46 CFR 153.557 - Special requirements for hydrochloric acid.

Science.gov (United States)

2010-10-01

... CARGOES SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Design and... system that carries hydrochloric acid must be lined with: (1) Natural rubber; (2) Neoprene; or (3) A material approved for hydrochloric acid tanks by the Commandant (CG-522). (b) Containment systems for...

Analysis of Sustainable Technologies for Acid Gas Removal

OpenAIRE

Dal Pozzo, Alessandro

2017-01-01

Acid gases, such as sulphur dioxide and hydrogen halides and – in a broad sense – carbon dioxide, are typical pollutants generated by combustion processes. Their removal by means of solid sorbents represent an efficient and cost-effective approach in dry acid gas treatment systems for waste incineration flue gas, while for CO2 capture the process is exploratively studied as a promising alternative to amine scrubbing. The present study addressed both aspects. In waste incineration flue gas ...

Using Willie's Acid-Base Box for Blood Gas Analysis

Science.gov (United States)

Dietz, John R.

2011-01-01

In this article, the author describes a method developed by Dr. William T. Lipscomb for teaching blood gas analysis of acid-base status and provides three examples using Willie's acid-base box. Willie's acid-base box is constructed using three of the parameters of standard arterial blood gas analysis: (1) pH; (2) bicarbonate; and (3) CO[subscript…

Volcanic air pollution hazards in Hawaii

Science.gov (United States)

Elias, Tamar; Sutton, A. Jeff

2017-04-20

Noxious sulfur dioxide gas and other air pollutants emitted from Kīlauea Volcano on the Island of Hawai‘i react with oxygen, atmospheric moisture, and sunlight to produce volcanic smog (vog) and acid rain. Vog can negatively affect human health and agriculture, and acid rain can contaminate household water supplies by leaching metals from building and plumbing materials in rooftop rainwater-catchment systems. U.S. Geological Survey scientists, along with health professionals and local government officials are working together to better understand volcanic air pollution and to enhance public awareness of this hazard.

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

Science.gov (United States)

2013-08-28

... DEPARTMENT OF TRANSPORTATION Pipeline and Hazardous Materials Safety Administration [Docket No. PHMSA-2013-0185] Pipeline Safety: Notice to Operators of Hazardous Liquid and Natural Gas Pipelines of a Recall on Leak Repair Clamps Due to Defective Seal AGENCY: Pipeline and Hazardous Materials Safety...

The Genealogical Tree of Ethanol: Gas-phase Formation of Glycolaldehyde, Acetic Acid, and Formic Acid

Science.gov (United States)

Skouteris, Dimitrios; Balucani, Nadia; Ceccarelli, Cecilia; Vazart, Fanny; Puzzarini, Cristina; Barone, Vincenzo; Codella, Claudio; Lefloch, Bertrand

2018-02-01

Despite the harsh conditions of the interstellar medium, chemistry thrives in it, especially in star-forming regions where several interstellar complex organic molecules (iCOMs) have been detected. Yet, how these species are synthesized is a mystery. The majority of current models claim that this happens on interstellar grain surfaces. Nevertheless, evidence is mounting that neutral gas-phase chemistry plays an important role. In this paper, we propose a new scheme for the gas-phase synthesis of glycolaldehyde, a species with a prebiotic potential and for which no gas-phase formation route was previously known. In the proposed scheme, the ancestor is ethanol and the glycolaldehyde sister species are acetic acid (another iCOM with unknown gas-phase formation routes) and formic acid. For the reactions of the new scheme with no available data, we have performed electronic structure and kinetics calculations deriving rate coefficients and branching ratios. Furthermore, after a careful review of the chemistry literature, we revised the available chemical networks, adding and correcting several reactions related to glycolaldehyde, acetic acid, and formic acid. The new chemical network has been used in an astrochemical model to predict the abundance of glycolaldehyde, acetic acid, and formic acid. The predicted abundance of glycolaldehyde depends on the ethanol abundance in the gas phase and is in excellent agreement with the measured one in hot corinos and shock sites. Our new model overpredicts the abundance of acetic acid and formic acid by about a factor of 10, which might imply a yet incomplete reaction network.

Locating hazardous gas leaks in the atmosphere via modified genetic, MCMC and particle swarm optimization algorithms

Science.gov (United States)

Wang, Ji; Zhang, Ru; Yan, Yuting; Dong, Xiaoqiang; Li, Jun Ming

2017-05-01

Hazardous gas leaks in the atmosphere can cause significant economic losses in addition to environmental hazards, such as fires and explosions. A three-stage hazardous gas leak source localization method was developed that uses movable and stationary gas concentration sensors. The method calculates a preliminary source inversion with a modified genetic algorithm (MGA) and has the potential to crossover with eliminated individuals from the population, following the selection of the best candidate. The method then determines a search zone using Markov Chain Monte Carlo (MCMC) sampling, utilizing a partial evaluation strategy. The leak source is then accurately localized using a modified guaranteed convergence particle swarm optimization algorithm with several bad-performing individuals, following selection of the most successful individual with dynamic updates. The first two stages are based on data collected by motionless sensors, and the last stage is based on data from movable robots with sensors. The measurement error adaptability and the effect of the leak source location were analyzed. The test results showed that this three-stage localization process can localize a leak source within 1.0 m of the source for different leak source locations, with measurement error standard deviation smaller than 2.0.

Mechanisms of acid, weakly acidic and gas reflux after anti-reflux surgery

NARCIS (Netherlands)

Bredenoord, A. J.; Draaisma, W. A.; Weusten, B. L. A. M.; Gooszen, H. G.; Smout, A. J. P. M.

2008-01-01

BACKGROUND: Whereas it is well documented that fundoplication reduces acid reflux, the effects of the procedure on non-acid and gas reflux and the mechanisms through which this is achieved have not been fully elucidated. METHODS: In 14 patients, reflux was measured with impedance-pH monitoring

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

International Nuclear Information System (INIS)

Martin, H.L.; Nutt, A.W.; Myers, B.L.; Hightower, J.O.

1994-01-01

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 (CS 2 ) 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 (SO 2 ) gas is also generated during the cutting. SO 2 is almost impossible to inhale and has apparently prevented a similar injury during the cutting. SO 2 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 CS 2 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

Correlation between arterial blood gas analysis and peripheral blood gas analysis in acid-base unbalance state

Directory of Open Access Journals (Sweden)

Hyun Lee Kim

2012-06-01

Full Text Available Acid-base unbalance is most common problem in severe ill patient, especially in condition of abnormal renal function state. Acid-base unbalances are respiratory acidosis, respiratory alkalosis, metabolic acidosis, and metabolic alkalosis. Metabolic acidosis is frequently appeared in clinical state. Arterial blood gas analysis is considered as a basic test to the intensive care unit patient and emergency state. Recently some researches were done, comparing with arterial blood gas analysis and venous blood gas analysis. Because of venous blood sampling is safer than arterial blood gas analysis, and beside not so different among them for detecting pH, pCO2, HCO3, except pO2 measuring. This research was done in emergency room, and for explaining no different between arterial blood gas analysis and peripheral blood gas analysis result in acid-base unbalance state patient. Especially in kidney functions decreased state. : The study was done from March, 2010 to January, 2011. The object was 89 peoples who came to emergency room for treating internal medicine problem. (Women 53, average age: 66.7±12.1 Then compare between arterial blood gas analysis and peripheral blood gas analysis. Result: The mean arterial minus venous difference for pH, pCO2, and bicarbonate was −0.0170, 2.6528, and 0.6124. Bland-Altman plot was done for predicting agreement of two groups, and the scale was pH −2.95 to 4.17, pCO2 −4.45 to 9.76, bicarbonate −2.95 to 4.16, in 95% relative. Conclusion: The peripheral blood gas pH, pCO2, bicarbonate level is almost same as arterial blood gas analysis results. And enough to measuring acid-base unbalance state, in absent of arterial blood testing.

An Experimental and Computational Study of the Gas-Phase Acidities of the Common Amino Acid Amides.

Science.gov (United States)

Plummer, Chelsea E; Stover, Michele L; Bokatzian, Samantha S; Davis, John T M; Dixon, David A; Cassady, Carolyn J

2015-07-30

Using proton-transfer reactions in a Fourier transform ion cyclotron resonance mass spectrometer and correlated molecular orbital theory at the G3(MP2) level, gas-phase acidities (GAs) and the associated structures for amides corresponding to the common amino acids have been determined for the first time. These values are important because amino acid amides are models for residues in peptides and proteins. For compounds whose most acidic site is the C-terminal amide nitrogen, two ions populations were observed experimentally with GAs that differ by 4-7 kcal/mol. The lower energy, more acidic structure accounts for the majority of the ions formed by electrospray ionization. G3(MP2) calculations predict that the lowest energy anionic conformer has a cis-like orientation of the [-C(═O)NH](-) group whereas the higher energy, less acidic conformer has a trans-like orientation of this group. These two distinct conformers were predicted for compounds with aliphatic, amide, basic, hydroxyl, and thioether side chains. For the most acidic amino acid amides (tyrosine, cysteine, tryptophan, histidine, aspartic acid, and glutamic acid amides) only one conformer was observed experimentally, and its experimental GA correlates with the theoretical GA related to side chain deprotonation.

Barrow hazards survey

International Nuclear Information System (INIS)

1980-06-01

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.)

40 CFR 63.1218 - What are the standards for hydrochloric acid production furnaces that burn hazardous waste?

Science.gov (United States)

2010-07-01

... acid production furnaces that burn hazardous waste? 63.1218 Section 63.1218 Protection of Environment... production furnaces that burn hazardous waste? (a) Emission limits for existing sources. You must not...% DRE. If you burn the dioxin-listed hazardous wastes F020, F021, F022, F023, F026, or F027 (see § 261...

Formation of itraconazole-succinic acid cocrystals by gas antisolvent cocrystallization.

Science.gov (United States)

Ober, Courtney A; Gupta, Ram B

2012-12-01

Cocrystals of itraconazole, an antifungal drug with poor bioavailability, and succinic acid, a water-soluble dicarboxylic acid, were formed by gas antisolvent (GAS) cocrystallization using pressurized CO(2) to improve itraconazole dissolution. In this study, itraconazole and succinic acid were simultaneously dissolved in a liquid solvent, tetrahydrofuran, at ambient conditions. The solution was then pressurized with CO(2), which decreased the solvating power of tetrahydrofuran and caused crystallization of itraconazole-succinic acid cocrystals. The cocrystals prepared by GAS cocrystallization were compared to those produced using a traditional liquid antisolvent, n-heptane, for crystallinity, chemical structure, thermal behavior, size and surface morphology, potential clinical relevance, and stability. Powder X-ray diffraction, Fourier transform infrared spectroscopy, differential scanning calorimetry, and scanning electron microscopy analyses showed that itraconazole-succinic acid cocrystals with physical and chemical properties similar to cocrystals produced using a traditional liquid antisolvent technique can be prepared by CO(2) antisolvent cocrystallization. The dissolution profile of itraconazole was significantly enhanced through GAS cocrystallization with succinic acid, achieving over 90% dissolution in less than 2 h. The cocrystals appeared stable against thermal stress for up to 4 weeks under accelerated stability conditions, showing only moderate decreases in their degree of crystallinity but no change in their crystalline structure. This study shows the utility of an itraconazole-succinic acid cocrystal for improving itraconazole bioavailability while also demonstrating the potential for CO(2) to replace traditional liquid antisolvents in cocrystal preparation, thus making cocrystal production more environmentally benign and scale-up more feasible.

Techno-economic Analysis of Acid Gas Removal and Liquefaction for Pressurized LNG

Science.gov (United States)

Lee, S. H.; Seo, Y. K.; Chang, D. J.

2018-05-01

This study estimated the life cycle cost (LCC) of an acid gas removal and a liquefaction processes for Pressurized LNG (PLNG) production and compared the results with the cost of normal LNG production. PLNG is pressurized LNG that is liquefied at a higher pressure and temperature than normal LNG. Due to the high temperature, the energy for liquefaction is reduced. The allowable CO2 concentration in PLNG is increased up to 3 mol% when the product pressure 25 bar. An amine process with 35 wt% of diethanolamine (DEA) aqueous solution and a nitrogen expansion cycle were selected for the acid gas removal and the liquefaction processes, respectively. Two types of CO2 concentration in the feed gas were investigated to analyze their impacts on the acid gas removal unit. When the CO2 concentration was 5 mol%, the acid gas removal unit was required for both LNG and PLNG production. However, the acid gas removal unit was not necessary in PLNG when the concentration was 0.5 mol% and the pressure was higher than 15 bar. The results showed that the LCC of PLNG was reduced by almost 35% relative to that of LNG when the PLNG pressure was higher than 15 bar.

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

Energy Technology Data Exchange (ETDEWEB)

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.

46 CFR 153.558 - Special requirements for phosphoric acid.

Science.gov (United States)

2010-10-01

... CARGOES SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Design and... containment system must be: (a) Lined with natural rubber or neoprene; (b) Lined with a material approved for phosphoric acid tanks by the Commandant (CG-522); or (c) Made of a stainless steel that resists corrosion by...

Improvement of gas chromatographic analysis for organic acids and ...

African Journals Online (AJOL)

Yomi

2010-08-27

Aug 27, 2010 ... short retention time and fair recognition peak of the compounds were obtained under the ... GC for acid and solvent analysis from ABE fermentation ... FID was kept at 230°C. Nitrogen gas was used as a carrier gas at a.

Experimental study of influence characteristics of flue gas fly ash on acid dew point

Science.gov (United States)

Song, Jinhui; Li, Jiahu; Wang, Shuai; Yuan, Hui; Ren, Zhongqiang

2017-12-01

The long-term operation experience of a large number of utility boilers shows that the measured value of acid dew point is generally lower than estimated value. This is because the influence of CaO and MgO on acid dew point in flue gas fly ash is not considered in the estimation formula of acid dew point. On the basis of previous studies, the experimental device for acid dew point measurement was designed and constructed, and the acid dew point under different smoke conditions was measured. The results show that the CaO and MgO in the flue gas fly ash have an obvious influence on the acid dew point, and the content of the fly ash is negatively correlated with the temperature of acid dew point At the same time, the concentration of H2SO4 in flue gas is different, and the acid dew point of flue gas is different, and positively correlated with the acid dew point.

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

DEFF Research Database (Denmark)

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...

Non-Volcanic release of CO2 in Italy: quantification, conceptual models and gas hazard

Science.gov (United States)

Chiodini, G.; Cardellini, C.; Caliro, S.; Avino, R.

2011-12-01

Central and South Italy are characterized by the presence of many reservoirs naturally recharged by CO2 of deep provenance. In the western sector, the reservoirs feed hundreds of gas emissions at the surface. Many studies in the last years were devoted to (i) elaborating a map of CO2 Earth degassing of the region; (ii) to asses the gas hazard; (iii) to develop methods suitable for the measurement of the gas fluxes from different types of emissions; (iv) to elaborate the conceptual model of Earth degassing and its relation with the seismic activity of the region and (v) to develop physical numerical models of CO2 air dispersion. The main results obtained are: 1) A general, regional map of CO2 Earth degassing in Central Italy has been elaborated. The total flux of CO2 in the area has been estimated in ~ 10 Mt/a which are released to the atmosphere trough numerous dangerous gas emissions or by degassing spring waters (~ 10 % of the CO2 globally estimated to be released by the Earth trough volcanic activity). 2) An on line, open access, georeferenced database of the main CO2 emissions (~ 250) was settled up (http://googas.ov.ingv.it). CO2 flux > 100 t/d characterise 14% of the degassing sites while CO2 fluxes from 100 t/d to 10 t/d have been estimated for about 35% of the gas emissions. 3) The sites of the gas emissions are not suitable for life: the gas causes many accidents to animals and people. In order to mitigate the gas hazard a specific model of CO2 air dispersion has been developed and applied to the main degassing sites. A relevant application regarded Mefite d'Ansanto, southern Apennines, which is the largest natural emission of low temperature CO2 rich gases, from non-volcanic environment, ever measured in the Earth (˜2000 t/d). Under low wind conditions, the gas flows along a narrow natural channel producing a persistent gas river which has killed over a period of time many people and animals. The application of the physical numerical model allowed us to

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

International Nuclear Information System (INIS)

El-Zahhar, A.A.; El-Naggar, H.A.; Ahmed, M.

2005-01-01

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 HNO 3 . 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

Coalbed methane: from hazard to resource

Science.gov (United States)

Flores, R.M.

1998-01-01

Coalbed gas, which mainly consists of methane, has remained a major hazard affecting safety and productivity in underground coal mines for more than 100 yr. Coalbed gas emissions have resulted in outbursts and explosions where ignited by open lights, smoking or improper use of black blasting powder, and machinery operations. Investigations of coal gas outbursts and explosions during the past century were aimed at predicting and preventing this mine hazard. During this time, gas emissions were diluted with ventilation by airways (eg, tunnels, vertical and horizontal drillholes, shsfts) and by drainage boreholes. The 1970s 'energy crisis' led to studies of the feasibility of producing the gas for commercial use. Subsequent research on the origin, accumulation, distribution, availability, and recoverability has been pursued vigorously during the past two decades. Since the 1970s research investigations on the causes and effects of coal mine outbursts and gas emissions have led to major advances towards the recovery and development of coalbed methane for commercial use. Thus, coalbed methane as a mining hazard was harnessed as a conventional gas resource.Coalbed gas, which mainly consists of methane, has remained a major hazard affecting safety and productivity in underground coal mines for more than 100 years. Coalbed gas emissions have resulted in outbursts and explosions where ignited by open lights, smoking or improper use of black blasting powder, and machinery operations. Investigations of coal gas outbursts and explosions during the past century were aimed at predicting and preventing this mine hazard. During this time, gas emissions were diluted with ventilation by airways (e.g., tunnels, vertical and horizontal drillholes, shafts) and by drainage boreholes. The 1970's `energy crisis' led to studies of the feasibility of producing the gas for commercial use. Subsequent research on the origin, accumulation, distribution, availability, and recoverability has been

Capillary gas chromatographic analysis of mycolic acid cleavage products, cellular fatty acids, and alcohols of Mycobacterium xenopi.

OpenAIRE

Luquin, M; Lopez, F; Ausina, V

1989-01-01

The fatty acids, alcohols, and mycolic acids of 26 strains of Mycobacterium xenopi were studied by capillary gas chromatography and thin-layer chromatography. All strains contained alpha-, keto-, and omega-carboxymycolates. The primary mycolic acid cleavage product was hexacosanoic acid. The fatty acid patterns and, especially, the presence of 2-docosanol are characteristic markers of M. xenopi.

Gas chromatography/mass spectrometry analysis of very long chain fatty acids, docosahexaenoic acid, phytanic acid and plasmalogen for the screening of peroxisomal disorders

NARCIS (Netherlands)

Takemoto, Yasuhiko; Suzuki, Yasuyuki; Horibe, Ryoko; Shimozawa, Nobuyuki; Wanders, Ronald J. A.; Kondo, Naomi

2003-01-01

Very long chain fatty acids (VLCFAs) and docosahexaenoic acid (DHA), phytanic acid, and plasmalogens are usually measured individually. A novel method for the screening of peroxisomal disorders, using gas chromatography/mass spectrometry (GC/MS), was developed. Saturated and unsaturated fatty acids,

Hazardous waste disposal in relationship to radon gas emanation in atmosphere

International Nuclear Information System (INIS)

Fang, H.Y.

1990-01-01

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

Amine-oxide hybrid materials for acid gas separations

KAUST Repository

Bollini, Praveen; Didas, Stephanie A.; Jones, Christopher W.

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

Informing hazardous zones for on-board maritime hydrogen liquid and gas systems

Energy Technology Data Exchange (ETDEWEB)

Blaylock, Myra L. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Pratt, Joseph William [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Bran Anleu, Gabriela A. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Proctor, Camron [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

2018-01-01

The significantly higher buoyancy of hydrogen compared to natural gas means that hazardous zones defined in the IGF code may be inaccurate if applied to hydrogen. This could place undue burden on ship design or could lead to situations that are unknowingly unsafe. We present dispersion analyses to examine three vessel case studies: (1) abnormal external vents of full blowdown of a liquid hydrogen tank due to a failed relief device in still air and with crosswind; (2) vents due to naturally-occurring boil-off of liquid within the tank; and (3) a leak from the pipes leading into the fuel cell room. The size of the hydrogen plumes resulting from a blowdown of the tank depend greatly on the wind conditions. It was also found that for normal operations releasing a small amount of "boil- off" gas to regulate the pressure in the tank does not create flammable concentrations.

Determining the explosion risk level and the explosion hazard area for a group of natural gas wells

Science.gov (United States)

Gligor, A.; Petrescu, V.; Deac, C.; Bibu, M.

2016-11-01

Starting from the fact that the natural gas engineering profession is generally associated with a high occupational risk, the current paper aims to help increase the safety of natural gas wells and reduce the risk of work-related accidents, as well as the occurrence of professional illnesses, by applying an assessment method that has proven its efficiency in other industrial areas in combination with a computer-aided design software. More specifically, the paper focuses on two main research directions: assessing the explosion risk for employees working at natural gas wells and indicating areas with a higher explosion hazard by using a modern software that allows their presentation in 3D. The appropriate zoning of industrial areas allows to group the various functional areas function of the probability of the occurrence of a dangerous element, such as an explosive atmosphere and subsequently it allows also to correctly select the electrical and mechanical equipment that will be used in that area, since electrical apparatuses that are otherwise found in normal work environments cannot generally be used in areas with explosion hazard, because of the risk that an electric spark, an electrostatic discharge etc. ignites the explosive atmosphere.

Hazardous Waste Treatment Facility and skid-mounted treatment systems at Los Alamos

International Nuclear Information System (INIS)

Lussiez, G.W.; Zygmunt, S.J.

1994-01-01

To centralize treatment, storage, and areas for hazardous wastes, Los Alamos National Laboratory has designed a 1115 m2 hazardous waste treatment facility. The facility will house a treatment room for each of four kinds of wastes: nonradioactive characteristic wastes, nonradioactive listed wastes, radioactive characteristic wastes, and radioactive listed wastes. The facility will be used for repacking labpacks; bulking small organic waste volumes; processing scintillation vials; treating reactives such as lithium hydride and pyrophoric uranium; treating contaminated solids such as barium sand; treating plating wastes and other solutions with heavy metals and oxidizing organics: Separate treatment rooms will allow workers to avoid mixing waste types and prevent cross-contamination. The ventilation air from the treatment areas may contain hazardous or radioactive dust. Gas may also leak from process equipment. The gas treatment process includes separating solids and gases and neutralization or adsorption of the hazardous gases. The ventilation air from each room will first be filtered before being scrubbed in a common gas caustic scrubber on an outside pad. There are two levels of exhaust in each treatment room, one for heavy gases and another for light gases. Several features help mitigate or eliminate hazards due to spills and releases: each treatment room is sealed and under slight negative pressure; each room has its own HEPA filtration; to avoid mixing of incompatible wastes and reagents, portable individual spill-containment trays are used for skids, to limit the danger of spills, the waste is directly transferred from outside storage to the treatment room; to mitigate the consequences of a gas release in the room, mobile hoods are connected to the exhaust-air treatment system; the floor, walls, ceilings, fixtures, ducts, and piping are made of acid-resistant material or are coated

Feasibility study on application of volume acid fracturing technology to tight gas carbonate reservoir development

Directory of Open Access Journals (Sweden)

Nianyin Li

2015-09-01

Full Text Available How to effectively develop tight-gas carbonate reservoir and achieve high recovery is always a problem for the oil and gas industry. To solve this problem, domestic petroleum engineers use the combination of the successful experiences of North American shale gas pools development by stimulated reservoir volume (SRV fracturing with the research achievements of Chinese tight gas development by acid fracturing to propose volume acid fracturing technology for fractured tight-gas carbonate reservoir, which has achieved a good stimulation effect in the pilot tests. To determine what reservoir conditions are suitable to carry out volume acid fracturing, this paper firstly introduces volume acid fracturing technology by giving the stimulation mechanism and technical ideas, and initially analyzes the feasibility by the comparison of reservoir characteristics of shale gas with tight-gas carbonate. Then, this paper analyzes the validity and limitation of the volume acid fracturing technology via the analyses of control conditions for volume acid fracturing in reservoir fracturing performance, natural fracture, horizontal principal stress difference, orientation of in-situ stress and natural fracture, and gives the solution for the limitation. The study results show that the volume acid fracturing process can be used to greatly improve the flow environment of tight-gas carbonate reservoir and increase production; the incremental or stimulation response is closely related with reservoir fracturing performance, the degree of development of natural fracture, the small intersection angle between hydraulic fracture and natural fracture, the large horizontal principal stress difference is easy to form a narrow fracture zone, and it is disadvantageous to create fracture network, but the degradable fiber diversion technology may largely weaken the disadvantage. The practices indicate that the application of volume acid fracturing process to the tight-gas carbonate

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

International Nuclear Information System (INIS)

Palmer, H.B.; Sibulkin, M.; Strehlow, R.A.; Yang, C.H.

1978-03-01

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 H 2 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

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

Science.gov (United States)

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. Copyright © 2015 Elsevier Ltd. All rights reserved.

Gas migration from oil and gas fields and associated hazards

International Nuclear Information System (INIS)

Gurevich, A.E.; Endres, B.L.; Robertson Jr, J.O.; Chilingar, G.V.

1993-01-01

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

Hazardous fluid leak detector

Science.gov (United States)

Gray, Harold E.; McLaurin, Felder M.; Ortiz, Monico; Huth, William A.

1996-01-01

A device or system for monitoring for the presence of leaks from a hazardous fluid is disclosed which uses two electrodes immersed in deionized water. A gas is passed through an enclosed space in which a hazardous fluid is contained. Any fumes, vapors, etc. escaping from the containment of the hazardous fluid in the enclosed space are entrained in the gas passing through the enclosed space and transported to a closed vessel containing deionized water and two electrodes partially immersed in the deionized water. The electrodes are connected in series with a power source and a signal, whereby when a sufficient number of ions enter the water from the gas being bubbled through it (indicative of a leak), the water will begin to conduct, thereby allowing current to flow through the water from one electrode to the other electrode to complete the circuit and activate the signal.

Hazards associated with stage one-mining

International Nuclear Information System (INIS)

Anon.

1975-01-01

Radiation hazards in uranium mining arise from the presence of radon-222, a gas which can escape from exposed rock surfaces into the air. Radon daughter products have been associated with an increased incidence of respiratory lung cancer. Other hazards include the tailings which arise from the extraction of uranium ores. The tailings still contain most of the original radium and emit gamma rays and radon gas. The hazards associated with uranium enrichment and fuel manufacture are also discussed. (R.L.)

[Investigation of emergency capacities for occupational hazard accidents in silicon solar cell producing enterprises].

Science.gov (United States)

Yang, D D; Xu, J N; Zhu, B L

2016-11-20

Objective: To investigate and analyze the influential factors of occupational hazard acci-dents, emergency facilities and emergency management in Silicon solar cell producing enterprises, then to pro-vide scientific strategies. Methods: The methods of occupationally healthy field investigating, inspecting of ven-tilation effectiveness, setup of emergency program and wearing chemical suit were used. Results: The mainly occupational hazard accidents factors in the process of Silicon solar cell producing included poisoning chemi-cals, high temperature, onizing radiation and some workplaces. The poisoning chemicals included nitric acid, hydrofluoric acid, sulfuric acid, hydrochloric acid, sodium hydroxide, potassium hydroxide, chlorine, phos-phorus oxychloride, phosphorus pentoxide, nitrogen dioxide, ammonia, silane, and so on; the workplaces in-cluded the area of producing battery slides and auxiliary producing area. Among the nine enterprises, gas detec-tors were installed in special gas supplying stations and sites, but the height, location and alarmvalues of gas detectors in six enterprises were not according with standard criteria; emergency shower and eyewash equip-ment were installed in workplaces with strong corrosive chemicals, but the issues of waste water were not solved; ventilation systems were set in the workplaces with ammonia and silane, but not qualified with part lo-cations and parameters in two enterprises; warehouses with materials of acid, alkali, chemical ammonia and phosphorus oxychloride were equipped with positive - pressure air respirator resuscitator and emergency cabi-nets, but with insufficient quantity in seven enterprises and expiration in part of products. The error rate of set-up emergency program and wearing chemical cloth were 30%~100% and 10%~30%, respectively. Among the nine enterprises, there were emergency rescue plans for dangerous chemical accidents, but without profession-al heatstroke and irradiation accident emergency plans

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

Directory of Open Access Journals (Sweden)

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.

Increase of weakly acidic gas esophagopharyngeal reflux (EPR) and swallowing-induced acidic/weakly acidic EPR in patients with chronic cough responding to proton pump inhibitors.

Science.gov (United States)

Kawamura, O; Shimoyama, Y; Hosaka, H; Kuribayashi, S; Maeda, M; Nagoshi, A; Zai, H; Kusano, M

2011-05-01

Gastro-esophageal reflux disease (GERD)-related chronic cough (CC) may have multifactorial causes. To clarify the characteristics of esophagopharyngeal reflux (EPR) events in CC patients whose cough was apparently influenced by gastro-esophageal reflux (GER), we studied patients with CC clearly responding to full-dose proton pump inhibitor (PPI) therapy (CC patients). Ten CC patients, 10 GERD patients, and 10 healthy controls underwent 24-h ambulatory pharyngo-esophageal impedance and pH monitoring. Weakly acidic reflux was defined as a decrease of pH by >1 unit with a nadir pH >4. In six CC patients, monitoring was repeated after 8 weeks of PPI therapy. The number of each EPR event and the symptom association probability (SAP) were calculated. Symptoms were evaluated by a validated GERD symptom questionnaire. Weakly acidic gas EPR and swallowing-induced acidic/weakly acidic EPR only occurred in CC patients, and the numbers of such events was significantly higher in the CC group than in the other two groups (P pump inhibitor therapy abolished swallowing-induced acidic/weakly acidic EPR, reduced weakly acidic gas EPR, and improved symptoms (all P gas EPR and swallowing-induced acidic/weakly acidic EPR. A direct effect of acidic mist or liquid refluxing into the pharynx may contribute to chronic cough, while cough may also arise indirectly from reflux via a vago-vagal reflex in some patients. © 2011 Blackwell Publishing Ltd.

Gas-Phase IR Spectroscopy of Deprotonated Amino Acids

NARCIS (Netherlands)

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),

Gas chromatography of alkylphosphonic and dialkylphosphinic acids

International Nuclear Information System (INIS)

Gasco, L.; Barrera, R.; Ramirez, A.; Martin Munoz, N.

1978-01-01

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)

An emerging methodology of slope hazard assessment for natural gas pipelines

Energy Technology Data Exchange (ETDEWEB)

Zhou, Z.J.; O' Neil, G.; Rizkalla, M. [TransCanada PipeLines Ltd., Calgary, AB (Canada)

2000-07-01

A new slope assessment methodology has been developed by TransCanada PipeLines Ltd. in an effort to switch from a reactive to a proactive hazard management approach and to optimize maintenance expenditure. The company operates 37,000 km of natural gas gathering and transmission pipelines, portions of which traverse slopes and stream crossings. The newly developed rainfall-ground movement model provides site-specific ground movement predictions for approximately 1100 slopes and establishes a risk-ranked list of slopes upon which maintenance decisions can be based. The input to the predictive model is derived from internal and public information regarding site conditions. This information serves as input to a pipe-soil interaction model to determine the probability of pipeline failure for each slope. The ground movement for this model is limited to creep-type which is typically less than 100 mm per year. Landslides are not addressed in this paper. A system-wide database has been constructed for slopes to prioritize the slope movement hazards. The slope information includes geotechnical data such as bedrock geology, surficial geology, slope details, precipitation and erosion potential. Information related to the pipeline includes the location, age, size, as well as design pressure and temperature. 13 refs., 2 figs.

Electron beam treatment technology for exhaust gas for preventing acid rain

International Nuclear Information System (INIS)

Aoki, Shinji

1990-01-01

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.)

Thermodynamic properties of acid gases in mixture with natural gas and water

NARCIS (Netherlands)

Tang, X.

2011-01-01

The reliable removal of acid gas components, such as carbon dioxide (CO2) and hydrogen sulfide (H2S) from natural gas is an important technical challenge. Crude oil and hydrocarbon gas streams may contain high levels of CO2 and/or H2S as contaminants. It is desirable to prevent any contaminant to

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

KAUST Repository

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.

Radon gas in oil and natural gas production facilities

International Nuclear Information System (INIS)

Chandler, W.P.

1994-01-01

Radon gas is a naturally occurring radionuclide that can be found in some oil and natural gas production facilities, either as a contaminant in a natural gas stream or derived from Radium dissolved in formation waters. The gas itself is not normally a health hazard, but it's decay products, which can be concentrated by plate-out or deposition as a scale in process equipment, can be a health hazard for maintenance personnel. To evaluate possible health hazards, it is necessary to monitor for naturally occurring radioactive materials (NORM) in the gas stream and in the formation water. If Radon and/or Radium is found, a monitoring programme should be initiated to comply with National or State requirements. In some instances, it has been found necessary to dispose of silt and scale materials as low level radioactive waste. 8 refs

Estimation of brassylic acid by gas chromatography-mass spectrometry

Energy Technology Data Exchange (ETDEWEB)

Mohammed J. Nasrullah, Erica N. Pfarr, Pooja Thapliyal, Nicholas S. Dusek, Kristofer L. Schiele, Christy Gallagher-Lein, and James A. Bahr

2010-10-29

The main focus of this work is to estimate Brassylic Acid (BA) using gas chromatography-mass spectrometry (GC-MS). BA is a product obtained from the oxidative cleavage of Erucic Acid (EA). BA has various applications for making nylons and high performance polymers. BA is a 13 carbon compound with two carboxylic acid functional groups at the terminal end. BA has a long hydrocarbon chain that makes the molecule less sensitive to some of the characterization techniques. Although BA can be characterized by NMR, both the starting material (EA) and products BA and nonanoic acid (NA) have peaks at similar {delta}, ppm values. Hence it becomes difficult for the quick estimation of BA during its synthesis.

Seismic modeling of acid-gas injection in a deep saline reservoir

Energy Technology Data Exchange (ETDEWEB)

Ursenbach, C.P.; Lawton, D.C. [Calgary Univ., AB (Canada). Dept. of Geoscience, Consortium for Research in Elastic Wave Exploration Seismology

2008-07-01

Carbon dioxide (CO{sub 2}) and hydrogen sulfide (H{sub 2}S) are common byproducts of the energy industry. As such, remediation studies are underway to determine the feasibility of sequestering these byproducts in subsurface reservoirs, including deep saline reservoirs. Acid gas injection at smaller gas wells holds promise. However, in order for such injection programs to work, the progress of the injection plume must be tracked. A modeling study of fluid substitution was carried out to gain insight into the ability of seismic monitoring to distinguish pre- and post-injection states of the reservoir medium. The purpose of this study was to carry out fluid substitution calculations for the modeling of an injection process. A methodology that may be applied or adapted to a variety of acid-gas injection scenarios was also developed. The general approach involved determining acoustic properties at reservoir temperature and pressure of relevant fluids; obtaining elastic properties of the reservoir rock for some reference saturated state, and the elastic properties of the mineral comprising it; and, determining the change in reservoir elastic properties due to fluid substitution via Gassmann's equation. Water, brine and non-aqueous acid gas were the 3 fluids of interest in this case. The feasibility of monitoring was judged by the sensitivity of travel times and reflection coefficients to fluid substitution. 4 refs., 2 figs.

Health hazards and disaster potential of ground gas emissions at Furnas volcano, São Miguel, Azores

Science.gov (United States)

Baxter, Peter J.; Baubron, Jean-Claude; Coutinho, Rui

1999-09-01

A health hazard assessment of exposure to soil gases (carbon dioxide and radon) was undertaken in the village of Furnas, located in the caldera of an active volcano. A soil survey to map the area of soil gas flow was undertaken, gas emissions were monitored at fumaroles and in eight houses, and a preliminary radon survey of 23 houses in the main anomaly area was performed. Potential volcanic sources of toxic contamination of air, food, and water were also investigated, and ambient air quality was evaluated. About one-third (41 ha) of the houses were located in areas of elevated carbon dioxide soil degassing. Unventilated, confined spaces in some houses contained levels of carbon dioxide which could cause asphyxiation. Mean indoor radon levels exceeded UK and US action levels in the winter months. A tenfold increase in radon levels in one house over 2 h indicated that large and potentially lethal surges of carbon dioxide could occur without warning. Toxic exposures from the gaseous emissions and from contamination of soil and water were minimal, but sulphur dioxide levels were mildly elevated close to fumaroles. In contrast, evidence of dental fluorosis was manifested in the population of the nearby fishing village of Ribeira Quente where drinking water in the past had contained elevated levels of fluoride. The disaster potential of volcanic carbon dioxide in the area could also be associated with the hydrothermal system storing dissolved carbon dioxide beneath the village. Felt, or unfelt, seismic activity, or magma unrest, especially with a reawakening of explosive volcanic activity (30% probability in the next 100 years) could result in an increase in gas flow or even a gas burst from the hydrothermal system. A survey of all houses in Furnas is advised as structural measures to prevent the ingress of soil gases, including radon, were needed in some of the study houses. Evaluations of the human hazards of volcanic gases should be undertaken in all settlements in

A Real-Time Construction Safety Monitoring System for Hazardous Gas Integrating Wireless Sensor Network and Building Information Modeling Technologies.

Science.gov (United States)

Cheung, Weng-Fong; Lin, Tzu-Hsuan; Lin, Yu-Cheng

2018-02-02

In recent years, many studies have focused on the application of advanced technology as a way to improve management of construction safety management. A Wireless Sensor Network (WSN), one of the key technologies in Internet of Things (IoT) development, enables objects and devices to sense and communicate environmental conditions; Building Information Modeling (BIM), a revolutionary technology in construction, integrates database and geometry into a digital model which provides a visualized way in all construction lifecycle management. This paper integrates BIM and WSN into a unique system which enables the construction site to visually monitor the safety status via a spatial, colored interface and remove any hazardous gas automatically. Many wireless sensor nodes were placed on an underground construction site and to collect hazardous gas level and environmental condition (temperature and humidity) data, and in any region where an abnormal status is detected, the BIM model will alert the region and an alarm and ventilator on site will start automatically for warning and removing the hazard. The proposed system can greatly enhance the efficiency in construction safety management and provide an important reference information in rescue tasks. Finally, a case study demonstrates the applicability of the proposed system and the practical benefits, limitations, conclusions, and suggestions are summarized for further applications.

CO2 Capture from Flue Gas using Amino Acid Salt Solutions

DEFF Research Database (Denmark)

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

2009-01-01

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...

Stimulation of deep gas wells using HCl/formic acid system : lab studies and field application

Energy Technology Data Exchange (ETDEWEB)

Nasr-El-Din, H.A.; Al-Mutairi, S.; Al-Malki, B. [Saudi Aramco (Saudi Arabia); Metcalf, S.; Walters, W. [BJ Services Co USA, Houston, TX (United States)

2002-06-01

Well stimulation in the deep carbonate Khuff reservoirs in eastern Saudi Arabia is needed to remove drilling mud filter cakes and to enhance reservoir permeability. A non associated gas is being produced from the reservoirs. This gas is associated with the hydrogen sulfide content that varies from 0 to 10-mol per cent. The average reservoir temperature is 275 degrees F and initial reservoir pressure is 7,000 psi. A special system is needed to stimulate the carbonate reservoir because of this high bottomhole temperature and the corrosive nature of hydrochloric acid (HCl) at high temperature. A rotating disk method was used to determine the reaction rate of an HCl/formic acid system with reservoir rocks. Results from coreflood tests showed that the acid system creates deep wormholes in tight reservoir cores. Corrosion tests showed that the well tubulars could tolerate the acid system. A gelled 15-wt per cent HCl/9-wt per cent formic acid system successfully fractured 3 vertical wells in deep sour gas reservoirs without any operational problems. The treatment resulted in significant increases in gas production and flowing wellhead pressures. In addition, overflush of the treatment successfully eliminated the return of live acid after the treatment. 37 refs., 10 tabs., 17 figs.

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

Science.gov (United States)

Jia, Qianqian; Ji, Huiming; Zhang, Ying; Chen, Yalu; Sun, Xiaohong; Jin, Zhengguo

2014-07-15

Hierarchical nanostructured ZnO dandelion-like spheres were synthesized via solvothermal reaction at 200°C for 4h. The products were pure hexagonal ZnO with large exposure of (002) 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 0.25ppm. The response (Ra/Rg) toward 100ppm acetone was 33 operated at 230°C and the response time was as short as 3s. 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 (002) 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. Copyright © 2014 Elsevier B.V. All rights reserved.

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

Directory of Open Access Journals (Sweden)

Meleah D Boyle

Full Text Available 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.

Experimental evidence of nitrous acid formation in the electron beam treatment of flue gas

International Nuclear Information System (INIS)

Maetzing, H.; Namba, H.; Tokunaga, O.

1994-01-01

In the Electron Beam Dry Scrubbing (EBDS) process, flue gas from fossil fuel burning power plants is irradiated with accelerated (300-800 keV) electrons. Thereby, nitrogen oxide (NO x ) and sulfur dioxide (SO 2 ) traces are transformed into nitric and sulfuric acids, respectively, which are converted into particulate ammonium nitrate and sulfate upon the addition of ammonia. The powdery product can be filtered from the main gas stream and can be sold as agricultural fertilizer. A lot of experimental investigations have been performed on the EBDS process and computer models have been developed to interpret the experimental results and to predict economic improvements. According to the model calculations, substantial amounts of intermediate nitrous acid (HNO 2 ) are formed in the electron beam treatment of flue gas. The first experimental investigation about the formation of nitrous acid in an irradiated mixture of NO in synthetic air has been undertaken. Under these conditions, aerosol formation is avoided. UV spectra of the irradiated gas were recorded in the wavelength range λ = 345-375 nm. Both NO 2 and HNO 2 have characteristic absorption bands in this wavelength range. Calibration spectra of NO 2 were subtracted from the sample spectra. The remaining absorption bands can clearly be assigned to nitrous acid. The concentration of nitrous acid was determined by differential optical absorption. It was found lower than the model prediction. The importance of nitrous acid formation in the EBDS process needs to be clarified. (author)

Gas chromatography of alkylphosphonic and dialkyl phosphinic acids

International Nuclear Information System (INIS)

Gasco Sanchez, L.; Barrera Pinero, R.; Ramirez Caceres, A.; Martin Munoz, M.

1978-01-01

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

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

DEFF Research Database (Denmark)

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

New solvents based on the salts of amino acids have emerged as an alternative to the alkanolamine solutions, for the chemical absorption of CO2 from flue gas. But only few studies on amino acids as CO2 capturing agents have been performed so far. One of the interesting features of amino acid salt...... 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...... of 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....

Determination of Free Fatty Acids and Triglycerides by Gas Chromatography Using Selective Esterification Reactions

Energy Technology Data Exchange (ETDEWEB)

Kail, Brian W; Link, Dirk D; Morreale, Bryan D

2012-11-01

A method for selectively determining both free fatty acids (FFA) and triacylglycerides (TAGs) in biological oils was investigated and optimized using gas chromatography after esterification of the target species to their corresponding fatty acid methyl esters (FAMEs). The method used acid catalyzed esterification in methanolic solutions under conditions of varying severity to achieve complete conversion of more reactive FFAs while preserving the concentration of TAGs. Complete conversion of both free acids and glycerides to corresponding FAMEs was found to require more rigorous reaction conditions involving heating to 120°C for up to 2 h. Method validation was provided using gas chromatography–flame ionization detection, gas chromatography–mass spectrometry, and liquid chromatography–mass spectrometry. The method improves on existing methods because it allows the total esterified lipid to be broken down by FAMEs contributed by FFA compared to FAMEs from both FFA and TAGs. Single and mixed-component solutions of pure fatty acids and triglycerides, as well as a sesame oil sample to simulate a complex biological oil, were used to optimize the methodologies. Key parameters that were investigated included: HCl-to-oil ratio, temperature and reaction time. Pure free fatty acids were found to esterify under reasonably mild conditions (10 min at 50°C with a 2.1:1 HCl to fatty acid ratio) with 97.6 ± 2.3% recovery as FAMEs, while triglycerides were largely unaffected under these reaction conditions. The optimized protocol demonstrated that it is possible to use esterification reactions to selectively determine the free acid content, total lipid content, and hence, glyceride content in biological oils. This protocol also allows gas chromatography analysis of FAMEs as a more ideal analyte than glyceride species in their native state.

Degradation of gas-liquid gliding arc discharge on Acid Orange II

International Nuclear Information System (INIS)

Yan, J.H.; Liu, Y.N.; Bo, Zh.; Li, X.D.; Cen, K.F.

2008-01-01

The effects of pH value, initial concentration of dye solution and temperature on the degradation efficiency of Acid Orange II (AO7) using gas-liquid gliding arc discharge were investigated. The influences of pH value and temperature on degradation efficiency were not apparent. Increasing initial solution concentration caused the decrease of degradation rate and the increase of absolute degradation quantity. Considering energy efficiency and absolute degradation quantity, the gas-liquid gliding arc discharge is fit for treating high concentration organic wastewater. A possible mineralization pathway was proposed through the analysis of intermediate products detected by gas chromatograph coupled with mass spectrophotometer (GC-MS) and ion chromatograph (IC). Hydroxyl radicals reacted with the azo linkage-bearing carbon of a hydroxy-substituted ring, leading to the cleavage of -C-N- and degradation of AO7. The solution biodegradability was significantly improved (BOD 5 /COD from 0.02 to 0.43). The toxicity of intermediate products was lower than that of the initial Acid Orange II

Determination of Fatty Acid in Asparagus by Gas Chromatography

Directory of Open Access Journals (Sweden)

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.

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

Energy Technology Data Exchange (ETDEWEB)

Sun, Qi; Jiang, Lin; Gong, Liang; Sun, Jin-Hua, E-mail: sunjh@ustc.edu.cn

2016-08-15

Highlights: • Heat flows after mixing TBP with nitric acid are of different orders of magnitude. • Thermodynamics and kinetics of tributyl phosphate-nitric acid mixtures are derived. • Tributyl phosphate directly reacts with nitric acid and form organic red oil. • Thermal runaway could occur at 79 °C with a high nitric acid concentration. - Abstract: 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, C80 micro 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.

Amine-oxide hybrid materials for acid gas separations

KAUST Repository

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.

Feedlot lamb meat fatty acids profile characterization employing gas chromatography

Directory of Open Access Journals (Sweden)

M.I. Cruz-Gonzalez

2014-06-01

Full Text Available Fat is an important constituent in diet, not only as an energy source, but for its essential fatty acids associated to fats in foods, considering that some polyunsaturated fatty acids like linoleic, linolenic and arachidonic cannot be synthesized by superior animals like humans. Scientific evidence show that the fatty acids ingest can affect the thrombotic tendency, cardiac rhythm, endothelial function systematic inflammation, insulin sensibility and oxidative stress. Samples from 21 ovine crossbreds from Pelibuey, Blackbelly, Dorper and Katahadin (40 kg average weight feed with corn based balanced diets were taken from loin area 18 h after refrigeration. Saturated and polyunsaturated fatty acids levels were analyzed by gas chromatography. Results in this work showed that the healthy fatty acids levels are higher as compared to saturated fatty acids levels, indicating that this meat can influence consumer’s buying choice decision regarded to their health.

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

Science.gov (United States)

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.

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

International Nuclear Information System (INIS)

Campbell, J.A.; Lerner, B.D.; Bean, R.M.; Grant, K.E.; Lucke, R.B.; Mong, G.M.; Clauss, S.A.

1994-08-01

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

Historical and future emission of hazardous air pollutants (HAPs) from gas-fired combustion in Beijing, China.

Science.gov (United States)

Xue, Yifeng; Nie, Lei; Zhou, Zhen; Tian, Hezhong; Yan, Jing; Wu, Xiaoqing; Cheng, Linglong

2017-07-01

The consumption of natural gas in Beijing has increased in the past decade due to energy structure adjustments and air pollution abatement. In this study, an integrated emission inventory of hazardous air pollutants (HAPs) emitted from gas-fired combustion in Beijing was developed for the period from 2000 to 2014 using a technology-based approach. Future emission trends were projected through 2030 based on current energy-related and emission control policies. We found that emissions of primary HAPs exhibited an increasing trend with the rapid increase in natural gas consumption. Our estimates indicated that the total emissions of NO X , particulate matter (PM) 10 , PM 2.5 , CO, VOCs, SO 2 , black carbon, Pb, Cd, Hg, As, Cr, Cu, Ni, Zn, polychlorinated dibenzo-p-dioxins and dibenzofurans, and benzo[a]pyrene from gas-fired combustion in Beijing were approximately 22,422 t, 1042 t, 781 t, 19,097 t, 653 t, 82 t, 19 t, 0.6 kg, 0.1 kg, 43 kg, 52 kg, 0.3 kg, 0.03 kg, 4.3 kg, 0.6 kg, 216 μg, and 242 g, respectively, in 2014. To mitigate the associated air pollution and health risks caused by gas-fired combustion, stricter emission standards must be established. Additionally, combustion optimization and flue gas purification system could be used for lowering NO X emissions from gas-fired combustion, and gas-fired facilities should be continuously monitored based on emission limits. Graphical abstract Spatial distribution and typical live photos of gas-fired boiler in Beijing.

Gas Phase Hydrogenation of Levulinic Acid to gamma-Valerolactone

NARCIS (Netherlands)

Bonrath, Werner; Castelijns, Anna Maria Cornelia Francisca; de Vries, Johannes Gerardus; Guit, Rudolf Philippus Maria; Schuetz, Jan; Sereinig, Natascha; Vaessen, Henricus Wilhelmus Leonardus Marie

The gas phase hydrogenation of levulinic acid to gamma-valerolactone over copper and ruthenium based catalysts in a continuous fixed-bed reactor system was investigated. Among the catalysts a copper oxide based one [50-75 % CuO, 20-25 % SiO2, 1-5 % graphite, 0.1-1 % CuCO3/Cu(OH)(2)] gave

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

Directory of Open Access Journals (Sweden)

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.

A Three-Step Resolution-Reconfigurable Hazardous Multi-Gas Sensor Interface for Wireless Air-Quality Monitoring Applications.

Science.gov (United States)

Choi, Subin; Park, Kyeonghwan; Lee, Seungwook; Lim, Yeongjin; Oh, Byungjoo; Chae, Hee Young; Park, Chan Sam; Shin, Heugjoo; Kim, Jae Joon

2018-03-02

This paper presents a resolution-reconfigurable wide-range resistive sensor readout interface for wireless multi-gas monitoring applications that displays results on a smartphone. Three types of sensing resolutions were selected to minimize processing power consumption, and a dual-mode front-end structure was proposed to support the detection of a variety of hazardous gases with wide range of characteristic resistance. The readout integrated circuit (ROIC) was fabricated in a 0.18 μm CMOS process to provide three reconfigurable data conversions that correspond to a low-power resistance-to-digital converter (RDC), a 12-bit successive approximation register (SAR) analog-to-digital converter (ADC), and a 16-bit delta-sigma modulator. For functional feasibility, a wireless sensor system prototype that included in-house microelectromechanical (MEMS) sensing devices and commercial device products was manufactured and experimentally verified to detect a variety of hazardous gases.

Refractories for exhaust gas scrubbers

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-07-01

Primary metal smelters are recovering a greater percentage of their stack emissions because of increased global environmental pressures. Copper and nickel producers processing sulfide ore are under particular scrutiny for sulfur dioxide emissions. The use of various acid plant designs and associated scrubbers to capture the gas is commonplace. Failure of acid plant or sulfur dioxide control devices can be very expensive, both in terms of repair costs and lost production. Close attention should be paid to ensure smooth, long term and proper operation of these vessels. With INCO flash furnace shops smelter gases are treated immediately upon leaving the furnace in a particulate scrubber where the gases are cooled and de-dusted in a water spray chamber. The amount of chlorine and fluorine in the waste gas can vary widely, ranging from non-existent to being a major source of concern for refractory wear. Developed specifically for use in hazardous waste incinerators burning fluorine-containing materials, spall-resistant, high-purity alimina bricks were installed in various gas cleaning units in copper smelting plants. Because of the materials's combination of abrasion resistance, thermal cycling resistance, and chemical durability under conditions of variable SO(3) and fluorine attack, the material has proven to be more than adequate for the challenges of gas cleaning equipment. 2 refs.

Gas-phase salt bridge interactions between glutamic acid and arginine

NARCIS (Netherlands)

Jaeqx, S.; Oomens, J.; Rijs, A.M.

2013-01-01

The gas-phase side chain-side chain (SC-SC) interaction and possible proton transfer between glutamic acid (Glu) and arginine (Arg) residues are studied under low-temperature conditions in an overall neutral peptide. Conformation-specific IR spectra, obtained with the free electron laser FELIX, in

Safety aspects of gas centrifuge enrichment plants

International Nuclear Information System (INIS)

Hansen, A.H.

1987-01-01

Uranium enrichment by gas centrifuge is a commercially proven, viable technology. Gas centrifuge enrichment plant operations pose hazards that are also found in other industries as well as unique hazards as a result of processing and handling uranium hexafluoride and the handling of enriched uranium. Hazards also found in other industries included those posed by the use of high-speed rotating equipment and equipment handling by use of heavy-duty cranes. Hazards from high-speed rotating equipment are associated with the operation of the gas centrifuges themselves and with the operation of the uranium hexafluoride compressors in the tail withdrawal system. These and related hazards are discussed. It is included that commercial gas centrifuge enrichment plants have been designed to operate safely

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

DEFF Research Database (Denmark)

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...

Hybrid ATDL-gamma distribution model for predicting area source acid gas concentrations

Energy Technology Data Exchange (ETDEWEB)

Jakeman, A J; Taylor, J A

1985-01-01

An air quality model is developed to predict the distribution of concentrations of acid gas in an urban airshed. The model is hybrid in character, combining reliable features of a deterministic ATDL-based model with statistical distributional approaches. The gamma distribution was identified from a range of distributional models as the best model. The paper shows that the assumptions of a previous hybrid model may be relaxed and presents a methodology for characterizing the uncertainty associated with model predictions. Results are demonstrated for the 98-percentile predictions of 24-h average data over annual periods at six monitoring sites. This percentile relates to the World Health Organization goal for acid gas concentrations.

Acid gas control process and apparatus for waste fired incinerators

International Nuclear Information System (INIS)

Kubin, P.Z.; Stepan, J.E.

1992-01-01

This patent describes a process for reducing noxious emission produced in a waste material incinerator. It comprises incinerating solid waste material in a furnace section of the waste material incinerator; providing an additive to an additive supply storage unit; conveying the additive to an additive injection means that communicates with the furnace section of the waste material incinerator; injecting the additive into a turbulent reaction zone of the furnace section such that acid gas content, acid dewpoint temperature and the level of corrosion in the incinerator are reduced

Monitoring of Level of Radiation Hazards to the Community in the Settlement Around the Incandescent Gas Mantle Factory

International Nuclear Information System (INIS)

Suryawati

2000-01-01

The analyze of radiation internal hazards level of thoron (Rn-220) and its daughter to the community settlement around the incandescent gas mantle factory. The radiation hazard level can be indicated in the form of working level (WL) and sffsctive dose lungs received by the community. The working level and effective dose lungs is got from the measurement of radioactivity level of thoron (Rn-220) and its daugther and by using the mathematical formula calculation. The measurement of thoron radioactive concentration and its daughter. The value of woking level obtained, performance level for community range from 0,001-0,013 WL, equivalent with dose range from 0,014- 0,467 mSv. From the research result, it can be identified that the radiation hazard, because exceed the mean value of threshold thorium radioactive nuclide and its daughter product of natural radiation in back ground per year for word mean i.e. 0,336 mSv, but the value of this research result is far below the allowed value limit for the community is 0,12 WL and 1 mSv/year

Method for the routine quantitative gas chromatographic analysis of major free fatty acids in butter and cream.

Science.gov (United States)

Woo, A H; Lindsay, R C

1980-07-01

A rapid quantiative method was developed for routine analysis of the major, even carbon-numbered free fatty acids in butter and cream. Free fatty acids were isolated directly from intact samples by a modified silicic acid-potassium hydroxide arrestant column and were separated by gas chromatography with a 1.8 m x 2 mm inner diameter glass column packed with 10% neopentyl glycol adipate on 80/100 Chromosorb W. Purified, formic acid-saturated carrier gas was required for minimal peak tailing and extended column life. The accuracy and reproducibility of the mmethod was established through quantitative recovery studies of free fatty acid mixtures, free fatty acids added to butter, and replicate analysis of butter and cream samples.

Thermal runaway reaction hazards and mechanisms of hydroxylamine with acid/base contaminants

International Nuclear Information System (INIS)

Wei Chunyang; Saraf, Sanjeev R.; Rogers, William J.; Sam Mannan, M.

2004-01-01

Hydroxylamine (HA) has been involved in two incidents since 1999 because of its thermal instability and incompatibility. In this study, thermal runaway reactions of hydroxylamine with various concentrations of KOH and HCl were studied using the reactive system screening tool (RSST) and automatic pressure tracking adiabatic calorimeter (APTAC). The thermokinetic data, such as onset temperature, heat of reaction, maximum self-heat rate, maximum pressure rate, and non-condensable gas pressure, were compared with those of hydroxylamine solution without added impurity. Our study shows that the thermal decomposition behavior of hydroxylamine is affected by the presence of acid/base, and mixing of hydroxylamine with acid/base may cause thermal decomposition at lower temperatures. Different decomposition pathways can be initiated by hydrogen ion and hydroxide ion. The decomposition mechanisms of hydroxylamine in alkaline and acidic solutions are proposed based on the products, information from the literature, and quantum mechanical calculations. The experimental results are discussed in terms of the proposed reaction mechanisms

Hydrocarbon fuels from gas phase decarboxylation of hydrolyzed free fatty acid

KAUST Repository

Wang, Weicheng; Roberts, William L.; Stikeleather, Larry F.

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

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

Energy Technology Data Exchange (ETDEWEB)

England, G.C.; McGrath, T.P. [GE-Energy and Environmental Research Corp., Irvine, CA (United States); Gilmer, L. [Equilon Enterprises, Bellaire, TX (United States); Seebold, J.G. [Chevron Research and Technology Co., Richmond, CA (United States); Lev-On, M. [ARCO, Los Angeles, CA (United States); Hunt, T. [American Petroleum Institute, Washington, DC (United States)

2001-07-01

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 NO{sub x} 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)

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

International Nuclear Information System (INIS)

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 NO x 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)

[Determination a variety of acidic gas in air of workplace by Ion Chromatography].

Science.gov (United States)

Li, Shiyong

2014-10-01

To establish a method for determination of a variety of acid gas in the workplace air by Ion Chromatography. (hydrofluoric acid, hydrogen chloride or hydrochloric acid, sulfur anhydride or sulfuric acid, phosphoric acid, oxalic acid). The sample in workplace air was collected by the porous glass plate absorption tube containing 5 ml leacheate. (Sulfuric acid fog, phosphoric acid aerosol microporous membrane after collection, eluted with 5 ml of eluent.) To separated by AS14+AG14 chromatography column, by carbonate (2.0+1.0) mmol/L (Na(2)CO(3)-NaHCO(3)) as eluent, flow rate of 1 ml/min, then analyzed by electrical conductivity detector. The retain time was used for qualitative and the peak area was used for quantitation. The each ion of a variety of acid gas in the air of workplace were excellent in carbonate eluent separation. The linear range of working curve of 0∼20 mg/L. The correlation coefficient r>0.999; lower detection limit of 3.6∼115 µg/L; quantitative limit of 0.012∼0.53 mg/L; acquisition of 15L air were measured, the minimum detection concentration is 0.004 0∼0.13 mg/m(3). The recovery rate is 99.7%∼101.1%. In the sample without mutual interference ions. Samples stored at room temperature for 7 days. The same analysis method, the detection of various acidic gases in the air of workplace, simple operation, good separation effect, high sensitivity, high detection efficiency, easy popularization and application.

Transportation of hazardous goods

CERN Multimedia

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

Nanostructure Engineered Chemical Sensors for Hazardous Gas and Vapor Detection

Science.gov (United States)

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.

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

International Nuclear Information System (INIS)

Yanagisawa, Kazumichi; Kozawa, Takahiro; Onda, Ayumu; Kanazawa, Masazumi; Shinohara, Junichi; Takanami, Tetsuro; Shiraishi, Masatsugu

2009-01-01

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 CHClF 2 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 CHClF 2 -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 CHClF 2 -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

Compressed Gas Safety for Experimental Fusion Facilities

Energy Technology Data Exchange (ETDEWEB)

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.

Estimation of Fatty Acids in Corn Oil by Gas Capillary Chromatography

International Nuclear Information System (INIS)

Kamal, Mohammad A; Klein Peter

2007-01-01

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)

Regeneration of an aqueous solution from an acid gas absorption process by matrix stripping

Science.gov (United States)

Rochelle, Gary T [Austin, TX; Oyenekan, Babatunde A [Katy, TX

2011-03-08

Carbon dioxide and other acid gases are removed from gaseous streams using aqueous absorption and stripping processes. By replacing the conventional stripper used to regenerate the aqueous solvent and capture the acid gas with a matrix stripping configuration, less energy is consumed. The matrix stripping configuration uses two or more reboiled strippers at different pressures. The rich feed from the absorption equipment is split among the strippers, and partially regenerated solvent from the highest pressure stripper flows to the middle of sequentially lower pressure strippers in a "matrix" pattern. By selecting certain parameters of the matrix stripping configuration such that the total energy required by the strippers to achieve a desired percentage of acid gas removal from the gaseous stream is minimized, further energy savings can be realized.

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

Directory of Open Access Journals (Sweden)

Venu Gopal Bairi

2015-10-01

Full Text Available 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 TANIPANI matrix. UV-Visible and infrared spectroscopy studies provided information about the electronic interactions among tannin, polyaniline, and TiO2. Scanning electron microscopy (SEM along with energy dispersive X-ray spectroscopy (EDS and atomic force microscopy (AFM surface analysis techniques were used to investigate the metal oxide dispersions inside polyaniline matrix. Gas sensors were prepared by spin coating solutions of TANIPANI-TiO2 and TANIPANI composites onto glass slides. Sensors were tested at three different concentrations (20 ppm, 40 ppm, and 60 ppm of ammonia gas at ambient temperature conditions by measuring the changes in surface resistivity of the films with respect to time. Ammonia gas sensing plots are presented showing the response values, response times and recovery times. The TANIPANI-TiO2 composite exhibited better response and shorter recovery times when compared to TANIPANI control and other polyaniline composites that have been reported in the literature. For the first time a proposed mechanism of gas sensing basing on the polaron band localization and its effects on the gas sensing behavior of polyaniline are reported.

Symposium on the transportation of hazardous goods

Energy Technology Data Exchange (ETDEWEB)

Mackay, D; Canniff, W; Coleman, R J; Ellison, T D; Estrin, D

1980-06-11

A symposium on the transportation of hazardous goods sponsored by the University of Toronto, the Canadian Society for Chemical Engineering, and Oyez Ltd. (Toronto May 1980), in view of a 11/10/79 explosion at Mississauga, Ont., following derailment of a Canadian Pacific Railways train carrying chlorine gas, covers comments by D. MacKay (Univ. Toronto), on the importance of quantifying the probability of an accident in transporting such hazardous materials as LPG's, chlorine, and corrosive acids, and of formulating contingency plans to reduce the probability or mitigate the effects; by W. Canniff of the Canadian Chemical Producers Association, on that group's Transportation Emergency Assistance Plan, which relies on the shipper of the chemical involved in an accident to provide advice and assistance; by R.J. Coleman (San Clemente, Calif., Fire Dep.), on coordination of efforts between firefighting and other emergency-handling groups to avoid confusion; by T.D. Ellison (Transp. Can.), on proposed Canadian legislation on the transport of dangerous goods, which would adopt, among others, a product classification system now used for international sea transport and a new system of labeling packages; and by D. Estrin, on the limitations of this proposed legislation.

State of the art review of pressure liquefied gas container failure modes and associated projectile hazards

Energy Technology Data Exchange (ETDEWEB)

Leslie, I.R.M.; Birk, A.M.

1989-08-01

A study was carried out to investigate the state of knowledge about the failure of pressure liquified gas transport and storage tanks. A comprehensive literature search and review was carried out to assess the level of knowledge relating to the causes and characteristics of vessel ruptures. Specific parameters of interest were: the effect of vessel initial conditions (fill level, initial temperature, etc.) on rupture severity; the ability to predict the occurrence of boiling liquid expanding vapor explosions (BLEVE); and the effects of explosions such as blast waves and missile generation. The review revealed that there are several areas where knowledge is weak. These areas include: the effects of blast on structures, the prediction of hazards from, and size of, fireballs, and the understanding of failure modes of pressure liquified gas containers. It was concluded that an experimental program should be initiated to investigate the effects of container size, shape and loading conditions on the consequences of vessel rupture. 68 refs., 16 figs., 10 tabs.

Characterization and Health Risk Assessment of Volatile Organic Compounds in Gas Service Station Workers

Directory of Open Access Journals (Sweden)

Duangduan Yimrungruang

2008-07-01

Full Text Available Gas service station workers who work near volatile organic compounds (VOCs sources, such as gasoline vapor emissions, and motor vehicle exhausts, may be exposed to highly elevated VOCs levels. This study investigates air samples from gas service stations in Thailand to evaluate the health risks following inhalation exposure. Personal air samplings were obtained at nine gas service stations in Chonburi, Thailand from October to December 2007. The concentrations of benzene, toluene, ethylbenzene, xylenes, and hexane in the air from the workplaces were significantly higher than in a control group of office workers (p<0.05. However, all VOCs in these air samples were lower than TWA limit of Thailand and the OSHA standard. Samples of urine, collected after 8-h work periods which were analyzed for VOCs metabolites, including t,t muconic acid, hippuric acid, mandelic acid and m-hippuric acid, demonstrate that the average levels of metabolites in gas service station workers and in controls were close, except for t,t muconic acid of gas service station workers which displayed higher levels than the in the controls. The lifetime cancer and noncancer risks for the workers exposed to VOCs were also assessed. Results show that all nine gas service stations in this study had a elevated lifetime cancer risk ranging from 53 to 630 per million, thus exceeding the normal risk of 1 per million. For noncancer risks, the levels in all gas stations ranged between 0.03 and 0.4, which is well below the reference hazard level of 1.0. Benzene may the most important cause of both cancer and noncancer risk followed by 1,3 butadiene.

New York hazardous substances emergency events surveillance: learning from hazardous substances releases to improve safety

International Nuclear Information System (INIS)

Welles, Wanda Lizak; Wilburn, Rebecca E.; Ehrlich, Jenny K.; Floridia, Christina M.

2004-01-01

Since 1993, the New York State Department of Health, funded by the Agency for Toxic Substances and Disease Registry, has collected data about non-petroleum hazardous substances releases through the Hazardous Substances Emergency Events Surveillance (NYHSEES) project. This study investigates risk factors for hazardous substances releases that may result in public health consequences such as injury or reported health effects. The 6428 qualifying events that occurred during the 10-year-period of 1993-2002 involved 8838 hazardous substances, 842 evacuations, more than 75,419 people evacuated, and more than 3120 people decontaminated. These events occurred both at fixed facilities (79%) and during transport (21%). The causative factors most frequently contributing to reported events were equipment failure (39%) and human error (33%). Five of the 10 chemicals most frequently associated with injuries were also among the 10 chemicals most frequently involved in reported events: sulfuric acid, hydrochloric acid, ammonia, sodium hypochlorite, and carbon monoxide. The chemical categories most frequently associated with events, and with events with adverse health effects were volatile organic compounds (VOCs) and solvents, and acids. Events with releases of hazardous substances were associated with injuries to 3089 people including employees (37%), responders (12%), the general public (29%) and students (22%). The most frequently reported adverse health effects were respiratory irritation, headache, and nausea or vomiting. Most of the injured were transported to the hospital, treated, and released (55%) or treated at the scene (29%). These data have been used for emergency response training, planning, and prevention activities to reduce morbidity and mortality from future events

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

DEFF Research Database (Denmark)

Poulsen, Nina Aagaard; Eskildsen, Carl Emil; Skov, T.

or 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...

Survey of potential health and safety hazards of commercial-scale ethanol production facilities

Energy Technology Data Exchange (ETDEWEB)

Watson, A.P.; Smith, J.G.; Elmore, J.L.

1982-04-01

Generic safety and health aspects of commercial-scale (60 to 600 million L/y) anhydrous ethanol production were identified. Several common feedstocks (grains, roots and fibers, and sugarcane) and fuels (coal, natural gas, wood, and bagasse) were evaluated throughout each step of generic plant operation, from initial milling and sizing through saccharification, fermentation, distillation, and stillage disposal. The fermentation, digestion, or combustion phases are not particularly hazardous, although the strong acids and bases used for hydrolysis and pH adjustment should be handled with the same precautions that every industrial solvent deserves. The most serious safety hazard is that of explosion from grain dust or ethanol fume ignition and boiler/steam line overpressurization. Inhalation of ethanol and carbon dioxide vapors may cause intoxication or asphyxiation in unventilated areas, which could be particularly hazardous near equipment controls and agitating vats. Contact with low-pressure process steam would produce scalding burns. Benzene, used in stripping water from ethanol in the final distillation column, is a suspected leukemogen. Substitution of this fluid by alternative liquids is addressed.

Measurements for the determination of acid dew point and SO[sub 3] concentration in the flue gas of utility boilers

Energy Technology Data Exchange (ETDEWEB)

Derichs, W.; Menden, W.; Ebel, P.K. (RWE Energie AG, Bergheim (Germany))

1991-10-01

Until now, the well-known measuring systems for determining acid dewpoint have been applied primarily to flue gases from oil-fired combustion. Using an acid dewpoint measuring system which has now been available on the market for some time, it is possible to measure the acid dewpoint reliably and continuously in flue gas from coal-fired combustion, with low SO[sub 3] concentrations. This measuring system has also been used for flue gas from which the dust and sulphur have been removed as well as for untreated flue gas of conventional combustion systems with gas, oil, hard coal and brown coal firing and also in fluidized bed combustion systems. 6 refs., 11 figs., 2 tabs.

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

DEFF Research Database (Denmark)

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......Various models have been devoted to the operation mechanism of porous diffusion electrodes. They are, however, suffering from the lack of accuracy concerning the acid-film thickness on which they are based. In the present paper the limiting current density has been measured for oxygen reduction...... current density can be accomplished either by gas-phase diffusion or liquid-phase diffusion, and it is the latter that can be used in the film-thickness estimation. It is also important to mention that at such a limiting condition, both the thin-film model and the filmed agglomerate model reach the same...

Prevalence of hazardous exposures in veterinary practice

Energy Technology Data Exchange (ETDEWEB)

Wiggins, P.; Schenker, M.B.; Green, R.; Samuels, S.

1989-01-01

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.

Prevalence of hazardous exposures in veterinary practice

International Nuclear Information System (INIS)

Wiggins, P.; Schenker, M.B.; Green, R.; Samuels, S.

1989-01-01

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

White Paper on Potential Hazards Associated with Contaminated Cheesecloth Exposed to Nitric Acid Solutions

Energy Technology Data Exchange (ETDEWEB)

Hypes, Philip A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2016-09-20

This white paper addresses the potential hazards associated with waste cheesecloth that has been exposed to nitric acid solutions. This issue was highlighted by the cleanup of a 100 ml leak of aqueous nitric acid solution containing Heat Source (HS) plutonium on 21 June 2016. Nitration of cellulosic material is a well-understood process due to industrial/military applications of the resulting material. Within the Department of Energy complex, nitric acids have been used extensively, as have cellulosic wipes. If cellulosic materials are nitrated, the cellulosic material can become ignitable and in extreme cases, reactive. We have chemistry knowledge and operating experience to support the conclusion that all current wastes are safe and compliant. There are technical questions worthy of further experimental evaluation. An extent of condition evaluation has been conducted back to 2004. During this time period there have been interruptions in the authorization to use cellulosic wipes in PF-4. Limited use has been authorized since 2007 (for purposes other than spill cleanup), so our extent of condition includes the entire current span of use. Our evaluation shows that there is no indication that process spills involving high molarity nitric acid were cleaned up with cheesecloth since 2007. The materials generated in the 21 June leak will be managed in a safe manner compliant with all applicable requirements.

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

International Nuclear Information System (INIS)

Jia, Qianqian; Ji, Huiming; Zhang, Ying; Chen, Yalu; Sun, Xiaohong; Jin, Zhengguo

2014-01-01

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 a /R 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 a /R 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

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

OpenAIRE

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 triterpen...

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

CERN Document Server

Rondo, L.; 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.

2016-01-01

Sulfuric acid is widely recognized as a very important substance driving atmospheric aerosolnucleation. Based on quantum chemical calculations it has been suggested that the quantitative detectionof gas phase sulfuric acid (H2SO4) by use of Chemical Ionization Mass Spectrometry (CIMS) could be biased inthe presence of gas phase amines such as dimethylamine (DMA). An experiment (CLOUD7 campaign) was setup at the CLOUD (Cosmics Leaving OUtdoor Droplets) chamber to investigate the quantitative detection ofH2SO4in the presence of dimethylamine by CIMS at atmospherically relevant concentrations. For the first time inthe 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, neutralsulfuric acid clusters were measured with the CI-APi-TOFs. The CLOUD7 measurements show that in the presenceof dimethylamine (<5 to 70 pptv) the sulfuric acid monomer measured by the CIMS...

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

International Nuclear Information System (INIS)

Hussien, E.M.; Osman, N.N.; Haggag, A.M.

2009-01-01

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

Fatty Acid and Carbon Isotopic Evidence for type I Methanotrophs in Microbial Mats from a Shallow Marine Gas Seep, Coal Oil Point, CA.

Science.gov (United States)

Ding, H.; Valentine, D.

2005-12-01

To study the microbial community in a Southern California seep field, sediment and bacterial mat samples were collected from natural gas-bearing and gas-free surfaces at two distinct seeps in the Coal Oil Point seep field, offshore Santa Barbara. Fatty acids in these samples were extracted, analyzed and identified. Using gas chromatography (GC), more than 30 different fatty acids were separated. Generally, fatty acid concentrations in natural gas-bearing samples were about 5-fold higher compared to gas-free samples. Using gas chromatography mass sepctrometry (GC-MS), all separated fatty acids were identified in each sample. The major constituents included saturated 14:0, 16:0, 18:0, branched i-15, a-15 and unsaturated 16:1 and 18:1 series fatty acids. GC-IRMS (isotope ratio mass spectrometry) analysis provided the 13C of all major fatty acids and some 16:1 series fatty acids were found to be more depleted than -40% in samples associated with gas seepage. After treatment with dimethyl disufide (DMDS), the 16:1 series fatty acids were resolved into five distinct components, including common composition 16:1(7), bacterial specific i-16:1(7) and typical biomarkers of type I methnotrophs 16:1(8), 16(6) and 16:1(5), suggesting an important role for methnotrophs in seep sediments and microbial mats. These results provide evidence for the activity of type I methanotrophic bacteria in microbial mats and surficial sediments at the Coal Oil Point seep field, and have implications for methane cycling in this and other seep

Evaluation of non radiation dangerous in multipurpose reactor GAS

International Nuclear Information System (INIS)

Suwarto, S.

1998-01-01

Evaluation of the potential non irradiation dangerous in RSG-GAS included of : the fire dangerous, the chemical hazard and gas dangerous have been performed to evaluate its potential on causing the accident and evaluate the performance of the equipment to protect the accident. Evaluate the performance of the equipment to protect to accident . Evaluate to the fire dangerous performed by identified the potential dangerous of fire at each rooms and evaluate the performance of each equipment included of dry powder fire extinguishing system, hydrant system, fire detectors and alarm system. Evaluation to the chemical hazard and gas dangerous performed by identified the number and it's the management of chemical hazard in the chemical storage and laboratory. The result of evaluation included of data of the fire dangerous potential class and the performance of its equipment in each room in RSG-GAS and the data of the number and the management system of the chemical hazard and gas in chemical storage and chemical laboratory. From this evaluation it is concluded that the equipment of fire system are available to protect against the accident and the chemical hazard and gas potential are relating small, and has been managed properly

Application of a hazard and operability study method to hazard evaluation of a chemical unit of the power station.

Science.gov (United States)

Habibi, E; Zare, M; Barkhordari, A; Mirmohammadi, Sj; Halvani, Ghh

2008-12-28

The aim of this study was to identify the hazards, evaluate their risk factors and determine the measure for promotion of the process and reduction of accidents in the chemical unit of the power station. In this case and qualitative study, HAZOP technique was used to recognize the hazards and problems of operations on the chemical section at power station. Totally, 126 deviations were documented with various causes and consequences. Ranking and evaluation of identified risks indicate that the majority of deviations were categorized as "acceptable" and less than half of that were "unacceptable". The highest calculated risk level (1B) related to both the interruption of acid entry to the discharge pumps and an increased density of the acid. About 27% of the deviations had the lowest risk level (4B). The identification of hazards by HAZOP indicates that it could, systemically, assess and criticize the process of consumption or production of acid and alkali in the chemical unit of power plant.

A Fine-Tuned MOF for Gas and Vapor Separation: A Multipurpose Adsorbent for Acid Gas Removal, Dehydration, and BTX Sieving

KAUST Repository

Haja Mohideen, Mohamed Infas; Pillai, Renjith S.; Adil, Karim; Bhatt, Prashant; Belmabkhout, Youssef; Shkurenko, Aleksander; Maurin, Guillaume; Eddaoudi, Mohamed

2017-01-01

Summary The development of highly stable separation agents is recognized as a decisive step toward the successful deployment of energy-efficient and cost-effective separation processes. Here, we report the synthesis and construction of a metal-organic framework (MOF), kag-MOF-1, that has adequate structural and chemical features and affords a stable adsorbent with unique and appropriate adsorption properties for gas processing akin to acid gas removal, dehydration, and benzene-toluene-xylene (BTX) sieving. A combination of X-ray diffraction experiments, adsorption studies, mixed-gas breakthrough adsorption column testing, calorimetric measurements, and molecular simulations corroborated the exceptional separation performance of kag-MOF-1 and its prospective use as a multifunctional adsorbent. The unique adsorption properties of kag-MOF-1, resulting from the contracted pore system with aligned periodic array of exposed functionalities, attest to the prominence of this new generation of ultra-microporous material as a prospective practical adsorbent toward cost-effective and more simplified gas and vapor processing flowcharts for natural gas upgrading and flue gas scrubbing.

A Fine-Tuned MOF for Gas and Vapor Separation: A Multipurpose Adsorbent for Acid Gas Removal, Dehydration, and BTX Sieving

KAUST Repository

Haja Mohideen, Mohamed Infas

2017-10-19

Summary The development of highly stable separation agents is recognized as a decisive step toward the successful deployment of energy-efficient and cost-effective separation processes. Here, we report the synthesis and construction of a metal-organic framework (MOF), kag-MOF-1, that has adequate structural and chemical features and affords a stable adsorbent with unique and appropriate adsorption properties for gas processing akin to acid gas removal, dehydration, and benzene-toluene-xylene (BTX) sieving. A combination of X-ray diffraction experiments, adsorption studies, mixed-gas breakthrough adsorption column testing, calorimetric measurements, and molecular simulations corroborated the exceptional separation performance of kag-MOF-1 and its prospective use as a multifunctional adsorbent. The unique adsorption properties of kag-MOF-1, resulting from the contracted pore system with aligned periodic array of exposed functionalities, attest to the prominence of this new generation of ultra-microporous material as a prospective practical adsorbent toward cost-effective and more simplified gas and vapor processing flowcharts for natural gas upgrading and flue gas scrubbing.

Technology survey for real-time monitoring of plutonium in a vitrifier off-gas system

International Nuclear Information System (INIS)

Berg, J.M.; Veirs, D.K.

1996-01-01

We surveyed several promising measurement technologies for the real-time monitoring of plutonium in a vitrifier off-gas system. The vitrifier is being developed by Westinghouse Savannah River Corp. and will be used to demonstrate vitrification of plutonium dissolved in nitric acid for fissile material disposition. The risk of developing a criticality hazard in the off-gas processing equipment can be managed by using available measurement technologies. We identified several potential technologies and methods for detecting plutonium that are sensitive enough to detect the accumulation of a mass sufficient to form a criticality hazard. We recommend gross alpha-monitoring technologies as the most promising option for Westinghouse Savannah River Corp. to consider because that option appears to require the least additional development. We also recommend further consideration for several other technologies because they offer specific advantages and because gross alpha-monitoring could prove unsuitable when tested for this specific application

Comments on Potential Geologic and Seismic Hazards Affecting Proposed Liquefied Natural Gas Site in Santa Monica Bay, California

Science.gov (United States)

Ross, Stephanie L.; Lee, Homa J.; Parsons, Tom E.; Beyer, Larry A.; Boore, David M.; Conrad, James E.; Edwards, Brian D.; Fisher, Michael A.; Frankel, Arthur D.; Geist, Eric L.; Hudnut, Kenneth W.; Hough, Susan E.; Kayen, Robert E.; Lorenson, T.D.; Luco, Nicolas; McCrory, Patricia A.; McGann, Mary; Nathenson, Manuel; Nolan, Michael; Petersen, Mark D.; Ponti, Daniel J.; Powell, Charles L.; Ryan, Holly F.; Tinsley, John C.; Wills, Chris J.; Wong, Florence L.; Xu, Jingping

2008-01-01

In a letter to the U.S. Geological Survey (USGS) dated March 25, 2008, Representative Jane Harman (California 36th district) requested advice on geologic hazards that should be considered in the review of a proposed liquefied natural gas (LNG) facility off the California coast in Santa Monica Bay. In 2004, the USGS responded to a similar request from Representative Lois Capps, regarding two proposed LNG facilities offshore Ventura County, Calif., with a report summarizing potential geologic and seismic hazards (Ross and others, 2004). The proposed LNG Deepwater Port (DWP) facility includes single point moorings (SPMs) and 35 miles of underwater pipelines. The DWP submersible buoys, manifolds, and risers would be situated on the floor of the southern Santa Monica Basin, in 3,000 feet of water, about 23 miles offshore of the Palos Verdes Peninsula. Twin 24-inch diameter pipelines would extend northeastward from the buoys across the basin floor, up the basin slope and across the continental shelf, skirting north around the Santa Monica submarine canyon. Figure 1 provides locations of the project and geologic features. Acronyms are defined in table 1. This facility is being proposed in a region of known geologic hazards that arise from both the potential for strong earthquakes and geologic processes related to sediment transport and accumulation in the offshore environment. The probability of a damaging earthquake (considered here as magnitude 6.5 or greater) in the next 30 years within about 30 miles (50 km) of the proposed pipeline ranges from 16% at the pipeline's offshore end to 48% where it nears land (Petersen, 2008). Earthquakes of this magnitude are capable of producing strong shaking, surface fault offsets, liquefaction phenomena, landslides, underwater turbidity currents and debris flow avalanches, and tsunamis. As part of the DWP license application for the Woodside Natural Gas proposal in Santa Monica Bay (known as the OceanWay Secure Energy Project), Fugro

A new chemical system solution for acid gas removal

Energy Technology Data Exchange (ETDEWEB)

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.)

UPS and DFT investigation of the electronic structure of gas-phase trimesic acid

Energy Technology Data Exchange (ETDEWEB)

Reisberg, L., E-mail: rebban@ut.ee [Institute of Physics, University of Tartu, W. Oswaldi 1, EE-50411 Tartu (Estonia); Pärna, R. [Institute of Physics, University of Tartu, W. Oswaldi 1, EE-50411 Tartu (Estonia); MAX IV Laboratory, Lund University, Fotongatan 2, 225 94 Lund (Sweden); Kikas, A.; Kuusik, I.; Kisand, V. [Institute of Physics, University of Tartu, W. Oswaldi 1, EE-50411 Tartu (Estonia); Hirsimäki, M.; Valden, M. [Surface Science Laboratory, Optoelectronics Research Centre, Tampere University of Technology, FIN-33101 Tampere (Finland); Nõmmiste, E. [Institute of Physics, University of Tartu, W. Oswaldi 1, EE-50411 Tartu (Estonia)

2016-11-15

Highlights: • In the current study outer valence band electronic structure of benzene-1,3,5-tricarboxylic acid was interpreted. • Experimental and calculated trimesic acid (TMA) spectrum were compared to ones of benzene and benzoic acid. • It is shown that similarities between MO energies and shapes for benzene and TMA exists. • Addition of carboxyl groups to the benzene ring clearly correlates with increasing binding energy of HOMO. - Abstract: Benzene-1,3,5-tricarboxylic acid (trimesic acid, TMA) molecules in gas-phase have been investigated by using valence band photoemission. The photoelectron spectrum in the binding energy region from 9 to 22 eV is interpreted by using density functional theory calculations. The electronic structure of TMA is compared with benzene and benzoic acid in order to demonstrate changes in molecular orbital energies induced by addition of carboxyl groups to benzene ring.

Relocation of blood gas laboratory to the emergency department helps decrease lactic acid values.

Science.gov (United States)

Brazg, Jared; Huang, Phyllis; Weiner, Corey; Singh, Guneet; Likourezos, Antonios; Salem, Linda; Dickman, Eitan; Marshall, John

2018-03-12

Emergency Physicians often rely on Lactic Acid (LA) values to make important clinical decisions. Accuracy of LA values improve when blood gas analysis is performed in the emergency department (ED) as opposed to a satellite laboratory (SL). To investigate an association between blood gas laboratory location and accuracy of ED lactic acid samples. The study team evaluated lactic acid values from venous and arterial blood gas samples drawn between June 1, 2015 and September 30, 2016. The study was exempt from institutional review board approval. Samples were separated into two groups: those which were drawn prior to and after relocation of the blood gas laboratory to the ED. The data, including patient demographic characteristics, acute illness severity indices, and blood gas results were compared within and between each group using t-test for continuous variables and chi-square test for categorical variables. The primary outcome was the mean lactate value measured in the SL group in 2015 compared to the ED group in 2016. Potassium and creatinine values were measured between the two groups as secondary outcomes. Of the 21,595 consecutive samples drawn, 10,363 samples were from the SL group and 11,232 from the ED group. The SL group included 5458 (52.7%) women; mean (SD) age was 61.8 (21.0). The ED group contained 5860 (52.2%) women; mean (SD) age was 61.7 (20.5). Mean Emergency Severity Index (ESI) were the same in each group at 2.31 and rates of Systemic Inflammatory Response Syndrome (SIRS) were also equivalent in each group at 22.2%. Significant differences were found between LA values in the SL group (mean 2.21mmol/L) and in the ED group (mean 1.99mmol/L) with a p value of values in the SL group (mean 3.98meq/L) compared to the ED Group (mean 3.96meq/L) with a p value of 0.022. No significant difference was found between the creatinine values. These results suggest that mean lactate values decreased when measured in an ED blood gas laboratory and may provide more

Relocation of blood gas laboratory to the emergency department helps decrease lactic acid values.

Science.gov (United States)

Brazg, Jared; Huang, Phyllis; Weiner, Corey; Singh, Guneet; Likourezos, Antonios; Salem, Linda; Dickman, Eitan; Marshall, John

2018-03-20

Emergency physicians often rely on Lactic Acid (LA) values to make important clinical decisions. Accuracy of LA values improve when blood gas analysis is performed in the emergency department (ED) as opposed to a satellite laboratory (SL). To investigate an association between blood gas laboratory location and accuracy of ED lactic acid samples. The study team evaluated lactic acid values from venous and arterial blood gas samples drawn between June 1, 2015 and September 30, 2016. The study was exempt from institutional review board approval. Samples were separated into two groups: those which were drawn prior to and after relocation of the blood gas laboratory to the ED. The data, including patient demographic characteristics, acute illness severity indices, and blood gas results were compared within and between each group using t-test for continuous variables and chi-square test for categorical variables. The primary outcome was the mean lactate value measured in the SL group in 2015 compared to the ED group in 2016. Potassium and creatinine values were measured between the two groups as secondary outcomes. Of the 21,595 consecutive samples drawn, 10,363 samples were from the SL group and 11,232 from the ED group. The SL group included 5458 (52.7%) women; mean (SD) age was 61.8 (21.0). The ED group contained 5860 (52.2%) women; mean (SD) age was 61.7 (20.5). Mean Emergency Severity Index (ESI) were the same in each group at 2.31 and rates of Systemic Inflammatory Response Syndrome (SIRS) were also equivalent in each group at 22.2%. Significant differences were found between LA values in the SL group (mean 2.21mmol/L) and in the ED group (mean 1.99mmol/L) with a p value of values in the SL group (mean 3.98meq/L) compared to the ED Group (mean 3.96meq/L) with a p value of 0.022. No significant difference was found between the creatinine values. These results suggest that mean lactate values decreased when measured in an ED blood gas laboratory and may provide more

FLAMMABLE GAS TECHNICAL BASIS DOCUMENT

Energy Technology Data Exchange (ETDEWEB)

KRIPPS, L.J.

2005-02-18

This document describes the qualitative evaluation of frequency and consequences for double shell tank (DST) and single shell tank (SST) representative flammable gas accidents and associated hazardous conditions without controls. The evaluation indicated that safety-significant SSCs and/or TSRS were required to prevent or mitigate flammable gas accidents. Discussion on the resulting control decisions is included. This technical basis document was developed to support of the Tank Farms Documented Safety Analysis (DSA) and describes the risk binning process for the flammable gas representative accidents and associated represented hazardous conditions. The purpose of the risk binning process is to determine the need for safety-significant structures, systems, and components (SSC) and technical safety requirement (TSR)-level controls for a given representative accident or represented hazardous condition based on an evaluation of the event frequency and consequence.

FLAMMABLE GAS TECHNICAL BASIS DOCUMENT

Energy Technology Data Exchange (ETDEWEB)

KRIPPS, L.J.

2005-03-03

This document describes the qualitative evaluation of frequency and consequences for DST and SST representative flammable gas accidents and associated hazardous conditions without controls. The evaluation indicated that safety-significant structures, systems and components (SSCs) and/or technical safety requirements (TSRs) were required to prevent or mitigate flammable gas accidents. Discussion on the resulting control decisions is included. This technical basis document was developed to support WP-13033, Tank Farms Documented Safety Analysis (DSA), and describes the risk binning process for the flammable gas representative accidents and associated represented hazardous conditions. The purpose of the risk binning process is to determine the need for safety-significant structures, systems, and components (SSC) and technical safety requirement (TSR)-level controls for a given representative accident or represented hazardous condition based on an evaluation of the event frequency and consequence.

Government review of the countdown companies' 1991 acid gas emissions audits

Energy Technology Data Exchange (ETDEWEB)

1993-08-01

An acid gas emissions verification program was implemented in Ontario in 1990 as part of a program for regulating emissions that are precursors to acid rain. The verification program applied to four companies, three in the metals industry and one electric utility. These emitters were required to limit annual SO[sub 2] and nitrogen oxides emissions to specified levels in stages according to a set schedule. The four companies were required to prepare and submit sulfur mass balance procedures manuals, determine the overall uncertainty of their respective annual emissions, and engage an independent auditor to develop an audit protocol manual and conduct audits of the reported emissions. For Ontario Hydro, the auditor was also required to evaluate the continuous flue gas monitoring systems at the utility's fossil-fuel power plants. The auditors confirmed that the metallurgical companies' reported emissions were within the required limits. For Ontario Hydro, the audit also confirmed that both SO[sub 2] and nitrogen oxide emissions were within the limits specified for 1991. The auditor also indicated that there were no major discrepancies with the procedures manuals that affected the calculated SO[sub 2] and nitrogen oxides emissions. 6 refs., 2 tabs.

Identify alkylation hazards

International Nuclear Information System (INIS)

Scott, B.

1992-01-01

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

Chemical incidents resulted in hazardous substances releases in the context of human health hazards

Directory of Open Access Journals (Sweden)

Anna Pałaszewska-Tkacz

2017-02-01

Full Text Available Objectives: The research purpose was to analyze data concerning chemical incidents in Poland collected in 1999–2009 in terms of health hazards. Material and Methods: The data was obtained, using multimodal information technology (IT system, from chemical incidents reports prepared by rescuers at the scene. The final analysis covered sudden events associated with uncontrolled release of hazardous chemical substances or mixtures, which may potentially lead to human exposure. Releases of unidentified substances where emergency services took action to protect human health or environment were also included. Results: The number of analyzed chemical incidents in 1999–2009 was 2930 with more than 200 different substances released. The substances were classified into 13 groups of substances and mixtures posing analogous risks. Most common releases were connected with non-flammable corrosive liquids, including: hydrochloric acid (199 cases, sulfuric(VI acid (131 cases, sodium and potassium hydroxides (69 cases, ammonia solution (52 cases and butyric acid (32 cases. The next group were gases hazardous only due to physico-chemical properties, including: extremely flammable propane-butane (249 cases and methane (79 cases. There was no statistically significant trend associated with the total number of incidents. Only with the number of incidents with flammable corrosive, toxic and/or harmful liquids, the regression analysis revealed a statistically significant downward trend. The number of victims reported was 1997, including 1092 children and 18 fatalities. Conclusions: The number of people injured, number of incidents and the high 9th place of Poland in terms of the number of Seveso establishments, and 4 times higher number of hazardous industrial establishments not covered by the Seveso Directive justify the need for systematic analysis of hazards and their proper identification. It is advisable enhance health risk assessment, both qualitative and

Characterization of free and bound fatty acids in human gallstones by capillary gas liquid chromatography

International Nuclear Information System (INIS)

Channa, N.A.; Khand, F.D.; Noorani, M.A.; Bhanger, M.I.

2002-01-01

Forty-four human gallstone samples either of pure cholesterol or cholesterol and bilirubin were randomly selected and analyzed by capillary gas liquid chromatography for the relative percentage composition of free and total fatty acids. The results showed that bound fatty acids were present in higher amounts than the free fatty acids. Amongst the bound fatty acids the percentage occurrence for palmitic acid was highest followed by stearic, oleic, linoleic and myristic acids. Fatty acids myristic, palmitic and linoleic were present in higher amounts in cholesterol gallstones, whereas stearic acid in cholesterol and bilirubin gallstones. When compared, no significant difference (p < 0.05) in the levels of free and bound fatty acids were seen in gallstones of males and females. The results suggest that bound fatty acids have a role to play in the structure of gallstones. (author)

OAS proteins and cGAS: unifying concepts in sensing and responding to cytosolic nucleic acids.

Science.gov (United States)

Hornung, Veit; Hartmann, Rune; Ablasser, Andrea; Hopfner, Karl-Peter

2014-08-01

Recent discoveries in the field of innate immunity have highlighted the existence of a family of nucleic acid-sensing proteins that have similar structural and functional properties. These include the well-known oligoadenylate synthase (OAS) family proteins and the recently identified OAS homologue cyclic GMP-AMP (cGAMP) synthase (cGAS). The OAS proteins and cGAS are template-independent nucleotidyltransferases that, once activated by double-stranded nucleic acids in the cytosol, produce unique classes of 2'-5'-linked second messenger molecules, which - through distinct mechanisms - have crucial antiviral functions. 2'-5'-linked oligoadenylates limit viral propagation through the activation of the enzyme RNase L, which degrades host and viral RNA, and 2'-5'-linked cGAMP activates downstream signalling pathways to induce de novo antiviral gene expression. In this Progress article, we describe the striking functional and structural similarities between OAS proteins and cGAS, and highlight their roles in antiviral immunity.

Studies for the requirements of automatic and remotely controlled shutoff valves on hazardous liquids and natural gas pipelines with respect to public and environmental safety

Energy Technology Data Exchange (ETDEWEB)

Oland, C. Barry [XCEL Engineering, Inc. (United States); Rose, Simon D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Engineering Science and Technology Div.; Grant, Herb L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Fabrication, Hoisting and Rigging Div.; Lower, Mark D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Fabrication, Hoisting and Rigging Div.; Spann, Mark A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Facility Management Div.; Kirkpatrick, John R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Computational Sciences and Engineering Div.; Sulfredge, C. David [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Computational Sciences and Engineering Div.

2012-12-01

This study assesses the effectiveness of block valve closure swiftness in mitigating the consequences of natural gas and hazardous liquid pipeline releases on public and environmental safety. It also evaluates the technical, operational, and economic feasibility and potential cost benefits of installing automatic shutoff valves (ASVs) and remote control valves (RCVs) in newly constructed and fully replaced transmission lines. Risk analyses of hypothetical pipeline release scenarios are used as the basis for assessing: (1) fire damage to buildings and property in Class 1, Class 2, Class 3, and Class 4 high consequence areas (HCAs) caused by natural gas pipeline releases and subsequent ignition of the released natural gas; (2) fire damage to buildings and property in HCAs designated as high population areas and other populated areas caused by hazardous liquid pipeline releases and subsequent ignition of the released propane; and (3) socioeconomic and environmental damage in HCAs caused by hazardous liquid pipeline releases of crude oil. These risk analyses use engineering principles and fire science practices to characterize thermal radiation effects on buildings and humans and to quantify the total damage cost of socioeconomic and environmental impacts. The risk analysis approach used for natural gas pipelines is consistent with risk assessment standards developed by industry and incorporated into Federal pipeline safety regulations. Feasibility evaluations for the hypothetical pipeline release scenarios considered in this study show that installation of ASVs and RCVs in newly constructed and fully replaced natural gas and hazardous liquid pipelines is technically, operationally, and economically feasible with a positive cost benefit. However, these results may not apply to all newly constructed and fully replaced pipelines because site-specific parameters that influence risk analyses and feasibility evaluations often vary significantly from one pipeline segment to

Adsorption and Detection of Hazardous Trace Gases by Metal-Organic Frameworks.

Science.gov (United States)

Woellner, Michelle; Hausdorf, Steffen; Klein, Nicole; Mueller, Philipp; Smith, Martin W; Kaskel, Stefan

2018-06-19

The quest for advanced designer adsorbents for air filtration and monitoring hazardous trace gases has recently been more and more driven by the need to ensure clean air in indoor, outdoor, and industrial environments. How to increase safety with regard to personal protection in the event of hazardous gas exposure is a critical question for an ever-growing population spending most of their lifetime indoors, but is also crucial for the chemical industry in order to protect future generations of employees from potential hazards. Metal-organic frameworks (MOFs) are already quite advanced and promising in terms of capacity and specific affinity to overcome limitations of current adsorbent materials for trace and toxic gas adsorption. Due to their advantageous features (e.g., high specific surface area, catalytic activity, tailorable pore sizes, structural diversity, and range of chemical and physical properties), MOFs offer a high potential as adsorbents for air filtration and monitoring of hazardous trace gases. Three advanced topics are considered here, in applying MOFs for selective adsorption: (i) toxic gas adsorption toward filtration for respiratory protection as well as indoor and cabin air, (ii) enrichment of hazardous gases using MOFs, and (iii) MOFs as sensors for toxic trace gases and explosives. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Noble metal-catalyzed homogeneous and heterogeneous processes in treating simulated nuclear waste media with formic acid

International Nuclear Information System (INIS)

King, R.B.; Bhattacharyya, N.K.; Smith, H.D.

1995-09-01

Simulants for the Hanford Waste Vitrification Plant feed containing the major non-radioactive components Al, Cd, Fe, Mn, Nd, Ni, Si, Zr, Na, CO 3 2 -, NO 3 -, and NO 2 - were used to study reactions of formic acid at 90 degrees C catalyzed by the noble metals Ru, Rh, and/or Pd found in significant quantities in uranium fission products. Such reactions were monitored using gas chromatography to analyze the CO 2 , H 2 , NO, and N 2 O in the gas phase and a microammonia electrode to analyze the NH 4 +/NH 3 in the liquid phase as a function of time. The following reactions have been studied in these systems since they are undesirable side reactions in nuclear waste processing: (1) Decomposition of formic acid to CO 2 + H 2 is undesirable because of the potential fire and explosion hazard of H 2 . Rhodium, which was introduced as soluble RhCl 3 -3H 2 O, was found to be the most active catalyst for H 2 generation from formic acid above ∼ 80 degrees C in the presence of nitrite ion. The H 2 production rate has an approximate pseudo first-order dependence on the Rh concentration, (2) Generation of NH 3 from the formic acid reduction of nitrate and/or nitrite is undesirable because of a possible explosion hazard from NH 4 NO 3 accumulation in a waste processing plant off-gas system. The Rh-catalyzed reduction of nitrogen-oxygen compounds to ammonia by formic acid was found to exhibit the following features: (a) Nitrate rather than nitrite is the principal source of NH 3 . (b) Ammonia production occurs at the expense of hydrogen production. (c) Supported rhodium metal catalysts are more active than rhodium in any other form, suggesting that ammonia production involves heterogeneous rather than homogeneous catalysis

Are carboxyl groups the most acidic sites in amino acids? Gas-phase acidities, photoelectron spectra, and computations on tyrosine, p-hydroxybenzoic acid, and their conjugate bases.

Science.gov (United States)

Tian, Zhixin; Wang, Xue-Bin; Wang, Lai-Sheng; Kass, Steven R

2009-01-28

Deprotonation of tyrosine in the gas phase was found to occur preferentially at the phenolic site, and the conjugate base consists of a 70:30 mixture of phenoxide and carboxylate anions at equilibrium. This result was established by developing a chemical probe for differentiating these two isomers, and the presence of both ions was confirmed by photoelectron spectroscopy. Equilibrium acidity measurements on tyrosine indicated that deltaG(acid)(o) = 332.5 +/- 1.5 kcal mol(-1) and deltaH(acid)(o) = 340.7 +/- 1.5 kcal mol(-1). Photoelectron spectra yielded adiabatic electron detachment energies of 2.70 +/- 0.05 and 3.55 +/- 0.10 eV for the phenoxide and carboxylate anions, respectively. The H/D exchange behavior of deprotonated tyrosine was examined using three different alcohols (CF3CH2OD, C6H5CH2OD, and CH3CH2OD), and incorporation of up to three deuterium atoms was observed. Two pathways are proposed to account for these results, and all of the experimental findings are supplemented with B3LYP/aug-cc-pVDZ and G3B3 calculations. In addition, it was found that electrospray ionization of tyrosine from a 3:1 (v/v) CH3OH/H2O solution using a commercial source produces a deprotonated [M-H]- anion with the gas-phase equilibrium composition rather than the structure of the ion that exists in aqueous media. Electrospray ionization from acetonitrile, however, leads largely to the liquid-phase (carboxylate) structure. A control molecule, p-hydroxybenzoic acid, was found to behave in a similar manner. Thus, the electrospray conditions that are employed for the analysis of a compound can alter the isomeric composition of the resulting anion.

Trends in risks associated with gas

International Nuclear Information System (INIS)

Pequignot, H.; Bertin, M.

1980-01-01

'Gas' is regarded at present as one of the forms of energy which presents the least health problems. All studies comparing the hazards of the various forms of energy have come to the same conclusion. For reasons of method this article views the situation from the viewpoint of the responsibilities and liabilities of the gas undertakings. When the gas supplied to customers was produced from coal, the risks inherent in mining the coal were not added to those of the production and distribution of the gas. Likewise, the problems raised by the production and transport of petroleum products which may be used by the gas industry, apart from natural gas of course, will not be considered here. At the outset, three particular points deserve to be stressed: Hazards exist at the stage of use and not at that of production; in this respect, gas differs from nuclear power and coal and the problems of prevention are therefore quite different; The hazards have declined sharply in the course of the past 25 years, and even at the distribution stage they have become fewer than in the case of most other forms of energy; The collection of epidemiological data was, and still is, better than in other power industries

Gas Cylinder Safety, Course 9518

Energy Technology Data Exchange (ETDEWEB)

Glass, George [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2016-10-27

This course, Gas Cylinder Safety (#9518), presents an overview of the hazards and controls associated with handling, storing, using, and transporting gas cylinders. Standard components and markings of gas cylinders are also presented, as well as the process for the procurement, delivery, and return of gas cylinders at Los Alamos National Laboratory (LANL).

An analysis of land use planning and equity issues surrounding hazardous liquid and natural gas transmission pipelines in North Carolina

Science.gov (United States)

Osland, Anna Christine

Hazardous liquid and natural gas transmission pipelines have received limited attention by planning scholars even though local development decisions can have broad consequences if a rupture occurs. In this dissertation, I evaluated the implications of land-use planning for reducing risk to transmission pipeline hazards in North Carolina via three investigations. First, using a survey of planning directors in jurisdictions with transmission pipeline hazards, I investigated the land use planning tools used to mitigate pipeline hazards and the factors associated with tool adoption. Planning scholars have documented the difficulty of inducing planning in hazardous areas, yet there remain gaps in knowledge about the factors associated with tool adoption. Despite the risks associated with pipeline ruptures, I found most localities use few mitigation tools, and the adoption of regulatory and informational tools appear to be influenced by divergent factors. Whereas risk perception, commitment, capacity, and community context were associated with total tool and information tool use, only risk perception and capacity factors were associated with regulatory tool use. Second, using interviews of emergency managers and planning directors, I examined the role of agency collaboration for building mitigation capacity. Scholars have highlighted the potential of technical collaboration, yet less research has investigated how inter-agency collaboration shapes mitigation capacity. I identify three categories of technical collaboration, discuss how collaborative spillovers can occur from one planning area to another, and challenge the notion that all technical collaborations result in equal mitigation outcomes. Third, I evaluated characteristics of the population near pipelines to address equity concerns. Surprisingly, I did not find broad support for differences in exposure of vulnerable populations. Nonetheless, my analyses uncovered statistically significant clusters of vulnerable

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

Directory of Open Access Journals (Sweden)

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.

Acid monomer analysis in waterborne polymer systems by targeted labeling of carboxylic acid functionality, followed by pyrolysis - gas chromatography.

Science.gov (United States)

Brooijmans, T; Okhuijsen, R; Oerlemans, I; Schoenmakers, P J; Peters, R

2018-05-14

Pyrolysis - gas chromatography - (PyGC) is a common method to analyse the composition of natural and synthetic resins. The analysis of acid functionality in, for example, waterborne polyacrylates and polyurethanes polymers has proven to be difficult due to solubility issues, inter- and intramolecular interaction effects, lack of detectability in chromatographic analysis, and lack of thermal stability. Conventional analytical techniques, such as PyGC, cannot be used for the direct detection and identification of acidic monomers, due to thermal rearrangements that take place during pyrolysis. To circumvent this, the carboxylic acid groups are protected prior to thermal treatment by reaction with 2-bromoacetophenone. Reaction conditions are investigated and optimised wrt. conversion measurements. The aproach is applied to waterborne polyacryalates and the results are discussed. This approach enables identification and (semi)quantitative analysis of different acid functionalities in waterborne polymers by PyGC. Copyright © 2018 Elsevier B.V. All rights reserved.

A method for the purification of natural gas from acidic components

Energy Technology Data Exchange (ETDEWEB)

Grinman, B.Kh.

1981-01-01

In the method of purifying natural gas from acidic components by means of injecting it into a layer of natural absorbers for the purpose of increasing the level of recovering CO/sub 2/, a water bearing terrigenic layer, containing silicates, carbonates, and sulfates of alkaline earth metals and layer water with a pH of 7.0 to 9.0 are used. Example. Specimens of rock from the Shatlyk deposit, saturated with layer water with a general mineralization of 19.8% grams per liter and natural gas from the Northern Dengiskul deposit with a CO/sub 2/ content of 3.2 volumetric percentage were used. The installation with the core specimens was placed in a thermostat, and was blown through with helium until complete air pressure was attained, and afterwards, 14.1 liters of natural gas were supplied. The initial pressure was 40.1 kilogauss per square centimeter, the test temperature was 50/sup 0/, and the duration of the experiment was 20 days. After finishing the test, the amount of CO/sub 2/ left in the gas was determined and the amount of the CO/sub 2/ absorbed by rock was also determined. The amount of CO/sub 2/, which entered the reaction with rock was 60% of the general amount of CO/sub 2/ in natural gas. The amount of CO/sub 2/ absorbed by the rock was 10%.

The Use of natural fatty acids in processing tritium gas

International Nuclear Information System (INIS)

El-Sharnouby, A.K.; Abdelgeleel, M.; Eskander, S.B.

1997-01-01

Natural unsaturated fatty acid (e.g cotton, corn, litmus, castor and palm oils) were used to fix tritium gas. The data obtained show that the affinity of the different used natural oils fixation of hydrogen (tritium) was in the following order: cotton oils> corn oil> litmus oil> castor oil> palm oil. The quantity of hydrogen (tritium) which can be fixed by one gram cotton oil is about 5.824 ml H 2 (5.56 x 10 1 1 Bq tritium) while one gram corn oil can fix only 5.04 ml H 2 (4.811 x 10 1 1 Bq tritium). Tritiated cotton oil and corn oil can be solidified using an epoxy resin (Araldite-B-W-1193), the polymer sample can contain up to 5% by weight from hydrogenated (tritiated) oils. The results obtained show that the compressive strength measurements of the final solid waste forms (fatty acid/epoxy) increased with increasing curing time and decreased with increasing fatty acid content. The leachability of tritium from the final solid waste forms increased with increasing fatty acid content in the polymer matrix. The cumulative leach fraction of tritium varied between 4.00 x 10 -3 cm and 6.60 x 10 -3 cm according to the experimental conditions. 15 figs., 1 tab

Feasibility study of NaOH regeneration in acid gas removal unit using membrane electrolysis

Science.gov (United States)

Taufany, Fadlilatul; Pratama, Alvian; Romzuddin, Muhammad

2017-05-01

The world's energy demand is increasing with the development of human civilization. Due to limited energy resource, after 2020 fossil fuels thus is predicted will be replaced by renewable resources. Taking an example, one of the potential renewable energy to be considered is biogas, as its high content of methane, which can be produced via the fermentation process of the organic compounds under controlled anaerobic environment by utilizing the methanogen bacteria. However, prior the further use, this biogas must be purified from its impurities contents, i.e. acid gas of CO2 and H2S, up to 4% and 16 ppmv, respectively, in the acid gas removal unit. This such of purification efforts, will significantly increase the higher heating value of biogas, approximately from 600 to 900 Btu/Scf. During the purification process in this acid gas removal unit, NaOH solution is used as a liquid absorbent to reduce those acid gases content, in which the by-product of alkali salt (brine) was produced as waste. Here we report the feasibility study of the NaOH regeneration process in acid gas removal unit via membrane electrolysis technology, in which both the technical and economic aspects are taken account. To be precise in procedure, the anode semi-cell was filled with the brine solution, while the cathode semi-cell was filled with demineralized water, and those electrodes were separated by the cation exchange membrane. Furthermore, the applied potential was varied ranging from 5, 10, 15 and to 20 V, while the concentration of KCl electrolyte solutions were varied ranging from 0.01, 0.05, 0.1, and to 0.03 M. This study was conducted under controlled temperatures of 30 and 50 °C. Here we found that the % sodium recovery was increased along with the applied potential, temperature, and the decrease in KCl electrolyte concentration. We found that the best results, by means of the highest % sodium recovery, i.e. 97.26 %, was achieved under the experimental condition of temperature at 30

Hazardous Gas Production by Alpha Particles

International Nuclear Information System (INIS)

LaVerne, Jay A.

2001-01-01

This project focused on the production of hazardous gases in the radiolysis of solid organic matrices, such as polymers and resins, that may be associated with transuranic waste material. Self-radiolysis of radioactive waste is a serious environmental problem because it can lead to a change in the composition of the materials in storage containers and possibly jeopardize their integrity. Experimental determination of gaseous yields is of immediate practical importance in the engineering and maintenance of containers for waste materials. Fundamental knowledge on the radiation chemical processes occurring in these systems allows one to predict outcomes in materials or mixtures not specifically examined, which is a great aid in the management of the variety of waste materials currently overseen by Environmental Management

Smart multi-channel two-dimensional micro-gas chromatography for rapid workplace hazardous volatile organic compounds measurement.

Science.gov (United States)

Liu, Jing; Seo, Jung Hwan; Li, Yubo; Chen, Di; Kurabayashi, Katsuo; Fan, Xudong

2013-03-07

We developed a novel smart multi-channel two-dimensional (2-D) micro-gas chromatography (μGC) architecture that shows promise to significantly improve 2-D μGC performance. In the smart μGC design, a non-destructive on-column gas detector and a flow routing system are installed between the first dimensional separation column and multiple second dimensional separation columns. The effluent from the first dimensional column is monitored in real-time and decision is then made to route the effluent to one of the second dimensional columns for further separation. As compared to the conventional 2-D μGC, the greatest benefit of the smart multi-channel 2-D μGC architecture is the enhanced separation capability of the second dimensional column and hence the overall 2-D GC performance. All the second dimensional columns are independent of each other, and their coating, length, flow rate and temperature can be customized for best separation results. In particular, there is no more constraint on the upper limit of the second dimensional column length and separation time in our architecture. Such flexibility is critical when long second dimensional separation is needed for optimal gas analysis. In addition, the smart μGC is advantageous in terms of elimination of the power intensive thermal modulator, higher peak amplitude enhancement, simplified 2-D chromatogram re-construction and potential scalability to higher dimensional separation. In this paper, we first constructed a complete smart 1 × 2 channel 2-D μGC system, along with an algorithm for automated control/operation of the system. We then characterized and optimized this μGC system, and finally employed it in two important applications that highlight its uniqueness and advantages, i.e., analysis of 31 workplace hazardous volatile organic compounds, and rapid detection and identification of target gas analytes from interference background.

Request for Correction 12003 Greenhouse Gas Emissions Reporting from the Petroleum and Natural Gas Industry

Science.gov (United States)

Request for Correction by the U.S. Chamber of Commerce for information in Greenhouse Gas Emissions Reporting from the Petroleum Gas Industry that regarding methane emissions, volatile organic compounds, and hazardous air pollutants.

Airborne geophysical radon hazard mapping

International Nuclear Information System (INIS)

Walker, P.

1993-01-01

Shales containing uranium pose a radon health hazard even when covered by several meters of overburden. Such an alum shale in southern Norway has been mapped with a joint helicopter borne electromagnetic (HEM) and radiometric survey. Results are compared with ground spectrometer, radon emanometer and radon gas measurements in dwellings, and a model to predict radon gas concentrations from the airborne data is developed. Since the shale is conductive, combining the HEM data with the radiometric channel allows the shale to be mapped with greater reliability than if the radiometric channel were used alone. Radiometrically more active areas which do not pose a radon gas hazard can thus be separated from the shales which do. The ground follow-up work consisted of spectrometer and radon emanometer measurements over a uranium anomaly coinciding with a conductor. The correlation between the airborne uranium channel, the ground uranium channel and emanometry is extremely good, indicating that airborne geophysics can, in this case, be used to predict areas having a high radon potential. Contingency tables comparing both radon exhalation and concentration in dwellings with the airborne uranium data show a strong relationship exists between exhalation and the airborne data and while a relationship between concentration and the airborne data is present, but weaker

Survey of knowledge of hazards of chemicals potentially associated with the advanced isotope separation processes

International Nuclear Information System (INIS)

Chester, R.O.; Kirkscey, K.A.; Randolph, M.L.

1979-09-01

Hazards of chemical potentially associated with the advanced isotope separation processes are estimated based on open literature references. The tentative quantity of each chemical associated with the processes and the toxicity of the chemical are used to estimate this hazard. The chemicals thus estimated to be the most potentially hazardous to health are fluorine, nitric acid, uranium metal, uranium hexafluoride, and uranium dust. The estimated next most hazardous chemicals are bromine, hydrobromic acid, hydrochloric acid, and hydrofluoric acid. For each of these chemicals and for a number of other process-associated chemicals the following information is presented: (1) any applicable standards, recommended standards and their basis; (2) a brief discussion to toxic effects including short exposure tolerance, atmospheric concentration immediately hazardous to life, evaluation of exposures, recommended control procedures, chemical properties, and a list of any toxicology reviews; and (3) recommendations for future research

Survey of knowledge of hazards of chemicals potentially associated with the advanced isotope separation processes

Energy Technology Data Exchange (ETDEWEB)

Chester, R.O.; Kirkscey, K.A.; Randolph, M.L.

1979-09-01

Hazards of chemical potentially associated with the advanced isotope separation processes are estimated based on open literature references. The tentative quantity of each chemical associated with the processes and the toxicity of the chemical are used to estimate this hazard. The chemicals thus estimated to be the most potentially hazardous to health are fluorine, nitric acid, uranium metal, uranium hexafluoride, and uranium dust. The estimated next most hazardous chemicals are bromine, hydrobromic acid, hydrochloric acid, and hydrofluoric acid. For each of these chemicals and for a number of other process-associated chemicals the following information is presented: (1) any applicable standards, recommended standards and their basis; (2) a brief discussion to toxic effects including short exposure tolerance, atmospheric concentration immediately hazardous to life, evaluation of exposures, recommended control procedures, chemical properties, and a list of any toxicology reviews; and (3) recommendations for future research.

Mitigation of the most hazardous tank at the Hanford Site

International Nuclear Information System (INIS)

Reynolds, D.A.

1994-09-01

Various tanks at the Hanford Site have been declared to be unresolved safety problems. This means that the tank has the potential to be beyond the limits covered by the current safety documentation. Tank 241-SY-101 poses the greatest hazard. The waste stored in this tank has periodically released hydrogen gas which exceeds the lower flammable limits. A mixer pump was installed in this tank to stir the waste. Stirring the waste would allow the hydrogen to be released slowly in a controlled manner and mitigate the hazard associated with this tank. The testing of this mixer pump is reported in this document. The mixer pump has been successful in controlling the hydrogen concentration in the tank dome to below the flammable limit which has mitigated the hazardous gas releases

Hazard analysis in uranium hexafluoride production facility

International Nuclear Information System (INIS)

Marin, Maristhela Passoni de Araujo

1999-01-01

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)

Gas flushing through hyper-acidic crater lakes: the next steps within a reframed monitoring time window

Science.gov (United States)

Rouwet, Dmitri

2016-04-01

Tracking variations in the chemical composition, water temperature and pH of brines from peak-activity crater lakes is the most obvious way to forecast phreatic activity. Volcano monitoring intrinsically implies a time window of observation that should be synchronised with the kinetics of magmatic processes, such as degassing and magma intrusion. To decipher "how much time ago" a variation in degassing regime actually occurred before eventually being detected in a crater lake is key, and depends on the lake water residence time. The above reasoning assumes that gas is preserved as anions in the lake water (SO4, Cl, F anions), in other words, that scrubbing of acid gases is complete and irreversible. Less is true. Recent work has confirmed, by direct MultiGas measurement from evaporative plumes, that even the strongest acid in liquid medium (i.e. SO2) degasses from hyper-acidic crater lakes. The less strong acid HCl has long been recognised as being more volatile than hydrophyle in extremely acidic solutions (pH near 0), through a long-term steady increase in SO4/Cl ratios in the vigorously evaporating crater lake of Poás volcano. We now know that acidic gases flush through hyper-acidic crater lake brines, but we don't know to which extend (completely or partially?), and with which speed. The chemical composition hence only reflects a transient phase of the gas flushing through the lake. In terms of volcanic surveillance this brings the advantage that the monitoring time window is definitely shorter than defined by the water chemistry, but yet, we do not know how much shorter. Empirical experiments by Capaccioni et al. (in press) have tried to tackle this kinetic problem for HCl degassing from a "lab-lake" on the short-term (2 days). With this state of the art in mind, two new monitoring strategies can be proposed to seek for precursory signals of phreatic eruptions from crater lakes: (1) Tracking variations in gas compositions, fluxes and ratios between species in

Evaluation of Aroma in Oriental Tobaccos as Based On Valeric Acid Gas Chromatography

Directory of Open Access Journals (Sweden)

Dagnon S

2014-12-01

Full Text Available Levels of valeric acids (isovaleric and 3-methylvaleric in leaves and smoke of different tobacco types were quantified by capillary gas chromatography (GC using flame ionization detector (FID. The aroma characteristics of the smoke were scored by sensory evaluation. It was found that leaves of Oriental and burley tobaccos contain higher amounts of both valeric acid derivatives than Virginia tobaccos containing isovaleric acid but no 3-methylvaleric acid. Strong correlation between the aroma and pleasantness scores of smoke and the content of valeric acids in the leaves of Oriental tobaccos was observed, while it was not the case for leaves of Virginia and burley tobaccos. In all tobacco types no correlation between smoking characteristics and the content of valeric acids in the smoke was established. Regression models involving leaf isovaleric acid were developed that can be used to evaluate aroma and pleasantness of smoke in Oriental tobaccos. The data obtained allow the following conclusions to be drawn: a 3-methylvaleric acid may be a chemical marker to distinguish Virginia tobaccos from Oriental and burley tobaccos; b isovaleric acid content in leaves of Oriental tobaccos may be used for objective aroma evaluation that can be exploited for breeding and market purposes.

A rapid and simple procedure for monitoring valproic acid by gas chromatography

Directory of Open Access Journals (Sweden)

Mohamed Said Mostafa

2018-02-01

Full Text Available Valproic acid (VPA, a widely used antiepileptic drug, has a narrow therapeutic range of 50-100 μg/mL and shows large individual variability. It is very important to monitor the trough VPA concentration using a reliable method. The aim of this study was to develop and validate a rapid gas chromatographic (GC technique for VPA quantification in human plasma and to compare it with the traditional immunoassay method. VPA extraction from human serum was efficient by dichloromethane and hydrochloric acid using octanoic acid as an internal standard. GC analysis was performed using a gas-chromatograph equipped with a flame ionization detector (GC/FID. VPA detection and quantification were accomplished isothermally at 135°C on a Gs-BP 100% dimethylpolysiloxane capillary column (10 m×0.53 mm ID, 2.65 μm film thickness, Supelco, Bellefonte, PA. Injection port and detector temperature were 280°C. Retention times of VPA and internal standard were 1.83 min and 2.33 min, respectively. The calibration curve was linear over the concentration range of 5-320 μg/mL, with a lower limit of detection of 1.25 μg/mL. The internal and inter-day precision was less than 5.3% and 6.1%, respectively, and the accuracy was below 2.8%. VPA recovery was 94.6%. A quick and accurate method for VPA determination in human plasma was developed and validated. It resulted sufficiently selective and sensitive.

Acidic sweep gas with carbonic anhydrase coated hollow fiber membranes synergistically accelerates CO2 removal from blood.

Science.gov (United States)

Arazawa, D T; Kimmel, J D; Finn, M C; Federspiel, W J

2015-10-01

The use of extracorporeal carbon dioxide removal (ECCO2R) is well established as a therapy for patients suffering from acute respiratory failure. Development of next generation low blood flow (carbonic anhydrase (CA) immobilized bioactive hollow fiber membrane (HFM) which significantly accelerates CO2 removal from blood in model gas exchange devices by converting bicarbonate to CO2 directly at the HFM surface. This present study tested the hypothesis that dilute sulfur dioxide (SO2) in oxygen sweep gas could further increase CO2 removal by creating an acidic microenvironment within the diffusional boundary layer adjacent to the HFM surface, facilitating dehydration of bicarbonate to CO2. CA was covalently immobilized onto poly (methyl pentene) (PMP) HFMs through glutaraldehyde activated chitosan spacers, potted in model gas exchange devices (0.0151 m(2)) and tested for CO2 removal rate with oxygen (O2) sweep gas and a 2.2% SO2 in oxygen sweep gas mixture. Using pure O2 sweep gas, CA-PMP increased CO2 removal by 31% (258 mL/min/m(2)) compared to PMP (197 mL/min/m(2)) (Premoval by 17% (230 mL/min/m(2)) compared to pure oxygen sweep gas control (Premoval increased by 109% (411 mL/min/m(2)) (Premoval, and when used in combination with bioactive CA-HFMs has a synergistic effect to more than double CO2 removal while maintaining physiologic pH. Through these technologies the next generation of intravascular and paracorporeal respiratory assist devices can remove more CO2 with smaller blood contacting surface areas. A clinical need exists for more efficient respiratory assist devices which utilize low blood flow rates (removal efficiency by shifting equilibrium from bicarbonate to gaseous CO2, through either a bioactive carbonic anhydrase enzyme coating or bulk blood acidification with lactic acid. In this study we demonstrate a novel approach to local blood acidification using an acidified sweep gas in combination with a bioactive coating to more than double CO2 removal

Treatment of hazardous metals by in situ vitrification

International Nuclear Information System (INIS)

Koegler, S.S.; Buelt, J.L.

1989-02-01

Soils contaminated with hazardous metals are a significant problem to many Defense Program sites. Contaminated soils have ranked high in assessments of research and development needs conducted by the Hazardous Waste Remedial Action Program (HAZWRAP) in FY 1988 and FY 1989. In situ vitrification (ISV) is an innovative technology suitable for stabilizing soils contaminated with radionuclides and hazardous materials. Since ISV treats the material in place, it avoids costly and hazardous preprocessing exhumation of waste. In situ vitrification was originally developed for immobilizing radioactive (primarily transuranic) soil constituents. Tests indicate that it is highly useful also for treating other soil contaminants, including hazardous metals. The ISV process produces an environmentally acceptable, highly durable glasslike product. In addition, ISV includes an efficient off-gas treatment system that eliminates noxious gaseous emissions and generates minimal hazardous byproducts. This document reviews the Technical Basis of this technology. 5 refs., 7 figs., 2 tabs

Geological hazard monitoring system in Georgia

Science.gov (United States)

Gaprindashvili, George

2017-04-01

Georgia belongs to one of world's most complex mountainous regions according to the scale and frequency of Geological processes and damage caused to population, farmlands, and Infrastructure facilities. Geological hazards (landslide, debrisflow/mudflow, rockfall, erosion and etc.) are affecting many populated areas, agricultural fields, roads, oil and gas pipes, high-voltage electric power transmission towers, hydraulic structures, and tourist complexes. Landslides occur almost in all geomorphological zones, resulting in wide differentiation in the failure types and mechanisms and in the size-frequency distribution. In Georgia, geological hazards triggered by: 1. Activation of highly intense earthquakes; 2. Meteorological events provoking the disaster processes on the background of global climatic change; 3. Large-scale Human impact on the environment. The prediction and monitoring of Geological Hazards is a very wide theme, which involves different researchers from different spheres. Geological hazard monitoring is essential to prevent and mitigate these hazards. In past years in Georgia several monitoring system, such as Ground-based geodetic techniques, Debrisflow Early Warning System (EWS) were installed on high sensitive landslide and debrisflow areas. This work presents description of Geological hazard monitoring system in Georgia.

Sensitivity Analysis of Population in The Generation of Hazardous and Non-Harzardous Wastes, and Gas from Dumpsites of Ogbomosoland in Nigeria

Directory of Open Access Journals (Sweden)

Samson O. Ojoawo

2013-01-01

Full Text Available This paper applies the principles of system dynamics modeling in studying the pattern of population changes and the corresponding non-hazardous wastes and gas being generated from the dumpsites of Ogbomosoland, Nigeria. The five (5 Local government Areas (LGAs of Ogbomosoland were categorized as Urban (Ogbomoso North and Ogbomoso South and Rural (Oriire, Ogo Oluwa and Suurulere based on the size, population of residents, consumption pattern and socio-economic activities of the area. A sensitivity analysis of the simulated variables i.e the population, wastes and gas, was performed by employing the developed model results. Findings showed that the wastes and gas increased with the increased population in the 1000 years period. Also, gas production exceeds wastes generation rates for the rural LGAs in all cases. After a 25 years benchmark, when the simulated population of the urban and rural LGAs are respectively 303,411 and 344,735, the rates of waste generation are 3.33x106 and 6.22 x106 m 3 , while the corresponding rates of gas production is 2.44x103 and 6.47x103 m 3 in same order. The study concludes that wastes and gas generation from dumpsites are highly sensitive to population growth. It also concluded that the rate of gas generation is higher in organic wastes of the rural LGAs. The maximum population permissible in the model is 300,000 thus design of full-fledge landfills is recommended to replace the existing dumpsites in the study area.

Proceedings of emerging technologies for hazardous waste management

International Nuclear Information System (INIS)

Tedder, D.W.

1992-01-01

This book contains proceedings of emerging technologies for hazardous waste management. Topics covered include: Low-temperature oxidation of organic chemical wastes; Advanced waste minimization strategies; Treatment of manufactured gas plant (MGP) and similar wastes; Bioremediation of soils and sediments; Advances in radioactive waste treatment; Computer aides approaches to hazardous waste management; Advances in soil remediation; Low-temperature oxidation of organic chemical waste; Boremediation: Micro, meso, and macro-scale processes; In situ remediation techniques; Treatment of hazardous organics with radiation or solar energy; Technologies for management of municipal waste combustion residues; Environmental restoration and waste management; and Advanced separation and stabilization technologies

Simultaneous determination of oxalic, citric, nitrilotriacetic and ethylenediamenetetraacetic acids by gas liquid chromatography of their methyl esters

International Nuclear Information System (INIS)

Eskell, C.J.; Pick, M.E.

1980-04-01

A procedure for simultaneous determination of ethylenediaminetetraacetic acid (EDTA), nitrilotriacetic acid (NTA), citric acid and oxalic acid by gas liquid chromatography is described. The involatile acids are first concerted to their volatile methyl ester derivatives by reaction with boron trifluoride in methanol. Transition metal ions (Fe 3+ , Cr 3+ and Ni 2+ ) which will be present in decontamination liquors from nuclear reactors, and form strong chelates with the acids, have been shown to cause no interference to the esterification reaction. The esters were separated by temperature programming on a 3.5 metre capillary column packed with 3% OV1 on Diatomite CQ and were detected by flame ionisation. (author)

Miniaturized Planar Room Temperature Ionic Liquid Electrochemical Gas Sensor for Rapid Multiple Gas Pollutants Monitoring.

Science.gov (United States)

Wan, Hao; Yin, Heyu; Lin, Lu; Zeng, Xiangqun; Mason, Andrew J

2018-02-01

The growing impact of airborne pollutants and explosive gases on human health and occupational safety has escalated the demand of sensors to monitor hazardous gases. This paper presents a new miniaturized planar electrochemical gas sensor for rapid measurement of multiple gaseous hazards. The gas sensor features a porous polytetrafluoroethylene substrate that enables fast gas diffusion and room temperature ionic liquid as the electrolyte. Metal sputtering was utilized for platinum electrodes fabrication to enhance adhesion between the electrodes and the substrate. Together with carefully selected electrochemical methods, the miniaturized gas sensor is capable of measuring multiple gases including oxygen, methane, ozone and sulfur dioxide that are important to human health and safety. Compared to its manually-assembled Clark-cell predecessor, this sensor provides better sensitivity, linearity and repeatability, as validated for oxygen monitoring. With solid performance, fast response and miniaturized size, this sensor is promising for deployment in wearable devices for real-time point-of-exposure gas pollutant monitoring.

75 FR 63774 - Pipeline Safety: Safety of On-Shore Hazardous Liquid Pipelines

Science.gov (United States)

2010-10-18

... DEPARTMENT OF TRANSPORTATION Pipeline and Hazardous Materials Safety Administration 49 CFR Part... Pipelines AGENCY: Pipeline and Hazardous Materials Safety Administration (PHMSA), Department of... Gas Pipeline Safety Act of 1968, Public Law 90-481, delegated to DOT the authority to develop...

Selected problems of mine ventilation under conditions of gas and fire hazards. [Poland

Energy Technology Data Exchange (ETDEWEB)

Rosiek, F; Sikora, M; Urbanski, J

1984-01-01

Activities of the the Department for Ventilation, Fires and Occupational Safety in Wroclaw are evaluated. Until 1981 the Department concentrated its research programs on ventilation in copper mines; since 1982 its programs have also covered ventilation and hazards of endogenous fire in black coal mines. The Department investigated hazards of coal spontaneous combustion in Lower Silesian coal mines and proved that the hazards are associated with occurrence of specific layers in coal seams. When coal left in the goaf area came from a layer prone to spontaneous combustion hazards of endogenous fires were high. The Department developed a method for fire prevention using periodic reversal of goaf ventilation. Schemes for reverse ventilation are discussed.

St. Louis area earthquake hazards mapping project; seismic and liquefaction hazard maps

Science.gov (United States)

Cramer, Chris H.; Bauer, Robert A.; Chung, Jae-won; Rogers, David; Pierce, Larry; Voigt, Vicki; Mitchell, Brad; Gaunt, David; Williams, Robert; Hoffman, David; Hempen, Gregory L.; Steckel, Phyllis; Boyd, Oliver; Watkins, Connor M.; Tucker, Kathleen; McCallister, Natasha

2016-01-01

We present probabilistic and deterministic seismic and liquefaction hazard maps for the densely populated St. Louis metropolitan area that account for the expected effects of surficial geology on earthquake ground shaking. Hazard calculations were based on a map grid of 0.005°, or about every 500 m, and are thus higher in resolution than any earlier studies. To estimate ground motions at the surface of the model (e.g., site amplification), we used a new detailed near‐surface shear‐wave velocity model in a 1D equivalent‐linear response analysis. When compared with the 2014 U.S. Geological Survey (USGS) National Seismic Hazard Model, which uses a uniform firm‐rock‐site condition, the new probabilistic seismic‐hazard estimates document much more variability. Hazard levels for upland sites (consisting of bedrock and weathered bedrock overlain by loess‐covered till and drift deposits), show up to twice the ground‐motion values for peak ground acceleration (PGA), and similar ground‐motion values for 1.0 s spectral acceleration (SA). Probabilistic ground‐motion levels for lowland alluvial floodplain sites (generally the 20–40‐m‐thick modern Mississippi and Missouri River floodplain deposits overlying bedrock) exhibit up to twice the ground‐motion levels for PGA, and up to three times the ground‐motion levels for 1.0 s SA. Liquefaction probability curves were developed from available standard penetration test data assuming typical lowland and upland water table levels. A simplified liquefaction hazard map was created from the 5%‐in‐50‐year probabilistic ground‐shaking model. The liquefaction hazard ranges from low (60% of area expected to liquefy) in the lowlands. Because many transportation routes, power and gas transmission lines, and population centers exist in or on the highly susceptible lowland alluvium, these areas in the St. Louis region are at significant potential risk from seismically induced liquefaction and associated

Hazardous substances in Europe's fresh and marine waters

DEFF Research Database (Denmark)

Collins, Robert; Brack, Werner; Lützhøft, Hans-Christian Holten

Chemicals are an essential part of our daily lives. They are used to produce consumer goods, to protect or restore our health and to boost food production, to name but a few examples — and they are also involved in a growing range of environmental technologies. Europe's chemical and associated...... on their pattern of use and the potential for exposure. Certain types of naturally occurring chemicals, such as metals, can also be hazardous. Emissions of hazardous substances to the environment can occur at every stage of their life cycle, from production, processing, manufacturing and use in downstream...... regarding chemical contamination arising from the exploitation of shale gas has grown recently. Hazardous substances in water affect aquatic life… Hazardous substances are emitted to water bodies both directly and indirectly through a range of diffuse and point source pathways. The presence of hazardous...

Gas processing industrial hygiene needs

International Nuclear Information System (INIS)

D'Orsie, S.M.

1992-01-01

Handling of gases and natural gas liquids provides many opportunities for workers to be exposed to adverse chemical and physical agents. A brief overview of common hazards found in the processing of gas and natural gas liquids is presented in this paper. Suggestions on how an employer can obtain assistance in evaluating his workplace are also presented.presented

The selective generation of acetic acid directly from synthesis gas

International Nuclear Information System (INIS)

Knifton, J.F.

1986-01-01

The authors conclude that each of the ruthenium, cobalt and iodide-containing catalyst components have very specific roles to play in the ''melt'' catalyzed conversion of synthesis gas to acetic acid. C 1 -Oxygenate formation is only observed in the presence of ruthenium carbonyls - [Ru(CO) 3 I 3 ] - is here the dominant species - and there is a direct relationship between liquid yield, ΣOAc - productivity and [Ru(CO) 3 I 3 ] - content. Controlled quantities of iodide ensure that initially formed MeOH is rapidly converted to the more reactive methyl iodide. Subsequent cobalt-catalyzed carbonylation to acetic acid may be preparatively attractive (>80% selectivity, good yields) relative to competing syntheses, where the [Co(CO) 4 ] - concentration is maximized that is, where the Co/Ru ratio is >1, the syngas feedstock is rich in CO, and the initial iodide/cobalt ratios are ca. unity. Formation of cobalt-iodide species appears to be a competing, inhibitory step in this catalysis

75 FR 35366 - Pipeline Safety: Applying Safety Regulation to All Rural Onshore Hazardous Liquid Low-Stress Lines

Science.gov (United States)

2010-06-22

... DEPARTMENT OF TRANSPORTATION Pipeline and Hazardous Materials Safety Administration 49 CFR Part... Onshore Hazardous Liquid Low-Stress Lines AGENCY: Pipeline and Hazardous Materials Safety Administration... to the risks that hazardous liquid and natural gas pipelines pose to the environment. In the Pipeline...

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

Directory of Open Access Journals (Sweden)

Gianfranco Manes

2016-01-01

Full Text Available 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.

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

Science.gov (United States)

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

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

Science.gov (United States)

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

2016-01-20

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.

[Investigation of reference intervals of blood gas and acid-base analysis assays in China].

Science.gov (United States)

Zhang, Lu; Wang, Wei; Wang, Zhiguo

2015-10-01

To investigate and analyze the upper and lower limits and their sources of reference intervals in blood gas and acid-base analysis assays. The data of reference intervals were collected, which come from the first run of 2014 External Quality Assessment (EQA) program in blood gas and acid-base analysis assays performed by National Center for Clinical Laboratories (NCCL). All the abnormal values and errors were eliminated. Data statistics was performed by SPSS 13.0 and Excel 2007 referring to upper and lower limits of reference intervals and sources of 7 blood gas and acid-base analysis assays, i.e. pH value, partial pressure of carbon dioxide (PCO2), partial pressure of oxygen (PO2), Na+, K+, Ca2+ and Cl-. Values were further grouped based on instrument system and the difference between each group were analyzed. There were 225 laboratories submitting the information on the reference intervals they had been using. The three main sources of reference intervals were National Guide to Clinical Laboratory Procedures [37.07% (400/1 079)], instructions of instrument manufactures [31.23% (337/1 079)] and instructions of reagent manufactures [23.26% (251/1 079)]. Approximately 35.1% (79/225) of the laboratories had validated the reference intervals they used. The difference of upper and lower limits in most assays among 7 laboratories was moderate, both minimum and maximum (i.e. the upper limits of pH value was 7.00-7.45, the lower limits of Na+ was 130.00-156.00 mmol/L), and mean and median (i.e. the upper limits of K+ was 5.04 mmol/L and 5.10 mmol/L, the upper limits of PCO2 was 45.65 mmHg and 45.00 mmHg, 1 mmHg = 0.133 kPa), as well as the difference in P2.5 and P97.5 between each instrument system group. It was shown by Kruskal-Wallis method that the P values of upper and lower limits of all the parameters were lower than 0.001, expecting the lower limits of Na+ with P value 0.029. It was shown by Mann-Whitney that the statistic differences were found among instrument

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

International Nuclear Information System (INIS)

Campbell, J.A.; Grant, K.E.; Lucke, R.B.; Clauss, S.A.

1993-01-01

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

Environmental pollution due to gas flaring at Oyigbo area of Rivers State

International Nuclear Information System (INIS)

Avwiri, G. O.; Ebeniro, J. O.

1996-01-01

Environmental degradation due to oil activities in the oil rich Niger Delta of Nigeria is daily approaching a non-tolerance level. Pollutants come from various aspects of operation ranging from seismic operations through drilling to the refinery stage. Gas flared daily by Oil Companies constitute a major health hazard in this country. Environmental pollution due to gas flaring at Oyigbo area of Rivers State is hereby reported. Surface temperature-distance variations were investigated for both dry (March) and rainy (June) seasons. Physical and chemical properties of the rainwater from the areas were also measured and analysed. The results show a surface temperature elevation of about 4.1 Celsius above the mean normal diurnal temperature within a 3.00 km. radius. An average pH 4.25 was recorded thus showing the acidic nature of the environmental rainwater from the area. All other measured parameters showed serious deviations from standards. This temperature elevation and increased acidity of the rainwater have enormous influence on socio-economic lives and the activities of the populace especially on their source of income which is mainly small scale farming. It is therefore necessary that Government agencies empowered to monitor environment especially FEPA should implement all the existing legislation on gas flaring and be more involved in the design and location of gas flaring stacks. These stacks should be located at least 2 km. from towns and villages

Impact of scaling on the nitric-glycolic acid flowsheet

Energy Technology Data Exchange (ETDEWEB)

Lambert, D. [Savannah River Site (SRS), Aiken, SC (United States)

2016-02-01

Savannah River Remediation (SRR) is considering using glycolic acid as a replacement for formic acid in Sludge Receipt and Adjustment Tank (SRAT) processing in the Defense Waste Processing Facility (DWPF). Catalytic decomposition of formic acid is responsible for the generation of hydrogen, a potentially flammable gas, during processing. To prevent the formation of a flammable mixture in the offgas, an air purge is used to dilute the hydrogen concentration below the 60% of the Composite Lower Flammability Limit (CLFL). The offgas is continuously monitored for hydrogen using Gas Chromatographs (GCs). Since formic acid is much more volatile and toxic than glycolic acid, a formic acid spill would lead to the release of much larger quantities to the environment. Switching from formic acid to glycolic acid is expected to eliminate the hydrogen flammability hazard leading to lower air purges, thus downgrading of Safety Significant GCs to Process Support GCs, and minimizing the consequence of a glycolic acid tank leak in DWPF. Overall this leads to a reduction in process operation costs and an increase in safety margin. Experiments were completed at three different scales to demonstrate that the nitric-glycolic acid flowsheet scales from the 4-L lab scale to the 22-L bench scale and 220-L engineering scale. Ten process demonstrations of the sludge-only flowsheet for SRAT and Slurry Mix Evaporator (SME) cycles were performed using Sludge Batch 8 (SB8)-Tank 40 simulant. No Actinide Removal Process (ARP) product or strip effluent was added during the runs. Six experiments were completed at the 4-L scale, two experiments were completed at the 22-L scale, and two experiments were completed at the 220-L scale. Experiments completed at the 4-L scale (100 and 110% acid stoichiometry) were repeated at the 22-L and 220-L scale for scale comparisons.

Risk factors for hazardous events in olfactory-impaired patients.

Science.gov (United States)

Pence, Taylor S; Reiter, Evan R; DiNardo, Laurence J; Costanzo, Richard M

2014-10-01

Normal olfaction provides essential cues to allow early detection and avoidance of potentially hazardous situations. Thus, patients with impaired olfaction may be at increased risk of experiencing certain hazardous events such as cooking or house fires, delayed detection of gas leaks, and exposure to or ingestion of toxic substances. To identify risk factors and potential trends over time in olfactory-related hazardous events in patients with impaired olfactory function. Retrospective cohort study of 1047 patients presenting to a university smell and taste clinic between 1983 and 2013. A total of 704 patients had both clinical olfactory testing and a hazard interview and were studied. On the basis of olfactory function testing results, patients were categorized as normosmic (n = 161), mildly hyposmic (n = 99), moderately hyposmic (n = 93), severely hyposmic (n = 142), and anosmic (n = 209). Patient evaluation including interview, examination, and olfactory testing. Incidence of specific olfaction-related hazardous events (ie, burning pots and/or pans, starting a fire while cooking, inability to detect gas leaks, inability to detect smoke, and ingestion of toxic substances or spoiled foods) by degree of olfactory impairment. The incidence of having experienced any hazardous event progressively increased with degree of impairment: normosmic (18.0%), mildly hyposmic (22.2%), moderately hyposmic (31.2%), severely hyposmic (32.4%), and anosmic (39.2%). Over 3 decades there was no significant change in the overall incidence of hazardous events. Analysis of demographic data (age, sex, race, smoking status, and etiology) revealed significant differences in the incidence of hazardous events based on age (among 397 patients hazardous event, vs 31 of 146 patients ≥65 years [21.3%]; P hazardous event, vs 73 of 265 men [27.6%]; P = .009), and race (among 98 African Americans, 41 [41.8%] with hazardous event, vs 134 of 434 whites [30.9%]; P = .04

Classification of coal seam outburst hazards and evaluation of the importance of influencing factors

OpenAIRE

Shi Xianzhi; Song Dazhao; Qian Ziwei

2017-01-01

Coal and gas outbursts are the result of several geological factors related to coal seam gas (coal seam gas pressure P, coal seam sturdiness coefficient f and coal seam gas content W), and these parameters can be used to classify the outburst hazard level of a coal seam.

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

DEFF Research Database (Denmark)

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...

N2 gas station and gas distribution system for TLD personnel monitoring gas based semi-automatic badge readers

International Nuclear Information System (INIS)

Chourasiya, G.; Pradhan, S.M.; Kher, R.K.; Bhatt, B.C

2003-01-01

Full text: New improvised hot gas based Auto TLD badge reader has several advantages over the earlier contact heating based manual badge reader. It requires constant supply of N 2 gas for its operation; The gas supplied using replaceable individual gas cylinders may have some safety hazards in their handling. It was therefore considered worthwhile to setup a N 2 gas assembly/ station outside the lab area and to bring regulated gas supply through network of tubes with proper regulation to the individual readers. The paper presents detailed description of the gas station and distribution system. The system is quite useful and offers several practical advantages for readout of TLD badges on the semiautomatic badge readers based on gas heating. Important advantage from dosimetric point of view is avoidance of gas flow rate fluctuations and corresponding variations in TL readouts

24 CFR Appendix I to Subpart C of... - Specific Hazardous Substances

Science.gov (United States)

2010-04-01

... Ketone Naptha Pentane Propylene Oxide Toluene Vinyl Acetate Xylene Hazardous Gases Acetaldehyde Butadiene Butane Ethene Ethylene Ethylene Oxide Hydrogen Liquefied Natural Gas (LNG) Liquefied Petroleum Gas (LPG... Commercial/Industrial Facilities,” by Rolf Jensen and Associates, Inc., April 1982) [49 FR 5105, Feb. 10...

[Determination of naphthenic acids in distillates of crude oil by gas chromatography/chemical ionization-mass spectrometry].

Science.gov (United States)

Lü, Zhenbo; Tian, Songbai; Zhai, Yuchun; Sun, Yanwei; Zhuang, Lihong

2004-05-01

The petroleum carboxylic acids in 200-420 degrees C distillate of crude oil were separated by the extraction with column chromatography on an anion exchange resin. The effect of the composition and structure of naphthenic acids on separation were studied by the infra-red (IR) spectroscopic techniques. Naphthenic acids and iso-butane reagent gas were introduced into the ion source for chemical ionization, in which the ions represented by [M + C4H9]+ were used to calculate the relative molecular mass for each acid. Based on the mass spectra of pure fatty and naphthenic acids, in combination with the z-series formula CnH(2n + z)O2, the naphthenic acids can be classified into fatty, mono-, bi- ... hexa-cyclic types. The results indicated that the relative molecular mass range of naphthenic acids in this distillates was 170-510, and the carbon number range was C10-C35. The contents of bi-cyclic and tri-cyclic naphthenic acids were higher than others.

A dynamic approach for the impact of a toxic gas dispersion hazard considering human behaviour and dispersion modelling.

Science.gov (United States)

Lovreglio, Ruggiero; Ronchi, Enrico; Maragkos, Georgios; Beji, Tarek; Merci, Bart

2016-11-15

The release of toxic gases due to natural/industrial accidents or terrorist attacks in populated areas can have tragic consequences. To prevent and evaluate the effects of these disasters different approaches and modelling tools have been introduced in the literature. These instruments are valuable tools for risk managers doing risk assessment of threatened areas. Despite the significant improvements in hazard assessment in case of toxic gas dispersion, these analyses do not generally include the impact of human behaviour and people movement during emergencies. This work aims at providing an approach which considers both modelling of gas dispersion and evacuation movement in order to improve the accuracy of risk assessment for disasters involving toxic gases. The approach is applied to a hypothetical scenario including a ship releasing Nitrogen dioxide (NO2) on a crowd attending a music festival. The difference between the results obtained with existing static methods (people do not move) and a dynamic approach (people move away from the danger) which considers people movement with different degrees of sophistication (either a simple linear path or more complex behavioural modelling) is discussed. Copyright © 2016 Elsevier B.V. All rights reserved.

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

International Nuclear Information System (INIS)

Osuteye, I.

2015-01-01

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

Retrofit acid gas emission control for municipal waste incineration application of dry sorbent injection

International Nuclear Information System (INIS)

Zmuda, J.T.; Smith, P.V.

1991-01-01

Dry sorbent injection (DSI) has been successfully demonstrated on coal fired boiler applications as a means of reducing sulfur dioxide emissions. More recently, the dry sorbent injection process was applied to an existing municipal waste incinerator to provide acid gas emission controls. The results obtained from the successful demonstration of the sorbent injection system on an existing municipal incinerator are presented. Removal efficiencies of compounds such as HCl, SO 2 , SO 3 , mercury, and others by the use of sorbent injection are shown. Effects of the DSI system on downstream equipment, such as electrostatic precipitators, fabric filters, ash handling systems, and waste management is included. The impacts of the DSI system on the furnace is also discussed. In this paper a discussion of dry sorbent injection as a means of reducing acid gas and other emissions from existing municipal waste incinerators which may be affected by the regulations is presented. An application case study will outline typical exhaust conditions, expected pollution reductions, capital and operating costs, and type of available sorbents and their costs

Hazardous waste operational plan for site 300

International Nuclear Information System (INIS)

Roberts, R.S.

1982-01-01

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

Characterization of condensed phase nitric acid particles formed in the gas phase

Institute of Scientific and Technical Information of China (English)

Long Jia; Yongfu Xu

2011-01-01

The formation of nitric acid hydrates has been observed in a chamber during the dark reaction of NO2 with O3 in the presence of air.The size of condensed phase nitric acid was measured to be 40-100 nm and 20-65 nm at relative humidity (RH) ≤ 5％ and RH = 67％ under our experimental conditions, respectively.The nitric acid particles were collected on the glass fiber membrane and their chemical compositions were analyzed by infrared spectrum.The main components of nitric acid hydrates in particles are HNO3·3H2O and NO3-·xH2O (x≥ 4) at low RH, whereas at high RH HNO3·H2O, HNO3·2H2O, HNO3·3H2O and NO3-·xH2O (x≥ 4) all exist in the condensed phase.At high RH HNO3·xH2O (x ≤ 3) collected on the glass fiber membrane is greatly increased, while NO3-·xH2O (x ≥4) decreased, compared with low RH.To the best of our knowledge, this is the first time to report that condensed phase nitric acid can be generated in the gas phase at room temperature.

75 FR 5244 - Pipeline Safety: Integrity Management Program for Gas Distribution Pipelines; Correction

Science.gov (United States)

2010-02-02

... Management Program for Gas Distribution Pipelines; Correction AGENCY: Pipeline and Hazardous Materials Safety... DEPARTMENT OF TRANSPORTATION Pipeline and Hazardous Materials Safety Administration 49 CFR Part... Regulations to require operators of gas distribution pipelines to develop and implement integrity management...

Fast derivatization of fatty acids in different meat samples for gas chromatography analysis.

Science.gov (United States)

Figueiredo, Ingrid Lima; Claus, Thiago; Oliveira Santos Júnior, Oscar; Almeida, Vitor Cinque; Magon, Thiago; Visentainer, Jesuí Vergilio

2016-07-22

In order to analyze the composition of fatty acids employing gas chromatography as the separation method, a derivatization of lipids using esterification and transesterification reactions is needed. The methodologies currently available are time consuming and use large amounts of sample and reagents. Thus, this work proposes a new procedure to carry out the derivatization of fatty acids without the need for prior extraction of lipids. The use of small amounts of sample (100mg) allows the analysis to be performed in specific parts of animals, in most cases without having them slaughtered. Another benefit is the use of small amounts of reagents (only 2mL of NaOH/Methanol and H2SO4/Methanol). The use of an experimental design procedure (Design Expert software) allows the optimization of the alkaline and acid reaction times. The procedure was validated for five minutes in both steps. The method was validated for bovine fat, beef, chicken, pork, fish and shrimp meats. The results for the merit figures of accuracy (from 101.07% to 109.18%), precision (RSDintra-day (from 0.65 to 3.93%), RSDinter-day (from 1.57 to 5.22%)), linearity (R(2)=0.9864) and robustness confirmed that the new method is satisfactory within the linear range of 2-30% of lipids in the sample. Besides the benefits of minimizing the amount of samples and reagents, the procedure enables gas chromatography sample preparation in a very short time compared with traditional procedures. Copyright © 2016 Elsevier B.V. All rights reserved.

Living with geo-resources and geo-hazards

NARCIS (Netherlands)

Hangx, Suzanne|info:eu-repo/dai/nl/30483579X; Niemeijer, André|info:eu-repo/dai/nl/370832132

2015-01-01

Two of the key strategic topics on the European Committee’s Horizon2020 Roadmap revolve around geo-resources and geo-hazards, and their impact on societal and economic development. On the way towards a better policy for sustainable geo-resources production, such as oil, gas, geothermal energy and

76 FR 25576 - Pipeline Safety: Applying Safety Regulations to All Rural Onshore Hazardous Liquid Low-Stress Lines

Science.gov (United States)

2011-05-05

... DEPARTMENT OF TRANSPORTATION Pipeline and Hazardous Materials Safety Administration 49 CFR Part... to All Rural Onshore Hazardous Liquid Low-Stress Lines AGENCY: Pipeline and Hazardous Materials..., suggested that the scope should include low-stress gas pipelines such as those associated with coal bed...

Gas-phase ion/ion reactions of peptides and proteins: acid/base, redox, and covalent chemistries.

Science.gov (United States)

Prentice, Boone M; McLuckey, Scott A

2013-02-01

Gas-phase ion/ion reactions are emerging as useful and flexible means for the manipulation and characterization of peptide and protein biopolymers. Acid/base-like chemical reactions (i.e., proton transfer reactions) and reduction/oxidation (redox) reactions (i.e., electron transfer reactions) represent relatively mature classes of gas-phase chemical reactions. Even so, especially in regards to redox chemistry, the widespread utility of these two types of chemistries is undergoing rapid growth and development. Additionally, a relatively new class of gas-phase ion/ion transformations is emerging which involves the selective formation of functional-group-specific covalent bonds. This feature details our current work and perspective on the developments and current capabilities of these three areas of ion/ion chemistry with an eye towards possible future directions of the field.

RPC gas recovery by open loop method

Energy Technology Data Exchange (ETDEWEB)

Joshi, Avinash [Alpha Pneumatics, 11, Krishna Kutir, Madanlal Dhigra Road, Panch Pakhadi (India)], E-mail: alpha_pneumatics@hotmail.com

2009-05-01

RPC detectors require to be flushed with small but continuous flow of gas mixture. Dealing with large number of detectors, gas consumption to very large volumes. Gas flow is a running expense and constituent gases are too expensive to be treated as consumables. Exhaust gas mixture from detectors is a potential environmental hazard if discharged directly into the atmosphere. Storage of gases on a large scale also leads to inventory- and safety-related problems. A solution to these problems is the recovery and reuse of exhaust gas mixture from RPC detectors. Close loop method employs recirculation of exhausted gas mixture after purification, analysis and addition of top-up quantities. In open loop method, under consideration here, individual component gases are separated from gas mixture and reused as source. During open loop process, gases liquefiable at low pressures are separated from ones liquefiable at high pressure. The gas phase components within each group are successively separated by either fractional condensation or gravity separation. Gas mixture coming from RPC exhaust is first desiccated by passage through molecular sieve adsorbent type (3A+4A). Subsequent scrubbing over basic activated alumina removes toxic and acidic contaminants such as S{sub 2}F{sub 10} produced during corona (arcing) discharge. In the first stage of separation isobutane and freon are concentrated by diffusion and liquefied by fractional condensation by cooling upto -30 deg. C. Liquefied gases are returned to source tanks. In the second stage of separation, argon and sulphur hexafluoride, the residual gases, are concentrated by settling due to density difference. SF{sub 6} is stored for recovery by condensation at high pressure while argon is further purified by thermal cracking of crossover impurities at 1000 deg. C followed by wet scrubbing.

RPC gas recovery by open loop method

International Nuclear Information System (INIS)

Joshi, Avinash

2009-01-01

RPC detectors require to be flushed with small but continuous flow of gas mixture. Dealing with large number of detectors, gas consumption to very large volumes. Gas flow is a running expense and constituent gases are too expensive to be treated as consumables. Exhaust gas mixture from detectors is a potential environmental hazard if discharged directly into the atmosphere. Storage of gases on a large scale also leads to inventory- and safety-related problems. A solution to these problems is the recovery and reuse of exhaust gas mixture from RPC detectors. Close loop method employs recirculation of exhausted gas mixture after purification, analysis and addition of top-up quantities. In open loop method, under consideration here, individual component gases are separated from gas mixture and reused as source. During open loop process, gases liquefiable at low pressures are separated from ones liquefiable at high pressure. The gas phase components within each group are successively separated by either fractional condensation or gravity separation. Gas mixture coming from RPC exhaust is first desiccated by passage through molecular sieve adsorbent type (3A+4A). Subsequent scrubbing over basic activated alumina removes toxic and acidic contaminants such as S 2 F 10 produced during corona (arcing) discharge. In the first stage of separation isobutane and freon are concentrated by diffusion and liquefied by fractional condensation by cooling upto -30 deg. C. Liquefied gases are returned to source tanks. In the second stage of separation, argon and sulphur hexafluoride, the residual gases, are concentrated by settling due to density difference. SF 6 is stored for recovery by condensation at high pressure while argon is further purified by thermal cracking of crossover impurities at 1000 deg. C followed by wet scrubbing.

Off-gas characteristics of defense waste vitrification using liquid-fed Joule-heated ceramic melters

International Nuclear Information System (INIS)

Goles, R.W.; Sevigny, G.J.

1983-09-01

Off-gas and effluent characterization studies have been established as part of a PNL Liquid-Fed Ceramic Melter development program supporting the Savannah River Laboratory Defense Waste Processing Facility (SRL-DWPF). The objectives of these studies were to characterize the gaseous and airborne emission properties of liquid-fed joule-heated melters as a function of melter operational parameters and feed composition. All areas of off-gas interest and concern including effluent characterization, emission control, flow rate behavior and corrosion effects have been studied using alkaline and formic-acid based feed compositions. In addition, the behavioral patterns of gaseous emissions, the characteristics of melter-generated aerosols and the nature and magnitude of melter effluent losses have been established under a variety of feeding conditions with and without the use of auxiliary plenum heaters. The results of these studies have shown that particulate emissions are responsible for most radiologically important melter effluent losses. Melter-generated gases have been found to be potentially flammable as well as corrosive. Hydrogen and carbon monoxide present the greatest flammability hazard of the combustibles produced. Melter emissions of acidic volatile compounds of sulfur and the halogens have been responsible for extensive corrosion observed in melter plenums and in associated off-gas lines and processing equipment. The use of auxiliary plenum heating has had little effect upon melter off-gas characteristics other than reducing the concentrations of combustibles

A review of accidents, prevention and mitigation options related to hazardous gases

International Nuclear Information System (INIS)

Fthenakis, V.M.

1993-05-01

Statistics on industrial accidents are incomplete due to lack of specific criteria on what constitutes a release or accident. In this country, most major industrial accidents were related to explosions and fires of flammable materials, not to releases of chemicals into the environment. The EPA in a study of 6,928 accidental releases of toxic chemicals revealed that accidents at stationary facilities accounted for 75% of the total number of releases, and transportation accidents for the other 25%. About 7% of all reported accidents (468 cases) resulted in 138 deaths and 4,717 injuries ranging from temporary respiratory problems to critical injuries. In-plant accidents accounted for 65% of the casualties. The most efficient strategy to reduce hazards is to choose technologies which do not require the use of large quantities of hazardous gases. For new technologies this approach can be implemented early in development, before large financial resources and efforts are committed to specific options. Once specific materials and options have been selected, strategies to prevent accident initiating events need to be evaluated and implemented. The next step is to implement safety options which suppress a hazard when an accident initiating event occurs. Releases can be prevented or reduced with fail-safe equipment and valves, adequate warning systems and controls to reduce and interrupt gas leakage. If an accident occurs and safety systems fail to contain a hazardous gas release, then engineering control systems will be relied on to reduce/minimize environmental releases. As a final defensive barrier, the prevention of human exposure is needed if a hazardous gas is released, in spite of previous strategies. Prevention of consequences forms the final defensive barrier. Medical facilities close by that can accommodate victims of the worst accident can reduce the consequences of personnel exposure to hazardous gases

IRIS Toxicological Review of Trichloroacetic Acid (TCA) ...

Science.gov (United States)

EPA is conducting a peer review and public comment of the scientific basis supporting the human health hazard and dose-response assessment of Trichloroacetic acid (TCA) that when finalized will appear on the Integrated Risk Information System (IRIS) database. The draft Toxicological Review of trichloroacetic acid provides scientific support and rationale for the hazard and dose-response assessment pertaining to chronic exposure to trichloroacetic acid.

At-line gas chromatographic-mass spectrometric analysis of fatty acid profiles of green microalgae using a direct thermal desorption interface

NARCIS (Netherlands)

Blokker, P.; Pel, R.; Akoto, L.; Udo, A.; Brinkman, U.A.Th.; Vreuls, R.J.J.

2002-01-01

Thermally assisted hydrolysis and methylation¯gas chromatography (THM¯GC) is an important tool to analyse fatty acid in complex matrices. Since THM¯GC has major drawbacks such as isomerisation when applied to fatty acids in natural matrices, a direct thermal desorption (DTD) interface and an

The Impact Hazard in the Context of Other Natural Hazards and Predictive Science

Science.gov (United States)

Chapman, C. R.

1998-09-01

The hazard due to impact of asteroids and comets has been recognized as analogous, in some ways, to other infrequent but consequential natural hazards (e.g. floods and earthquakes). Yet, until recently, astronomers and space agencies have felt no need to do what their colleagues and analogous agencies must do in order the assess, quantify, and communicate predictions to those with a practical interest in the predictions (e.g. public officials who must assess the threats, prepare for mitigation, etc.). Recent heightened public interest in the impact hazard, combined with increasing numbers of "near misses" (certain to increase as Spaceguard is implemented) requires that astronomers accept the responsibility to place their predictions and assessments in terms that may be appropriately considered. I will report on preliminary results of a multi-year GSA/NCAR study of "Prediction in the Earth Sciences: Use and Misuse in Policy Making" in which I have represented the impact hazard, while others have treated earthquakes, floods, weather, global climate change, nuclear waste disposal, acid rain, etc. The impact hazard presents an end-member example of a natural hazard, helping those dealing with more prosaic issues to learn from an extreme. On the other hand, I bring to the astronomical community some lessons long adopted in other cases: the need to understand the policy purposes of impact predictions, the need to assess potential societal impacts, the requirements to very carefully assess prediction uncertainties, considerations of potential public uses of the predictions, awareness of ethical considerations (e.g. conflicts of interest) that affect predictions and acceptance of predictions, awareness of appropriate means for publicly communicating predictions, and considerations of the international context (especially for a hazard that knows no national boundaries).

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

Energy Technology Data Exchange (ETDEWEB)

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.

Stereometabolism of ethylbenzene in man: gas chromatographic determination of urinary excreted mandelic acid enantiomers and phenylglyoxylic acid and their relation to the height of occupational exposure.

Science.gov (United States)

Korn, M; Gfrörer, W; Herz, R; Wodarz, I; Wodarz, R

1992-01-01

Ethylbenzene is an important industrial solvent and a key substance in styrene production. Ethylbenzene metabolism leads to the formation of mandelic acid, which occurs in two enantiomeric forms, and phenylglyoxylic acid. To decide which enantiomer is preferably formed, 70 urine samples of exposed workers were taken at the end of shifts and--after 3-pentyl ester derivatisation--gas chromatographically analysed. The R/S ratio of mandelic acid enantiomers in urine amounts to 19:1, which means that R-mandelic acid is a major metabolite and S-mandelic acid is one of the minor urinary metabolites of ethylbenzene in man. The R/S ratio is independent of ambient air concentration of ethylbenzene within the investigated range. Compared to an ethylbenzene monoexposure the height of total mandelic acid excretion is decreased in the case of coexposure to other aromatic solvents.

Conditions for a partial summation of SO2 and NO2 hazardous effect in gas emission regulations

Science.gov (United States)

Sokolov, A. K.

2017-12-01

In order to provide environmental safety, the concentrations of SO2 and SO2 in the surface layer of atmospheric air should not exceed corresponding one-time values accepted for maximum permissible concentrations (MPCs). The only document that provides a normative calculation of hazardous substance dispersion in the atmospheric air up to the present time is presented by regulations OND-86. It has established that, in taking into account the summation (unidirectionality) of hazardous action of substances (including SO2 and NO2 gases), the sum of their relative concentrations should not exceed unity. A novel standard GN 2.1.6.2326-08 stipulates that "nitrogen dioxide and sulfur dioxide have a partial summation of action; therefore the sum of their relative concentrations should not exceed 1.6." This paper is devoted to analyzing the calculation of the summation of action for SO2 and NO2 gases and proving that the condition established in GN 2.1.6.2326-08 is not quite correct. According to the condition required by standard GN 2.1.6.2326-08, it turns out that, for some combinations of concentrations, the hazardous effect of gases is not added together, but one gas compensates an effect of the other, which contradicts the points of OND-86. For example, at SO2 and NO2 concentrations amounting to 0.6 and 0.04, respectively, the condition required by standard GN 2.1.6.2326-08 is satisfied, although the concentration of SO2 exceeds a normatively fixed value of MPC = 0.5. The graphical analysis of a concentration region for SO2 and NO2 gases clearly shows the areas where the condition required by standard GN 2.1.6.2326-08 is satisfied, but the environmental safety according to OND-86 is not provided. Recommendations are proposed for the correction of requirements established by standard GN 2.1.6.2326-08.

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

Energy Technology Data Exchange (ETDEWEB)

Varanusupakul, Pakorn [Chromatography and Separation Research Unit, Department of Chemistry, Faculty of Science, Chulalongkorn University, Phayathai Road, Patumwan, Bangkok 10330 (Thailand)], E-mail: pakorn.v@chula.ac.th; Vora-adisak, Narongchai; Pulpoka, Bancha [Chromatography and Separation Research Unit, Department of Chemistry, Faculty of Science, Chulalongkorn University, Phayathai Road, Patumwan, Bangkok 10330 (Thailand)

2007-08-15

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% Na{sub 2}SO{sub 4}. The linear calibration curves were observed for the concentrations ranging from 1 to 300 {mu}g L{sup -1} with the correlation coefficients (R{sup 2}) being greater than 0.99. The method detection limits of most analytes were below 1 {mu}g L{sup -1} except DCAA and MCAA that were 2 and 18 {mu}g L{sup -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.

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

International Nuclear Information System (INIS)

Varanusupakul, Pakorn; Vora-adisak, Narongchai; Pulpoka, Bancha

2007-01-01

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% Na 2 SO 4 . The linear calibration curves were observed for the concentrations ranging from 1 to 300 μg L -1 with the correlation coefficients (R 2 ) 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

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

NARCIS (Netherlands)

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

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

NARCIS (Netherlands)

Akoto, L.; Vreuls, 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

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

NARCIS (Netherlands)

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

Thermodynamic modeling of acidic gas solubility in aqueous solutions of MEA, MDEA and MEA-MDEA blends

DEFF Research Database (Denmark)

Vrachnos, Ath.; Kontogeorgis, Georgios; Voutsas, EC

2006-01-01

and extended in this study to the absorption of carbon dioxide into aqueous monoethanolamine (MEA) solutions and aqueous MDEA-MEA blends. The results of the model are compared with experimental data taken from the literature. Very satisfactory predictions of acidic gas vapor-liquid equilibrium over MDEA, MEA...

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

International Nuclear Information System (INIS)

LaVerne, J.A.

1998-01-01

'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

The hazard to man of accidental releases of tritium

International Nuclear Information System (INIS)

Brearley, I.R.

1985-03-01

Some aspects of the atmospheric dispersion of tritium are discussed, followed by consideration of the dosimetric pathways. In order to assess the significance of a tritium release the doses from various pathways are estimated and compared with the doses estimated from a similar release of iodine-131. The major hazard from tritium is the ingestion of contaminated food products. For similar releases of tritium and I 131 the ingestion hazard can be comparable if the release occurs near and before the end of the harvest season. However, in the tritium release case the agricultural season influences the consequences markedly and, at other times during the year, the ingestion hazard from tritium may be approximately 20 times less. The dose from inhalation of tritium is sensitive to its chemical form and for similar releases of tritiated water and tritium gas then the dose from tritiated water is approximately 10 4 greater than the dose from tritium gas. For similar releases of tritiated water and iodine-131 then a comparison of the inhalation shows that the dose from the iodine is approximately 300 times greater. (author)

78 FR 65427 - Pipeline Safety: Reminder of Requirements for Liquefied Petroleum Gas and Utility Liquefied...

Science.gov (United States)

2013-10-31

... DEPARTMENT OF TRANSPORTATION Pipeline and Hazardous Materials Safety Administration [Docket No. PHMSA-2013-0097] Pipeline Safety: Reminder of Requirements for Liquefied Petroleum Gas and Utility Liquefied Petroleum Gas Pipeline Systems AGENCY: Pipeline and Hazardous Materials Safety Administration...

Instrumentation for Detecting Hazardous Materials.

Science.gov (United States)

1980-06-01

equipment a detector for monitoring radioactivity . A portable device for detecting the presence of hazardous mate- rials should also be included in the...Acrylonitrile 2 Natural Gas/LNG 2 211 ----- Material Name (Cont’d.) Number of Times Listed Radioactive Materials 2 Fertilizers 1 Cellulose Nitrate 1 Acrolein...Birnbaum, and Curtis Fincher, L "Fluorescence Determination of the Atmospheric Polutant NO2 in Impact of Lasers in Spectroscopy, Vol. 49 of Proceed

Acidic methanolysis v. alkaline saponification in gas chromatographic characterization of mycobacteria: differentiation between Mycobacterium avium-intracellulare and Mycobacterium gastri.

Science.gov (United States)

Larsson, L

1983-08-01

Mycobacterium avium-intracellulare and M.gastri were analyzed with capillary gas chromatography after each strain had been subjected to acidic methanolysis or to alkaline saponification followed by methylation. Prominent peaks of myristic, palmitoleic, palmitic, oleic, stearic and tuberculostearic acids were found in the chromatograms of both species, whereas 2-octadecanol and 2-eicosanol were detected only in M. avium-intracellulare. In initial runs, both of the derivatization principles yielded virtually identical chromatograms for a given strain. After repeated injections of extracts from alkaline saponification, however, the alcohol peaks showed pronounced tailing and finally almost disappeared from the chromatograms. This disadvantage, which was not observed when only acid methanolysis was used, could be overcome with trifluoroacetylation. Restored peak shape of the underivatized alcohols could be achieved by washing the cross-linked stationary phase in the capillary tubing with organic solvents. The study demonstrated the importance of conditions which enable separation of 2-octadecanol and 2-eicosanol when gas chromatography is used for species identification of mycobacteria.

Simultaneous measurements of formaldehyde and nitrous acid in dews and gas phase in the atmosphere of Santiago, Chile

Science.gov (United States)

Rubio, María A.; Lissi, Eduardo; Villena, Guillermo; Elshorbany, Y. F.; Kleffmann, Jörg; Kurtenbach, Ralf; Wiesen, Peter

2009-12-01

The amounts of formaldehyde and nitrous acid (HONO) in gas phase and dews of Santiago de Chile were simultaneously measured. Formaldehyde concentrations values in the liquid phase (dews) correlate fairly well with those in the gaseous phase and are even higher than those expected from gas-dew equilibrium. On the other hand, nitrite concentrations in dews were considerably smaller (ca. 15 times) than those expected from the gas-phase concentrations. This under-saturation is attributed to diffusion limitations due to the relatively large HONO solubility. In agreement with this, under-saturation increases with the rate of dew formation and the pH of the collected waters, factors that should increase the rate of gas to liquid HONO transfer required to reach equilibrium.

Changes in monosaccharides, organic acids and amino acids during Cabernet Sauvignon wine ageing based on a simultaneous analysis using gas chromatography-mass spectrometry.

Science.gov (United States)

Zhang, Xin-Ke; Lan, Yi-Bin; Zhu, Bao-Qing; Xiang, Xiao-Feng; Duan, Chang-Qing; Shi, Ying

2018-01-01

Monosaccharides, organic acids and amino acids are the important flavour-related components in wines. The aim of this article is to develop and validate a method that could simultaneously analyse these compounds in wine based on silylation derivatisation and gas chromatography-mass spectrometry (GC-MS), and apply this method to the investigation of the changes of these compounds and speculate upon their related influences on Cabernet Sauvignon wine flavour during wine ageing. This work presented a new approach for wine analysis and provided more information concerning red wine ageing. This method could simultaneously quantitatively analyse 2 monosaccharides, 8 organic acids and 13 amino acids in wine. A validation experiment showed good linearity, sensitivity, reproducibility and recovery. Multiple derivatives of five amino acids have been found but their effects on quantitative analysis were negligible, except for methionine. The evolution pattern of each category was different, and we speculated that the corresponding mechanisms involving microorganism activities, physical interactions and chemical reactions had a great correlation with red wine flavours during ageing. Simultaneously quantitative analysis of monosaccharides, organic acids and amino acids in wine was feasible and reliable and this method has extensive application prospects. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

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

International Nuclear Information System (INIS)

Yamaguchi, Masaru; Ebina, Satoko; Kashiwakura, Ikuo

2013-01-01

Arterial cord blood (CB) acid-base status and gas values, such as pH, PCO 2 , PO 2 , HCO 3 - 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 PCO 2 and HCO 3 - 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 PCO 2 . Moreover, the surviving fraction of BFU-E showed a significant negative correlation with gestational age. Thus, HSPCs obtained from CB with high PCO 2 /HCO 3 - levels were sensitive to X-irradiation, which suggests that the status of arterial PCO 2 /HCO 3 - influences the radiosensitivity of fetal/neonatal hematopoiesis, especially erythropoiesis. (author)

Gas Antisolvent Approach for the Precipitation of α -Methoxyphenylacetic Acid – ( R -1-Cyclohexylethylamine Diateromeric Salt

Directory of Open Access Journals (Sweden)

A. Zodge

2017-10-01

Full Text Available One of the major drawbacks of diastereomeric salt precipitation based enantioseparation is the time and solvent requirement of crystallization. In the gas antisolvent (GAS approach, supercritical carbon dioxide is applied as an antisolvent, and the precipitation takes place in a couple of minutes. By setting the process parameters diastereomeric excess, yields, and selectivity can be controlled. Applicability of the process is demonstrated on the resolution of racemic 2-methoxyphenylacetic acid with enantiopure (R-(−-1-cyclohexylethylamine. Diastereomeric excess values over 55 % along with 80 % yields were achieved at optimal conditions in a single step.

Gas phase hydrolysis of formaldehyde to form methanediol: impact of formic acid catalysis.

Science.gov (United States)

Hazra, Montu K; Francisco, Joseph S; Sinha, Amitabha

2013-11-21

We find that formic acid (FA) is very effective at facilitating diol formation through its ability to reduce the barrier for the formaldehyde (HCHO) hydrolysis reaction. The rate limiting step in the mechanism involves the isomerization of a prereactive collision complex formed through either the HCHO···H2O + FA and/or HCHO + FA···H2O pathways. The present study finds that the effective barrier height, defined as the difference between the zero-point vibrational energy (ZPE) corrected energy of the transition state (TS) and the HCHO···H2O + FA and HCHO + FA···H2O starting reagents, are respectively only ∼1 and ∼4 kcal/mol. These barriers are substantially lower than the ∼17 kcal/mol barrier associated with the corresponding step in the hydrolysis of HCHO catalyzed by a single water molecule (HCHO + H2O + H2O). The significantly lower barrier heights for the formic acid catalyzed pathway reveal a new important role that organic acids play in the gas phase hydrolysis of atmospheric carbonyl compounds.

Hazardous waste systems analysis at Los Alamos National Laboratory

International Nuclear Information System (INIS)

Urioste, J.

1997-01-01

Los Alamos National Laboratory produces routine and non-routine hazardous waste as a by-product of mission operations. Hazardous waste commonly generated at the Laboratory includes many types of laboratory research chemicals, solvents, acids, bases, carcinogens, compressed gases, metals, and other solid waste contaminated with hazardous waste. The Los Alamos National Laboratory Environmental Stewardship Office has established a Hazardous Waste Minimization Coordinator to specifically focus on routine and non-routine RCRA, TSCA, and other administratively controlled wastes. In this process, the Waste Minimization Coordinator has developed and implemented a systems approach to define waste streams, estimate waste management costs and develop plans to implement avoidance practices, and develop projects to reduce or eliminate the waste streams at the Laboratory. The paper describes this systems approach

Radon-hazard potential the Beaver basin, Utah

International Nuclear Information System (INIS)

Bishop, C.E.

1995-01-01

Indoor-radon levels in the Beaver basin of southwestern Utah are the highest recorded to date in Utah, ranging from 17.5 to 495 picocuries per liter (pCi/L). Because the U.S. Environment Protection Agency considers indoor-radon levels above 4 pCi/L to represent a risk of lung cancer from long-term exposure, the Utah Geological Survey is preparing a radon-hazard-potential map for the area to help prioritize indoor testing and evaluate the need for radon-resistant construction. Radon is a chemically inert radioactive gas derived from the decay of uranium-238, which is commonly found in rocks and soils. Soil permeability, depth to ground water, and uranium/thorium content of source materials control the mobility and concentration of radon in the soil. Once formed, radon diffuses into the pore space of the soil and then to the atmosphere or into buildings by pressure-driven flow of air or additional diffusion. The Beaver basin has been a topographic and structural depression since late Miocene time. Paleocene to Miocene volcanic and igneous rocks border the basin. Uraniferous alluvial-fan, piedmont-slope, flood-plain, and lacustrine sediments derived from the surrounding volcanic rocks fill the basin. A soil-gas radon and ground radioactivity survey in the Beaver basin shows that soils have high levels of radon gas. In this survey, uranium concentrations range from 3 to 13 parts per million (ppm) and thorium concentrations range from 10 to 48 ppm. Radon concentrations in the soil gas ranged from 85 to 3,500 pCi/L. The highest concentrations of uranium, thorium, and radon gas and the highest radon-hazard-potential are in the well-drained permeable soils in the lower flood- plain deposits that underlie the city of Beaver

Auditing hazardous waste incineration

International Nuclear Information System (INIS)

Jayanty, R.K.M.; Allen, J.M.; Sokol, C.K.; von Lehmden, D.J.

1990-01-01

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

Shale gas, a hazardous exploitation

International Nuclear Information System (INIS)

Maincent, G.

2011-01-01

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.)

Study on the correlation between volatile fatty acids and gas production in dry fermentation of kitchen waste

Science.gov (United States)

Li, Qiangqiang; Ma, Yunfeng; Du, Boying; Wang, Qi; Hu, Qiongqiong; Bian, Yushan

2018-02-01

In this study, continuous kitchen waste fermentation and anaerobic digestion experiments were conducted to analyze the gas production potential, and to study the correlation between gas production rate and volatile fatty acid (VFAs) and its component concentration. During the experiment, the total solid(TS) concentration of the reaction system was increased by adding the kitchen waste, analysis of kitchen waste dry fermentation process to start, run, imbalance and imbalance after recovery and the parameters in the process of realizing the change trend and influencing factors of dry fermentation process, pH and ammonia concentration.

77 FR 2126 - Pipeline Safety: Implementation of the National Registry of Pipeline and Liquefied Natural Gas...

Science.gov (United States)

2012-01-13

... Natural Gas Operators AGENCY: Pipeline and Hazardous Materials Safety Administration (PHMSA), DOT. ACTION... DEPARTMENT OF TRANSPORTATION Pipeline and Hazardous Materials Safety Administration [Docket No...: ``Pipeline Safety: Updates to Pipeline and Liquefied Natural Gas Reporting Requirements.'' The final rule...

Gas release-based prescreening combined with reversed-phase HPLC quantitation for efficient selection of high-γ-aminobutyric acid (GABA)-producing lactic acid bacteria.

Science.gov (United States)

Wu, Qinglong; Shah, Nagendra P

2015-02-01

High γ-aminobutyric acid (GABA)-producing lactobacilli are promising for the manufacture of GABA-rich foods and to synthesize GRAS (generally recognized as safe)-grade GABA. However, common chromatography-based screening is time-consuming and inefficient. In the present study, Korean kimchi was used as a model of lactic acid-based fermented foods, and a gas release-based prescreening of potential GABA producers was developed. The ability to produce GABA by potential GABA producers in de Man, Rogosa, and Sharpe medium supplemented with or without monosodium glutamate was further determined by HPLC. Based on the results, 9 isolates were regarded as high GABA producers, and were further genetically identified as Lactobacillus brevis based on the sequences of 16S rRNA gene. Gas release-based prescreening combined with reversed-phase HPLC confirmation was an efficient and cost-effective method to identify high-GABA-producing LAB, which could be good candidates for probiotics. The GABA that is naturally produced by these high-GABA-producing LAB could be used as a food additive. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Oxidative degradation of ion-exchange resins in acid medium. Vol. 3

International Nuclear Information System (INIS)

Eskander, S.B.; Ghattas, N.K.

1996-01-01

Volume reduction of spent ion-exchange resins used in nuclear facilities receive increasing importance due to the increase in storage cost, unstable physical and chemical properties and their relatively high specific activity (in some cases up to 1 Ci per liter). The present study is part of research program on the treatment and immobilization of radioactive spent ion-exchange resins simulate; hydrogen peroxide was used for the oxidative degradation of spent ion-exchange resins simulate in sulphuric acid medium. Five liters ring digester developed in Karlsruhe nuclear research center-(KFK)- in germany was the chosen option to perform the oxidation process. The work reported focused on the kinetics and mechanism of the oxidation process. Heating the organic resins in sulphuric acid results in its carbonization and partial oxidation of only 1.7% of the carbon added. Results show that the oxidation reaction is a relatively slow process of first order with K value in the order of 10 -4 min -1 , and the main oxidation product was carbon dioxide. The production of carbon oxide in the off gas stream increased sharply by the addition of hydrogen peroxide to the hot sulphuric acid-resin mixture. The results obtained show that more than 97% of the carbon added was oxidized to carbon dioxide and carbon monoxide. The rate constant value (K) of this reaction was calculated to be (1.69±0.13) x 10 -2 min -1 . The results of gas chromatographic analysis indicate that no significant amounts of hazardous organic materials were detected in the off-gas streams. 6 figs., 4 tabs

Device with Complex System for Heat Utilization and Reduction of Hazardous Air Emissions

Directory of Open Access Journals (Sweden)

O. V. Kascheeva

2012-01-01

Full Text Available Investigations concern heat utilization and reduction of hazardous emissions occurring in residential buildings and accompanying operation of a great number of industrial enterprises in particular heat and power objects, and firstly, heat-generating units of small power located in densely populated residential areas without centralized heat supply.The investigation target is to reduce cost of heat produced by independent system of building heat supply, reduction of air pollution  due to hazardous gas emissions and reduction of heat pollution of the environment as a result of building ventilation system operation, ventilation of their internal and external sewerage network and higher reliability of their operation.The target is achieved because the device with complex system for heat utilization and reduction of hazardous air emissions has additionally an assembly tank for mixing flue gases, ventilation emissions and atmospheric air, heat pump. Evaporation zone of the pump is a condensator of the gas mixture and its condensate zone contains a heat supply line for a heat consumer. The line is equipped with assembling  and distributing collectors, pipeline connecting the heat supply line with the system of direct and return delivery water from a boiler house, a separator for division of liquid and gaseous mixture phases, neutralizing devices for separate reduction of concentrations of hazardous and odorous substances being released in gaseous and liquid portions of the mixture, a pipeline for periodic supply of air with higher concentration of hazardous and odorous substances in the boiler furnace. The supplied air is obtained as a result of its passing through gas filters at their regeneration when their exchange capacity is exhausted.

Internal dosimetry of tritiated hydrogen gas

International Nuclear Information System (INIS)

Peterman, B.F.; Johnson, J.R.; Dunford, D.W.; McElroy, R.G.C.

1985-02-01

This document is a report on experiments to quantify the doses that may occur from the tritium gas that is converted 'in vivo' to tritiated water following the exposure to tritiated hydrogen gas contaminated air. This report also includes theoretical evaluation of the radiological hazards from the uptake through skin of tritium from tritiated hydrogen adsorbed on surfaces

77 FR 16471 - Pipeline Safety: Implementation of the National Registry of Pipeline and Liquefied Natural Gas...

Science.gov (United States)

2012-03-21

... Registry of Pipeline and Liquefied Natural Gas Operators AGENCY: Pipeline and Hazardous Materials Safety... DEPARTMENT OF TRANSPORTATION Pipeline and Hazardous Materials Safety Administration 49 CFR Parts... Register (75 FR 72878) titled: ``Pipeline Safety: Updates to Pipeline and Liquefied Natural Gas Reporting...

Evaluation of Gas Retention in Waste Simulants: Intermediate-Scale Column and Open-Channel-Depth Tests

Energy Technology Data Exchange (ETDEWEB)

Powell, Michael R.; Gauglitz, Phillip A.; Denslow, Kayte M.; Fischer, Christopher M.; Heldebrant, David J.; Prowant, Matthew S.; Sande, Susan; Davis, James M.; Telander, Monty R.

2014-02-14

Gas generation in Hanford’s radioactive waste storage tanks can lead to gas accumulation within the layer of settled solids (sludge) at the tank bottom. The gas, which may be hazardous and/or flammable, is formed principally by radiation-driven chemical reactions. Accumulation of these gases within the sludge increases the sludge-layer volume, which decreases the available tank volume for waste storage. Further, accumulation of large amounts of gas in the sludge can potentially result in a relatively rapid release of the accumulated gas if the sludge-layer density is reduced to less than that of the overlying sludge or that of the supernatant liquid. The potential for rapid release of large amounts of hazardous and/or flammable gases is a safety hazard that needs to be managed. Accordingly, a thorough understanding is needed of the circumstances that can lead to problematic gas accumulation in sludge layers. The Deep-Sludge Gas Release Event Project (DSGREP) is tasked with developing an improved understanding of these gas release events.

Treatment of Some Hazardous Industrial Pollutants by Simple Oxidation Techniques

International Nuclear Information System (INIS)

Abd El-Rahman, N.M.

1999-01-01

Central treatment of Industrial wastewater requires pretreatment of some specific pollutants which may be not effectively degraded in down stream processes in central treatment unit. Some of the hazardous pollutants in industrial wastewater including acrylonitrile, pesticides and some commonly used dyes (active and acid dyes) have been subjected individually to oxidation using hydrogen peroxide catalyzed by ferrous ions in acidic solution. Treatment efficiency was monitored by chemical oxygen demand (COD) removal using a specially developed concentration/COD curves. Initial concentrations (in terms of COD) were 910 PPM, 1348 and 530 ppm and the respective COD reductions were 91, 98 and 99%, for the pesticide, acrylonitrile and the reactive dye. Oxidative degradation of polared and acid green also reduced COD by 99 and 100% respectively. The obtained results confirm the appropriateness of oxidative degradation as a pretreatment for some hazardous pollutants prior to treatment in central facilities or municipal activated sludge stations

Chemical Reaction between Boric Acid and Phosphine Indicates Boric Acid as an Antidote for Aluminium Phosphide Poisoning

Directory of Open Access Journals (Sweden)

Motahareh Soltani

2016-08-01

Full Text Available Objectives: Aluminium phosphide (AlP is a fumigant pesticide which protects stored grains from insects and rodents. When it comes into contact with moisture, AlP releases phosphine (PH3, a highly toxic gas. No efficient antidote has been found for AlP poisoning so far and most people who are poisoned do not survive. Boric acid is a Lewis acid with an empty p orbital which accepts electrons. This study aimed to investigate the neutralisation of PH3 gas with boric acid. Methods: This study was carried out at the Baharlou Hospital, Tehran University of Medical Sciences, Tehran, Iran, between December 2013 and February 2014. The volume of released gas, rate of gas evolution and changes in pH were measured during reactions of AlP tablets with water, acidified water, saturated boric acid solution, acidified saturated boric acid solution, activated charcoal and acidified activated charcoal. Infrared spectroscopy was used to study the resulting probable adduct between PH3 and boric acid. Results: Activated charcoal significantly reduced the volume of released gas (P <0.01. Although boric acid did not significantly reduce the volume of released gas, it significantly reduced the rate of gas evolution (P <0.01. A gaseous adduct was formed in the reaction between pure AlP and boric acid. Conclusion: These findings indicate that boric acid may be an efficient and non-toxic antidote for PH3 poisoning.

Intercomparison of the measurements of oxalic acid in aerosols by gas chromatography and ion chromatography

Science.gov (United States)

Kawamura, Kimitaka; Barrie, Leonard A.; Toom-Sauntry, Desiree

2010-12-01

Oxalate, the anion of oxalic acid, is one of the most abundant measurable organic species in atmospheric aerosols. Traditionally, this bifunctional species has been measured by gas chromatography (GC) after derivatization to butyl ester and by ion chromatography (IC) without derivatization. However, there are few published comparisons of the two techniques. Here, we report the results of an intercomparison study for the measurement of oxalic acid in Arctic aerosols (oxalic acid by GC ranged from 6.5-59.1 ng m -3 (av. 26.0 ng m -3, median 26.2 ng m -3) whereas those by IC ranged from 6.6-52.1 ng m -3 (av. 26.6 ng m -3, median 25.4 ng m -3). They showed a good correlation ( r = 0.84) with a slope of 0.96. Thus, observations of oxalate obtained by GC employing dibutyl esters are almost equal to those by IC. Because the accuracy of oxalic acid by GC method largely depends on the method used, it is important to strictly examine the recovery in each study.

Studies on Synthesis of Electrochemically Exfoliated Functionalized Graphene and Polylactic Acid/Ferric Phytate Functionalized Graphene Nanocomposites as New Fire Hazard Suppression Materials.

Science.gov (United States)

Feng, Xiaming; Wang, Xin; Cai, Wei; Qiu, Shuilai; Hu, Yuan; Liew, Kim Meow

2016-09-28

Practical application of functionalized graphene in polymeric nanocomposites is hampered by the lack of cost-effective and eco-friendly methods for its production. Here, we reported a facile and green electrochemical approach for preparing ferric phytate functionalized graphene (f-GNS) by simultaneously utilizing biobased phytic acid as electrolyte and modifier for the first time. Due to the presence of phytic acid, electrochemical exfoliation leads to low oxidized graphene sheets (a C/O ratio of 14.8) that are tens of micrometers large. Successful functionalization of graphene was confirmed by the appearance of phosphorus and iron peaks in the X-ray photoelectron spectrum. Further, high-performance polylactic acid/f-GNS nanocomposites are readily fabricated by a convenient masterbatch strategy. Notably, inclusion of well-dispersed f-GNS resulted in dramatic suppression on fire hazards of polylactic acid in terms of reduced peak heat-release rate (decreased by 40%), low CO yield, and formation of a high graphitized protective char layer. Moreover, obviously improvements in crystallization rate and thermal conductivities of polylactic acid nanocomposites were observed, highlighting its promising potential in practical application. This novel strategy toward the simultaneous exfoliation and functionalization for graphene demonstrates a simple yet very effective approach for fabricating graphene-based flame retardants.

Metals partitioning resulting from rotary kiln incineration of hazardous waste

International Nuclear Information System (INIS)

Richards, M.K.; Fournier, D.J. Jr.

1992-01-01

In response to the need for date on the partitioning of trace metals from hazardous waste incinerators, an extensive series of test was conducted in the summer of 1991 at the USEPA Incineration Research Facility (IRF) in Jefferson, Arkansas. These tests were conducted in the IRF's rotary kiln incinerator system (RKS) equipped with a pilot-scale Calvert Flux-Force/Condensation scrubber as the primary air pollution control system (APCS). The purpose of this test series was to extend the data base on trace metal partitioning and to investigate the effects of variations in incinerator operation on metal partitioning. Another objective was to evaluate the effectiveness of the scrubber for collecting flue gas metals. This series is a continuation of an ongoing IRF research program investigating trace metal partitioning and APCS collection efficiencies. Two previous test series were conducted using the RKS equipped with a venturi/packed-column scrubber and a single-state ionizing wet scrubber. The primary objective of this test series was to determine the fate of six hazardous and four nonhazardous trace metals fed to the RKS in a synthetic, organic-contaminated solid waste matrix. The six hazardous trace metals used were arsenic, barium, cadmium, chromium, mercury, and lead. The four nonhazardous trace metals--bismuth, copper, magnesium, and strontium--were included primarily to supply data to evaluate their potential for use as surrogates. The temperature, waste feed chlorine content, and scrubber pressure drop. The test program objectives were to identify. The partitioning of metals among kiln ash, scrubber liquor, and flue gas. Changes in metal partitioning related to variations in kiln exit gas temperature and waste feed chlorine content. The efficiency of the Calvert scrubber for collecting flue gas metals. The effects of scrubber pressure drop on metal collection efficiencies. 2 figs., 2 tabs

Concurrent Lactic and Volatile Fatty Acid Analysis of Microbial Fermentation Samples by Gas Chromatography with Heat Pre-treatment.

Science.gov (United States)

Darwin; WipaCharles; Cord-Ruwisch, Ralf

2018-01-01

Organic acid analysis of fermentation samples can be readily achieved by gas chromatography (GC), which detects volatile organic acids. However, lactic acid, a key fermentation acid is non-volatile and can hence not be quantified by regular GC analysis. However the addition of periodic acid to organic acid samples has been shown to enable lactic acid analysis by GC, as periodic acid oxidizes lactic acid to the volatile acetaldehyde. Direct GC injection of lactic acid standards and periodic acid generated inconsistent and irreproducible peaks, possibly due to incomplete lactic acid oxidation to acetaldehyde. The described method is developed to improve lactic acid analysis by GC by using a heat treated derivatization pre-treatment, such that it becomes independent of the retention time and temperature selection of the GC injector. Samples containing lactic acid were amended by periodic acid and heated in a sealed test tube at 100°C for at least 45 min before injecting it to the GC. Reproducible and consistent peaks of acetaldehyde were obtained. Simultaneous determination of lactic acid, acetone, ethanol, butanol, volatile fatty acids could also be accomplished by applying this GC method, enabling precise and convenient organic acid analysis of biological samples such as anaerobic digestion and fermentation processes. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Innovative technologies for the treatment of hazardous and mixed wastes

International Nuclear Information System (INIS)

Eyman, L.D.; Anderson, T.D.

1988-01-01

The treatment, storage, and disposal of hazardous and mixed wastes incur significant costs for Department of Energy (DOE) installations. These wastes must be managed under strict environmental controls and regulations to prevent the possibility of migration of hazardous materials to the biosphere. Through the Hazardous Waste Remedial Actions Program, the DOE is seeking to develop innovative ways of improving current treatment technologies to eliminate the hazardous components of wastes, reduce waste management costs, and minimize the volume requiring disposal as hazardous or mixed waste. Sponsored projects progress from research and development to field demonstration. Among the innovative technologies under development are supercritical water oxidation of hazardous chemicals, microwave-assisted destruction of chlorinated hydrocarbons, paramagnetic separation of metals from waste, detoxification and reclamation of waste acid, nitrate destruction through calcination, treatment/disposal of reactive metals, and methodologies for encapsulation. Technologies at a demonstration phase include detoxification of mixed waste sludge, microbial degradation of polychlorinated biphenyls in soil, and the remediation process for a hydrocarbon spill. 14 refs

Beyond low-level activity: On a 'non-radioactive' gas mantle

International Nuclear Information System (INIS)

Poljanc, Karin; Steinhauser, Georg; Sterba, Johannes H.; Buchtela, Karl; Bichler, Max

2007-01-01

Gas mantles for camping gas lanterns sometimes contain thorium compounds. During the last years, the use of thorium-free gas mantles has become more and more popular due to the avoidance of a radioactive heavy metal. We investigated a gas mantle type that is declared to be 'non-radioactive' and that can be bought in Austria at the moment. Methods used were Instrumental Neutron Activation Analysis (INAA), γ-spectroscopy, and Liquid Scintillation Counting (LSC). We found massive thorium contents of up to 259 mg per gas mantle. Leaching experiments showed that only 0.4% of the Th but approximately 90% of the decay products of 232 Th can be leached under conditions simulating sucking and chewing with human saliva. In this paper, the investigation of these gas mantles including the consideration of the environmental hazard caused by disposed mantles and the health hazard for unsuspecting consumers is presented and legal consequences are discussed for this fraud

The gas fireplace: a new burn hazard in the home.

Science.gov (United States)

Becker, L; Cartotto, R

1999-01-01

Gas fireplaces have become popular in recent years. This article presents the first reported case of a burn injury from contact with the glass front of a gas fireplace. An investigation of the surface temperature of the glass fronts of gas fireplaces was undertaken to clarify the risks posed by these units. Surface temperature measurements of the glass fronts of 3 common gas fireplace models were obtained using a thermocouple probe. Glass temperatures reached 200 degrees C within 6.5 minutes of ignition, climbing to 245 degrees C at 14 minutes after ignition. Glass temperature continued to rise beyond this point, but it could not be monitored because the adhesives securing the thermocouple probe melted. Glass temperatures of 50 degrees C were recorded at 30 minutes after the unit was shut off. The temperatures of the glass fronts of glass fireplaces are sufficient to cause cutaneous burns within seconds of contact both while the fireplace is in use and up to one half hour after it has been turned off. Current industry safety standards are not directed at the prevention of contact burns. We recommend that (1) mechanical guards be installed to create a barrier in front of the glass; (2) strict warning labels be applied to the units and ignition switches; and (3) burn prevention information be distributed with the owner's manual for these products.

Toxic and hazardous waste disposal. Volume 1. Processes for stabilization/solidification

International Nuclear Information System (INIS)

Pojasek, R.B.

1979-01-01

Processes for the stabilization and/or solidification of toxic, hazardous, and radioactive wastes are reviewed. The types of wastes classified as hazardous are defined. The following processes for the solidification of hazardous wastes are described: lime-based techniques; thermoplastic techniques; organic polymer techniques; and encapsulation. The following processes for the solidification of high-level radioactive wastes are described: calcination; glassification; and ceramics. The solidification of low-level radioactive wastes with asphalt, cement, and polymeric materials is also discussed. Other topics covered include: the use of an extruder/evaporator to stabilize and solidify hazardous wastes; effect disposal of fine coal refuse and flue gas desulfurization slurries using Calcilox additive stabilization; the Terra-Tite Process; the Petrifix Process; the SFT Terra-Crete Process; Sealosafe Process; Chemfix Process; and options for disposal of sulfur oxide wastes

Synthesis of Fe Nanoparticles Functionalized with Oleic Acid Synthesized by Inert Gas Condensation

Directory of Open Access Journals (Sweden)

L. G. Silva

2014-01-01

Full Text Available In this work, we study the synthesis of monodispersed Fe nanoparticles (Fe-NPs in situ functionalized with oleic acid. The nanoparticles were self-assembled by inert gas condensation (IGC technique by using magnetron-sputtering process. Structural characterization of Fe-NPs was performed by transmission electron microscopy (TEM. Particle size control was carried out through the following parameters: (i condensation zone length, (ii magnetron power, and (iii gas flow (Ar and He. Typically the nanoparticles generated by IGC showed diameters which ranged from ~0.7 to 20 nm. Mass spectroscopy of Fe-NPs in the deposition system allowed the study of in situ nanoparticle formation, through a quadrupole mass filter (QMF that one can use together with a mass filter. When the deposition system works without quadrupole mass filter, the particle diameter distribution is around +/−20%. When the quadrupole is in line, then the distribution can be reduced to around +/−2%.

Hydrofluoric acid burn resulting from ignition of gas from a compressed air duster.

Science.gov (United States)

Foster, Kevin N; Jones, LouAnn; Caruso, Daniel M

2003-01-01

A young female suffered burns to her hand after the ignition of gas from a compressed air duster. After debridement and dressing, the patient continued to have pain out of proportion to injury that was refractory to intravenous morphine. The material safety data sheet revealed that the chemical used was 1,1-difluoroethane. High temperatures can cause decompensation to form hydrofluoric acid. Calcium gluconate gel was applied topically to the patient's burns, which caused prompt and complete relief of her pain. A review of different compressed air duster products revealed that the main ingredient in each was a halogenated hydrocarbon. Although not considered flammable, all products have warnings regarding the possibility of ignition under various circumstances. Ignition of the gas in compressed air cleaners not only can cause flame burns, it can also cause chemical damage from exposure to hydrogen and fluoride ions. Prompt recognition and treatment is necessary to prevent severe injury.

76 FR 53086 - Pipeline Safety: Safety of Gas Transmission Pipelines

Science.gov (United States)

2011-08-25

... DEPARTMENT OF TRANSPORTATION Pipeline and Hazardous Materials Safety Administration 49 CFR Part 192 [Docket No. PHMSA-2011-0023] RIN 2137-AE72 Pipeline Safety: Safety of Gas Transmission Pipelines AGENCY: Pipeline and Hazardous Materials Safety Administration (PHMSA), Department of Transportation (DOT...

Flammable Gas Safety Self-Study 52827

Energy Technology Data Exchange (ETDEWEB)

Glass, George [Los Alamos National Laboratory

2016-03-17

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

Natural hazards in Goma and the surrounding villages, East African Rift System

Science.gov (United States)

Balagizi, Charles M.; Kies, Antoine; Kasereka, Marcellin M.; Tedesco, Dario; Yalire, Mathieu M.; McCausland, Wendy A.

2018-01-01

The city of Goma and its surrounding villages (Democratic Republic of the Congo, DRC) are among the world’s most densely populated regions strongly affected by volcanic hazards. In 2002, Nyiragongo volcano erupted destroying 10–15% of Goma and forced a mass evacuation of the population. Hence, the ~ 1.5 million inhabitants of Goma and Gisenyi (Rwanda) continue to live with the threat of new lava flows and other eruptive hazards from this volcano. The current network of fractures extends from Nyiragongo summit to Goma and continues beneath Lake Kivu, which gives rise to the fear that an eruption could even produce an active vent within the center of Goma or within the lake. A sub-lacustrine volcanic eruption with vents in the floor of the main basin and/or Kabuno Bay of Lake Kivu could potentially release about 300 km3 of carbon dioxide (CO2) and 60 km3 of methane (CH4) dissolved in its deep waters that would be catastrophic to populations (~ 2.5 million people) along the lake shores. For the time being, ongoing hazards related to Nyiragongo and Nyamulagira volcanoes silently kill people and animals, slowly destroy the environment, and seriously harm the health of the population. They include mazuku (CO2-rich locations where people often die of asphyxiation), the highly fluoridated surface and ground waters, and other locally neglected hazards. The volcanic gas plume causes poor air quality and acid rain, which is commonly used for drinking water. Given the large number of people at risk and the continued movement of people to Goma and the surrounding villages, there is an urgent need for a thorough natural hazards assessment in the region. This paper presents a general view of natural hazards in the region around Goma based on field investigations, CO2 measurements in mazuku, and chemistry data for Lake Kivu, rivers and rainwater. The field investigations and the datasets are used in conjunction with extremely rich-historical (1897–2000) and

Rapid and simple clean-up and derivatizaton procedure for the gas chromatographic determination of acidic drugs in plasma

NARCIS (Netherlands)

Roseboom, H.; Hulshoff, A.

1979-01-01

A rapid and simple clean-up and derivatization procedure that can be generally applied to the gas chromatographie (GC) determination of acidic drugs of various chemical and therapeutic classes is described. The drugs are extracted from acidified plasma with chloroform containing 5% of isopropanol,

Feasibility of flare gas reformation to practical energy in Farashband gas refinery: no gas flaring.

Science.gov (United States)

Rahimpour, Mohammad Reaza; Jokar, Seyyed Mohammad

2012-03-30

A suggested method for controlling the level of hazardous materials in the atmosphere is prevention of combustion in flare. In this work, three methods are proposed to recover flare gas instead of conventional gas-burning in flare at the Farashband gas refinery. These methods aim to minimize environmental and economical disadvantages of burning flare gas. The proposed methods are: (1) gas to liquid (GTL) production, (2) electricity generation with a gas turbine and, (3) compression and injection into the refinery pipelines. To find the most suitable method, the refinery units that send gas to the flare as well as the required equipment for the three aforementioned methods are simulated. These simulations determine the amount of flare gas, the number of GTL barrels, the power generated by the gas turbine and the required compression horsepower. The results of simulation show that 563 barrels/day of valuable GTL products is produced by the first method. The second method provides 25 MW electricity and the third method provides a compressed natural gas with 129 bar pressure for injection to the refinery pipelines. In addition, the economics of flare gas recovery methods are studied and compared. The results show that for the 4.176MMSCFD of gas flared from the Farashband gas refinery, the electricity production gives the highest rate of return (ROR), the lowest payback period, the highest annual profit and mild capital investment. Therefore, the electricity production is the superior method economically. Copyright © 2012 Elsevier B.V. All rights reserved.

46 CFR 153.900 - Certificates and authorization to carry a bulk liquid hazardous material.

Science.gov (United States)

2010-10-01

... ship must have a Subchapter D or I Certificate of Inspection that is endorsed to allow the cargo tank... requirements for the bulk liquid cargo; and (2) The ship— (i) Has a Certificate of Inspection, Certificate of...) CERTAIN BULK DANGEROUS CARGOES SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS...

Electrophilic acid gas-reactive fluid, proppant, and process for enhanced fracturing and recovery of energy producing materials

Science.gov (United States)

Fernandez, Carlos A.; Heldebrant, David J.; Bonneville, Alain; Jung, Hun Bok; Carroll, Kenneth C.

2018-01-23

An electrophilic acid gas-reactive fracturing fluid, proppant, and process are detailed. The fluid expands in volume to provide rapid and controlled increases in pressure that enhances fracturing in subterranean bedrock for recovery of energy-producing materials. The proppant stabilizes fracture openings in the bedrock to enhance recovery of energy-producing materials.

Acid dispersion abatement: the use of flue gas desulphurisation in the UK

Energy Technology Data Exchange (ETDEWEB)

Longhurst, J.W.S.; Health, B.A.; Gibber, D.C. [Manchester Metropolitan University, Manchester (United Kingdom). Atmospheric Research and Information Centre, Dept. of Environmental and Geographical Sciences

1995-12-31

This paper reviews and evaluates the development of the UK flue gas desulphurisation (FGD) programme. This programme on establishment in 1986 represented a planned and coherent approach to acid deposition abatement which would progressively reduce emissions whilst maintaining the UK`s coal fired power generation capacity. It was anticipated that at least 12000 MW of electricity generating plant would be retrofitted with FGD. The programme has effectively been abandoned in favour of market based approach to emission control which sets the targets to be achieved but not the means. As a consequence the retrofitted capacity in 1995 is just 6000 MW. 17 refs., 1 tab.

Modern tornado design of nuclear and other potentially hazardous facilities

International Nuclear Information System (INIS)

Stevenson, J.D.; Zhao, Y.

1996-01-01

Tornado wind loads and other tornado phenomena, including tornado missiles and differential pressure effects, have not usually been considered in the design of conventional industrial, commercial, or residential facilities in the United States; however, tornado resistance has often become a design requirement for certain hazardous facilities, such as large nuclear power plants and nuclear materials and waste storage facilities, as well as large liquefied natural gas storage facilities. This article provides a review of current procedures for the design of hazardous industrial facilities to resist tornado effects. 23 refs., 19 figs., 13 tabs

In situ rheology and gas volume in Hanford double-shell waste tanks

International Nuclear Information System (INIS)

Stewart, C.W.; Alzheimer, J.M.; Brewster, M.E.; Chen, G.; Reid, H.C.; Shepard, C.L.; Terrones, G.; Mendoza, R.E.

1996-09-01

This report is a detailed characterization of gas retention and release in 6 Hanford DS waste tanks. The results came from the ball rheometer and void fraction instrument in (flammable gas watch list) tanks SY-101, SY-103, AW-101, AN-103, AN-104, and AN-105 are presented. Instrument operation and derivation of data reduction methods are presented. Gas retention and release information is summarized for each tank and includes tank fill history and instrumentation, waste configuration, gas release, void fraction distribution, gas volumes, rheology, and photographs of the waste column from extruded core samples. Potential peak burn pressure is computed as a function of gas release fraction to portray the 'hazard signature' of each tank. It is shown that two tanks remain well below the maximum allowable pressure, even if the entire gas content were released and ignited, and that none of the others present a hazard with their present gas release behavior

76 FR 70953 - Pipeline Safety: Safety of Gas Transmission Pipelines

Science.gov (United States)

2011-11-16

... DEPARTMENT OF TRANSPORTATION Pipeline and Hazardous Materials Safety Administration 49 CFR Part 192 [Docket ID PHMSA-2011-0023] RIN 2137-AE72 Pipeline Safety: Safety of Gas Transmission Pipelines AGENCY: Pipeline and Hazardous Materials Safety Administration (PHMSA); DOT. ACTION: Advance notice of...

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

International Nuclear Information System (INIS)

Nuevas Paz, Lauro; Camayd Viera, Ivette

2014-01-01

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

Facile synthesis of improved room temperature gas sensing properties of TiO2 nanostructures: Effect of acid treatment

CSIR Research Space (South Africa)

Tshabalala, Zamaswazi P

2016-03-01

Full Text Available and Actuators B: Chemical Facile synthesis of improved room temperature gas sensing properties of TiO2 nanostructures: Effect of acid treatment Z.P. Tshabalalaa,b, D.E. Motaunga,∗, G.H. Mhlongoa,∗, O.M. Ntwaeaborwab,∗ a DST/CSIR, National Centre...

[Determination of residual solvents in 7-amino-3-chloro cephalosporanic acid by gas chromatography].

Science.gov (United States)

Ma, Li; Yao, Tong-wei

2011-01-01

To develop a gas chromatography method for determination of residual solvents in 7-amino-3-chloro cephalosporanic acid (7-ACCA). The residual levels of acetone, methanol, dichloromethane, ethyl acetate, isobutanol, pyridine and toluene in 7-ACCA were measured by gas chromatography using Agilent INNOWAX capillary column (30 m × 0.32 mm,0.5 μm). The initial column temperature was 70° maintained for 6 min and then raised (10°C/min) to 160°C for 1 min. Nitrogen gas was used as carrier and FID as detector. The flow of carrier was 1.0 ml/min, the temperature of injection port and detector was 200°C and 250°C, respectively. The limits of detection for acetone, methanol, dichloromethane, ethyl acetate, isobutanol, pyridine, toluene in 7-ACCA were 2.5 μg/ml, 1.5 μg/ml, 15 μg/ml, 2.5 μg/ml, 2.5 μg/ml, 2.5 μg/ml and 11 μg/ml, respectively. Only acetone was detected in the sample, and was less than the limits of Ch.P. The method can effectively detect the residual solvents in 7-ACCA.

Methodology for flammable gas evaluations

Energy Technology Data Exchange (ETDEWEB)

Hopkins, J.D., Westinghouse Hanford

1996-06-12

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

Natural gas encasement for highway crossings.

Science.gov (United States)

2015-03-01

The University Transportation Center for Alabama researchers examined the Alabama Department of : Transportations current policy regarding the encasement of natural gas and hazardous liquid pipelines at roadway : crossings. The group collected inf...

[Determination of fatty acids in natural cream and artificial cream by comprehensive two-dimensional gas chromatography-mass spectrometry].

Science.gov (United States)

Zhou, Ruize; Zhou, Ya; Mao, Ting; Jiang, Jie

2018-01-08

A method for the determination of 37 fatty acids in natural cream and artificial cream was developed by comprehensive two-dimensional gas chromatography-mass spectrometry (GC×GC-MS). The samples were extracted with toluene and acetyl chloride-methanol (1:9,v/v) solution was added to the extract for fat esterification. Finally, the fatty acids were analyzed by GC×GC-MS. The GC conditions were as follows:a DB-5 column (30 m×0.25 mm×0.25 μm) was set as the 1st dimensional column and a BPX-50 column (2.5 m×0.1 mm×0.25 μm) was the 2nd dimensional column. The primary oven temperature was programmed from 50℃ (held for 2 min) to 180℃ at a rate of 20℃/min, followed by an increase to 250℃ at 2.5℃/min, then raised up to 300℃ (held for 5 min) at 3℃/min. The ion source temperature was 200℃ with auxiliary temperature of 300℃ in scan mode. All fatty acids were separated effectively and determined accurately while the modulation period was 5s and the scan range of MS was m/z 40-385. This procedure was applied to analyze the fatty acids in commercial natural cream and artificial cream from Chinese markets, among which we found the characteristic components in different kinds of samples. Compared with gas chromatography-flame ionization detector (GC-FID), GC×GC-MS method was more sensitive and more components of fatty acids were detected. Conclusively, this work suggests a new technical approach in analyzing fatty acids in natural cream and artificial cream, which is meaningful to ensure the quality identification and safety of natural cream.

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

Directory of Open Access Journals (Sweden)

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.

78 FR 16045 - Safety Advisory: Unauthorized Marking of Compressed Gas Cylinders

Science.gov (United States)

2013-03-13

... DEPARTMENT OF TRANSPORTATION Pipeline and Hazardous Materials Safety Administration [Docket No. PHMSA-2013-0019; Notice No. 13-03] Safety Advisory: Unauthorized Marking of Compressed Gas Cylinders AGENCY: Pipeline and Hazardous Materials Safety Administration (PHMSA), DOT. ACTION: Safety Advisory...

A new method for infrared imaging of air currents in and around critical hazard fume hoods

International Nuclear Information System (INIS)

Mulac, W.A.; McCreary, J.R.; Schmalz, H.

1992-01-01

A real time method of measuring and recording the efficacy of vapor containment in and around critical hazard fume hoods is being developed. An infrared camera whose response is restricted to a spectral range that overlaps a strong absorption band in a non-toxic gas is used to render real-time video images of the presence and flow of the gas. The gas, nitrous oxide, is ejected in a continuous stream in and around fume hoods that are to be certified capable of containing hazardous fumes. The principle advantage is that various scenarios of air flow displacement in and outside the hood can be easily investigated; the principle limitation is the necessity of high tracer gas concentration to obtain strong visualizations. We hope that this technique can be found to be an effective and safe method to test hoods in locations that were built before present regulations were promulgated

75 FR 1235 - Revisions to the Requirements for: Transboundary Shipments of Hazardous Wastes Between OECD...

Science.gov (United States)

2010-01-08

..., Greece, Hungary, Iceland, Ireland, Italy, Japan, Luxembourg, Mexico, the Netherlands, New Zealand, Norway... Requirements for: Transboundary Shipments of Hazardous Wastes Between OECD Member Countries, Export Shipments of Spent Lead- Acid Batteries, Submitting Exception Reports for Export Shipments of Hazardous Wastes...

LISREL Model Medical Solid Infectious Waste Hazardous Hospital Management In Medan City

Science.gov (United States)

Simarmata, Verawaty; Siahaan, Ungkap; Pandia, Setiaty; Mawengkang, Herman

2018-01-01

Hazardous and toxic waste resulting from activities at most hospitals contain various elements of medical solid waste ranging from heavy metals that have the nature of accumulative toxic which are harmful to human health. Medical waste in the form of gas, liquid or solid generally include the category or the nature of the hazard and toxicity waste. The operational in activities of the hospital aims to improve the health and well-being, but it also produces waste as an environmental pollutant waters, soil and gas. From the description of the background of the above in mind that the management of solid waste pollution control medical hospital, is one of the fundamental problems in the city of Medan and application supervision is the main business licensing and control alternatives in accordance with applicable regulations.

A study on hazard types occurring in hydrogen facilities

International Nuclear Information System (INIS)

Cho, Nam Chul; Jae, Moo Sung; Eon, Yang Joon

2004-01-01

Hydrogen has ideal characteristics as an energy carrier. Hydrogen can be used as a clean fuel in a variety of energy end-use sectors including the conversion to electricity. After combustion, it produces only water. Therefore, the concept of hydrogen energy system has attracted much interest worldwide. But hydrogen has a defect that the explosion risk is high to an inflammable gas of a colorless, tasteless and odorless. Therefore, to use the hydrogen to the source of energy, hydrogen accident sequences and causes analysis must be needed. For this, hazard types occurring in hydrogen facilities have been considered through the case of domestic and foreign hydrogen accident in this study and hazard types to be considered are ignition, leaks, hydrogen dispersion, fire an explosion, storage vessel failure, vent and exhaust system, purging, condensation of air, hydrogen embrittlement, physiological hazard, and collisions during transportation

A proposal for a test method for assessment of hazard property HP 12 (“Release of an acute toxic gas”) in hazardous waste classification - Experience from 49 waste

OpenAIRE

Hennebert , Pierre; Samaali , Ismahen; Molina , Pauline

2016-01-01

International audience; A stepwise method for assessment of the HP 12 is proposed and tested with 49 waste samples. The hazard property HP 12 is defined as “Release of an acute toxic gas”: waste which releases acute toxic gases (Acute Tox. 1, 2 or 3) in contact with water or an acid. When a waste contains a substance assigned to one of the following supplemental hazards EUH029, EUH031 and EUH032, it shall be classified as hazardous by HP 12 according to test methods or guidelines (EC, 2014a, ...

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

Science.gov (United States)

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…

Measuring Gas-Phase Basicities of Amino Acids Using an Ion Trap Mass Spectrometer: A Physical Chemistry Laboratory Experiment

Science.gov (United States)

Sunderlin, Lee S.; Ryzhov, Victor; Keller, Lanea M. M.; Gaillard, Elizabeth R.

2005-01-01

An experiment is performed to measure the relative gas-phase basicities of a series of five amino acids to compare the results to literature values. The experiments use the kinetic method for deriving ion thermochemistry and allow students to perform accurate measurements of thermodynamics in a relatively short time.

Mixed microalgae consortia growth under higher concentration of CO2 from unfiltered coal fired flue gas: Fatty acid profiling and biodiesel production.

Science.gov (United States)

Aslam, Ambreen; Thomas-Hall, Skye R; Manzoor, Maleeha; Jabeen, Faiza; Iqbal, Munawar; Uz Zaman, Qamar; Schenk, Peer M; Asif Tahir, M

2018-02-01

Biodiesel is produced by transesterification of fatty acid methyl esters (FAME) from oleaginous microalgae feedstock. Biodiesel fuel properties were studied and compared with biodiesel standards. Qualitative analysis of FAME was done while cultivating mixed microalgae consortia under three concentrations of coal fired flue gas (1%, 3.0% and 5.5% CO 2 ). Under 1% CO 2 concentration (flue gas), the FAME content was 280.3 μg/mL, whereas the lipid content was 14.03 μg/mL/D (day). Both FAMEs and lipid contents were low at other CO 2 concentrations (3.0 and 5.5%). However, mixed consortia in the presence of phosphate buffer and flue gas (PB + FG) showed higher saturated fatty acids (SFA) (36.28%) and unsaturated fatty acids (UFA) (63.72%) versus 5.5% CO 2 concentration, which might be responsible for oxidative stability of biodiesel. Subsequently, higher cetane number (52) and low iodine value (136.3 gI 2 /100 g) biodiesel produced from mixed consortia (PB + FG) under 5.5% CO 2 along with 50 mM phosphate buffer were found in accordance with European (EN 14214) standard. Results revealed that phosphate buffer significantly enhanced the biodiesel quality, but reduced the FAME yield. This study intended to develop an integrated approach for significant improvement in biodiesel quality under surplus phosphorus by utilizing waste flue gas (as CO 2 source) using microalgae. The CO 2 sequestration from industrial flue gas not only reduced greenhouse gases, but may also ensure the sustainable and eco-benign production of biodiesel. Copyright © 2018. Published by Elsevier B.V.

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

Energy Technology Data Exchange (ETDEWEB)

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.

Evaluation and control of radon daughter hazards in uranium mines

International Nuclear Information System (INIS)

Holaday, D.A.

1974-11-01

This monograph discusses primarily those health hazards to uranium miners which are produced by exposure to ionizing radiation. Emphasis is placed on the areas of evaluation of exposures to the radioactive gas radon-222 and its short-lived transformation products, and methods of controlling such exposures. A limited discussion of the biological effects of radon and radon daughters is undertaken, and some procedures are given for evaluating hazards created by other common contaminants of mine atmospheres. A large amount of information exists on these topics, some of which is unpublished or is not readily available. While efforts were made to obtain data from all sources, undoubtedly some valuable work was overlooked. The monograph is an endeavor to assemble pertinent information and make it available to those who are concerned with producing uranium at minimal risks. Where they were available, a variety of procedures for evaluating hazards are given, and examples of systems for controlling hazards are included. 154 references

A five-year history of hazardous materials incidents in Chester County, PA

International Nuclear Information System (INIS)

Shorten, C.V.; McNamara, J.

1993-01-01

The Emergency Planning and Community Right-to-Know Act (EPCRA) of 1986 established Local Emergency Planning Committees (LEPCs) to oversee emergency response planning at the community level. In Pennsylvania, each county was assigned its own LEPC, and Chester County held its first LEPC meeting on October 15, 1987. From the data of that meeting through September 1992, 300 hazardous materials incidents have been reported. The majority of these incidents were met with fire department response, but several warranted response by hazardous materials teams. This report presents an analysis of the database of reported hazardous materials incidents in Chester County, including chemical identification, amount released, type of response, location, and trends. Over 235 of the reported spills were either gasoline, diesel fuel, home heating oil, or kerosene, often in five to 50 gallon amounts from transportation accidents. A number of extremely hazardous substance (EHS) incidents were reported, however, including sulfuric acid, chlorine, ammonia, phosphorus, formaldehyde, bromine, methyl mercaptan, and hydrofluoric acid. The most commonly released EHS's were ammonia and chlorine. The number of hazardous materials incidents reported in Chester County increased from only 14 in 1988 to 95 in 1991, with 67 in 1992 through September. This dramatic increase is attributable to both increased reporting and an increased number of incidents. This database clearly indicates both the success of EPCRA reporting system and the magnitude of hazardous materials incidents in this part of Pennsylvania

Hazards analyses of hydrogen evolution and ammonium nitrate accumulation in DWPF -- Revision 1

International Nuclear Information System (INIS)

Holtzscheiter, E.W.

1994-01-01

This revision consists of two reports, the first of which is an analysis of potential ammonium nitrate explosion hazards in the DWPF (Defense Waste Processing Facility). Sections describe the effect of impurities (organic and inorganic (chlorides, chromates, metals and oxides)); the consequences of a hydrogen deflagration or detonation; the role of confinement; the action of heat on ammonium nitrate; the thermal decomposition of ammonium nitrate; the hazard of spontaneous heating; and the explosive decomposition of ammonium nitrate. The second report, Hazard analysis of hydrogen evolution in DWPF: Process vessels and vent system for the late wash/nitric acid flowsheet, contains a description of a revised model for hydrogen generation based on the late wash/nitric acid process. The second part of the report is a sensitivity analysis of the base case conditions and the hydrogen generation model

New lidar challenges for gas hazard management in industrial environments

Science.gov (United States)

Cézard, Nicolas; Liméry, Anasthase; Bertrand, Johan; Le Méhauté, Simon; Benoit, Philippe; Fleury, Didier; Goular, Didier; Planchat, Christophe; Valla, Matthieu; Augère, Béatrice; Dolfi-Bouteyre, Agnès.

2017-10-01

The capability of Lidars to perform range-resolved gas profiles makes them an appealing choice for many applications. In order to address new remote sensing challenges, arising from industrial contexts, Onera currently develops two lidar systems, one Raman and one DIAL. On the Raman side, a high spatial-resolution multi-channel Raman Lidar is developed in partnership with the French National Radioactive Waste Management Agency (Andra). This development aims at enabling future monitoring of hydrogen gas and water vapor profiles inside disposal cells containing radioactive wastes. We report on the development and first tests of a three-channel Raman Lidar (H2, H2O, N2) designed to address this issue. Simultaneous hydrogen and water vapor profiles have been successfully performed along a 5m-long gas cell with 1m resolution at a distance of 85 m. On the DIAL side, a new instrumental concept is being explored and developed in partnership with Total E and P. The objective is to perform methane plume monitoring and flux assessment in the vicinity of industrials plants or platforms. For flux assessment, both gas concentration and air speed must be profiled by lidar. Therefore, we started developing a bi-function, all-fiber, coherent DIAL/Doppler Lidar. The first challenge was to design and build an appropriate fiber laser source. The achieved demonstrator delivers 200 W peak power, polarized, spectrally narrow (<15 MHz), 110 ns pulses of light out of a monomode fiber at 1645 nm. It fulfills the requirements for a future implementation in a bi-function Dial/Doppler lidar with km-range expectation. We report on the laser and lidar architecture, and on first lidar tests at 1645 nm.

DEMONSTRATION BULLETIN: GAS-PHASE CHEMICAL REDUCTION - ECO LOGIC INTERNATIONAL, INC.

Science.gov (United States)

The patented Eco Logic Process employs a gas-phase reduction reaction of hydrogen with organic and chlorinated organic compounds at elevated temperatures to convert aqueous and oily hazardous contaminants into a hydrocarbon-rich gas product. After passing through a scrubber, the ...

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

International Nuclear Information System (INIS)

Hussain, I.; Ullah, R.

2013-01-01

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)

Clean recycle and utilization of hazardous iron-bearing waste in iron ore sintering process.

Science.gov (United States)

Gan, Min; Ji, Zhiyun; Fan, Xiaohui; Chen, Xuling; Zhou, Yang; Wang, Guojing; Tian, Ye; Jiang, Tao

2018-04-18

Applying recycled iron-bearing waste materials (RIM) into iron ore sintering process is the general disposal approach worldwide, while its use is still a thorny problem. Results showed that adding RIM increased contents of hazardous elements (K, Na, Pb, Zn, and Cl) in sinter product, and also enhanced emission concentration of PM 2.5 in flue gas; increasing reaction temperature, and contents of CaO & coke breeze in raw mixtures improved hazardous elements removal. Based on these features, a novel method through granulating natural iron ores and RIM separately and distributing granulated RIM in bottom sintering layers was proposed for clean RIM cycle. When recycling 5% RIM, granulating RIM separately with higher contents of CaO and coke breeze removed hazardous elements effectively, the contents of which in sinter were reduced to comparable level of the case without RIM. Moreover, distributing RIM in bottom sintering layer reached intensive release of hazardous elements and PM 2.5 during sintering, which reduced the flue gas volume needing purification by about 2/3. Through activated carbon purification, about 60% of PM 2.5 comprised high contents of hazardous elements was removed. Novel technique eliminated the negative impact of RIM and has the prospect to reach clean recycle in sinter-making plants. Copyright © 2018. Published by Elsevier B.V.

Decoupling damage mechanisms in acid-fractured gas/condensate reservoirs

Energy Technology Data Exchange (ETDEWEB)

Bachman, R.C.; Walters, D.A. [Taurus Reservoir Solutions Ltd., Calgary, AB (Canada); Settari, A. [Calgary Univ., AB (Canada); Rahim, Z.; Ahmed, M.S. [Saudi Aramco, Dhahran (Saudi Arabia)

2006-07-01

The Khuff is a gas condensate field located 11,500 feet beneath the producing Ghawar oil field in Saudi Arabia. Wells are mainly acid fracture stimulated following drilling with excellent fracture conductivity and length properties. The wells experience a quick production loss however, after tie-in which eventually stabilizes after two to five months. In order to identify the source of productivity loss, such as near well liquid dropout, fracture conductivity loss, reservoir permeability loss due to increased effective stress, a study of a well in the Khuff field was conducted. The study reviewed basic geomechanical and reservoir properties and identified the mechanisms of production loss. The paper presented the methodology, data and preliminary analysis, relative permeability and results of the history matching. It was concluded that traditional production type curves in cases with changing skin may indicate that transient flow is occurring when boundary effects are felt. In addition, stress dependent fracture conductivity and reservoir permeability can be modeled with simpler pressure dependent functions for relatively low overall loss in reservoir pressure. 30 refs., 25 figs., 1 appendix.

Landscape susceptibility, hazard and risk assessments along pipeline corridors in Canada

Energy Technology Data Exchange (ETDEWEB)

Blais-Stevens, A.; Couture, R.; Page, A. [Natural Resources Canada, Ottawa, ON (Canada). Geological Survey of Canada; Koch, J.; Clague, J.J. [Simon Fraser Univ., Burnaby, BC (Canada); Lipovsky, P.S. [Yukon Geological Survey, Whitehorse, YT (Canada)

2010-07-01

This article discussed work that was carried out to inventory landslides and assess hazards along two proposed gas-pipeline routes in the North. Landslide inventories and hazard assessments are necessary to quantify and qualify the risk of environmental impacts from landslides on linear infrastructure. The Yukon Alaska Highway Pipeline and the Mackenzie Gas Project Pipeline, which will both be over 800 kilometres in length, will cross harsh landscapes characterized by permafrost terrain and will be at risk from geological hazards, including landslides with debris flows, earthquakes, subsidence, and permafrost degradation. The work involved inventorying and mapping landslides via aerial photography and field visits to identify the frequency-magnitude relationships for debris flow fans along the route and the creation of qualitative parametric landslide maps for both proposed pipeline corridors. A good correlation was found between actual landslide distribution and the landslide susceptibility maps. For the Mackenzie Valley Pipeline Corridor, most landslides have occurred in fine unconsolidated sediments and shallow slopes. Landslides in the Yukon Alaska Highway Corridor mostly happened in unconsolidated sediments, but a few took place in bedrock with high relief. The preliminary investigation revealed that a slope hazard exists in both corridors and must be taken into account during pipeline development. The results are intended to facilitate better decision-making for planning, constructing, and maintaining safe and economically viable pipeline routes in Northern Canada. The mapping methodology was outlined. 13 refs., 1 tab., 6 figs.

CO- and HCl-free synthesis of acid chlorides from unsaturated hydrocarbons via shuttle catalysis

Science.gov (United States)

Fang, Xianjie; Cacherat, Bastien; Morandi, Bill

2017-11-01

The synthesis of carboxylic acid derivatives from unsaturated hydrocarbons is an important process for the preparation of polymers, pharmaceuticals, cosmetics and agrochemicals. Despite its industrial relevance, the traditional Reppe-type carbonylation reaction using pressurized CO is of limited applicability to laboratory-scale synthesis because of: (1) the safety hazards associated with the use of CO, (2) the need for special equipment to handle pressurized gas, (3) the low reactivity of several relevant nucleophiles and (4) the necessity to employ different, often tailor-made, catalytic systems for each nucleophile. Herein we demonstrate that a shuttle-catalysis approach enables a CO- and HCl-free transfer process between an inexpensive reagent, butyryl chloride, and a wide range of unsaturated substrates to access the corresponding acid chlorides in good yields. This new transformation provides access to a broad range of carbonyl-containing products through the in situ transformation of the reactive acid chloride intermediate. In a broader context, this work demonstrates that isodesmic shuttle-catalysis reactions can unlock elusive catalytic reactions.

Radiolytic gas generation in plutonium contaminated waste materials

International Nuclear Information System (INIS)

Kazanjian, A.R.

1976-01-01

Many plutonium contaminated waste materials decompose into gaseous products because of exposure to alpha radiation. The gases generated (usually hydrogen) over long-storage periods may create hazardous conditions. To determine the extent of such hazards, knowing the gas generation yields is necessary. These yields were measured by contacting some common Rocky Flats Plant waste materials with plutonium and monitoring the enclosed atmospheres for extensive periods of time. The materials were Plexiglas, polyvinyl chloride, glove-box gloves, machining oil, carbon tetrachloride, chlorothene VG solvent, Kimwipes (dry and wet), polyethylene, Dowex-1 resin, and surgeon's gloves. Both 239 Pu oxide and 238 Pu oxide were used as radiation sources. The gas analyses were made by mass spectrometry and the results obtained were the total gas generation, the hydrogen generation, the oxygen consumption rate, and the gas composition over the entire storage period. Hydrogen was the major gas produced in most of the materials. The total gas yields varied from 0.71 to 16 cm 3 (standard temperature pressure) per day per curie of plutonium. The oxygen consumption rates varied from 0.0088 to 0.070 millimoles per day per gram of plutonium oxide-239 and from 0.0014 to 0.0051 millimoles per day per milligram 238 Pu

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

DEFF Research Database (Denmark)

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...

Comparative alternative materials assessment to screen toxicity hazards in the life cycle of CIGS thin film photovoltaics

International Nuclear Information System (INIS)

Eisenberg, Daniel A.; Yu, Mengjing; Lam, Carl W.; Ogunseitan, Oladele A.; Schoenung, Julie M.

2013-01-01

Highlights: • Comparative alternatives assessment of thin film manufacturing technologies. • Development of chemical alternatives assessment in a life cycle context. • Screening of manufacturing and solar cell hazardous substances simultaneously. -- Abstract: Copper–indium–gallium–selenium–sulfide (CIGS) thin film photovoltaics are increasingly penetrating the market supply for consumer solar panels. Although CIGS is attractive for producing less greenhouse gas emissions than fossil-fuel based energy sources, CIGS manufacturing processes and solar cell devices use hazardous materials that should be carefully considered in evaluating and comparing net environmental benefits of energy products. Through this research, we present a case study on the toxicity hazards associated with alternative materials selection for CIGS manufacturing. We applied two numeric models, The Green Screen for Safer Chemicals™ and the Toxic Potential Indicator. To improve the sensitivity of the model outputs, we developed a novel, life cycle thinking based hazard assessment method that facilitates the projection of hazards throughout material life cycles. Our results show that the least hazardous CIGS solar cell device and manufacturing protocol consist of a titanium substrate, molybdenum metal back electrode, CuInS 2 p-type absorber deposited by spray pyrolysis, ZnS buffer deposited by spray ion layer gas reduction, ZnO:Ga transparent conducting oxide (TCO) deposited by sputtering, and the encapsulant polydimethylsiloxane

Water-molten uranium hazard analysis. Final report. LATA report No. 92

International Nuclear Information System (INIS)

Hughes, P.S.; Rigdon, L.D.; Donham, B.J.

1979-01-01

The hazard potential of cooling water leakage into the crucible of molten uranium in the MARS laser isotope separation experiment was investigated. A vapor-phase explosion is highly unlikely in any of the scenarios defined for MARS. For the operating basis accident, the gas pressure transient experienced by the vessel wall is 544 psia peak with a duration of 200 μs, and the peak hoop stress is about 20,000 psi in a 0.5-in. wall. Design and procedural recommendations are given for reducing the hazard

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

Directory of Open Access Journals (Sweden)

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.

Atmospheric dispersion prediction and source estimation of hazardous gas using artificial neural network, particle swarm optimization and expectation maximization

Science.gov (United States)

Qiu, Sihang; Chen, Bin; Wang, Rongxiao; Zhu, Zhengqiu; Wang, Yuan; Qiu, Xiaogang

2018-04-01

Hazardous gas leak accident has posed a potential threat to human beings. Predicting atmospheric dispersion and estimating its source become increasingly important in emergency management. Current dispersion prediction and source estimation models cannot satisfy the requirement of emergency management because they are not equipped with high efficiency and accuracy at the same time. In this paper, we develop a fast and accurate dispersion prediction and source estimation method based on artificial neural network (ANN), particle swarm optimization (PSO) and expectation maximization (EM). The novel method uses a large amount of pre-determined scenarios to train the ANN for dispersion prediction, so that the ANN can predict concentration distribution accurately and efficiently. PSO and EM are applied for estimating the source parameters, which can effectively accelerate the process of convergence. The method is verified by the Indianapolis field study with a SF6 release source. The results demonstrate the effectiveness of the method.

Mercury in the natural gas industry in Canada

International Nuclear Information System (INIS)

Wren, C.D.; Farrell, C.W.

1995-01-01

There are an estimated 1,500 natural gas facilities across Canada, most of which used mercury (Hg) in metering equipment at one time or another. Although the use of mercury has ceased, many gas industry buildings still contain detectable levels of Hg in air. Air Hg levels are generally low but indoor remediation is suggested. Worker exposure to the air Hg levels is not considered a significant hazard. Very high soil Hg levels have been observed at numerous sites. Soil Hg levels do not pose an immediate human hazard but are sufficient to be hazardous to ecological receptors. The area of soil contamination is generally within the buildings or within a few metres of the nearest door. Downward movement of the Hg does not generally extent more than one metre. Remediation of contaminated soil with on-site thermal desorption is recommended as the appropriate soil clean-up technology. 2 refs., 1 tab

delta 13C analyses of vegetable oil fatty acid components, determined by gas chromatography--combustion--isotope ratio mass spectrometry, after saponification or regiospecific hydrolysis.

Science.gov (United States)

Woodbury, S E; Evershed, R P; Rossell, J B

1998-05-01

The delta 13C values of the major fatty acids of several different commercially important vegetable oils were measured by gas chromatography--combustion--isotope ratio mass spectrometry. The delta 13C values obtained were found to fall into two distinct groups, representing the C3 and C4 plants classes from which the oils were derived. The delta 13C values of the oils were measured by continuous flow elemental isotope ratio mass spectrometry and were found to be similar to their fatty acids, with slight differences between individual fatty acids. Investigations were then made into the influence on the delta 13C values of fatty acids of the position occupied on the glycerol backbone. Pancreatic lipase was employed to selectively hydrolyse fatty acids from the 1- and 3-positions with the progress of the reaction being followed by high-temperature gas chromatography in order to determine the optimum incubation time. The 2-monoacylglycerols were then isolated by thin-layer chromatography and fatty acid methyl esters prepared. The delta 13C values obtained indicate that fatty acids from any position on the glycerol backbone are isotopically identical. Thus, whilst quantification of fatty acid composition at the 2-position and measurement of delta 13C values of oils and their major fatty acids are useful criteria in edible oil purity assessment, measurement of delta 13C values of fatty acids from the 2-position does not assist with oil purity assignments.

Interactions of hydrated divalent metal cations with nucleic acid bases. How to relate the gas phase data to solution situation and binding selectivity in nucleic acids

Czech Academy of Sciences Publication Activity Database

Šponer, Judit E.; Sychrovský, Vladimír; Hobza, Pavel; Šponer, Jiří

2004-01-01

Roč. 6, č. 10 (2004), s. 2772-2780 ISSN 1463-9076 R&D Projects: GA MŠk LN00A016; GA MŠk LN00A032 Grant - others:Wellcome Trust(GB) GR067507MF Institutional research plan: CEZ:AV0Z5004920 Keywords : nucleic acids * gas phase * guanine Subject RIV: BO - Biophysics Impact factor: 2.076, year: 2004

Comparative alternative materials assessment to screen toxicity hazards in the life cycle of CIGS thin film photovoltaics.

Science.gov (United States)

Eisenberg, Daniel A; Yu, Mengjing; Lam, Carl W; Ogunseitan, Oladele A; Schoenung, Julie M

2013-09-15

Copper-indium-gallium-selenium-sulfide (CIGS) thin film photovoltaics are increasingly penetrating the market supply for consumer solar panels. Although CIGS is attractive for producing less greenhouse gas emissions than fossil-fuel based energy sources, CIGS manufacturing processes and solar cell devices use hazardous materials that should be carefully considered in evaluating and comparing net environmental benefits of energy products. Through this research, we present a case study on the toxicity hazards associated with alternative materials selection for CIGS manufacturing. We applied two numeric models, The Green Screen for Safer Chemicals and the Toxic Potential Indicator. To improve the sensitivity of the model outputs, we developed a novel, life cycle thinking based hazard assessment method that facilitates the projection of hazards throughout material life cycles. Our results show that the least hazardous CIGS solar cell device and manufacturing protocol consist of a titanium substrate, molybdenum metal back electrode, CuInS₂ p-type absorber deposited by spray pyrolysis, ZnS buffer deposited by spray ion layer gas reduction, ZnO:Ga transparent conducting oxide (TCO) deposited by sputtering, and the encapsulant polydimethylsiloxane. Copyright © 2013 Elsevier B.V. All rights reserved.

Reclamation of acid, toxic coal spoils using wet flue gas desulfurization by-product, fly ash and sewage sludge. Final report

Energy Technology Data Exchange (ETDEWEB)

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.

Reclamation of acid, toxic coal spoils using wet flue gas desulfurization by-product, fly ash and sewage sludge. Final report

International Nuclear Information System (INIS)

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 4 ), calcium sulfite (CaSO 3 ), calcium carbonate (CaCO 3 ), calcium hydroxide [Ca(OH) 2 ], and fly ash. Some scrubbing processes produce almost pure gypsum (CaSO 4 2H 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

75 FR 36615 - Pipeline Safety: Information Collection Gas Distribution Annual Report Form

Science.gov (United States)

2010-06-28

... DEPARTMENT OF TRANSPORTATION Pipeline and Hazardous Materials Safety Administration 49 CFR Part 192 [Docket No. PHMSA-RSPA-2004-19854] Pipeline Safety: Information Collection Gas Distribution Annual Report Form AGENCY: Pipeline and Hazardous Materials Safety Administration (PHMSA), DOT. ACTION: Request...

A Discussion of SY-101 Crust Gas Retention and Release Mechanisms

International Nuclear Information System (INIS)

Mendoza, D.P.; Mahoney, L.A.; Gauglitz, P.A.; Rassat, S.D.; Caley, S.M.

1999-01-01

The flammable gas hazard in Hanford waste tanks was made an issue by the behavior of double-shell Tank (DST) 241-SY-101 (SY-101). Shortly after SY-101 was filled in 1980, the waste level began rising periodically, due to the generation and retention of gases within the slurry, and then suddenly dropping as the gases were released. An intensive study of the tank's behavior revealed that these episodic releases posed a safety hazard because the released gas was flammable, and, in some cases, the volume of gas released was sufficient to exceed the lower flammability limit (LFL) in the tank headspace (Alleinann et al. 1993). A mixer pump was installed in SY-101 in late 1993 to prevent gases from building up in the settled solids layer, and the large episodic gas releases have since ceased (Allemann et al. 1994; Stewart et al. 1994; Brewster et al. 1995). However, the surface level of SY-101 has been increasing since at least 1995, and in recent months the level growth has shown significant and unexpected acceleration. Based on a number of observations and measurements, including data from the void fraction instrument (VFI), we have concluded that the level growth is caused largely by increased gas retention in the floating crust. In September 1998, the crust contained between about 21 and 43% void based on VFI measurements (Stewart et al. 1998). Accordingly, it is important to understand the dominant mechanisms of gas retention, why the gas retention is increasing, and whether the accelerating level increase will continue, diminish or even reverse. It is expected that the retained gas in the crust is flammable, with hydrogen as a major constituent. This gas inventory would pose a flammable gas hazard if it were to release suddenly. In May 1997, the mechanisms of bubble retention and release from crust material were the subject of a workshop. The evaluation of the crust and potential hazards assumed a more typical void of roughly 15% gas. It could be similar to

A Discussion of SY-101 Crust Gas Retention and Release Mechanisms

Energy Technology Data Exchange (ETDEWEB)

SD Rassat; PA Gauglitz; SM Caley; LA Mahoney; DP Mendoza

1999-02-23

The flammable gas hazard in Hanford waste tanks was made an issue by the behavior of double-shell Tank (DST) 241-SY-101 (SY-101). Shortly after SY-101 was filled in 1980, the waste level began rising periodically, due to the generation and retention of gases within the slurry, and then suddenly dropping as the gases were released. An intensive study of the tank's behavior revealed that these episodic releases posed a safety hazard because the released gas was flammable, and, in some cases, the volume of gas released was sufficient to exceed the lower flammability limit (LFL) in the tank headspace (Allemann et al. 1993). A mixer pump was installed in SY-101 in late 1993 to prevent gases from building up in the settled solids layer, and the large episodic gas releases have since ceased (Allemann et al. 1994; Stewart et al. 1994; Brewster et al. 1995). However, the surface level of SY-101 has been increasing since at least 1995, and in recent months the level growth has shown significant and unexpected acceleration. Based on a number of observations and measurements, including data from the void fraction instrument (VFI), we have concluded that the level growth is caused largely by increased gas retention in the floating crust. In September 1998, the crust contained between about 21 and 43% void based on VFI measurements (Stewart et al. 1998). Accordingly, it is important to understand the dominant mechanisms of gas retention, why the gas retention is increasing, and whether the accelerating level increase will continue, diminish or even reverse. It is expected that the retained gas in the crust is flammable, with hydrogen as a major constituent. This gas inventory would pose a flammable gas hazard if it were to release suddenly. In May 1997, the mechanisms of bubble retention and release from crust material were the subject of a workshop. The evaluation of the crust and potential hazards assumed a more typical void of roughly 15% gas. It could be similar to

Beyond low-level activity: On a 'non-radioactive' gas mantle

Energy Technology Data Exchange (ETDEWEB)

Poljanc, Karin [Atominstitut der Osterreichischen Universitaeten, Vienna University of Technology, Stadionallee 2, 1020 Vienna (Austria); Steinhauser, Georg [Atominstitut der Osterreichischen Universitaeten, Vienna University of Technology, Stadionallee 2, 1020 Vienna (Austria)]. E-mail: georg.steinhauser@ati.ac.at; Sterba, Johannes H. [Atominstitut der Osterreichischen Universitaeten, Vienna University of Technology, Stadionallee 2, 1020 Vienna (Austria); Buchtela, Karl [Atominstitut der Osterreichischen Universitaeten, Vienna University of Technology, Stadionallee 2, 1020 Vienna (Austria); Bichler, Max [Atominstitut der Osterreichischen Universitaeten, Vienna University of Technology, Stadionallee 2, 1020 Vienna (Austria)

2007-03-01

Gas mantles for camping gas lanterns sometimes contain thorium compounds. During the last years, the use of thorium-free gas mantles has become more and more popular due to the avoidance of a radioactive heavy metal. We investigated a gas mantle type that is declared to be 'non-radioactive' and that can be bought in Austria at the moment. Methods used were Instrumental Neutron Activation Analysis (INAA), {gamma}-spectroscopy, and Liquid Scintillation Counting (LSC). We found massive thorium contents of up to 259 mg per gas mantle. Leaching experiments showed that only 0.4% of the Th but approximately 90% of the decay products of {sup 232}Th can be leached under conditions simulating sucking and chewing with human saliva. In this paper, the investigation of these gas mantles including the consideration of the environmental hazard caused by disposed mantles and the health hazard for unsuspecting consumers is presented and legal consequences are discussed for this fraud.

Analysis of Complex Marine Hazards on the Romanian Black Sea Shelf Using Combined Geophysical Methods

Science.gov (United States)

Samoila, I. V.; Radulescu, V.; Moise, G.; Diaconu, A.; Radulescu, R.

2017-12-01

Combined geophysical acquisition technologies including High Resolution 2D Seismic (HR2D), Multi-Beam Echo-Sounding (MBES), Sub-Bottom Profiling (SBP) and Magnetometry were used in the Western Black Sea (offshore Romania) to identify possible geohazards, such as gas escaping surface sediments and tectonic hazard areas up to 1 km below the seafloor. The National Project was funded by the Research and Innovation Ministry of Romania, and has taken place over 1.5 years with the purpose of creating risk maps for the surveyed pilot area. Using an array of geophysical methods and creating a workflow to identify geohazard susceptible areas on the Romanian Black Sea continental shelf is important and beneficial for future research projects. The SBP and MBES data show disturbed areas that can be interpreted as gas escapes on the surface of the seafloor, and some escapes were confirmed on the HR2D profiles. Shallow gas indicators like gas chimneys and acoustic blanking are usually delimited by vertical, sub-vertical and/or quasi-horizontal faults that mark possible hazard areas on shallow sedimentary sections. Interpreted seismic profiles show three main markers: one delimiting the Pliocene-Quaternary boundary and two for the Miocene (Upper and Lower). Vertical and quasi-horizontal faults are characteristic for the Upper Miocene, while the Lower Miocene has NW-SE horizontal faults. Faults and possible hazard areas were marked on seismic sections and were further correlated with the MBES, SBP, Magnetometry and previously recorded data, such as earthquake epicenters scattered offshore in the Western Black Sea. The main fault systems likely to cause those earthquakes also aid the migration of gas if the faults are not sealed. We observed that the gas escapes were correlated with faults described on the recent seismic profiles. Mapping hazard areas will have an important contribution to better understand the recent evolution of the Western Black Sea basin but also for projecting

Lipids and Fatty Acids in Algae: Extraction, Fractionation into Lipid Classes, and Analysis by Gas Chromatography Coupled with Flame Ionization Detector (GC-FID).

Science.gov (United States)

Guihéneuf, Freddy; Schmid, Matthias; Stengel, Dagmar B

2015-01-01

Despite the number of biochemical studies exploring algal lipids and fatty acid biosynthesis pathways and profiles, analytical methods used by phycologists for this purpose are often diverse and incompletely described. Potential confusion and potential variability of the results between studies can therefore occur due to change of protocols for lipid extraction and fractionation, as well as fatty acid methyl esters (FAME) preparation before gas chromatography (GC) analyses. Here, we describe a step-by-step procedure for the profiling of neutral and polar lipids using techniques such as solid-liquid extraction (SLE), thin-layer chromatography (TLC), and gas chromatography coupled with flame ionization detector (GC-FID). As an example, in this protocol chapter, analyses of neutral and polar lipids from the marine microalga Pavlova lutheri (an EPA/DHA-rich haptophyte) will be outlined to describe the distribution of fatty acid residues within its major lipid classes. This method has been proven to be a reliable technique to assess changes in lipid and fatty acid profiles in several other microalgal species and seaweeds.

Gas hydrates and clathrates. Flow assurance, environmental and economic perspectives and the Nigerian liquefied natural gas project

International Nuclear Information System (INIS)

Gbaruko, B.C.; Igwe, J.C.; Nwokeoma, R.C.; Gbaruko, P.N.

2007-01-01

Gas hydrates are nonstoichiometric crystalline compounds that belong to the inclusion group known as clathrates. They occur when water molecules attach themselves together through hydrogen bonding and form cavities which can be occupied by a single gas or volatile liquid molecule. Gas hydrates, asphaltenes and waxes are three major threats to flow assurance that must be well assessed by design team uptime. Gas hydrates are also looked upon as a future energy source and as a potential climate hazard. The purpose of this review is to show the chemistry and mechanism of gas hydrate formation, the problems they pose, especially to flow assurance, their system implications, their environmental and economic perspectives with respect to their prospects as storage and transport alternative to the liquefied natural gas technology. (author)

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

Science.gov (United States)

Hussein, H A; Aamer, A A

2013-01-01

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 (ppO2 values were significantly higher for Group I after 2 h and for Groups II and III after 1 h (preference range and it may be of clinical diagnostic use for up to 6 h.

46 CFR 151.50-23 - Phosphoric acid.

Science.gov (United States)

2010-10-01

... 46 Shipping 5 2010-10-01 2010-10-01 false Phosphoric acid. 151.50-23 Section 151.50-23 Shipping... BULK LIQUID HAZARDOUS MATERIAL CARGOES Special Requirements § 151.50-23 Phosphoric acid. (a) The term phosphoric acid as used in this subpart shall include, in addition to phosphoric acid, aqueous solutions of...

Dynamic safety assessment of natural gas stations using Bayesian network

NARCIS (Netherlands)

Zarei, Esmaeil; Azadeh, Ali; Khakzad Rostami, N.; Mirzaei Aliabadi, Mostafa; Mohammadfam, Iraj

2017-01-01

Pipelines are one of the most popular and effective ways of transporting hazardous materials, especially natural gas. However, the rapid development of gas pipelines and stations in urban areas has introduced a serious threat to public safety and assets. Although different methods have been

Treatment of hazardous organic wastes using silent discharge plasmas

International Nuclear Information System (INIS)

Rosocha, L.A.; Anderson, G.K.; Bechtold, L.A.; Coogan, J.J.; Heck, H.G.; Kang, M.; McCulla, W.H.; Tennant, R.A.; Wantuck, P.J.

1992-01-01

During the past two decades, interest in applying non-equilibrium plasmas to the removal of hazardous chemicals from gaseous media has been growing, in particular from heightened concerns over the pollution of our environment and a growing body of environmental regulations. At the Los Alamos National Laboratory, we are currently engaged in a project to develop non-equilibrium plasma technology for hazardous waste treatment. Our present focus is on dielectric-barrier discharges, which are historically called silent electrical discharges. This type of plasma is also named a silent discharge plasma (SDP). We have chosen this method due to its potential for high energy efficiency, its scientific and technological maturity, and its scalability. The SDP process has been demonstrated to be reliable and economical for the industrial-scale synthesis of ozone, where municipal water treatment plants frequently require the on-site generation of thousands of kilograins per day (Eliasson ampersand Kogelschatz). The related methods of corona processing are presently the focus of work at other institutions, particularly for flue gas processing. Both SDP and corona processes are characterized by the production of large quantities of highly reactive free radicals, especially atomic oxygen O(3P) and the hydroxyl OH, in the gaseous medium and their subsequent reaction with contaminants. Our primary objective is to convert hazardous or toxic chemicals into non-hazardous compounds or into materials which are more amenable to treatment. In the ideal case, the hazardous wastes are destructively oxidized to simpler, non-hazardous compounds plus CO2 and H2O. Sometimes the reaction products are still potentially hazardous, but are easily treated by conventional methods to yield non-hazardous products

Hazard identification studies applied to oil pipelines

Energy Technology Data Exchange (ETDEWEB)

Savio, Augusto; Alpert, Melina L. [TECNA S.A., Buenos Aires (Argentina)], e-mail: asavio@tecna.com, e-mail: malpert@tecna.com

2008-07-01

In order to assess risks inherent to an Oil Pipeline, it is imperative to analyze what happens 'outside the process'. HAZID (HAZard IDentification) studies are mainly carried out for this purpose. HAZID is a formal study which identifies hazards and risks associated to an operation or facility and enable its acceptability assessment. It is a brainstorming exercise guided by a typical 'Checklist', divided into four Sections: External, Facilities and Health Hazards and Issues pertaining to Project Execution, which are further subdivided into Hazard Categories. For each Category, there are 'Guide-words' and 'Prompts'. Even if an Oil Pipeline Risk Assessment can be performed by means of the above referred 'Checklist', carrying out the actual process can become lengthy and annoying due to the lack of specificity. This work aims at presenting the most suitable 'Checklist' for the identification of Oil Pipeline Risk Assessment, although it could be used for Gas Pipeline Risk Assessment too. Prepared ad hoc, this list, is based on the spill causes established by CONCAWE (CONservation of Clean Air Water in Europe). Performing Oil Pipeline Risk Assessment by means of specially formulated Checklist enables the Study Team to easily identify risks, shortens execution time and provides both accuracy and specificity. (author)

Determination of homovanillic acid and vanillylmandelic acid in urine of autistic children by gas chromatography/mass spectrometry.

Science.gov (United States)

Kałuzna-Czaplińska, Joanna; Socha, Ewa; Rynkowski, Jacek

2010-09-01

Studies suggest dopamine nervous systems are involved in the pathogenesis of autistic disorder. Quantification of urinary homovanillic acid (HVA) and vanillylmandelic acid (VMA) can be a very important tool in the study of disorders of dopamine metabolism in autistic children. The urine specimens were collected from 20 autistic children and 36 neurologically normal children. Urinary HVA and VMA were simultaneously analyzed by gas chromatography-mass spectrometry. The method involves extraction of HVA and VMA from urinary samples and derivatization to N,O-bis(trimethylsilyl)trifluoroacetamide derivatives. The detection limits are 0.15 microg/mL and 0.23 microg/mL for VMA and HVA, respectively. The levels of HVA and VMA were higher in the urine of autistic children (28.8+/-15.5 micromol/mmol creatinine and 22.2+/-13.0 micromol/mmol creatinine, respectively) compared with those of the generally healthy children (4.6+/-0.7 micromol/mmol creatinine for HVA and 3.8+/-0.6 micromol/mmol creatinine for VMA). We proposed a simple, rapid method for a routine analysis of human urine to detect HVA and VMA related to an abnormal functional imbalance of the dopamine system, and showed our experience of application of this method to patients with a diagnosis of autism spectrum disorders. These results suggest significant differences in the levels of HVA and VMA between autistic and healthy children.

46 CFR 151.50-21 - Sulfuric acid.

Science.gov (United States)

2010-10-01

... 46 Shipping 5 2010-10-01 2010-10-01 false Sulfuric acid. 151.50-21 Section 151.50-21 Shipping... BULK LIQUID HAZARDOUS MATERIAL CARGOES Special Requirements § 151.50-21 Sulfuric acid. (a) How sulfuric acid may be carried. (1) Sulfuric acid of concentration of 77.5 percent (1.7019 specific gravity) (59.8...

Separation behavior of octadecadienoic acid isomers and identification of cis- and trans-isomers using gas chromatography.

Science.gov (United States)

Shibamoto, Shigeaki; Gooley, Andrew; Yamamoto, Kouhei

2015-01-01

Using a strongly polar cyanopropyl capillary column we have investigated the gas chromatography (GC) separation behaviors of 24 octadecadienoic acid methyl ester (18:2ME) isomers compared against saturated methyl stearate (18:0ME) and arachidic acid methyl ester (20:0ME), and the dependency on the GC column temperature. The 24 isomers were obtained by performing cis-to trans-isomerization of six regioisomers: five of the 18:2ME isomers were prepared by the partial reduction of methyl α-linolenate and methyl γ-linolenate C18 trienoic acids with different double bond positions, whereas the sixth isomer, 18:2ME (c5, c9), was obtained from a raw constituent fatty acid methyl ester (FAME) sample extracted from Japanese yew seeds. There are no reference standards commercially available for 18:2ME isomers, and in elucidating the elution order of these isomers this study should help the future identification of cis- and trans-type of 18:2ME. We also report the identification method of cis- and trans-type of FAME using equivalent chain lengths and attempt the identification of cis- and trans-type of 18:2ME isomers from partially hydrogenated canola oil.

Disaster and hazard prevention research

Energy Technology Data Exchange (ETDEWEB)

Kim, Bok Youn; Kang, Chang Hee; Jo, Young Do; Lim, Sang Taek [Korea Institute of Geology Mining and Materials, Taejon (Korea, Republic of)

1996-12-01

It is third project year on `Application of mobile diesel equipment in underground mines` for providing appropriate measures to improve underground working environment contaminated by the diesel exhaust pollutants. The result of disaster and hazard prevention research is as follows ; 1) There are three categories of possible disaster of hazard in workings where diesel equipment are operating : a) exhausting pollutants, b) mine fire, c) other causes. 2) Workings employing diesel equipment should be properly ventilated all the time to maintain the gas concentration bellow the permissible level. 3) Major cause of fire is known as the high engine temperature by heavy duty and rupture of hydraulic hoses or fuel pipes and fuel spillage. So, sound engine maintenance and workers` train is essential matter to prevent fire outbreak. 4) By simulating the expected mine fire, The proper measures can be provided in actual fire. 5) Fuel and other are recommended to be stored at surface and, when the storage installed in underground, all the safety regulation should be kept strictly. (author). 6 tabs., 3 figs.

Quantitative analysis of fatty-acid-based biofuels produced by wild-type and genetically engineered cyanobacteria by gas chromatography-mass spectrometry.

Science.gov (United States)

Guan, Wenna; Zhao, Hui; Lu, Xuefeng; Wang, Cong; Yang, Menglong; Bai, Fali

2011-11-11

Simple and rapid quantitative determination of fatty-acid-based biofuels is greatly important for the study of genetic engineering progress for biofuels production by microalgae. Ideal biofuels produced from biological systems should be chemically similar to petroleum, like fatty-acid-based molecules including free fatty acids, fatty acid methyl esters, fatty acid ethyl esters, fatty alcohols and fatty alkanes. This study founded a gas chromatography-mass spectrometry (GC-MS) method for simultaneous quantification of seven free fatty acids, nine fatty acid methyl esters, five fatty acid ethyl esters, five fatty alcohols and three fatty alkanes produced by wild-type Synechocystis PCC 6803 and its genetically engineered strain. Data obtained from GC-MS analyses were quantified using internal standard peak area comparisons. The linearity, limit of detection (LOD) and precision (RSD) of the method were evaluated. The results demonstrated that fatty-acid-based biofuels can be directly determined by GC-MS without derivation. Therefore, rapid and reliable quantitative analysis of fatty-acid-based biofuels produced by wild-type and genetically engineered cyanobacteria can be achieved using the GC-MS method founded in this work. Copyright © 2011 Elsevier B.V. All rights reserved.

Incineration and flue gas cleaning in China - a Review

International Nuclear Information System (INIS)

Buekens, Alfons; Yan, Mi; Jiang, Xuguan; Li, Xiaodong; Lu, Shengyong; Chi, Yong; Yan, Jianhua; Cen, Kefa

2010-01-01

Waste incineration is rapidly developing in China. Different technologies are proposed for Municipal Solid Waste (MSW), Hazardous Waste (HW), and Medical Waste (MW). The required technologies are either imported, or developed locally. Some data are cited to illustrate these rapid developments. Incinerator flue gas arises at rather limited scale (10,000-100,000 Nm 3 /h), compared to power generation, yet the number of pollutants to be counted with is huge: dust and grit, acid gases, NO x , selected heavy metals, aerosols and nanoparticles, Polycyclic Aromatic Hydrocarbons, and dioxins. Major options in flue gas cleaning can be derived from Best Available Technologies (BAT), as were developed in the European Union. Hence, E.U. practice is analyzed in some detail, by considering the present situation in selected E.U. countries (Germany, Sweden, the Netherlands, Denmark, Belgium). A comparison is made with China. Also, the situation in Japan is examined. Based on this wide experience, a number of technical suggestions regarding incineration, flue gas cleaning, and emission control are formulated. Also, the possibility of co incineration is considered. Starting from the particular experience of Zhejiang University (as a designer of Fluid Bed and Rotary Kiln plant, with large experience in Fluid Bed processes, coal firing, gasification and pyrolysis, and actively monitoring thermal units throughout China) some specific Case Studies are examined, e.g., a fluidized bed incinerator and its gas cleaning system (MSWI and HWI from ITPE). Some attention is paid to the potential threats in China from uncontrolled combustion sources. As a conclusion, some recommendations are formulated regarding flue gas cleaning in Developing Nations at large and in China in particular. (author)

Transportation of Hazardous Materials Emergency Preparedness Hazards Assessment

Energy Technology Data Exchange (ETDEWEB)

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.

Transportation of Hazardous Materials Emergency Preparedness Hazards Assessment

International Nuclear Information System (INIS)

Blanchard, A.

2000-01-01

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

Transportation of hazardous materials emergency preparedness hazards assessment

International Nuclear Information System (INIS)

Blanchard, A.

2000-01-01

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

Radon -- an environmental hazard

International Nuclear Information System (INIS)

Faheem, M.; Rahman, R.; Rahman, S.; Matiullah

2005-01-01

Humans have always been exposed throughout its period of experience to naturally occurring sources of ionizing radiation or natural background radiation, It is an established fact that even these low background doses are harmful to man and cause increased cancer risk. About half of our radiation comes from radon, a radioactive gas coming from normal materials in the ground. Several building materials such as granite, bricks, sand, cement etc., contain uranium in various amounts. The radioactive gas /sup 222/Rn produced in these materials due to decay of 226Ra is transported to indoor air through diffusion and convective flow. It seeps out of soil and rocks, well water, building materials and other sources at a varied rate. Amongst the naturally occurring radioisotopes, radon is the most harmful one that can be a cause of lung cancer. Radon isotopes are born by the decay of radium and radium production in turns comes from uranium or thorium decay. For humans the greatest importance among Radon isotopes is attributed to /sup 222/Rn because it is the longest lived of the three naturally produced isotopes. Drinking water also poses a threat. Radon gas is dissolved in water and is released into the air via water faucets, showerheads, etc. the lack of understanding has so far lead to speculative estimates of pollutant related health hazards. (author)

DWPF Melter Off-Gas Flammability Assessment for Sludge Batch 9

Energy Technology Data Exchange (ETDEWEB)

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

2016-07-11

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

Modelling risk in high hazard operations : Integrating technical, organisational and cultural factors

NARCIS (Netherlands)

Ale, B.J.M.; Hanea, D.M.; Sillem, S.; Lin, P.H.; Van Gulijk, C.; Hudson, P.T.W.

2012-01-01

Recent disasters in high hazard industries such as Oil and Gas Exploration (The Deepwater Horizon) and Petrochemical production (Texas City) have been found to have causes that range from direct technical failures through organizational shortcomings right up to weak regulation and inappropriate

An approach for estimating toxic releases of H2S-containing natural gas.

Science.gov (United States)

Jianwen, Zhang; Da, Lei; Wenxing, Feng

2014-01-15

China is well known being rich in sulfurous natural gas with huge deposits widely distributed all over the country. Due to the toxic nature, the release of hydrogen sulfide-containing natural gas from the pipelines intends to impose serious threats to the human, society and environment around the release sources. CFD algorithm is adopted to simulate the dispersion process of gas, and the results prove that Gaussian plume model is suitable for determining the affected region of the well blowout of sulfide hydrogen-containing natural gas. In accordance with the analysis of release scenarios, the present study proposes a new approach for estimating the risk of hydrogen sulfide poisoning hazards, as caused by sulfide-hydrogen-containing natural gas releases. Historical accident-statistical data from the EGIG (European Gas Pipeline Incident Data Group) and the Britain Gas Transco are integrated into the approach. Also, the dose-load effect is introduced to exploit the hazards' effects by two essential parameters - toxic concentration and exposure time. The approach was applied to three release scenarios occurring on the East-Sichuan Gas Transportation Project, and the individual risk and societal risk are classified and discussed. Results show that societal risk varies significantly with different factors, including population density, distance from pipeline, operating conditions and so on. Concerning the dispersion process of hazardous gas, available safe egress time was studied from the perspective of individual fatality risks. The present approach can provide reliable support for the safety management and maintenance of natural gas pipelines as well as evacuations that may occur after release incidents. Copyright © 2013 Elsevier B.V. All rights reserved.

Enhanced levels of atmospheric low-molecular weight monocarboxylic acids in gas and particulates over Mt. Tai, North China, during field burning of agricultural wastes

Science.gov (United States)

Mochizuki, Tomoki; Kawamura, Kimitaka; Nakamura, Shinnosuke; Kanaya, Yugo; Wang, Zifa

2017-12-01

To understand the source and atmospheric behaviour of low molecular weight monocarboxylic acids (monoacids), gaseous (G) and particulate (P) organic acids were collected at the summit of Mt. Tai in the North China Plain (NCP) during field burning of agricultural waste (wheat straw). Particulate organic acids were collected with neutral quartz filter whereas gaseous organic acids were collected with KOH-impregnated quartz filter. Normal (C1-C10), branched (iC4-iC6), hydroxy (lactic and glycolic), and aromatic (benzoic) monoacids were determined with a capillary gas chromatography employing p-bromophenacyl esters. We found acetic acid as the most abundant gas-phase species whereas formic acid is the dominant particle-phase species. Concentrations of formic (G/P 1 570/1 410 ng m-3) and acetic (3 960/1 120 ng m-3) acids significantly increased during the enhanced field burning of agricultural wastes. Concentrations of formic and acetic acids in daytime were found to increase in both G and P phases with those of K+, a field-burning tracer (r = 0.32-0.64). Primary emission and secondary formation of acetic acid is linked with field burning of agricultural wastes. In addition, we found that particle-phase fractions (Fp = P/(G + P)) of formic (0.50) and acetic (0.31) acids are significantly high, indicating that semi-volatile organic acids largely exist as particles. Field burning of agricultural wastes may play an important role in the formation of particulate monoacids in the NCP. High levels (917 ng m-3) of particle-phase lactic acid, which is characteristic of microorganisms, suggest that microbial activity associated with terrestrial ecosystem significantly contributes to the formation of organic aerosols.

Adsorption and reaction mechanism of arsenic vapors over γ-Al2O3 in the simulated flue gas containing acid gases.

Science.gov (United States)

Hu, Hongyun; Chen, Dunkui; Liu, Huan; Yang, Yuhan; Cai, Hexun; Shen, Junhao; Yao, Hong

2017-08-01

Arsenic emission from fuel combustion and metal smelting flue gas causes serious pollution. Addition of sorbents is a promising way for the arsenic capture from high temperature flue gas. However, it is difficult to remove arsenic from SO 2 /HCl-rich flue gas due to the competitive reaction of the sorbents with arsenic and these acid gases. To solve this problem, arsenic adsorption over γ-Al 2 O 3 was studied in this work to evaluate its adsorption mechanism, resistance to acid gases as well as regeneration behavior. The results show that γ-Al 2 O 3 had good resistance to acid gases and the arsenic adsorption by γ-Al 2 O 3 could be effectively carried out at a wide temperature range between 573 and 1023 K. Nevertheless, adsorption at higher-temperature (like 1173 K) leaded to the decrease of surface area and the rearrangement of crystal structure of γ-Al 2 O 3 , reducing the active sites for arsenic adsorption. The adsorption of arsenic was confirmed to occur at different active sites in γ-Al 2 O 3 by forming various adsorbed species. Increasing temperature facilitated arsenic transformation into more stable chemisorbed As 3+ and As 5+ which were difficult to remove through thermal treatment regeneration. Fortunately, the regeneration of spent γ-Al 2 O 3 could be well performed using NaOH solution. Copyright © 2017 Elsevier Ltd. All rights reserved.

Trade-off in emissions of acid gas pollutants and of carbon dioxide in fossil fuel power plants with carbon capture

International Nuclear Information System (INIS)

Tzimas, Evangelos; Mercier, Arnaud; Cormos, Calin-Cristian; Peteves, Stathis D.

2007-01-01

This paper investigates the impact of capture of carbon dioxide (CO 2 ) from fossil fuel power plants on the emissions of nitrogen oxides (NO X ) and sulphur oxides (SO X ), which are acid gas pollutants. This was done by estimating the emissions of these chemical compounds from natural gas combined cycle and pulverized coal plants, equipped with post-combustion carbon capture technology for the removal of CO 2 from their flue gases, and comparing them with the emissions of similar plants without CO 2 capture. The capture of CO 2 is not likely to increase the emissions of acid gas pollutants from individual power plants; on the contrary, some NO X and SO X will also be removed during the capture of CO 2 . The large-scale implementation of carbon capture is however likely to increase the emission levels of NO X from the power sector due to the reduced efficiency of power plants equipped with capture technologies. Furthermore, SO X emissions from coal plants should be decreased to avoid significant losses of the chemicals that are used to capture CO 2 . The increase in the quantity of NO X emissions will be however low, estimated at 5% for the natural gas power plant park and 24% for the coal plants, while the emissions of SO X from coal fired plants will be reduced by as much as 99% when at least 80% of the CO 2 generated will be captured

Possible combustion hazards in 3013 plutonium waste container

International Nuclear Information System (INIS)

Sherman, M.P.

1999-01-01

Are there combustion hazards in plutonium-contaminated waste containers caused by combustible gas generation? Current gas generation models in which the only reaction considered is radiolysis must inevitably predict eventual complete dissociation of any water present into hydrogen and oxygen. Waste prepared for the 3013 container should be less subject to this problem because organic material and most of the absorbed water should have been removed. Depending on the waste form, moisture content, organic content, temperature, and container material, the pressure rise due to gas generation will be bounded by backreactions, recombination of the hydrogen and oxygen, absorption of the oxygen by plutonium oxide, and possibly other chemical reactions. Examination of a variety of food pack waste containers at Los Alamos National Laboratory (LANL) has shown little pressure rise, indeed often subatmospheric pressures. In a few cases large hydrogen concentrations up to 47% mole fraction were observed, but with negligible oxygen content. The only fuel seen in significant quantities was H 2 and, in one case, CO; the only oxidizer seen in significant quantities was O 2 . Considerable work on measuring gas generation is being done at Westinghouse Savannah River Company and LANL. In a mixture of H 2 , O 2 , and other diluent gases, if the hydrogen concentration is below the value at the lean flammability limit, or if the oxygen concentration is below that at the rich flammability limit, a flame will not propagate from an ignition source. Assuming H 2 is the only fuel present in significant quantities, a mixture leaner than the lean limit will get only leaner if mixed with air and is therefore no combustion hazard. However, when a mixture containing large amounts of H 2 is nonflammable because there is insufficient O 2 , there is a hazard. If the mixture should leak into a volume containing O 2 , or the container is opened into the surrounding air, the mixture will pass through the

Influence of gas-particle partitioning on ammonia and nitric acid fluxes above a deciduous forest in the Midwestern USA

DEFF Research Database (Denmark)

Hansen, Kristina; Sørensen, Lise Lotte; Hornsby, Karen E.

to bi-directionality of the flux, and the dynamics of the chemical gas/aerosol equilibrium of NH3 and HNO3 (or other atmospheric acids) with aerosol-phase ammonium (NH4+) and nitrate (NO3-). NH3 and HNO3 are both very reactive and typically exhibit higher deposition velocities than aerosol NH4...... 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...

Comparative alternative materials assessment to screen toxicity hazards in the life cycle of CIGS thin film photovoltaics

Energy Technology Data Exchange (ETDEWEB)

Eisenberg, Daniel A.; Yu, Mengjing; Lam, Carl W. [University of California, Davis, 1 Shields Avenue, Davis, CA 95616 (United States); Ogunseitan, Oladele A. [University of California, Irvine, Irvine, CA 92697 (United States); Schoenung, Julie M., E-mail: jmschoenung@ucdavis.edu [University of California, Davis, 1 Shields Avenue, Davis, CA 95616 (United States)

2013-09-15

Highlights: • Comparative alternatives assessment of thin film manufacturing technologies. • Development of chemical alternatives assessment in a life cycle context. • Screening of manufacturing and solar cell hazardous substances simultaneously. -- Abstract: Copper–indium–gallium–selenium–sulfide (CIGS) thin film photovoltaics are increasingly penetrating the market supply for consumer solar panels. Although CIGS is attractive for producing less greenhouse gas emissions than fossil-fuel based energy sources, CIGS manufacturing processes and solar cell devices use hazardous materials that should be carefully considered in evaluating and comparing net environmental benefits of energy products. Through this research, we present a case study on the toxicity hazards associated with alternative materials selection for CIGS manufacturing. We applied two numeric models, The Green Screen for Safer Chemicals™ and the Toxic Potential Indicator. To improve the sensitivity of the model outputs, we developed a novel, life cycle thinking based hazard assessment method that facilitates the projection of hazards throughout material life cycles. Our results show that the least hazardous CIGS solar cell device and manufacturing protocol consist of a titanium substrate, molybdenum metal back electrode, CuInS{sub 2} p-type absorber deposited by spray pyrolysis, ZnS buffer deposited by spray ion layer gas reduction, ZnO:Ga transparent conducting oxide (TCO) deposited by sputtering, and the encapsulant polydimethylsiloxane.

Investigation of secondary formation of formic acid: urban environment vs. oil and gas producing region

Science.gov (United States)

Yuan, B.; Veres, P. R.; Warneke, C.; Roberts, J. M.; Gilman, J. B.; Koss, A.; Edwards, P. M.; Graus, M.; Kuster, W. C.; Li, S.-M.; Wild, R. J.; Brown, S. S.; Dubé, W. P.; Lerner, B. M.; Williams, E. J.; Johnson, J. E.; Quinn, P. K.; Bates, T. S.; Lefer, B.; Hayes, P. L.; Jimenez, J. L.; Weber, R. J.; Zamora, R.; Ervens, B.; Millet, D. B.; Rappenglück, B.; de Gouw, J. A.

2015-02-01

Formic acid (HCOOH) is one of the most abundant carboxylic acids in the atmosphere. However, current photochemical models cannot fully explain observed concentrations and in particular secondary formation of formic acid across various environments. In this work, formic acid measurements made at an urban receptor site (Pasadena) in June-July 2010 during CalNex (California Research at the Nexus of Air Quality and Climate Change) and a site in an oil and gas producing region (Uintah Basin) in January-February 2013 during UBWOS 2013 (Uintah Basin Winter Ozone Studies) will be discussed. Although the VOC (volatile organic compounds) compositions differed dramatically at the two sites, measured formic acid concentrations were comparable: 2.3 ± 1.3 in UBWOS 2013 and 2.0 ± 1.0 ppb in CalNex. We determine that concentrations of formic acid at both sites were dominated by secondary formation (> 99%). A constrained box model using the Master Chemical Mechanism (MCM v3.2) underestimates the measured formic acid concentrations drastically at both sites (by a factor of > 10). Compared to the original MCM model that includes only ozonolysis of unsaturated organic compounds and OH oxidation of acetylene, when we updated yields of ozonolysis of alkenes and included OH oxidation of isoprene, vinyl alcohol chemistry, reaction of formaldehyde with HO2, oxidation of aromatics, and reaction of CH3O2 with OH, the model predictions for formic acid were improved by a factor of 6.4 in UBWOS 2013 and 4.5 in CalNex, respectively. A comparison of measured and modeled HCOOH/acetone ratios is used to evaluate the model performance for formic acid. We conclude that the modified chemical mechanism can explain 19 and 45% of secondary formation of formic acid in UBWOS 2013 and CalNex, respectively. The contributions from aqueous reactions in aerosol and heterogeneous reactions on aerosol surface to formic acid are estimated to be 0-6 and 0-5% in UBWOS 2013 and CalNex, respectively. We observe that

Recovering energy and materials from hazardous waste

Energy Technology Data Exchange (ETDEWEB)

Anon.

2003-12-01

The tannery industry faces growing environmental concerns because of the high hazardous metal content of its process waste. The formation, during the tanning process, of the highly toxic hexavalent chromium precludes the use of conventional thermal incineration processes. Borge Tannery in Norway, which processes 600 cattle hides per day, has solved the problem by using new PyroArc technology. The PyroArc waste processing plant can treat all of the tannery's production wastes, transforming them into useful products such as fuel gas and re-usable metal. The fuel gas consists mainly of carbon monoxide, hydrogen and nitrogen, and has a calorific value of about 4 MJ/Nm{sub 3}. About 65-70% of the energy content of the source material (waste or biomass) is recovered in the gas, and this is used to produce steam and/or electricity in a gas engine with a capacity of 580 kW. A further 20-25% of the initial energy content is recovered as heat or low-pressure steam. The plant is designed to be self-sufficient in energy (1.5 MW) and to meet the tannery's maximum requirements for hot water and steam. (UK)

Hazard function theory for nonstationary natural hazards

Science.gov (United States)

Read, L.; Vogel, R. M.

2015-12-01

Studies from the natural hazards literature indicate that many natural processes, including wind speeds, landslides, wildfires, precipitation, streamflow and earthquakes, show evidence of nonstationary behavior such as trends in magnitudes through time. Traditional probabilistic analysis of natural hazards based on partial duration series (PDS) generally assumes stationarity in the magnitudes and arrivals of events, i.e. that the probability of exceedance is constant through time. Given evidence of trends and the consequent expected growth in devastating impacts from natural hazards across the world, new methods are needed to characterize their probabilistic behavior. The 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 and reliabilities associated with nonstationary event series. This work investigates the suitability of HFA to characterize nonstationary natural hazards whose PDS magnitudes are assumed to follow the widely applied Poisson-GP model. We derive a 2-parameter Generalized Pareto hazard model 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 event series x, with corresponding failure time series t, should have application to a wide class of natural hazards.

Hazard function theory for nonstationary natural hazards

Science.gov (United States)

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.

Mapping mountain torrent hazards in the Hexi Corridor using an evidential reasoning approach

Science.gov (United States)

Ran, Youhua; Liu, Jinpeng; Tian, Feng; Wang, Dekai

2017-02-01

The Hexi Corridor is an important part of the Silk Road Economic Belt and a crucial channel for westward development in China. Many important national engineering projects pass through the corridor, such as highways, railways, and the West-to-East Gas Pipeline. The frequent torrent disasters greatly impact the security of infrastructure and human safety. In this study, an evidential reasoning approach based on Dempster-Shafer theory is proposed for mapping mountain torrent hazards in the Hexi Corridor. A torrent hazard map for the Hexi Corridor was generated by integrating the driving factors of mountain torrent disasters including precipitation, terrain, flow concentration processes, and the vegetation fraction. The results show that the capability of the proposed method is satisfactory. The torrent hazard map shows that there is high potential torrent hazard in the central and southeastern Hexi Corridor. The results are useful for engineering planning support and resource protection in the Hexi Corridor. Further efforts are discussed for improving torrent hazard mapping and prediction.

High efficient ethanol and VFAs production from gas fermentation: effect of acetate, gas and inoculum microbial composition

DEFF Research Database (Denmark)

El-Gammal, Maie; Abou-Shanab, Reda; Angelidaki, Irini

2017-01-01

In bioindustry, syngas fermentation is a promising technology for biofuel production without the use of plant biomass as sugar-based feedstock. The aim of this study was to identify optimal conditions for high efficient ethanol and volatile fatty acids (VFA) production from synthetic gas...... fatty acids and ethanol was achieved by the pure culture (Clostridium ragsdalei). Depending on the headspace gas composition, VFA concentrations were up to 300% higher after fermentation with Clostridium ragsdalei compared to fermentation with mixed culture. The preferred gas composition with respect...

The criteria of critical runaway and stable temperatures of catalytic decomposition of hydrogen peroxide in the presence of hydrochloric acid

International Nuclear Information System (INIS)

Lu, K.-T.; Yang, C.-C.; Lin, P.-C.

2006-01-01

The hydrogen peroxide and hydrochloric acid are used in close proximity in the computer chip manufacture. The hydrochloric acid catalyzes an exothermic decomposition of hydrogen peroxide into oxygen and water. The accumulation of heat and non-condensable gas increases temperature and pressure in this reaction process always lead to runaway reaction and accident owing to inadvertent mixing. Thus, the chemical reaction hazard has to be clearly identified. Its critical runaway temperatures and unstable reaction criteria in this reaction process have to be determined urgently. In this investigation, we estimated its kinetic parameters at various volumetric ratios of the hydrogen peroxide to hydrochloric acid. Then, used these kinetic parameters to evaluate their critical temperatures and stable criteria in each reaction processes. The analytic results are important and useful for the design of safety system in the computer chip manufacture

40 CFR 270.22 - Specific part B information requirements for boilers and industrial furnaces burning hazardous...

Science.gov (United States)

2010-07-01

... requirements for boilers and industrial furnaces burning hazardous waste. 270.22 Section 270.22 Protection of... requirements for boilers and industrial furnaces burning hazardous waste. When an owner or operator of a cement kiln, lightweight aggregate kiln, solid fuel boiler, liquid fuel boiler, or hydrochloric acid...

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

Energy Technology Data Exchange (ETDEWEB)

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.

High efficient ethanol and VFAs production from gas fermentation: effect of acetate, gas and inoculum microbial composition

DEFF Research Database (Denmark)

El-Gammal, Maie; Abou-Shanab, Reda; Angelidaki, Irini

2017-01-01

In bioindustry, syngas fermentation is a promising technology for biofuel production without the use of plant biomass as sugar-based feedstock. The aim of this study was to identify optimal conditions for high efficient ethanol and volatile fatty acids (VFA) production from synthetic gas fermenta......In bioindustry, syngas fermentation is a promising technology for biofuel production without the use of plant biomass as sugar-based feedstock. The aim of this study was to identify optimal conditions for high efficient ethanol and volatile fatty acids (VFA) production from synthetic gas...... fatty acids and ethanol was achieved by the pure culture (Clostridium ragsdalei). Depending on the headspace gas composition, VFA concentrations were up to 300% higher after fermentation with Clostridium ragsdalei compared to fermentation with mixed culture. The preferred gas composition with respect...... to highest VFA concentration was pure CO (100%) regardless of microbial composition of the inoculum and media composition. The addition of acetate had a negative impact on the VFA formation which was depending on the initial gas composition in head space....

Evaluation of extractant-coated magnetic microparticles for the recovery of hazardous metals from waste solution

International Nuclear Information System (INIS)

Kaminski, M. D.

1998-01-01

A magnetically assisted chemical separation (MACS) process was developed earlier at Argonne National Laboratory (ANL). This compact process was designed for the separation of transuranics (TRU) and radionuclides from the liquid waste streams that exist at many DOE sites, with an overall reduction in waste volume requiring disposal. The MACS process combines the selectivity afforded by solvent extractant/ion exchange materials with magnetic separation to provide an efficient chemical separation. Recently, the MACS process has been evaluated with acidic organophosphorus extractants for hazardous metal recovery from waste solutions. Moreover, process scale-up design issues have been addressed with respect to particle filtration and recovery. Two acidic organophosphorus compounds have been investigated for hazardous metal recovery, bis(2,4,4-trimethylpentyl) phosphinic acid (Cyanexreg-sign 272) and bis(2,4,4-trimethylpentyl) dithiophosphinic acid (Cyanexreg-sign 301). Coated onto magnetic microparticles, these extractants demonstrated superior recovery of hazardous metals from solution, relative to what was expected on the basis of results from solvent extraction experiments. The results illustrate the diverse applications of MACS technology for dilute waste streams. Preliminary process scale-up experiments with a high-gradient magnetic separator at Oak Ridge National Laboratory have revealed that very low microparticle loss rates are possible

Characterizing cemented TRU waste for RCRA hazardous constituents

International Nuclear Information System (INIS)

Yeamans, D.R.; Betts, S.E.; Bodenstein, S.A.

1996-01-01

Los Alamos National Laboratory (LANL) has characterized drums of solidified transuranic (TRU) waste from four major waste streams. The data will help the State of New Mexico determine whether or not to issue a no-migration variance of the Waste Isolation Pilot Plant (WIPP) so that WIPP can receive and dispose of waste. The need to characterize TRU waste stored at LANL is driven by two additional factors: (1) the LANL RCRA Waste Analysis Plan for EPA compliant safe storage of hazardous waste; (2) the WIPP Waste Acceptance Criteria (WAC) The LANL characterization program includes headspace gas analysis, radioassay and radiography for all drums and solids sampling on a random selection of drums from each waste stream. Data are presented showing that the only identified non-metal RCRA hazardous component of the waste is methanol

Hazards assessment for the Hazardous Waste Storage Facility

International Nuclear Information System (INIS)

Knudsen, J.K.; Calley, M.B.

1994-04-01

This report documents the hazards assessment for the Hazardous Waste Storage Facility (HWSF) located at the Idaho National Engineering Laboratory. The hazards assessment was performed to ensure that this facility complies with DOE and company requirements pertaining to emergency planning and preparedness for operational emergencies. The hazards assessment identifies and analyzes hazards that are significant enough to warrant consideration in a facility's operational emergency management program. The area surrounding HWSF, the buildings and structures at HWSF, and the processes used at HWSF are described in this report. All nonradiological hazardous materials at the HWSF were identified (radiological hazardous materials are not stored at HWSF) and screened against threshold quantities according to DOE Order 5500.3A guidance. Two of the identified hazardous materials exceeded their specified threshold quantity. This report discusses the potential release scenarios and consequences associated with an accidental release for each of the two identified hazardous materials, lead and mercury. Emergency considerations, such as emergency planning zones, emergency classes, protective actions, and emergency action levels, are also discussed based on the analysis of potential consequences. Evaluation of the potential consequences indicated that the highest emergency class for operational emergencies at the HWSF would be a Site Area Emergency

An approach for estimating toxic releases of H{sub 2}S-containing natural gas

Energy Technology Data Exchange (ETDEWEB)

Jianwen, Zhang, E-mail: zhangjw@mail.buct.edu.cn [Lab of Fluid Flow and Heat Transfer, Beijing University of Chemical Technology, Beijing 100029 (China); Institute of Safety Management, Beijing University of Chemical Technology, Beijing 100029 (China); Da, Lei [Lab of Fluid Flow and Heat Transfer, Beijing University of Chemical Technology, Beijing 100029 (China); College of Mechanical and Electrical Engineering, Beijing University of Chemical Technology, Beijing 100029 (China); Wenxing, Feng [Pipeline Research Center of PetroChina Company Lmited, 51 Golden Road, Langfang 065000 (China)

2014-01-15

Highlights: • Behavior of H{sub 2}S-containing natural gas exhibits appearance of neutral gas by CFD. • The poisoning hazards of H{sub 2}S by gas pipeline releases are successfully estimated. • An assessment method for available safe egress time is proposed. -- Abstract: China is well known being rich in sulfurous natural gas with huge deposits widely distributed all over the country. Due to the toxic nature, the release of hydrogen sulfide-containing natural gas from the pipelines intends to impose serious threats to the human, society and environment around the release sources. CFD algorithm is adopted to simulate the dispersion process of gas, and the results prove that Gaussian plume model is suitable for determining the affected region of the well blowout of sulfide hydrogen-containing natural gas. In accordance with the analysis of release scenarios, the present study proposes a new approach for estimating the risk of hydrogen sulfide poisoning hazards, as caused by sulfide-hydrogen-containing natural gas releases. Historical accident-statistical data from the EGIG (European Gas Pipeline Incident Data Group) and the Britain Gas Transco are integrated into the approach. Also, the dose-load effect is introduced to exploit the hazards’ effects by two essential parameters – toxic concentration and exposure time. The approach was applied to three release scenarios occurring on the East-Sichuan Gas Transportation Project, and the individual risk and societal risk are classified and discussed. Results show that societal risk varies significantly with different factors, including population density, distance from pipeline, operating conditions and so on. Concerning the dispersion process of hazardous gas, available safe egress time was studied from the perspective of individual fatality risks. The present approach can provide reliable support for the safety management and maintenance of natural gas pipelines as well as evacuations that may occur after

Docosahexaenoic acid is an independent predictor of all-cause mortality in hemodialysis patients.

Science.gov (United States)

Hamazaki, Kei; Terashima, Yoshihiro; Itomura, Miho; Sawazaki, Shigeki; Inagaki, Hitoshi; Kuroda, Masahiro; Tomita, Shin; Hirata, Hitoshi; Inadera, Hidekuni; Hamazaki, Tomohito

2011-01-01

Dietary n-3 polyunsaturated fatty acids (PUFAs), docosahexaenoic acid (DHA) and eicosapentaenoic acid have been shown to reduce cardiovascular mortality. Patients on hemodialysis (HD) have a very high mortality from cardiovascular disease. Fish consumption reduces all-cause mortality in patients on HD. Moreover, n-3 PUFAs, especially DHA levels in red blood cells (RBCs), are associated with arteriosclerosis in patients on HD. The aim of this study was to determine whether DHA levels in RBCs predict the mortality of patients on HD in a prospective cohort study. A cohort of 176 patients (64.1 ± 12.0 (mean ± SD) years of age, 96 men and 80 women) under HD treatment was studied. The fatty acid composition of their RBCs was analyzed by gas chromatography. During the study period of 5 years, 54 deaths occurred. After adjustment for 10 confounding factors, the Cox hazard ratio of all-cause mortality of the patients on HD in the highest DHA tertile (>8.1%, 15 deaths) was 0.43 (95% CI 0.21-0.88) compared with those patients in the lowest DHA tertile (HD. Copyright © 2010 S. Karger AG, Basel.

Catalytic N{sub 2}O decomposition in a model tail gas from nitric acid plants; Decomposition catalytique du protoxyde d'azote dans un modele de gaz de queue produits par un atelier d'acide nitrique

Energy Technology Data Exchange (ETDEWEB)

Mul, G.; Xu, X.; Perez Ramirez, J.; Vaccaro, A.R.; Kapteijn, F.; Moulijn, J.A. [Delft University of Technology, Faculty of Chemical Technology and Materials Sciences, Delft (Netherlands)

2001-07-01

In this study direct catalytic decomposition of N{sub 2}O in simulated tail-gas from nitric acid plants, containing water, oxygen, NO{sub x}, was investigated. Three groups of catalysts were prepared: oxide-supported catalysts; zeolite-based catalysts; mixed oxides derived from hydrotalcites-like (HTLc) materials. The activity of these types of catalysts was tested in an advanced automated six-flow reactor system. Nobel metal (Ru, Rh) based catalysts, either supported on zeolites or ex-hydrotalcite compositions (Mg-Al or Co-Al mixed oxides), and Fe-ZSM-5 effectively decompose N{sub 2}O in tail-gas conditions at temperatures of about 400-450 deg C, typical for certain nitric acid plants. Catalysts active for tail gas temperatures of 230-250 deg C, typical for other nitric acid plants, were not found. This is mainly due to the dramatic negative effect of especially water and NO{sub x} on the conversion of N{sub 2}O. The negative effect of NO{sub x} observed for many catalysts might be related to the formation of surface nitrites and nitrates, blocking active sites for N{sub 2}O decomposition in the 200-300 deg C temperature range. (authors)

Hydrocarbon fuels from gas phase decarboxylation of hydrolyzed free fatty acid

KAUST Repository

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.

Disposal of hazardous wastes in Canada's Northwest Territories

International Nuclear Information System (INIS)

Henney, P.L.; Heinke, G.W.

1991-01-01

In the past decade, many jurisdictions have attempted to estimate quantities and types of hazardous wastes generated within their boundaries. Similar studies done in the Northwest Territories (NWT) are out-of-date, incomplete or specific to only one type of waste or geographical location. In 1990, an industry, business and community survey was conducted to determine types and quantities of hazardous wastes generated in the NWT and currently used disposal methods for these wastes. The survey revealed that 2,500 tons of hazardous wastes were generated each year, including waste oil and petroleum products, fuel tank sludges, acid batteries, spent solvents, antifreeze an waste paint. In many regions, disposal of these wastes may be routine, but waste disposal in arctic and subarctic regions presents unique difficulties. Severe climate, transportation expense, isolation and small quantities of waste generated can make standard solutions expensive, difficult or impossible to apply. Unique solutions are needed for northern waste disposal. The aim of this paper is to give an overview of low-cost, on-site or local hazardous wastes disposal options which can be applied in Canada's NWT and also in other arctic, remote or less-developed regions

Chemical hazards from acid crater lakes

Science.gov (United States)

van Bergen, M. J.; Sumarti, S.; Heikens, A.; Bogaard, T. A.; Hartiyatun, S.

2003-04-01

Acid crater lakes, which are hosted by a considerable number of active volcanoes, form a potential threat for local ecosystems and human health, as they commonly contain large amounts of dissolved chemicals. Subsurface seepage or overflow can lead to severe deterioration of the water quality of rivers and wells, as observations around several of these volcanoes have shown. The Ijen crater lake in East Java (Indonesia) is a striking example, as this reservoir of hyperacid (pHfluoride-rich water is the source of a ca. 50 km long acid river that transports substantial quantities of potentially toxic elements. A downstream trend of increasing pH from fluoride levels pose some of the most severe environmental threats. Its concentration decreases from ca. 1300 mg/kg in the lake to ca. 10 mg/kg in a coastal area downstream, where virtually all of the river water is used for irrigating rice fields and other cropland. Apart from serious problems for agriculture, our survey of 55 drinking water wells in the irrigation area shows that 50% contain fluoride above the 1.5 ppm WHO limit, in line with the observation that dental fluorosis is widespread among the ca. 100,000 residents of the area. A conspicuous spatial correlation between fluoride concentrations and the irrigation system suggest that long-term (century) infiltration of irrigation water may have affected the quality of groundwater. Fluorosis is also a problem in some villages within the caldera, where well water sources may have a more direct subsurface connection with the lake system. From our observations we conclude that water-quality monitoring is especially needed for health reasons in volcanic areas where volatile elements, derived from passively degassing magma, are intercepted by (sub) surface water bodies.

Biosynthetic Studies of the Male Marking Pheromone in Bumblebees by Using Labelled Fatty Acids and Two-Dimensional Gas Chromatography with Mass Detection

Czech Academy of Sciences Publication Activity Database

Žáček, Petr; Kindl, Jiří; Frišonsová, K.; Průchová, Markéta; Votavová, A.; Hovorka, Oldřich; Kovalczuk, T.; Valterová, Irena

2015-01-01

Roč. 80, č. 5 (2015), s. 839-850 ISSN 2192-6506 Institutional support: RVO:61388963 Keywords : biosynthesis * bumblebees * fatty acids * gas chromatography * pheromones Subject RIV: CC - Organic Chemistry Impact factor: 2.836, year: 2015

Removal of radioactive and other hazardous material from fluid waste

Science.gov (United States)

Tranter, Troy J [Idaho Falls, ID; Knecht, Dieter A [Idaho Falls, ID; Todd, Terry A [Aberdeen, ID; Burchfield, Larry A [W. Richland, WA; Anshits, Alexander G [Krasnoyarsk, RU; Vereshchagina, Tatiana [Krasnoyarsk, RU; Tretyakov, Alexander A [Zheleznogorsk, RU; Aloy, Albert S [St. Petersburg, RU; Sapozhnikova, Natalia V [St. Petersburg, RU

2006-10-03

Hollow glass microspheres obtained from fly ash (cenospheres) are impregnated with extractants/ion-exchangers and used to remove hazardous material from fluid waste. In a preferred embodiment the microsphere material is loaded with ammonium molybdophosphonate (AMP) and used to remove radioactive ions, such as cesium-137, from acidic liquid wastes. In another preferred embodiment, the microsphere material is loaded with octyl(phenyl)-N-N-diisobutyl-carbamoylmethylphosphine oxide (CMPO) and used to remove americium and plutonium from acidic liquid wastes.

Hazard Evaluation for a Salt Well Centrifugal Pump Design Using Service Water for Lubrication and Cooling

International Nuclear Information System (INIS)

GRAMS, W.H.

2000-01-01

This report documents the results of a preliminary hazard analysis (PHA) covering the new salt well pump design. The PHA identified ten hazardous conditions mapped to four analyzed accidents: flammable gas deflagrations, fire in contaminated area, tank failure due to excessive loads, and waste transfer leaks. This document also presents the results of the control decision/allocation process. A backflow preventer and associated limiting condition were assigned

78 FR 34703 - Pipeline Safety: Information Collection Activities, Revision to Gas Distribution Annual Report

Science.gov (United States)

2013-06-10

... DEPARTMENT OF TRANSPORTATION Pipeline and Hazardous Materials Safety Administration [Docket No. PHMSA-2013-0004] Pipeline Safety: Information Collection Activities, Revision to Gas Distribution Annual Report AGENCY: Pipeline and Hazardous Materials Safety Administration, DOT. ACTION: Notice and request...

A new flowsheeting tool for flue gas treating

NARCIS (Netherlands)

van Elk, E. P.; Arendsen, A. R. J.; Versteeg, G. F.

2009-01-01

A new flowsheeting tool, specifically designed for steady-state simulation of acid gas treating processes, has been developed. The models implemented in the new tool combine all issues relevant for the design, optimization and analysis of acid gas treating processes, including post-combustion and

77 FR 34123 - Pipeline Safety: Public Meeting on Integrity Management of Gas Distribution Pipelines

Science.gov (United States)

2012-06-08

... DEPARTMENT OF TRANSPORTATION Pipeline and Hazardous Materials Safety Administration [Docket No. PHMSA-2012-0100] Pipeline Safety: Public Meeting on Integrity Management of Gas Distribution Pipelines AGENCY: Office of Pipeline Safety, Pipeline and Hazardous Materials Safety Administration, DOT. ACTION...

Comparison of two derivatization methods for the analysis of fatty acids and trans fatty acids in bakery products using gas chromatography.

Science.gov (United States)

Salimon, Jumat; Omar, Talal A; Salih, Nadia

2014-01-01

Two different procedures for the methylation of fatty acids (FAs) and trans fatty acids (TFAs) in food fats were compared using gas chromatography (GC-FID). The base-catalyzed followed by an acid-catalyzed method (KOCH3/HCl) and the base-catalyzed followed by (trimethylsilyl)diazomethane (TMS-DM) method were used to prepare FA methyl esters (FAMEs) from lipids extracted from food products. In general, both methods were suitable for the determination of cis/trans FAs. The correlation coefficients (r) between the methods were relatively small (ranging from 0.86 to 0.99) and had a high level of agreement for the most abundant FAs. The significant differences (P = 0.05) can be observed for unsaturated FAs (UFAs), specifically for TFAs. The results from the KOCH3/HCl method showed the lowest recovery values (%R) and higher variation (from 84% to 112%), especially for UFAs. The TMS-DM method had higher R values, less variation (from 90% to 106%), and more balance between variation and %RSD values in intraday and interday measurements (less than 4% and 6%, resp.) than the KOCH3/HCl method, except for C12:0, C14:0, and C18:0. Nevertheless, the KOCH3/HCl method required shorter time and was less expensive than the TMS-DM method which is more convenient for an accurate and thorough analysis of rich cis/trans UFA samples.

Comparison of Two Derivatization Methods for the Analysis of Fatty Acids and Trans Fatty Acids in Bakery Products Using Gas Chromatography

Science.gov (United States)

Salimon, Jumat; Omar, Talal A.; Salih, Nadia

2014-01-01

Two different procedures for the methylation of fatty acids (FAs) and trans fatty acids (TFAs) in food fats were compared using gas chromatography (GC-FID). The base-catalyzed followed by an acid-catalyzed method (KOCH3/HCl) and the base-catalyzed followed by (trimethylsilyl)diazomethane (TMS–DM) method were used to prepare FA methyl esters (FAMEs) from lipids extracted from food products. In general, both methods were suitable for the determination of cis/trans FAs. The correlation coefficients (r) between the methods were relatively small (ranging from 0.86 to 0.99) and had a high level of agreement for the most abundant FAs. The significant differences (P = 0.05) can be observed for unsaturated FAs (UFAs), specifically for TFAs. The results from the KOCH3/HCl method showed the lowest recovery values (%R) and higher variation (from 84% to 112%), especially for UFAs. The TMS-DM method had higher R values, less variation (from 90% to 106%), and more balance between variation and %RSD values in intraday and interday measurements (less than 4% and 6%, resp.) than the KOCH3/HCl method, except for C12:0, C14:0, and C18:0. Nevertheless, the KOCH3/HCl method required shorter time and was less expensive than the TMS-DM method which is more convenient for an accurate and thorough analysis of rich cis/trans UFA samples. PMID:24719581

Comparison of Two Derivatization Methods for the Analysis of Fatty Acids and Trans Fatty Acids in Bakery Products Using Gas Chromatography

Directory of Open Access Journals (Sweden)

Jumat Salimon

2014-01-01

Full Text Available Two different procedures for the methylation of fatty acids (FAs and trans fatty acids (TFAs in food fats were compared using gas chromatography (GC-FID. The base-catalyzed followed by an acid-catalyzed method (KOCH3/HCl and the base-catalyzed followed by (trimethylsilyldiazomethane (TMS–DM method were used to prepare FA methyl esters (FAMEs from lipids extracted from food products. In general, both methods were suitable for the determination of cis/trans FAs. The correlation coefficients (r between the methods were relatively small (ranging from 0.86 to 0.99 and had a high level of agreement for the most abundant FAs. The significant differences (P=0.05 can be observed for unsaturated FAs (UFAs, specifically for TFAs. The results from the KOCH3/HCl method showed the lowest recovery values (%R and higher variation (from 84% to 112%, especially for UFAs. The TMS-DM method had higher R values, less variation (from 90% to 106%, and more balance between variation and %RSD values in intraday and interday measurements (less than 4% and 6%, resp. than the KOCH3/HCl method, except for C12:0, C14:0, and C18:0. Nevertheless, the KOCH3/HCl method required shorter time and was less expensive than the TMS-DM method which is more convenient for an accurate and thorough analysis of rich cis/trans UFA samples.

Hazard interactions and interaction networks (cascades) within multi-hazard methodologies

Science.gov (United States)

Gill, Joel C.; Malamud, Bruce D.

2016-08-01

This paper combines research and commentary to reinforce the importance of integrating hazard interactions and interaction networks (cascades) into multi-hazard methodologies. We present a synthesis of the differences between multi-layer single-hazard approaches and multi-hazard approaches that integrate such interactions. This synthesis suggests that ignoring interactions between important environmental and anthropogenic processes could distort management priorities, increase vulnerability to other spatially relevant hazards or underestimate disaster risk. In this paper we proceed to present an enhanced multi-hazard framework through the following steps: (i) description and definition of three groups (natural hazards, anthropogenic processes and technological hazards/disasters) as relevant components of a multi-hazard environment, (ii) outlining of three types of interaction relationship (triggering, increased probability, and catalysis/impedance), and (iii) assessment of the importance of networks of interactions (cascades) through case study examples (based on the literature, field observations and semi-structured interviews). We further propose two visualisation frameworks to represent these networks of interactions: hazard interaction matrices and hazard/process flow diagrams. Our approach reinforces the importance of integrating interactions between different aspects of the Earth system, together with human activity, into enhanced multi-hazard methodologies. Multi-hazard approaches support the holistic assessment of hazard potential and consequently disaster risk. We conclude by describing three ways by which understanding networks of interactions contributes to the theoretical and practical understanding of hazards, disaster risk reduction and Earth system management. Understanding interactions and interaction networks helps us to better (i) model the observed reality of disaster events, (ii) constrain potential changes in physical and social vulnerability

Minimum detectable gas concentration performance evaluation method for gas leak infrared imaging detection systems.

Science.gov (United States)

Zhang, Xu; Jin, Weiqi; Li, Jiakun; Wang, Xia; Li, Shuo

2017-04-01

Thermal imaging technology is an effective means of detecting hazardous gas leaks. Much attention has been paid to evaluation of the performance of gas leak infrared imaging detection systems due to several potential applications. The minimum resolvable temperature difference (MRTD) and the minimum detectable temperature difference (MDTD) are commonly used as the main indicators of thermal imaging system performance. This paper establishes a minimum detectable gas concentration (MDGC) performance evaluation model based on the definition and derivation of MDTD. We proposed the direct calculation and equivalent calculation method of MDGC based on the MDTD measurement system. We build an experimental MDGC measurement system, which indicates the MDGC model can describe the detection performance of a thermal imaging system to typical gases. The direct calculation, equivalent calculation, and direct measurement results are consistent. The MDGC and the minimum resolvable gas concentration (MRGC) model can effectively describe the performance of "detection" and "spatial detail resolution" of thermal imaging systems to gas leak, respectively, and constitute the main performance indicators of gas leak detection systems.

Gas phase ion chemistry

CERN Document Server

Bowers, Michael T

1979-01-01

Gas Phase Ion Chemistry, Volume 2 covers the advances in gas phase ion chemistry. The book discusses the stabilities of positive ions from equilibrium gas-phase basicity measurements; the experimental methods used to determine molecular electron affinities, specifically photoelectron spectroscopy, photodetachment spectroscopy, charge transfer, and collisional ionization; and the gas-phase acidity scale. The text also describes the basis of the technique of chemical ionization mass spectrometry; the energetics and mechanisms of unimolecular reactions of positive ions; and the photodissociation

External hazards analysis approach to level 1 PSA of Mochovce NPP - Slovakia

International Nuclear Information System (INIS)

Stojka, Tibor

2000-01-01

Analyses of external events had been first time performed at the design stage of the Mochovce NPP showing sufficiently low contribution of external hazards to core damage frequency. But, based on IAEA document 'Safety problems of WWER-440/213 NPPs and the categorization' (IAEA-EBP-WWER-03, 1996), the need of new reassessment arose due to discrepancy of some origin recommendations in compare with present IAEA ones. Mochovce NPP Nuclear Safety Improvements Program elaborated at the same time included the IAEA recommendations and following improvements were proposed to perform in context of external events. 1. Seismic project and new locality seismic evaluation This safety improvement includes also some 'on site' technical improvements in seismic stability of structures and equipment. 2. Unit specific analyses of extreme meteorologic conditions. This safety improvement focuses on impact of feasible extreme conditions on NPP systems caused by rain, snow and hail storms, frost, winds, low and high temperatures. 3. Analyses of external hazards caused by humans. In this safety improvement were specified: feasible sources of explosions; analyses of hydrogen, gas and propane-calor gas depots; air crash risk. The results of these implemented safety improvements were considered in the PSA study. The External hazards analysis is also part of Level 1 PSA Mochovce NPP performed by PSA Department of VUJE Trnava Inc., Engineering, Design and Research Organization, Slovakia. Some partial analyses are performed in cooperation with following companies DS and S - SAIC, USA and Geophysical Institute Academy of Science, Slovakia Relko, Slovakia. Basic documents are: NUREG/CR-2300 'PRA Procedures Guide - A Guide to the Performance of Probabilistic Risk Assessments for Nuclear Power Plants' and IAEA SS No. 50-P-7 'Treatment of External Hazards in PSA for NPPs. The external hazards analysis consists of following parts: 1. Geography and plant locality; 2. Nearby industry; 3. Extreme

78 FR 41496 - Pipeline Safety: Meetings of the Gas and Liquid Pipeline Advisory Committees

Science.gov (United States)

2013-07-10

... DEPARTMENT OF TRANSPORTATION Pipeline and Hazardous Materials Safety Administration [Docket No. PHMSA-2013-0156] Pipeline Safety: Meetings of the Gas and Liquid Pipeline Advisory Committees AGENCY: Pipeline and Hazardous Materials Safety Administration (PHMSA), DOT. ACTION: Notice of advisory committee...

78 FR 33891 - Safety Advisory: Compressed Gas Cylinders That Have Not Been Tested Properly

Science.gov (United States)

2013-06-05

... DEPARTMENT OF TRANSPORTATION Pipeline and Hazardous Materials Safety Administration [Docket No... Properly AGENCY: Pipeline and Hazardous Materials Safety Administration (PHMSA), DOT. ACTION: Safety... otherwise safely discharged. Cylinders that are filled with a material other than an atmospheric gas should...

Waste Issues Associated with the Safe Movement of Hazardous Chemicals

International Nuclear Information System (INIS)

Dare, J. H.; Cournoyer, M. E.

2002-01-01

Moving hazardous chemicals presents the risk of exposure for workers engaged in the activity and others that might be in the immediate area. Adverse affects are specific to the chemicals and can range from minor skin, eye, or mucous membrane irritation, to burns, respiratory distress, nervous system dysfunction, or even death. A case study is presented where in the interest of waste minimization; original shipping packaging was removed from a glass bottle of nitric acid, while moving corrosive liquid through a security protocol into a Radiological Control Area (RCA). During the transfer, the glass bottle broke. The resulting release of nitric acid possibly exposed 12 employees with one employee being admitted overnight at a hospital for observation. This is a clear example of administrative controls to reduce the generation of suspect radioactive waste being implemented at the expense of employee health. As a result of this event, material handling procedures that assure the safe movement of hazardous chemicals through a security protocol into a radiological control area were developed. Specifically, hazardous material must be transferred using original shipping containers and packaging. While this represents the potential to increase the generation of suspect radioactive waste in a radiological controlled area, arguments are presented that justify this change. Security protocols for accidental releases are also discussed. In summary, the 12th rule of ''Green Chemistry'' (Inherently Safer Chemistry for Accident Prevention) should be followed: the form of a substance used in a chemical process (Movement of Hazardous Chemicals) should be chosen to minimize the potential for chemical accidents, including releases

Waste Issues Associated with the Safe Movement of Hazardous Chemicals

Energy Technology Data Exchange (ETDEWEB)

Dare, J. H.; Cournoyer, M. E.

2002-02-26

Moving hazardous chemicals presents the risk of exposure for workers engaged in the activity and others that might be in the immediate area. Adverse affects are specific to the chemicals and can range from minor skin, eye, or mucous membrane irritation, to burns, respiratory distress, nervous system dysfunction, or even death. A case study is presented where in the interest of waste minimization; original shipping packaging was removed from a glass bottle of nitric acid, while moving corrosive liquid through a security protocol into a Radiological Control Area (RCA). During the transfer, the glass bottle broke. The resulting release of nitric acid possibly exposed 12 employees with one employee being admitted overnight at a hospital for observation. This is a clear example of administrative controls to reduce the generation of suspect radioactive waste being implemented at the expense of employee health. As a result of this event, material handling procedures that assure the safe movement of hazardous chemicals through a security protocol into a radiological control area were developed. Specifically, hazardous material must be transferred using original shipping containers and packaging. While this represents the potential to increase the generation of suspect radioactive waste in a radiological controlled area, arguments are presented that justify this change. Security protocols for accidental releases are also discussed. In summary, the 12th rule of ''Green Chemistry'' (Inherently Safer Chemistry for Accident Prevention) should be followed: the form of a substance used in a chemical process (Movement of Hazardous Chemicals) should be chosen to minimize the potential for chemical accidents, including releases.

Organic acids in naturally colored surface waters

Science.gov (United States)

Lamar, William L.; Goerlitz, D.F.

1966-01-01

Most of the organic matter in naturally colored surface waters consists of a mixture of carboxylic acids or salts of these acids. Many of the acids color the water yellow to brown; however, not all of the acids are colored. These acids range from simple to complex, but predominantly they are nonvolatile polymeric carboxylic acids. The organic acids were recovered from the water by two techniques: continuous liquid-liquid extraction with n-butanol and vacuum evaporation at 50?C (centigrade). The isolated acids were studied by techniques of gas, paper, and column chromatography and infrared spectroscopy. About 10 percent of the acids recovered were volatile or could be made volatile for gas chromatographic analysis. Approximately 30 of these carboxylic acids were isolated, and 13 of them were individually identified. The predominant part of the total acids could not be made volatile for gas chromatographic analysis. Infrared examination of many column chromatographic fractions indicated that these nonvolatile substances are primarily polymeric hydroxy carboxylic acids having aromatic and olefinic unsaturation. The evidence suggests that some of these acids result from polymerization in aqueous solution. Elemental analysis of the sodium fusion products disclosed the absence of nitrogen, sulfur, and halogens.

Incorporation of oxygen into abscisic acid and phaseic acid for molecular oxygen

International Nuclear Information System (INIS)

Creelman, R.A.; Zeevaart, J.A.D.

1984-01-01

Abscisic acid accumulates in detached, wilted leaves of Xanthium strumariu. When these leaves are subsequently rehydrated, phaseic acid, a catabolite of abscisic acid, accumulates. Analysis by gas chromatography-mass spectrometry of phaseic acid isolated from stressed and subsequently rehydrated leaves placed in an atmosphere containing 20% 18 O 2 and 80% N 2 indicates that one atom of 18 O is incorporated in the 6'-hydroxymethyl group of phaseic acid. This suggests that the enzyme that converts abscisic acid to phaseic acid is an oxygenase. Analysis by gas chromatography-mass spectrometry of abscisic acid isolated from stressed leaves kept in an atmosphere containing 18 O 2 indicates that one atom of 18 O is presented in the carboxyl group of abscisic acid. Thus, when abscisic acid accumulates in water-streesed leaves, only one of the four oxygens present in the abscisic acid molecule is derived from molecular oxygen. This suggest that either (a) the oxygen present in the 1'-, 4'-, and one of the two oxygens at the 1-position of abscisic acid arise from water, or (b) there exists a stored precursor with oxygen atoms already present in the 1'- and 4'-positions of abscisic acid which is converted to abscisic acid under conditions of water stress. 17 references, 2 figures, 1 tables

Incorporation of oxygen into abscisic Acid and phaseic Acid from molecular oxygen.

Science.gov (United States)

Creelman, R A; Zeevaart, J A

1984-05-01

Abscisic acid accumulates in detached, wilted leaves of Xanthium strumarium. When these leaves are subsequently rehydrated, phaseic acid, a catabolite of abscisic acid, accumulates. Analysis by gas chromatography-mass spectrometry of phaseic acid isolated from stressed and subsequently rehydrated leaves placed in an atmosphere containing 20% (18)O(2) and 80% N(2) indicates that one atom of (18)O is incorporated in the 6'-hydroxymethyl group of phaseic acid. This suggests that the enzyme that converts abscisic acid to phaseic acid is an oxygenase.Analysis by gas chromatography-mass spectrometry of abscisic acid isolated from stressed leaves kept in an atmosphere containing (18)O(2) indicates that one atom of (18)O is present in the carboxyl group of abscisic acid. Thus, when abscisic acid accumulates in water-stressed leaves, only one of the four oxygens present in the abscisic acid molecule is derived from molecular oxygen. This suggests that either (a) the oxygen present in the 1'-, 4'-, and one of the two oxygens at the 1-position of abscisic acid arise from water, or (b) there exists a stored precursor with oxygen atoms already present in the 1'- and 4'-positions of abscisic acid which is converted to abscisic acid under conditions of water stress.

[Gas chromatography in quantitative analysis of hydrocyanic acid and its salts in cadaveric blood].

Science.gov (United States)

Iablochkin, V D

2003-01-01

A direct gas chromatography method was designed for the quantitative determination of cyanides (prussic acid) in cadaveric blood. Its sensitivity is 0.05 mg/ml. The routine volatile products, including substances, which emerge due to putrefaction of organic matters, do not affect the accuracy and reproducibility of the method; the exception is H-propanol that was used as the internal standard. The method was used in legal chemical expertise related with acute cyanide poisoning (suicide) as well as with poisoning of products of combustion of nonmetals (foam-rubber). The absolute error does not exceed 10% with a mean quadratic deviation of 0.0029-0.0033 mg.

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

Energy Technology Data Exchange (ETDEWEB)

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)

Volcanic Gas

Science.gov (United States)

... offensive odor. It is sometimes referred to as sewer gas. Interestingly, the human nose is more sensitive ... the atmosphere where they can potentially cause acid rain. In an ash -producing eruption, ash particles are ...

Risk management technique for liquefied natural gas facilities

Science.gov (United States)

Fedor, O. H.; Parsons, W. N.

1975-01-01

Checklists have been compiled for planning, design, construction, startup and debugging, and operation of liquefied natural gas facilities. Lists include references to pertinent safety regulations. Methods described are applicable to handling of other hazardous materials.

Multi-gas interaction modeling on decorated semiconductor interfaces: A novel Fermi distribution-based response isotherm and the inverse hard/soft acid/base concept

Science.gov (United States)

Laminack, William; Gole, James

2015-12-01

A unique MEMS/NEMS approach is presented for the modeling of a detection platform for mixed gas interactions. Mixed gas analytes interact with nanostructured decorating metal oxide island sites supported on a microporous silicon substrate. The Inverse Hard/Soft acid/base (IHSAB) concept is used to assess a diversity of conductometric responses for mixed gas interactions as a function of these nanostructured metal oxides. The analyte conductometric responses are well represented using a combination diffusion/absorption-based model for multi-gas interactions where a newly developed response absorption isotherm, based on the Fermi distribution function is applied. A further coupling of this model with the IHSAB concept describes the considerations in modeling of multi-gas mixed analyte-interface, and analyte-analyte interactions. Taking into account the molecular electronic interaction of both the analytes with each other and an extrinsic semiconductor interface we demonstrate how the presence of one gas can enhance or diminish the reversible interaction of a second gas with the extrinsic semiconductor interface. These concepts demonstrate important considerations in the array-based formats for multi-gas sensing and its applications.

Advanced Acid Gas Separation Technology for Clean Power and Syngas Applications

Energy Technology Data Exchange (ETDEWEB)

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.

Gas chromatography/isotope ratio mass spectrometry: analysis of methanol, ethanol and acetic acid by direct injection of aqueous alcoholic and acetic acid samples.

Science.gov (United States)

Ai, Guomin; Sun, Tong; Dong, Xiuzhu

2014-08-15

Methanol, ethanol, and acetic acid are not easily extracted from aqueous samples and are susceptible to isotope fractionation in gas chromatography/isotope ratio mass spectrometry (GC/IRMS) analysis. Developing a direct dilution GC/IRMS method for aqueous samples, by adjusting the sample concentrations in common solvents to be similar to each other and using a fixed GC split ratio, is very convenient and important because any linearity effects caused by amount-dependent isotope fractionation can be avoided. The suitability of acetonitrile and acetone solvents for the GC/IRMS analysis of pure methanol, ethanol and acetic acid, and commercial liquor and vinegar samples was evaluated using n-hexane and water as control solvents. All the solvents including water were separated from the analyte on a HP-INNOWAX column and were diverted away from the combustion interface. The influence of liquor matrix on the ethanol GC/IRMS analyses was evaluated by adding pure ethanol to liquor samples. Acetonitrile and acetone gave similar δ(13) C values for pure ethanol and pure acetic acid to those obtained in water and n-hexane, and also gave similar δ(13) C values of ethanol in liquor and acetic acid in white vinegar to that obtained in water. For methanol analysis, acetonitrile and refined acetone gave similar δ(13) C values to that obtained in water, but n-hexane was not a suitable solvent. In addition, isotopic fractionation caused by solvent and solute interactions was observed. We recommend using acetonitrile for the GC/IRMS analysis of aqueous alcoholic samples, and acetone for the analysis of aqueous acetic acid samples. This direct dilution method can provide high accurate and precise GC/IRMS analysis of the relative changes in δ(13) C values of methanol, ethanol, and acetic acid. Copyright © 2014 John Wiley & Sons, Ltd.

Surface acidity scales: Experimental measurements of Brønsted acidities on anatase TiO2 and comparison with coinage metal surfaces

Science.gov (United States)

Silbaugh, Trent L.; Boaventura, Jaime S.; Barteau, Mark A.

2016-08-01

The first quantitative surface acidity scale for Brønsted acids on a solid surface is presented through the use of titration-displacement and equilibrium experiments on anatase TiO2. Surface acidities of species on TiO2 correlated with gas phase acidities, as was previously observed in qualitative studies of Brønsted acid displacement on Ag(110), Cu(110) and Au(111). A 90% compression of the surface acidity scale relative to the gas phase was observed due to compensation from the covalent component of the conjugate base - surface bond. Adsorbed conjugate bases need not be completely anionic for correlations with gas phase acidities to hold. Positive and negative substituent effects, such as substituted fluorine and hydrocarbon sidechain dispersion interactions with the surface, may modify the surface acidity scale, in agreement with previous experimental and theoretical work on Au(111).

Shale Gas Exploration and Exploitation Induced Risks - SHEER

Science.gov (United States)

Capuano, Paolo; Orlecka-Sikora, Beata; Lasocki, Stanislaw; Cesca, Simone; Gunning, Andrew; jaroslawsky, Janusz; Garcia-Aristizabal, Alexander; Westwood, Rachel; Gasparini, Paolo

2017-04-01

Shale gas operations may affect the quality of air, water and landscapes; furthermore, it can induce seismic activity, with the possible impacts on the surrounding infrastructure. The SHEER project aims at setting up a probabilistic methodology to assess and mitigate the short and the long term environmental risks connected to the exploration and exploitation of shale gas. In particular we are investigating risks associated with groundwater contamination, air pollution and induced seismicity. A shale gas test site located in Poland (Wysin) has been monitored before, during and after the fracking operations with the aim of assessing environmental risks connected with groundwater contamination, air pollution and earthquakes induced by fracking and injection of waste water. The severity of each of these hazards depends strongly on the unexpected enhanced permeability pattern, which may develop as an unwanted by-product of the fracking processes and may become pathway for gas and fluid migration towards underground water reservoirs or the surface. The project is devoted to monitor and understand how far this enhanced permeability pattern develops both in space and time. The considered hazards may be at least partially inter-related as they all depend on this enhanced permeability pattern. Therefore they are being approached from a multi-hazard, multi parameter perspective. We expect to develop methodologies and procedures to track and model fracture evolution around shale gas exploitation sites and a robust statistically based, multi-parameter methodology to assess environmental impacts and risks across the operational lifecycle of shale gas. The developed methodologies are going to be applied and tested on a comprehensive database consisting of seismicity, changes of the quality of ground-waters and air, ground deformations, and operational data collected from the ongoing monitoring episode (Wysin) and past episodes: Lubocino (Poland), Preese Hall (UK), Oklahoma (USA

Apparatus for incinerating hazardous waste

Science.gov (United States)

Chang, R.C.W.

1994-12-20

An apparatus is described for incinerating wastes, including an incinerator having a combustion chamber, a fluid-tight shell enclosing the combustion chamber, an afterburner, an off-gas particulate removal system and an emergency off-gas cooling system. The region between the inner surface of the shell and the outer surface of the combustion chamber forms a cavity. Air is supplied to the cavity and heated as it passes over the outer surface of the combustion chamber. Heated air is drawn from the cavity and mixed with fuel for input into the combustion chamber. The pressure in the cavity is maintained at least approximately 2.5 cm WC higher than the pressure in the combustion chamber. Gases cannot leak from the combustion chamber since the pressure outside the chamber (inside the cavity) is higher than the pressure inside the chamber. The apparatus can be used to treat any combustible wastes, including biological wastes, toxic materials, low level radioactive wastes, and mixed hazardous and low level transuranic wastes. 1 figure.

Electrochemical treatment of mixed and hazardous waste

International Nuclear Information System (INIS)

Dziewinski, J.; Marczak, S.; Smith, W.; Nuttall, E.

1995-01-01

Los Alamos National Laboratory (LANL) and The University of New Mexico are jointly developing an electrochemical process for treating hazardous and radioactive wastes. The wastes treatable by the process include toxic metal solutions, cyanide solutions, and various organic wastes that may contain chlorinated organic compounds. The main component of the process is a stack of electrolytic cells with peripheral equipment such as a rectifier, feed system, tanks with feed and treated solutions, and a gas-venting system. During the treatment, toxic metals are deposited on the cathode, cyanides are oxidized on the anode, and organic compounds are anodically oxidized by direct or mediated electrooxidation, depending on their type. Bench scale experimental studies have confirmed the feasibility of applying electrochemical systems to processing of a great variety of hazardous and mixed wastes. The operating parameters have been defined for different waste compositions using surrogate wastes. Mixed wastes are currently treated at bench scale as part of the treatability study

utilization of adsorption and/or liquid membranes techniques in treatment of some hazardous substances

International Nuclear Information System (INIS)

Hussin, L.M.S.

2011-01-01

environmental pollution, as a consequence of the industrialization process, is one of the major problems that has to be solved and controlled. The most important treatment processes for metals and dyes contaminated waste streams include chemical precipitation, membrane, filtration, ion exchange, carbon adsorption and coprecipitation/adsorption. However, all these techniques have their inherent advantages and limitations in applications. These processes usually need expensive facility and high maintenance cost. Therefore, there is a need for more economical alternative technologies for the treatment of metals and dyes contaminated waste streams. The aim of present work is to study the treatment of some hazardous substances such as heavy metals e.g. ( lead, cobalt and strontium) and dyes e.g. ( acid red 73, and acid blue 74 ) using either adsorption or liquid emulsion membrane techniques. The experimental part deals with the application of adsorption and liquid emulsion membrane techniques for removal of some hazardous substances such as metal ions ( lead, cobalt and strontium) and dyes (acid red 73 and acid blue 74). All the apparatus and techniques employed were described.

Flammable gas safety program

International Nuclear Information System (INIS)

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

1994-01-01

This report describes the status of developing analytical methods to account for the organic constituents in Hanford waste tanks, with particular emphasis on those tanks that have been assigned to the Flammable Gas Watch List. Six samples of core segments from Tank 101-SY, obtained during the window E core sampling, have been analyzed for organic constituents. Four of the samples were from the upper region, or convective layer, of the tank and two were from the lower, nonconvective layer. The samples were analyzed for chelators, chelator fragments, and several carboxylic acids by derivatization gas chromatography/mass spectrometry (GC/MS). The major components detected were ethylenediaminetetraacetic acid (EDTA), nitroso-iminodiacetic acid (NIDA), nitrilotriacetic acid (NTA), citric acid (CA), succinic acid (SA), and ethylenediaminetriacetic acid (ED3A). The chelator of highest concentration was EDTA in all six samples analyzed. Liquid chromatography (LC) was used to quantitate low molecular weight acids (LMWA) 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 (TOC) in the samples analyzed was accounted for by these acids. Oxalate constituted approximately 40% of the TOC in the nonconvective layer samples. Oxalate was found to be approximately 3 to 4 times higher in concentration in the nonconvective layer than in the convective layer. During FY 1993, LC methods for analyzing LWMA, and two chelators N-(2-hydroxyethyl) ethylenediaminetriacetic acid and EDTA, were transferred to personnel in the Analytical Chemistry Laboratory and the 222-S laboratory

Mapping the conformational free energy of aspartic acid in the gas phase and in aqueous solution.

Science.gov (United States)

Comitani, Federico; Rossi, Kevin; Ceriotti, Michele; Sanz, M Eugenia; Molteni, Carla

2017-04-14

The conformational free energy landscape of aspartic acid, a proteogenic amino acid involved in a wide variety of biological functions, was investigated as an example of the complexity that multiple rotatable bonds produce even in relatively simple molecules. To efficiently explore such a landscape, this molecule was studied in the neutral and zwitterionic forms, in the gas phase and in water solution, by means of molecular dynamics and the enhanced sampling method metadynamics with classical force-fields. Multi-dimensional free energy landscapes were reduced to bi-dimensional maps through the non-linear dimensionality reduction algorithm sketch-map to identify the energetically stable conformers and their interconnection paths. Quantum chemical calculations were then performed on the minimum free energy structures. Our procedure returned the low energy conformations observed experimentally in the gas phase with rotational spectroscopy [M. E. Sanz et al., Phys. Chem. Chem. Phys. 12, 3573 (2010)]. Moreover, it provided information on higher energy conformers not accessible to experiments and on the conformers in water. The comparison between different force-fields and quantum chemical data highlighted the importance of the underlying potential energy surface to accurately capture energy rankings. The combination of force-field based metadynamics, sketch-map analysis, and quantum chemical calculations was able to produce an exhaustive conformational exploration in a range of significant free energies that complements the experimental data. Similar protocols can be applied to larger peptides with complex conformational landscapes and would greatly benefit from the next generation of accurate force-fields.

Mapping the conformational free energy of aspartic acid in the gas phase and in aqueous solution

Science.gov (United States)

Comitani, Federico; Rossi, Kevin; Ceriotti, Michele; Sanz, M. Eugenia; Molteni, Carla

2017-04-01

The conformational free energy landscape of aspartic acid, a proteogenic amino acid involved in a wide variety of biological functions, was investigated as an example of the complexity that multiple rotatable bonds produce even in relatively simple molecules. To efficiently explore such a landscape, this molecule was studied in the neutral and zwitterionic forms, in the gas phase and in water solution, by means of molecular dynamics and the enhanced sampling method metadynamics with classical force-fields. Multi-dimensional free energy landscapes were reduced to bi-dimensional maps through the non-linear dimensionality reduction algorithm sketch-map to identify the energetically stable conformers and their interconnection paths. Quantum chemical calculations were then performed on the minimum free energy structures. Our procedure returned the low energy conformations observed experimentally in the gas phase with rotational spectroscopy [M. E. Sanz et al., Phys. Chem. Chem. Phys. 12, 3573 (2010)]. Moreover, it provided information on higher energy conformers not accessible to experiments and on the conformers in water. The comparison between different force-fields and quantum chemical data highlighted the importance of the underlying potential energy surface to accurately capture energy rankings. The combination of force-field based metadynamics, sketch-map analysis, and quantum chemical calculations was able to produce an exhaustive conformational exploration in a range of significant free energies that complements the experimental data. Similar protocols can be applied to larger peptides with complex conformational landscapes and would greatly benefit from the next generation of accurate force-fields.

Volcanic hazards to airports

Science.gov (United States)

Guffanti, M.; Mayberry, G.C.; Casadevall, T.J.; Wunderman, R.

2009-01-01

Volcanic activity has caused significant hazards to numerous airports worldwide, with local to far-ranging effects on travelers and commerce. Analysis of a new compilation of incidents of airports impacted by volcanic activity from 1944 through 2006 reveals that, at a minimum, 101 airports in 28 countries were affected on 171 occasions by eruptions at 46 volcanoes. Since 1980, five airports per year on average have been affected by volcanic activity, which indicates that volcanic hazards to airports are not rare on a worldwide basis. The main hazard to airports is ashfall, with accumulations of only a few millimeters sufficient to force temporary closures of some airports. A substantial portion of incidents has been caused by ash in airspace in the vicinity of airports, without accumulation of ash on the ground. On a few occasions, airports have been impacted by hazards other than ash (pyroclastic flow, lava flow, gas emission, and phreatic explosion). Several airports have been affected repeatedly by volcanic hazards. Four airports have been affected the most often and likely will continue to be among the most vulnerable owing to continued nearby volcanic activity: Fontanarossa International Airport in Catania, Italy; Ted Stevens Anchorage International Airport in Alaska, USA; Mariscal Sucre International Airport in Quito, Ecuador; and Tokua Airport in Kokopo, Papua New Guinea. The USA has the most airports affected by volcanic activity (17) on the most occasions (33) and hosts the second highest number of volcanoes that have caused the disruptions (5, after Indonesia with 7). One-fifth of the affected airports are within 30 km of the source volcanoes, approximately half are located within 150 km of the source volcanoes, and about three-quarters are within 300 km; nearly one-fifth are located more than 500 km away from the source volcanoes. The volcanoes that have caused the most impacts are Soufriere Hills on the island of Montserrat in the British West Indies

Quantitative physical models of volcanic phenomena for hazards assessment of critical infrastructures

Science.gov (United States)

Costa, Antonio

2016-04-01

Volcanic hazards may have destructive effects on economy, transport, and natural environments at both local and regional scale. Hazardous phenomena include pyroclastic density currents, tephra fall, gas emissions, lava flows, debris flows and avalanches, and lahars. Volcanic hazards assessment is based on available information to characterize potential volcanic sources in the region of interest and to determine whether specific volcanic phenomena might reach a given site. Volcanic hazards assessment is focussed on estimating the distances that volcanic phenomena could travel from potential sources and their intensity at the considered site. Epistemic and aleatory uncertainties strongly affect the resulting hazards assessment. Within the context of critical infrastructures, volcanic eruptions are rare natural events that can create severe hazards. In addition to being rare events, evidence of many past volcanic eruptions is poorly preserved in the geologic record. The models used for describing the impact of volcanic phenomena generally represent a range of model complexities, from simplified physics based conceptual models to highly coupled thermo fluid dynamical approaches. Modelling approaches represent a hierarchy of complexity, which reflects increasing requirements for well characterized data in order to produce a broader range of output information. In selecting models for the hazard analysis related to a specific phenomenon, questions that need to be answered by the models must be carefully considered. Independently of the model, the final hazards assessment strongly depends on input derived from detailed volcanological investigations, such as mapping and stratigraphic correlations. For each phenomenon, an overview of currently available approaches for the evaluation of future hazards will be presented with the aim to provide a foundation for future work in developing an international consensus on volcanic hazards assessment methods.

Environmental hazards for pipelines in coastal regions/shore approaches

International Nuclear Information System (INIS)

Jinsi, B.K.

1995-01-01

Often oil/gas and other hydrocarbons discovered and produced offshore are transported to onshore facilities via submarine pipelines. The route of such pipelines traverses through coastal/shore approach regions. For a rational/economic design, safe installation and subsequent operation it is of utmost importance to review, evaluate and finalize various environmental hazard such as winds, waves, currents, seabed topography, seabed and sub-bottom soils, seabed erosion and soil accretion. This paper addresses the above described environmental hazards, their assessment and techniques to prepare design parameters which must be used for stability analysis, installation methods, long term operation and maintenance for the shore approaches. Additionally, various proven pipeline installation and stabilization techniques for the shore approach region are detailed. As case histories, three approaches installed in the Dutch North Sea are described

Hazardous air pollutants; Yugai taiki osen busshitsu

Energy Technology Data Exchange (ETDEWEB)

Ogata, A

2000-02-14

Hazardous air pollutants (HAPs) are chemical substances listed up since those have a fear of increasing carcinogenic danger even in a small quantity by a long-term exposure. In Europe and Japan, approximately 200 names of substances are known. Concretely, they are particulate substnaces such as floating dusts, gaseous inorganics such as fluorine compound and chroline gas, volatile organic compounds (VOCs). Among those, especially, 22 substances are cited as those that Japan tackles in priority. HAPs explained in this paper mean mostly VOCs such as benzene, tetrachloroethylene and trichloroethylene among those. (NEDO)

Incorporation of Oxygen into Abscisic Acid and Phaseic Acid from Molecular Oxygen 1

Science.gov (United States)

Creelman, Robert A.; Zeevaart, Jan A. D.

1984-01-01

Abscisic acid accumulates in detached, wilted leaves of Xanthium strumarium. When these leaves are subsequently rehydrated, phaseic acid, a catabolite of abscisic acid, accumulates. Analysis by gas chromatography-mass spectrometry of phaseic acid isolated from stressed and subsequently rehydrated leaves placed in an atmosphere containing 20% 18O2 and 80% N2 indicates that one atom of 18O is incorporated in the 6′-hydroxymethyl group of phaseic acid. This suggests that the enzyme that converts abscisic acid to phaseic acid is an oxygenase. Analysis by gas chromatography-mass spectrometry of abscisic acid isolated from stressed leaves kept in an atmosphere containing 18O2 indicates that one atom of 18O is present in the carboxyl group of abscisic acid. Thus, when abscisic acid accumulates in water-stressed leaves, only one of the four oxygens present in the abscisic acid molecule is derived from molecular oxygen. This suggests that either (a) the oxygen present in the 1′-, 4′-, and one of the two oxygens at the 1-position of abscisic acid arise from water, or (b) there exists a stored precursor with oxygen atoms already present in the 1′- and 4′-positions of abscisic acid which is converted to abscisic acid under conditions of water stress. PMID:16663564

Potential for a hazardous geospheric response to projected future climate changes.

Science.gov (United States)

McGuire, B

2010-05-28

Periods of exceptional climate change in Earth history are associated with a dynamic response from the geosphere, involving enhanced levels of potentially hazardous geological and geomorphological activity. The response is expressed through the adjustment, modulation or triggering of a broad range of surface and crustal phenomena, including volcanic and seismic activity, submarine and subaerial landslides, tsunamis and landslide 'splash' waves, glacial outburst and rock-dam failure floods, debris flows and gas-hydrate destabilization. In relation to anthropogenic climate change, modelling studies and projection of current trends point towards increased risk in relation to a spectrum of geological and geomorphological hazards in a warmer world, while observations suggest that the ongoing rise in global average temperatures may already be eliciting a hazardous response from the geosphere. Here, the potential influences of anthropogenic warming are reviewed in relation to an array of geological and geomorphological hazards across a range of environmental settings. A programme of focused research is advocated in order to: (i) understand better those mechanisms by which contemporary climate change may drive hazardous geological and geomorphological activity; (ii) delineate those parts of the world that are most susceptible; and (iii) provide a more robust appreciation of potential impacts for society and infrastructure.

Heavy Metals and Radioactivity Reduction from Acid Mine Drainage Lime Neutralized Sludge

Science.gov (United States)

Mashifana, T.; Sithole, N.

2018-03-01

The worldwide known treatment processes of acid mine drainage result into the formation of hydrous ferric oxides that is amorphous, poorly crystalline and into the generation of hazardous voluminous sludge posing threat to the environment. Applicable treatment technologies to treat hazardous solid material and produce useful products are limited and in most cases nonexistence. A chemical treatment process utilizing different reagents was developed to treat hazardous acid mine drainage (AMD) sludge with the objectives to conduct radioactivity assessment of the sludge generated from lime treatment process and determine the reagent that provides the best results. Leaching with 0.5 M citric acid, 0.4 M oxalic acid, 0.5 M sodium carbonate and 0.5 M sodium bicarbonate was investigated. The leaching time applied was 24 hours at 25 °C. The characterization of the raw AMD revealed that the AMD sludge from lime treatment process is radioactive. The sludge was laden with radioactive elements namely, 238U, 214Pb, 226Ra, 232Th, 40K and 214Bi. 0.5 M citric acid provided the best results and the hazardous contaminants were significantly reduced. The constituents in the sludge after treatment revealed that there is a great potential for the sludge to be used for other applications such as building and construction.

No reduction using sublimination of cyanuric acid

Science.gov (United States)

Perry, Robert A.

1996-01-01

A method of reducing the NO content of a gas stream comprises contacting the gas stream with an amount of HNCO at a temperature effective for heat-induced decomposition of cyanuric acid, said amount and temperature being effective for the resultant lowering of the NO content of the gas stream, said cyanuric acid being particulate and having a particle size of less than 90 .mu.m.

77 FR 22387 - Pipeline Safety: Information Collection Activities, Revision to Gas Transmission and Gathering...

Science.gov (United States)

2012-04-13

... DEPARTMENT OF TRANSPORTATION Pipeline and Hazardous Materials Safety Administration [Docket No. PHMSA-2012-0024] Pipeline Safety: Information Collection Activities, Revision to Gas Transmission and Gathering Pipeline Systems Annual Report, Gas Transmission and Gathering Pipeline Systems Incident Report...

77 FR 58616 - Pipeline Safety: Information Collection Activities, Revision to Gas Transmission and Gathering...

Science.gov (United States)

2012-09-21

... DEPARTMENT OF TRANSPORTATION Pipeline and Hazardous Materials Safety Administration [Docket No. PHMSA-2012-0024] Pipeline Safety: Information Collection Activities, Revision to Gas Transmission and Gathering Pipeline Systems Annual Report, Gas Transmission and Gathering Pipeline Systems Incident Report...

FY 1998 annual report on the preliminary research and development of techniques for developing resources from gas-hydrate. Studies on gas-hydrate exploration, excavation techniques, methods for assessing environmental impacts, and gas hydrate handling systems; 1998 nendo gas hydrate shigenka gijutsu sendoken kaihatsu seika hokokusho. Tansanado ni kansuru kenkyu kaihatsu, kussaku gijutsu nado ni kansuru kenkyu kaihatsu, kankyo eikyo hyokaho no kenkyu kaihatsu, riyo system ni kansuru chosa kenkyu

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-03-01

This R and D project is for the preliminary studies on development of the following 4 types of techniques for developing resources from gas-hydrates (GH): (1) gas-hydrate exploration, (2) excavation techniques, (3) methods for assessing environmental impacts, and (4) gas hydrate handling systems. The FY 1988 R and D results are described. For gas-hydrate exploration, the methods for analyzing inorganic ions and trace quantities of elements, which are necessary for accurately estimating the offshore GH around Japan, are established; and case studies are conducted for methods of predicting GH deposit forming mechanisms, and stability fields of GH, based on terrestrial heat flow and seismic data. For excavation techniques, GH decomposition rate is analyzed using a laboratory system which reproduces conditions of excavation of GH layers. For methods for assessing environmental impacts, a geo-hazard predicting model is established, to study ground displacement and gas leakage sensing systems and data transmission systems to cope with the hazards. For gas hydrate handling systems, an overall system is studied, and storage and transportation systems are outlined. (NEDO)

Exhaust gas treatment by electron beam irradiation

International Nuclear Information System (INIS)

Shibamura, Yokichi; Suda, Shoichi; Kobayashi, Toshiki

1991-01-01

Among global environmental problems, atmospheric pollution has been discussed since relatively old days, and various countermeasures have been taken, but recently in connection with acid rain, the efficient and economical treatment technology is demanded. As the denitration and desulfurization technology for the exhaust gas from the combustion of fossil fuel, the incineration of city trash and internal combustion engines, three is the treatment method by electron beam irradiation. By irradiating electron beam to exhaust gas, nitrogen oxides and sulfur oxides are oxidized to nitric acid and sulfuric acid, and by promoting the neutralization of these acids with injected alkali, harmless salts are recovered. This method has the merit that nitrogen oxides and surfur oxides can be removed efficiently with a single system. In this report, as for the exhaust gas treatment by electron beam irradiation, its principle, features, and the present status of research and development are described, and in particular, the research on the recent exhaust gas treatment in city trash incineration is introduced. This treatment method is a dry process, accordingly, waste water disposal is unnecessary. The reaction products are utilized as fertilizer, and waste is not produced. (K.I.)

Effects of xylazine on acid-base balance and arterial blood-gas tensions in goats under different environmental temperature and humidity conditions

Directory of Open Access Journals (Sweden)

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.

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

Science.gov (United States)

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. Copyright © 2012 Elsevier Ltd. All rights reserved.

Measurements to determine the sulfuric acid dew point and the SO sub 3 concentration in flue gas of power plant vessels. Messungen zur Bestimmung des Saeuretaupunktes und der SO sub 3 -Konzentration im Rauchgas von Kraftwerkskesseln

Energy Technology Data Exchange (ETDEWEB)

Derichs, W.; Menden, W. (RWE Energie AG, Bergheim (Germany)); Ebel, P.K. (Apparatebau Hundsbach GmbH, Baden-Baden (Germany))

1990-01-01

Among the customary methods of dew point determination, the technique of recording the increase in conductivity between two electrodes at the moment of acid condensing onto them, and measuring at the same time the temperature of the sensor, is appropriate to determine the sulfuric acid dew point in dust-laden flue gas. By means of the sensitivity of a newly developed sensor, the accuracy of the measurement method could be improved to such an extent that also low acid dew points and rapid changes can be recorded reliably. Measurements have shown that the acid dew point primarily depends on the SO{sub 3} content which is substantially determined by the sulfur content of the fuel and the type of flue gas ducts. Further influential quantities include flue gas humidity, air surplus, other gaseous flue gas components such as HCl and HF, as well as the quantity, composition and temperature-dependent adsorption capability of the flue dusts. (orig./BBR).

Volcanic hazards of the Idaho National Engineering Laboratory and adjacent areas

International Nuclear Information System (INIS)

Hackett, W.R.; Smith, R.P.

1994-12-01

Potential volcanic hazards are assessed, and hazard zone maps are developed for the Idaho National Engineering Laboratory (INEL) and adjacent areas. The basis of the hazards assessment and mapping is the past volcanic history of the INEL region, and the apparent similarity of INEL volcanism with equivalent, well-studied phenomena in other regions of active volcanism, particularly Hawaii and Iceland. The most significant hazards to INEL facilities are associated with basaltic volcanism, chiefly lava flows, which move slowly and mainly threaten property by inundation or burning. Related hazards are volcanic gases and tephra, and ground disturbance associated with the ascent of magma under the volcanic zones. Several volcanic zones are identified in the INEL area. These zones contain most of the volcanic vents and fissures of the region and are inferred to be the most probable sites of future INEL volcanism. Volcanic-recurrence estimates are given for each of the volcanic zones based on geochronology of the lavas, together with the results of field and petrographic investigations concerning the cogenetic relationships of INEL volcanic deposits and associated magma intrusion. Annual probabilities of basaltic volcanism within the INEL volcanic zones range from 6.2 x 10 -5 per year (average 16,000-year interval between eruptions) for the axial volcanic zone near the southern INEL boundary and the Arco volcanic-rift zone near the western INEL boundary, to 1 x 10 -5 per year (average 100,000-year interval between eruptions) for the Howe-East Butte volcanic rift zone, a geologically old and poorly defined feature of the central portion of INEL. Three volcanic hazard zone maps are developed for the INEL area: lava flow hazard zones, a tephra (volcanic ash) and gas hazard zone, and a ground-deformation hazard zone. The maps are useful in land-use planning, site selection, and safety analysis

Advanced On Board Inert Gas Generation System (OBBIGS), Phase II

Data.gov (United States)

National Aeronautics and Space Administration — Valcor Engineering Corporation proposes to develop an advanced On Board Inert Gas Generation System, OBIGGS, for aircraft fuel tank inerting to prevent hazardous...

Prediction and control of rock burst of coal seam contacting gas in deep mining

Energy Technology Data Exchange (ETDEWEB)

En-yuan Wang; Xiao-fei Liu; En-lai Zhao; Zhen-tang Liu [China University of Mining and Technology, Xuzhou (China). School of Safety Engineering

2009-06-15

By analyzing the characteristics and the production mechanism of rock burst that goes with abnormal gas emission in deep coal seams, the essential method of eliminating abnormal gas emission by eliminating the occurrence of rock burst or depressing the magnitude of rock burst was considered. The No.237 working face in Nanshan coal mine was selected as the typical working face contacting gas in deep mining; aimed at this working face, a system of rock burst prediction and control for coal seam contacting gas in deep mining was established using the three-dimensional distinct element code software 3DEC. This system includes three parts: (1) regional prediction of rock burst hazard before mining; (2) local prediction of rock burst hazard during mining; and (3) rock burts control by an electromagnetic radiation method and specific drilling method. 8 refs., 4 figs., 1 tab.

Substitution of Linoleic Acid for Other Macronutrients and the Risk of Ischemic Stroke.

Science.gov (United States)

Venø, Stine K; Schmidt, Erik B; Jakobsen, Marianne U; Lundbye-Christensen, Søren; Bach, Flemming W; Overvad, Kim

2017-12-01

Ischemic stroke is a major health problem worldwide, but the influence of dietary factors on stroke risk is not well known. This study aimed to investigate the risk of ischemic stroke and its subtypes with a higher intake from linoleic acid and a concomitant lower intake from saturated fatty acids, monounsaturated fatty acids, or glycemic carbohydrates. In the Danish prospective Diet, Cancer, and Health Study of 57 053 participants aged 50 to 64 years at baseline, information on diet was collected using a validated semiquantitative food frequency questionnaire. Information on ischemic stroke was obtained from the Danish National Patient Register, and cases were all validated and subclassified according to the TOAST (Trial of ORG 10172 in Acute Stroke Treatment) classification. Substitution of linoleic acid for saturated fatty acid, monounsaturated fatty acid, or glycemic carbohydrates was investigated in relation to the risk of ischemic stroke and subtypes. Cox proportional hazards regression was used to estimate the associations with ischemic stroke adjusting for appropriate confounders. During 13.5 years of follow-up 1879 participants developed ischemic stroke. A slightly lower risk of ischemic stroke was found with a 5% higher intake of linoleic acid and a concomitant lower intake of saturated fatty acid (hazard ratio, 0.98; 95% confidence interval, 0.83-1.16), monounsaturated fatty acid (hazard ratio, 0.80; 95% confidence interval, 0.63-1.02), and glycemic carbohydrates (hazard ratio, 0.92; 95% confidence interval, 0.78-1.09), although not statistically significant. Similar patterns of association were found for large-artery atherosclerosis and small-vessel occlusions. This study suggests that replacing saturated fatty acid, glycemic carbohydrate, or monounsaturated fatty acid with linoleic acid may be associated with a lower risk of ischemic stroke. © 2017 American Heart Association, Inc.

System of treating flue gas

International Nuclear Information System (INIS)

Ziegler, D.L.

1975-01-01

A system is described for treating or cleaning incinerator flue gas containing acid gases and radioactive and fissionable contaminants. Flue gas and a quench solution are fed into a venturi and then tangentially into the lower portion of a receptacle for restricting volumetric content of the solution. The upper portion of the receptacle contains a scrub bed to further treat or clean the flue gas

NO reduction using sublimation of cyanuric acid

Science.gov (United States)

Perry, R.A.

1996-05-21

A method of reducing the NO content of a gas stream comprises contacting the gas stream with an amount of HNCO at a temperature effective for heat-induced decomposition of cyanuric acid, said amount and temperature being effective for the resultant lowering of the NO content of the gas stream, said cyanuric acid being particulate and having a particle size of less than 90 {micro}m. 1 fig.

Chromatographic efficiency of polar capillary columns applied for the analysis of fatty acid methyl esters by gas chromatography.

Science.gov (United States)

Waktola, Habtewold D; Mjøs, Svein A

2018-04-01

The chromatographic efficiency that could be achieved in temperature-programmed gas chromatography was compared for four capillary columns that are typically applied for analysis of fatty acid methyl esters (FAME). Three different carrier gases, hydrogen, helium and nitrogen, were applied. For each experiment, the carrier gas velocities and the temperature rates were varied with a full 9 × 3 design, with nine levels on the carrier gas velocity and temperature rates of 1, 2 or 3°C/min. Response surface methodology was used to create models of chromatographic efficiency as a function of temperature rate and carrier gas velocity. The chromatographic efficiency was defined as the inverse of peak widths measured in retention index units. The final results were standardized so that the efficiencies that could be achieved within a certain time frame, defined by the retention time of the last compound in the chromatogram, could be compared. The results show that there were clear differences in the efficiencies that could be achieved with the different columns and that the efficiency decreased with increasing polarity of the stationary phase. The differences can be explained by higher resistance to mass transfer in the stationary phase in the most polar columns. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Earth Girl Volcano: An Interactive Casual Game about Complex Volcanic Hazards

Science.gov (United States)

Kerlow, I.

2017-12-01

Earth Girl Volcano is an interactive casual strategy game for disaster preparedness. The project is designed for mainstream audiences, particularly for children, as an engaging and fun way to learn about volcano hazards, monitoring, and mitigation strategies. The game is deceptively simple but it provides a toolbox to address practically all volcanic hazards ranging from gas and ash fall to pyroclastic flows, lava and lahars. This presentation shows the basic dynamic to explore the area, assess the risk, choose the best-suited tools and execute a mitigation strategy within the available budget. This game is a real-time simulation of a crowd evacuation that allows players to intervene before and during the disaster.

A comparison of regional and global catastrophic hazards associated with energy technologies

International Nuclear Information System (INIS)

Heising, C.D.; Inhaber, H.

1983-01-01

This paper reviews some of what is known about the relative catastrophic hazards, on both a regional and global level, of energy technologies, and proposes a logical framework for their comparison. A review of the Inhaber study results is made indicating the relative position of overall nuclear power related risks. Then, concentration is placed on describing the catastrophic and global hazards of energy technologies. Regionally catastrophic hazards include sabotage and other malicious human activities, in addition to severe accidents caused inadvertantly by man, such as fires, reactor core damage events, chemical and poisonous gas releases, fuel storage fires and explosions, in addition to others. Global risks include such hazards as nuclear proliferation, CO 2 , build-up, oil shortages and possible national conflicts over dwindling energy fuels. The conclusion is drawn that consideration of both regional and global catastrophic risks must be made in making energy decisions, and that further study is necessary to better quantify and compare these risks. A simple decision analytic framework for making energy decisions inclusive of catastrophic risk is proposed

Analysis of Chlorine Gas Incident Simulation and Dispersion Within a Complex and Populated Urban Area Via Computation Fluid Dynamics

Directory of Open Access Journals (Sweden)

Eslam Kashi

2015-04-01

Full Text Available In some instances, it is inevitable that large amounts of potentially hazardous chemicals like chlorine gas are stored and used in facilities in densely populated areas. In such cases, all safety issues must be carefully considered. To reach this goal, it is important to have accurate information concerning chlorine gas behaviors and how it is dispersed in dense urban areas. Furthermore, maintaining adequate air movement and the ability to purge ambient from potential toxic and dangerous chemicals like chlorine gas could be helpful. These are among the most important actions to be taken toward the improvement of safety in a big metropolis like Tehran. This paper investigates and analyzes chlorine gas leakage scenarios, including its dispersion and natural air ventilation  effects on how it might be geographically spread in a city, using computational  fluid dynamic (CFD. Simulations of possible hazardous events and solutions for preventing or reducing their probability are presented to gain a better insight into the incidents. These investigations are done by considering hypothetical scenarios which consist of chlorine gas leakages from pipelines or storage tanks under different conditions. These CFD simulation results are used to investigate and analyze chlorine gas behaviors, dispersion, distribution, accumulation, and other possible hazards by means of a simplified CAD model of an urban area near a water-treatment facility. Possible hazards as well as some prevention and post incident solutions are also suggested.

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

Data.gov (United States)

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...

Occupational health hazards in veterinary medicine: physical, psychological, and chemical hazards.

Science.gov (United States)

Epp, Tasha; Waldner, Cheryl

2012-02-01

This paper reports physical, psychological, and chemical hazards relevant to western Canadian veterinarians as obtained by a self-administered mailed questionnaire. Nine-three percent (750/806) of veterinarians reported some form of injury during the previous 5 years; 17% of respondents (131/791) indicated injuries that resulted in 1 or more days off work. Median stress levels were similar across work environments; overall, 7% (57/813) indicated either no stress or severe stress, while 53% (428/813) indicated moderate stress. Twenty percent (3/15) of food animal practitioners and 37% (114/308) of companion animal practitioners who took X-rays reported accidental exposure. Accidental exposure to gas anesthetic was reported by 69% (394/570) of those in private practice. Exposure to chemicals occurred in all work environments. Veterinarians in western Canada are at risk of minor to severe injury due to both animal and non-animal related causes.

Hazards and hazard combinations relevant for the safety of nuclear power plants

Science.gov (United States)

Decker, Kurt; Brinkman, Hans; Raimond, Emmanuel

2017-04-01

The potential of the contemporaneous impact of different, yet causally related, hazardous events and event cascades on nuclear power plants is a major contributor to the overall risk of nuclear installations. In the aftermath of the Fukushima accident, which was caused by a combination of severe ground shaking by an earthquake, an earthquake-triggered tsunami and the disruption of the plants from the electrical grid by a seismically induced landslide, hazard combinations and hazard cascades moved into the focus of nuclear safety research. We therefore developed an exhaustive list of external hazards and hazard combinations which pose potential threats to nuclear installations in the framework of the European project ASAMPSAE (Advanced Safety Assessment: Extended PSA). The project gathers 31 partners from Europe, North Amerika and Japan. The list comprises of exhaustive lists of natural hazards, external man-made hazards, and a cross-correlation matrix of these hazards. The hazard list is regarded comprehensive by including all types of hazards that were previously cited in documents by IAEA, the Western European Nuclear Regulators Association (WENRA), and others. 73 natural hazards and 24 man-made external hazards are included. Natural hazards are grouped into seismotectonic hazards, flooding and hydrological hazards, extreme values of meteorological phenomena, rare meteorological phenomena, biological hazards / infestation, geological hazards, and forest fire / wild fire. The list of external man-made hazards includes industry accidents, military accidents, transportation accidents, pipeline accidents and other man-made external events. The large number of different hazards results in the extremely large number of 5.151 theoretically possible hazard combinations (not considering hazard cascades). In principle all of these combinations are possible to occur by random coincidence except for 82 hazard combinations that - depending on the time scale - are mutually

Geochemical modeling of magmatic gas scrubbing

Directory of Open Access Journals (Sweden)

B. Gambardella

2005-06-01

Full Text Available The EQ3/6 software package, version 7.2 was successfully used to model scrubbing of magmatic gas by pure water at 0.1 MPa, in the liquid and liquid-plus-gas regions. Some post-calculations were necessary to account for gas separation effects. In these post-calculations, redox potential was considered to be fixed by precipitation of crystalline a-sulfur, a ubiquitous and precocious process. As geochemical modeling is constrained by conservation of enthalpy upon water-gas mixing, the enthalpies of the gas species of interest were reviewed, adopting as reference state the liquid phase at the triple point. Our results confirm that significant emissions of highly acidic gas species (SO2(g, HCl(g, and HF(g are prevented by scrubbing, until dry conditions are established, at least locally. Nevertheless important outgassing of HCl(g can take place from acid, HCl-rich brines. Moreover, these findings support the rule of thumb which is generally used to distinguish SO2-, HCl-, and HF-bearing magmatic gases from SO2-, HCl-, and HF-free hydrothermal gases.

Overlapping Patterns of Rapid Evolution in the Nucleic Acid Sensors cGAS and OAS1 Suggest a Common Mechanism of Pathogen Antagonism and Escape.

Science.gov (United States)

Hancks, Dustin C; Hartley, Melissa K; Hagan, Celia; Clark, Nathan L; Elde, Nels C

2015-05-01

A diverse subset of pattern recognition receptors (PRRs) detects pathogen-associated nucleic acids to initiate crucial innate immune responses in host organisms. Reflecting their importance for host defense, pathogens encode various countermeasures to evade or inhibit these immune effectors. PRRs directly engaged by pathogen inhibitors often evolve under recurrent bouts of positive selection that have been described as molecular 'arms races.' Cyclic GMP-AMP synthase (cGAS) was recently identified as a key PRR. Upon binding cytoplasmic double-stranded DNA (dsDNA) from various viruses, cGAS generates the small nucleotide secondary messenger cGAMP to signal activation of innate defenses. Here we report an evolutionary history of cGAS with recurrent positive selection in the primate lineage. Recent studies indicate a high degree of structural similarity between cGAS and 2'-5'-oligoadenylate synthase 1 (OAS1), a PRR that detects double-stranded RNA (dsRNA), despite low sequence identity between the respective genes. We present comprehensive comparative evolutionary analysis of cGAS and OAS1 primate sequences and observe positive selection at nucleic acid binding interfaces and distributed throughout both genes. Our data revealed homologous regions with strong signatures of positive selection, suggesting common mechanisms employed by unknown pathogen encoded inhibitors and similar modes of evasion from antagonism. Our analysis of cGAS diversification also identified alternately spliced forms missing multiple sites under positive selection. Further analysis of selection on the OAS family in primates, which comprises OAS1, OAS2, OAS3 and OASL, suggests a hypothesis where gene duplications and domain fusion events result in paralogs that provide another means of escaping pathogen inhibitors. Together our comparative evolutionary analysis of cGAS and OAS provides new insights into distinct mechanisms by which key molecular sentinels of the innate immune system have adapted

Overlapping Patterns of Rapid Evolution in the Nucleic Acid Sensors cGAS and OAS1 Suggest a Common Mechanism of Pathogen Antagonism and Escape.

Directory of Open Access Journals (Sweden)

Dustin C Hancks

2015-05-01

Full Text Available A diverse subset of pattern recognition receptors (PRRs detects pathogen-associated nucleic acids to initiate crucial innate immune responses in host organisms. Reflecting their importance for host defense, pathogens encode various countermeasures to evade or inhibit these immune effectors. PRRs directly engaged by pathogen inhibitors often evolve under recurrent bouts of positive selection that have been described as molecular 'arms races.' Cyclic GMP-AMP synthase (cGAS was recently identified as a key PRR. Upon binding cytoplasmic double-stranded DNA (dsDNA from various viruses, cGAS generates the small nucleotide secondary messenger cGAMP to signal activation of innate defenses. Here we report an evolutionary history of cGAS with recurrent positive selection in the primate lineage. Recent studies indicate a high degree of structural similarity between cGAS and 2'-5'-oligoadenylate synthase 1 (OAS1, a PRR that detects double-stranded RNA (dsRNA, despite low sequence identity between the respective genes. We present comprehensive comparative evolutionary analysis of cGAS and OAS1 primate sequences and observe positive selection at nucleic acid binding interfaces and distributed throughout both genes. Our data revealed homologous regions with strong signatures of positive selection, suggesting common mechanisms employed by unknown pathogen encoded inhibitors and similar modes of evasion from antagonism. Our analysis of cGAS diversification also identified alternately spliced forms missing multiple sites under positive selection. Further analysis of selection on the OAS family in primates, which comprises OAS1, OAS2, OAS3 and OASL, suggests a hypothesis where gene duplications and domain fusion events result in paralogs that provide another means of escaping pathogen inhibitors. Together our comparative evolutionary analysis of cGAS and OAS provides new insights into distinct mechanisms by which key molecular sentinels of the innate immune system

Hazardous Waste

Science.gov (United States)

... chemicals can still harm human health and the environment. When you throw these substances away, they become hazardous waste. Some hazardous wastes come from products in our homes. Our garbage can include such hazardous wastes as old batteries, bug spray cans and paint thinner. U.S. residents ...

Acidities of Water and Methanol in Aqueous Solution and DMSO

Science.gov (United States)

Gao, Daqing

2009-01-01

The relative acidities of water and methanol have been a nagging issue. In gas phase, methanol is more acidic than water by 36.0 kJ/mol; however, in aqueous solution, the acidities of methanol and water are almost identical. The acidity of an acid in solution is determined by both the intrinsic gas-phase ionization Gibbs energy and the solvent…

Synthesis and adsorption behaviour of some organic and inorganic sorbents for some hazardous toxic elements

International Nuclear Information System (INIS)

El-Naggar, I.M.; Abou-Mesalam, M.M.; Abdel-Hamid, M.M.; Shady, S.A.; Aly, H.F.

2000-01-01