as minesoil amendments. Combinations of each FGD sludge with sewage sludge were also tested. This report summarizes two years of measurements of chemical composition of runoff water, ground water at two depths in the subsoil, soil chemical properties, elemental composition and yield of herbaceous ground cover, and elemental composition, survival and height of trees planted on plots treated with the various amendments. The borrow soil is the control for comparison with the other treatments

  9. Simultaneous Determination of Essential Oil Components and Fatty Acids in Fennel using Gas Chromatography with a Polar Capillary Column.

    Najdoska-Bogdanov, Menče; Bogdanov, Jane B; Stefova, Marina

    2015-09-01

    Cultivated and wild growing samples of fennel (Foeniculum vulgare Mill., Apiaceae) from R. Macedonia were studied for their volatiles and fatty acid composition. The main essential oil components isolated via hydrodistillation were: trans-anethole (>80%), estragole (hexane and dichloromethane (3:1, v/v) in a Soxhlet extraction followed by transesterification. The obtained extracts were then characterized and the dominant fatty acid was 18:1 (petroselinic and oleic acid) 75.0-82.8%, followed by 18:2 (linoleic acid) 10.8-16.2% and other fatty acids: palmitic (4.3-6.9%), stearic (1.2-1.7%) and myristic (0-2.9%). The results for the volatile fraction after Soxhlet extraction and transesterification did not significantly differ from results obtained after hydrodistillation, especially for the main components (trans-anethole, estragole, fenchone and limonene), implying that the developed method can be used for simultaneous determination of volatiles and fatty acids. PMID:26594773

  10. Determination of Organic Acids in Forest Litters by a Capillary Gas Chromatography%毛细管气相色谱法测定森林凋落物中的有机酸

    宋金凤; 刘永; 崔晓阳

    2004-01-01

    Organic acids in forest litters play important role in forests and forest soils. Based on the fresh litter materials of Fraxinus mandshurica and Larix olgensis forest in northeast China, a capillary gas chromatography procedure was established to determine organic acids in forest litters. Organic acids in forest litter were lixiviated and derived into corresponding esters with 7:100 (v:v) H2SO4:CH3OH at 60℃, extracted in CHCl3 and analyzed by capillary gas chromatography (GC) system. It resulted that, the method reported in this paper to separate, identify and determine organic acids in forest litter by GC was reliable and easy to operate. The disposal of sample was convenient, and the esterification with CH3 OH occurred while extracting organic acids with the same reagent, so volatilization loss of low-molecular-weight organic acids and oxidation of unsaturated fatty acids were avoided in course of condensation and esterification at high temperature when the conventional method to determine organic acids was used. Good selectivity was obtained, low-molecular-weight organic acids and high fatty acids could be determined simultaneously and accurately. Recovery of thirteen organic acids detected by adding standard samples ranged from 84.66% to 97.45% with relative standard deviation from 1.53% to 8.54%, and lowest detection limit of different organic acids was in range of 0.39 to 6.46 ng. The method could be used to determine organic acids in forest litters with satisfactory results.

  11. Relative Hazard Calculation Methodology

    The methodology presented in this document was developed to provide a means of calculating the RH ratios to use in developing useful graphic illustrations. The RH equation, as presented in this methodology, is primarily a collection of key factors relevant to understanding the hazards and risks associated with projected risk management activities. The RH equation has the potential for much broader application than generating risk profiles. For example, it can be used to compare one risk management activity with another, instead of just comparing it to a fixed baseline as was done for the risk profiles. If the appropriate source term data are available, it could be used in its non-ratio form to estimate absolute values of the associated hazards. These estimated values of hazard could then be examined to help understand which risk management activities are addressing the higher hazard conditions at a site. Graphics could be generated from these absolute hazard values to compare high-hazard conditions. If the RH equation is used in this manner, care must be taken to specifically define and qualify the estimated absolute hazard values (e.g., identify which factors were considered and which ones tended to drive the hazard estimation)

  12. Novel characterisation of minor α-linolenic acid isomers in linseed oil by gas chromatography and covalent adduct chemical ionisation tandem mass spectrometry.

    Gómez-Cortés, P; Brenna, J T; Lawrence, P; de la Fuente, M A

    2016-06-01

    Discrimination between polyunsaturated fatty acid isomers with three double bonds is a great challenge, due to structural similarities and similar polarities. In this study, we report the identification of four minor geometrical isomers of α-linolenic acid (ALA) present in linseed oil samples: (9E,12Z,15E)-, (9Z,12Z,15E)-, (9Z,12E,15Z)- and (9E,12Z,15Z)-octadeca-9,12,15-trienoic acids, chromatographically resolved by gas chromatography (GC) using a new and highly polar ionic phase column (SLB-IL111). Gas chromatography-electron ionisation mass spectrometry (GC-EIMS) determined that the four unknown compounds were C18:3 n-3 isomers. The positional 9-12-15 C18:3 configuration was achieved by covalent adduct chemical ionisation tandem mass spectrometry (CACI-MS/MS) while geometrical configuration was established with analytical standards based on relative retention. We hypothesised that these isomers are formed during linseed oil deodorisation and postulate preferred and unfavoured isomerisation pathways of ALA. PMID:26830571

  13. Gas chromatographic detection of D-(-)-2,3-butanediol and butyric acid produced by sporeformers in cream-style corn and canned beef noodle soup: collaborative study.

    Schafer, M L; Peeler, J T; Bradshaw, J G; Hamilton, C H; Carver, R B

    1985-01-01

    A gas chromatographic method that identifies sporeformers as the cause of spoilage in swollen cans of low-acid foods was collaboratively studied in 2 stages. Two organic compounds produced by sporeformers, D-(-)-2,3-butanediol and butyric acid, are measured in the upper phase after centrifugation of the liquid portion of the can contents. Each sample is assayed on 2 packed columns designed for the assay of aqueous solutions of volatile fatty acids, using flame ionization detectors. For study 1, 16 duplicate inoculated cans of cream-style corn and beef noodle soup were sent to 9 collaborators. For study 2, 7 collaborators received 11 duplicate inoculated cans of the 2 foods. Duplicate uninoculated cans of each food served as negative controls. The inocula were 6 sporeforming organisms (4 Clostridium and 2 gas-forming Bacillus species) and 2 nonsporeformers. After the deletion of marginal samples, the percentages of correctly identified sporeformers and nonsporeformers in beef noodle soup were 83 (110/132) and 90 (54/60), respectively; corresponding percentages for cream-style corn were 80 (98/123) and 100 (35/35). The method has been adopted official first action. PMID:4030630

  14. Efficient carbon dioxide utilization and simultaneous hydrogen enrichment from off-gas of acetone-butanol-ethanol fermentation by succinic acid producing Escherichia coli.

    He, Aiyong; Kong, Xiangping; Wang, Chao; Wu, Hao; Jiang, Min; Ma, Jiangfeng; Ouyang, Pingkai

    2016-08-01

    The off-gas from acetone-butanol-ethanol (ABE) fermentation was firstly used to be CO2 source (co-substrate) for succinic acid production. The optimum ratio of H2/CO2 indicated higher CO2 partial pressures with presence of H2 could enhance C4 pathway flux and reductive product productivity. Moreover, when an inner recycling bioreactor was used for CO2 recycling at a high total pressure (0.2Mpa), a maximum succinic acid concentration of 65.7g·L(-1) was obtained, and a productivity of 0.76g·L(-1)·h(-1) and a high yield of 0.86g·g(-1) glucose were achieved. Furthermore, the hydrogen content was simultaneously enriched to 92.7%. These results showed one successful attempt to reuse the off-gas of ABE fermentation which can be an attractive CO2 source for succinic acid production. PMID:27142628

  15. Acetic Acid Dimer in the Gas Phase, Nonpolar Solvent, Microhydrated Environment, and Dilute and Concentrated Acetic Acid: Ab initio Quantum Chemical and Molecular Dynamics Simulations

    Chocholoušová, Jana; Vacek, Jaroslav; Hobza, Pavel

    2003-01-01

    Roč. 107, č. 17 (2003), s. 3086-3092. ISSN 1089-5639 R&D Projects: GA MŠk LN00A032 Institutional research plan: CEZ:AV0Z4040901 Keywords : carboxylic-acids * orbital calculations * aqueous-solution Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.792, year: 2003

  16. An optimized method for fatty acid analysis, including quantification of trans fatty acids, in human adipose tissue by gas-liquid chromatography

    Bysted, Anette; Cold, S; Hølmer, Gunhild Kofoed

    1999-01-01

    . Fatty acids ranging in carbon number from 12 to 22and with 0-6 double bonds were resolved and identified by capillary column GLC with a temperature program starting at150 degrees C. Following injection, the oven temperature was increased at a rate of 3 degrees C/min to 200 degrees C,then held constant...

  17. Pyrolysis-Gas Chromatography/Mass Spectrometry Characterization of Humic Acids in Coastal Spodosols from Southeastern Brazil

    Buurman, P.; Vidal-Torrado, P.; Martin-Neto, L.

    2012-01-01

    This study on humic acids (HAs) of podzol horizons from the southeastern region of Brazil investigated the accumulation and degradation of soil organic matter (SOM) in warm-climate podzols. Humic acids from sandy coastal Spodosols (Histic Alaquod and Arenic Alorthod) from Cardoso Island in Sao Paulo

  18. Oxygen Reduction on Gas-Diffusion Electrodes for Phosphoric Acid Fuel Cells by a Potential Decay Method

    Li, Qingfeng; Gang, Xiao; Hjuler, Hans Aage;

    1995-01-01

    The reduction of gaseous oxygen on carbon supported platinum electrodes has been studied at 150 degrees C with polarization and potential decay measurements. The electrolyte was either 100 weight percent phosphoric acid or that acid with a fluorinated additive, potassium perfluorohexanesulfonate (C...

  19. 75 FR 53371 - Liquefied Natural Gas Facilities: Obtaining Approval of Alternative Vapor-Gas Dispersion Models

    2010-08-31

    ... Pipeline and Hazardous Materials Safety Administration Liquefied Natural Gas Facilities: Obtaining Approval... Safety Administration (PHMSA) issues federal safety standards for siting liquefied natural gas (LNG...) NFPA 59A: Standard for the Production, Storage, and Handling of Liquefied Natural Gas. That...

  20. NGNP SITE 2 HAZARDS ASSESSMENT

    Wayne Moe

    2011-10-01

    The Next Generation Nuclear Plant (NGNP) Project initiated at Idaho National Laboratory (INL) by the U.S. Department of Energy pursuant to the 2005 Energy Policy Act, is based on research and development activities supported by the Generation IV Nuclear Energy Systems Initiative. The principal objective of the NGNP Project is to support commercialization of the high temperature gas-cooled reactor (HTGR) technology. The HTGR is a helium-cooled and graphite-moderated reactor that can operate at temperatures much higher than those of conventional light water reactor (LWR) technologies. Accordingly, it can be applied in many industrial applications as a substitute for burning fossil fuels, such as natural gas, to generate process heat in addition to producing electricity, which is the principal application of current LWRs. Nuclear energy in the form of LWRs has been used in the U.S. and internationally principally for the generation of electricity. However, because the HTGR operates at higher temperatures than LWRs, it can be used to displace the use of fossil fuels in many industrial applications. It also provides a carbon emission-free energy supply. For example, the energy needs for the recovery and refining of petroleum, for the petrochemical industry and for production of transportation fuels and feedstocks using coal conversion processes require process heat provided at temperatures approaching 800 C. This temperature range is readily achieved by the HTGR technology. This report summarizes a site assessment authorized by INL under the NGNP Project to determine hazards and potential challenges that site owners and HTGR designers need to be aware of when developing the HTGR design for co-location at industrial facilities, and to evaluate the site for suitability considering certain site characteristics. The objectives of the NGNP site hazard assessments are to do an initial screening of representative sites in order to identify potential challenges and restraints

  1. Fuel gas conditioning process

    Lokhandwala, Kaaeid A.

    2000-01-01

    A process for conditioning natural gas containing C.sub.3+ hydrocarbons and/or acid gas, so that it can be used as combustion fuel to run gas-powered equipment, including compressors, in the gas field or the gas processing plant. Compared with prior art processes, the invention creates lesser quantities of low-pressure gas per unit volume of fuel gas produced. Optionally, the process can also produce an NGL product.

  2. Protection of buildings from hazardous gases

    About 2500 deaths per year in the UK are attributed to radon, while incidents of deaths involving methane and carbon dioxide derived from landfills and mine gas average less than one per year. Potentially about 5% of all UK premises are at risk from contamination by these hazardous gases. This compares with a lower proportion of buildings affected by forms of previously contaminative use, which are to be collated into a register of potentially contaminated land when s. 143 of the Environmental Protection Act 1990 is implemented. The potential hazard, migration, principles of control, and design of building protection measures, are reviewed for all three gases. (author)

  3. Effects of xylazine on acid-base balance and arterial blood-gas tensions in goats under different environmental temperature and humidity conditions

    E.G.M. Mogoa

    2000-07-01

    Full Text Available The effects of acute exposure to 3 different temperature and humidity conditions on arterial blood-gas and acid-base balance in goats were investigated after intravenous bolus administration of xylazine at a dose of 0.1 mg/kg. Significant (P < 0.05 changes in the variables occurred under all 3 environmental conditions. Decreases in pH, partial pressure of oxygen and oxyhaemoglobin saturation were observed, and the minimum values for oxygen tension and oxyhaemoglobin saturation were observed within 5 min of xylazine administration. The pH decreased to its minimum values between 5 and 15 min. Thereafter, the variables started to return towards baseline, but did not reach baseline values at the end of the 60 min observation period. Increases in the partial pressure of carbon dioxide, total carbon dioxide content, bicarbonate ion concentration, and the actual base excess were observed. The maximum increase in the carbon dioxide tension occurred within 5 min of xylazine administration. The increase in the actual base excess only became significant after 30 min in all 3 environments, and maximal increases were observed at 60 min. There were no significant differences between the variables in the 3 different environments. It was concluded that intravenous xylazine administration in goats resulted in significant changes in arterial blood-gas and acid-base balance that were associated with hypoxaemia and respiratory acidosis, followed by metabolic alkalosis that continued for the duration of the observation period. Acute exposure to different environmental temperature and humidity conditions after xylazine administration did not influence the changes in arterial blood-gas and acid-base balance.

  4. Hazard screening application guide

    The basic purpose of hazard screening is to group precesses, facilities, and proposed modifications according to the magnitude of their hazards so as to determine the need for and extent of follow on safety analysis. A hazard is defined as a material, energy source, or operation that has the potential to cause injury or illness in human beings. The purpose of this document is to give guidance and provide standard methods for performing hazard screening. Hazard screening is applied to new and existing facilities and processes as well as to proposed modifications to existing facilities and processes. The hazard screening process evaluates an identified hazards in terms of the effects on people, both on-site and off-site. The process uses bounding analyses with no credit given for mitigation of an accident with the exception of certain containers meeting DOT specifications. The process is restricted to human safety issues only. Environmental effects are addressed by the environmental program. Interfaces with environmental organizations will be established in order to share information

  5. Formation of gas-phase carbonyls from heterogeneous oxidation of polyunsaturated fatty acids at the air–water interface and of the sea surface microlayer

    S. Zhou

    2013-07-01

    Full Text Available Motivated by the potential for reactive heterogeneous chemistry occurring at the ocean surface, gas-phase products were observed when a reactive sea surface microlayer (SML component, i.e. the polyunsaturated fatty acid (PUFA linoleic acid (LA, was exposed to gas-phase ozone at the air–seawater interface. Similar oxidation experiments were conducted with SML samples collected from two different oceanic locations, in the eastern equatorial Pacific Ocean and from the west coast of Canada. Online proton-transfer-reaction mass spectrometry (PTR-MS and light-emitting diode cavity enhanced differential optical absorption spectroscopy (LED-CE-DOAS were used to detect oxygenated gas-phase products from the ozonolysis reactions. The LA studies indicate that oxidation of a PUFA monolayer on seawater gives rise to prompt and efficient formation of gas phase aldehydes. The products are formed via the decomposition of primary ozonides which form upon the initial reaction of ozone with the carbon-carbon double bonds in the PUFA molecules. In addition, two highly reactive di-carbonyls, malondialdehyde (MDA and glyoxal, were also generated, likely as secondary products. Specific yields relative to reactant loss were 78%, 29%, 4% and <1% for n-hexanal, 3-nonenal, MDA and glyoxal, respectively, where the yields for MDA and glyoxal are likely lower limits. Heterogeneous oxidation of SML samples confirm for the first time that similar carbonyl products are formed via ozonolysis of environmental samples. The potential impact of such chemistry on the atmosphere of the marine boundary layer is discussed.

  6. The Role of Acidic Residues and of Sodium Ion Adduction on the Gas-Phase H/D Exchange of Peptides and Peptide Dimers

    Jurchen, John C.; Cooper, Russell E.; Williams, Evan R.

    2003-01-01

    Gas-phase H/D exchange is widely used for characterizing the structure of ions. However, many structural parameters that affect the rate of H/D exchange are poorly understood, which complicates the interpretation of experimental data. Here, the effects of sodium ion adduction on the rate of H/D exchange with D2O for a series of peptides and peptide dimers with varying numbers of acidic residues are described. The maximum number of sodium ion adducts that can be accommodated by the peptides an...

  7. The Effect of Temperature and Acid Gas Loading on Corrosion Behavior of API 5L X52 Carbon Steel in Amine Unit

    Javidi, M.; Lalehparvar, M. M.; Ghassemi, A.

    2016-05-01

    The effect of temperature and H2S concentration on amine corrosion of API 5L X52 carbon steel in a CO2-saturated 25 wt.% diethanolamine solution was investigated via electrochemical techniques. It was found that increase in temperature from 25 to 80 °C resulted in severe increase in corrosion rate from 0.88 to 16.24 mpy due to increase in degradation rate of amine. Also, it was concluded that increase in H2S concentration led to increase in corrosion rate because of formation of more heat stable amine salts. The effect of temperature on corrosion rate was more significant than acid gas loading.

  8. Working records of air dispersion modelling and environmental assessments for acid gas emissions from power stations and oil refineries

    The article assessed (i) the contributions of petroleum refineries and fossil-fuelled power plant on local air quality and acid deposition; (ii) the contribution of nitrogen oxides to acid deposition and (iii) the application of dynamic critical load modelling in assessment of the impact of acid deposition. The study includes a case study of the local impact of emissions of sulfur dioxide and nitrogen oxides from the Lindsey and Conoco refineries on the Humber and critical loading modelling for emissions from Uskmouth power station

  9. The effect of H2SO4 - amine clustering on chemical ionization mass spectrometry (CIMS) measurements of gas-phase sulfuric acid

    Kurten, T.; Petaja, T.; Smith, J.;

    2011-01-01

    chemistry. From the computational data, three conclusions can be drawn. First, a significant fraction of the gas-phase sulfuric acid molecules are very likely clustered with amines if the amine concentration is around or above a few ppt. Second, some fraction of these acid-amine clusters may not be charged...... by the CIMS instrument, though the most reliable computational methods employed predict this fraction to be small; on the order of ten percent or less. Third, the amine molecules will evaporate practically immediately after charging, thus evading detection. These effects may need to be taken into...... account in the interpretation of atmospheric measurement data obtained using chemical ionization methods. The purpose of this study is not to criticize the CIMS method, but to help understand the implications of the measured results....

  10. Moral Hazard and Stability

    Tumennasan, Norovsambuu

    2014-01-01

    Economists perceive moral hazard as an undesirable problem because it undermines efficiency. Carefully designed contracts can mitigate the moral hazard problem, but this assumes that a team is already formed. This paper demonstrates that these contracts are sometimes the reason why teams do not...... form. Formally, we study the team formation problem in which the agents’ efforts are not verifiable and the size of teams does not exceed quota r . We show that if the team members cannot make transfers, then moral hazard affects stability positively in a large class of games. For example, a stable...

  11. Effects of formic acid hydrolysis on the quantitative analysis of radiation-induced DNA base damage products assayed by gas chromatography/mass spectrometry

    Gas chromatography/mass spectrometry (GC/ MS-SIM) is an excellent technique for performing both qualitative and quantitative analysis of DNA base damage products that are formed by exposure to ionizing radiation or by the interaction of intracellular DNA with activated oxygen species. This technique commonly uses a hot formic acid hydrolysis step to degrade the DNA to individual free bases. However, due to the harsh nature of this degradation procedure, the quantitation of DNA base damage products may be adversely affected. Consequently, we examined the effects of various formic acid hydrolysis procedures on the quantitation of a number of DNA base damage products and identified several factors that can influence this quantitation. These factors included (1) the inherent acid stabilities of both the lesions and the internal standards; (2) the hydrolysis temperature; (3) the source and grade of the formic acid; and (4) the sample mass during hydrolysis. Our data also suggested that the N, O-bis (trimethylsilyl)trifluoroacetamide (BSTFA) derivatization efficiency can be adversely affected, presumably by trace contaminants either in the formic acid or from the acid-activated surface of the glass derivatization vials. Where adverse effects were noted, modifications were explored in an attempt to improve the quantitation of these DNA lesions. Although experimental steps could be taken to minimize the influence of these factors on the quantitation of some base damage products, no single procedure solved the quantitation problem for all base lesions. However, a significant improvement in the quantitation was achieved if the relative molecular response factor (RMRF) values for these lesions were generated with authentic DNA base damage products that had been treated exactly like the experimental samples. (orig.)

  12. Quantification of organic acids in particulate matter by coupling of thermally assisted hydrolysis and methylation with thermodesorption-gas chromatography-mass spectrometry.

    Beiner, K; Plewka, A; Haferkorn, S; Iinuma, Y; Engewald, W; Herrmann, H

    2009-09-18

    A quantitative method for the determination of organic acids in atmospheric particles is developed. The method couples a derivatisation step (thermally assisted hydrolysis and methylation) and a Curie point pyrolyser as a thermal desorption technique and gas chromatography-mass spectrometry (CPP-GC-MS). Among the reagents tested (tetramethylammonium hydroxide (TMAH), tetramethylammonium acetate (TMAAc) and phenyltrimethylammonium hydroxide (TMPAH)), the best performance was found using TMAAc as a derivatisation reagent for the reaction time of 4s at 510 degrees C as heating temperature. Calibration was performed for a series of fatty acids (FA), dicarboxylic acids (DCA) and terpenoic acids (TA) under these conditions. Coefficients of determination (R(2)) were between 0.94 and 0.98. Limits of detection (LOD) were in the nanogram-range between 0.1 and 3.6 ng. The method is applied on atmospheric particle samples to obtain the quantification reproducibility and quantification limits. Reproducibility was determined in terms of relative standard deviations (RSD) for ambient aerosol samples collected by a high-volume-sampler (HVS, RSD=6-45%, n=10) and a Berner impactor (BI, RSD=5-34%, n=10). Based on 24h sampling time the developed method enables quantification of all three classes of acids for both sampling techniques. Calibration data and presented volume concentrations are compared with literature data. A comparison with an off-line methylation-GC-MS using BF(3) as a derivatisation reagent and capillary electrophoresis coupled mass spectrometry (CE-MS) showed a good agreement. Minimal sample preparation is the main advantage of the developed method. Depending on the sensitivity requirements the present method can be a fast and simple alternative to GC-MS techniques with conventional sample preparation steps for semi-volatile organic acids. PMID:19679312

  13. Aromatic substitution in the gas phase. On the mechanism of the dehalogenation reactions of halobenzenes and dihalobengenes promoted by gaseous Bronsted acids

    The attack of CH5+ and C2H5+ ions, obtained in the dilute gas state from the γ radiolysis of methane, on halo- and dihalobenzenes causes extensive dehalogenation via two distinct channels, leading respectively to protodehalogenated and methyldehalogenated products, whose relative rate depends primarily on the nature of the leaving halogen. Kinetic and mass spectrometric evidences suggest that direct attack of the Bronsted acid to the halogen substituent leads to formation of the correspondent arylium cation, via hydrogen halide elimination, at a rate which decreases in the order F much greater than Cl equal to or greater than Br. The subsequent electrophilic attack of the arylium cations on CH4, the bulk constituent of the system, yields methylated arenium ions, and eventually the observed methyldehalogenated products. On the other hand, attack of the Bronsted acid to the aromatic ring of halobenzenes promotes protodehalogenation, at a rate increasing in the order F much less than Cl < Br. Direct comparison of the rates of the two dehalogenation processes has been obtained from the study of dihalobenzenes containing different halogens. Furthermore, isolation of a mixture of m- and p-xylene among the dehalogenation products of p-fluorotoluene has provided direct evidence for the isomerization of the p-tolyl cation formed from the attack of the gaseous Bronsted acid to the n-type center of the substrate and/or of the xylenium ion formed from the attack of the tolyl ion to methane. The present results, and supporting mass spectrometric evidence, underline the typical ambident behavior of halobenzenes toward charged electprophiles, and allow a unified interpretation of the dehalogention processes promoted by different Bronsted acids. The gas-phase reactivity of halobenzenes is compared with their behavior in similar processes occuring in solution

  14. Quantification of trace fatty acid methyl esters in diesel fuel by using multidimensional gas chromatography with electron and chemical ionization mass spectrometry.

    Webster, R L; Rawson, P M; Evans, D J; Marriott, P J

    2016-07-01

    Measurement of contamination of marine and naval diesel fuels (arising from product mixing or adulteration) with biodiesel or fatty acid methyl esters can be problematic, especially at very low levels. A suitable solution for this task for trace amounts of individual fatty acid methyl esters with resolution and quantification can be achieved by using a multidimensional gas chromatographic approach with electron and chemical ionization mass spectrometric detection. A unique column set comprising a 100 m methyl-siloxane nonpolar first dimension column and high-temperature ionic liquid column in the second dimension enabled identification of individual fatty acid methyl esters at below the lowest concentrations required to be reported in a diesel fuel matrix. Detection limits for individual fatty acid methyl esters compounds ranged from 0.5 to 5.0 mg/L, with excellent linearity up to 5000 mg/L and repeatability of the method from 1.3 to 3.2%. The method was applied to the analysis of diesel fuel samples with suspected biodiesel contamination. Contamination at 568 mg/L was calculated for an unknown sample and interpretation of the results permitted the determination of a likely source of the contamination. PMID:27159197

  15. Selection of Taste Markers Related to Lactic Acid Bacteria Microflora Metabolism for Chinese Traditional Paocai: A Gas Chromatography-Mass Spectrometry-Based Metabolomics Approach.

    Zhao, Nan; Zhang, Chuchu; Yang, Qin; Guo, Zhuang; Yang, Bo; Lu, Wenwei; Li, Dongyao; Tian, Fengwei; Liu, Xiaoming; Zhang, Hao; Chen, Wei

    2016-03-23

    Traditional paocai brine (PB) is continuously propagated by back-slopping and contains numerous lactic acid bacteria (LAB) strains. Although PB is important for the quality of paocai (Chinese sauerkraut), the taste features, taste-related compounds of PB-paocai and the effects of LAB communities from PB on the taste compounds remain unclear. An electronic tongue was used to evaluate the taste features of 13 PB-paocai samples. Umami, saltiness, bitterness, sweetness, and aftertaste astringency were the main taste features of PB-paocai. A total of 14 compounds were identified as discriminant taste markers for PB-paocai via gas chromatography-mass spectrometry (GC-MS)-based multimarker profiling. A LAB co-culture (Lactobacillus plantarum, Lactobacillus buchneri, and Pediococcus ethanoliduran) from PB could significantly increase glutamic acid (umami), sucrose (sweetness), glycine (sweetness), lactic acid (sourness), and γ-aminobutyric acid in PB-paocai, which would endow it with important flavor features. Such features could then facilitate starter screening and fermentation optimization to produce paocai-related foods with better nutritional and sensory qualities. PMID:26915389

  16. Proceedings of the international conference on incineration of hazardous, radioactive and mixed wastes

    This book discusses the following topics: Regulatory aspects of incineration; national programs: overview of U.S. hazardous waste incineration capacity; operating experience: radioactive; hazardous; institutional; safety consideration and public perception; role of research; commercial demonstration projects research and development: hazardous; radioactive and mixed, off-gas treatment and monitoring; and ash stabilization and immobilization

  17. Automated Standard Hazard Tool

    Stebler, Shane

    2014-01-01

    The current system used to generate standard hazard reports is considered cumbersome and iterative. This study defines a structure for this system's process in a clear, algorithmic way so that standard hazard reports and basic hazard analysis may be completed using a centralized, web-based computer application. To accomplish this task, a test server is used to host a prototype of the tool during development. The prototype is configured to easily integrate into NASA's current server systems with minimal alteration. Additionally, the tool is easily updated and provides NASA with a system that may grow to accommodate future requirements and possibly, different applications. Results of this project's success are outlined in positive, subjective reviews complete by payload providers and NASA Safety and Mission Assurance personnel. Ideally, this prototype will increase interest in the concept of standard hazard automation and lead to the full-scale production of a user-ready application.

  18. Developing hazardous waste programs

    Showstack, Randy

    Developing a fully operational hazardous waste regulatory system requires at least 10 to 15 years—even in countries with strong legal and bureaucratic institutions, according to a report on "The Evolution of Hazardous Waste Programs," which was funded by Resources for the Future (RFF) and the World Bank's South Asia Environment Group, and issued on June 4.The report, which compares the experiences of how four developed and four developing countries have created hazardous waste programs, indicates that hazardous waste issues usually do not become a pressing environmental issue until after countries have dealt with more direct threats to public health, such as contaminated drinking water and air pollution. The countries examined include Indonesia, Thailand, Germany, and the United States.

  19. Flood Hazard Area

    Earth Data Analysis Center, University of New Mexico — The National Flood Hazard Layer (NFHL) data incorporates all Digital Flood Insurance Rate Map(DFIRM) databases published by FEMA, and any Letters Of Map Revision...

  20. Natural Hazards Image Database

    National Oceanic and Atmospheric Administration, Department of Commerce — Photographs and other visual media provide valuable pre- and post-event data for natural hazards. Research, mitigation, and forecasting rely on visual data for...

  1. Hazards from aircraft

    The siting of nuclear power plants has created innumerable environmental concerns. Among the effects of the ''man-made environment'' one of increasing importance in recent nuclear plant siting hazards analysis has been the concern about aircraft hazards to the nuclear plant. These hazards are of concern because of the possibility that an aircraft may have a malfunction and crash either near the plant or directly into it. Such a crash could be postulated to result, because of missile and/or fire effects, in radioactive releases which would endanger the public health and safety. The majority of studies related to hazards from air traffic have been concerned with the determination of the probability associated with an aircraft striking vulnerable portions of a given plant. Other studies have focused on the structural response to such a strike. This work focuses on the problem of strike probability. 13 references

  2. Flood Hazard Boundaries

    Earth Data Analysis Center, University of New Mexico — The National Flood Hazard Layer (NFHL) data incorporates all Digital Flood Insurance Rate Map(DFIRM) databases published by FEMA, and any Letters Of Map Revision...

  3. What Are Volcano Hazards?

    ... Sheet 002-97 Revised March 2008 What Are Volcano Hazards? Volcanoes give rise to numerous geologic and ... as far as 15 miles from the volcano. Volcano Landslides A landslide or debris avalanche is a ...

  4. Probabilistic Tsunami Hazard Analysis

    Thio, H. K.; Ichinose, G. A.; Somerville, P. G.; Polet, J.

    2006-12-01

    The recent tsunami disaster caused by the 2004 Sumatra-Andaman earthquake has focused our attention to the hazard posed by large earthquakes that occur under water, in particular subduction zone earthquakes, and the tsunamis that they generate. Even though these kinds of events are rare, the very large loss of life and material destruction caused by this earthquake warrant a significant effort towards the mitigation of the tsunami hazard. For ground motion hazard, Probabilistic Seismic Hazard Analysis (PSHA) has become a standard practice in the evaluation and mitigation of seismic hazard to populations in particular with respect to structures, infrastructure and lifelines. Its ability to condense the complexities and variability of seismic activity into a manageable set of parameters greatly facilitates the design of effective seismic resistant buildings but also the planning of infrastructure projects. Probabilistic Tsunami Hazard Analysis (PTHA) achieves the same goal for hazards posed by tsunami. There are great advantages of implementing such a method to evaluate the total risk (seismic and tsunami) to coastal communities. The method that we have developed is based on the traditional PSHA and therefore completely consistent with standard seismic practice. Because of the strong dependence of tsunami wave heights on bathymetry, we use a full waveform tsunami waveform computation in lieu of attenuation relations that are common in PSHA. By pre-computing and storing the tsunami waveforms at points along the coast generated for sets of subfaults that comprise larger earthquake faults, we can efficiently synthesize tsunami waveforms for any slip distribution on those faults by summing the individual subfault tsunami waveforms (weighted by their slip). This efficiency make it feasible to use Green's function summation in lieu of attenuation relations to provide very accurate estimates of tsunami height for probabilistic calculations, where one typically computes

  5. K Basin Hazard Analysis

    This report describes the methodology used in conducting the K Basins Hazard Analysis, which provides the foundation for the K Basins Final Safety Analysis Report. This hazard analysis was performed in accordance with guidance provided by DOE-STD-3009-94, Preparation Guide for U. S. Department of Energy Nonreactor Nuclear Facility Safety Analysis Reports and implements the requirements of DOE Order 5480.23, Nuclear Safety Analysis Report

  6. K Basins Hazard Analysis

    This report describes the methodology used in conducting the K Basins Hazard Analysis, which provides the foundation for the K Basins Safety Analysis Report (HNF-SD-WM-SAR-062/Rev.4). This hazard analysis was performed in accordance with guidance provided by DOE-STD-3009-94, Preparation Guide for U. S. Department of Energy Nonreactor Nuclear Facility Safety Analysis Reports and implements the requirements of DOE Order 5480.23, Nuclear Safety Analysis Report

  7. Thunderstorm hazards flight research: Storm hazards 1980 overview

    Deal, P. L.; Keyser, G. L.; Fisher, B. D.; Crabill, N. L.

    1981-01-01

    A highly instrumented NASA F-106B aircraft, modified for the storm hazards mission and protected against direct lightning strikes, was used in conjunction with various ground based radar and lightning measurement systems to collect data during thunderstorm penetration flights. During 69 thunderstorm penetrations, there were 10 direct lightning strikes to the aircraft. No problems were encountered with any of the aircraft's systems as a result of the strikes and the research instrumentation performed as designed. Electromagnetic characteristics of nine strikes were recorded, and the results of other experiments confirm the theory that X-ray radiation and nitrous oxide gas are being produced by processes associated directly with thunderstorm electric fields and lightning discharges. A better understanding of aircraft lightning attachment mechanisms and strike zones is being accomplished by careful inspection, identification, and documentation of lightning attachment points and swept stroke paths following each strike to the aircraft.

  8. HAZARD ANALYSIS SOFTWARE

    Washington Safety Management Solutions, LLC developed web-based software to improve the efficiency and consistency of hazard identification and analysis, control selection and classification, and to standardize analysis reporting at Savannah River Site. In the new nuclear age, information technology provides methods to improve the efficiency of the documented safety analysis development process which includes hazard analysis activities. This software provides a web interface that interacts with a relational database to support analysis, record data, and to ensure reporting consistency. A team of subject matter experts participated in a series of meetings to review the associated processes and procedures for requirements and standard practices. Through these meetings, a set of software requirements were developed and compiled into a requirements traceability matrix from which software could be developed. The software was tested to ensure compliance with the requirements. Training was provided to the hazard analysis leads. Hazard analysis teams using the software have verified its operability. The software has been classified as NQA-1, Level D, as it supports the analysis team but does not perform the analysis. The software can be transported to other sites with alternate risk schemes. The software is being used to support the development of 14 hazard analyses. User responses have been positive with a number of suggestions for improvement which are being incorporated as time permits. The software has enforced a uniform implementation of the site procedures. The software has significantly improved the efficiency and standardization of the hazard analysis process

  9. Carbon Structure Hazard Control

    Yoder, Tommy; Greene, Ben; Porter, Alan

    2015-01-01

    Carbon composite structures are widely used in virtually all advanced technology industries for a multitude of applications. The high strength-to-weight ratio and resistance to aggressive service environments make them highly desirable. Automotive, aerospace, and petroleum industries extensively use, and will continue to use, this enabling technology. As a result of this broad range of use, field and test personnel are increasingly exposed to hazards associated with these structures. No single published document exists to address the hazards and make recommendations for the hazard controls required for the different exposure possibilities from damaged structures including airborne fibers, fly, and dust. The potential for personnel exposure varies depending on the application or manipulation of the structure. The effect of exposure to carbon hazards is not limited to personnel, protection of electronics and mechanical equipment must be considered as well. The various exposure opportunities defined in this document include pre-manufacturing fly and dust, the cured structure, manufacturing/machining, post-event cleanup, and post-event test and/or evaluation. Hazard control is defined as it is applicable or applied for the specific exposure opportunity. The carbon exposure hazard includes fly, dust, fiber (cured/uncured), and matrix vapor/thermal decomposition products. By using the recommendations in this document, a high level of confidence can be assured for the protection of personnel and equipment.

  10. Analysis of feed stream acid gas concentration effects on the transport properties and separation performance of polymeric membranes for natural gas sweetening: A comparison between a glassy and rubbery polymer

    Vaughn, Justin T.

    2014-09-01

    A 6FDA based polyamide-imide, 6F-PAI-1, is compared to Pebax®, a commercially available rubbery polyether/polyamide block copolymer, for the simultaneous separation of CO2 and H2S from CH4. Feed streams of 20/20/60 and 5/45/50H2S/CO2/CH4 were used to compare the effect of acid gas concentration on the separation efficiency of 6F-PAI-1 and Pebax® under industrially relevant conditions. 6F-PAI-1 showed CO2/CH4 selectivities at 850psia total feed pressure of 30 and 40 for the 20/20/60 and 5/45/50 feed streams, respectively, while selectivity for H2S/CH4 was approximately 20 for both feeds. Pebax® showed selectivities of 40 and 10 for H2S/CH4 and CO2/CH4, respectively. Both selectivities were mostly independent of acid gas concentration in the feed, an unsurprising trend considering the non-glassy nature of this material. The selectivities in 6F-PAI-1 translated to less than 6% CH4 lost in the permeate stream for both feeds, while for the 5/45/50 feed, CH4 fraction in the permeate at 850psia was less than 4%. These promising results suggest that glassy polymers possessing favorable intrinsic plasticization resistance, such as 6F-PAI-1, may be appropriate for the typical case of natural gas sweetening where CO2 concentration in the feed is higher than it is for H2S. © 2014 Elsevier B.V.

  11. Possibility of Production of Amino Acids by Impact Reaction Using a Light-Gas Gun as a Simulation of Asteroid Impacts

    Okochi, Kazuki; Mieno, Tetsu; Kondo, Kazuhiko; Hasegawa, Sunao; Kurosawa, Kosuke

    2015-06-01

    In order to investigate impact production of carbonaceous products by asteroids on Titan and other satellites and planets, simulation experiments were carried out using a 2-stage light gas gun. A small polycarbonate or metal bullet with about 6.5 km/s was injected into a pressurized target chamber filled with 1 atm of nitrogen gas, to collide with a ice + iron target or an iron target or a ice + hexane + iron target. After the impact, black soot including fine particles was deposited on the chamber wall. The soot was carefully collected and analyzed by High Performance Liquid Chromatography (HPLC), Fourier Transform Infrared Spectroscopy (FT-IR), and Laser Desorption Time-of-Flight Mass Spectrometry (LD-ToF-MS). As a result of the HPLC analysis, about 0.04-8 pmol of glycine, and a lesser amount of alanine were found in the samples when the ice + hexane + iron target was used. In case of the ice + iron target and the iron target, less amino acids were produced. The identification of the amino acids was also supported by FTIR and LD-ToF-MS analysis.

  12. Efficiency of Gas-Phase Ion Formation in Matrix-Assisted Laser Desorption Ionization with 2,5-Dihydroxybenzoic Acid as Matrix

    Numbers of matrix- and analyte-derived ions and their sum in matrix-assisted laser desorption ionization (MALDI) of a peptide were measured using 2,5-dihydroxybenzoic acid (DHB) as matrix. As for MALDI with α-cyano-4-hydroxy cinnamic acid as matrix, the sum was independent of the peptide concentration in the solid sample, or was the same as that of pure DHB. This suggested that the matrix ion was the primary ion and that the peptide ion was generated by matrix-to-peptide proton transfer. Experimental ionization efficiencies of 10-5-10-4 for peptides and 10-8-10-7 for matrices are far smaller than 10.3-10.1 for peptides and 10-5-10-3 for matrices speculated by Hillenkamp and Karas. Number of gas-phase ions generated by MALDI was unaffected by laser wavelength or pulse energy. This suggests that the main role of photo-absorption in MALDI is not in generating ions via a multi-photon process but in ablating materials in a solid sample to the gas phase

  13. Possibility of production of amino acids by impact reaction using a light-gas gun as a simulation of asteroid impacts.

    Okochi, Kazuki; Mieno, Tetsu; Kondo, Kazuhiko; Hasegawa, Sunao; Kurosawa, Kosuke

    2015-06-01

    In order to investigate impact production of carbonaceous products by asteroids on Titan and other satellites and planets, simulation experiments were carried out using a 2-stage light gas gun. A small polycarbonate or metal bullet with about 6.5 km/s was injected into a pressurized target chamber filled with 1 atm of nitrogen gas, to collide with a ice + iron target or an iron target or a ice + hexane + iron target. After the impact, black soot including fine particles was deposited on the chamber wall. The soot was carefully collected and analyzed by High Performance Liquid Chromatography (HPLC), Fourier Transform Infrared Spectroscopy (FT-IR), and Laser Desorption Time-of-Flight Mass Spectrometry (LD-ToF-MS). As a result of the HPLC analysis, about 0.04-8 pmol of glycine, and a lesser amount of alanine were found in the samples when the ice + hexane + iron target was used. In case of the ice + iron target and the iron target, less amino acids were produced. The identification of the amino acids was also supported by FTIR and LD-ToF-MS analysis. PMID:25796389

  14. Importance of blood gas measurements in perinatal asphyxia and alternatives to restore the acid base balance status to improve the newborn performance

    H. Orozco-Gregorio

    2007-01-01

    Full Text Available Prolonged or intermittent asphyxia in utero and during farrowing weakens piglets and renders them less capable of adaptation to extrauterine life. Piglets with lesser viability at birth have increased blood pCO2 and blood lactic acid concentrations and decreased blood pH. Moreover, the ability to thermoregulate during an acute cold stress is inversely related to umbilical blood lactate concentrations. Blood gas measurements and noninvasive estimations provide important information about oxygenation. The general goals of oxygen therapy in the neonate are to maintain adequate arterial PaO2 and SaO2, and to minimize cardiac work and the work of breathing. Arterial blood gas determinations of pCO2 provide the most accurate determinations of the adequacy of alveolar ventilation. Blood gases obtained in the immediate perinatal period can help assess perinatal asphyxia, but particular attention must be paid to the sampling site, the time of life, and the possible and proven diagnoses. The decision to obtain blood gases must be weighed by the individual clinician against the potential benefits. Current measures for restoring the acid base balance status in the newborn with perinatal asphyxia are discussed.

  15. Determination of Labeled Fatty Acids Content in Milk Products, Infant Formula, and Adult/Pediatric Nutritional Formula by Capillary Gas Chromatography: Collaborative Study, Final Action 2012.13.

    Golay, Pierre-Alain; Moulin, Julie

    2016-01-01

    A collaborative study was conducted on AOAC First Action Method 2012.13 "Determination of Labeled Fatty Acids Content in Milk Products and Infant Formula by Capillary Gas Chromatography," which is based on an initial International Organization for Standardization (ISO)-International Dairy Federation (IDF) New Work Item that has been moved forward to ISO 16958:2015|IDF 231:2015 in November 2015. It was decided to merge the two activities after the agreement signed between ISO and AOAC in June 2012 to develop common standards and to avoid duplicate work. The collaborative study was performed after having provided highly satisfactory single-laboratory validation results [Golay, P.A., & Dong, Y. (2015) J. AOAC Int. 98, 1679-1696] that exceeded the performance criteria defined in AOAC Standard Method Performance Requirement (SMPR(®)) 2012.011 (September 29, 2012) on 12 products selected by the AOAC Stakeholder Panel on Infant Formula (SPIFAN). After a qualification period of 1 month, 18 laboratories participated in the fatty acids analysis of 12 different samples in duplicate. Six samples were selected to meet AOAC SPIFAN requirements (i.e., infant formula and adult nutritionals in powder and liquid formats), and the other Six samples were selected to meet ISO-IDF requirements (i.e., dairy products such as milk powder, liquid milk, cream, butter, infant formula with milk, and cheese). The fatty acids were analyzed directly in all samples without preliminary fat extraction, except in one sample (cheese). Powdered samples were analyzed after dissolution (i.e., reconstitution) in water, whereas liquid samples (or extracted fat) were analyzed directly. After addition of the internal standards solution [C11:0 fatty acid methyl ester (FAME) and C13:0 triacylglycerols (TAG)] to the samples, fatty acids attached to lipids were transformed into FAMEs by direct transesterification using methanolic sodium methoxide. FAMEs were separated using highly polar capillary GLC and were

  16. Transportation of hazardous materials emergency preparedness hazards assessment

    This report documents the Emergency Preparedness Hazards Assessment (EPHA) for the Transportation of Hazardous Materials (THM) at the Department of Energy (DOE) Savannah River Site (SRS). This hazards assessment is intended to identify and analyze those transportation hazards significant enough to warrant consideration in the SRS Emergency Management Program

  17. Training hazard perception skills. [previously known as: Training hazard perception.

    2010-01-01

    Hazard perception is an essential skill in the driving task, but it is still badly developed among novice drivers. Hazard perception consists of more than perceiving hazards. It also concerns appraising the seriousness of the hazards, and knowing how to act to avert them. There are indications that

  18. Transportation of Hazardous Materials Emergency Preparedness Hazards Assessment

    This report documents the Emergency Preparedness Hazards Assessment (EPHA) for the Transportation of Hazardous Materials (THM) at the Department of Energy (DOE) Savannah River Site (SRS). This hazards assessment is intended to identify and analyze those transportation hazards significant enough to warrant consideration in the SRS Emergency Management Program

  19. Transportation of Hazardous Materials Emergency Preparedness Hazards Assessment

    Blanchard, A.

    2000-02-28

    This report documents the Emergency Preparedness Hazards Assessment (EPHA) for the Transportation of Hazardous Materials (THM) at the Department of Energy (DOE) Savannah River Site (SRS). This hazards assessment is intended to identify and analyze those transportation hazards significant enough to warrant consideration in the SRS Emergency Management Program.

  20. EFSA BIOHAZ Panel (EFSA Panel on Biological Hazards), 2014. Scientific Opinion on the evaluation of the safety and efficacy of peroxyacetic acid solutions for reduction of pathogens on poultry carcasses and meat

    Hald, Tine; Baggesen, Dorte Lau

    2014-01-01

    Studies evaluating the safety and efficacy of solutions, containing peroxyacetic acid (PAA) as the active ingredient, in mixtures with acetic acid, hydrogen peroxide, and 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP) and possibly octanoic acid and peroxyoctanoic acid, for reduction of pathogens on poultry carcasses and meat were assessed. Treatments at ambient temperature consisted of dipping in short term baths, in chiller baths or spraying. On the basis of the previous EFSA exposure scen...

  1. Modeling Phase Equilibria for Acid Gas Mixtures Using the CPA Equation of State. I. Mixtures with H2S

    Tsivintzelis, Ioannis; Kontogeorgis, Georgios; Michelsen, Michael Locht;

    2010-01-01

    The Cubic-Plus-Association (CPA) equation of state is applied to a large variety of mixtures containing H2S, which are of interest in the oil and gas industry. Binary H2S mixtures with alkanes, CO2, water, methanol, and glycols are first considered. The interactions of H2S with polar compounds (w...

  2. MINERAL CONCENTRATIONS OF FORAGE LEGUMES AND GRASSES GROWN IN ACIDIC SOIL AMENDED WITH FLUE GAS DESULFURIZATION PRODUCTS

    Considerable quantities of flue gas desulfurization products (FGDs) are generated when coal is burned for production of electricity, and these products have the potential to be reused rather than discarded. Use of FGDs as soil amendments could be important in overall management of these products, ...

  3. Influence of gas-particle partitioning on ammonia and nitric acid fluxes above a deciduous forest in the Midwestern USA

    Hansen, Kristina; Sørensen, Lise Lotte; Hornsby, Karen E.;

    diffusion denuders with detection by florescence and half-hourly flux measurements are calculated. HNO3 REA system is based on gas capture on sodium chloride (NaCl) coated denuders with subsequent analysis by ion-chromatography, and the resulting fluxes have a resolution of 3-4 hours. CO2 fluxes are...

  4. Study of disulfide reduction and alkyl chloroformate derivatization of plasma sulfur amino acids using gas chromatography–mass spectrometry

    Švagera, Z.; Hanzlíková, D.; Šimek, Petr; Hušek, Petr

    2012-01-01

    Roč. 402, č. 9 (2012), s. 2953-2963. ISSN 1618-2642 R&D Projects: GA MZd NS9755; GA ČR GAP206/10/2401; GA ČR GA203/09/2014 Institutional research plan: CEZ:AV0Z50070508 Keywords : plasma amino acids * disulfide-reducing agents * trichloroacetic acid deproteinization Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.659, year: 2012 http://www.springerlink.com/content/781wln3085q3v21r/

  5. Mapping intercellular CO2 mole fraction (Ci) in rosa rubiginosa leaves fed with abscisic acid by using chlorophyll fluorescence imaging. Significance Of ci estimated from leaf gas exchange

    Meyer; Genty

    1998-03-01

    Imaging of photochemical yield of photosystem II (PSII) computed from leaf chlorophyll fluorescence images and gas-exchange measurements were performed on Rosa rubiginosa leaflets during abscisic acid (ABA) addition. In air ABA induced a decrease of both the net CO2 assimilation (An) and the stomatal water vapor conductance (gs). After ABA treatment, imaging in transient nonphotorespiratory conditions (0.1% O2) revealed a heterogeneous decrease of PSII photochemical yield. This decline was fully reversed by a transient high CO2 concentration (7400 mol mol-1) in the leaf atmosphere. It was concluded that ABA primarily affected An by decreasing the CO2 supply at ribulose-1,5-bisphosphate carboxylase/oxygenase. Therefore, the An versus intercellular mole fraction (Ci) relationship was assumed not to be affected by ABA, and images of Ci and gs were constructed from images of PSII photochemical yield under nonphotorespiratory conditions. The distribution of gs remained unimodal following ABA treatment. A comparison of calculations of Ci from images and gas exchange in ABA-treated leaves showed that the overestimation of Ci estimated from gas exchange was only partly due to heterogeneity. This overestimation was also attributed to the cuticular transpiration, which largely affects the calculation of the leaf conductance to CO2, when leaf conductance to water is low. PMID:9501127

  6. A rapid and non-invasive method to determine toxic levels of alcohols and γ-hydroxybutyric acid in saliva samples by gas chromatography-differential mobility spectrometry.

    Criado-García, L; Ruszkiewicz, D M; Eiceman, G A; Thomas, C L P

    2016-03-01

    A polydimethylsiloxane oral sampler was used to extract methanol, ethanol, ethylene glycol, 1,3-propandiol and γ-hydroxybutyric acid from samples of human saliva obtained using a passive drool approach. The extracted compounds were recovered by thermal desorption, isolated by gas chromatography and detected with differential mobility spectrometry, operating with a programmed dispersion field. Complex signal behaviours were also observed that were consistent with hitherto unobserved fragmentation behaviours in differential mobility spectrometry. These yielded high-mobility fragments obscured within the envelope of the water-based reactant ion peak. Further, compensation field maxima shifts were also observed which were attributable to transport gas modification phenomena. Nevertheless, the responses obtained indicated that in vivo saliva sampling with thermal desorption gas chromatography may be used to provide a semi-quantitative diagnostic screen over the toxicity threshold concentration ranges of 100 mg dm(-3) to 3 g dm(-3). A candidate method suitable for use in low resource settings for the non-invasive screening of patients intoxicated by alcohols and volatile sedatives has been demonstrated. PMID:26744364

  7. Chemical process hazards analysis

    NONE

    1996-02-01

    The Office of Worker Health and Safety (EH-5) under the Assistant Secretary for the Environment, Safety and Health of the US Department (DOE) has published two handbooks for use by DOE contractors managing facilities and processes covered by the Occupational Safety and Health Administration (OSHA) Rule for Process Safety Management of Highly Hazardous Chemicals (29 CFR 1910.119), herein referred to as the PSM Rule. The PSM Rule contains an integrated set of chemical process safety management elements designed to prevent chemical releases that can lead to catastrophic fires, explosions, or toxic exposures. The purpose of the two handbooks, ``Process Safety Management for Highly Hazardous Chemicals`` and ``Chemical Process Hazards Analysis,`` is to facilitate implementation of the provisions of the PSM Rule within the DOE. The purpose of this handbook ``Chemical Process Hazards Analysis,`` is to facilitate, within the DOE, the performance of chemical process hazards analyses (PrHAs) as required under the PSM Rule. It provides basic information for the performance of PrHAs, and should not be considered a complete resource on PrHA methods. Likewise, to determine if a facility is covered by the PSM rule, the reader should refer to the handbook, ``Process Safety Management for Highly Hazardous Chemicals`` (DOE- HDBK-1101-96). Promulgation of the PSM Rule has heightened the awareness of chemical safety management issues within the DOE. This handbook is intended for use by DOE facilities and processes covered by the PSM rule to facilitate contractor implementation of the PrHA element of the PSM Rule. However, contractors whose facilities and processes not covered by the PSM Rule may also use this handbook as a basis for conducting process hazards analyses as part of their good management practices. This handbook explains the minimum requirements for PrHAs outlined in the PSM Rule. Nowhere have requirements been added beyond what is specifically required by the rule.

  8. 75 FR 63774 - Pipeline Safety: Safety of On-Shore Hazardous Liquid Pipelines

    2010-10-18

    ... implemented specific leak detection requirements in its IM rule for hazardous liquid pipelines (65 FR 75378... primarily of steel or iron. ``Standards for Direct Assessment of Gas and Hazardous Liquid Pipelines'' (70 FR...). That law, modeled on the Natural Gas Pipeline Safety Act of 1968, Public Law 90-481, delegated to...

  9. Gas phase attachment of water and methanol to Ag(I) complexes with alpha-amino acids in an ion trap mass spectrometer.

    Perera, B A; Ince, M P; Talaty, E R; Van Stipdonk, M J

    2001-01-01

    Electrospray ionization was used to generate gas phase complexes of Ag+ with selected alpha-amino acids. Following storage (isolation without collisional activation) in an ion trap mass spectrometer, the mass spectra produced from the complexes of Ag+ with alpha-amino acids such as alanine, valine and tert-leucine contained peaks consistent with the formation of water or methanol molecule adduct ions. The same adduct ions were not present, however, in the mass spectra generated from the Ag+ complexes with phenylalanine, tyrosine and tryptophan following isolation and storage under similar conditions. For those complexes that showed reactivity, the uptake of water and methanol increased with longer storage times in the ion trap. A preliminary molecular modeling study using phenylalanine demonstrated that the aromatic ring coordinates the Ag+ ion, and the interaction between the metal ion and pi-system, in part, is assumed to prohibit the binding of water or methanol during isolation in the gas phase. This conclusion is supported by a comparison of the adduct formation by the Ag+ complexes with phenylalanine, 4-fluorophenylalanine and alpha-aminocyclohexanepropionic acid. In addition, collision induced dissociation experiments involving the Ag+ complexes of phenylalanine, tyrosine and tryptophan suggest that limiting the coordination of the Ag ion by the complexing molecule (i.e. by loss of a coordinating functional group and/or change in structure due to dissociation) results in the binding of a water or methanol molecule during storage in the ion trap. Surprisingly, the bare Ag+ ion, when trapped and stored under identical experimental conditions, formed neither adduct species, suggesting that the attachment of water or methanol may be due to interactions with a molecular orbital within the Ag+/molecule complex. PMID:11312512

  10. 76 FR 16534 - Hazardous Waste Management System Identification and Listing of Hazardous Waste; Final Exclusion

    2011-03-24

    ...) from the definition of hazardous waste on a one-time basis, wastewater treatment sludge generated at... as described in the October 7, 2010 proposed rule (75 FR 62040). II. Background A. What is a... part from the treatment of wastewater in the pickle acid treatment system and, therefore,...

  11. Evidence of rich microbial communities in the subsoil of a boreal acid sulphate soil conducive to greenhouse gas emissions

    Šimek, Miloslav; Virtanen, S.; Krištůfek, Václav; Simojoki, A.; Yli-Halla, M.

    2011-01-01

    Roč. 140, 1-2 (2011), s. 113-122. ISSN 0167-8809 R&D Projects: GA ČR GA526/09/1570; GA MŠk LC06066 Institutional research plan: CEZ:AV0Z60660521 Keywords : acid sulphate soil * microorganisms * carbon Subject RIV: EH - Ecology, Behaviour Impact factor: 3.004, year: 2011

  12. Detection of monohydroxyeicosatetraenoic acids and F2-isoprostanes in microdialysis samples of human UV-irradiated skin by gas chromatography-mass spectrometry.

    Grundmann, J-U; Wiswedel, I; Hirsch, D; Gollnick, H P M

    2004-01-01

    UV irradiation of the human skin leads to induction of oxidative stress and inflammation mediated by reactive oxygen radicals, lipid peroxidation, liberation of arachidonic acid from membrane phospholipids and formation of prostaglandins and leucotrienes. We investigated "lipid mediators", such as F(2)-isoprostanes (8-iso-PGF(2alpha), 9alpha,11alpha-PGF(2alpha)) and monohydroxyeicosatetraenoic acids (HETEs) in the dermal interstitial fluid obtained by a cutaneous microdialysis technique. Defined areas on the volar forearm of 10 healthy volunteers were exposed to UVB irradiation (20-60 mJ/cm(2)). Microdialysis membranes were cutaneously inserted beneath the irradiated area. The probes were perfused with isotonic saline solution, and microdialysate samples were collected at 20-min intervals up to 4-5 h. Oxidized arachidonic acid derivatives (2-, 3-, 5-, 8-12- and 15-HETEs, 8-iso-PGF(2alpha) and 9alpha,11alpha-PGF(2alpha)) could be detected and quantified in microdialysates of normal skin in the picomole (HETEs) and femtomole (isoprostanes) range and after UVB irradiation using sensitive gas chromatography-mass spectrometry/negative ion chemical ionization. UVB irradiation enhanced the levels of 8-iso-PGF(2alpha) after 24 h significantly, whereas the HETE levels were slightly increased within shorter time intervals (3 h after UVB irradiation). Further investigations have to show whether these new findings are relevant to validate therapeutic strategies for topical and systemic UV prevention agents or for monitoring of specific therapeutic strategies in inflammatory skin disorders. PMID:14755126

  13. The California Hazards Institute

    Rundle, J. B.; Kellogg, L. H.; Turcotte, D. L.

    2006-12-01

    California's abundant resources are linked with its natural hazards. Earthquakes, landslides, wildfires, floods, tsunamis, volcanic eruptions, severe storms, fires, and droughts afflict the state regularly. These events have the potential to become great disasters, like the San Francisco earthquake and fire of 1906, that overwhelm the capacity of society to respond. At such times, the fabric of civic life is frayed, political leadership is tested, economic losses can dwarf available resources, and full recovery can take decades. A patchwork of Federal, state and local programs are in place to address individual hazards, but California lacks effective coordination to forecast, prevent, prepare for, mitigate, respond to, and recover from, the harmful effects of natural disasters. Moreover, we do not know enough about the frequency, size, time, or locations where they may strike, nor about how the natural environment and man-made structures would respond. As California's population grows and becomes more interdependent, even moderate events have the potential to trigger catastrophes. Natural hazards need not become natural disasters if they are addressed proactively and effectively, rather than reactively. The University of California, with 10 campuses distributed across the state, has world-class faculty and students engaged in research and education in all fields of direct relevance to hazards. For that reason, the UC can become a world leader in anticipating and managing natural hazards in order to prevent loss of life and property and degradation of environmental quality. The University of California, Office of the President, has therefore established a new system-wide Multicampus Research Project, the California Hazards Institute (CHI), as a mechanism to research innovative, effective solutions for California. The CHI will build on the rich intellectual capital and expertise of the Golden State to provide the best available science, knowledge and tools for

  14. IDENTIFICATION OF AIRCRAFT HAZARDS

    Aircraft hazards were determined to be potentially applicable to a repository at Yucca Mountain in the ''Monitored Geological Repository External Events Hazards Screening Analysis'' (BSC 2004, Section 6.4.1). That determination was conservatively based on limited knowledge of flight data in the area of concern and on crash data for aircraft of the type flying near Yucca Mountain. The purpose of this report is to identify specific aircraft hazards that may be applicable to a Monitored Geologic Repository (MGR) at Yucca Mountain using NUREG-0800, ''Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants'' (NRC 1987, Section 3.5.1.6), as guidance for the inclusion or exclusion of identified aircraft hazards. NUREG-0800 is being used here as a reference because some of the same considerations apply. The intended use of this report is to provide inputs for further screening and analysis of the identified aircraft hazards based on the criteria that apply to Category 1 and 2 event sequence analyses as defined in 10 CFR 63.2 (see Section 4). The scope of this technical report includes the evaluation of military, private, and commercial use of airspace in the 100-mile regional setting of the MGR at Yucca Mountain with the potential for reducing the regional setting to a more manageable size after consideration of applicable screening criteria (see Section 7)

  15. IDENTIFICATION OF AIRCRAFT HAZARDS

    K.L. Ashley

    2005-03-23

    Aircraft hazards were determined to be potentially applicable to a repository at Yucca Mountain in the ''Monitored Geological Repository External Events Hazards Screening Analysis'' (BSC 2004, Section 6.4.1). That determination was conservatively based on limited knowledge of flight data in the area of concern and on crash data for aircraft of the type flying near Yucca Mountain. The purpose of this report is to identify specific aircraft hazards that may be applicable to a Monitored Geologic Repository (MGR) at Yucca Mountain using NUREG-0800, ''Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants'' (NRC 1987, Section 3.5.1.6), as guidance for the inclusion or exclusion of identified aircraft hazards. NUREG-0800 is being used here as a reference because some of the same considerations apply. The intended use of this report is to provide inputs for further screening and analysis of the identified aircraft hazards based on the criteria that apply to Category 1 and 2 event sequence analyses as defined in 10 CFR 63.2 (see Section 4). The scope of this technical report includes the evaluation of military, private, and commercial use of airspace in the 100-mile regional setting of the MGR at Yucca Mountain with the potential for reducing the regional setting to a more manageable size after consideration of applicable screening criteria (see Section 7).

  16. Radiation and hazards

    The lecture printed in this brochure gives a complete roundup on radiation and hazards related thereto. It deals with different kinds and effects of radiation injuries as well as the relationship between dose and radiation hazard. It furthermore gives an account of today's radiation dose to inhabitants, and an evaluation of radiation hazards related thereto as compared to other hazards of modern life. This includes topical questions and problems that are also discussed in public, e.g. reviewing the data of Hiroshima and Nagasaki, radiation sensitivity of the thyroid gland, natural radiation exposure from structural materials of the building industry, and the risk of lung cancer due to inhalation of radioactive matter. The statistic survey of the Federal Home Secretary on radiation exposure from emissions of radioactive matter of nuclear facilities such as nuclear power plants, nuclear experimental plants and nuclear fuel fabrication plants in the Federal Republic of Germany gives figures on the actual radiation hazards in this country. (orig./HSCH)

  17. Identification of Aircraft Hazards

    K. Ashley

    2006-12-08

    Aircraft hazards were determined to be potentially applicable to a repository at Yucca Mountain in ''Monitored Geological Repository External Events Hazards Screening Analysis'' (BSC 2005 [DIRS 174235], Section 6.4.1). That determination was conservatively based upon limited knowledge of flight data in the area of concern and upon crash data for aircraft of the type flying near Yucca Mountain. The purpose of this report is to identify specific aircraft hazards that may be applicable to a monitored geologic repository (MGR) at Yucca Mountain, using NUREG-0800, ''Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants'' (NRC 1987 [DIRS 103124], Section 3.5.1.6), as guidance for the inclusion or exclusion of identified aircraft hazards. The intended use of this report is to provide inputs for further screening and analysis of identified aircraft hazards based upon the criteria that apply to Category 1 and Category 2 event sequence analyses as defined in 10 CFR 63.2 [DIRS 176544] (Section 4). The scope of this report includes the evaluation of military, private, and commercial use of airspace in the 100-mile regional setting of the repository at Yucca Mountain with the potential for reducing the regional setting to a more manageable size after consideration of applicable screening criteria (Section 7).

  18. Identification of Aircraft Hazards

    Aircraft hazards were determined to be potentially applicable to a repository at Yucca Mountain in ''Monitored Geological Repository External Events Hazards Screening Analysis'' (BSC 2005 [DIRS 174235], Section 6.4.1). That determination was conservatively based upon limited knowledge of flight data in the area of concern and upon crash data for aircraft of the type flying near Yucca Mountain. The purpose of this report is to identify specific aircraft hazards that may be applicable to a monitored geologic repository (MGR) at Yucca Mountain, using NUREG-0800, ''Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants'' (NRC 1987 [DIRS 103124], Section 3.5.1.6), as guidance for the inclusion or exclusion of identified aircraft hazards. The intended use of this report is to provide inputs for further screening and analysis of identified aircraft hazards based upon the criteria that apply to Category 1 and Category 2 event sequence analyses as defined in 10 CFR 63.2 [DIRS 176544] (Section 4). The scope of this report includes the evaluation of military, private, and commercial use of airspace in the 100-mile regional setting of the repository at Yucca Mountain with the potential for reducing the regional setting to a more manageable size after consideration of applicable screening criteria (Section 7)

  19. Natural Hazards, Second Edition

    Rouhban, Badaoui

    Natural disaster loss is on the rise, and the vulnerability of the human and physical environment to the violent forces of nature is increasing. In many parts of the world, disasters caused by natural hazards such as earthquakes, floods, landslides, drought, wildfires, intense windstorms, tsunami, and volcanic eruptions have caused the loss of human lives, injury, homelessness, and the destruction of economic and social infrastructure. Over the last few years, there has been an increase in the occurrence, severity, and intensity of disasters, culminating with the devastating tsunami of 26 December 2004 in South East Asia.Natural hazards are often unexpected or uncontrollable natural events of varying magnitude. Understanding their mechanisms and assessing their distribution in time and space are necessary for refining risk mitigation measures. This second edition of Natural Hazards, (following a first edition published in 1991 by Cambridge University Press), written by Edward Bryant, associate dean of science at Wollongong University, Australia, grapples with this crucial issue, aspects of hazard prediction, and other issues. The book presents a comprehensive analysis of different categories of hazards of climatic and geological origin.

  20. The perception of hazards

    The fourth chapter deals with the profusion of factors determining the differing assessment of hazards by our society. Subjective factors influencing risk perception comprise, among others, general knowledge and recognition of a hazard; the degree of voluntariness when taking the risk and its influencibility; the problem of large scale accidents; immediate and delayed results. Next to the objective and the subjective risks, the individual and the social or collective risks are assessed differently. The author dicusses in detail recent investigations into and study methods for the determination of risk perception, while eliminating systematic trends from subjective perception since common assessments are shared by whole groups of individuals time and again which allow a better understanding of today's handling of hazards. (HSCH)

  1. The quantification of hazards

    The seventh chapter deals in detail with the means and methods allowing to quantify the objective dimension and scope of a hazard in concrete situations. Source and type of possible damage and exposure path determine the detection and perception of hazards. Risk assessment requires the determination of the dose-effect relationship of the hazard situation and of the dimension and the probability of the damage. Risk assessments are exemplified: influenza epidemic; accidents in a nuclear power plant; the risk for the population emanating from normal nuclear power plant operation. The author concludes that subjective elements inevitably enter into any risk assessment - though to a varying extent - and, hence, that objectivity is but relative. (HSCH)

  2. Moral Hazard in Pediatrics.

    Brunnquell, Donald; Michaelson, Christopher M

    2016-07-01

    "Moral hazard" is a term familiar in economics and business ethics that illuminates why rational parties sometimes choose decisions with bad moral outcomes without necessarily intending to behave selfishly or immorally. The term is not generally used in medical ethics. Decision makers such as parents and physicians generally do not use the concept or the word in evaluating ethical dilemmas. They may not even be aware of the precise nature of the moral hazard problem they are experiencing, beyond a general concern for the patient's seemingly excessive burden. This article brings the language and logic of moral hazard to pediatrics. The concept reminds us that decision makers in this context are often not the primary party affected by their decisions. It appraises the full scope of risk at issue when decision makers decide on behalf of others and leads us to separate, respect, and prioritize the interests of affected parties. PMID:27292845

  3. Hazard Communication Standard

    The current rate of technological advances has brought with it an overwhelming increase in the usage of chemicals in the workplace and in the home. Coupled to this increase has been a heightened awareness in the potential for acute and chronic injuries attributable to chemical insults. The Hazard Communication Standard has been introduced with the desired goal of reducing workplace exposures to hazardous substances and thereby achieving a corresponding reduction in adverse health effects. It was created and proclaimed by the US Department of Labor and regulated by the Occupational Safety and Health Administration. 1 tab

  4. Onsite transportation hazards assessment

    This report documents the emergency preparedness Hazards Assessment for the onsite transportation of hazardous material at the Hanford Site. The assessment is required by US Department of Energy (DOE) Order 5500.3A and provides the technical basis for the emergency classification and response procedures. A distinction is made between onsite for the purpose of emergency preparedness and onsite for the purpose of applying US Department of Transportation (DOT) regulations. Onsite for the purpose of emergency preparedness is considered to be within the physical boundary of the entire Hanford Site. Onsite for the purpose of applying DOT regulations is north of the Wye Barricade

  5. Household hazardous waste

    Fjelsted, Lotte; Christensen, Thomas Højlund

    2007-01-01

    .) comprised 15-25% and foreign items comprised 10-20%. Water-based paint was the dominant part of the paint waste. The chemical composition of the paint waste and the paint-like waste was characterized by an analysis of 27 substances in seven waste fractions. The content of critical substances was tow and the...... incinerated. Allowing household paint waste to be collected with ordinary household waste is expected to reduce the cost of handling household hazardous waste, since paint waste in Denmark comprises the major fraction of household hazardous waste....

  6. Hazards in the Manufacture of RDX and HMX

    C. P. Achuthan

    1983-01-01

    Full Text Available Manufacture of cyclotrimethylenetrinitramine (RDX and cyclotetramethylenetetranitramine (HMX by the modified Bachmann process involves the nitrolysis of hexamine in glacial acetic acid with a solution of ammonium nitratein nitric acid, in the presence of excess of acetic anhydride. Fire, explosion and toxic hazards during the manfacture of these explosives are reviewed and discussed.

  7. Pressure Build-up and Decay in Acid Gas Injection Operations in Reefs in the Zama Field, Canada, and Implications for CO2 Storage

    The objective of this paper is to examine reasons for pressure rise in the Zama X2X pool in northwestern Alberta, Canada, that was used for acid gas disposal, and whether subsequent pressure decay was a result of pressure dissipation into a larger aquifer. The Zama X2X pool, approximately 1 km2 in size, is connected to four other nearby pools through a common underlying aquifer. Pressure analysis for all the pools indicates that they are in good hydraulic communication. Initial pressure in the Zama X2X pool was approximately 15 MPa. Pressure declined first during oil production, stabilizing at around 10 MPa in the early 1970's, after which started to increase such that it reached 26 MPa in 1986. Subsequently, pressure declined reaching 22 MPa by 1995 just prior to starting injection of acid gas (80% CO2 and 20% H2S). The operator injected acid gas at lower rates and wellhead pressures than those licensed by the regulatory agency. Despite significant production of water and hydrocarbons, the pressure in the Zama X2X pool continued to be higher than the initial reservoir pressure by more than 5 MPa, such that disposal operations were suspended in late 1998. Oil production continued all this time until 2002. Numerical simulations using CMG-IMEM and corresponding sensitivity studies reported in this paper show that disposal of more than 1 million m3 of water between 1970 and 1988 and again in 1992-1993 in the adjacent Zama YY pool, which is in good hydrodynamic communication with the Zama X2X pool through the aquifer below the oil column, is the main reason for the high pressures observed in the Zama X2X pool. Sensitivity studies indicate that pressure decay in the X2X pool was due to fluid production. The study indicates that while pressure rise has been caused by hydraulic communication between the X2X and YY pools through the common aquifer, the aquifer was not of large volume to allow dissipation of the pressure. In addition to the case study, the implications of

  8. Separation and determination of seleno amino acids using gas chromatography hyphenated with inductively coupled plasma mass spectrometry after hollow fiber liquid phase microextraction.

    Duan, Jiankun; Hu, Bin

    2009-05-01

    A new derivatization-extraction method for preconcentration of seleno amino acids using hollow fiber liquid phase microextraction (HF-LPME) was developed for the separation and determination of seleno amino acids in biological samples by gas chromatography-inductively coupled plasma mass spectrometry (GC-ICP-MS). Derivatization was performed with ethyl chloroformate (ECF) to improve the volatility of seleno amino acids. Parameters influencing microextraction, including extraction solvent, pH of sample solution, extraction time, stirring speed, and inorganic salt concentration have been investigated. Under the optimal conditions, the limits of detection (LODs) obtained for Se-methyl-selenocysteine (SeMeCys), selenomethionine (SeMet), and selenoethionine (SeEth) were 23, 15, and 11 ng Se l(-1), respectively. The relative standard deviations (RSDs) were 14.6%, 16.4%, and 19.4% for SeMeCys, SeMet, and SeEth (c = 1.0 ng ml(-1), n = 7), respectively, and the RSDs for SeMeCys, SeMet could be improved obviously if SeEth was utilized as the internal standard. The proposed method was applied for the determination of seleno amino acids in extracts of garlic, cabbage, and mushroom samples, and the recoveries for the spiked samples were in the range of 96.8-108% and 93.4-115% with and without the use of SeEth as internal standard. The developed method was also applied to the analysis of SeMet in a certified reference material of SELM-1 yeast and the determined value is in good agreement with the certified value. PMID:19053158

  9. Iodine retention from process gas and exhaust air in dissolving aluminium-clad fuel elements in nitric acid

    In the 99Mo Production Facility Rossendorf (AMOR) aluminium-clad fuel elements irradiated for about 200 h in the Rossendorf Research Reactor are chemically reprocessed after a cooling time of 48 h. The iodine isotopes produced together with a number of the other fission products have to be separated from the solution gas because of their radiotoxicity, volatility, and amount. Although iodine is retained in the facility, the existing exhaust air system was completed by a specific filter system in order to prevent any iodine releases

  10. An electron conductive polymer, poly-aniline, in gas separation: optimisation of transport properties by alternated acid-base treatment

    The objective of this research thesis is to study the variation of gas permeation properties of poly-aniline during a doping/de-doping/re-doping cycle, and to study the evolution of the separation power of this polymer. Scanning electronic microscopy is used to study the microstructure and more particularly how the doping agent is distributed within the polymer. Permeabilities, diffusion coefficients, sorption solubilities and interaction energies are measured by using coupled permeation and micro-gravimetry-calorimetry methods. A range of gases (H2, O2, CO2, N2, CH4) is analysed

  11. Hazard management at the workplace

    Failure to ensure health and safety environment at workplace will cause an accident involving loss to the time, human resource, finance and for the worse case effect the moral value of an organization. If we go through to the cause of the accident, it is impossible to have a totally safety workplace. It is because every process in work activities has it own hazard elements. The purpose of this paper is to discuss the best action to prevent from the hazard with a comprehensive and effectiveness hazard management. Hazard management is the one of the pro-active hazard control. With this we manage to identify and evaluate the hazard and control the hazard risk. Therefore, hazard management should be screened constantly and continuously to make sure work hazard always in control. (Author)

  12. 78 FR 58604 - Safety Advisory: Unauthorized Marking of Compressed Gas Cylinders

    2013-09-24

    ... Gas Cylinders AGENCY: Pipeline and Hazardous Materials Safety Administration (PHMSA), DOT. ACTION... unauthorized marking of high pressure compressed gas cylinders by Beauchesne Fire Equipment located at 21... and special permit cylinders as requalified in accordance with the Hazardous Materials...

  13. Modelling phase equilibria for acid gas mixtures using the CPA equation of state. Part V: Multicomponent mixtures containing CO2 and alcohols

    Tsivintzelis, Ioannis; Kontogeorgis, Georgios M.

    2015-01-01

    of studies [Tsivintzelis et al. Fluid Phase Equilib. 306 (2011) 38-56, J. Chem. Eng. Data 59 (2014) 2955-2972, Fluid Phase Equilib. 397 (2015) 1-17], reveals that the best approaches are those where the cross-association (solvation) of CO2 with alcohols and water is explicitly accounted for or......The Cubic plus association (CPA) equation of state has been previously applied to a variety of binary systems containing CO2 with alkanes, water, alcohols and glycols as well as a few multicomponent mixtures (with triethylene glycol, water and methane). In this study, we evaluate the performance of...... CPA for ternary and multicomponent CO2 mixtures containing alcohols (methanol, ethanol or propanol) water and hydrocarbons. This work belongs to a series of studies aiming to arrive in a single "engineering approach" for applying CPA to acid gas mixtures, without introducing significant changes to the...

  14. Modeling Phase Equilibria for Acid Gas Mixtures using the Cubic-Plus-Association Equation of State. 3. Applications Relevant to Liquid or Supercritical CO2 Transport

    Tsivintzelis, Ioannis; Ali, Shahid; Kontogeorgis, Georgios

    2014-01-01

    density data for both CO2 and CO2–water and for vapor–liquid equilibrium for mixtures of CO2 with various compounds present in transport systems. In all of these cases we consider various possibilities for modeling CO2 (inert, self-associating using two-, three-, and four sites) and the possibility of......The CPA (cubic-plus-association) equation of state is applied in this work to a wide range of systems of relevance to CO2 transport. Both phase equilibria and densities over extensive temperature and pressure ranges are considered. More specifically in this study we first evaluate CPA against...... applying CPA to acid gas mixtures. The overall conclusion is that CPA performs satisfactorily; the model in most cases correlates well binary data and predicts with good accuracy multicomponent vapor–liquid equilibria. Among the various approaches investigated, the best ones are when cross association of...

  15. New evidences on efficacy of boronic acid-based derivatization method to identify sugars in plant material by gas chromatography-mass spectrometry.

    Faraco, Marianna; Fico, Daniela; Pennetta, Antonio; De Benedetto, Giuseppe E

    2016-10-01

    This work presents an analytical procedure based on gas chromatography-mass spectrometry which allows the determination of aldoses (glucose, mannose, galactose, arabinose, xylose, fucose, rhamnose) and chetoses (fructose) in plant material. One peak for each target carbohydrate was obtained by using an efficient derivatization employing methylboronic acid and acetic anhydride sequentially, whereas the baseline separation of the analytes was accomplished using an ionic liquid capillary column. First, the proposed method was optimized and validated. Successively, it was applied to identify the carbohydrates present in plant material. Finally, the procedure was successfully applied to samples from a XVII century painting, thus highlighting the occurrence of starch glue and fruit tree gum as polysaccharide materials. PMID:27474277

  16. Overconfidence and Moral Hazard

    de la Rosa, Leonidas Enrique

    2011-01-01

    In this paper, I study the effects of overconfidence on incentive contracts in a moral-hazard framework. Agent overconfidence can have conflicting effects on the equilibrium contract. On the one hand, an optimistic or overconfident agent disproportionately values success-contingent payments, and...

  17. SCI Hazard Report Methodology

    Mitchell, Michael S.

    2010-01-01

    This slide presentation reviews the methodology in creating a Source Control Item (SCI) Hazard Report (HR). The SCI HR provides a system safety risk assessment for the following Ares I Upper Stage Production Contract (USPC) components (1) Pyro Separation Systems (2) Main Propulsion System (3) Reaction and Roll Control Systems (4) Thrust Vector Control System and (5) Ullage Settling Motor System components.

  18. Hazardous Wastes from Homes.

    Lord, John

    The management of waste materials has become more complex with the increase in human population and the development of new substances. This illustrated booklet traces the history of waste management and provides guidelines for individuals and communities in disposing of certain hazardous wastes safely. It addresses such topics as: (1) how people…

  19. Overconfidence and Moral Hazard

    de la Rosa, Leonidas Enrique

    In this paper, I study the effects of overconfidence on incentive contracts in a moral-hazard framework in which principal and agent knowingly hold asymmetric beliefs regarding the probability of success of their enterprise. Agent overconfidence can have conflicting effects on the equilibrium con...

  20. Hazardous industrial waste management

    The appropriate managing of hazardous wastes is a problem little dealed in the wastes management in the country. A search of available information was made about the generation and handling to internal and external level of the hazardous wastes by national industries. It was worked with eleven companies of different types of industrial activities for, by means of a questionnaire, interviews and visits, to determine the degree of integral and suitable handling of the wastes that they generate. It was concluded that exist only some isolated reports on the generation of hazardous industrial wastes and handling. The total quantity of wastes generated in the country was impossible to establish. The companies consulted were deficient in all stages of the handling of their wastes: generation, accumulation and storage, transport, treatment and final disposition. The lack of knowledge of the legislation and of the appropriate managing of the wastes is showed as the principal cause of the poor management of the residues. The lack of state or private entities entrusted to give services of storage, transport, treatment and final disposition of hazardous wastes in the country was evident. (author)

  1. Health Care Wide Hazards

    ... Other Hazards (Lack of) PPE Slips/Trips/Falls Stress Tuberculosis Universal Precautions Workplace Violence Use of Medical Lasers Health Effects Use ... Needlesticks Noise Mercury Inappropriate PPE Slips/Trips/Falls ... of Universal Precautions Workplace Violence For more information, see Other Healthcare Wide ...

  2. Hazardous solvent substitution

    Eliminating hazardous solvents is good for the environment, worker safety, and the bottom line. However, even though we are motivated to find replacements, the big question is 'What can we use as replacements for hazardous solvents?'You, too, can find replacements for your hazardous solvents. All you have to do is search for them. Search through the vendor literature of hundreds of companies with thousands of products. Ponder the associated material safety data sheets, assuming of course that you can obtain them and, having obtained them, that you can read them. You will want to search the trade magazines and other sources for product reviews. You will want to talk to users about how well the product actually works. You may also want to check US Environmental Protection Agency (EPA) and other government reports for toxicity and other safety information. And, of course, you will want to compare the product's constituent chemicals with the many hazardous constituency lists to ensure the safe and legal use of the product in your workplace

  3. A novel method to measure isotopic labeled gas-phase nitrous acid (HO15NO) in biogeochemical studies

    Wu, Dianming; Kampf, Christopher; Pöschl, Ulrich; Oswald, Robert; Cui, Junfang; Ermel, Michael; Hu, Chunsheng; Trebs, Ivonne; Sörgel, Matthias

    2014-05-01

    We developed a new method (gas-phase stripping-derivatization coupled to LC-MS) to measure the 15N atom percent excess (APE) of HONO in the gas-phase. Gaseous HONO is quantitatively collected and transferred to an azo dye by the well-known Griess reaction in the Long Path Absorption Photometer (LOPAP). The reaction solutions containing the dye are collected at the outflow of the LOPAP, purified by solid-phase extraction and analyzed using high performance liquid chromatography coupled to mass spectrometry (HPLC-MS). The unlabeled azo dye (C18H19O2N5S) with a monoisotopic molecular mass of 369.41 g mol-1 can be detected as its protonated molecular ion ([M+H+], M) by HPLC-MS at a retention time of 2.8 min. Due to the natural isotope distribution M + 0, M + 1, M + 2, and M + 3 ions were considered for the calculation of the 15N APE. The optimal working range was found to be between 20 and 50% for the 15N/14N ratio. The optimum pH and solvents for extraction by SPE and potential interferences are discussed. The method has been applied for the measurement of HO15NO emissions from soil in a dynamic chamber with and without spiking 15N labeled urea. Our results confirm biogenic HONO emissions from soil as HO15NO was measured after addition of 15N urea.

  4. Dust Hazard Management in the Outer Solar System

    Seal, David A.

    2012-01-01

    Most robotic missions to the outer solar system must grapple with the hazards posed by the dusty rings of the gas giants. Early assessments of these hazards led simply to ring avoidance due to insufficient data and high uncertainties on the dust population present in such rings. Recent approaches, principal among them the Cassini dust hazard management strategy, provide useful results from detailed modeling of spacecraft vulnerabilities and dust hazard regions, which along with the range of mission trajectories are used to to assess the risks posed by each passage through a zone of potential hazard. This paper shows the general approach used to implement the analysis for Cassini, with recommendations for future outer planet missions.

  5. A field-deployable, chemical ionization time-of-flight mass spectrometer: application to the measurement of gas-phase organic and inorganic acids

    T. H. Bertram

    2011-03-01

    Full Text Available We report a new field-deployable chemical ionization time-of-flight mass spectrometer (CI-TOFMS for the direct measurement of trace gases in the atmosphere. We apply the technique to the measurement of gas-phase inorganic and organic acids via negative-ion proton transfer, using acetate as the reagent ion. A novel high pressure interface, incorporating two RF-only quadrupoles is used to efficiently focus ions through four stages of differential pumping before analysis with a compact TOFMS. The high ion-duty cycle (>20% of the TOFMS, coupled to efficient production and transmission of ions in the high pressure interface results in a highly sensitive (>300 ions s−1 pptv−1 instrument capable of the fast measurement of atmospheric gases at trace levels. We demonstrate the efficient transfer and detection of both bare ions and ion-molecule clusters, and characterize the instrument during field measurements aboard the R/V Atlantis as part of the CalNex campaign during the spring of 2010. The in-field short-term precision is better than 5% at 1 pptv (pL/L, for 1-second averages. The detection limit (3σ, 1-second averages of the current version of the CI-TOFMS, as applied to the in situ detection of gas-phase acids, is limited by the magnitude and variability in the background determination and was determined to be 4 pptv.

  6. Gas phase reactions of uranyl with α-hydroxyisobutyric acid using electrospray ionization mass spectrometry and density functional theory

    Electrospray ionization mass spectrometry (ESI-MS) technique was used to find out the type of species of uranyl with a-hydroxyisobutyric acid in positive and negative ion modes. It was found that the singly charged monomeric and doubly charged dimeric species were present in soft ionization conditions. The molecular level understanding on the structures and energetics were investigated using density functional theory based calculations. It was found that ML3, the most intense species observed in ESI-MS were energetically more favorable as compared to ML1 and ML2. (author)

  7. Tank farms hazards assessment

    Hanford contractors are writing new facility specific emergency procedures in response to new and revised US Department of Energy (DOE) Orders on emergency preparedness. Emergency procedures are required for each Hanford facility that has the potential to exceed the criteria for the lowest level emergency, an Alert. The set includes: (1) a facility specific procedure on Recognition and Classification of Emergencies, (2) area procedures on Initial Emergency Response and, (3) an area procedure on Protective Action Guidance. The first steps in developing these procedures are to identify the hazards at each facility, identify the conditions that could release the hazardous material, and calculate the consequences of the releases. These steps are called a Hazards Assessment. The final product is a document that is similar in some respects to a Safety Analysis Report (SAR). The document could br produced in a month for a simple facility but could take much longer for a complex facility. Hanford has both types of facilities. A strategy has been adopted to permit completion of the first version of the new emergency procedures before all the facility hazards Assessments are complete. The procedures will initially be based on input from a task group for each facility. This strategy will but improved emergency procedures in place sooner and therefore enhance Hanford emergency preparedness. The purpose of this document is to summarize the applicable information contained within the Waste Tank Facility ''Interim Safety Basis Document, WHC-SD-WM-ISB-001'' as a resource, since the SARs covering Waste Tank Operations are not current in all cases. This hazards assessment serves to collect, organize, document and present the information utilized during the determination process

  8. Seismic hazard assessment for Adria

    K. Makropoulos

    1999-06-01

    Full Text Available The Adriatic region was chosen as one of the test areas in the GSHAP program and, consequently, its seismic hazard was computed. The standard hazard map chosen by GSHAP represents PGA with a 475-year return period. Some other parameters, as the spectral acceleration and the uniform hazard response spectra for the main Adriatic towns, have been computed for a better representation of the regional hazard. The most hazardous area remains identified in the Cephalonia zone, where strong earthquakes frequently occur. The Southern Apennines are characterised by a slightly lower hazard, while the Adriatic Sea itself, the Poplain and the Apulian peninsula are almost aseismic.

  9. Hazardous Material Storage Facilities and Sites - Commercial Hazardous Waste Operations

    NSGIC GIS Inventory (aka Ramona) — A Commercial Hazardous Waste Operation is a DEP primary facility type related to the Waste Management Hazardous Waste Program. The sub-facility types related to...

  10. A gas chromatography-mass spectrometry method for the determination of delta-aminolevulinic acid in plant leaves.

    Hijaz, Faraj; Killiny, Nabil

    2016-05-20

    Delta-aminolevulinic (δ-ALA) acid is an important intermediate for tetrapyrroles biosynthesis and it has recently received great attention in plant physiology and human toxicology. However, the colorimetric method which is the most common method for determination of δ-ALA is time consuming and is not specific. In this study, a method for determination of δ-ALA in plant tissues was developed based on the trimethylsilyl (TMS) derivative of the pyrrole formed from the reaction of δ-ALA with ethyl acetoacetate via Knorr condensation. The δ-ALA in the HCl extract was reacted with ethyl acetoacetate to form a pyrrole. Then, the pyrrole compound was extracted using ethyl acetate and the solvent was evaporated to dryness. The dried sample was derivatized to its TMS ester and analyzed using GC-MS. The concentration of δ-ALA in citrus leaves incubated with levulinic acid was also determined by the conventional colorimetric method. The linear range was 10-200ppm in the full scan mode and 0.1-20ppm in the selected ion monitoring (SIM). The limit of detection was 6ppm in the full scan and 0.05ppm in SIM mode, representing a four-fold increase in sensitivity compared to the colorimetric method. The GC-MS method developed in this study is simple, accurate, sensitive, and could also be used to measure δ-ALA in other biological samples. PMID:27106399

  11. A rapid and sensitive assay of perfluorocarboxylic acids in aqueous matrices by headspace solid phase microextraction-gas chromatography-triple quadrupole mass spectrometry.

    Monteleone, Marcello; Naccarato, Attilio; Sindona, Giovanni; Tagarelli, Antonio

    2012-08-17

    The work aims at developing a rapid and sensitive method for the quantification of perfluorocarboxylic acids in aqueous matrices. The proposed analytical approach is based on the use of solid phase microextraction in headspace mode after a fast derivatization of the carboxylate function by propylchloroformate/propanol mixture. Several fibers were evaluated and the optimization of the parameters affecting the SPME process was carried out using a central composite design. The optimum working conditions in terms of response values were achieved by performing analysis with CAR/PDMS fiber at room temperature, without addition of NaCl, with a sample volume of 6 ml and an extraction time of 10 min. Assay of PFCAs was performed by using a gas chromatography-triple quadrupole mass spectrometry (GC-QqQ MS) system in negative chemical ionization mode with ammonia as reagent gas. An overall evaluation of all analytical parameters shows that the proposed method provides satisfactory results. In particular, the observed accuracies, ranging from 84.4% to 116.8%, and the RSD values in the range 0.4% and 14.5% confirm the effectiveness of the developed protocol in the assay of PFCAs content in aqueous matrices. Moreover, LOD and LOQ values ranging from 0.08 to 6.6 ng l(-1) and from 0.17 to 14.3 ng l(-1), respectively, can be considered very satisfactory. None of the compounds were detected in six samples of river collected in Calabria. PMID:22762954

  12. Compressed Gas Safety for Experimental Fusion Facilities

    Lee C. Cadwallader

    2004-09-01

    Experimental fusion facilities present a variety of hazards to the operators and staff. There are unique or specialized hazards, including magnetic fields, cryogens, radio frequency emissions, and vacuum reservoirs. There are also more general industrial hazards, such as a wide variety of electrical power, pressurized air, and cooling water systems in use, there are crane and hoist loads, working at height, and handling compressed gas cylinders. This paper outlines the projectile hazard assoicated with compressed gas cylinders and mthods of treatment to provide for compressed gas safety. This information should be of interest to personnel at both magnetic and inertial fusion experiments.

  13. Hazard perception in traffic. [previously knows as: Hazard perception.

    2008-01-01

    Hazard perception is an essential part of the driving task. There are clear indications that insufficient skills in perceiving hazards play an important role in the occurrence of crashes, especially those involving novice drivers. Proper hazard perception not only consists of scanning and perceiving a hazard in time, but also correctly appraising the seriousness of it and knowing what to do to avert the danger. This not only demands situation awareness, but also self-assessment. There are var...

  14. Acid-yield measurements of the gas-phase ozonolysis of ethene as a function of humidity using Chemical Ionisation Mass Spectrometry (CIMS

    K. E. Leather

    2012-01-01

    Full Text Available Gas-phase ethene ozonolysis experiments were conducted at room temperature to determine formic acid yields as a function of relative humidity (RH using the integrated EXTreme RAnge chamber-Chemical Ionisation Mass Spectrometry technique, employing a CH3I ionisation scheme. RHs studied were <1, 11, 21, 27, 30 % and formic acid yields of (0.07±0.01 and (0.41±0.07 were determined at <1 % RH and 30 % RH respectively, showing a strong water dependence. It has been possible to estimate the ratio of the rate coefficient for the reaction of the Criegee biradical, CH2OO with water compared with decomposition. This analysis suggests that the rate of reaction with water ranges between 1×10−12–1×10−15 cm3 molecule−1 s−1 and will therefore dominate its loss with respect to bimolecular processes in the atmosphere. Global model integrations suggest that this reaction between CH2OO and water may dominate the production of HC(OOH in the atmosphere.

  15. Hollow fiber liquid-phase microextraction coupled with gas chromatography-flame ionization detection for the profiling of fatty acids in vegetable oils.

    Siang, Gan Hui; Makahleh, Ahmad; Saad, Bahruddin; Lim, Boey Peng

    2010-12-24

    The development of a two phase hollow fiber liquid-phase microextraction technique, followed by gas-chromatography-flame ionization detection (GC-FID) for the profiling of the fatty acids (FAs) (lauric, myristic, palmitic, stearic, palmitoleic, oleic, linoleic, linolenic and arachidic) in vegetable oils is described. Heptadecanoic acid methyl ester was used as the internal standard. The FAs were transesterified to their corresponding methyl esters prior to the extraction. Extraction parameters such as type of extracting solvent, temperature, extraction time, stirring speed and salt addition were studied and optimized. Recommended conditions were extraction solvent, n-tridecane; extraction time, 35 min; extraction temperature, ambient; without addition of salt. Enrichment factors varying from 37 to 115 were achieved. Calibration curves for the nine FAs were well correlated (r(2)>0.994) within the range of 10-5000 μg L(-1). The limit of detection (signal:noise, 3) was 4.73-13.21 ng L(-1). The method was successfully applied to the profiling of the FAs in palm oils (crude, olein, kernel, and carotino cooking oil) and other vegetable oils (soybean, olive, coconut, rice bran and pumpkin). The encouraging enrichments achieved offer an interesting option for the profiling of the minor and major FAs in palm and other vegetable oils. PMID:21081239

  16. Determination of phosphoric acid triesters in human plasma using solid-phase microextraction and gas chromatography coupled to inductively coupled plasma mass spectrometry.

    Shah, Monika; Meija, Juris; Cabovska, Baiba; Caruso, Joseph A

    2006-01-27

    A simple and sensitive method for determination of phosphoric acid triesters at trace levels in human plasma sample is described. In this work, solid-phase microextraction (SPME) is employed as a sample preparation procedure for extraction and pre-concentration of alkyl and aryl phosphates followed by gas chromatography coupled to inductively coupled plasma mass spectrometry (GC-ICP-MS) for phosphorus-specific and very sensitive determination of these compounds in human plasma. The detection limits from blood plasma were 50 ngL(-1) (tripropyl phosphate), 17 ngL(-1) (tributyl phosphate), 240 ngL(-1) (tris(2-chloroethyl) phosphate) and 24 ngL(-1) (triphenyl phosphate). Sample preparation involves plasma deproteinization followed by direct immersion SPME with 65 microm poly(dimethylsiloxane/divinylbenzene) fiber. Extraction was performed at 40 degrees C for 30 min and at pH 7.0 in 10 mM sodium carbonate buffer. The reported method, to our knowledge, describes the first application of SPME with element-specific detection for analysis of phosphoric acid esters. Application of the method to the plasma samples, previously stored in poly(vinyl chloride) plasma bags revealed the presence of triphenyl phosphate, which was further confirmed by SPME GC time-of-flight high-resolution mass spectrometry. PMID:16337211

  17. Nanoscale-supported heteropoly acid as a new fiber coating for solid-phase microextraction coupled with gas chromatography-mass spectrometry.

    Abolghasemi, Mir Mahdi; Hassani, Sona; Rafiee, Ezzat; Yousefi, Vahid

    2015-02-13

    In the present study, 12-tungstophosphoric (PW) acid as heteropoly acid, supported on silica-coated γ-Fe2O3 nanoparticles (NPs), was used as a new fiber coating for solid-phase microextraction (SPME). The γ-Fe2O3@SiO2-PW nanocomposite with high surface area was synthesized and characterized by SEM and FT-IR. The prepared nanocomposite was immobilized on a stainless steel wire for fabrication of the SPME fiber. The fiber was evaluated for the extraction of some phenolic compounds (PCs) from water sample in combination with gas chromatography-mass spectrometry (GC-MS). A one-at-a-time optimization strategy was applied for optimizing the important extraction parameters such as extraction temperature, extraction time, ionic strength, stirring rate, pH, and desorption temperature and time. In optimum conditions, the repeatability for one fiber (n=3), expressed as relative standard deviation (R.S.D. %), was between 4.8% and 9.6% for the test compounds. The detection limits for the studied compounds were between 0.004 and 0.05 pg mL(-1). The developed method offers the advantage of being simple to use, with shorter analysis time, lower cost of equipment, thermal stability of fiber and high relative recovery in comparison to conventional methods of analysis. PMID:25618361

  18. Hazard perception in traffic. [previously knows as: Hazard perception.

    2008-01-01

    Hazard perception is an essential part of the driving task. There are clear indications that insufficient skills in perceiving hazards play an important role in the occurrence of crashes, especially those involving novice drivers. Proper hazard perception not only consists of scanning and perceiving

  19. Characterization of radioactive hazardous waste

    The characterization of radioactive hazardous waste, also known as transuranic 'mixed waste' has to be completed before it can be classified for proper treatment (incinerator, mechanical compaction or thermal treatment), packing, and transport. The characterization of the TRU mixed waste is not only complex process but rather an expensive undertaking. The process knowledge is the basic foundation of characterization. It is the documented knowledge of processes and materials that generated the waste. The transuranic waste Quality Assurance Program Plan (QAPP) defines the Data Quality Objectives (DQO's) and provides the scope of analytical parameters and methods required to accurately characterize the radioactive mixed waste. Based on the historical data and process knowledge a sampling and analysis plan can be developed to characterize the radioactive hazardous waste. Based on the characterization, an assessment of the regulatory status can be made before the waste could be accepted for disposal at the WIPP facility. The Waste Acceptance Criteria (WAC) developed by WIPP defines the parameters for receiving and final disposal of the TRU waste. The sets of criteria, such as: heat generated, fissile gram equivalent (FGE), plutonium-equivalent (PE) curies, and specifications of a dose rate have to be met before the waste is accepted for deep geological disposal. The characterization of radioactive waste becomes even more complex due to the presence of iron base metals/alloys, aluminum base metals/alloys, organic, chelating agents that are mixed with plastic, rubber, cellulose, soils and cement. Some of the modern characterization technologies that are under development and currently used for TRU mixed wastes are: nondestructive examination, nondestructive assay, headspace gas analysis, and drum coring for Resources Conservation Recovery Act (RCRA) sampling. (author)

  20. Comparison and validation of 2 analytical methods for the determination of free fatty acids in dairy products by gas chromatography with flame ionization detection.

    Mannion, David T; Furey, Ambrose; Kilcawley, Kieran N

    2016-07-01

    Accurate quantification of free fatty acids (FFA) in dairy products is important for quality control, nutritional, antimicrobial, authenticity, legislative, and flavor purposes. In this study, the performance of 2 widely used gas chromatographic flame ionization detection methods for determination of FFA in dairy products differing in lipid content and degree of lipolysis were evaluated. We used a direct on-column approach where the isolated FFA extract was injected directly and a derivatization approach where the FFA were esterified in the injector to methyl esters using tetramethylammonium hydroxide as a catalyst. A comprehensive validation was undertaken to establish method linearity, limits of detection, limits of quantification, accuracy, and precision. Linear calibrations of 3 to 700mg/L (R(2)>0.999) and 20 to 700mg/L (R(2)>0.997), and limits of detection and limits of quantification of 0.7 and 3mg/L and 5 and 20mg/L were obtained for the direct injection on-column and the derivatization method, respectively. Intraday precision of 1.5 to 7.2% was obtained for both methods. The direct injection on-column method had the lower levels of limits of detection and quantification, because FFA are directly injected onto the GC as opposed to the split injection used in the derivatization method. However, the direct injection on-column method experienced accumulative column phase deterioration and irreversible FFA absorption because of the acidic nature of the injection extract, which adversely affected method robustness and the quantification of some longer chain FFA. The derivatization method experienced issues with quantification of butyric acid at low concentrations because of coelution with the injection solvent peak, loss of polyunsaturated FFA due to degradation by tetramethylammonium hydroxide, and the periodic emergence of by-product peaks of the tetramethylammonium hydroxide reaction that interfered with the quantification of some short-chain FFA. The