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1

A Drude polarizable model for liquid hydrogen sulfide.  

PubMed

A polarizable force field for liquid hydrogen sulfide (H2S) has been developed based on the Drude oscillator model. This force field has been designed to be analogous to the SWM4-NDP water model; the model is rigid with point charges assigned to the H and S atoms and a lone pair on the bisector of ?HSH in the molecular plane. Positions of the lone pair and the charges have been defined such that the model has a static dipole moment of 0.98 D, equal to the experimental value. Polarizability is incorporated by a charged (Drude) particle attached to the S atom through a harmonic potential. Intermolecular nonbonded forces are included by use of a Lennard-Jones potential between S atoms. The model was parametrized to reproduce the density, enthalpy of vaporization, and dielectric constant of pure H2S at 212 K and 1 atm. The calculated density, enthalpy of vaporization, shear viscosity coefficient, and self-diffusion coefficient are in good agreement with experiment over the temperature range 212-298 K along the liquid-vapor coexistence curve of liquid H2S. The radial distribution function calculated from this model is in good agreement with experimental diffraction data and ab initio molecular dynamics simulations. PMID:23566029

Riahi, Saleh; Rowley, Christopher N

2013-04-18

2

Reactive iron oxide agents for scavenging hydrogen sulfide from hydrocarbon liquids  

SciTech Connect

Iron oxide particles composed of a crystalline phase of Fe/sub 2/O/sub 3/, Fe/sub 3/O/sub 4/ and combinations thereof together with an amorphous Fe/sub 2/O/sub 3/ moiety or portion and having a surface area of at least 3.5 m/sup 2//g are useful for scavenging hydrogen sulfide from substantially anhydrous non-aqueous liquids, particularly substantially anhydrous hydrocarbon liquids, for example, kerosene.

Fox, I.

1982-08-17

3

Electrochemical Disposal of Hydrogen Sulfide. Final Report, August 31, 1977-September 30, 1982.  

National Technical Information Service (NTIS)

The electrolysis of hydrogen sulfide to elemental hydrogen and sulfur was investigated as a means for hydrogen sulfide disposal. Both the electrolysis of liquid hydrogen sulfide and the electrolysis of aqueous hydrogen sulfide solutions were investigated....

J. C. Angus U. Landau D. L. Feke T. D. Gregory P. M. Kehr

1982-01-01

4

Geothermal hydrogen sulfide removal  

SciTech Connect

UOP Sulfox technology successfully removed 500 ppM hydrogen sulfide from simulated mixed phase geothermal waters. The Sulfox process involves air oxidation of hydrogen sulfide using a fixed catalyst bed. The catalyst activity remained stable throughout the life of the program. The product stream composition was selected by controlling pH; low pH favored elemental sulfur, while high pH favored water soluble sulfate and thiosulfate. Operation with liquid water present assured full catalytic activity. Dissolved salts reduced catalyst activity somewhat. Application of Sulfox technology to geothermal waters resulted in a straightforward process. There were no requirements for auxiliary processes such as a chemical plant. Application of the process to various types of geothermal waters is discussed and plans for a field test pilot plant and a schedule for commercialization are outlined.

Urban, P.

1981-04-01

5

Conversion of Hydrogen Sulfide in Coal Gases to Liquid Elemental Sulfur with Monolithic Catalysts  

SciTech Connect

Removal of hydrogen sulfide (H{sub 2}S) from coal gasifier gas and sulfur recovery are key steps in the development of Department of Energy's (DOE's) advanced power plants that produce electric power and clean transportation fuels with coal and natural gas. These plants will require highly clean coal gas with H{sub 2}S below 1 ppmv and negligible amounts of trace contaminants such as hydrogen chloride, ammonia, alkali, heavy metals, and particulate. The conventional method of sulfur removal and recovery employing amine, Claus, and tail-gas treatment is very expensive. A second generation approach developed under DOE's sponsorship employs hot-gas desulfurization (HGD) using regenerable metal oxide sorbents followed by Direct Sulfur Recovery Process (DSRP). However, this process sequence does not remove trace contaminants and is targeted primarily towards the development of advanced integrated gasification combined cycle (IGCC) plants that produce electricity (not both electricity and transportation fuels). There is an immediate as well as long-term need for the development of cleanup processes that produce highly clean coal gas for next generation power plants. To this end, a novel process is now under development at several research organizations in which the H{sub 2} in coal gas is directly oxidized to elemental sulfur over a selective catalyst. Such a process is ideally suited for coal gas from commercial gasifiers with a quench system to remove essentially all the trace contaminants except H{sub 2}S In the Single-Step Sulfur Recovery Process (SSRP), the direct oxidation of H{sub 2}S to elemental sulfur in the presence of SO{sub 2} is ideally suited for coal gas from commercial gasifiers with a quench system to remove essentially all the trace contaminants except H{sub 2}S. This direct oxidation process has the potential to produce a super clean coal gas more economically than both conventional amine-based processes and HGD/DSRP. The H{sub 2} and CO components of syngas appear to behave as inert with respect to sulfur formed at the SSRP conditions. One problem in the SSRP process that needs to be eliminated or minimized is COS formation that may occur due to reaction of CO with sulfur formed from the Claus reaction. The objectives of this research are to formulate monolithic catalysts for removal of H{sub 2}S from coal gases and minimum formation of COS with monolithic catalyst supports, {gamma}-alumina wash or carbon coats, and catalytic metals, to develop a catalytic regeneration method for a deactivated monolithic catalyst, to measure kinetics of both direct oxidation of H{sub 2}S to elemental sulfur with SO{sub 2} as an oxidizer and formation of COS in the presence of a simulated coal gas mixture containing H{sub 2}, CO, CO{sub 2}, and moisture, using a monolithic catalyst reactor, and to develop kinetic rate equations and model the direct oxidation process to assist in the design of large-scale plants. This heterogeneous catalytic reaction has gaseous reactants such as H{sub 2}S and SO{sub 2}. However, this heterogeneous catalytic reaction has heterogeneous products such as liquid elemental sulfur and steam. To achieve the above-mentioned objectives using a monolithic catalyst reactor, experiments on conversion of hydrogen sulfide into elemental sulfur and formation of COS were carried out for the space time range of 40-560 seconds at 120-150 C to evaluate effects of reaction temperatures, total pressure, space time, and catalyst regeneration on conversion of hydrogen sulfide into elemental sulfur and formation of COS. Simulated coal gas mixtures consist of 3,600-4,000-ppmv hydrogen sulfide, 1,800-2,000 ppmv sulfur dioxide, 23-27 v% hydrogen, 36-41 v% CO, 10-12 v% CO{sub 2}, 0-10 vol % moisture, and nitrogen as remainder. Volumetric feed rates of a simulated coal gas mixture to the reactor are 30-180 SCCM. The temperature of the reactor is controlled in an oven at 120-150 C. The pressure of the reactor is maintained at 40-210 psia. The molar ratio of H{sub 2}S to SO{sub 2} in the monolithic catalyst reactor is mai

K. C. Kwon

2006-09-30

6

Conversion of Hydrogen Sulfide in Coal Gases to Liquid Elemental Sulfur with Monolithic Catalysts  

SciTech Connect

Removal of hydrogen sulfide (H{sub 2}S) from coal gasifier gas and sulfur recovery are key steps in the development of Department of Energy's (DOE's) advanced power plants that produce electric power and clean transportation fuels with coal and natural gas. These plants will require highly clean coal gas with H{sub 2}S below 1 ppmv and negligible amounts of trace contaminants such as hydrogen chloride, ammonia, alkali, heavy metals, and particulate. The conventional method of sulfur removal and recovery employing amine, Claus, and tail-gas treatment is very expensive. A second generation approach developed under DOE's sponsorship employs hot-gas desulfurization (HGD) using regenerable metal oxide sorbents followed by Direct Sulfur Recovery Process (DSRP). However, this process sequence does not remove trace contaminants and is targeted primarily towards the development of advanced integrated gasification combined cycle (IGCC) plants that produce electricity (not both electricity and transportation fuels). There is an immediate as well as long-term need for the development of cleanup processes that produce highly clean coal gas for next generation power plants. To this end, a novel process is now under development at several research organizations in which the H{sub 2}S in coal gas is directly oxidized to elemental sulfur over a selective catalyst. Such a process is ideally suited for coal gas from commercial gasifiers with a quench system to remove essentially all the trace contaminants except H{sub 2}S In the Single-Step Sulfur Recovery Process (SSRP), the direct oxidation of H{sub 2}S to elemental sulfur in the presence of SO{sub 2} is ideally suited for coal gas from commercial gasifiers with a quench system to remove essentially all the trace contaminants except H{sub 2}S. This direct oxidation process has the potential to produce a super clean coal gas more economically than both conventional amine-based processes and HGD/DSRP. The H{sub 2} and CO components of syngas appear to behave as inert with respect to sulfur formed at the SSRP conditions. One problem in the SSRP process that needs to be eliminated or minimized is COS formation that may occur due to reaction of CO with sulfur formed from the Claus reaction. The objectives of this research are to formulate monolithic catalysts for removal of H{sub 2}S from coal gases and minimum formation of COS with monolithic catalyst supports, {gamma}-alumina wash coat, and catalytic metals, to develop a regeneration method for a deactivated monolithic catalyst, to measure kinetics of both direct oxidation of H{sub 2}S to elemental sulfur with SO{sub 2} as an oxidizer and formation of COS in the presence of a simulated coal gas mixture containing H{sub 2}, CO, CO{sub 2}, and moisture, using a monolithic catalyst reactor. The task of developing kinetic rate equations and modeling the direct oxidation process to assist in the design of large-scale plants will be abandoned since formulation of catalysts suitable for the removal of H{sub 2}S and COS is being in progress. This heterogeneous catalytic reaction has gaseous reactants such as H{sub 2}S and SO{sub 2}. However, this heterogeneous catalytic reaction has heterogeneous products such as liquid elemental sulfur and steam. Experiments on conversion of hydrogen sulfide into elemental sulfur and formation of COS were carried out for the space time range of 46-570 seconds under reaction conditions to formulate catalysts suitable for the removal of H{sub 2}S and COS from coal gases and evaluate their capabilities in reducing hydrogen sulfide and COS in coal gases. Simulated coal gas mixtures consist of 3,200-4,000-ppmv hydrogen sulfide, 1,600-20,000-ppmv sulfur dioxide, 18-27 v% hydrogen, 29-41 v% CO, 8-12 v% CO{sub 2}, 0-10 vol % moisture, and nitrogen as remainder. Volumetric feed rates of simulated coal gas mixtures to the reactor are 30 - 180 cm{sup 3}/min at 1 atm and 25 C (SCCM). The temperature of the reactor is controlled in an oven at 120-155 C. The pressure of the reactor is maintained at 40-210 psia. The molar ratio

K.C. Kwon

2009-09-30

7

Suicide with hydrogen sulfide.  

PubMed

This presentation will address the recent rise of suicide deaths resulting from the asphyxiation by hydrogen sulfide (H2S) gas.Hydrogen sulfide poisoning has been an infrequently encountered cause of death in medical examiner practice. Most H2S deaths that have been reported occurred in association with industrial exposure.More recently, H2S has been seen in the commission of suicide, particularly in Japan. Scattered reports of this phenomenon have also appeared in the United States.We have recently observed 2 intentional asphyxial deaths in association with H2S. In both cases, the decedents committed suicide in their automobiles. They generated H2S by combining a sulfide-containing tree spray with toilet bowl cleaner (with an active ingredient of hydrogen chloride acid). Both death scenes prompted hazardous materials team responses because of notes attached to the victims' car windows indicating the presence of toxic gas. Autopsy findings included discoloration of lividity and an accentuation of the gray matter of the brain. Toxicology testing confirmed H2S exposure with the demonstration of high levels of thiosulfate in blood.In summary, suicide with H2S appears to be increasing in the United States. PMID:23574866

Sams, Ralph Newton; Carver, H Wayne; Catanese, Charles; Gilson, Thomas

2013-06-01

8

30 CFR 250.808 - Hydrogen sulfide.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Hydrogen sulfide. 250.808 Section 250...Safety Systems § 250.808 Hydrogen sulfide. Production operations in zones known to contain hydrogen sulfide (H2 S) or in zones...

2013-07-01

9

Fatality Assessment and Control Evaluation (FACE) for Michigan: Two Individuals Overcome By Hydrogen Sulfide Gas While Cleaning a Farm Facility Water Well with 28% Liquid Muriatic Acid.  

National Technical Information Service (NTIS)

On August 15, 2001, two males, an Amish farmer, 42 years old, and a friend, 60 years old, died from inhalation of hydrogen sulfide gas while cleaning the well screen of a driven point well with 28% uninhibited liquid muriatic acid. The well was approximat...

2002-01-01

10

Inhaled Hydrogen Sulfide  

PubMed Central

Background Breathing hydrogen sulfide (H2S) has been reported to induce a suspended animation–like state with hypothermia and a concomitant metabolic reduction in rodents. However, the impact of H2S breathing on cardiovascular function remains incompletely understood. In this study, the authors investigated the cardiovascular and metabolic effects of inhaled H2S in a murine model. Methods The impact of breathing H2S on cardiovascular function was examined using telemetry and echocardiography in awake mice. The effects of breathing H2S on carbon dioxide production and oxygen consumption were measured at room temperature and in a warmed environment. Results Breathing H2S at 80 parts per million by volume at 27°C ambient temperature for 6 h markedly reduced heart rate, core body temperature, respiratory rate, and physical activity, whereas blood pressure remained unchanged. Echocardiography demonstrated that H2S exposure decreased both heart rate and cardiac output but preserved stroke volume. Breathing H2S for 6 h at 35°C ambient temperature (to prevent hypothermia) decreased heart rate, physical activity, respiratory rate, and cardiac output without altering stroke volume or body temperature. H2S breathing seems to induce bradycardia by depressing sinus node activity. Breathing H2S for 30 min decreased whole body oxygen consumption and carbon dioxide production at either 27° or 35°C ambient temperature. Both parameters returned to baseline levels within 10 min after the cessation of H2S breathing. Conclusions Inhalation of H2S at either 27° or 35°C reversibly depresses cardiovascular function without changing blood pressure in mice. Breathing H2S also induces a rapidly reversible reduction of metabolic rate at either body temperature.

Volpato, Gian Paolo; Searles, Robert; Yu, Binglan; Scherrer-Crosbie, Marielle; Bloch, Kenneth D.; Ichinose, Fumito; Zapol, Warren M.

2010-01-01

11

Thermochemical method for producing hydrogen from hydrogen sulfide  

SciTech Connect

Hydrogen is produced from hydrogen sulfide by a 3-step, thermochemical process comprising: (a) contacting hydrogen sulfide with carbon dioxide to form carbonyl sulfide and water, (b) contacting the carbonyl sulfide produced in (a) with oxygen to form carbon monoxide and sulfur dioxide, and (c) contacting the carbon monoxide produced in (b) with water to form carbon dioxide and hydrogen.

Herrington, D.R.

1984-02-21

12

30 CFR 250.808 - Hydrogen sulfide.  

Code of Federal Regulations, 2010 CFR

...SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Production Safety Systems § 250.808 Hydrogen sulfide. Production operations in zones known to contain hydrogen sulfide (H2 S) or in zones where the presence of H2...

2010-07-01

13

30 CFR 250.807 - Hydrogen sulfide.  

Code of Federal Regulations, 2010 CFR

...SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Production Safety Systems § 250.807 Hydrogen sulfide. Production operations in zones known to contain hydrogen sulfide (H2 S) or in zones where the presence of H2...

2009-07-01

14

30 CFR 250.504 - Hydrogen sulfide.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Hydrogen sulfide. 250.504 Section 250...Well-Completion Operations § 250.504 Hydrogen sulfide. When a well-completion...conducted in zones known to contain hydrogen sulfide (H2 S) or in zones...

2013-07-01

15

30 CFR 250.604 - Hydrogen sulfide.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Hydrogen sulfide. 250.604 Section 250...Well-Workover Operations § 250.604 Hydrogen sulfide. When a well-workover...conducted in zones known to contain hydrogen sulfide (H2 S) or in zones...

2013-07-01

16

30 CFR 250.604 - Hydrogen sulfide.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Hydrogen sulfide. 250.604 Section 250...Well-Workover Operations § 250.604 Hydrogen sulfide. When a well-workover...conducted in zones known to contain hydrogen sulfide (H2 S) or in zones...

2010-07-01

17

30 CFR 250.604 - Hydrogen sulfide.  

Code of Federal Regulations, 2010 CFR

...2009-07-01 2009-07-01 false Hydrogen sulfide. 250.604 Section 250...Well-Workover Operations § 250.604 Hydrogen sulfide. When a well-workover...conducted in zones known to contain hydrogen sulfide (H2 S) or in zones...

2009-07-01

18

Endogenous production of hydrogen sulfide in mammals  

Microsoft Academic Search

Summary. Hydrogen sulfide is one of three gases involved in biological functions and synthesized in vivo. Like NO and CO, it seems to act as a neuromodulator: it modulates NMDA glutamate receptor function. CBS seems to be the only source of hydrogen sulfide in the brain, whereas the liver synthesizes hydrogen sulfide via cystathionase. In the heart, the third pathway

P. Kamoun

2004-01-01

19

30 CFR 250.504 - Hydrogen sulfide.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Hydrogen sulfide. 250.504 Section 250...Well-Completion Operations § 250.504 Hydrogen sulfide. When a well-completion...conducted in zones known to contain hydrogen sulfide (H2 S) or in zones...

2010-07-01

20

30 CFR 250.504 - Hydrogen sulfide.  

Code of Federal Regulations, 2010 CFR

...2009-07-01 2009-07-01 false Hydrogen sulfide. 250.504 Section 250...Well-Completion Operations § 250.504 Hydrogen sulfide. When a well-completion...conducted in zones known to contain hydrogen sulfide (H2 S) or in zones...

2009-07-01

21

Removal of hydrogen sulfide and carbonyl sulfide from gas-streams  

SciTech Connect

Hydrogen sulfide and carbonyl sulfide are removed from a gas stream in a staged procedure characterized by conversion of the hydrogen sulfide to produce sulfur in aqueous solution, hydrolysis of the carbonyl sulfide remaining in the gas stream to produce hydrogen sulfide and carbon dioxide, and removal of the hydrogen sulfide from the gas stream.

Deal, C.H.; Lieder, C.A.

1982-06-01

22

Hydrogen sulfide as a neuromodulator  

Microsoft Academic Search

Hydrogen sulfide (H2S) is a well-known toxic gas with the smell of rotten eggs. Since the first description of the toxicity of H2S in 1713, most studies about H2S have been devoted to its toxic effects. Recently, H2S has been proposed as a physiologically active messenger. Three groups discovered that the brain contains relatively high\\u000a concentrations of endogenous H2S. This

Hideo Kimura

2002-01-01

23

Hydrogen sulfide: Neurochemistry and neurobiology  

Microsoft Academic Search

Current evidence suggests that hydrogen sulfide (H2S) plays an important role in brain functions, probably acting as a neuromodulator as well as an intracellular messenger. In the mammalian CNS, H2S is formed from the amino acid cysteine by the action of cystathionine ?-synthase (CBS) with serine (Ser) as the by-product. As CBS is a calcium and calmodulin dependent enzyme, the

K. Qu; S. W. Lee; J. S. Bian; C.-M. Low; P. T.-H. Wong

2008-01-01

24

30 CFR 250.490 - Hydrogen sulfide.  

Code of Federal Regulations, 2010 CFR

... Poisonous Gas. Hydrogen Sulfide. 7 inches...the words âDanger-Hydrogen Sulfide-H2 S,â provided...Mud-return line receiver tank (possum belly); ...production process equipment, tanks, relief valves, burst...be invaded by atomic hydrogen when H2 S is...

2010-07-01

25

30 CFR 250.490 - Hydrogen sulfide.  

Code of Federal Regulations, 2010 CFR

... Poisonous Gas. Hydrogen Sulfide. 7 inches...the words âDanger-Hydrogen Sulfide-H2 S,â provided...Mud-return line receiver tank (possum belly); ...production process equipment, tanks, relief valves, burst...be invaded by atomic hydrogen when H2 S is...

2009-07-01

26

Centrifugal Distortion in Water and Hydrogen Sulfide.  

National Technical Information Service (NTIS)

It is the intent of this note to present specific results pertaining to the changes in molecular geometry of water and hydrogen sulfide which are induced by centrifugal effects in rotational states of the molecules. Hydrogen, deuterium, and tritium substi...

R. M. Garvey

1976-01-01

27

Method for the Decomposition of Hydrogen Sulfide.  

National Technical Information Service (NTIS)

Hydrogen sulfide is one of the most toxic of gases, even more harmful than phosgene and cyanide gases. It is also very corrosive and responsible for the rapid deterioration of equipment. In view of these harmful effects of hydrogen sulfide there has been ...

L. A. Haas

1974-01-01

28

Production of Hydrogen Sulfide by Streptomyces odorifer  

PubMed Central

By use of various trapping systems, as well as lead acetate papers, Streptomyces odorifer was shown to produce hydrogen sulfide. Other sulfur-containing compounds may be produced by S. odorifer, but the amounts obtained were too small for detailed analysis. It was suggested that hydrogen sulfide might be a part of the earthy-odor complex produced by S. odorifer.

Collins, R. P.; Gaines, H. D.

1964-01-01

29

Catalyst and process for oxidizing hydrogen sulfide  

Microsoft Academic Search

Catalysts comprising bismuth and vanadium components are highly active and stable, especially in the presence of water vapor, for oxidizing hydrogen sulfide to sulfur or SOâ. Such catalysts have been found to be especially active for the conversion of hydrogen sulfide to sulfur by reaction with oxygen or SOâ.

R. H. Hass; Fullerton; J. W. Ward; L. Yorba

1984-01-01

30

Hydrogen recovery from hydrogen sulfide by oxidation and by decomposition  

SciTech Connect

Selective oxidation of hydrogen sulfide to hydrogen and sulfur oxides in a two-step process and the catalytic decomposition of hydrogen sulfide were studied for the recovery of hydrogen from hydrogen sulfide. Platinum, when adequately dispersed on a silica support, was found to be effective in reacting with hydrogen sulfide to produce hydrogen and platinum sulfide at 500 C. The platinum sulfide could then be treated with oxygen at 400 C to release sulfur oxides and regenerate the platinum. However, oxidation of sulfur dioxide to trioxide, retention of oxygen by platinum, and adsorption of hydrogen sulfide by the silica support also occurred, which resulted in a minor loss in hydrogen yield. In the decomposition of hydrogen sulfide, platinum sulfide was found to be catalytically active. The equilibrium hydrogen yields were measured experimentally over the range 350--650 C and compared with the values calculated on the basis of a model that included the S, allotropes, the H[sub 2]S[sub n] sulfanes, and HS. The values agreed well at low temperatures but deviated from each other up to 20% at high temperatures.

Yang, B.L.; Kung, H.H. (Northwestern Univ., Evanston, IL (United States). Ipatieff Lab. and Chemical Engineering Dept.)

1994-05-01

31

The mass budgets of carbonyl sulfide, dimethyl sulfide, carbon disulfide and hydrogen sulfide  

Microsoft Academic Search

This study investigates the distribution and magnitudes of the global sources and sinks of carbonyl sulfide (OCS), hydrogen sulfide (H2S), carbon disulfide (CS2), and dimethyl sulfide (DMS). For OCS, H2S and CS2, balanced mass budgets are proposed. An inventory of sources has been assembled for dimethyl sulfide (DMS). For OCS, total global sources and sinks are estimated as 1.31±0.25 and

Simon F. Watts

2000-01-01

32

Hydrogen sulfide corrosion can be controlled  

Microsoft Academic Search

Hydrogen sulfide is one of the most serious corrosion agents encountered in oil production. Dangerous problems result from sulfide cracking failures. As a general rule, such failures can be prevented by restricting the steel yield strength to 90,000 psi maximum. Widespread corrosion in waterfloods and low pressure crude production can often be controlled entirely by rigorous exclusion of dissolved oxygen.

Hudgins; C. M. Jr

1970-01-01

33

Ridding Groundwater of Hydrogen Sulfide. Part 1.  

ERIC Educational Resources Information Center

|This article is the first in a series reviewing the problems associated with hydrogen sulfide in drinking water sources. Discussion centers on identification of a cost-effective balance between aeration and chlorination treatment operations. (AS)|

Lochrane, Thomas G.

1979-01-01

34

Ridding Groundwater of Hydrogen Sulfide. Part 1.  

ERIC Educational Resources Information Center

This article is the first in a series reviewing the problems associated with hydrogen sulfide in drinking water sources. Discussion centers on identification of a cost-effective balance between aeration and chlorination treatment operations. (AS)

Lochrane, Thomas G.

1979-01-01

35

Infrared spectroscopy of solid hydrogen sulfide and deuterium sulfide.  

PubMed

The infrared spectra of solid hydrogen sulfide (H2S) and deuterium sulfide (D2S) were collected at very low temperatures. Vapor deposition of thin films at the lowest temperature of 10 K produced amorphous solids while deposition at 70 K yielded the crystalline phase III. Infrared interference fringe patterns produced by the films during deposition were used to determine the film thickness. Careful measurement of the integrated absorbance peaks, along with the film thickness, allowed determination of the integrated band intensities. This report represents the first complete presentation of the infrared spectra of the amorphous solids. Observations of peaks near 3.915 and 1.982 microm (ca. 2554 and 5045 cm(-1), respectively) may be helpful in the conclusive identification of solid hydrogen sulfide on the surface of Io, a moon of Jupiter. PMID:16970373

Fathe, Kristin; Holt, Jennifer S; Oxley, Susan P; Pursell, Christopher J

2006-09-21

36

Hydrogen sulfide and translational medicine.  

PubMed

Hydrogen sulfide (H2S) along with carbon monoxide and nitric oxide is an important signaling molecule that has undergone large numbers of fundamental investigations. H2S is involved in various physiological activities associated with the regulation of homeostasis, vascular contractility, pro- and anti-inflammatory activities, as well as pro- and anti-apoptotic activities etc. However, the actions of H2S are influenced by its concentration, reaction time, and cell/disease types. Therefore, H2S is a signaling molecule without definite effect. The use of existing H2S donors is limited because of the instant release and short lifetime of H2S. Thus, translational medicine involving the sustained and controlled release of H2S is of great value for both scientific and clinical uses. H2S donation can be manipulated by different ways, including where H2S is given, how H2S is donated, or the specific structures of H2S-releasing drugs and H2S donor molecules. This review briefly summarizes recent progress in research on the physiological and pathological functions of H2S and H2S-releasing drugs, and suggests hope for future investigations. PMID:24096643

Guo, Wei; Cheng, Ze-Yu; Zhu, Yi-Zhun

2013-10-01

37

Hydrogen sulfide: neurophysiology and neuropathology.  

PubMed

Hydrogen sulfide (H(2)S) was known to be a toxic gas and an environmental hazard for many decades. However, it is now recognized that H(2)S may serve as a gaseous mediator that is endogenously produced to influence biological functions in mammalian. Together with nitric oxide and carbon monoxide, it forms the group of mediators that has been termed the "gasotransmitters." The past decade has seen an exponential growth of scientific interest in the physiological and pathological significance of H(2)S especially with respect to its role in the central nervous system and the cardiovascular system. In the central nervous system, H(2)S facilitates long-term potentiation and regulates intracellular calcium concentration and pH level in brain cells. Intriguingly, H(2)S produces antioxidant, anti-inflammatory, and antiapoptotic effects that may have relevance to neurodegenerative disorders. Abnormal generation and metabolism of H(2)S have been reported in the pathogenesis of ischemic stroke, Alzheimer's disease, Parkinson's disease, and recurrent febrile seizure. Exogenously applied H(2)S is demonstrated to have value for the treatment of febrile seizure and Parkinson's disease. This article presents an overview of current knowledge of H(2)S in relation to brain functions, with a special emphasis on its neuroprotective effects and the underlying cellular and molecular mechanisms. PMID:20812864

Hu, Li-Fang; Lu, Ming; Hon Wong, Peter Tsun; Bian, Jin-Song

2011-02-18

38

Terahertz spectroscopy of hydrogen sulfide  

NASA Astrophysics Data System (ADS)

Pure rotational transitions of hydrogen sulfide (H2S) in its ground and first excited vibrational states have been recorded at room temperature. The spectrum comprises an average of 1020 scans at 0.005 cm?1 resolution recorded in the region 45–360 cm?1 (1.4 to 10.5 THz) with a globar continuum source using a Fourier transform spectrometer located at the AILES beamline of the SOLEIL synchrotron. Over 2400 rotational lines have been detected belonging to ground vibrational state transitions of the four isotopologues H232S, H233S, H234S, and H236S observed in natural abundance. 65% of these lines are recorded and assigned for the first time, sampling levels as high as J=26 and Ka=17 for H232S. 320 pure rotational transitions of H232S in its first excited bending vibrational state are recorded and analysed for the first time and 86 transitions for H234S, where some of these transitions belong to new experimental energy levels. Rotational constants have been fitted for all the isotopologues in both vibrational states using a standard effective Hamiltonian approach. Comprehensive comparisons are made with previously available data as well as the data available in HITRAN, CDMS, and JPL databases. The 91 transitions assigned to H236S give the first proper characterization of its pure rotational spectrum.

Azzam, Ala'a. A. A.; Yurchenko, Sergei N.; Tennyson, Jonathan; Martin-Drumel, Marie-Aline; Pirali, Olivier

2013-11-01

39

Hydrogen Sulfide as a Gasotransmitter  

PubMed Central

Nitric oxide (NO) and carbon monoxide (CO) are well established as messenger molecules throughout the body, gasotransmitters, based on striking alterations in mice lacking the appropriate biosynthetic enzymes. Hydrogen sulfide (H2S) is even more chemically reactive, but till recently there was little definitive evidence for its physiologic formation. Cystathionine ?-synthase (CBS, EC 4.2.1.22), and Cystathionine ?-lyase (CSE; EC 4.4.1.1), also known as cytathionase, can generate H2S from cyst(e)ine. Very recent studies with mice lacking these enzymes have established that CSE is responsible for H2S formation in the periphery, while in the brain CBS is the biosynthetic enzyme. Endothelial-derived relaxing factor (EDRF) activity is reduced 80% in the mesenteric artery of mice with deletion of CSE, establishing H2S as a major physiologic EDRF. H2S appears to signal predominantly by S-sulfhydrating cysteines in its target proteins, analogous to S-nitrosylation by NO. Whereas S-nitrosylation typically inhibits enzymes, S-sulfhydration activates them. S-nitrosylation basally affects 1–2% of its target proteins, while 10–25% of H2S target proteins are S-sulfhydrated. In summary, H2S appears to be a physiologic gasotransmitter of comparable importance to NO and CO.

Gadalla, Moataz M.; Snyder, Solomon H.

2010-01-01

40

Hydrogen sulfide and translational medicine  

PubMed Central

Hydrogen sulfide (H2S) along with carbon monoxide and nitric oxide is an important signaling molecule that has undergone large numbers of fundamental investigations. H2S is involved in various physiological activities associated with the regulation of homeostasis, vascular contractility, pro- and anti-inflammatory activities, as well as pro- and anti-apoptotic activities etc. However, the actions of H2S are influenced by its concentration, reaction time, and cell/disease types. Therefore, H2S is a signaling molecule without definite effect. The use of existing H2S donors is limited because of the instant release and short lifetime of H2S. Thus, translational medicine involving the sustained and controlled release of H2S is of great value for both scientific and clinical uses. H2S donation can be manipulated by different ways, including where H2S is given, how H2S is donated, or the specific structures of H2S-releasing drugs and H2S donor molecules. This review briefly summarizes recent progress in research on the physiological and pathological functions of H2S and H2S-releasing drugs, and suggests hope for future investigations.

Guo, Wei; Cheng, Ze-yu; Zhu, Yi-zhun

2013-01-01

41

Method for the removal of carbonyl sulfide from liquid propane  

SciTech Connect

A method for the removal of carbonyl sulfide from liquid propane under liquid-liquid contact conditions by mixing liquid propane containing carbonyl sulfide as an impurity with 2-(2-aminoethoxy) ethanol as the principal agent for the carbonyl sulfide removal. The 2(2-aminoethoxy) ethanol is reclaimed and reused for further carbonyl sulfide removal. 5 claims.

McClure, G.

1980-06-17

42

Hydrogen sulfide effects on stomatal apertures  

PubMed Central

Hydrogen sulfide (H2S) has recently been reported to be a signaling molecule in plants. It has been well established that is has such roles in animals and it has been suggested that it is included into the group of gasotransmitters. We have recently shown that hydrogen sulfide causes stomatal opening in the model plant Arabidopsis thaliana. H2S can be supplied to the plant tissues from donors such as sodium hydrosulfide (NaSH) or more recently from slow release H2S donor molecules such as GYY4137. Both give similar effects, that is, they cause stomatal opening. Furthermore both H2S donors reduced the accumulation of nitric oxide (NO) induced by abscisic acid (ABA) treatment of leaf tissues. Here similar work has been repeated in a crop plant, Capsicum anuum, and similar data has been obtained, suggesting that such effects of hydrogen sulfide on plants is not confined to model species.

Lisjak, Miroslav; Teklic, Tihana; Wilson, Ian D; Wood, Mark E; Whiteman, Matt

2011-01-01

43

Preliminary Air Pollution Survey of Hydrogen Sulfide: A Literature Review.  

National Technical Information Service (NTIS)

This is a preliminary literature review representing present knowledge of hydrogen sulfide and its effects on humans, animals, plants and materials. Hydrogen sulfide is a colorless gas that has an obnoxious odor at low concentrations. The odor threshold i...

S. Miner

1969-01-01

44

The diagenesis of carbohydrates by hydrogen sulfide  

NASA Astrophysics Data System (ADS)

Carbohydrates react with hydrogen sulfide under low temperature (100° to 200°C) yielding a variety of organosulfur compounds including thiophenes, thiols, sulfides and sulfones. A polymer is also produced, whose elemental composition is within the range of natural coals. When reductive dehydration is carried out in the presence of hydrocarbon, organosulfur compounds are formed in the carbon number range of the hydrocarbon used. In these processes, an active hydrogen transfer catalyst is produced which facilitates the passage of hydrogen between normal paraffins and saccharide units, distributing sulfur between these two families primarily in the form of thiophene rings. The simplicity of these systems - H 2S, carbohydrates, H 2O, hydrocarbon - and the facility of the chemistry would suggest that the carbohydrates and hydrogen sulfide may be important agents in the diagenetic processes leading to petroleum and coal. Carbohydrate reduction by hydrogen sulfide may constitute an important route through which certain organosulfur compounds found in petroleum and coal entered these materials in early diagenesis.

Mango, Frank D.

1983-08-01

45

Method for reconditioning bacteria-contaminated hydrogen sulfide removal systems  

Microsoft Academic Search

A method, applicable to hydrogen sulfide removal systems which employ a regenerable aqueous washing solution capable of absorbing hydrogen sulfide and converting that hydrogen sulfide to elemental sulfur, is provided for reconditioning such systems after they have become contaminated with sulfur-feeding bacteria and\\/or for maintaining such systems substantially free of such bacteria. In the method of the invention, the aqueous

1985-01-01

46

Microwave production of hydrogen and sulfur from hydrogen sulfide wastes  

SciTech Connect

A waste-treatment process is being developed that uses ``cold`` microwave plasma-chemical reactions to split hydrogen sulfide into elemental hydrogen and sulfur. A clean sulfur product can be recovered and sold, while product gases are purified and separated into seams containing hydrogen, hydrogen sulfide for recycle, and the process purge containing carbon dioxide and water. Experiments with pure hydrogen sulfide at 0.5 to 1.5 L/min flow rates and microwave powers of 400 to 1000 W confirmed that conversions of over 90% per pass at process energy requirements approaching 5 kcal/mol are possible. Experiments with impurities typical of petroleum refinery waste hydrogen sulfide streams have demonstrated that these impurities are compatible with the plasma dissociation process and that they do not create new waste treatment problems. This technology has a long-term potential for saving 40 to 70 {times} 10{sup 12} Btu/yr in the refining industry, for an economic savings of $500 million to $1000 million annually. Although the microwave process should show particular advantages for the petroleum refining industry, the low capital costs and modular nature of the new process should make it economically attractive in connection with the small-scale waste-treatment technologies currently used in the natural gas industry. Currently, in the U.S.S.R., a 500-kW demonstration microwave hydrogen sulfide treatment unit operating at near atmospheric pressure is being tested at the natural gas fields in Orenberg. 3 refs.

Harkness, J.B.L.; Doctor, R.D.

1992-01-01

47

Microwave production of hydrogen and sulfur from hydrogen sulfide wastes  

SciTech Connect

A waste-treatment process is being developed that uses cold'' microwave plasma-chemical reactions to split hydrogen sulfide into elemental hydrogen and sulfur. A clean sulfur product can be recovered and sold, while product gases are purified and separated into seams containing hydrogen, hydrogen sulfide for recycle, and the process purge containing carbon dioxide and water. Experiments with pure hydrogen sulfide at 0.5 to 1.5 L/min flow rates and microwave powers of 400 to 1000 W confirmed that conversions of over 90% per pass at process energy requirements approaching 5 kcal/mol are possible. Experiments with impurities typical of petroleum refinery waste hydrogen sulfide streams have demonstrated that these impurities are compatible with the plasma dissociation process and that they do not create new waste treatment problems. This technology has a long-term potential for saving 40 to 70 {times} 10{sup 12} Btu/yr in the refining industry, for an economic savings of $500 million to $1000 million annually. Although the microwave process should show particular advantages for the petroleum refining industry, the low capital costs and modular nature of the new process should make it economically attractive in connection with the small-scale waste-treatment technologies currently used in the natural gas industry. Currently, in the U.S.S.R., a 500-kW demonstration microwave hydrogen sulfide treatment unit operating at near atmospheric pressure is being tested at the natural gas fields in Orenberg. 3 refs.

Harkness, J.B.L.; Doctor, R.D.

1992-01-01

48

Fatal occupational inhalation of hydrogen sulfide  

Microsoft Academic Search

A young man aged 22 years, a sewer worker by profession, died after massive inhalation of hydrogen sulfide while at work. He was rescued by the emergency services and admitted to the critical care department, where he died due to massive myocardial necrosis less than 24h after admission.In this case, where the causes of the accident were not clearly established,

A. Christia-Lotter; C. Bartoli; M.-D. Piercecchi-Marti; D. Demory; A.-L. Pelissier-Alicot; A. Sanvoisin; G. Leonetti

2007-01-01

49

Comparison of Hydrogen Sulfide Analysis Techniques  

ERIC Educational Resources Information Center

|A summary and critique of common methods of hydrogen sulfide analysis is presented. Procedures described are: reflectance from silver plates and lead acetate-coated tiles, lead acetate and mercuric chloride paper tapes, sodium nitroprusside and methylene blue wet chemical methods, infrared spectrophotometry, and gas chromatography. (BL)|

Bethea, Robert M.

1973-01-01

50

Process for producing hydrogen and carbonyl sulfide from hydrogen sulfide and carbon monoxide using a heteropolyanionic metal complex catalyst  

SciTech Connect

Hydrogen and carbonyl sulfide are produced by a process comprising contracting gaseous hydrogen sulfide with gaseous carbon monoxide in the presence of a heteropolymolybdate or tungstate complex. Use of these catalysts reduce the amount of by-product carbon dioxide and methane formation and thus enhance the make of hydrogen and carbonyl sulfide.

Kuch, Ph. L.

1984-12-18

51

Mechanisms of hydrogen sulfide removal with steel making slag.  

PubMed

In the present study, we experimentally investigated the removal of hydrogen sulfide using steel-making slag (SMS) and clarified the mechanism of hydrogen sulfide removal with the SMS. The results proved that SMS is able to remove hydrogen sulfide dissolved in water, and the maximum removal amount of hydrogen sulfide per unit weight of the SMS for 8 days was estimated to be 37.5 mg S/g. The removal processes of hydrogen sulfide were not only adsorption onto the SMS, but oxidation and precipitation as sulfur. The chemical forms of sulfide adsorbed onto the SMS were estimated to be sulfur and manganese sulfide in the ratio of 81% and 19%, respectively. It is demonstrated here that the SMS is a promising material to remediate organically enriched coastal sediments in terms of removal of hydrogen sulfide. Furthermore, using SMS is expected to contribute to development of a recycling-oriented society. PMID:22894171

Kim, Kyunghoi; Asaoka, Satoshi; Yamamoto, Tamiji; Hayakawa, Shinjiro; Takeda, Kazuhiko; Katayama, Misaki; Onoue, Takasumi

2012-09-07

52

Wheat straw cover for reducing ammonia and hydrogen sulfide emissions from dairy manure storage  

SciTech Connect

Analysis of the use of a wheat straw cover for reducing ammonia and hydrogen sulfide emissions from liquid manure was conducted in both a laboratory and a pilot system. Two straw covers with different thicknesses (5 cm and 10 cm) were evaluated for their effectiveness in reducing odorous gas emissions. The rates of ammonia and hydrogen sulfide emissions from the treatments were monitored; concentrations of ammonia, dissolved sulfide, chemical oxygen demand (COD), and pH of the liquid manure were measured. Additionally, the overall mass transfer coefficients of ammonia and hydrogen sulfide were calculated for the conditions of the experiment. The results demonstrated that both the 5-cm and 10-cm straw covers were effective in reducing ammonia and hydrogen sulfide emissions from manure storage. In the laboratory tests, when a crust formed on the manure surface within three to four weeks after the straw application, ammonia emissions were reduced by up to 95%. A similar trend was observed in the pilot experiments in the field. Hydrogen sulfide emissions were suppressed by 95% with the wheat straw cover. The mass transfer coefficients of hydrogen sulfide with the straw covers were significantly lower than those of the control, which indicated the effectiveness of a straw cover as a physical barrier for reducing hydrogen sulfide emissions. Reduced pH and decreased ammonia that biological reactions might also be a factor contributing to the emission reductions.

Xue, S.K.; Hermanson, R.E.

1999-08-01

53

Method for direct production of carbon disulfide and hydrogen from hydrocarbons and hydrogen sulfide feedstock  

DOEpatents

A method for converting hydrocarbons and hydrogen sulfide to carbon disulfide and hydrogen is provided comprising contacting the hydrocarbons and hydrogen sulfide to a bi-functional catalyst residing in a controlled atmosphere for a time and at a temperature sufficient to produce carbon disulfide and hydrogen. Also provided is a catalyst for converting carbon sulfides and hydrogen sulfides to gasoline range hydrocarbons comprising a mixture containing a zeolite catalyst and a hydrogenating catalyst.

Miao, Frank Q.; Erekson, Erek James

1998-12-01

54

Hydrogen sulfide determination by solid surface luminescence.  

PubMed

In the analytical system suggested, atmospheric hydrogen sulfide reacts with the surface of a filter paper treated with aqueous cadmium chloride and yields a luminescent species whose intensity can be correlated with the analyte concentration in ambient air. It was shown that the luminescent species are CdS solid particles which were formed in a well defined size. The paper luminescence was also tried on polymeric surfaces; polyethyleneoxide, polyvinyl alcohol, ethylcellulose and carboxymethylcellulose were found to give a similar luminescence signal. The system can be used on the tip of an optical fiber for an irreversible, cumulative type of analytical device for hydrogen sulfide determination. The 3s detection limit for the paper luminescence detection system was 7.8 ppb H(2)S. PMID:15045337

Ero?lu, A E; Volkan, M; Bayramh, E; Ataman, O Y; Mark, H B

1996-06-01

55

Catalytic removal of hydrogen sulfide from gases  

SciTech Connect

In a catalytic oxidation-reduction process of removing hydrogen sulfide gas from a gaseous fluid stream, the improved step of contacting a gaseous stream containing hydrogen sulfide gas with an aqueous solution containing iron chelate catalyst having iron in the ferric state wherein the iron chelate catalyst comprises at least two iron chelating agents with at least one of said agents being an amine compound selected from the group consisting of polyamino polycarboxylic acids, polyamino alkyl polycarboxylic acids, polyamino hydroxyalkyl polycarboxylic acids, and poly(Phosphonoalkyl) amines, and their alkali metal salts and another of said iron chelating agents being selected from the group of polyhydroxy compounds consisting of monosaccharides, disaccharides, reduced monosaccharides, reduced disaccharides, monosaccharide acids, disaccharide acids, and their alkali metal salts; and said solution having a ph ranging between about ph 5.5 and about ph 13.

Thompson, R.B.

1980-02-19

56

Selective removal of carbonyl sulfide from a hydrogen sulfide containing gas mixture  

SciTech Connect

This patent describes a process for the selective removal of carbonyl sulfide from a gas mixture also comprising hydrogen sulfide. It comprises contacting the gas mixture with an absorbent comprising from about 35% w to about 55% w of a tertiary amine; from about 5% w to about 15% w of water, and the balance being a physical co-solvent; regenerating the loaded absorbent to remove substantially all of the carbonyl sulfide and most of the hydrogen sulfide to provide a lean absorbent containing hydrogen sulfide in an amount of 0.2% w to 2% w; and recycling the lean absorbent to the contacting step.

Souby, M.C.

1990-12-25

57

Hydrogen sulfide protects neurons from oxidative stress  

Microsoft Academic Search

Hydrogen sulfide (H2S), which is a well-known toxic gas, is found in relatively high concentrations in the brain. Although a neuromodulatory role of H2S has been demonstrated, little is known of its other biological functions. Here we show that H2S protects primary cultures of neurons from death in a well-studied model of oxidative stress caused by glutamate, a process called

Yuka Kimura; Hideo Kimura

2004-01-01

58

Hydrogen sulfide: its production, release and functions  

Microsoft Academic Search

Hydrogen sulfide (H2S), which is a well-known toxic gas, has been recognized as a signal molecule as well as a cytoprotectant. It is produced\\u000a by three enzymes, cystathionine ?-synthase, cystathionine ?-lyase and 3-mercaptopyruvate sulfurtransferase along with cysteine\\u000a aminotransferase. In addition to an immediate release of H2S from producing enzymes, it can be stored as bound sulfane sulfur, which may release

Hideo Kimura

2011-01-01

59

High temperature regenerable hydrogen sulfide removal agents  

Microsoft Academic Search

A system for high temperature desulfurization of coal-derived gases using regenerable sorbents. One sorbent is stannic oxide (tin oxide, SnO.sub.2), the other sorbent is a metal oxide or mixed metal oxide such as zinc ferrite (ZnFe.sub.2 O.sub.4). Certain otherwise undesirable by-products, including hydrogen sulfide (H.sub.2 S) and sulfur dioxide (SO.sub.2) are reused by the system, and elemental sulfur is produced

Robert J

1993-01-01

60

Polymeric inhibitors of hydrogen sulfide corrosion  

Microsoft Academic Search

The aggregation properties of hydrophobized polyethyleneimines and their inhibitory activity in hydrogen sulfide and carbon\\u000a dioxide corrosion of iron were studied. The critical association concentrations, the radii of polymer aggregates formed in\\u000a aqueous and aqueous alcohol solutions of polyethyleneimines, were determined. It was shown that these polymers at a concentration\\u000a of 10–25 mg\\/l display a high inhibiting activity in the

D. B. Kudryavtsev; A. R. Panteleeva; A. V. Yurina; S. S. Lukashenko; Yu. P. Khodyrev; R. M. Galiakberov; D. N. Khaziakhmetov; L. A. Kudryavtseva

2009-01-01

61

Recovery of hydrogen from hydrogen sulfide with metals or metal sulfides  

NASA Astrophysics Data System (ADS)

Two types of reactions for the recovery of hydrogen from hydrogen sulfide using metals or metal sulfides are investigated. The first type of reaction, which involved the sulfurization of metals or metal sulfides with H2S and the thermal decomposition of the products into hydrogen, elemental sulfur and the original metals or metal sulfide, was studied by the measurement of H2 evolution in a packed bed of powders of Ag, FeS, Co9S8, Ni3S2 and various sulfide mixtures. The second type of reaction involves the sulfurization of a metal by H2S and the recovery of the metal by the oxidation of the metal sulfides formed, and was studied for the case of molten lead, molten lead with the addition of Ni or Co, Ag, Cu and Ni powders, and molten Ag-Bi alloy. Extents of reaction and temperature dependence were determined for each step of the reactions, and the repeatability of the cycles was examined.

Kiuchi, H.; Nakamura, I.; Funaki, K.; Tanaka, T.

62

Free and acid-labile hydrogen sulfide concentrations in mouse tissues: anomalously high free hydrogen sulfide in aortic tissue.  

PubMed

Endogenously produced hydrogen sulfide is thought to function as an intracellular messenger. There is, however, little information on tissue concentrations of free hydrogen sulfide, the putative messenger form of this molecule, versus that of the bound (acid-labile) form. The present report describes the application of a novel technique to measure free and acid-labile hydrogen sulfide in mouse tissues. Very low free hydrogen sulfide concentrations (<0.050 ?mol/kg) were observed in brain, liver, blood, heart, kidney, striated muscle, and esophagus. Aortic concentrations of free hydrogen sulfide were 20 to 100 times greater than that of the other tissues. Acid-labile hydrogen sulfide concentrations were multiple orders of magnitude greater than that of the free form in every tissue other than aorta. Previous reports of tissue hydrogen sulfide concentrations of 30 to >100 ?mol/kg measured bound rather than free hydrogen sulfide, the observation that aorta contains anomalously high free hydrogen sulfide concentrations lends support for a vasodilator function for this molecule, and the very low free hydrogen sulfide concentrations in most tissues seemingly requires intermediation of a yet to be described receptor-like mechanism if this molecule is to serve as a gasotransmitter. PMID:20812866

Levitt, Michael D; Abdel-Rehim, Mohamed Saber; Furne, Julie

2011-02-03

63

Using Carbon Nanotubes to Absorb Low-Concentration Hydrogen Sulfide in Fluid  

Microsoft Academic Search

Hydrogen sulfide is a colorless and flammable gas under room temperature. Usually hydrogen sulfide is considered to be toxic; however, the recent research revealed that hydrogen sulfide in the cardiovascular system plays the role of a vascular dilator. The physiological role of hydrogen sulfide depends on its in vivo level. As such, the measurement of hydrogen sulfide with nano-quantity resolution

X. C. Wu; W. J. Zhang; D. Q. Wu; R. Sammynaiken; R. Wang; Q. Yang

2006-01-01

64

Hydrogen sulfide and carbon dioxide removal from dry fuel gas streams using an ionic liquid as a physical solvent  

SciTech Connect

The mole fraction solubilities (x{asterisk}) and volumetric liquid-side mass-transfer coefficients (kLa) for H{sub 2}S and CO{sub 2} in the ionic liquid, TEGO IL K5, (a quaternary ammonium polyether) were measured under different pressures (up to 30 bar) and temperatures (up to 500 K) in a 4 L ZipperClave agitated reactor. CO{sub 2} and N{sub 2}, as single gases, and a H{sub 2}S/N{sub 2} gaseous mixture were used in the experiments. The solubilities of H{sub 2}S and CO{sub 2} were found to increase with pressure and decrease with temperature within the experimental conditions used. The H{sub 2}S solubilities in the ionic liquid (IL) were greater than those of CO{sub 2} within the temperature range investigated (300-500 K) up to a H{sub 2}S partial pressure of 2.33 bar. Hence, the IL can be effectively used to capture both H{sub 2}S and CO{sub 2} from dry fuel gas stream within the temperature range from 300 to 500 K under a total pressure up to 30 bar. The presence of H{sub 2}S in the H{sub 2}S/N{sub 2} mixture created mass-transfer resistance, which decreased k{sub L}{alpha} values for N{sub 2}. The k{sub L}{alpha} and x{asterisk} values of CO{sub 2} were found to be greater than those of N{sub 2} in the IL, which highlight the stronger selectivity of this physical solvent toward CO{sub 2} than toward N{sub 2}. In addition, within the temperature range from 300 to 500 K, the solubility and k{sub L}{alpha} of H{sub 2}S in the IL were greater than those of CO{sub 2}, suggesting that not only can H{sub 2}S be more easily captured from dry fuel gas streams but also a shorter absorber can be employed for H{sub 2}S capture than that for CO{sub 2}. 56 refs., 8 figs., 4 tabs.

Yannick J. Heintz; Laurent Sehabiague; Badie I. Morsi; Kenneth L. Jones; David R. Luebke; Henry W. Pennline [United States Department of Energy (U.S. DOE), Pittsburgh, PA (United States). National Energy Technology Laboratory

2009-09-15

65

40 CFR 60.648 - Optional procedure for measuring hydrogen sulfide in acid  

Code of Federal Regulations, 2010 CFR

...Optional procedure for measuring hydrogen sulfide in acid] 40 PROTECTION...Optional procedure for measuring hydrogen sulfide in acid gas--Tutwiler...method consists of titrating hydrogen sulfide in a gas sample...

2009-07-01

66

Japanese experience of hydrogen sulfide: the suicide craze in 2008  

Microsoft Academic Search

Most of hydrogen sulfide poisoning has been reported as industrial accidents in Japan. However, since January 2008, a burgeoning of suicide attempts using homemade hydrogen sulfide gas has become evident. By April 2008, the fad escalated into a chain reaction nationwide. Mortality of the poisoning was very high. There were 220 cases of attempted gas suicides during the period of

Daiichi Morii; Yasusuke Miyagatani; Naohisa Nakamae; Masaki Murao; Kiyomi Taniyama

2010-01-01

67

Hydrogen sulfide waste treatment by microwave plasma dissociation.  

National Technical Information Service (NTIS)

A new waste-treatment technology for hydrogen sulfide using a microwave-generated plasma to dissociate hydrogen sulfide appears to have a substantial economic edge over the current industrial technology. The advantage of the plasma process is that it can ...

J. B. L. Harkness A. J. Gorski E. J. Daniels

1990-01-01

68

Disequilibrium of Hydrogen Sulfide in Ground Water by Aeration.  

National Technical Information Service (NTIS)

This study examines removal of hydrogen sulfide gas by aeration as a result of bubbling air through water in the well before it is pumped out of the ground. The field study demonstrated that a substantial amount of hydrogen sulfide gas could be successful...

J. D. Ritchey

1981-01-01

69

Cracking of Steels in Condensates Containing Hydrogen Sulfide.  

National Technical Information Service (NTIS)

Steel-D possesses a great tendency to crack in a hydrogen sulfide medium. The threshold load lies below 10 kgf/mm exp 2 . Lowering the medium pH will decrease the time until destruction. The concentration of hydrogen sulfide has little influence on the ti...

E. P. Zav'yalova O. K. Ioannidis R. A. Abdullin

1972-01-01

70

Hydrogen sulfide: its production and functions.  

PubMed

Endogenous levels of sulfide in the brain have been measured in rats, humans and bovines in 1989 and 1990, suggesting that H(2)S may have a physiological function. We demonstrated in 1996 that cystathionine ?-synthase can produce H(2)S in the brain and that H(2)S facilitates the induction of hippocampal long-term potentiation by enhancing the activity of NMDA receptors. The following year, we showed that another H(2)S-producing enzyme, cystathionine ?-lyase, is expressed in the thoracic aorta, portal vein and ileum and that H(2)S relaxes these tissues. We proposed that H(2)S may be a neuromodulator as well as a smooth muscle relaxant. In addition to a function as a signalling molecule, we demonstrated another function as a cytoprotectant in 2004. Hydrogen sulfide protects neurons from oxidative stress by reinstating the reduced glutathione levels. We recently demonstrated that a third H(2)S-producing enzyme, 3-mercaptopyruvate sulfurtransferase (3MST), is expressed in neurons and vascular endothelium. In addition to reinstating glutathione levels, H(2)S produced by 3MST, which is mainly localized to mitochondria, reduces reactive oxygen species generated in these organelles. PMID:21527544

Kimura, Hideo

2011-04-28

71

Protection by DIGAZFEN-I hydrogen-sulfide corrosion inhibitor  

Microsoft Academic Search

The performance of the new DIGAZFEN-I inhibitor for hydrogen sulfide corrosion in saline-hydrocarbon media, including the components (pyridine bases and fatty-acid aminoethers), was tested. Inhibition was determined gravimetrically on steel St3 in 3% NaCl solution and A-72 gasoline containing 1.5-2 g\\/liter hydrogen sulfide. Hydrogenation was determined indirectly from the plasticity changes in U9A steel strip specimens which were subsequently tested

V. F. Voloshin; O. P. Golosova; L. A. Mazalevskaya; V. S. Bakumenko; A. K. Sheinkman

1988-01-01

72

Hydrogen sulfide exposure in an adult male  

PubMed Central

Hydrogen sulfide (H2S) is responsible for many incidents of occupational toxic exposure, especially in the petroleum industry. The clinical effects of H2S depend on its concentration and the duration of exposure. H2S is immediately fatal when concentrations are over 500-1000 parts per million (ppm) but exposure to lower concentrations, such as 10-500 ppm, can cause various respiratory symptoms that range from rhinitis to acute respiratory failure. H2S may also affect multiple organs, causing temporary or permanent derangements in the nervous, cardiovascular, renal, hepatic, and hematological systems. We present a case of occupational exposure to H2S leading to multi-organ involvement, acute respiratory failure, organizing pneumonia, and shock resembling acute sepsis. The patient also developed mild obstructive and restrictive pulmonary disease and peripheral neuropathy.

Doujaiji, Bassam; Al-Tawfiq, Jaffar A.

2010-01-01

73

Hydrogen Production from Hydrogen Sulfide in IGCC Power Plants  

SciTech Connect

IGCC power plants are the cleanest coal-based power generation facilities in the world. Technical improvements are needed to help make them cost competitive. Sulfur recovery is one procedure in which improvement is possible. This project has developed and demonstrated an electrochemical process that could provide such an improvement. IGCC power plants now in operation extract the sulfur from the synthesis gas as hydrogen sulfide. In this project H{sub 2}S has been electrolyzed to yield sulfur and hydrogen (instead of sulfur and water as is the present practice). The value of the byproduct hydrogen makes this process more cost effective. The electrolysis has exploited some recent developments in solid state electrolytes. The proof of principal for the project concept has been accomplished.

Elias Stefanakos; Burton Krakow; Jonathan Mbah

2007-07-31

74

METABOLISM OF CARBONYL SULFIDE TO HYDROGEN SULFIDE IN INSECTS IS CATALYSED BY CARBONIC ANHYDRASE  

Microsoft Academic Search

Carbonyl sulfide (COS) is a new fumigant under development as a methyl bromide replacement for fumigation of durable commodities. COS has been shown to be relatively fast acting and toxic to a broad range of stored-product pests but little is known of the mechanism of toxicity of COS to insects. In rats, COS is metabolised to hydrogen sulfide by the

VICTORIA HARITOS

75

NEAR-CONTINUOUS MEASUREMENT OF HYDROGEN SULFIDE AND CARBONYL SULFIDE BY AN AUTOMATIC GAS CHROMATOGRAPH  

EPA Science Inventory

An automatic gas chromatograph with a flame photometric detector that samples and analyzes hydrogen sulfide and carbonyl sulfide at 30-s intervals is described. Temperature programming was used to elute trace amounts of carbon disulfide present in each injection from a Supelpak-S...

76

Microbial oxidation of mixtures of methylmercaptan and hydrogen sulfide.  

PubMed

Refinery spent-sulfidic caustic, containing only inorganic sulfides, has previously been shown to be amenable to biotreatment with Thiobacillus denitrificans strain F with complete oxidation of sulfides to sulfate. However, many spent caustics contain mercaptans that cannot be metabolized by this strict autotroph. An aerobic enrichment culture was developed from mixed Thiobacilli and activated sludge that was capable of simultaneous oxidation of inorganic sulfide and mercaptans using hydrogen sulfide (H2S) and methylmercaptan (MeSH) gas feeds used to simulate the inorganic and organic sulfur of a spent-sulfidic caustic. The enrichment culture was also capable of biotreatment of an actual mercaptan-containing, spent-sulfidic caustic but at lower rates than predicted by operation on MeSH and H2S fed to the culture in the gas phase, indicating that the caustic contained other inhibitory components. PMID:18576062

Subramaniyan, A; Kolhatkar, R; Sublette, K L; Beitle, R

1998-01-01

77

Low-Temperature Decomposition of Hydrogen Sulfide under the Conditions of Conjugate Chemisorption and Catalysis  

Microsoft Academic Search

Hydrogen sulfide H 2 S is one of the important byproducts of petroleum and gas processing, hydrometallurgy, and coal gasification. Gas condensate and natural gas fields contain large amounts of hydrogen sulfide (up to 50?80%). Hydrogen sulfide is a typical decomposition product of many mineral and organic substances. Along with this, hydrogen sulfide is a strong poison for living organisms.

A. N. Startsev; I. I. Zakharov; O. V. Voroshina; A. V. Pashigreva; V. N. Parmon

2004-01-01

78

Inhibition of Hydrogen Absorption by Steels in Wet Hydrogen Sulfide Refinery Environments  

Microsoft Academic Search

Hydrogen permeation and polarization measurements were used to investigate hydrogen adsorption by pressure vessel steels in refinery environments containing hydrogen sulfide (H[sub 2]S), ammonia (NH[sub 3]), and cyanide (CN[sup [minus

S. M. Wilhelm; D. M. Abayarathna

1994-01-01

79

REDUCING GENERATION OF BIOGENIC HYDROGEN SULFIDE IN SUGAR WASTEWATERS  

Microsoft Academic Search

In the manufacture of beet sugar, improving discharge water quality is a key objective for effective reuse of water for irrigation purposes. Problems associated with the discharge water includes generation of odors from biogenic hydrogen sulfide and ammonia, sludge buildup in ponds used for water retention and treatment due to precipitation of metal sulfides, and inadequate water discharge quality, in

Rakesh Govind; Dave Ferguson

80

Micro-aeration for hydrogen sulfide removal from biogas  

Microsoft Academic Search

The presence of sulfur compounds (e.g. protein, sulfate, thiosulfate, sulfite, etc.) in the feed stream generates highly corrosive and odorous hydrogen sulfide during anaerobic digestion. The high sulfide level in the biogas stream is not only poisonous to many novel metal catalysts employed in thermo-catalytic processes but also reduces the quality of methane to produce renewable energy. This study used

Thanapong Duangmanee

2009-01-01

81

Surface Analysis of Inhibitor Films Formed in Hydrogen Sulfide Medium  

Microsoft Academic Search

Steel samples exposed to a 5% sodium chloride solution containing 0.5% acetic acid saturated with hydrogen sulfide, with and without imidazole as an inhibitor, were analyzed by X-ray photoelectron spectroscopy and secondary ion mass spectrometry. The metal surface was covered initially by a layer of iron sulfide or oxide. This layer, in turn, was covered by layers in which Fe

V. S. Sastri; M. S. Elboujdaini; J. R. Perumareddi; J. R. Brown

1996-01-01

82

An Experiment in Autotrophic Fermentation: Microbial Oxidation of Hydrogen Sulfide.  

ERIC Educational Resources Information Center

|Described is an experiment which uses an autotrophic bacterium to anaerobically oxidize hydrogen sulfide to sulfate in a batch-stirred tank reactor. Discusses background information, experimental procedure, and sample results of this activity. (CW)|

Sublette, Kerry L.

1989-01-01

83

[Activity of hydrogen sulfide production enzymes in kidneys of rats].  

PubMed

An experimental research of activity and kinetic descriptions of enzymes participating in formation of hydrogen sulfide in the kidney of rats has been carried out. It was established that cystein, homocystein and thiosulphate are the basic substrates for hydrogen sulfide synthesis. The higest activity for hydrogen sulfide production belongs to thiosulfate-dithiolsulfurtransferase and cysteine aminotransferase, less activity is characteristic of cystathionine beta-synthase and cystathio-nine gamma-lyase. The highest affinity to substrate is registered for thiosulfate-dithiolsulfurtransferase and cystathionine gamma-lyase. It is discovered that the substrate inhibition is typical of all hydrogen sulfide formation enzymes, although this characteristic is the most expressed thiosulfat-dithiolsulfurtransferase. PMID:20387629

Mel'nyk, A V; Pentiuk, O O

84

An Experiment in Autotrophic Fermentation: Microbial Oxidation of Hydrogen Sulfide.  

ERIC Educational Resources Information Center

Described is an experiment which uses an autotrophic bacterium to anaerobically oxidize hydrogen sulfide to sulfate in a batch-stirred tank reactor. Discusses background information, experimental procedure, and sample results of this activity. (CW)

Sublette, Kerry L.

1989-01-01

85

Oxygen-hydrogen sulfide intermediate layer of the Black Sea  

SciTech Connect

Spatial and vertical boundaries were studied for the oxygen-hydrogen sulfide intermediate layer in the Black Sea. The wind has a great influence on the thermohaline structure of the Danube coastal waters. It causes strong out-and-influx processes and up-welling of hydrogen sulfide waters of the intermediate layer in the north-western part of the Black Sea, which is supposed to be one of the reasons for the ecological equilibrium disturbance in this region.

Timoshchuk, V.I.; Risik, N.S.

1980-01-01

86

Removal of carbonyl sulfide from liquid hydrocarbon streams  

SciTech Connect

Carbonyl sulfide is removed from propane and other similar liquefied petroleum gas products by mixing liquid methanol with the untreated liquefied gas and then contacting the liquid mixture with solid potassium hydroxide.

Damron, E.; Mick, M.B.; Woodall, R.M.

1981-09-22

87

Measurement and biological significance of the volatile sulfur compounds hydrogen sulfide, methanethiol and dimethyl sulfide in various biological matrices  

Microsoft Academic Search

This review deals with the measurement of the volatile sulfur compounds hydrogen sulfide, methanethiol and dimethyl sulfide in various biological matrices of rats and humans (blood, serum, tissues, urine, breath, feces and flatus). Hydrogen sulfide and methanethiol both contain the active thiol (–SH) group and appear in the free gaseous form, in the acid-labile form and in the dithiothreitol-labile form.

Albert Tangerman

2009-01-01

88

Sulfidation of zinc by traces of hydrogen sulfide in air  

SciTech Connect

The effect of H{sub 2}S in the sub-parts per million range on the atmospheric corrosion of zinc has been investigated in the laboratory. Each sample was exposed individually to air with careful control of pollutant concentration, relative humidity, and flow conditions. Monitoring of H{sub 2}S concentration at the outlet of the corrosion chamber was used to study the reaction of H{sub 2}S with zinc metal during the first 24 h. Four-week exposures were also performed to study the corrosion rate and the corrosion products. The deposition of H{sub 2}S on zinc strongly depended on the relative humidity. In dry air H{sub 2}S deposition was limited to an uptake on the order of a monolayer. At 70 to 99% RH the initial deposition rate of H{sub 2}S was faster, and the deposition reached a steady state after 15 to 20 h of exposure. Analysis of the H{sub 2}S evolved from the samples when treated with acid showed 95 {+-} 5% of the H{sub 2}S deposited on zinc to be present in sulfide form. X-ray photoelectron spectroscopy and ion chromatographic analysis supported this finding, small amounts of sulfate being detected besides sulfide. After a 4 week exposure to 410 ppb H{sub 2}S at 95% RH, zinc blende (sphalerite) (ZnS) was identified by grazing angle X-ray diffraction. It was concluded that the zinc sulfide film grows by bulk diffusion of ions. The rate of zinc sulfidation was independent of H{sub 2}S concentration between 25 and 780 ppb.

Svensson, J.E.; Johansson, L.G. [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Inorganic Chemistry]|[Univ. of Goeteborg (Sweden)

1995-05-01

89

Volatilization of hydrogen sulfide from a quiescent surface.  

PubMed

Air-water mass transfer of hydrogen sulfide from a shallow tank with a quiescent surface under the influence of weak wind stress on the water surface was studied numerically using a two-dimensional model. The flow field in the tank was investigated using a computational code based on a finite volume, which is used to numerically solve momentum, mass and continuity conservation equations. The results show that water phase flow field is strongly dependent on the wind-induced surface velocity and the aspect ratio of the tank. Based on the numerical study, the liquid-side mass transfer coefficient is correlated with Reynolds number (R(e)), tank aspect ratio (AR) and Schmidt number (S(c)). Overall mass transfer coefficient (K(L)) values extend further downstream as the R(e) number increases. PMID:22925874

de Cassia Feroni, Rita; Santos, Jane Meri; Reis, Neyval Costa

2012-01-01

90

Fecal hydrogen sulfide production in ulcerative colitis  

Microsoft Academic Search

Objective: Sulfide, a product of sulfate-reducing bacteria, has been proposed to play an etiologic role in ulcerative colitis. Ulcerative colitis feces have increased numbers and activity of sulfate-reducing bacteria, but only modestly increased sulfide. However, fecal sulfide exists largely in the volatile, highly toxic H2S form that moves rapidly from feces to surrounding gas. Our aim was to quantify the

Jimmy Levine; Carol J. Ellis; Julie K. Furne; John Springfield; Michael D. Levitt

1998-01-01

91

Production and Physiological Effects of Hydrogen Sulfide.  

PubMed

Abstract Significance: Hydrogen sulfide (H2S) has been recognized as a physiological mediator with a variety of functions. It regulates synaptic transmission, vascular tone, inflammation, transcription, and angiogenesis; protects cells from oxidative stress and ischemia-reperfusion injury; and promotes healing of ulcers. Recent Advances: In addition to cystathionine ?-synthase and cystathionine ?-lyase, 3-mercaptopyruvate sulfurtransferase along with cysteine aminotransferase was recently demonstrated to produce H2S. Even in bacteria, H2S produced by these enzymes functions as a defense against antibiotics, suggesting that the cytoprotective effect of H2S is a universal defense mechanism in organisms from bacteria to mammals. Critical Issues: The functional form of H2S-undissociated H2S gas, dissociated HS ion, or some other form of sulfur-has not been identified. Future Directions: The regulation of H2S production by three enzymes may lead to the identification of the physiological signals that are required to release H2S. The identification of the physiological functions of other forms of sulfur may also help understand the biological significance of H2S. Antioxid. Redox Signal. 00, 000-000. PMID:23581969

Kimura, Hideo

2013-05-25

92

Hydrogen sulfide as a vasculoprotective factor.  

PubMed

Hydrogen sulfide is a novel mediator with the unique properties of a gasotransmitter and many and varied physiological effects. Included in these effects are a number of cardiovascular effects that are proving beneficial to vascular health. Specifically, H2S can elicit vasorelaxation, prevention of inflammation and leukocyte adhesion, anti-proliferative effects and anti-thrombotic effects. Additionally, H2S is a chemical reductant and nucleophile that is capable of inhibiting the production of reactive oxygen species, scavenging and neutralising reactive oxygen species and boosting the efficacy of endogenous anti-oxidant molecules. These result in resistance to oxidative stress, protection of vascular endothelial function and maintenance of blood flow and organ perfusion. H2S has been shown to be protective in hypertension, atherosclerosis and under conditions of vascular oxidative stress, and deficiency of endogenous H2S production is linked to cardiovascular disease states. Taken together, these effects suggest that H2S has a physiological role as a vasculoprotective factor and that exogenous H2S donors may be useful therapeutic agents. This review article will discuss the vascular effects and anti-oxidant properties of H2S as well as examine the protective role of H2S in some important vascular disease states. PMID:23628084

Streeter, Eloise; Ng, Hooi H; Hart, Joanne L

2013-04-29

93

Hydrogen sulfide as a vasculoprotective factor  

PubMed Central

Hydrogen sulfide is a novel mediator with the unique properties of a gasotransmitter and many and varied physiological effects. Included in these effects are a number of cardiovascular effects that are proving beneficial to vascular health. Specifically, H2S can elicit vasorelaxation, prevention of inflammation and leukocyte adhesion, anti-proliferative effects and anti-thrombotic effects. Additionally, H2S is a chemical reductant and nucleophile that is capable of inhibiting the production of reactive oxygen species, scavenging and neutralising reactive oxygen species and boosting the efficacy of endogenous anti-oxidant molecules. These result in resistance to oxidative stress, protection of vascular endothelial function and maintenance of blood flow and organ perfusion. H2S has been shown to be protective in hypertension, atherosclerosis and under conditions of vascular oxidative stress, and deficiency of endogenous H2S production is linked to cardiovascular disease states. Taken together, these effects suggest that H2S has a physiological role as a vasculoprotective factor and that exogenous H2S donors may be useful therapeutic agents. This review article will discuss the vascular effects and anti-oxidant properties of H2S as well as examine the protective role of H2S in some important vascular disease states.

2013-01-01

94

Hydrogen sulfide and hemeproteins: knowledge and mysteries.  

PubMed

Historically, hydrogen sulfide (H(2)S) has been regarded as a poisonous gas, with a wide spectrum of toxic effects. However, like ·NO and CO, H(2)S is now referred to as a signaling gas involved in numerous physiological processes. The list of reports highlighting the physiological effects of H(2)S is rapidly expanding and several drug candidates are now being developed. As with ·NO and CO, not a single H(2)S target responsible for all the biological effects has been found till now. Nevertheless, it has been suggested that H(2)S can bind to hemeproteins, inducing different responses that can mediate its effects. For instance, the interaction of H(2)S with cytochrome c oxidase has been associated with the activation of the ATP-sensitive potassium channels, regulating muscle relaxation. Inhibition of cytochrome c oxidase by H(2)S has also been related to inducing a hibernation-like state. Although H(2)S might induce these effects by interacting with hemeproteins, the mechanisms underlying these interactions are obscure. Therefore, in this review we discuss the current state of knowledge about the interaction of H(2)S with vertebrate and invertebrate hemeproteins and postulate a generalized mechanism. Our goal is to stimulate further research aimed at evaluating plausible mechanisms that explain H(2)S reactivity with hemeproteins. PMID:21050142

Pietri, Ruth; Román-Morales, Elddie; López-Garriga, Juan

2011-04-08

95

Protection by DIGAZFEN-I hydrogen-sulfide corrosion inhibitor  

SciTech Connect

The performance of the new DIGAZFEN-I inhibitor for hydrogen sulfide corrosion in saline-hydrocarbon media, including the components (pyridine bases and fatty-acid aminoethers), was tested. Inhibition was determined gravimetrically on steel St3 in 3% NaCl solution and A-72 gasoline containing 1.5-2 g/liter hydrogen sulfide. Hydrogenation was determined indirectly from the plasticity changes in U9A steel strip specimens which were subsequently tested to failure. In parallel, potentiostatic measurements were made in 3% NaCl saturated with hydrogen sulfide with Armco iron. The inhibitor increased the hydrogen overvoltage and reduced the dissolution current while it also retarded both the anodic and cathodic processes.

Voloshin, V.F.; Golosova, O.P.; Mazalevskaya, L.A.; Bakumenko, V.S.; Sheinkman, A.K.

1988-07-01

96

Hydrogen sulfide dissociation in ozonizer discharges and operation of ozonizers at elevated temperatures  

Microsoft Academic Search

A high-temperature ozonizer device has been developed to stud v the conversion of hydrogen sulfide (H2S) into elemental sulfur and hydrogen. To allow for continuous operation, the process must be carried out at temperatures high enough to remove the sulfur in the liquid (=156°C) or in the vapor state (>435°C). A double quartz wall ozonizer which tolerates the high electrical

I. Traus; H. Suhr

1992-01-01

97

Aliphatic Tertiary Diamines as Film-Forming Inhibitors of Hydrogen Sulfide Corrosion  

Microsoft Academic Search

Aliphatic tertiary diamine (ATD) was synthesized and tested by gravimetric and electrochemical methods as a film-forming inhibitor of hydrogen sulfide corrosion. Both H2S-induced general corrosion in the vapor (80°C) and liquid (20 ± 2°C) phases and hydrogenation are inhibited by ATD more effectively than by aliphatic tertiary amines and commercial corrosion inhibitors. The data obtained were confirmed by comparative autoclave

S. A. Murav'eva; V. G. Mel'nikov; V. V. Egorov

2003-01-01

98

Carbonyl sulfide hydrolysis as a source of hydrogen sulfide in open ocean seawater  

Microsoft Academic Search

Two independent lines of evidence suggest that the hydrogen sulfides (H2S, SH-, S2-) are present in open surface seawater at pico to nanomolar levels. 1) Such concentrations are calculated for a chemical steady state involving carbonyl sulfide hydrolysis as source, followed by oxidative removal. 2) Although it is not yet certain that measurements of gaseous H2S over the open ocean

Scott Elliott; Eric Lu; F. Sherwood Rowland

1987-01-01

99

Plasma-chemical conversion of hydrogen sulfide into hydrogen and sulfur.  

National Technical Information Service (NTIS)

A waste-treatment process that recovers both hydrogen and sulfur from hydrogen-sulfide-contaminated industrial wastes is being developed to replace the Claus technology, which recovers only sulfur. The proposed process is based on research reported in the...

J. B. L. Harkness R. D. Doctor E. J. Daniels

1993-01-01

100

Hydrogen sulfide induces oxidative damage to RNA and DNA in a sulfide-tolerant marine invertebrate.  

PubMed

Hydrogen sulfide acts as an environmental toxin across a range of concentrations and as a cellular signaling molecule at very low concentrations. Despite its toxicity, many animals, including the mudflat polychaete Glycera dibranchiata, are periodically or continuously exposed to sulfide in their environment. We tested the hypothesis that a broad range of ecologically relevant sulfide concentrations induces oxidative stress and oxidative damage to RNA and DNA in G. dibranchiata. Coelomocytes exposed in vitro to sulfide (0-3 mmol L(-1) for 1 h) showed dose-dependent increases in oxidative stress (as 2',7'-dichlorofluorescein fluorescence) and superoxide production (as dihydroethidine fluorescence). Coelomocytes exposed in vitro to sulfide (up to 0.73 mmol L(-1) for 2 h) also acquired increased oxidative damage to RNA (detected as 8-oxo-7,8-dihydroguanosine) and DNA (detected as 8-oxo-7,8-dihydro-2'-deoxyguanosine). Worms exposed in vivo to sulfide (0-10 mmol L(-1) for 24 h) acquired elevated oxidative damage to RNA and DNA in both coelomocytes and body wall tissue. While the consequences of RNA and DNA oxidative damage are poorly understood, oxidatively damaged deoxyguanosine bases preferentially bind thymine, causing G-T transversions and potentially causing heritable point mutations. This suggests that sulfide can be an environmental mutagen in sulfide-tolerant invertebrates. PMID:19327040

Joyner-Matos, Joanna; Predmore, Benjamin L; Stein, Jenny R; Leeuwenburgh, Christiaan; Julian, David

101

Hydrogen Sulfide and the Pathogenesis of Atherosclerosis.  

PubMed

Abstract Significance: Stigmatized as a toxic environmental pollutant for centuries, hydrogen sulfide (H2S) has gained recognition over the last decade as an important gasotransmitter that functions in physiological and pathophysiological conditions, such as atherosclerosis. Recent Advances: Atherosclerosis is a common disease that stems from the buildup of fatty/cholesterol plaques on the endothelial cells of arteries. The deposits mitigate thickening and stiffening of arterial tissue, which contributes to concomitant systemic or localized vascular disorders. Recently, it has been recognized that H2S plays an anti-atherosclerotic role, and its deficiency leads to early development and progression of atherosclerosis. This review article presents multiple lines of evidence for the protective effects of H2S against the development of atherosclerosis. Also highlighted are the characterization of altered metabolism of H2S in the development of atherosclerosis, underlying molecular and cellular mechanisms, and potential therapeutic intervention based on H2S supplementation for atherosclerosis management. Critical Issues: Although a protective role of H2S against atherosclerosis has emerged, controversy remains regarding the mechanisms underlying H2S-induced endothelial cell proliferation and angiogenesis as well as its anti-inflammatory properties. The therapeutic value of H2S to this pathophysiological condition has not been tested clinically but, nonetheless, it shows tremendous promise. Future Directions: The efficiency and safety profile of H2S-based therapeutic approaches should be refined, and the mechanisms by which H2S exerts its beneficial effects should be elucidated to develop more specific and potent therapeutic strategies to treat atherosclerosis. Whether the therapeutic effects of H2S in animal studies are transferable to clinical studies merits future investigation. Antioxid. Redox Signal. 00, 000-000. PMID:23582095

Mani, Sarathi; Untereiner, Ashley; Wu, Lingyun; Wang, Rui

2013-05-21

102

Hydrogen Sulfide in Biochemistry and Medicine  

PubMed Central

Abstract Significance: An abundance of experimental evidence suggests that hydrogen sulfide (H2S) plays a prominent role in physiology and pathophysiology. Many targets exist for H2S therapy. The molecular targets of H2S include proteins, enzymes, transcription factors, and membrane ion channels. Recent Advances: Novel H2S precursors are being synthesized and discovered that are capable of releasing H2S in a slow and sustained manner. This presents a novel and advantageous approach to H2S therapy for treatment of chronic conditions associated with a decline in endogenous H2S, such as diabetes and cardiovascular disease. Critical Issues: While H2S is cytoprotective at physiological concentrations, it is not universally cytoprotective, as it appears to have pro-apoptotic actions in cancer cells and is well known to be toxic at supraphysiological concentrations. Many of the pleiotropic effects of H2S on health are associated with the inhibition of inflammation and upregulation of prosurvival pathways. The powerful anti-inflammatory, cytoprotective, immunomodulating, and trophic effects of H2S on the vast majority of normal cells seem to be mediated mainly by its actions as an extremely versatile direct and indirect antioxidant and free radical scavenger. While the overall effects of H2S on transformed (i.e., malignant) cells can be characterized as pro-oxidant and pro-apoptotic, they contrast sharply with the cytoprotective effects on most normal cells. Future Directions: H2S has become a molecule of great interest, and several slow-releasing H2S prodrugs are currently under development. We believe that additional agents regulating H2S bioavailability will be developed during the next 10 years. Antioxid. Redox Signal. 17, 119–140.

Predmore, Benjamin Lee; Lefer, David Joseph

2012-01-01

103

Plasma-chemical conversion of hydrogen sulfide into hydrogen and sulfur  

Microsoft Academic Search

A waste-treatment process that recovers both hydrogen and sulfur from hydrogen-sulfide-contaminated industrial wastes is being developed to replace the Claus technology, which recovers only sulfur. The proposed process is based on research reported in the Soviet technical literature and uses microwave (or radio-frequency) energy to initiate plasma-chemical reactions that dissociate hydrogen sulfide into elemental hydrogen and sulfur. In the plasma-chemical

J. B. L. Harkness; R. D; E. J. Daniels

1993-01-01

104

Endogenous Production of Hydrogen Sulfide in Isolated Bovine Eye  

Microsoft Academic Search

Hydrogen sulfide (H2S) is a novel gasotransmitter with physiological and pathological functions in vascular homeostasis, cardiovascular system\\u000a and central nervous system. In the present study, we determined the endogenous levels of H2S in various tissues of the bovine eye. We also examined the basal levels of H2S in response to donors (sodium hydrosulfide, NaHS and sodium sulfide, Na2S), substrate (l-cysteine),

Madhura Kulkarni; Ya Fatou Njie-Mbye; Ikechukwu Okpobiri; Min Zhao; Catherine A. Opere; Sunny E. Ohia

105

Determination of hydrogen sulfide in fermentation broths containing SO 2 .  

PubMed

A procedure for the determination of hydrogen sulfide in fermentation broths containing up to 100 mug of SO(2) per ml is described. The method involves the sparging of H(2)S from the broth into a cadmium hydroxide absorption solution, the formation of methylene blue from the absorbed sulfide, and the measuring of this color spectrophotometrically. The use of cadmium hydroxide instead of zinc acetate, the common absorbent, substantially reduced the interference of SO(2) with the analysis. PMID:5111300

Acree, T E; Sonoff, E P; Splittstoesser, D F

1971-07-01

106

Process for the production of hydrogen and carbonyl sulfide from hydrogen sulfide and carbon monoxide using a multi-metal oxide/sulfide catalyst  

SciTech Connect

Hydrogen and carbonyl sulfide are produced by a process comprising contacting gaseous hydrogen sulfide with gaseous carbon monoxide in the presence of a catalytic composition containing an oxide and/or sulfide of at least one of molybdenum, tungsten, iron, chromium and vanadium in combination with at least one promoter metal, e.g. a catalyst of the formula Cs Cu /SUB 0.2/ Zn /SUB 0.5/ Mn /SUB 0.5/ Sn /SUB 2.4/ Mo O /SUB x/ S /SUB y/ .

Jevnikar, M. G.; Kuch, Ph. L.

1985-02-19

107

40 CFR 60.648 - Optional procedure for measuring hydrogen sulfide in acid gas-Tutwiler Procedure. 1  

Code of Federal Regulations, 2010 CFR

...Optional procedure for measuring hydrogen sulfide in acid gas-Tutwiler Procedure...Optional procedure for measuring hydrogen sulfide in acid gasâTutwiler Procedure...method consists of titrating hydrogen sulfide in a gas sample directly...

2010-07-01

108

Process for removing carbonyl-sulfide from liquid hydrocarbon feedstocks  

SciTech Connect

A process is described for removing carbonyl sulfide from a liquid olefinic hydrocarbon feedstock comprising: (a) passing the hydrocarbon feedstock over an absorbent material comprising zinc oxide and a promoter selected from the group consisting of alumina, silico-aluminas and any combination thereof wherein the promoter is present in amounts from about 3 to about 15 percent by weight of the absorbent material; and (b) recovering a liquid olefinic hydrocarbon stream having a substantially reduced carbonyl sulfide content.

Debras, G.L.G.; DeClippeleir, G.E.M.J.; Cahen, R.M.

1986-09-23

109

The role of sulfur trapped in micropores in the catalytic partial oxidation of hydrogen sulfide with oxygen  

Microsoft Academic Search

The catalytic oxidation of hydrogen sulfide into sulfur with molecular oxygen has been studied in the temperature range 130–200 °C. Active carbon, molecular sieve 13X and liquid sulfur were used as catalysts. Sulfur is adsorbed in the micropores (3 < r < 40 Å) of the catalysts. Experiments with a surface of liquid sulfur demonstrated that sulfur is a catalyst

M. Steijns; P. Mars

1974-01-01

110

A generalized correlation for the Peng-Robinson interaction coefficients for paraffin?hydrogen sulfide binary systems  

Microsoft Academic Search

A review of the literature revealed a paucity of data for the vapor-liquid equilibrium of systems containing hydrogen sulfide and paraffin hydrocarbons. In order to estimate the vapor-liquid equilibrium of systems for which no data exist, a correlation of the interaction parameter for the Peng-Robinson equation of state is provided.

John J Carroll; Alan E Mather

1995-01-01

111

Hydrogen sulfide-mediated myocardial pre- and post-conditioning  

PubMed Central

Coronary artery disease is a major cause of morbidity and mortality in the Western world. Acute myocardial infarction, resulting from coronary artery atherosclerosis, is a serious and often fatal consequence of coronary artery disease, resulting in cell death in the myocardium. Pre- and post-conditioning of the myocardium are two treatment strategies that reduce the amount of cell death significantly. Hydrogen sulfide has recently been identified as a potent cardioprotective signaling molecule, which is a highly effective pre- and post-conditioning agent. The cardioprotective signaling pathways involved in hydrogen sulfide-based pre- and post-conditioning will be explored in this article.

Predmore, Benjamin L; Lefer, David J

2011-01-01

112

Hydrogen Sulfide as a Regulator of Systemic Functions in Vertebrates  

Microsoft Academic Search

This review deals with new published data and also with our own findings related to the physiological and pathological effects\\u000a of hydrogen sulfide (H2S), a gasotransmitter, which has recently attracted intense attention. In the organism, hydrogen sulfide is synthesized from\\u000a cysteine with the involvement of pyridoxal-5?-phosphate-dependent enzymes, cystathionine-?-synthase (CBS) or cystathionine-?-lyase\\u000a (CSE). Under the action of H2S, ATP-dependent potassium channels

A. A. Varaksin; E. V. Puschina

2011-01-01

113

The body wall of Halicryptus spinulosus (Priapulida) — ultrastructure and changes induced by hydrogen sulfide  

Microsoft Academic Search

Halicryptus spinulosus (Priapulida) is extraordinarily resistant to hydrogen sulfide. As described previously, the body wall of specimens from oxic and from hydrogen sulfide-contaminated habitats differs strikingly in colour. In the present paper the ultrastructure of the body wall of specimens kept under oxic conditions is described. These findings serve as a reference for changes induced by exposure to hydrogen sulfide.

Hans Heinrich Janssen; Rolf Oeschger

1992-01-01

114

New inhibitors of hydrogen sulfide corrosion for gas-turbine oils  

Microsoft Academic Search

Along with the development of deposits of natural gas containing hydrogen sulfide, it has become extremely urgent to provide corrosion protection for the equipment in gas pumping stations and gas processing plants. In the presence of moisture and hydrogen sulfide, the rates of overall and chemical corrosion are several times higher; and hydrogen embrittlement and sulfide cracking of steel may

V. A. Trofimov; V. G. Spirkin; T. O. Ablyazova; A. A. Bocharov

1997-01-01

115

Removing hydrogen sulfide from geothermal gases: hypochlorite process reduces hydrogen sulfide emissions to acceptable levels. NTIS tech note  

SciTech Connect

This citation summarizes a one-page announcement of technology available for utilization. A hypochlorite process has been proposed as an alternative to other methods for the removal of hydrogen sulfide from the exhaust gases of geothermal powerplants. An electrolytically-generated sodium hypochlorite solution converts the hydrogen sulfide to water, salt, and sulfur. The hypochlorite process appears to be less expensive than competing processes for most of the cases studied. ...FOR ADDITIONAL INFORMATION: Detailed information about the technology described may be obtained by ordering the NTIS report, order number: DOE/ER/1092-T7, price code: PC A03.

Not Available

1981-10-01

116

Assessment of effects of chronic hydrogen sulfide poisoning on cytochrome p450 isoforms activity of rats by cocktail approach.  

PubMed

Hydrogen sulfide (H2S) is one of the neurotoxic gases with suffocating and irritating. Its main target organs of toxic effects are the central nervous system and respiratory system. Cocktail method was used to evaluate the influence of chronic hydrogen sulfide poisoning on the activities of cytochrome P450 (CYP450) isoforms CYP1A2, CYP2C9, CYP2B6 and CYP2D6, which were reflected by the changes of pharmacokinetic parameters of 4 specific probe drugs phenacetin, tolbutamide bupropion and metroprolol, respectively. The experimental rats were randomly divided into two groups, control group and chronic hydrogen sulfide poisoning group. The chronic hydrogen sulfide poisoning group rats were inhaled 20?ppm for 1?h twice a day for 40?d. The mixture of 4 probes was given to rats through sublingual veins and the blood samples were obtained at a series of time-points through the caudal vein. The concentrations of probe drugs in rat plasma were measured by liquid chromatography-mass spectrometry (LC-MS). In the experiment for chronic hydrogen sulfide poisoning and control group, there was a statistically significant difference in the area under the plasma concentration-time curve from zero to infinity (AUC0-?), plasma clearance (CL) and maximum plasma concentration (Cmax) for phenacetin and bupropion, while there was no statistical pharmacokinetics difference for tolbutamide and metoprolol. Chronic hydrogen sulfide poisoning could induce the activity of CYP1A2 and CYP2B6 of rats. PMID:24088256

Wang, Xianqin; Chen, Xiaole; Chen, Mengchun; Hu, Guoxin; Ma, Jianshe; Pan, Jianchun; Hu, Lufeng; Lin, Guanyang

2013-01-01

117

Liquid Hydrogen: Target, Detector  

SciTech Connect

In 1952 D. Glaser demonstrated that a radioactive source's radiation could boil 135 deg. C superheated-diethyl ether in a 3-mm O glass vessel and recorded bubble track growth on high-speed film in a 2-cm3 chamber. This Bubble Chamber (BC) promised improved particle track time and spatial resolution and cycling rate. Hildebrand and Nagle, U of Chicago, reported Liquid Hydrogen minimum ionizing particle boiling in August 1953. John Wood created the 3.7-cm O Liquid Hydrogen BC at LBL in January 1954. By 1959 the Lawrence Berkley Laboratory (LBL) Alvarez group's '72-inch' BC had tracks in liquid hydrogen. Within 10 years bubble chamber volumes increased by a factor of a million and spread to every laboratory with a substantial high-energy physics program. The BC, particle accelerators and special separated particle beams created a new era of High Energy Physics (HEP) experimentation. The BC became the largest most complex cryogenic installation at the world's HEP laboratories for decades. The invention and worldwide development, deployment and characteristics of these cryogenic dynamic target/detectors and related hydrogen targets are described.

Mulholland, G.T. [Applied Cryogenics Technology, Ovilla TX 75154 (United States); Harigel, G.G. [CERN, European Organization for Nuclear Research, 1211 Geneva 23 (Switzerland)

2004-06-23

118

A Thermodynamic Property Model for Fluid Phase Hydrogen Sulfide  

Microsoft Academic Search

A Helmholtz free energy equation of state for the fluid phase of hydrogen sulfide has been developed as a function of reduced temperature and density with 23 terms on the basis of selected measurements of pressure–density–temperature (P, ?, T), isobaric heat capacity, and saturation properties. Based on a comparison with available experimental data, it is recognized that the model represents

N. Sakoda; M. Uematsu

2004-01-01

119

Hydrogen sulfide dissociation in a barrier discharge plasma  

Microsoft Academic Search

The authors studied the decomposition of hydrogen sulfide in a barrier discharge. The choice of a barrier discharge was not made by chance. It possesses the following properties resulting in its having advantage over other types of discharges. (1) Use of a barrier discharge permits one to obtain superequilibrium atom concentrations for a given temperature owing to the nonisothermic plasma

F. A. Teimurova; A. M. Rasulov; N. T. Klimov

1992-01-01

120

Health Assessment Document for Hydrogen Sulfide, Review Draft.  

National Technical Information Service (NTIS)

Hydrogen sulfide is a highly toxic gas which is immediately lethal in concentrations greater than 2000 ppm. The toxic end-point is due to anoxia to brain and heart tissues which results from its interaction with the celluar enzyme cytochrome oxidase. Inhi...

H. M. Ammann F. Bradow D. Fennell R. Griffin B. Kearney

1986-01-01

121

Kinetics and mechanism of hydrogen sulfide oxidation in sea water  

SciTech Connect

This article provides a comprehensive chemical investigation on the oxidation of acid rain-transported hydrogen sulfides in sea water and on the environmental consequences of their oxidation products. Biochemical and microbiological mechanisms are discussed in detail. Implications and effects for the world's oceans in general are discussed and special emphasis is given to the Black Sea.

Leonov, A.V.; Aizatullin, T.A.

1987-11-01

122

DETERMINATION OF HYDROGEN SULFIDE IN REFINERY FUEL GASES  

EPA Science Inventory

Several widely employed test methods for the iodimetric measurement of hydrogen sulfide in refinery fuel gases are shown to suffer from serious thiol interferences. An absorbing solution consisting of 0.16 M cadmium sulfate/sulfuric acid at pH 3.0 is shown to be effective for the...

123

Novel Hydrogen Sulfide Sensors for Portable Monitors, Phase 1.  

National Technical Information Service (NTIS)

During this SBIR Phase I project, Nanomaterials Research (NRLLC) successfully demonstrated a new type of sensor device for detecting hydrogen sulfide (H2S). This gas is extremely toxic at low concentrations, and workplace exposure is common in a number of...

C. J. Kostelecky D. J. Deininger E. J. Benstock K. Womer M. W. Hooker S. A. Hooker S. S. Williams

2002-01-01

124

Novel Hydrogen Sulfide Sensors for Portable Monitors, Phase 2.  

National Technical Information Service (NTIS)

The primary objective of this SBIR Phase II project was to design, develop, and demonstrate a better sensor technology for detecting the presence of hydrogen sulfide (H2S), a particularly hazardous gas species. Because of the potential for adverse health ...

S. Williams

2006-01-01

125

Characterizing ammonia and hydrogen sulfide emissions from a swine waste treatment lagoon in North Carolina  

Microsoft Academic Search

Emissions of atmospheric ammonia–nitrogen (NH3-N, where NH3-N=(14\\/17)NH3) and hydrogen sulfide (H2S) from a commercial anaerobic swine waste treatment lagoon (17,150m2 at normal liquid level) were measured over a 1-year period. Continuous simultaneous measurements were made at the lagoon using a dynamic flow-through chamber system for ?1 week during four seasons, October–November 2004 (fall), February 2005 (winter), April 2005 (spring), and

Jessica Blunden; Viney P. Aneja

2008-01-01

126

Determination of hydrogen sulfide and volatile thiols in air samples by mercury probe derivatization coupled with liquid chromatography-atomic fluorescence spectrometry.  

PubMed

A new procedure is proposed for the sampling and storage of hydrogen sulphide (H2S) and volatile thiols (methanethiol or methyl mercaptan, ethanethiol and propanethiol) for their determination by liquid chromatography. The sampling procedure is based on the trapping/pre-concentration of the analytes in alkaline aqueous solution containing an organic mercurial probe p-hydroxymercurybenzoate, HO-Hg-C6H4-COO- (PHMB), where they are derivatized to stable PHMB complexes based on mercury-sulfur covalent bonds. PHMB complexes are separated on a C18 reverse phase column, allowing their determination by liquid chromatography coupled with sequential non-selective UV-vis (DAD) and mercury specific (chemical vapor generation atomic fluorescence spectrometry, CVGAFS) on-line detectors. PHMB complexes, S(PHMB)2CH3S-PHMB, C2H5S-PHMB and C3H7S-PHMB, are stable alt least for 12 h at room temperature and for 3 months if stored frozen (-20 degrees C). The best analytical figures of merits in the optimized conditions were obtained by CVGAFS detection, with detection limits (LODc) of 9.7 microg L(-1) for H2S, 13.7 microg L(-1) for CH(3)SH, 17.7 microg L(-1) for C2H5SH and 21.7 microg L(-1) for C3H7SH in the trapping solution in form of RS-PHMB complexes, the relative standard deviation (R.S.D.) ranging between 1.0 and 1.5%, and a linear dynamic range (LDR) between 10 and 9700 microg L(-1). Conventional UV absorbance detectors tuned at 254 nm can be employed as well with comparable R.S.D. and LDR, but with LODc one order of magnitude higher than AFS detector and lower specificity. The sampling procedure followed by LC-DAD-CVGAFS analysis has been validated, as example, for H2S determination by a certified gas permeation tube as a source of 3.071+/-0.154 microg min(-1) of H2S, giving a recovery of 99.8+/-7% and it has been applied to the determination of sulfur compounds in real gas samples (biogas and the air of a plant for fractional distillation of crude oil). PMID:17723725

Bramanti, Emilia; D'Ulivo, Lucia; Lomonte, Cristina; Onor, Massimo; Zamboni, Roberto; Raspi, Giorgio; D'Ulivo, Alessandro

2006-07-08

127

Nitrite as an antidote for acute hydrogen sulfide intoxication  

SciTech Connect

The detoxification of hydrogen sulfide (H/sub 2/S) by a heme catalyzed oxidation was examined as part of an on-going study of H/sub 2/S toxicity. Interlocking O/sub 2/ absorption and sulfide depletion data indicate that both oxyhemoglobin and methemoglobin are effective catalytic agents. Although the latter is more efficacious, the life time of excess sulfide in the presence of oxygen and either of the above is of the order of minutes. It has also been established that the formation of methemoglobin following nitrite administration occurs preferentially under oxygen poor conditions. Under an atmospheric or oxygen enriched environment, which favors sulfide depletion, the nitrite retards sulfide oxidation. Thus nitrite as an antidote for acute H/sub 2/S intoxication can only be effective within the first few minutes after the exposure, at which time resuscitation and/or ventilation of the victim is likely to produce conditions in which the nitrite actually slows sulfide removal.

Beck, J.F.; Bradbury, C.M.; Connors, A.J.; Donini, J.C.

1981-11-01

128

Solubility and Permeation of Hydrogen Sulfide in Lipid Membranes  

PubMed Central

Hydrogen sulfide (H2S) is mainly known for its toxicity but has recently been shown to be produced endogenously in mammalian tissues and to be associated with physiological regulatory functions. To better understand the role of biomembranes in modulating its biological distribution and effects; we measured the partition coefficient of H2S in models of biological membranes. The partition coefficients were found to be 2.1±0.2, 1.9±0.5 and 2.0±0.6 in n-octanol, hexane and dilauroylphosphatidylcholine liposome membranes relative to water, respectively (25°C). This two-fold higher concentration of H2S in the membrane translates into a rapid membrane permeability, Pm?=?3 cm s?1. We used a mathematical model in three dimensions to gain insight into the diffusion of total sulfide in tissues. This model shows that the sphere of action of sulfide produced by a single cell expands to involve more than 200 neighboring cells, and that the resistance imposed by lipid membranes has a significant effect on the diffusional spread of sulfide at pH 7.4, increasing local concentrations. These results support the role of hydrogen sulfide as a paracrine signaling molecule and reveal advantageous pharmacokinetic properties for its therapeutic applications.

Cuevasanta, Ernesto; Denicola, Ana; Alvarez, Beatriz; Moller, Matias N.

2012-01-01

129

Biology and therapeutic potential of hydrogen sulfide and hydrogen sulfide-releasing chimeras.  

PubMed

Hydrogen sulfide, H2S, is a colorless gas with a strong odor that until recently was only considered to be a toxic environmental pollutant with little or no physiological significance. However, the past few years have demonstrated its role in many biological systems and it is becoming increasingly clear that H2S is likely to join nitric oxide (NO) and carbon monoxide (CO) as a major player in mammalian biology. In this review, we have provided an overview of the chemistry and biology of H2S and have summarized the chemistry and biological activity of some natural and synthetic H2S-donating compounds. The naturally occurring compounds discussed include, garlic, sulforaphane, erucin, and iberin. The synthetic H2S donors reviewed include, GYY4137; cysteine analogs; S-propyl cysteine, S-allyl cysteine, S-propargyl cysteine, and N-acetyl cysteine. Dithiolethione and its NSAID and other chimeras such as, L-DOPA, sildenafil, aspirin, diclofenac, naproxen, ibuprofen, indomethacin, and mesalamine have also been reviewed in detail. The newly reported NOSH-aspirin that releases both NO and H2S has also been discussed. PMID:23103569

Kashfi, Khosrow; Olson, Kenneth R

2012-10-24

130

Activity enhancement of mesoporous silicate FSM-16 by metal ion-exchange and sulfiding with hydrogen sulfide for acid-catalyzed reactions  

Microsoft Academic Search

The modification of mesoporous silicate FSM-16 by metal ion-exchange and sulfiding with hydrogen sulfide was studied through the isomerization of 1-butène, cis-2-butene and cyclopropane. It was revealed that the catalytic activities of MeFSM-16 were remarkably enhanced by sulfiding with hydrogen sulfide due to the formation of new Brönsted acid sites

M. Sugioka; L Andalaluna; J. K. A. Dapaah

2000-01-01

131

The emerging roles of hydrogen sulfide in the gastrointestinal tract and liver.  

PubMed

Hydrogen sulfide, like nitric oxide, was best known as a toxic pollutant before becoming recognized as a key regulator of several physiologic processes. In recent years, evidence has accumulated to suggest important roles for hydrogen sulfide as a mediator of several aspects of gastrointestinal and liver function. Moreover, alterations in hydrogen sulfide production could contribute to disorders of the gastrointestinal tract and liver. For example, nonsteroidal anti-inflammatory drugs can reduce production of hydrogen sulfide in the stomach, and this has been shown to contribute to the generation of mucosal injury. Hydrogen sulfide has also been shown to play a key role in modulation of visceral hyperalgesia. Inhibitors of hydrogen sulfide synthesis and drugs that can generate safe levels of hydrogen sulfide in vivo have been developed and are permitting interventional studies in experimental models and, in the near future, humans. PMID:16831608

Fiorucci, Stefano; Distrutti, Eleonora; Cirino, Giuseppe; Wallace, John L

2006-03-06

132

Surface analysis of inhibitor films formed in hydrogen sulfide medium  

SciTech Connect

Steel samples exposed to a 5% sodium chloride solution containing 0.5% acetic acid saturated with hydrogen sulfide, with and without imidazole as an inhibitor, were analyzed by X-ray photoelectron spectroscopy and secondary ion mass spectrometry. The metal surface was covered initially by a layer of iron sulfide or oxide. This layer, in turn, was covered by layers in which Fe was bonded to bisulfide and C{sub 3}H{sub 4}N{sub 2} groups. Corrosion protection probably resulted from the iron sulfide or oxide formed on the metal which was prevented from going into solution and recrystallization by the thin upper layer containing C{sub 3}H{sub 4}N{sub 2}.

Sastri, V.S.; Elboujdaini, M.; Brown, J.R. [CANMET, Ottawa, Ontario (Canada); Perumareddi, J.R. [Florida Atlantic Univ., Boca Raton, FL (United States). Chemistry Dept.

1996-06-01

133

MODELING OF SYNGAS REACTIONS AND HYDROGEN GENERATION OVER SULFIDES  

SciTech Connect

The objective of the research is to analyze pathways of reactions of hydrogen with oxides of carbon over sulfides, and to predict which characteristics of the sulfide catalyst (nature of metal, defect structure) give rise to the lowest barriers toward oxygenated hydrocarbon product. Reversal of these pathways entails the generation of hydrogen, which is also proposed for study. During this study, adsorption reactions of H atoms and H{sub 2} molecules with MoS{sub 2}, both in molecular and solid form, have been modeled using high-level density functional theory. The relative stabilities of pure MoS{sub 2} edges were calculated and small clusters exhibiting properties of the edges were modeled. The results were finalized and published in the journal ''Surface Science''. Hydrogen adsorption energies on both the edges and the clusters were calculated, and the thermodynamics of hydrogen adsorption on both systems were evaluated. The adsorption locations and vibrational frequencies were also determined. These additional results were published in a second paper in ''Surface Science''. Most recently, the bonding and effect of alkali and transition metal ions was investigated on the MoS{sub 2} clusters. Potassium atoms bind to the clusters and increase the binding of hydrogen to the clusters while reducing the activation barriers for hydrogen adsorption. Silver attaches to the Mo7S14 cluster and donates its odd electron to the nearby Mo atoms and should have a similar effect to hydrogen as potassium does.

Kamil Klier; Jeffery A. Spirko; Michael L. Neiman

2004-10-01

134

Transition metal sulfide hydrogen evolution catalysts for hydrobromic acid electrolysis.  

PubMed

Mixed metal sulfides containing combinations of W, Fe, Mo, Ni, and Ru were synthesized and screened for activity and stability for the hydrogen evolution reaction (HER) in aqueous hydrobromic acid (HBr). Co- and Ni-substituted RuS(2) were identified as potentially active HER electrocatalysts by high-throughput screening (HTS), and the specific compositions Co(0.4)Ru(0.6)S(2) and Ni(0.6)Ru(0.4)S(2) were identified by optimization. Hydrogen evolution activity of Co(0.4)Ru(0.6)S(2) in HBr is greater than RuS(2) or CoS(2) and comparable to Pt and commercial Rh(x)S(y). Structural and morphological characterizations of the Co-substituted RuS(2) suggest that the nanoparticulate solids are a homogeneous solid solution with a pyrite crystal structure. No phase separation is detected for Co substitutions below 30% by X-ray diffraction. In 0.5 M HBr electrolyte, the Co-Ru electrode material synthesized with 30% Co rapidly lost approximately 34% of the initial loading of Co; thereafter, it was observed to exhibit stable activity for HER with no further loss of Co. Density functional theory calculations indicate that the S(2)(2-) sites are the most important for HER and the presence of Co influences the S(2)(2-) sites such that the hydrogen binding energy at sufficiently high hydrogen coverage is decreased compared to ruthenium sulfide. Although showing high HER activity in a flow cell, the reverse reaction of hydrogen oxidation is slow on the RuS(2) catalysts tested when compared to platinum and rhodium sulfide, leaving rhodium sulfide as the only suitable tested material for a regenerative HBr cell due its stability compared to platinum. PMID:23205859

Ivanovskaya, Anna; Singh, Nirala; Liu, Ru-Fen; Kreutzer, Haley; Baltrusaitis, Jonas; Nguyen, Trung Van; Metiu, Horia; McFarland, Eric

2012-12-18

135

Simultaneous hydrogen sulfide abatement and production of acid for scale control and well stimulation  

Microsoft Academic Search

A process has been developed to flow geothermal vent gas, containing hydrogen sulfide, through a bed of halogen containing oxidizing agent granules. In the absence of significant moisture, hydrogen sulfide reacts with the oxidizing agent to yield elemental sulfur and hydrogen halide gas. The elemental sulfur deposits on the oxidizing agent particles, and the produced hydrogen halide gas is sparged

Darrell L. Gallup

136

Measurement and biological significance of the volatile sulfur compounds hydrogen sulfide, methanethiol and dimethyl sulfide in various biological matrices.  

PubMed

This review deals with the measurement of the volatile sulfur compounds hydrogen sulfide, methanethiol and dimethyl sulfide in various biological matrices of rats and humans (blood, serum, tissues, urine, breath, feces and flatus). Hydrogen sulfide and methanethiol both contain the active thiol (-SH) group and appear in the free gaseous form, in the acid-labile form and in the dithiothreitol-labile form. Dimethyl sulfide is a neutral molecule and exists only in the free form. The foul odor of these sulfur volatiles is a striking characteristic and plays a major role in bad breath, feces and flatus. Because sulfur is a biologically active element, the biological significance of the sulfur volatiles are also highlighted. Despite its highly toxic properties, hydrogen sulfide has been lately recommended to become the third gasotransmitter, next to nitric oxide and carbon monoxide, based on high concentration found in healthy tissues, such as blood and brain. However, there is much doubt about the reliability of the assay methods used. Many artifacts in the sulfide assays exist. The methods to detect the various forms of hydrogen sulfide are critically reviewed and compared with findings of our group. Recent findings that free gaseous hydrogen sulfide is absent in whole blood urged the need to revisit its role as a blood-borne signaling molecule. PMID:19505855

Tangerman, Albert

2009-05-21

137

Evaluation of the efficiency of corrosion inhibitors for pipe steels in hydrogen-sulfide-containing media  

Microsoft Academic Search

About one third of newly explored gas fields in the Ukraine contain at most 1 vol.% of hydrogen sulfide. For gas fields with relatively low contents of hydrogen sulfide, the application of materials with elevated resistance to hydrogen-sulfide stress-corrosion cracking (HSSC) and hydrogen-induced cracking leads to unreasonably high costs spent for the equipment of gas fields. At the same time,

R. M. Yurkevych

2009-01-01

138

Selective Medium for Hydrogen Sulfide Production by Salmonellae  

PubMed Central

Triple Sugar Iron Agar does not reveal hydrogen sulfide production by all Salmonella organisms nor does it permit clear-cut separation of those nonsalmonellae which produce H2S. Numerous media with varied combinations of nutrients, inhibitors, selective agents, pH levels, and metal salts were tested for H2S production of cultures of Salmonella, Citrobacter, Edwardsiella, Arizona, Proteus, Providencia, Klebsiella, and Enterobacter. An agar medium has been devised which promotes growth and H2S production (generally within 6 hr) by Salmonella, Arizona, and Edwardsiella but which inhibits hydrogen sulfide production or growth of all other gram-negative organisms tested (including Citrobacter) or inhibits both. The use of this medium should facilitate the selection and identification of Salmonella.

Padron, A. P.; Dockstader, W. B.

1972-01-01

139

Japanese experience of hydrogen sulfide: the suicide craze in 2008  

PubMed Central

Most of hydrogen sulfide poisoning has been reported as industrial accidents in Japan. However, since January 2008, a burgeoning of suicide attempts using homemade hydrogen sulfide gas has become evident. By April 2008, the fad escalated into a chain reaction nationwide. Mortality of the poisoning was very high. There were 220 cases of attempted gas suicides during the period of March 27 to June 15, killing 208. An introduction of new method of making the gas, transmitted through message boards on the internet, was blamed for this "outbreak". The new method entailed mixing bath additive and toilet detergent. The National Police Agency instructed internet providers to remove information that could be harmful. Of the victims of the fad in 2008, several cases were serious enough that family members were involved and died. Paramedics and caregivers were also injured secondarily by the gas. This fad has rapidly spread by internet communication, and can happen anywhere in the world.

2010-01-01

140

Modeling of Syngas Reactions and Hydrogen Generation Over Sulfides  

SciTech Connect

The objective of the research is to analyze pathways of reactions of hydrogen with oxides of carbon over sulfides, and to predict which characteristics of the sulfide catalyst (nature of metal, defect structure) give rise to the lowest barriers toward oxygenated hydrocarbon product. Reversal of these pathways entails the generation of hydrogen, which is also proposed for study. In this second year of study, high-level density functional theory was used to model the edge defect of MoS{sub 2} both with and without H atoms and H{sub 2} molecules absorbed on those edges. The structures and stabilities of the pure MoS{sub 2} edges were finalized and published. Several MoS{sub 2} cluster models were examined to provide insight into the behavior of the more complex edges. With that knowledge, the adsorption locations, energies, and vibrational frequencies of H adsorption were determined.

Kamil Klier; Jeffery A. Spirko; Michael L. Neiman

2003-09-17

141

Process for the production of hydrogen and carbonyl sulfide from hydrogen sulfide and carbon monoxide using a metal boride, nitride, carbide and/or silicide catalyst  

SciTech Connect

Hydrogen and carbonyl sulfide are produced by a process comprising contacting gaseous hydrogen sulfide with gaseous carbon monoxide in the presence of a metal boride, carbide, nitride and/or silicide catalyst, such as titanium carbide, vanadium boride, manganese nitride or molybdenum silicide.

McGuiggan, M.F.; Kuch, P.L.

1984-05-08

142

Brain hydrogen sulfide is severely decreased in Alzheimer's disease  

Microsoft Academic Search

Although hydrogen sulfide (H2S) is generally thought of in terms of a poisonous gas, it is endogenously produced in the brain from cysteine by cystathionine ?-synthase (CBS). H2S functions as a neuromodulator as well as a smooth muscle relaxant. Here we show that the levels of H2S are severely decreased in the brains of Alzheimer's disease (AD) patients compared with

Ko Eto; Takashi Asada; Kunimasa Arima; Takao Makifuchi; Hideo Kimura

2002-01-01

143

Hydrogen Sulfide Is Produced in Response to Neuronal Excitation  

Microsoft Academic Search

Although hydrogen sulfide (H2S) is generally thought of in terms of a poisonous gas, it is endogenously produced in the brain. Physiological concentrations of H2S selectively enhance NMDA receptor-mediated responses and alter the induction of hip- pocampal long-term potentiation (LTP). Here we use cystathi- onine -synthase (CBS) knock-out mice to clearly show that CBS produces endogenous H2S in the brain

Ko Eto; Miki Ogasawara; Ken Umemura; Yasuo Nagai; Hideo Kimura

2002-01-01

144

Endogenous hydrogen sulfide regulation of myocardial injury induced by isoproterenol  

Microsoft Academic Search

Previous work has shown that the endogenous cystathionine ?-synthase (CSE)\\/hydrogen sulfide (H2S) pathway participates in the regulation of cardiac contraction. We hypothesized that the pathway might participate in the pathophysiological regulation of ischemic heart disease. Isoproterenol injection of rat hearts induced a myocardial ischemic injury model, with reduced myocardial and plasma H2S levels, decreased CSE activity, and upregulated CSE gene

Bin Geng; Lin Chang; Chunshui Pan; Yongfen Qi; Jing Zhao; Yongzheng Pang; Junbao Du; Chaoshu Tang

2004-01-01

145

Hydrogen Sulfide Induces Cyclic AMP and Modulates the NMDA Receptor  

Microsoft Academic Search

Hydrogen sulfide (H2S) is produced endogenously from l-cysteine in mammalian tissues, and may function as a neuromodulator in the brain as well as a tone regulator in smooth muscle. H2S is present at relatively high levels in the brain, and cystathionine ?-synthase (CBS), which is highly expressed in the hippocampus, is involved in the production of brain H2S. Physiological concentrations

Hideo Kimura

2000-01-01

146

Astrocytes produce the antiinflammatory and neuroprotective agent hydrogen sulfide  

Microsoft Academic Search

Hydrogen sulfide (H2S) is an essential physiological product in brain. We investigated the expression of cystathionine-?-synthase (CBS) and cystathionine-?-lyase (CGL), the two H2S synthesizing enzymes, in human cell lines and in human brain. Only astrocytes were strongly immunostained for CBS. Cultured astrocytes synthesized H2S at the rate of 15.06?mol\\/g protein\\/h, which was 7.57 fold higher than microglial cells, 10.27 fold

Moonhee Lee; Claudia Schwab; Sheng Yu; Edith McGeer; Patrick L. McGeer

2009-01-01

147

High temperature hydrogen sulfide removal with tin oxide  

Microsoft Academic Search

The system is based on the absorption of hydrogen sulfide (HâS) by stannic (tin) oxide. Two sorbents are required, the first sorbent is tin oxide and the second sorbent is a zinc oxide based material (i.e., zinc ferrite or zinc titanate) which is regenerated by air producing SOâ. TDA`s process carries out a modified Claus reaction to reduce the SOâ

M. E. Karpuk; R. J. Copeland; D. Feinberg; D. Wickham; B. Windecker; J. Yu

1993-01-01

148

Comprehensive monitoring controls hydrogen sulfide in gas-transmission system  

Microsoft Academic Search

Monitoring and controlling hydrogen sulfide (HâS) in a natural-gas transmission environment requires a comprehensive program. Here are the components for such a program along with a discussion of elements of Nova's gas-transmission unit's control efforts. Nova's Alberta gas-transmission division (AGTD) is responsible for the gathering, measuring, quality control, and transmission of Alberta natural gas exported from the province. More than

Tiemstra

1988-01-01

149

The Global Transcriptional Response of Fission Yeast to Hydrogen Sulfide  

Microsoft Academic Search

BackgroundHydrogen sulfide (H2S) is a newly identified member of the small family of gasotransmitters that are endogenous gaseous signaling molecules that have a fundamental role in human biology and disease. Although it is a relatively recent discovery and the mechanism of H2S activity is not completely understood, it is known to be involved in a number of cellular processes; H2S

Xu Jia; Weizhi He; Alastair I. H. Murchie; Dongrong Chen

2011-01-01

150

Hydrogen Sulfide Scavenges the Cytotoxic Lipid Oxidation Product 4-HNE  

Microsoft Academic Search

Highly reactive ?,?-unsaturated aldehydes like 4-hydroxy-2-nonenal (4-HNE), generated from oxidation of polyunsaturated fatty\\u000a acids, can bind to proteins, polynucleotides and exert cytotoxicity. 4-HNE is known to react readily with thiol and amino\\u000a groups on free or bound amino acids. Recently, hydrogen sulfide (H2S) has been identified as an endogenous vascular gasotransmitter and neuromodulator which can reach up to 160 ?mol\\/l in

Sabine M. Schreier; Markus K. Muellner; Hannes Steinkellner; Marcela Hermann; Harald Esterbauer; Markus Exner; Bernhard M. K. Gmeiner; Stylianos Kapiotis; Hilde Laggner

2010-01-01

151

Control of malodorous hydrogen sulfide compounds using microbial fuel cell.  

PubMed

In this study, a microbial fuel cell (MFC) was used to control malodorous hydrogen sulfide compounds generated from domestic wastewaters. The electricity production demonstrated a distinct pattern of a two-step increase during 170 h of system run: the first maximum current density was 118.6 ± 7.2 mA m(-2) followed by a rebound of current density increase, reaching the second maximum of 176.8 ± 9.4 mA m(-2). The behaviors of the redox potential and the sulfate level in the anode compartment indicated that the microbial production of hydrogen sulfide compounds was suppressed in the first stage, and the hydrogen sulfide compounds generated from the system were removed effectively as a result of their electrochemical oxidation, which contributed to the additional electricity production in the second stage. This was also directly supported by sulfur deposits formed on the anode surface, which was confirmed by analyses on those solids using a scanning electron microscope equipped with energy dispersive X-ray spectroscopy as well as an elemental analyzer. To this end, the overall reduction efficiencies for HS(-) and H2S(g) were as high as 67.5 and 96.4 %, respectively. The correlations among current density, redox potential, and sulfate level supported the idea that the electricity signal generated in the MFC can be utilized as a potential indicator of malodor control for the domestic wastewater system. PMID:23297068

Eaktasang, Numfon; Min, Hyeong-Sik; Kang, Christina; Kim, Han S

2013-01-08

152

Experimental study of polysulfane stability in gaseous hydrogen sulfide  

NASA Astrophysics Data System (ADS)

The solubility of sulfur in gaseous hydrogen sulfide has been studied in the H 2S-S system. Experiments were carried out at temperatures between 50 and 290°C and pressures up to 200 bars. The experimentally determined concentrations of sulfur in the gas phase are 6-7 orders of magnitude higher than the corresponding concentrations calculated for a system free of hydrogen sulfide. The results of experiments show significant interaction between S and H 2S. These interactions can be of two kind: solvation by hydrogen sulfide (solubility), as with formation of new stable gaseous chemical compounds, like polysulfanes (chemical reaction). The data obtained can be reasonably well described by the formation of a H 2S · S compound. Thermodynamic parameters for polysulfanes and equilibrium compositions of the S-H 2S system have been calculated ab initio for the experimental conditions. At temperatures above 170°C, results (of calculations) are in good agreement with experimental data, although the difference between the calculated and experimental mole fraction of the sulfur in the gas phase reaches 2 orders of magnitude at 125-170°C. It is theorized that sulfur solubility in gaseous H 2S is related to two main chemical reactions, dominated in the different temperature ranges: sulfur solvation by H 2S (125-170°C) and polysulfane formation (200-290°C).

Migdisov, Art A.; Suleimenov, O. M.; Alekhin, Yu V.

1998-08-01

153

High temperature solar thermochemical processing - Hydrogen and sulfur from hydrogen sulfide  

NASA Astrophysics Data System (ADS)

Sunlight, concentrated to high intensities, has a rarely recognized potential for adding process heat to reactors at high temperatures. Hydrogen sulfide is a by-product of the sweetening of fossil fuels. In this paper, by way of example, the production of hydrogen and sulfur from hydrogen sulfide is used as a device for showing how solar processing might be considered as a successor to a currently used industrial process, the Claus process. It is concluded that this and other processes should be explored as means of using as well as storing solar energy.

Noring, J. E.; Fletcher, E. A.

1982-08-01

154

Synthesis and evaluation of phosphorodithioate-based hydrogen sulfide donors.  

PubMed

A series of O-aryl- and alkyl-substituted phosphorodithioates were designed and synthesized as hydrogen sulfide (H2S) donors. H2S releasing capability of these compounds was evaluated using fluorescence methods. O-aryl substituted donors showed slow and sustained H2S release while O-alkylated compounds showed very weak H2S releasing capability. We also evaluated donors' protective effects against hydrogen peroxide (H2O2)-induced oxidative damage in myocytes and donors' toxicity toward B16BL6 mouse melanoma cells. PMID:23917226

Park, Chung-Min; Zhao, Yu; Zhu, Zhaohui; Pacheco, Armando; Peng, Bo; Devarie-Baez, Nelmi O; Bagdon, Powell; Zhang, Hui; Xian, Ming

2013-10-01

155

Rate of reaction of hydrogen sulfide-carbonyl sulfide mixtures with fully calcined dolomite  

SciTech Connect

Kinetic data are obtained by a gravimetric technique for rates of reaction of calcium oxide in fully calcined dolomite with hydrogen sulfide and hydrogen sulfide-carbonyl sulfide mixtures. The data are presented as values for a factor k defined by d(CAO) = -k (CAO) dt. At 600, 700, and 800 degrees C with (H/sub 2/S) from 0.5% to 5.0% by volume and (H/sub 2/S)/(COS) = 20 for mixtures, expressions for k show apparent rate constants and the dependence on sulfurous gas concentration. For example, at 700 degrees C, k = 1.43 x 10/sup -4/ (h2s) 1.06/S and k = 1.70 x 10/sup -4/ (H/sub 2/S + COS) 1.00/s. Since the date show first-order dependence on calcium oxide, k's for H/sub 2/S alone as the sulfurous gas and h2s-cos mixtures can be obtained for the same sample, free from scatter due to variations from sample to sample. Addition of values for k from runs with H/sub 2/S as the only sulfurous gas and runs with COS as the only sulfurous gas are compared to measurements with actual mixtures. K's for the mixtures are approximately 30% higher than the sum of the appropriate separate values.

Kamath, V.S.; Petrie, T.W.

1981-01-01

156

Near-continuous measurement of hydrogen sulfide and carbonyl sulfide by an automatic gas chromatograph  

SciTech Connect

The article describes an automatic gas chromatograph with a flame photometric detector (GC-FPD) that samples and analyzes hydrogen sulfide (H2S) and carbonyl sulfide (COS) at 30-sec intervals. Temperature programming was used to elute trace amounts of carbon disulfide (CS2) present in each injection from a Supelpak-S column in a single peak at the end of 15 min runs. The system was used to study the high-temperature fuel-rich sulfur capture reactions of H2S and COS with injected calcium oxide (CaO) sorbent, necessitating the near continuous measurement of these gaseous sulfur species. The H2S concentration ranged from 300 to 3000 ppm, and the COS from 30 to 300 ppm. The system was also used to monitor sulfur dioxide (SO2) levels under fuel-lean conditions: results compared very closely with SO2 measurements made simultaneously with continuous ultraviolet (UV) SO2 instrumentation.

Lindgren, E.R.; Pershing, D.W.; Kirchgessner, D.A.; Drehmel, D.C.

1991-01-01

157

Effect of hydrogen sulfide on phosphorus lability in lake sediments amended with drinking water treatment residuals.  

PubMed

The use of drinking water treatment residuals (WTRs) to immobilize P in sediments is a novel approach for lake restoration. However, the lability of P in WTRs-amended sediments may vary with many factors, e.g., hydrogen sulfide content. Earlier works in our laboratory have demonstrated that WTRs are effective sorbents for hydrogen sulfide in water. Thus, we hypothesized that the lability of P in WTRs-amended sediments would not be increased by hydrogen sulfide. The results of this work suggested that this hypothesis was tenable. Compared to the raw sediments, the amended sediments had significantly lower P desorption potential in the presence of hydrogen sulfide at different times, pH and concentrations. Moreover, the amended sediments were also better able to adsorb hydrogen sulfide. In the amended sediments, the P, which was easily desorbed due to the effect of hydrogen sulfide, was transformed into the Fe/Al bound P. PMID:23453604

Wang, Changhui; Liu, Juanfeng; Pei, Yuansheng

2013-03-01

158

The electronic structure and catalytic properties of molybdenum sulfides in the coal hydrogenation process  

SciTech Connect

Comparative analysis of the electronic structure of molybdenum sulfides and their catalytic activity in hydrogenation reactions was performed from the results of Hartree-Fock ab initio quantum-chemical calculations using the STO 3-21G and 6-311G basis sets with geometry optimization. The model reactions of hydrogenation of aromatic and saturated hydrocarbons with hydrogen and hydrogen sulfide were studied. It was shown that the hydrogenation reactions of aromatic hydrocarbons with hydrogen sulfide must occur at a higher rate (with lower activation energy) as compared to those with molecular hydrogen.

A.M. Gyul'maliev; M.A. Gyul'malieva; A.S. Maloletnev; M.Ya. Shpirt [Institute for Fossil Fuels, Moscow (Russia)

2008-08-15

159

Process for removing hydrogen sulfide from gases particularly coal pyrolysis gases  

SciTech Connect

Hydrogen sulfide is first removed by ammoniacal liquor from coke oven gas in the bottom part of a gas scrubber. In the top part of the scrubber, two consecutively-arranged fine scrubbing stages remove hydrogen sulfide by treating the gases, in the upper stage, with a caustic soda solution or a caustic potash solution. Beneath the upper scrubbing stage is the second fine scrubbing stage fed with a subflow of an aqueous carbonate solution collecting at the outlet of the upper fine scrubbing stage and a subflow of cooled, regenerated carbonate solution discharged from the hydrogen-sulfide/hydrogen-cyanide stripper. From the hydrogen-sulfide/hydrogen-cyanide stripper, a second subflow is admixed with coal liquor for removing fixed ammonia therefrom in a separator. The separator produces water vapor with carbon dioxide vapors that are delivered to the hydrogen-sulfide/hydrogen-cyanide stripper for regenerating the aqueous carbonate washing solution.

Ritter, H.; Herpers, E.T.

1985-02-12

160

Thermolysis of hydrogen sulfide in the temperature range 1350--1600 K  

Microsoft Academic Search

The thermal dissociation of hydrogen sulfide gives promise of becoming an economic method to convert a hazardous waste into valuable products, conserve fossil fuels, and increase usable reserves of fossil fuels. The dissociation rates at temperatures which are attractive for an industrial process are not well-characterized. The authors studied the dissociation of hydrogen sulfide into hydrogen and sulfur at temperatures

William S. Harvey; Jane H. Davidson; Edward A. Fletcher

1998-01-01

161

Hydrogenation of sulfur dioxide to hydrogen sulfide on chromium promoted Fe\\/SiO 2 catalysts  

Microsoft Academic Search

The hydrogenation of sulfur dioxide to hydrogen sulfide was studied over a series of Fe-Si-Cr catalysts in a flow reactor. These catalysts were prepared by co-precipitation of iron nitrate, sodium silicate and chromium nitrate, which had Cr\\/Fe atomic ratios of 0–0.04 and Si\\/Fe atomic ratios of 0–1.2. The addition of Cr and Si dramatically improved the SO2 hydrogenation activity of

Kuo-Tseng Li; Yao-Chun Hung; Tien-Ting Ko

2003-01-01

162

Identification of genes affecting hydrogen sulfide formation in Saccharomyces cerevisiae.  

PubMed

A screen of the Saccharomyces cerevisiae deletion strain set was performed to identify genes affecting hydrogen sulfide (H(2)S) production. Mutants were screened using two assays: colony color on BiGGY agar, which detects the basal level of sulfite reductase activity, and production of H(2)S in a synthetic juice medium using lead acetate detection of free sulfide in the headspace. A total of 88 mutants produced darker colony colors than the parental strain, and 4 produced colonies significantly lighter in color. There was no correlation between the appearance of a dark colony color on BiGGY agar and H(2)S production in synthetic juice media. Sixteen null mutations were identified as leading to the production of increased levels of H(2)S in synthetic juice using the headspace analysis assay. All 16 mutants also produced H(2)S in actual juices. Five of these genes encode proteins involved in sulfur containing amino acid or precursor biosynthesis and are directly associated with the sulfate assimilation pathway. The remaining genes encode proteins involved in a variety of cellular activities, including cell membrane integrity, cell energy regulation and balance, or other metabolic functions. The levels of hydrogen sulfide production of each of the 16 strains varied in response to nutritional conditions. In most cases, creation of multiple deletions of the 16 mutations in the same strain did not lead to a further increase in H(2)S production, instead often resulting in decreased levels. PMID:18192430

Linderholm, Angela L; Findleton, Carrie L; Kumar, Gagandeep; Hong, Yeun; Bisson, Linda F

2008-01-11

163

Therapeutic applications of organosulfur compounds as novel hydrogen sulfide donors and/or mediators.  

PubMed

Hydrogen sulfide, once considered as toxic gas, is now recognized as an important biological mediator. The deficiency of hydrogen sulfide could lead to various pathological changes, such as arterial and pulmonary hypertension, Alzheimer's disease, gastric mucosal injury and liver cirrhosis. However, excessive production of hydrogen sulfide, by using inorganic hydrogen sulfide donors such as NaHS, may contribute to the pathogenesis of inflammatory diseases, septic shock, cerebral stroke and mental retardation in patients with Down syndrome. Therefore, an increasing interest in organic molecules that are capable of regulating the formation of hydrogen sulfide has extended in recent years. Allium vegetables are one natural source of organic sulfur-containing compounds and have been widely investigated regarding their therapeutic applications, and it has been proven that the ingredients of garlic, such as diallyl disulfide, diallyl trisulfide and S-ally cysteine act as hydrogen sulfide donors or mediators in pharmaceutical studies. In addition, S-propargyl cysteine (ZYZ-802) and S-propyl cysteine, two synthetic cysteine analogs, have been examined and could be used to treat ischemic heart disease via modulation of the hydrogen sulfide pathway. In addition, drugs containing hydrogen sulfide-releasing moieties have been synthesized and widely reported in recent years, such as S-nonsteroidal anti-inflammatory drugs and the derivative of Lawesson's reagents, which exhibit varied biological effects in experiments. As cystathionine ?-synthase and cystathionine ?-lyase are the enzymes that are able to catalyze the production of endogenous hydrogen sulfide from cysteine, their inhibitors, such as dl-propylargylglycine and ?-cyanoalanine, have been frequently used in studies on the biological mechanism of hydrogen sulfide. All these hydrogen sulfide donors, mediators and inhibitors have provided useful tools in the research of a variety of biological effects and are promising drug candidates of hydrogen sulfide. PMID:22115353

Gu, Xianfeng; Zhu, Yi Zhun

2011-01-01

164

Hydrogen sulfide spatial distribution and exposure in deep-pit swine housing  

Microsoft Academic Search

The objectives of this research focus on investigating spatial distribution of hydrogen sulfide gas associated with manure removal and agitation events in deep-pit swine production facilities as well as assessing exposure or potential exposure to hydrogen sulfide before, during, and after manure removal and agitation events.\\u000aThe specific objectives of this study were: (1) Implement a wireless hydrogen sulfide monitoring

Randy John Swestka

2010-01-01

165

Reaction-based genetically encoded fluorescent hydrogen sulfide sensors.  

PubMed

The detection of hydrogen sulfide (H(2)S), a toxic gas and an important biological signaling molecule, has been a long-time challenge. Here we report genetically encoded fluorescent protein (FP)-based probes that can selectively detect H(2)S. By expanding the genetic codes of E. coli and mammalian cells, FP chromophores were modified with the sulfide-reactive azide functional group. These structurally modified chromophores were selectively reduced by H(2)S, resulting in sensitive fluorescence enhancement detectable by spectroscopic and microscopic techniques. Exploration of a circularly permuted FP led to an improved sensor with faster responses, and the feasibility of using such a genetically encoded probe to monitor H(2)S in living mammalian cells has also been demonstrated. PMID:22642566

Chen, Si; Chen, Zhi-jie; Ren, Wei; Ai, Hui-wang

2012-05-31

166

Surface modification effects on hydrogen permeation in high-temperature, high-pressure, hydrogen-hydrogen sulfide environments  

SciTech Connect

Surface modifications on chromium-molybdenum (Cr-Mo) steel were tested for hydrogen (H) permeation and corrosion protection in a hydrogen-hydrogen sulfide (H[sub 2]-H[sub 2]S) environment. Virgin thermal spray coating showed no resistance to H permeation. Virgin metal coating, aluminum (Al) hot-dipped plating, Al diffusion coating, and Cr diffusion coating worked as barriers to H permeation, apparently by means of a superficial oxide or passivation film. Virgin ceramic coating by chemical vapor deposition (CVD) also worked as a barrier to H permeation. After testing of specimens as coated, coating materials were sulfidized to simulate the surface after use in a corrosive environment containing H[sub 2]S and then were tested for H permeation. Thermal spray coatings with a layer of aluminum oxide (Al[sub 2]O[sub 3])-50% nickel (Ni)-50% Cr acquired resistance to H permeation after sulfidization. Resistance to H permeation of metal coatings such as the Al hot-dipped plating, Al diffusion coating, and Cr diffusion coating decreased after sulfidization, but remained at a satisfactory level. Ceramic coatings by CVD lost resistance to H permeation with increasing times of sulfidization. Thermal spray and metal coatings retained corrosion resistance against sulfidization. The corrosion resistance of ceramic coatings by CVD gradually deteriorated with time of sulfidization. Of the surface modifications studied, thermal spray coatings were considered feasible for practical applications.

Fukai, T.; Matsumoto, K. (Mitsui SRC Development Co. Ltd., Chiba (Japan). Technical Development Div.)

1994-07-01

167

Mitochondrial depolarization following hydrogen sulfide exposure in erythrocytes from a sulfide-tolerant marine invertebrate  

Microsoft Academic Search

Sulfide-tolerant marine invertebrates employ a variety of mechanisms to detoxify sulfide once it has entered their bodies, but their integumentary, respiratory epithelium and circulatory cells may still be exposed to toxic sulfide concentrations. To investigate whether sulfide exposure is toxic to mitochondria of a sulfide-tolerant invertebrate, we used the fluorescent dyes JC-1 and TMRM to determine the effect of sulfide

David Julian; Kelly L. April; Shiven Patel; Jenny R. Stein; Stephanie E. Wohlgemuth

168

Formation of cubic zinc sulfide nanocrystals in paraffin liquid  

Microsoft Academic Search

A green and cheap route to the production of cubic zinc sulfide nanocrystals is presented. Nanocrystals were synthesized in sole solvent paraffin liquid with zinc oxide, elemental sulfur and oleic acid. Their photophysical properties were investigated by UV–vis absorption and photoluminescence spectra. The temporal evolution of UV–vis spectra showed that the reactions could be terminated after about 5 min growth with

Xinyu Ye; Ying Fang; Yunsheng Hu; Tian Xia; Weidong Zhuang; Zhen Long

2007-01-01

169

30 CFR 250.245 - What hydrogen sulfide (H2S) information must accompany the DPP or DOCD?  

Code of Federal Regulations, 2010 CFR

... What hydrogen sulfide (H2S) information...Development and Production Plans (dpp...250.245 What hydrogen sulfide (H2S) information...development and production activities. ...release from the facilities you will use...

2010-07-01

170

30 CFR 250.245 - What hydrogen sulfide (H2S) information must accompany the DPP or DOCD?  

Code of Federal Regulations, 2010 CFR

... What hydrogen sulfide (H2S) information...Development and Production Plans (dpp...250.245 What hydrogen sulfide (H2S) information...development and production activities. ...release from the facilities you will use...

2009-07-01

171

Removal of Hydrogen Sulfide from Simulated Geothermal Brines by Reaction with Oxygen. Final Report, October 6, 1975-February 4, 1977.  

National Technical Information Service (NTIS)

A process for controlling hydrogen sulfide emissions and corrosivity in geothermal systems has been evaluated on a small laboratory pilot plant scale and shown to be technically feasible. The hydrogen sulfide was oxidized by oxygen injected directly into ...

J. S. Wilson J. E. King G. R. Bullard

1977-01-01

172

ESTIMATIONS OF AMMONIA AND HYDROGEN SULFIDE FLUXES FROM CATTLE FEEDLOT SURFACES IN TEXAS HIGH PLAINS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Emissions of ammonia, hydrogen sulfide and other gases from concentrated animal feeding operations and there impacts on the environment are of increasing concern to producers, regulators, and the general public. The emissions of ammonia and hydrogen sulfide from beef cattle feedyards and the biolog...

173

30 CFR 550.215 - What hydrogen sulfide (H2S) information must accompany the EP?  

Code of Federal Regulations, 2013 CFR

... 2013-07-01 2013-07-01 false What hydrogen sulfide (H2S) information must accompany the EP? 550...Contents of Exploration Plans (ep) § 550.215 What hydrogen sulfide (H2 S) information must accompany the EP?...

2013-07-01

174

Presumed hydrogen sulfide-mediated neurotoxicity after streptococcus anginosus group meningitis.  

PubMed

Hydrogen sulfide is an environmental toxicant and gaseous neurotransmitter. It is produced enterically by sulfur-reducing bacteria and invasive pathogens including Streptococcus anginosus group, Salmonella and Citrobacter. We describe putative focal hydrogen sulfide neurotoxicity after Streptococcus constellatus meningitis, treated with adjunctive sodium nitrite and hyperbaric oxygen therapy. PMID:23014355

Verma, Sumit; Landisch, Rachel; Quirk, Brendan; Schmainda, Kathleen; Prah, Melissa; Whelan, Harry T; Willoughby, Rodney E

2013-02-01

175

Potential Explosive Hazards from Hydrogen Sulfide Production in Ship Ballast and Sewage Tanks.  

National Technical Information Service (NTIS)

Hydrogen sulfide produced by sulfate-reducing bacteria is a well recognized toxic hazard in storage tanks on HMA Ships, however, it also has the potential to be an explosive hazard. Hydrogen sulfide can cause explosions when its concentration exceeds 4% i...

L. E. Fletcher

1998-01-01

176

ESTIMATION OF AMMONIA AND HYDROGEN SULFIDE EMISSIONS FROM CATTLE FEEDLOTS IN TEXAS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Emissions of ammonia, hydrogen sulfide and other gases from concentrated animal feeding operations and there impacts on the environment are of increasing concern to producers, regulators, and the general public. The emissions of ammonia and hydrogen sulfide from beef cattle feedyards and the biolog...

177

Catalysts for the selective oxidation of hydrogen sulfide to sulfur  

DOEpatents

This invention provides catalysts for the oxidation of hydrogen sulfide. In particular, the invention provides catalysts for the partial oxidation of hydrogen sulfide to elemental sulfur and water. The catalytically active component of the catalyst comprises a mixture of metal oxides containing titanium oxide and one or more metal oxides which can be selected from the group of metal oxides or mixtures of metal oxides of transition metals or lanthanide metals. Preferred metal oxides for combination with TiO.sub.2 in the catalysts of this invention include oxides of V, Cr, Mn, Fe, Co, Ni, Cu, Nb, Mo, Tc, Ru, Rh, Hf, Ta, W, Au, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu. Catalysts which comprise a homogeneous mixture of titanium oxide and niobium (Nb) oxide are also provided. A preferred method for preparing the precursor homogenous mixture of metal hydroxides is by coprecipitation of titanium hydroxide with one or more other selected metal hydroxides. Catalysts of this invention have improved activity and/or selectivity for elemental sulfur production. Further improvements of activity and/or selectivity can be obtained by introducing relatively low amounts (up to about 5 mol %)of a promoter metal oxide (preferably of metals other than titanium and that of the selected second metal oxide) into the homogeneous metal/titanium oxide catalysts of this invention.

Srinivas, Girish (Thornton, CO); Bai, Chuansheng (Baton Rouge, LA)

2000-08-08

178

Modeling of Syngas Reactions and Hydrogen Generation Over Sulfides  

SciTech Connect

The objective of the research is to analyze pathways of reactions of hydrogen with oxides of carbon over sulfides, and to predict which characteristics of the sulfide catalyst (nature of metal, defect structure) give rise to the lowest barriers toward oxygenated hydrocarbon product. Reversal of these pathways entails the generation of hydrogen, which is also proposed for study. In this first year of study, adsorption reactions of H atoms and H{sub 2} molecules with MoS{sub 2}, both in molecular and solid form, have been modeled using high-level density functional theory. The geometries and strengths of the adsorption sites are described and the methods used in the study are described. An exposed MO{sup IV} species modeled as a bent MoS{sub 2} molecule is capable of homopolar dissociative chemisorption of H{sub 2} into a dihydride S{sub 2}MoH{sub 2}. Among the periodic edge structures of hexagonal MoS{sub 2}, the (1{bar 2}11) edge is most stable but still capable of dissociating H{sub 2}, while the basal plane (0001) is not. A challenging task of theoretically accounting for weak bonding of MoS{sub 2} sheets across the Van der Waals gap has been addressed, resulting in a weak attraction of 0.028 eV/MoS{sub 2} unit, compared to the experimental value of 0.013 eV/MoS{sub 2} unit.

Kamil Klier; Jeffery A. Spirko; Michael L. Neiman

2002-09-17

179

Superconductivity in liquid metallic hydrogen  

Microsoft Academic Search

By solving the Eliashberg equations for the gap function, the super-conducting transition temperature of a proposed low-temperature liquid state of metallic hydrogen is found to be comparable to that obtained, with similar approximations, for the solid. This indicates that metallic hydrogen may be a superconducting liquid in the density range 1.6> or =r\\/sub s\\/> or =1.3, where the melting point

J. E. Jaffe; N. W. Ashcroft

1981-01-01

180

Surface Modification Effects on Hydrogen Permeation in High-Temperature, High-Pressure, Hydrogen-Hydrogen Sulfide Environments  

Microsoft Academic Search

Surface modifications on chromium-molybdenum (Cr-Mo) steel were tested for hydrogen (H) permeation and corrosion protection in a hydrogen-hydrogen sulfide (H[sub 2]-H[sub 2]S) environment. Virgin thermal spray coating showed no resistance to H permeation. Virgin metal coating, aluminum (Al) hot-dipped plating, Al diffusion coating, and Cr diffusion coating worked as barriers to H permeation, apparently by means of a superficial oxide

T. Fukai; K. Matsumoto

1994-01-01

181

Liquid-Hydrogen-Fueled Buick.  

National Technical Information Service (NTIS)

A 1979 Buick Century sedan with a 3.8-l (231-in. exp 3 ) displacement turbocharged V-6 engine and automatic transmission was converted to operation on hydrogen supplied to the engine from a liquid-hydrogen tank installed in the trunk of the car. The liqui...

W. F. Stewart

1980-01-01

182

Factors controlling the reactivity of hydrogen sulfide with hemeproteins†  

PubMed Central

Hemoglobin I (HbI) from the clam Lucina pectinata is an intriguing hemeprotein that binds and transports H2S to sulfide-oxidizing chemoautotrophic bacteria to maintain a symbiotic relationship and to protect the mollusk from H2S toxicity. Single point mutations at E7, B10 and E11 positions were introduced in the HbI heme pocket to define the reactivity of sulfide with hemeproteins. The functional and structural properties of mutant and wild type recombinant proteins were first evaluated using the well-known ferrous CO and O2 derivatives. The effects of these mutations on the ferric environment were then studied in the metaquo and hydrogen sulfide derivatives. The results obtained with the ferrous HbI mutants show that all the E7 substitutions and the PheB10Tyr mutation influence directly CO and O2 binding and stability while the B10 and E11 substitutions induce distal structural rearrangements that affect ligand entry and escape indirectly. For the metaquo-GlnE7His, PheB10Val, PheB10Leu and the E11 variants, two individual distal structures are suggested, one of which is associated with H-bonding interactions between the E7 residues and the bound water. Similar H-bonding interactions are invoked for these HbI-H2S mutant derivatives and the rHbI, altering in turn sulfide reactivity within these protein samples. This is evident in the resonance Raman spectra of these HbI-H2S complexes, which show reduction of heme iron as judged by the appearance of the ?4 oxidation state marker at 1356 cm?1, indicative of heme-FeII species. This reduction process depends strongly on distal mutations showing faster reduction for those HbI mutants exhibiting strongest H-bonding interactions. Overall, the results presented here show that: a. H2S association is regulated by steric constraints; b. H2S release is controlled by two competing reactions involving simple sulfide dissociation and heme reduction; c. at high H2S concentrations, reduction of the ferric center dominates; d. reduction of the heme is also enhanced in those HbI mutants having polar distal environments.

Pietri, Ruth; Lewis, Ariel; Leon, Ruth G.; Casabona, Gullermina; Kiger, Laurent; Yeh, Syun-Ru; Fernandez-Alberti, Sebastian; Marden, Michael C.; Cadilla, Carmen L.; Lopez-Garriga, Juan

2009-01-01

183

Effects of atmospheric hydrogen sulfide concentration on growth and meat quality in broiler chickens.  

PubMed

A total of 384 commercial Arbor Acres broilers (one-half males and one-half females; 1 d of age) were randomly allotted to 4 treatments to study the effects of atmospheric hydrogen sulfide on growth performance, blood parameters, and meat quality. Each treatment was placed in a separate environmentally controlled chamber. Group A was the control group; no hydrogen sulfide was added to chamber A to maintain near 0 mg/kg of hydrogen sulfide from wk 0 to 6. Groups B, C, and D were trial groups that were subjected to 2, 4, and 8 mg/kg of hydrogen sulfide, respectively, from wk 0 to 3 and to 3, 6, and 12 mg/kg of hydrogen sulfide, respectively, from wk 4 to 6. The results showed that the average daily intake and BW decreased whereas feed:gain and concentration of hydrogen sulfide increased from wk 0 to 3. The number of white blood cells, red blood cells, and hematocrit increased slightly with increasing exposure to hydrogen sulfide, but no significant difference was found. The highly concentrated hydrogen sulfide (12 mg/kg) significantly decreased the yield of carcass and pH of leg and increased water loss rate of breast and leg. Therefore, the results suggest that hydrogen sulfide had a negative effect on the performance of broilers and that the suitable hydrogen sulfide concentration should be less than 2 mg/kg from 0 to 3 wk of age and less than 6 mg/kg from 3 to 6 wk of age for broiler production and health. PMID:22010223

Wang, Y; Huang, M; Meng, Q; Wang, Y

2011-11-01

184

Carbonyl sulfide removal with compost and wood chip biofilters, and in the presence of hydrogen sulfide.  

PubMed

Carbonyl sulfide (COS) is an odor-causing compound and hazardous air pollutant emitted frequently from wastewater treatment facilities and chemical and primary metals industries. This study examined the effectiveness of biofiltration in removing COS. Specific objectives were to compare COS removal efficiency for various biofilter media; to determine whether hydrogen sulfide (H2S), which is frequently produced along with COS under anaerobic conditions, adversely impacts COS removal; and to determine the maximum elimination capacity of COS for use in biofilter design. Three laboratory-scale polyvinyl chloride biofilter columns were filled with up to 28 in. of biofilter media (aged compost, fresh compost, wood chips, or a compost/wood chip mixture). Inlet COS ranged from 5 to 46 parts per million (ppm) (0.10-9.0 g/m3 hr). Compost and the compost/wood chip mixture produced higher COS removal efficiencies than wood chips alone. The compost and compost/wood chip mixture had a shorter stabilization times compared with wood chips alone. Fresh versus aged compost did not impact COS removal efficiency. The presence of H2S did not adversely impact COS removal for the concentration ratios tested. The maximum elimination capacity is at least 9 g/m3 hr for COS with compost media. PMID:20066911

Sattler, Melanie L; Garrepalli, Divya R; Nawal, Chandraprakash S

2009-12-01

185

Biogeochemistry of dissolved hydrogen sulfide species and carbonyl sulfide in the western North Atlantic Ocean  

NASA Astrophysics Data System (ADS)

The biogeochemistry of total sulfide dissolved in the open ocean is a poorly understood component of the global sulfur cycle. Here, the cycling of total sulfide was examined in the western North Atlantic Ocean using specially developed sampling and analytical methods. Total sulfide (particulate + dissolved sulfide) concentrations ranged from <2-550 pmol/L; concentrations were highest in the mixed layer and decreased with depth. Significant levels (up to 19 pmol/L) of free sulfide (uncomplexed sulfide) were determined in the top 50 m of the water column. Sources of total sulfide were examined. In particular, the rate of carbonyl sulfide (OCS) hydrolysis was redetermined under oceanographic conditions, and the depth distribution of OCS was examined. The patterns of near-surface enrichment (up to 150 pmol/L) and depletion at depth observed in OCS depth profiles suggest in situ production of OCS. To quantify the sources and sinks of total sulfide in the mixed layer of the Sargasso Sea, a budget was constructed. The rate of total sulfide production was 5.5 pmol L -1 h -1 (OCS hydrolysis + atmospheric input), and total sulfide removal rate was 115 pmol L -1 h -1 (oxidation + particulate sinking). The significant difference between the known sources and sinks indicates that other processes are important for the cycling of sulfide. Similarities in the depth distribution of total sulfide and chlorophyll a, and results from recent laboratory experiments argue strongly in favor of biological involvement in the production of total sulfide in the open ocean.

Radford-Kn?ry, Joël; Cutter, Gregory A.

1994-12-01

186

High temperature hydrogen sulfide removal with tin oxide  

SciTech Connect

The system is based on the absorption of hydrogen sulfide (H{sub 2}S) by stannic (tin) oxide. Two sorbents are required, the first sorbent is tin oxide and the second sorbent is a zinc oxide based material (i.e., zinc ferrite or zinc titanate) which is regenerated by air producing SO{sub 2}. TDA`s process carries out a modified Claus reaction to reduce the SO{sub 2} from the second sorbent generation to elemental sulfur. In this case the sulfided stannic oxide forms stannous sulfide (SnS) which reduces the SO{sub 2}. The absorption by SnO{sub 2} could remove over 90% of the H{sub 2}S from typical coal gas streams, but we use zinc ferrite (or zinc titanate), (a) to reduce H{sub 2}S to less than 20 ppM and (b) as a source of SO{sub 2} in regeneration. Due to stoichiometry of regeneration we want to remove half of the H{sub 2}S by SnO{sub 2} and the remainder by the second sorbent. The reactions with stannic oxide minimize the heat released during H{sub 2}S removal and regeneration. The absorption by SnO{sub 2} is slightly endothermic and cools the gas stream by less that 5{degrees}F (2.8{degrees}C) during absorption. Regeneration with SO{sub 2} is exothermic but releases only 11% of the heat that is liberated in regenerating the ZnO. For a nominal 6.5:1 steam to air the regeneration of ZnO increases the temperature by {approx_equal}400{degrees}F. The regeneration of SnO{sub 2} increases the temperature by less than 50{degrees}F (28{degrees}C) in the same gas flow.

Karpuk, M.E.; Copeland, R.J.; Feinberg, D.; Wickham, D.; Windecker, B.; Yu, J.

1993-09-01

187

Analytical measurement of discrete hydrogen sulfide pools in biological specimens.  

PubMed

Hydrogen sulfide (H?S) is a ubiquitous gaseous signaling molecule that plays a vital role in numerous cellular functions and has become the focus of many research endeavors, including pharmacotherapeutic manipulation. Among the challenges facing the field is the accurate measurement of biologically active H?S. We have recently reported that the typically used methylene blue method and its associated results are invalid and do not measure bona fide H?S. The complexity of analytical H?S measurement reflects the fact that hydrogen sulfide is a volatile gas and exists in the body in various forms, including a free form, an acid-labile pool, and bound as sulfane sulfur. Here we describe a new protocol to discretely measure specific H?S pools using the monobromobimane method coupled with RP-HPLC. This new protocol involves selective liberation, trapping, and derivatization of H?S. Acid-labile H?S is released by incubating the sample in an acidic solution (pH 2.6) of 100 mM phosphate buffer with 0.1mM diethylenetriaminepentaacetic acid (DTPA), in an enclosed system to contain volatilized H?S. Volatilized H?S is then trapped in 100 mM Tris-HCl (pH 9.5, 0.1 mM DTPA) and then reacted with excess monobromobimane. In a separate aliquot, the contribution of the bound sulfane sulfur pool was measured by incubating the sample with 1 mM TCEP (tris(2-carboxyethyl)phosphine hydrochloride), a reducing agent, to reduce disulfide bonds, in 100 mM phosphate buffer (pH 2.6, 0.1 mM DTPA), and H?S measurement was performed in a manner analogous to the one described above. The acid-labile pool was determined by subtracting the free hydrogen sulfide value from the value obtained by the acid-liberation protocol. The bound sulfane sulfur pool was determined by subtracting the H?S measurement from the acid-liberation protocol alone compared to that of TCEP plus acidic conditions. In summary, our new method allows very sensitive and accurate measurement of the three primary biological pools of H?S, including free, acid-labile, and bound sulfane sulfur, in various biological specimens. PMID:22561703

Shen, Xinggui; Peter, Elvis A; Bir, Shyamal; Wang, Rui; Kevil, Christopher G

2012-04-19

188

Fluorometric field instrument for continuous measurement of atmospheric hydrogen sulfide.  

PubMed

A sensitive (limit of detection approximately <100 pptv at S/N = 3), fully automated, portable (32 x 25 x 38 cm, 4.5 kg) instrument has been designed for continuous field measurement of atmospheric hydrogen sulfide. Air is sampled by a PTFE membrane-based diffusion scrubber and collected into an aLkaline fluorescein mercuric acetate (FMA) solution flowing under a controlled and constant pneumatic pressure. The collected sulfide quenches the fluorescence that is measured with a miniature blue LED photodiode-based fluorescence detector. Acquisition and interpretation of signal and all flow control are carried out via a mininotebook personal computer (PC) using custom software written in HP-VEE. The instrument provides for self-calibration and zero functions using an on-board permeation tube enclosed in a thermostated block, at any preprogrammed desired interval. During sampling, the computed H2S concentration is stored every 2 min. The complete system, including the PC, is operated in the field by a 12-V marine battery. The system was field tested near oil field operations in West Texas and showed good correlations with a concurrently operated lead acetate tape-based commercial sampler, with a response speed and time resolution much better than that of the latter instrument. PMID:11774912

Toda, K; Dasgupta, P K; Li, J; Tarver, G A; Zarus, G M

2001-12-01

189

Significance of hydrogen sulfide production in the pancreatic ?-cell.  

PubMed

Hydrogen sulfide (H(2)S) is an important signaling molecule in various mammalian cells and tissues. H(2)S is synthesized from L-cysteine and regulates several cellular and physiological phenomena (vasorelaxation, hormone secretion, and apoptosis) and multicellular events (neuromodulation and inflammatory responses). H(2)S can be produced in pancreatic ?-cells by cystathionine ?-synthase (CBS) or cystathionine ?-lyase (CSE). H(2)S inhibits insulin release and regulates ?-cell survival. We found that glucose stimulation increased CSE expression at transcript and protein levels in mouse pancreatic islets. We also found that H(2)S protects ?-cells that were chronically exposed to high glucose from apoptotic cell death. Loss of ?-cell mass and failures of ?-cell function are important in the pathogenesis and/or progression of diabetes mellitus; therefore, molecular analyses of the mechanisms of H(2)S production and its protective effects on ?-cells may lead to new insights into diabetes mellitus. PMID:21512302

Taniguchi, Shigeki; Niki, Ichiro

2011-04-21

190

Robustness of the microaerobic removal of hydrogen sulfide from biogas.  

PubMed

Several disturbances presented in full-scale digesters can potentially affect the efficiency of the microaerobic removal process. This study evaluates the variation of the sulfur load and the performance of the system in situations of oxygen lack or excess and after normal rates are recovered. The process was shown to recover from oxygen lack or excess within 28 h when the original conditions were restored in a pilot-plant digester of 200 L treating sewage sludge with HRT of 20 days. The decrease of the sulfur load to the digester did not affect the biogas composition in the short-term and when oxygen rate was reduced to adjust to the lower hydrogen sulfide production, the removal proceeded normally with a lower unemployed oxygen amount. The digester opening to remove accumulated sulfur in the headspace did not alter process performance once the microaerobic removal was restarted. PMID:22466581

Díaz, I; Fdz-Polanco, M

2012-01-01

191

Selective Catalytic Oxidation of Hydrogen Sulfide--Systems Analysis for IGCC Applications  

SciTech Connect

Selective catalytic oxidation of hydrogen sulfide (SCOHS) has been evaluated conceptually for IGCC applications, and the theoretical limits of reaction performance, process performance, and economic potential in IGCC have been estimated. Syngas conditions that have high partial pressures of total sulfur result in substantial liquid sulfur retention within the catalyst bed, with relatively complex processing being required. Applications that have much lower total sulfur partial pressure in the process gas might permit SCOHS operation under conditions where little liquid sulfur is retained in the catalyst, reducing the processing complexity and possibly improving the desulfurization performance. The results from our recent IGCC process evaluations using the SCOHS technology and conventional syngas cleaning are presented, and alternative SCOHS process configurations and applications that provide greater performance and cost potential are identified.

Newby, R.A.; Keairns, D.L.; Alvin, M.A.

2006-09-01

192

Structure-Sensitive Catalytic Dehydrogenation of Hydrogen Donors over Iron Sulfides: New Methods for Increasing Coal Depolymerization under Mild Conditions. Final Report, July 1, 1983-December 31, 1984.  

National Technical Information Service (NTIS)

The objectives of this project were to examine the mechanisms of hydrogen sulfides in order to explore the conditions for enhancement of in situ hydrogen sulfide production in coal and to study the conditions for stabilizing iron sulfide structures under ...

G. V. Smith J. B. Phillips

1985-01-01

193

Methods for producing hydrogen (BI) sulfide and/or removing metals  

DOEpatents

The present invention is a process wherein sulfide production by bacteria is efficiently turned on and off, using pH adjustment. The adjustment of pH impacts sulfide production by bacteria by altering the relative amounts of H.sub.2 S and HS-- in solution and thereby control the inhibition of the bacterial metabolism that produces sulfide. This process can be used to make a bioreactor produce sulfide "on-demand" so that the production of sulfide can be matched to its use as a metal precipitation reagent. The present invention is of significance because it enables the use of a biological reactor, a cost effective sulfide production system, by making the biological reactor produce hydrogen sulfide "on demand", and therefore responsive to production schedules, waste stream generation rate, and health and safety requirements/goals.

Truex, Michael J [Richland, WA; Peyton, Brent M [Pullman, WA; Toth, James J [Kennewick, WA

2002-05-14

194

Production of Hydrogen Sulfide by Streptomycetes and Methods for its Detection  

PubMed Central

The ability of streptomycetes to produce hydrogen sulfide is generally used for taxonomic purposes. It was found that the previously used method, the blackening of Peptone Iron Agar, does not clearly indicate formation of hydrogen sulfide. It was shown that the blackening of a lead acetate strip is the most accurate indicator for H2S-producing streptomycetes. A great variety of organic and inorganic sulfur compounds were examined and compared, and the choice of the most suitable sulfur source and method for the detection of hydrogen sulfide is discussed.

Kuster, E.; Williams, S. T.

1964-01-01

195

Interaction of beggiatoa and rice plant: detoxification of hydrogen sulfide in the rice rhizosphere.  

PubMed

Beggiatoa was obtained from six habitats, including four water-saturated soils from rice fields. The isolate of Beggiatoa from Bernard clay, when reinoculated into soil treatments from pure culture, significantly reduced hydrogen sulfide levels in soils and increased oxygen release from rice plants. Rice plants significantly increased Beggiatoa survival in flooded soils. Some hydrogen sulfide was necessary for survival of the Bernard clay isolate; high concentrations of hydrogen sulfide killed the Bernard clay isolate but were tolerated by a Crowley silt loam isolate from Eagle Lake, Texas. The results suggest that Beggiatoa may be an element of wetlands plant ecosystems. PMID:17844038

Joshi, M M; Hollis, J P

1977-01-14

196

Metal?organic frameworks for the storage and delivery of biologically active hydrogen sulfide  

SciTech Connect

Hydrogen sulfide is an extremely toxic gas that is also of great interest for biological applications when delivered in the correct amount and at the desired rate. Here we show that the highly porous metal-organic frameworks with the CPO-27 structure can bind the hydrogen sulfide relatively strongly, allowing the storage of the gas for at least several months. Delivered gas is biologically active in preliminary vasodilation studies of porcine arteries, and the structure of the hydrogen sulfide molecules inside the framework has been elucidated using a combination of powder X-ray diffraction and pair distribution function analysis.

Allan, Phoebe K.; Wheatley, Paul S.; Aldous, David; Mohideen, M. Infas; Tang, Chiu; Hriljac, Joseph A.; Megson, Ian L.; Chapman, Karena W.; De Weireld, Guy; Vaesen, Sebastian; Morris, Russell E. (St Andrews)

2012-04-02

197

Process for removal of carbonyl sulfide in liquified hydrocarbon gases with absorption of acid gases  

SciTech Connect

Liquified hydrocarbon gases containing at least carbonyl sulfide as an impurity are purified by intimately mixing the liquified hydrocarbon gas with an aqueous absorbent for hydrogen sulfide in a hydrolysis zone maintained at a temperature and a pressure sufficient to maintain the liquified hydrocarbon gas in the liquid state and hydrolyze the carbonyl sulfide to hydrogen sulfide and carbon dioxide. The liquified hydrocarbon gas containing at least a portion of the formed carbonyl sulfide and carbon dioxide is separated from the liquid absorbent and passed to an absorption zone where it is contacted with a liquid hydrogen sulfide absorbent where at least the formed hydrogen sulfide is separated from the liquified petroleum gas. A stage of absorption of at least hydrogen sulfide may proceed mixing of the liquified hydrocarbon gas with the absorbent in the hydrolysis reaction zone. The absorbent employed does not combine irreversibly with carbonyl sulfide, hydrogen sulfide, and carbon dioxide, and preferably is an aqueous solution of diethanolamine.

Beavon, D.K.; Mackles, M.

1980-11-11

198

Fractional crystallization of anhydrous sulfide liquid in the system Fe-Ni-Cu-S, with application to magmatic sulfide deposits  

Microsoft Academic Search

Phase relations for coexisting monosulfide solid solution [(Fe,Ni)] 1- x S; mss] and sulfide liquid have been determined in the Fe-rich portion of the anhydrous quaternary System Fe-Ni-Cu-S at 52.5 and 50.0 at% S, 850-1050°C and low pressure. Equations for the complex dependence of the mss solidus, sulfide liquidus and distribution coefficients for exchange of Ni\\/Cu and Fe\\/Cu on temperature,

Michael E. Fleet; Yuanming Pan

1994-01-01

199

A fatal case of hydrogen sulfide poisoning in a geothermal power plant.  

PubMed

An adult man entered an oil separator room to remove waste oil from a vacuum pump in a geothermal power plant. He suddenly collapsed and died soon after. Since hydrogen sulfide gas was detected in the atmosphere at the scene of the accident, poisoning by this gas was suspected and toxicological analysis of sulfide and thiosulfate in blood, brain, lung, femoral muscle was made using the extractive alkylation technique combined with gas chromatography/mass spectrometry (GC/MS). The concentrations of sulfide in these tissues were similar to those previously reported for fatal cases of hydrogen sulfide gas. The concentration of thiosulfate in the blood was at least 48 times higher than the level in control samples. Based on these results, the cause of death was attributed to hydrogen sulfide gas poisoning. PMID:9670519

Kage, S; Ito, S; Kishida, T; Kudo, K; Ikeda, N

1998-07-01

200

The Determination of Hydrogen Sulfide in Stack Gases, Iodometric Titration After Sulfite Removal.  

ERIC Educational Resources Information Center

|The determination of hydrogen sulfide in effluents from coal-fired furnaces and incinerators is complicated by the presence of sulfur oxides (which form acids). Organic compounds also may interfere with or prevent the formation of the cadmium sulfide precipitate or give false positive results because of reaction with iodine. The report presents a…

Robles, E. G.

201

Mechanism for the hydrogen sulfide-induced growth limitation in wetland macrophytes  

Microsoft Academic Search

Hydrogen sulfide, a phytotoxin that often accumulates in anoxic marine and freshwater marsh soils, suppressed the activity of alcohol dehydrogenase (ADH), the enzyme that catalyzes the terminal step in alcoholic fermentation, in the roots of two wetland macrophytes. This inhibition of root ADH activity with increasing sulfide concentration was associated with decreases in root total adenine nucleotide pool (ATP +

MARGUERITE S. KOCH; IRVING A. MENDELSSOHN; KAREN L. MCKEE

1990-01-01

202

Impaired detoxication of hydrogen sulfide in ulcerative colitis?  

PubMed

Impaired butyrate oxidation and raised counts of sulfate-reducing bacteria in the colon of patients with ulcerative colitis (UC) indicate that the disease may be induced or aggravated by hydrogen sulfide toxicity. We aimed to examine enzymatic removal of H(2)S in erythrocytes and colonic mucosa from controls and patients with UC and Crohn's disease (CD). Rhodanese (RHOD) and thiol methyltransferase (TMT) activities were measured in rectal mucosa and erythrocytes, and plasma thiocyanate was determined. Four groups were analyzed: patients with UC, patients with CD, hospital controls (patients with dyspepsia or IBS), and a group of healthy volunteers. RHOD and TMT activity in rectal biopsies did not differ significantly between controls and patients with UC or CD (n=56). Control levels of RHOD were significantly higher in men than in women (212+/-25 and 132+/-14 nmol/mg/min, respectively; P<0.01). In erythrocytes (n=128) RHOD activity was significantly higher in UC patients than in hospital or volunteer controls (1.15+/-0.12 compared with 0.88+/-0.12 and 0.66+/-0.02 nmol/mg/min; P<0.05 and P<0.02, respectively). TMT activity was also significantly higher in erythrocytes from UC patients and hospital controls than volunteer controls (2.02+/-0.13 pmol/mg/min [P<0.001], 1.51+/-0.21 pmol/mg/min [P<0.05], and 1.17+/-0.18 pmol/mg/min, respectively). We found no evidence of defective enzymic detoxication of sulfide by RHOD or TMT in patients with UC or CD. PMID:17216575

Picton, R; Eggo, M C; Langman, M J S; Singh, S

2007-01-11

203

Rate controlling processes for crack growth in hydrogen sulfide for an alsl 4340 steel  

NASA Astrophysics Data System (ADS)

Parallel fracture mechanics and surface chemistry studies were carried out to develop further understanding of environment assisted subcritical crack growth in high strength steels. The kinetics of crack growth for an AISI 4340 steel (tempered at 477 K) in high purity hydrogen sulfide have been determined as a function of pressure at room temperature and as a function of temperature at hydrogen sulfide pressures of 0.133 and 2.66 kPa. The kinetics for the reactions of hydrogen sulfide with this steel and the extent of reactions were also determined. Two rate controlling processes have been identified. At the lower pressure, the rate of crack growth varies according to T1/2 and is controlled by the rate of transport of hydrogen sulfide to the crack tip. At the higher pressure, crack growth is controlled by the rate of diffusion of hydrogen into the steel ahead of the crack tip and exhibits an apparent activation energy of about 5 kJ/mol. Embrittlement results from hydrogen that is produced by the reactions of hydrogen sulfide with the steel. These reactions are extremely rapid and are limited in extent, leading to the formation of one to two layers of “sulfide” on the fracture surfaces. The crack growth results are discussed in terms of measured reaction kinetics and published data on diffusion, and in relation to models for transport- and diffusion-controlled crack growth.

Lu, M.; Pao, P. S.; Weir, T. W.; Simmons, G. W.; Wei, R. P.

1981-05-01

204

VERIFICATION OF AMBIENT MONITORING TECHNOLOGIES FOR AMMONIA AND HYDROGEN SULFIDE AT ANIMAL FEEDING OPERATIONS  

EPA Science Inventory

The increasing concentration of livestock agriculture into animal feeding operations (AFOs) has raised concerns about the environmental and potential health impact of the emissions from AFOs into the atmosphere. Gaseous ammonia (NH3) and hydrogen sulfide (H2...

205

Occupationally related hydrogen sulfide deaths in the United States from 1984 to 1994.  

PubMed

Alice Hamilton described fatal work injuries from acute hydrogen sulfide poisonings in 1925 in her book Industrial Poisons in the United States. There is no unique code for H2S poisoning in the International Classification of Diseases, 9th Revision; therefore, these deaths cannot be identified easily from vital records. We reviewed US Occupational Safety and Health Administration (OSHA) investigation records for the period 1984 to 1994 for mention of hazardous substance 1480 (hydrogen sulfide). There were 80 fatalities from hydrogen sulfide in 57 incidents, with 19 fatalities and 36 injuries among coworkers attempting to rescue fallen workers. Only 17% of the deaths were at workplaces covered by collective bargaining agreements. OSHA issued citations for violation of respiratory protection and confined space standards in 60% of the fatalities. The use of hydrogen sulfide detection equipment, air-supplied respirators, and confined space safety training would have prevented most of the fatalities. PMID:10998771

Fuller, D C; Suruda, A J

2000-09-01

206

76 FR 69136 - Hydrogen Sulfide; Community Right-to-Know Toxic Chemical Release Reporting  

Federal Register 2010, 2011, 2012, 2013

...CFR Part 372 [EPA-HQ-TRI-2009-0844; FRL-9488-5] RIN 2025-AA27 Hydrogen Sulfide; Community Right-to-Know Toxic Chemical Release Reporting AGENCY: Environmental Protection Agency (EPA). ACTION: Lifting of Administrative Stay for...

2011-11-08

207

Regulation of bacterial sulfate reduction and hydrogen sulfide fluxes in the central namibian coastal upwelling zone  

NASA Astrophysics Data System (ADS)

The coastal upwelling system off central Namibia is one of the most productive regions of the oceans and is characterized by frequently occurring shelf anoxia with severe effects for the benthic life and fisheries. We present data on water column dissolved oxygen, sulfide, nitrate and nitrite, pore water profiles for dissolved sulfide and sulfate, 35S-sulfate reduction rates, as well as bacterial counts of large sulfur bacteria from 20 stations across the continental shelf and slope. The stations covered two transects and included the inner shelf with its anoxic and extremely oxygen-depleted bottom waters, the oxygen minimum zone on the continental slope, and the lower continental slope below the oxygen minimum zone. High concentrations of dissolved sulfide, up to 22 mM, in the near-surface sediments of the inner shelf result from extremely high rates of bacterial sulfate reduction and the low capacity to oxidize and trap sulfide. The inner shelf break marks the seaward border of sulfidic bottom waters, and separates two different regimes of bacterial sulfate reduction. In the sulfidic bottom waters on the shelf, up to 55% of sulfide oxidation is mediated by the large nitrate-storing sulfur bacteria, Thiomargarita spp. The filamentous relatives Beggiatoa spp. occupy low-O 2 bottom waters on the outer shelf. Sulfide oxidation on the slope is apparently not mediated by the large sulfur bacteria. The data demonstrate the importance of large sulfur bacteria, which live close to the sediment-water interface and reduce the hydrogen sulfide flux to the water column. Modeling of pore water sulfide concentration profiles indicates that sulfide produced by bacterial sulfate reduction in the uppermost 16 cm of sediment is sufficient to account for the total flux of hydrogen sulfide to the water column. However, the total pool of hydrogen sulfide in the water column is too large to be explained by steady state diffusion across the sediment-water interface. Episodic advection of hydrogen sulfide, possibly triggered by methane eruptions, may contribute to hydrogen sulfide in the water column.

Brüchert, Volker; Jørgensen, Bo Barker; Neumann, Kirsten; Riechmann, Daniela; Schlösser, Manfred; Schulz, Heide

2003-12-01

208

Hydrogen sulfide mitigates matrix metalloproteinase-9 activity and neurovascular permeability in hyperhomocysteinemic mice  

Microsoft Academic Search

An elevated level of homocysteine (Hcy), known as hyperhomocysteinemia (HHcy), was associated with neurovascular diseases. At physiological levels, hydrogen sulfide (H2S) protected the neurovascular system. Because Hcy was also a precursor of hydrogen sulfide (H2S), we sought to test whether the H2S protected the brain during HHcy. Cystathionine-?-synthase heterozygous (CBS+\\/?) and wild type (WT) mice were supplemented with or without

Neetu Tyagi; Srikanth Givvimani; Natia Qipshidze; Soumi Kundu; Shray Kapoor; Jonathan C. Vacek; Suresh C. Tyagi

2010-01-01

209

Ways to improve the removal of hydrogen sulfide from coke-oven gas  

Microsoft Academic Search

Our calculations showed that, if the gas temperatures ahead of the scrubbers were reuced to 30°C and 300 to 400 liters\\/h of concentrated ammonia water were added to the circuit, the degree of hydrogen sulfide absorption could be brought to 58 to 65%, i.e., the hydrogen sulfide content in the return gas would be less than 2.5 g\\/m³. All the

M. D. Kuznetsov; Lyannaya; E. P. Ignatova; I. I. Zbykovskii; Ya. I. Shukh; I. M. Andreiko; I. Ya. Garkushenko

1979-01-01

210

Hydrogen sulfide impairs keratinocyte cell growth and adhesion inhibiting mitogen-activated protein kinase signaling  

Microsoft Academic Search

The effects of exogenous hydrogen sulfide (H2S) on normal skin-derived immortalized human keratinocytes have been investigated in detail. We show in vitro that exogenous hydrogen sulfide reduces clonal growth, cell proliferation and cell adhesion of human keratinocytes. H2S, in fact, decreases the frequency of the putative keratinocyte stem cell subpopulation in culture, consequently affecting clonal growth, and impairs cell proliferation

Giuliana Gobbi; Francesca Ricci; Chiara Malinverno; Cecilia Carubbi; Maurizia Pambianco; Giuseppe de Panfilis; Marco Vitale; Prisco Mirandola

2009-01-01

211

Process for removal of carbonyl sulfide in liquified hydrocarbon gases with absorption of acid gases  

Microsoft Academic Search

Liquified hydrocarbon gases containing at least carbonyl sulfide as an impurity are purified by intimately mixing the liquified hydrocarbon gas with an aqueous absorbent for hydrogen sulfide in a hydrolysis zone maintained at a temperature and a pressure sufficient to maintain the liquified hydrocarbon gas in the liquid state and hydrolyze the carbonyl sulfide to hydrogen sulfide and carbon dioxide.

D. K. Beavon; M. Mackles

1980-01-01

212

Microbial control of hydrogen sulfide production in a porous medium  

Microsoft Academic Search

The ability of a sulfide- and glutaraldehyde-tolerant strain ofThiobacillus denitrificans (strain F) to control sulfide production in an experimental system of cores and formation water from the Redfield, Iowa natural\\u000a gas storage facility was investigated. A stable, sulfide-producing biofilm was established in two separate core systems, one\\u000a of which was inoculated with strain F, and the other core system (control)

Michael J. McInerney; Neil Q. Wofford; Kerry L. Sublette

1996-01-01

213

Novel Composite Hydrogen-Permeable Membranes for Nonthermal Plasma Reactors for the Decomposition of Hydrogen Sulfide  

SciTech Connect

The goal of this experimental project was to design and fabricate a reactor and membrane test cell to dissociate hydrogen sulfide (H{sub 2}S) in a nonthermal plasma and to recover hydrogen (H{sub 2}) through a superpermeable multi-layer membrane. Superpermeability of hydrogen atoms (H) has been reported by some researchers using membranes made of Group V transition metals (niobium, tantalum, vanadium, and their alloys), but it was not achieved at the moderate pressure conditions used in this study. However, H{sub 2}S was successfully decomposed at energy efficiencies higher than any other reports for the high H{sub 2}S concentration and moderate pressures (corresponding to high reactor throughputs) used in this study.

Morris Argyle; John Ackerman; Suresh Muknahallipatna; Jerry Hamann; Stanislaw Legowski; Gui-Bing Zhao; Sanil John; Ji-Jun Zhang; Linna Wang

2007-09-30

214

Hydrogen Sulfide Induced Disruption of Na+ Homeostasis in the Cortex  

PubMed Central

Maintenance of ionic balance is essential for neuronal functioning. Hydrogen sulfide (H2S), a known toxic environmental gaseous pollutant, has been recently recognized as a gasotransmitter involved in numerous biological processes and is believed to play an important role in the neural activities under both physiological and pathological conditions. However, it is unclear if it plays any role in maintenance of ionic homeostasis in the brain under physiological/pathophysiological conditions. Here, we report by directly measuring Na+ activity using Na+ selective electrodes in mouse cortical slices that H2S donor sodium hydrosulfide (NaHS) increased Na+ influx in a concentration-dependent manner. This effect could be partially blocked by either Na+ channel blocker or N-methyl-D-aspartate receptor (NMDAR) blocker alone or almost completely abolished by coapplication of both blockers but not by non-NMDAR blocker. These data suggest that increased H2S in pathophysiological conditions, e.g., hypoxia/ischemia, potentially causes a disruption of ionic homeostasis by massive Na+ influx through Na+ channels and NMDARs, thus injuring neural functions. Activation of delta-opioid receptors (DOR), which reduces Na+ currents/influx in normoxia, had no effect on H2S-induced Na+ influx, suggesting that H2S-induced disruption of Na+ homeostasis is resistant to DOR regulation and may play a major role in neuronal injury in pathophysiological conditions, e.g., hypoxia/ischemia.

Chao, Dongman; He, Xiaozhou; Yang, Yilin; Balboni, Gianfranco; Salvadori, Severo; Kim, Dong H.; Xia, Ying

2012-01-01

215

A novel sorbent tube for ambient hydrogen sulfide determination.  

PubMed

A novel tubular device has been developed for hydrogen sulfide determination in air. Several substrates such as commercial silica gel and alumina TLC plates, silica gel powder, alumina, CaSO(4), CaCO(3), BaSO(4), MgO, chalk, alpha-cellulose and ethyl cellulose were tested as solid substrates. 30-70-mesh silica gel was finally employed in glass tubes of 4.0 mm internal diameter. Silica gel is treated with 0.5 M aqueous CdCl(2) solution, dried, filled into the glass tube and sample gas is passed through the device using nitrogen as the carrier gas where 70% relative humidity is employed. The analyte reacts with the solid substrate to form a luminescent spot whose length in the tube is measured and correlated to concentration. The flow rate was 68 ml min(-1). The analytical system is linear in the range of 0.2-1.3 ppm H(2)S for the specified conditions. The prepared devices are stable at least for 3 months prior to sampling; and after sampling, the luminescing spot is stable also at least for 3 months. PMID:18967360

Volkan, M; Eroglu, T; Eroglu, A E; Ataman, O Y; Mark, H B

1998-11-01

216

Carbamoylation abrogates the antioxidant potential of hydrogen sulfide.  

PubMed

Hydrogen sulfide (H2S) has been identified as the third gasotransmitter. Beside its role as signaling molecule in the cardiovascular and nervous system the antioxidant and cyto-protective properties of H2S have gained much attention. In the present study we show that cyanate, an uremic toxin which is found in abundant concentration in sera of patients suffering from chronic kidney disease (CKD), can abrogate the antioxidant and cytoprotective activity of H2S via S-carbamoylation reaction, a reaction that previously has only been shown to have a physiological effect on cysteine groups, but not on H2S. Carbamoylation strongly inhibited the free radical scavenging (ABTS(+) and alkylperoxyl ROO) properties of H2S. The extent of intracellular ROS formation induced by ROO was diminished by H2S whereas carbamoylation counteracted the protective effect. Reagent HOCl was rapidly inactivated by H2S in contrast to the carbamoylated compound. Protein modification by HOCl was inhibited by H2S but carbamoylation significantly reduced the effect. Thus, S-carbamoylation of low molecular weight thiols by abrogating their antioxidant potential may contribute to the higher oxidative stress observed in CKD. PMID:23896375

Praschberger, Monika; Hermann, Marcela; Laggner, Christian; Jirovetz, Leopold; Exner, Markus; Kapiotis, Stylianos; Gmeiner, Bernhard M K; Laggner, Hilde

2013-07-26

217

Hydrogen sulfide induced disruption of Na+ homeostasis in the cortex.  

PubMed

Maintenance of ionic balance is essential for neuronal functioning. Hydrogen sulfide (H(2)S), a known toxic environmental gaseous pollutant, has been recently recognized as a gasotransmitter involved in numerous biological processes and is believed to play an important role in the neural activities under both physiological and pathological conditions. However, it is unclear if it plays any role in maintenance of ionic homeostasis in the brain under physiological/pathophysiological conditions. Here, we report by directly measuring Na(+) activity using Na(+) selective electrodes in mouse cortical slices that H(2)S donor sodium hydrosulfide (NaHS) increased Na(+) influx in a concentration-dependent manner. This effect could be partially blocked by either Na(+) channel blocker or N-methyl-D-aspartate receptor (NMDAR) blocker alone or almost completely abolished by coapplication of both blockers but not by non-NMDAR blocker. These data suggest that increased H(2)S in pathophysiological conditions, e.g., hypoxia/ischemia, potentially causes a disruption of ionic homeostasis by massive Na(+) influx through Na(+) channels and NMDARs, thus injuring neural functions. Activation of delta-opioid receptors (DOR), which reduces Na(+) currents/influx in normoxia, had no effect on H(2)S-induced Na(+) influx, suggesting that H(2)S-induced disruption of Na(+) homeostasis is resistant to DOR regulation and may play a major role in neuronal injury in pathophysiological conditions, e.g., hypoxia/ischemia. PMID:22474073

Chao, Dongman; He, Xiaozhou; Yang, Yilin; Balboni, Gianfranco; Salvadori, Severo; Kim, Dong H; Xia, Ying

2012-04-02

218

Physiological implications of hydrogen sulfide: a whiff exploration that blossomed.  

PubMed

The important life-supporting role of hydrogen sulfide (H(2)S) has evolved from bacteria to plants, invertebrates, vertebrates, and finally to mammals. Over the centuries, however, H(2)S had only been known for its toxicity and environmental hazard. Physiological importance of H(2)S has been appreciated for about a decade. It started by the discovery of endogenous H(2)S production in mammalian cells and gained momentum by typifying this gasotransmitter with a variety of physiological functions. The H(2)S-catalyzing enzymes are differentially expressed in cardiovascular, neuronal, immune, renal, respiratory, gastrointestinal, reproductive, liver, and endocrine systems and affect the functions of these systems through the production of H(2)S. The physiological functions of H(2)S are mediated by different molecular targets, such as different ion channels and signaling proteins. Alternations of H(2)S metabolism lead to an array of pathological disturbances in the form of hypertension, atherosclerosis, heart failure, diabetes, cirrhosis, inflammation, sepsis, neurodegenerative disease, erectile dysfunction, and asthma, to name a few. Many new technologies have been developed to detect endogenous H(2)S production, and novel H(2)S-delivery compounds have been invented to aid therapeutic intervention of diseases related to abnormal H(2)S metabolism. While acknowledging the challenges ahead, research on H(2)S physiology and medicine is entering an exponential exploration era. PMID:22535897

Wang, Rui

2012-04-01

219

Depolarizing actions of hydrogen sulfide on hypothalamic paraventricular nucleus neurons.  

PubMed

Hydrogen sulfide (H2S) is a novel neurotransmitter that has been shown to influence cardiovascular functions as well and corticotrophin hormone (CRH) secretion. Since the paraventricular nucleus of the hypothalamus (PVN) is a central relay center for autonomic and endocrine functions, we sought to investigate the effects of H2S on the neuronal population of the PVN. Whole cell current clamp recordings were acquired from the PVN neurons and sodium hydrosulfide hydrate (NaHS) was bath applied at various concentrations (0.1, 1, 10, and 50 mM). NaHS (1, 10, and 50 mM) elicited a concentration-response relationship from the majority of recorded neurons, with almost exclusively depolarizing effects following administration. Cells responded and recovered from NaHS administration quickly and the effects were repeatable. Input differences from baseline and during the NaHS-induced depolarization uncovered a biphasic response, implicating both a potassium and non-selective cation conductance. The results from the neuronal population of the PVN shed light on the possible physiological role that H2S has in autonomic and endocrine function. PMID:23691233

Khademullah, C Sahara; Ferguson, Alastair V

2013-05-17

220

PROVISIONAL ADVISORY LEVELS (PALs) FOR HYDROGEN SULFIDE (H2S)  

SciTech Connect

Application of PAL protocols was performed for hydrogen sulfide (H2S) as experimental data permitted. The data base includes human experimental studies, worker exposure evaluations, as well as case studies on acute and repeated exposure. The data base of animal studies is substantial covering multiple species and addressing acute, repeated, and subchronic exposure scenarios. PAL estimates were approved by the Expert Consultation Panel for Provisional Advisory Levels in November 2006. No reliable data were found on oral exposure, making it impractical to estimate PALs for drinking water. Since H2S exists as a gas, partitioning to air is likely to occur with an environmental release. H2S inhalation PAL values for 24 hr exposure are: PAL 1 = 1.2 ppm; PAL 2 = 7.0 ppm; and PAL 3 = 27 ppm; the 30-d and 90-d inhalation exposure values are: PAL 1 = 0.85 ppm and PAL 2 = 3.0 ppm. PAL 3 values for 30-d and 90-d are not recommended due to insufficient data. Long-term data were insufficient to estimate 2-year inhalation PALs.

Marshall, Thomas C [ORNL; Dorman, David [College of Veterinary Medicine, North Carolina University; Gardner, Donald [Inhalation Toxicology Associates; Adeshina, Femi [U.S. Environmental Protection Agency; Ross, Robert Hord [ORNL

2009-01-01

221

[Severe hydrogen sulfide intoxication: a pediatric case of survival].  

PubMed

We report a paediatric case of survival following severe hydrogen sulfide (H2S) gas intoxication. A 13-year-old boy was found submerged to the neck in a manure tank. He was hypothermic, unresponsive with bilateral mydriasis, and had poor oxygen saturation. After intubation, he was transferred to the paediatric intensive care unit of a tertiary care children's hospital. He developed acute respiratory distress syndrome (ARDS) requiring high frequency percussive ventilation. Cardiac evaluation was significant for myocardial infarction and left ventricular function impairment. He completely recovered from the respiratory and cardiac failure. Neurological examinations showed abnormal signals on MRI in the semi-oval center and in the frontal cortex. Follow-up detected partial impairment of axonal fibers of the right external popliteal sciatic nerve. Paediatric cases of survival after H2S intoxication have been rarely reported. Such exposures can evolve to severe ARDS and benefit from high frequency percussive ventilation. Hypothermia and other metabolic abnormalities are now better explained thanks to actual knowledge about endogenous H2S function. Lessons learned from paediatric accidents should result in better information about this threat for farmers and families living in houses with septic tanks, reducing the risk to their own and their children's safety. PMID:22305402

Claudet, I; Marcoux, M-O; Karsenty, C; Rittié, J-L; Honorat, R; Lelong-Tissier, M-C

2012-02-03

222

Microbial regulation of host hydrogen sulfide bioavailability and metabolism.  

PubMed

Hydrogen sulfide (H2S), generated through various endogenous enzymatic and nonenzymatic pathways, is emerging as a regulator of physiological and pathological events throughout the body. Bacteria in the gastrointestinal tract also produce significant amounts of H2S that regulates microflora growth and virulence responses. However, the impact of the microbiota on host global H2S bioavailability and metabolism remains unknown. To address this question, we examined H2S bioavailability in its various forms (free, acid labile, or bound sulfane sulfur), cystathionine ?-lyase (CSE) activity, and cysteine levels in tissues from germ-free versus conventionally housed mice. Free H2S levels were significantly reduced in plasma and gastrointestinal tissues of germ-free mice. Bound sulfane sulfur levels were decreased by 50-80% in germ-free mouse plasma and adipose and lung tissues. Tissue CSE activity was significantly reduced in many organs from germ-free mice, whereas tissue cysteine levels were significantly elevated compared to conventional mice. These data reveal that the microbiota profoundly regulates systemic bioavailability and metabolism of H2S. PMID:23466556

Shen, Xinggui; Carlström, Mattias; Borniquel, Sara; Jädert, Cecilia; Kevil, Christopher G; Lundberg, Jon O

2013-03-01

223

Selective Catalytic Oxidation of Hydrogen Sulfide--IGCC Applications  

SciTech Connect

Selective catalytic oxidation of hydrogen sulfide (SCOHS) to elemental sulfur using activated carbon and NETL-processed metal oxide catalyst systems has been investigated under bench-scale, simulated pressurized IGCC conditions for use in dry and humid gas cleaning process applications. For this technology to be successful, a 20% cost effective advantage and 1 percentage-point plant efficiency gain over current commercial technology, and <10-15 ppm total gas phase sulfur release into the effluent gas stream must be demonstrated. The results of our bench-scale catalyst/sorbent desulfurization and regeneration efforts for both bulk and polishing sulfur removal indicate that direct selective catalytic oxidation of H2S to elemental sulfur utilizing current activated carbon systems occurs only under conditions of low syngas temperature (<150°C), and in syngas effluent streams containing a low water and CO content. Thus the SCOHS desulfurization process is considered to be only potentially feasible for use in dry gas cleaning conditions for IGCC applications where syngas-CO is shifted to CO2, and regeneration of the catalyst occurs through heating in warm CO2, with simultaneous CO2 sequestration. SCOHS is not considered as a candidate desulfurization approach for use in humid IGCC gas cleaning applications.

Alvin, M.A.; Stevens, R.W.; Newby, R.A.; Keairns, D.L.

2006-09-01

224

Physiological and pharmacological features of the novel gasotransmitter: Hydrogen sulfide  

PubMed Central

Hydrogen sulfide (H2S) has been known for hundreds of years because of its poisoning effect. Once the basal bio-production became evident its pathophysiological role started to be investigated in depth. H2S is a gas that can be formed by the action of two enzymes, cystathionine gamma-lyase and cystathionine beta-synthase, both involved in the metabolism of cysteine. It has several features in common with the other two well known “gasotransmitters” (nitric oxide and carbon monoxide) in the biological systems. These three gasses share some biological targets; however, they also have dissimilarities. For instance, the three gases target heme-proteins and open KATP channels; H2S as NO is an antioxidant, but in contrast to the latter molecule, H2S does not directly form radicals. In the last years H2S has been implicated in several physiological and pathophysiological processes such as long term synaptic potentiation, vasorelaxation, pro- and anti-inflammatory conditions, cardiac inotropism regulation, cardioprotection, and several other physiological mechanisms. We will focus on the biological role of H2S as a molecule able to trigger cell signaling. Our attention will be particularly devoted on the effects in cardiovascular system and in cardioprotection. We will also provide available information on H2S-donating drugs which have so far been tested in order to conjugate the beneficial effect of H2S with other pharmaceutical properties.

Mancardi, Daniele; Penna, Claudia; Merlino, Annalisa; Del Soldato, Piero; Wink, David A.; Pagliaro, Pasquale

2012-01-01

225

Alleviation of chromium toxicity by hydrogen sulfide in barley.  

PubMed

A hydroponic experiment was carried out to examine the effect of hydrogen sulfide (H2 S) in alleviating chromium (Cr) stress in barley. A 2-factorial design with 6 replications was selected, including 3 levels of NaHS (0??M, 100??M, and 200??M) and 2 levels of Cr (0??M and 100??M) as treatments. The results showed that NaHS addition enhances plant growth and photosynthesis slightly compared with the control. Moreover, NaHS alleviated the inhibition in plant growth and photosynthesis by Cr stress. Higher levels of NaHS exhibited more pronounced effects in reducing Cr concentrations in roots, shoots, and leaves. Ultrastructural examination of plant cells supported the facts by indication of visible alleviation of cell disorders in both root and leaf with exogenous application of NaHS. An increased number of plastoglobuli, disintegration, and disappearance of thylakoid membranes and starch granules were visualized inside the chloroplast of Cr-stressed plants. Starch accumulation in the chloroplasts was also noticed in the Cr-treated cells, with the effect being much less in Cr?+?NaHS-treated plants. Hence, it is concluded that H2 S produced from NaHS can improve plant tolerance under Cr stress. Environ Toxicol Chem 2013;32:2234-2239. © 2013 SETAC. PMID:23775579

Ali, Shafaqat; Farooq, Muhammad Ahsan; Hussain, Sabir; Yasmeen, Tahira; Abbasi, G H; Zhang, Guoping

2013-08-21

226

Can Hydrogen Sulfide Gas Be a Biosignature in a Habitable Exoplanet?  

NASA Astrophysics Data System (ADS)

A group of microorganisms can disproportionate sulfite and elemental sulfur into sulfide and sulfate to obtain energy for a living. We explore if the sulfide produced by microorganisms can alter the atmospheric composition to manifest in the spectrum of a habitable exoplanet. We consider a dry (i.e., limited ocean cover) habitable planet of Earth size and mass, orbiting a Sun-like star. As on Earth, volcanoes release sulfur as sulfur dioxide and hydrogen sulfide, but the volcanic production of hydrogen sulfide is limited by the scarcity of water. In the meantime, in our scenario, microbes can flourish in the ocean and effectively make use of the energy gained from the sulfur disproportion and release sulfide as the metabolic byproduct. The metabolic sulfur disproportion can enhance the overall outgassing rate of hydrogen sulfide by nearly one order of magnitude over the non-biological emission. To study the atmospheric response to this enhancement, we build a one-dimensional chemical transport model that treats all O, H and S bearing species and the relevant photochemical and chemical reactions. The vertical transport is approximated with the eddy diffusion. We also consider the formation and the sedimentation of elemental sulfur aerosols and sulfate aerosols in the atmosphere and explore the effect of aerosol particle size on the chemistry and the radiative transfer. To establish hydrogen sulfide as a biosignature, we need to understand the atmospheric response to the sulfide outgassing, the spectral features of hydrogen sulfide and its photochemical products, and the volcanic release of H2S. The current work will address the first two problems, and the main uncertainty will remain at the possible false positives due to the volcanism.

Hu, Renyu; Seager, S.; Bains, W.

2011-05-01

227

Microbial control of the production of hydrogen sulfide by sulfate-reducing bacteria.  

PubMed

A sulfide-resistant ctrain of Thiobacillus denitrificans, strain F, prevented the accumulation of sulfide by Desulfovibrio desulfuricans when both organisms were grown in liquid medium or in Berea sandstone cores. The wild-type strain of T. denitrificans did not prevent the accumulation of sulfide produced by D. desulfuricans. Strain F also prevented the accumulation of sulfide by a mixed population of sulfate-reducing bacteria enriched from an oil field brine. Fermentation balances showed that strain F stoichiometrically oxidized the sulfide produced by D. desulfuricans and the oil field brine enrichment to sulfate. These data suggest that strain F would be effective in controlling sulfide production in oil reservoirs and other environments. PMID:18592547

Montgomery, A D; McLnerney, M J; Sublette, K L

1990-03-01

228

Evolution of hydrogen during the photolysis of aqueous solutions of sulfide and sulfite ions sensitized by cadmium sulfide  

SciTech Connect

One of the problems associated with the photochemical utilization of solar energy is the decomposition of ecologically harmful industrial waste products with the formation of harmless and even useful products. A number of publication describing the investigation of the sensitized photolysis of alkaline solutions of sulfide and sulfite ions with the use of cadmium sulfide as a sensitizer have appeared in the last few years. The photolysis of such systems is accompanied by the formation of hydrogen. In this report the authors describe experiments on the optimization of the conditions for the photolysis of the compounds indicated, and the authors compare our results with data on the photolysis of methanol with the use of the same semiconductor sensitizers. In all the experiments the quantum yield of the formation of hydrogen Phi(H), i.e., 2Phi(H/sub 2/), served as the quantitative characteristic of the photolysis process.

Sinitsyna, Z.A.; Kiryukhin, Yu.I.; Belova, I.D.; Roginskaya, Yu.E.; Bagdasar'yan, Kh.S.

1987-05-01

229

Hydrogen sulfide impairs glucose utilization and increases gluconeogenesis in hepatocytes.  

PubMed

Mounting evidence has established hydrogen sulfide (H(2)S) as an important gasotransmitter with multifaceted physiological functions. The aim of the present study was to investigate the role of H(2)S on glucose utilization, glycogen synthesis, as well as gluconeogenesis in both HepG(2) cells and primary mouse hepatocytes. Incubation with NaHS (a H(2)S donor) impaired glucose uptake and glycogen storage in HepG(2) cells via decreasing glucokinase activity. Adenovirus-mediated cystathionine ?-lyase (CSE) overexpression increased endogenous H(2)S production and lowered glycogen content in HepG(2) cells. Glycogen content was significantly higher in liver tissues from CSE knockout (KO) mice compared to that from wild type (WT) mice in fed condition. Glucose consumption was less in primarily cultured hepatocytes isolated from WT mice than those from CSE KO mice, but more glucose was produced by hepatocytes via gluconeogenesis and glycogenolysis pathways in WT mice than in CSE KO mice. NaHS treatment reduced the phosphorylation of AMP-activated protein kinase, whereas stimulation of AMP-activated protein kinase by 5-aminoimidazole-4-carboxamide-1-?-d-ribofuranoside reversed H(2)S-impaired glucose uptake. H(2)S-increased glucose production was likely through increased phosphoenolpyruvate carboxykinase activity. In addition, insulin at the physiological range inhibited CSE expression, and H(2)S decreased insulin-stimulated phosphorylation of Akt in HepG(2) cells. CSE expression was increased, however, in insulin-resistant state induced by exposing cells to high levels of insulin (500 nm) and glucose (33 mm) for 24 h. Taken together, these data suggest that the interaction of H(2)S and insulin in liver plays a pivotal role in regulating insulin sensitivity and glucose metabolism. PMID:23183179

Zhang, Ling; Yang, Guangdong; Untereiner, Ashley; Ju, Youngjun; Wu, Lingyun; Wang, Rui

2012-11-26

230

Eukaryotic and prokaryotic contributions to colonic hydrogen sulfide synthesis.  

PubMed

Hydrogen sulfide (H(2)S) is an important modulator of many aspects of digestive function, both in health and disease. Colonic tissue H(2)S synthesis increases markedly during injury and inflammation and appears to contribute to resolution. Some of the bacteria residing in the colon can also produce H(2)S. The extent to which bacterial H(2)S synthesis contributes to what is measured as colonic H(2)S synthesis is not clear. Using conventional and germ-free mice, we have delineated the eukaryotic vs. prokaryotic contributions to colonic H(2)S synthesis, both in healthy and colitic mice. Colonic tissue H(2)S production is entirely dependent on the presence of the cofactor pyridoxal 5'-phosphate (vitamin B(6)), while bacterial H(2)S synthesis appears to occur independent of this cofactor. As expected, approximately one-half of the H(2)S produced by feces is derived from eukaryotic cells. While colonic H(2)S synthesis is markedly increased when the tissue is inflamed, and, in proportion to the extent of inflammation, fecal H(2)S synthesis does not change and tissue granulocytes do not appear to be the source of the elevated H(2)S production. Rats fed a B vitamin-deficient diet for 6 wk exhibited significantly diminished colonic H(2)S synthesis, but fecal H(2)S synthesis was not different from that of rats on the control diet. Our results demonstrate that H(2)S production by colonic bacteria does not contribute significantly to what is measured as colonic tissue H(2)S production, using the acetate trapping assay system employed in this study. PMID:21474649

Flannigan, Kyle L; McCoy, Kathy D; Wallace, John L

2011-04-07

231

Hydrogen sulfide activates Ca²? sparks to induce cerebral arteriole dilatation.  

PubMed

Hydrogen sulfide (H?S) is a gaseous vasodilator produced by endothelial cells. Mechanisms by which H?S induces vasodilatation are unclear. We tested the hypothesis that H?S dilates cerebral arterioles by modulating local and global intracellular Ca²? signals in smooth muscle cells. High-speed confocal imaging revealed that Na?S, an H?S donor, increased Ca²? spark frequency ?1.43-fold and decreased global intracellular Ca²? concentration ([Ca²?]i) by ?37 nM in smooth muscle cells of intact piglet cerebral arterioles. In contrast, H?S did not alter Ca²? wave frequency. In voltage-clamped (-40 mV) cells, H?S increased the frequency of iberiotoxin-sensitive, Ca²? spark-induced transient Ca²?-activated K? (KCa) currents ?1.83-fold, but did not alter the amplitude of these events. H?S did not alter the activity of single KCa channels recorded in the absence of Ca²? sparks in arteriole smooth muscle cells. H?S increased SR Ca²? load ([Ca²?]SR), measured as caffeine (10 and 20mM)-induced [Ca²?]i transients, ?1.5-fold. H?S hyperpolarized (by ?18 mV) and dilated pressurized (40 mmHg) cerebral arterioles. Iberiotoxin, a KCa channel blocker, reduced H?S-induced hyperpolarization by ?51%. Iberiotoxin and ryanodine, a ryanodine receptor channel inhibitor, reduced H?S-induced vasodilatation by ?38 and ?37%, respectively. In summary, our data indicate that H?S elevates [Ca²?]SR, leading to Ca²? spark activation in cerebral arteriole smooth muscle cells. The subsequent elevation in transient KCa current frequency leads to membrane hyperpolarization, a reduction in global [Ca²?]i and vasodilatation. PMID:22508960

Liang, Guo Hua; Xi, Qi; Leffler, Charles W; Jaggar, Jonathan H

2012-04-16

232

Hydrogen sulfide inhibits preoptic prostaglandin E2 production during endotoxemia.  

PubMed

Hydrogen sulfide (H(2)S) is a gaseous neuromodulator endogenously produced in the brain by the enzyme cystathionine ?-synthase (CBS). We tested the hypothesis that H(2)S acts within the anteroventral preoptic region of the hypothalamus (AVPO) modulating the production of prostaglandin (PG) E(2) (the proximal mediator of fever) and cyclic AMP (cAMP). To this end, we recorded deep body temperature (Tb) of rats before and after pharmacological modulation of the CBS-H(2)S system combined or not with lipopolysaccharide (LPS) exposure, and measured the levels of H(2)S, cAMP, and PGE(2) in the AVPO during systemic inflammation. Intracerebroventricular (icv) microinjection of aminooxyacetate (AOA, a CBS inhibitor; 100 pmol) did not affect basal PGE(2) production and Tb, but enhanced LPS-induced PGE(2) production and fever, indicating that endogenous H(2)S plays an antipyretic role. In agreement, icv microinjection of a H(2)S donor (Na(2)S; 260 nmol) reduced the LPS-induced PGE(2) production and fever. Interestingly, we observed that the AVPO levels of H(2)S were decreased following the immunoinflammatory challenge. Furthermore, fever was associated with decreased levels of AVPO cAMP and increased levels of AVPO PGE(2). The LPS-induced decreased levels of cAMP were reduced to a lesser extent by the H(2)S donor. The LPS-induced PGE(2) production was potentiated by AOA (the CBS inhibitor) and inhibited by the H(2)S donor. Our data are consistent with the notion that the gaseous messenger H(2)S synthesis is downregulated during endotoxemia favoring PGE(2) synthesis and lowering cAMP levels in the preoptic hypothalamus. PMID:23153577

Kwiatkoski, Marcelo; Soriano, Renato N; Araujo, Rebeca M; Azevedo, Leopoldo U; Batalhao, Marcelo E; Francescato, Heloísa D C; Coimbra, Terezila M; Carnio, Evelin C; Branco, Luiz G S

2012-11-12

233

Intermittent control procedures for the Geysers hydrogen sulfide emission abatement  

SciTech Connect

Pacific Gas and Electric Company (PG and E) operates the world's largest geothermal steam electric power generation facility, currently about 1.140 megawatts (Mw). This facility is located about 80 miles north of San Francisco, California and is within a region referred to as the Known Geothermal Resource Area (KGRA). Pollutants resulting from this method of electric power generation are due to impurities in the geothermal steam. A major contaminate in the steam is hydrogen sulfide (H/sub 2/S), a regulated pollutant in California. The ambient air quality standard (AAQS) for this pollutant in California is 0.03 parts per million (ppM) averaged over one hour. H/sub 2/S is an invisible, unpleasant smelling gas present in varying concentrations in the geothermal steam. Its odor has been compared to the smell of rotten eggs. Since PG and E is increasingly relying on this source of electrical power generation, it has committed millions of dollars to the development, testing, acquisition, and installation of abatement equipment to reduce H/sub 2/S emissions during the past ten years. In order to reduce the number of exceeds of the AAQS during this developmental period, a predictive model was needed for interim abatement purposes. Most of the high hourly H/sub 2/S values occur with meteorological conditions having poor ventilation resulting from a combination of low wind speed and reduced mixing layer depths. This weather condition is most common during the months of June through October in California. A predictive model was developed from three years of hourly H/sub 2/S measurements of 0.03 ppM or greater in populated areas downwind of the generation facility and from observations of associated meteorological data.

Buick, B.D.; Mooney, M.L.

1984-01-01

234

Hydrogen sulfide mitigates transition from compensatory hypertrophy to heart failure  

PubMed Central

We reported previously that although there is disruption of coordinated cardiac hypertrophy and angiogenesis in transition to heart failure, matrix metalloproteinase (MMP)-9 induced antiangiogenic factors play a vital role in this process. Previous studies have shown the cardioprotective role of hydrogen sulfide (H2S) in various cardiac diseases, but its role during transition from compensatory hypertrophy to heart failure is yet to be unveiled. We hypothesize that H2S induces MMP-2 activation and inhibits MMP-9 activation, thus promoting angiogenesis, and mitigates transition from compensatory cardiac hypertrophy to heart failure. To verify this, aortic banding (AB) was created to mimic pressure overload in wild-type (WT) mice, which were treated with sodium hydrosulfide (NaHS, H2S donor) in drinking water and compared with untreated control mice. Mice were studied at 3 and 8 wk. In the NaHS-treated AB 8 wk group, the expression of MMP-2, CD31, and VEGF was increased while the expression of MMP-9, endostatin, angiostatin, and tissue inhibitor of matrix metalloproteinase (TIMP)-3 was decreased compared with untreated control mice. There was significant reduction in fibrosis in NaHS-treated groups. Echocardiograph and pressure-volume data revealed improvement of cardiac function in NaHS-treated groups over untreated controls. These results show that H2S by inducing MMP-2 promotes VEGF synthesis and angiogenesis while it suppresses MMP-9 and TIMP-3 levels, inhibits antiangiogenic factors, reduces intracardiac fibrosis, and mitigates transition from compensatory hypertrophy to heart failure.

Givvimani, Srikanth; Munjal, Charu; Gargoum, Riyad; Sen, Utpal; Tyagi, Neetu; Vacek, Jonathan C.

2011-01-01

235

The phs gene and hydrogen sulfide production by Salmonella typhimurium.  

PubMed

Salmonella typhimurium produces H2S from thiosulfate or sulfite. The respective pathways for the two reductions must be distinct as mutants carrying motations in phs, chlA, and menB reduced sulfite, but not thiosulfate, to H2S, and glucose repressed the production of H2S from thiosulfate while it stimulated its production from sulfite. The phs and chlA mutants also lacked a methyl viologen-linked thiosulfate reductase activity present in anaerobically grown wild-type cultures. A number of hydroxylamine, transposon Tn10 insertion, and Mu d1(Apr lac) operon fusion mutants defective in phs were characterized. One of the hydroxylamine mutants was an amber mutant, as indicated by suppression of its mutation in a supD background. The temperature-sensitive phs mutants produced H2S and methyl viologen-linked thiosulfate reductase at 30 degrees C but not at 42 degrees C. The reductases in all such mutants grown at 30 degrees C were as thermostable as the wild-type enzyme and did not differ in electrophoretic relative mobility, suggesting that phs is not the structural gene for thiosulfate reductase. Expression of beta-galactosidase in phs::Mu d1(Apr lac) mutants was dependent on anaerobiosis and the presence of reduced sulfur. It was also strongly influenced by carbon source and growth stage. The results are consistent with a model in which the phs gene encodes a regulatory protein essential for the reduction of thiosulfate to hydrogen sulfide. PMID:3108233

Clark, M A; Barrett, E L

1987-06-01

236

Crosstalk between hydrogen sulfide and nitric oxide in endothelial cells.  

PubMed

Hydrogen sulfide (H2 S) and nitric oxide (NO) are major gasotransmitters produced in endothelial cells (ECs), contributing to the regulation of vascular contractility and structural integrity. Their interaction at different levels would have a profound impact on angiogenesis. Here, we showed that H2 S and NO stimulated the formation of new microvessels. Incubation of human umbilical vein endothelial cells (HUVECs-926) with NaHS (a H2 S donor) stimulated the phosphorylation of endothelial NO synthase (eNOS) and enhanced NO production. H2 S had little effect on eNOS protein expression in ECs. L-cysteine, a precursor of H2 S, stimulated NO production whereas blockage of the activity of H2 S-generating enzyme, cystathionine gamma-lyase (CSE), inhibited this action. CSE knockdown inhibited, but CSE overexpression increased, NO production as well as EC proliferation. LY294002 (Akt/PI3-K inhibitor) or SB203580 (p38 MAPK inhibitor) abolished the effects of H2 S on eNOS phosphorylation, NO production, cell proliferation and tube formation. Blockade of NO production by eNOS-specific siRNA or nitro-L-arginine methyl ester (L-NAME) reversed, but eNOS overexpression potentiated, the proliferative effect of H2 S on ECs. Our results suggest that H2 S stimulates the phosphorylation of eNOS through a p38 MAPK and Akt-dependent pathway, thus increasing NO production in ECs and vascular tissues and contributing to H2 S-induced angiogenesis. PMID:23742697

Altaany, Zaid; Yang, Guangdong; Wang, Rui

2013-06-07

237

Sensory and Cognitive Effects of Acute Exposure to Hydrogen Sulfide  

PubMed Central

Background Some epidemiologic studies have reported compromised cognitive and sensory performance among individuals exposed to low concentrations of hydrogen sulfide (H2S). Objectives We hypothesized a dose–response increase in symptom severity and reduction in sensory and cognitive performance in response to controlled H2S exposures. Methods In separate exposure sessions administered in random order over three consecutive weeks, 74 healthy subjects [35 females, 39 males; mean age (± SD) = 24.7 ± 4.2; mean years of education = 16.5 ± 2.4], were exposed to 0.05, 0.5, and 5 ppm H2S. During each exposure session, subjects completed ratings and tests before H2S exposure (baseline) and during the final hour of the 2-hr exposure period. Results Dose–response reduction in air quality and increases in ratings of odor intensity, irritation, and unpleasantness were observed. Total symptom severity was not significantly elevated across any exposure condition, but anxiety symptoms were significantly greater in the 5-ppm than in the 0.05-ppm condition. No dose–response effect was observed for sensory or cognitive measures. Verbal learning was compromised during each exposure condition. Conclusions Although some symptoms increased with exposure, the magnitude of these changes was relatively minor. Increased anxiety was significantly related to ratings of irritation due to odor. Whether the effect on verbal learning represents a threshold effect of H2S or an effect due to fatigue across exposure requires further investigation. These acute effects in a healthy sample cannot be directly generalized to communities where individuals have other health conditions and concomitant exposures.

Fiedler, Nancy; Kipen, Howard; Ohman-Strickland, Pamela; Zhang, Junfeng; Weisel, Clifford; Laumbach, Robert; Kelly-McNeil, Kathie; Olejeme, Kelechi; Lioy, Paul

2008-01-01

238

Is Hydrogen Sulfide-Induced Suspended Animation General Anesthesia?  

PubMed Central

Hydrogen sulfide (H2S) depresses mitochondrial function and thereby metabolic rates in mice, purportedly resulting in a state of “suspended animation.” Volatile anesthetics also depress mitochondrial function, an effect that may contribute to their anesthetic properties. In this study, we ask whether H2S has general anesthetic properties, and by extension, whether mitochondrial effects underlie the state of anesthesia. We compared loss of righting reflex, electroencephalography, and electromyography in mice exposed to metabolically equipotent concentrations of halothane, isoflurane, sevoflurane, and H2S. We also studied combinations of H2S and anesthetics to assess additivity. Finally, the long-term effects of H2S were assessed by using the Morris water maze behavioral testing 2 to 3 weeks after exposures. Exposure to H2S decreases O2 consumption, CO2 production, and body temperature similarly to that of the general anesthetics, but fails to produce a loss of righting reflex or muscle atonia at metabolically equivalent concentrations. When combined, H2S antagonizes the metabolic effects of isoflurane, but potentiates the isoflurane-induced loss of righting reflex. We found no effect of prior H2S exposure on memory or learning. H2S (250 ppm), not itself lethal, produced delayed lethality when combined with subanesthetic concentrations of isoflurane. H2S cannot be considered a general anesthetic, despite similar metabolic suppression. Metabolic suppression, presumably via mitochondrial actions, is not sufficient to account for the hypnotic or immobilizing components of the anesthetic state. Combinations of H2S and isoflurane can be lethal, suggesting extreme care in the combination of these gases in clinical situations.

Li, Rosie Q.; McKinstry, Andrew R.; Moore, Jason T.; Caltagarone, Breanna M.; Eckenhoff, Maryellen F.; Eckenhoff, Roderic G.

2012-01-01

239

Inhibitor of hydrogen sulfide corrosion of steel based on di- and polypropylene polyamines  

Microsoft Academic Search

Several aminoimidazolines and their derivatives are produced from di-and polypropylene polyamines and higher isomeric acids.\\u000a Varying of the composition and ratio between the components of preparative form enabled us to produce a water-soluble corrosion\\u000a inhibitor that effectively protects steel against hydrogenation and corrosion in hydrogen sulfide media.

G. I. Akhmadeeva; R. N. Zagidullin

2006-01-01

240

Liquid-hydrogen-fueled passenger aircraft  

SciTech Connect

This Chinese translation discusses the idea that passenger aircraft will eventually use liquid-hydrogen fuel. There is a large reserve of hydrogen and hydrogen poses no danger to the environment. Hydrogen has high calorific value, high specific heat, low density, and low temperature. Aircraft will have to have liquid fuel tanks to carry the hydrogen and will have to be partially redesigned. Lockheed and NASA have considered such designs. A problem remains in the planning--the high cost of large extraction of liquid hydrogen.

Not Available

1986-03-11

241

Distributed fiber optic chemical sensor for hydrogen sulfide and chlorine detection  

NASA Astrophysics Data System (ADS)

Fiber optic sensors having their entire length as the sensing elements for chlorine or hydrogen sulfide are reported here. The chlorine fiber consists of a silica core and a chlorine-sensitive cladding, and the hydrogen sulfide fiber has a hydrogen sulfide sensitive cladding. Upon exposure to the corresponding challenge gas, the cladding very rapidly changes color resulting in attenuation of the light throughput of the fiber. A one-meter portion of the chlorine sensor fiber responds to 10 ppm chlorine in 20 seconds and to 1 ppm in several minutes. The attenuation after 10 minutes of exposure is very high, and is dependant on both chlorine concentration and fiber length. A ten-meter portion of the hydrogen sulfide sensor fiber responds to 100 ppm hydrogen sulfide in 30 seconds and to 10 ppm in 1 minute. The high sensitivity suggests that the propagating modes of the light interact strongly with the cladding, and that these interactions are massively increased (Beers Law) due to the extended sensor length. This approach will supersede the current method of having a collection of point-detectors to cover large areas.

Mukamal, Harold; Cordero, Steven R.; Ruiz, David; Beshay, Manal; Lieberman, Robert A.

2005-11-01

242

Regulation of [ 3 H] d Aspartate Release from Mammalian Isolated Retinae by Hydrogen Sulfide  

Microsoft Academic Search

Hydrogen sulfide (H2S), can produce pharmacological effects on neural and non-neural tissues from several mammalian species. The present study\\u000a investigates the pharmacological action of H2S, (using sodium hydrosulfide, NaHS, and\\/or sodium sulfide, Na2S as donors) on amino acid neurotransmission (using [3H] d-aspartate as a marker for glutamate) from isolated, superfused bovine and porcine retinae. Isolated neural retinae were incubated\\u000a in

Catherine A. Opere; Emmanuel M. Monjok; Kaustubh H. Kulkarni; Ya Fatou Njie; Sunny E. Ohia

2009-01-01

243

Effect of Hydrogen Sulfide on Cyclic AMP Production in Isolated Bovine and Porcine Neural Retinae  

Microsoft Academic Search

Hydrogen sulfide (H2S) has been reported to exert pharmacological effects on neural and non-neural tissues from several mammalian species. In\\u000a the present study, we examined the role of the intracellular messenger, cyclic AMP in retinal response to H2S donors, sodium hydrosulfide (NaHS) and sodium sulfide (Na2S) in cows and pigs. Isolated bovine and porcine neural retinae were incubated in oxygenated

Ya Fatou Njie-Mbye; Odelia Y. N. Bongmba; Chinwe C. Onyema; Abhishek Chitnis; Madhura Kulkarni; Catherine A. Opere; Angela M. LeDay; Sunny E. Ohia

2010-01-01

244

Analysis of hypochlorite process for removal of hydrogen sulfide from geothermal gases  

SciTech Connect

Sodium hypochlorite reacts readily with hydrogen sulfide to convert the sulfide ion into free sulfur in a neutral or acid solution and to the sulfate ion in an alkaline solution. Sodium hypochlorite can be generated on site by processing geothermal brine in electrolytic cells. An investigation to determine if this reaction could be economically used to remove hydrogen sulfide from geothermal noncondensible gases is reported. Two processes, the LO-CAT Process and the Stretford Process, were selected for comparison with the hypochlorite process. Three geothermal reservoirs were considered for evaluation: Niland KGRA, Baca KGRA, and The Geysers KGRA. Because of the wide variation in the amount of hydrogen sulfide present at The Geysers, two different gas analyses were considered for treatment. Plants were designed to process the effluent noncondensible gases from a 10 MW/sub e/ geothermal power plant. The effluent gas from each plant was to contain a maximum hydrogen sulfide concentration of 35 ppb. Capital costs were estimated for each of the processes at each of the four sites selected. Operating costs were also calculated for each of the processes at each of the sites. The results of these studies are shown.

Not Available

1980-04-01

245

Microbial control of hydrogen sulfide production in a porous medium  

SciTech Connect

The ability of a sulfide- and glutaraldehyde-tolerant strain of Thiobacillus denitrificans (strain F) to control sulfide production in an experimental system of cores and formation water from the Redfield, Iowa natural gas storage facility was investigated. A stable, sulfide-producing biofilm was established in two separate core systems, one of which was inoculated with strain F, and the other core system (control) was treated in an identical manner, but was not inoculated with strain F. When formation water with 10 mM acetate and 5mM nitrate was injected into both core systems, the effluent sulfide concentrations in the control core system ranged from 200-460 {mu}M. In the test core system inoculated with strain F, the effluent sulfide concentrations were lower, ranging from 70-110 {mu}M. In order to determine whether strain F could control sulfide production under optimal conditions for sulfate-reducing bacteria, the electron donor was changed to lactate, and inorganic nutrients (nitrogen and phosphate sources) were added to the formation water. When nutrient-supplemented formation water with 3.1 mM lactate and 10 mM nitrate was used, the effluent sulfide concentrations of the control core system initially increased to about 3800 pM, and then decreased to about 1100 {mu}M after 5 wk. However, in the test core system inoculated with strain F, the effluent sulfide concentrations were much lower, 160-330 {mu}M. Nitrate consumption (5 mM) and high concentrations (101-1011 cells/mL) of strain F were detected in the test core system. An accumulation of biomass occurred in the influent lines during 2 mo of continuous operation, but only a small increase in injection pressure was observed. These studies showed that inoculation with strain F was needed for effective control of sulfide production, and that significant plugging or loss of injectivity owing to microbial inoculation did not occur. 7 refs., 3 figs., 1 tab.

McInerney, M.J.; Wofford, N.Q. [Univ. of Oklahoma, Norman, OK (United States); Sublette, K.L. [Univ. of Tulsa, OK (United States)

1996-12-31

246

Hydrogen sulfide production and volatilization in a polymictic eutrophic saline lake, Salton Sea, California.  

PubMed

The Salton Sea is a large shallow saline lake located in southern California that is noted for high sulfate concentrations, substantial algal productivity, and very warm water column temperatures. These conditions are well-suited for sulfide production, and sulfide has been implicated in summer fish kills, although no studies have been conducted to specifically understand hydrogen sulfide production and volatilization there. Despite polymictic mixing patterns and relatively short accumulation periods, the amount of sulfide produced is comparable to meromictic lakes. Sulfide levels in the Salton Sea reached concentrations of 1.2 mmol L(-1) of total free sulfide in the hypolimnion and 5.6 mmol L(-1) in the sediment pore water. Strong winds in late July mixed H2S into the surface water, where it depleted the entire water column of dissolved oxygen and reached a concentration of 0.1 mmol L(-1). Sulfide concentrations exceeded the toxicity threshold of tilapia (Oreochromis mossambicus) and combined with strong anoxia throughout the water column, resulted in a massive fish kill. The mixing of sulfide into the surface waters also increased atmospheric H2S concentrations, reaching 1.0 micromol m(-3). The flux of sulfide from the sediment into the water column was estimated to range from 2-3 mmol m(-2) day(-1) during the winter and up to 8 mmol m(-2) day(-1) during the summer. Application of the two-layer model for volatilization indicates that up to 19 mmol m(-2) day(-1) volatilized from the surface during the mixing event. We estimate that as much as 3400 Mg year(-1) or approximately 26% of sulfide that diffused into the water column from the deepest sediments may have been volatilized to the atmosphere. PMID:18760446

Reese, Brandi Kiel; Anderson, Michael A; Amrhein, Christopher

2008-08-29

247

30 CFR 550.245 - What hydrogen sulfide (H2S) information must accompany the DPP or DOCD?  

Code of Federal Regulations, 2013 CFR

... 2013-07-01 2013-07-01 false What hydrogen sulfide (H2S) information must accompany the DPP or DOCD...Coordination Documents (docd) § 550.245 What hydrogen sulfide (H2 S) information must accompany the DPP...

2013-07-01

248

Thermally stable derivatives of propylenepolyamines as protective additives for lubricating oils used in compressors handling hydrogen sulfide-containing gas  

Microsoft Academic Search

In the transmission of natural, associated, and petroleum gases containing hydrogen sulfide, carbon dioxide, water, and other corrosive impurities, problems are created by the saturation of the compressor lubricating oil with these impurities and failure of components of the lubricating and sealing system. Hydrogen sulfide is distinguished by the greatest affinity for oil and the highest corrosivity. Its solubility in

V. A. Trofimov; I. S. Panidi; V. G. Spirkin; L. V. Leonidova; E. A. Kozhekina; M. I. Yakushkin; I. A. Makarovskii

1995-01-01

249

[Determination of the formation of hydrogen sulfide in a dry differentiating medium of the Kligler agar type].  

PubMed

The indicator system for hydrogen sulfide detection in media analogous to Kligler's agar, intended for the primary identification of enterobacteria, has been studied. The indicator system under study, in contrast to the known formulas, contains sodium metabisulfite for improving the capacity for detecting hydrogen sulfide production in bacteria which produce it in small amounts from inorganic sulfur compounds. PMID:6868888

Gorchenina, L V; Khoemnko, N A; Golubeva, I V

1983-04-01

250

Importance of Hydrogen Sulfide, Thiosulfate, and Methylmercaptan for Growth of Thiobacilli during Simulation of Concrete Corrosion  

PubMed Central

Biogenic sulfuric acid corrosion of concrete surfaces caused by thiobacilli was reproduced in simulation experiments. At 9 months after inoculation with thiobacilli, concrete blocks were severely corroded. The sulfur compounds hydrogen sulfide, thiosulfate, and methylmercaptan were tested for their corrosive action. With hydrogen sulfide, severe corrosion was noted. The flora was dominated by Thiobacillus thiooxidans. Thiosulfate led to medium corrosion and a dominance of Thiobacillus neapolitanus and Thiobacillus intermedius. Methylmercaptan resulted in negligible corrosion. A flora of heterotrophs and fungi grew on the blocks. This result implies that methylmercaptan cannot be degraded by thiobacilli.

Sand, Wolfgang

1987-01-01

251

The response of Caenorhabditis elegans to hydrogen sulfide and hydrogen cyanide.  

PubMed

Hydrogen sulfide (H2S), an endogenously produced small molecule, protects animals from various stresses. Recent studies demonstrate that animals exposed to H2S are long lived, resistant to hypoxia, and resistant to ischemia-reperfusion injury. We performed a forward genetic screen to gain insights into the molecular mechanisms Caenorhabditis elegans uses to appropriately respond to H2S. At least two distinct pathways appear to be important for this response, including the H2S-oxidation pathway and the hydrogen cyanide (HCN)-assimilation pathway. The H2S-oxidation pathway requires two distinct enzymes important for the oxidation of H2S: the sulfide:quinone reductase sqrd-1 and the dioxygenase ethe-1. The HCN-assimilation pathway requires the cysteine synthase homologs cysl-1 and cysl-2. A low dose of either H2S or HCN can activate hypoxia-inducible factor 1 (HIF-1), which is required for C. elegans to respond to either gas. sqrd-1 and cysl-2 represent the entry points in the H2S-oxidation and HCN-assimilation pathways, respectively, and expression of both of these enzymes is highly induced by HIF-1 in response to both H2S and HCN. In addition to their role in appropriately responding to H2S and HCN, we found that cysl-1 and cysl-2 are both essential mediators of innate immunity against fast paralytic killing by Pseudomonas. Furthermore, in agreement with these data, we showed that growing worms in the presence of H2S is sufficient to confer resistance to Pseudomonas fast paralytic killing. Our results suggest the hypoxia-independent hif-1 response in C. elegans evolved to respond to the naturally occurring small molecules H2S and HCN. PMID:21840852

Budde, Mark W; Roth, Mark B

2011-08-11

252

Hydrogen sulfide selectivity with carbonyl sulfide removal to less than PPM levels  

SciTech Connect

Changes in market conditions and plant operating economics require examination of traditional processes and operating practices in gas treating applications for upgrading to more stringent standards of efficiency in order to remain competitive while returning a satisfactory operating profit margin to the company. Anticipated reduction in solvent usage, improvements in Claus sulfur recovery unit performance and lower energy costs induced Ashland's Catlettsburg refinery to convert its entire sulfur removal system from monoethanolamine to methyldiethanolamine. One of the seven product streams being treated required extremely low carbonyl sulfide specifications. When the initial converted operations evidenced a need to improve the carbonyl sulfide removal, GAS/SPEC Tech Service produced an innovative solution which allowed for efficient operation which still achieved these objectives.

Bacon, T.R.; Pearce, R.L.; Foster, W.R. Jr.

1986-01-01

253

Integral equation study of liquid hydrogen fluoride  

Microsoft Academic Search

Liquid hydrogen fluoride is a well-known hydrogen bonded substance, in many aspects related to liquid water, and for which a wide variety of interaction models have recently been proposed. We have studied two of these models by means of a reference hypernetted chain equation in order to assess the ability of this latter approach to describe the properties of this

C. Mart?´n; M. Lombardero; J. A. Anta; E. Lomba

2001-01-01

254

Transport properties of liquid hydrogen fluoride  

Microsoft Academic Search

The dynamical properties of liquid hydrogen fluoride are investigated by a molecular dynamics study of the correlation functions relevant for a generalized hydrodynamics description of transport coefficients. The results are compared with the corresponding ones in liquid water in order to understand the role of hydrogen bonding in the two systems. The different behavior can ultimately be attributed to the

Umberto Balucani; Davide Bertolini; Alessandro Tani; Renzo Vallauri

2000-01-01

255

Hydrogen meter for service in liquid sodium  

Microsoft Academic Search

This standard establishes the requirements for the design, materials, fabrication, quality assurance, examination, and acceptance testing of a hydrogen meter and auxiliary equipment for use in radioactive or nonradioactive liquid sodium service. The meter shall provide a continuous and accurate indication of the hydrogen impurity concentration over the range 0.03 to 10 ppM hydrogen in sodium at temperatures between 800

McCown

1983-01-01

256

The Role of Water for Photodecomposition of Aqueous Hydrogen Sulfide Using Stratified Photocatalyst--Experimental Part  

SciTech Connect

Splitting of hydrogen sulfide using sunlight is a useful reaction to produce hydrogen. Alkaline sulfide solution, which is prepared by dissolving hydrogen sulfide into alkaline water, is selected as the reaction medium of photocatalytic hydrogen generation reaction. In this system, the photocatalytic reaction is assumed to occur as follows: 2H{sub 2}O + 2e{sup -} {yields} H{sub 2} + 2OH{sup -} (1) 2S{sup 2-} + 2h{sup +} {yields} S{sub 2}{sup 2-} (2) However, as the reaction progresses white solids precipitate in the reaction medium. Furthermore, the HPLC analysis suggested that the ratio between the consumption of sulfide ion and the amount of hydrogen generation was about 3:2, which is not stoichiometric. Thus, in this paper, we characterized the white solid precipitate and tried to optimize the solution condition to prevent the precipitation of the same. From our study, the white solid precipitate was confirmed as sulfur derived from the oxidation of the disulfide ion. It was confirmed that the addition of sulfite ions prevented the oxidation of disulfide ions, which causes the precipitation. In the absence of sulfite ions and for sufide ion concentration less than 0.1M, the precipitation of sulfur occurs in a very short reaction time. On the other hand the hydrogen evolution rate retarded when the sulfide ion concentration is higher than 0.1M. This was due to the degradation of the stratified CdS particles. Thus, the optimal concentration of Na2S solution was determined to be around 0.1M.

Arai, Takeo; Shinoda, Kozo; Tohji, Kazuyuki [Graduate School of Environmental Studies, Tohoku University, Aramaki Aza Aoba 20, Aoba-Ku, Sendai 980-8579 (Japan); Matsumoto, Takatoshi [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1, Katahira, Aoba, Sendai 980-8577 (Japan); Sakima, Shuhei [Deptertment of Geoscience and Technology, Tohoku University, Aramaki Aza Aoba 01, Aoba-Ku, Sendai 980-8579 (Japan); Nagashima, Umpei [Grid Technology Research Center, National Institute of Advanced Industrial Science and Technology, 1-1-1 Umezono, Tsukuba 305-8568 (Japan)

2006-05-15

257

49 CFR 179.102-17 - Hydrogen chloride, refrigerated liquid.  

Code of Federal Regulations, 2012 CFR

...false Hydrogen chloride, refrigerated liquid. 179.102-17 Section 179.102-17...102-17 Hydrogen chloride, refrigerated liquid. Each tank car used to transport hydrogen chloride, refrigerated liquid must comply with the following...

2012-10-01

258

49 CFR 179.102-17 - Hydrogen chloride, refrigerated liquid.  

Code of Federal Regulations, 2011 CFR

...false Hydrogen chloride, refrigerated liquid. 179.102-17 Section 179.102-17...102-17 Hydrogen chloride, refrigerated liquid. Each tank car used to transport hydrogen chloride, refrigerated liquid must comply with the following...

2011-10-01

259

Removal of ammonia and hydrogen sulfide using biochar produced from pyrolyzing animal manures  

Technology Transfer Automated Retrieval System (TEKTRAN)

Reducing ammonia and hydrogen sulfide emissions from livestock facilities is an important issue for many communities and livestock producers. The emission of these gases can be substantially reduced using adsorption filters filled with biochar produced from pyrolysis of livestock residuals such as c...

260

Biological treatment process of air loaded with an ammonia and hydrogen sulfide mixture  

Microsoft Academic Search

The physico-chemical characteristics of granulated sludge lead us to develop its use as a packing material in air biofiltration. Then, the aim of this study is to investigate the potential of unit systems packed with this support in terms of ammonia and hydrogen sulfide emissions treatment. Two laboratory scale pilot biofilters were used. A volumetric load of 680 g H2S

Luc Malhautier; Catherine Gracian; Jean-Claude Roux; Jean-Louis Fanlo; Pierre Le Cloirec

2003-01-01

261

Hydrogen sulfide and nonmethane hydrocarbon emissions from broiler houses in the Southeastern United States  

Technology Transfer Automated Retrieval System (TEKTRAN)

Hydrogen sulfide (H2S) and nonmethane hydrocarbon (NMHC) emissions from two mechanically ventilated commercial broiler houses located in the Southeastern United States were continuously monitored over 12 flocks during the one-year period of 2006-2007 as a joint effort between Iowa State University a...

262

On the Adsorption\\/Oxidation of Hydrogen Sulfide on Activated Carbons at Ambient Temperatures  

Microsoft Academic Search

Activated carbons of various origins (bituminous coal, wood, coconut shells, and peat) were studied as adsorbents of hydrogen sulfide. Before the experiments the surface of the adsorbents was characterized by using the sorption of nitrogen, Boehm and potentiometric titrations, thermal analysis, and FTIR. The adsorbents were chosen to differ in their surface areas, pore volumes, and surface acidities. To broaden

Teresa J. Bandosz

2002-01-01

263

An ICT-based fluorescent switch-on probe for hydrogen sulfide in living cells.  

PubMed

An ICT-based fluorescent turn-on probe for hydrogen sulfide with high selectivity has been designed and synthesized. It exhibits up to 62-fold switch-on response toward H2S at given concentrations and can detect H2S in living cells with high sensitivity. PMID:23949387

Li, Xin; Zhang, Shuai; Cao, Ji; Xie, Nan; Liu, Tao; Yang, Bo; He, Qiaojun; Hu, Yongzhou

2013-10-01

264

The regulatory effect of hydrogen sulfide on hypoxic pulmonary hypertension in rats  

Microsoft Academic Search

Hypoxic pulmonary hypertension (HPH) is an important pathophysiological process. The mechanism of HPH is still not fully understood. Recent studies showed that hydrogen sulfide (H2S) could relax vascular smooth muscles and inhibit the proliferation of cultured vascular smooth muscle cells. Our study showed that both the gene expression of cystathionine ?-lyase (CSE), one of the H2S generating enzymes, and the

Zhang Chunyu; Du Junbao; Bu Dingfang; Yan Hui; Tang Xiuying; Tang Chaoshu

2003-01-01

265

Occupational fatality and persistent neurological sequelae after mass exposure to hydrogen sulfide  

Microsoft Academic Search

Exposure to hydrogen sulfide (H2S) has been associated with death as well as survival following coma with or without hypoxic brain damage. The release of H2S at a beachfront construction site led to the emergency evaluation and treatment of 37 people, with six admissions and one death. At least one victim, who underwent extensive therapy with hyperbaric oxygen, developed persistent

Jack W Snyder; Ellen F Safir; Gregg P Summerville; Robert A Middleberg

1995-01-01

266

Hydrogen sulfide is a reversible inhibitor of the NADH oxidase activity of synaptic plasma membranes  

Microsoft Academic Search

Hydrogen sulfide is now accepted as a neuromodulator, which can be involved in neuronal defence against oxidative stress insults in the brain. In this work we show that concentrations of H2S within the physiological range reported in the brain produce a reversible inhibition of the NADH oxidase activity and coupled superoxide anion production by synaptic plasma membranes from rat brain.

Alejandro K. Samhan-Arias; Miguel A. Garcia-Bereguiain; Carlos Gutierrez-Merino

2009-01-01

267

Hydrogen Sulfide, a Toxic Gas with Cardiovascular Properties in Uremia: How Harmful Is It?  

Microsoft Academic Search

Hydrogen sulfide (H2S) is a poisonous gas which can be lethal. However, it is also produced endogenously, thus belonging to the family of gasotransmitters along with nitric oxide and carbon monoxide. H2S is in fact involved in mediating several signaling and cytoprotective functions, for example in the nervous, cardiovascular, and gastrointestinal systems, such as neuronal transmission, blood pressure regulation and

Alessandra F. Perna; Diana Lanza; Immacolata Sepe; Ilaria Raiola; Rosanna Capasso; Natale G. De Santo; Diego Ingrosso

2011-01-01

268

Hydrogen sulfide acts as a regulator of flower senescence in plants  

Microsoft Academic Search

We report the effects of hydrogen sulfide (H2S) on flower senescence in various species of cut flowers. H2S was found to delay flower opening and senescence in cut flowers and branches from Erigeron annuus (L.), Euonymus maackii Rupr., Hibiscus syriacus L., Liriope spicata (Thump.), Loropetalum chinense (R. Br.), Punica granatum L., Rosa chinensis Jacq., and Salix matsudana Koidz. Cut explants

Hua Zhang; Shu-Li Hu; Ze-Jun Zhang; Lan-Ying Hu; Cheng-Xi Jiang; Zhao-Jun Wei; Jian Liu; Hui-Li Wang; Shao-Tong Jiang

2011-01-01

269

Hydrogen sulfide: from the smell of the past to the mediator of the future?  

Microsoft Academic Search

Gases such as nitric oxide and carbon monoxide play important roles both in normal physiology and in disease. In recent years, interest has been directed towards other naturally occurring gases, notably hydrogen sulfide (H2S), which is both a potent vasodilator and a mediator of long-term potentiation in the brain. This article focuses on recent work that suggests a role for

Philip K Moore; Madhav Bhatia; Shabbir Moochhala

2003-01-01

270

Removal of hydrogen sulfide from hot fuel gas using an electrochemical membrane system  

Microsoft Academic Search

Sulfur is a natural contaminant in nearly all fossil fuel supplies. When a fuel stream is gasified or reformed, the sulfur manifests itself in the form of hydrogen sulfide, H2S. Extraordinary effort is put forth to remove H2S to at least ppm levels before the fuel can be used for power generation. To compete with current methods, an electrochemical membrane

Adrian Alan Burke

2003-01-01

271

Control of hydrogen sulfide emission from geothermal power plants. Volume I. Summary of results. Final report  

Microsoft Academic Search

A program of laboratory and pilot plant tests, detailed process and project engineering work, and process engineering and economic evaluation studies has been carried out in support of the design of a test facility for demonstration of the copper sulfate process for the removal of hydrogen sulfide from geothermal steam at turbine upstream conditions. A demonstration plant has been designed

F. C. Brown; W. W. Harvey; R. B. Warren

1979-01-01

272

Hazardous Peak Concentrations of Hydrogen Sulfide Gas Related to the Sewage Purification Process  

Microsoft Academic Search

The concentration of hydrogen sulfide in the atmosphere of a sewage purification plant in Norway was studied. Continuous measurements over several 3-week periods showed that the concentrations generally were lower than 2 ppm, but peak concentrations over 100 ppm were discovered. Rapid onset and decline characterized these peak concentrations, which occurred at regular intervals. Through evaluation of the time pattern

Per Søstrand; Bjørn Tvedt; Wijnand Eduard; Erik Bye; Kari Heldal

2000-01-01

273

Bench-to-bedside review: Hydrogen sulfide – the third gaseous transmitter: applications for critical care  

Microsoft Academic Search

ABSTRACT: Hydrogen sulfide (H2S), a gas with the characteristic odor of rotten eggs, is known for its toxicity and as an environmental hazard, inhibition of mitochondrial respiration resulting from blockade of cytochrome c oxidase being the main toxic mechanism. Recently, however, H2S has been recognized as a signaling molecule of the cardiovascular, inflammatory and nervous systems, and therefore, alongside nitric

Florian Wagner; Pierre Asfar; Enrico Calzia; Peter Radermacher; Csaba Szabó

2009-01-01

274

Measurement, analysis, and modeling of hydrogen sulfide emissions from a swine facility in North Carolina  

Microsoft Academic Search

Annual global source contributions of sulfur compounds to the natural atmospheric environment are estimated to be 142 x 106 tons. Although not quantified, volatilization from animal wastes may be an important source of gaseous reduced sulfur compounds. Hydrogen sulfide (H2S) is a colorless gas emitted during decomposition of hog manure that produces an offensive \\

Jessica Blunden

2006-01-01

275

Selective turn-on fluorescent probes for imaging hydrogen sulfide in living cells†  

PubMed Central

Hydrogen sulfide (H2S) is an important biological messenger but few biologically-compatible methods are available for its detection. Here we report two bright fluorescent probes that are selective for H2S over cysteine, glutathione and other reactive sulfur, nitrogen, and oxygen species. Both probes are demonstrated to detect H2S in live cells.

Montoya, Leticia A.; Pluth, Michael D.

2012-01-01

276

CHROMATOGRAPHIC SEPARATION AND IDENTIFICATION OF PRODUCTS FROM THE REACTION OF DIMETHYLARSINIC ACID WITH HYDROGEN SULFIDE  

EPA Science Inventory

The reaction of dimethylarsinic acid (DMAV) with hydrogen sulfide (H2S) is of biological significance and may be implicated in the overall toxicity and carcinogenicity of arsenic. The course of the reaction in aqueous phase was monitored and an initial product, dimethylthioarsin...

277

Evolution of hydrogen sulfide in sour saline aquifers during carbon dioxide sequestration  

Microsoft Academic Search

Many deep saline aquifers suitable for carbon dioxide (CO2) sequestration contain measurable concentrations of hydrogen sulfide (H2S). These aquifers are described here as sour saline aquifers and the other ones as ordinary saline aquifers. Sour saline aquifers occur wherever even minor amounts of anhydrite or other sulfate sources are present in the formation. In this paper, compositional modeling of CO2

Seyyed M. Ghaderi; David W. Keith; Rob Lavoie; Yuri Leonenko

2011-01-01

278

Removal of hydrogen sulfide and carbon dioxide from injection water by a hydrocarbon gas cycling process  

Microsoft Academic Search

Equipment handling water containing relatively large quantities of carbon dioxide and hydrogen sulfide is susceptible to excessive corrosion that may attain conditions not economically controllable using corrosion inhibitors. One such extreme condition developed in a waterflood, where selective injection into multiple zones through common well bores necessitated annular injection that eliminated the feasibility of using downhole protective coatings. Severe tubing

1968-01-01

279

Effect of Low Concentrations of Carbon Disulfide and Hydrogen Sulfide on Intrauterine Development in Rats.  

National Technical Information Service (NTIS)

Male and female rats were exposed to low concentrations of carbon disulfide and hydrogen sulfide for 70 to 90 days and then were mated. In a second series, females only were exposed and in a third series, males only were exposed. On the 20th day of pregna...

I. R. Barilyak I. A. Vasil'eva L. P. Kalinovskaya

1975-01-01

280

Reaction of hydrogen sulfide with oxygen in the presence of sulfite  

SciTech Connect

Commonly, abatement of hydrogen sulfide emission from a geothermal powerplant requires that hydrogen sulfide dissolved in the cooling water be eliminated by chemical reaction. Oxidation by atmospheric oxygen is the preferred reaction, but requires a suitable catalyst. Nickel is the most potent and thereby cheapest catalyst for this purpose. One mg/L nickel in the cooling water would allow 99% removal of hydrogen sulfide to be attained. A major drawback of catalytic air oxidation is that colloidal sulfur is a major reaction product; this causes rapid sludge accumulation and deposition of sulfur scale. We studied the kinetics and product distribution of the reaction of hydrogen sulfide with oxygen, catalyzed by nickel. Adding sodium sulfite to the solution completely suppresses formation of colloidal sulfur by converting it to thiosulfate. The oxidation reaction is an autocatalytic, free radical chain reaction. A rate expression for this reaction and a detailed reaction mechanism were developed. Nickel catalyzes the chain initiation step, and polysulfidoradical ions propagate the chains. Several complexes of iron and cobalt were also studied. Iron citrate and iron N-hydroxyEDTA are the most effective iron based catalysts. Uncomplexed cobalt is as effective as nickel, but forms a precipitate of cobalt oxysulfide and is too expensive for practical use. 33 figures, 9 tables.

Weres, O.; Tsao, L.

1983-01-14

281

Reaction of Hydrogen Sulfide with Oxygen in the Presence ofSulfite  

SciTech Connect

Commonly, abatement of hydrogen sulfide emissions from a geothermal powerplant requires that hydrogen sulfide dissolved in the cooling water be eliminated by chemical reaction. Oxidation by atmospheric oxygen is the preferred reaction, but requires a suitable catalyst. Nickel is the most potent and thereby cheapest catalyst for this purpose. One Mg/L nickel in the cooling water would allow 99% removal of hydrogen sulfide to be attained. A major drawback of catalytic air oxidation is that colloidal sulfur is a major reaction product; this causes rapid sludge accumulation and deposition of sulfur scale. The authors studied the kinetics and product distribution of the reaction of hydrogen sulfide with oxygen, catalyzed by nickel. Adding sodium sulfite to the solution completely suppresses formation of colloidal sulfur by converting it to thiosulfate. The oxidation reaction is an autocatalytic, free radical chain reaction. A rate expression for this reaction and a detailed reaction mechanism were developed. Nickel catalyzes the chain initiation step, and polysulfidoradical ions propagate the chains. Several complexes of iron and cobalt were also studied. Iron citrate and iron N-hydroxyEDT are the most effective iron based catalysts. Uncomplexed cobalt is as effective as nickel, but forms a precipitate of cobalt oxysulfide and is too expensive for practical use.

Weres, Oleh; Tsao, Leon

1983-01-01

282

Hydrogen sulfide removal from retort off-gases using oil shale  

Microsoft Academic Search

Occidental Petroleum Corp. has developed a modified in situ retorting process for producing synthetic petroleum from oil shale. Large volumes of hydrocarbon containing gas are byproducts of the oil production. Hydrogen sulfide, a pollutant, is contained in the gas, and its presence is a characteristic common to both in situ, and aboveground retorting methods. A new HâS removal technique which

L. E. Compton; W. H. Rowan

1977-01-01

283

IRIS TOXICOLOGICAL REVIEW AND SUMMARY DOCUMENTS FOR HYDROGEN SULFIDE (EXTERNAL REVIEW DRAFT)  

EPA Science Inventory

Hydrogen sulfide (H2S) is a colorless gas with a strong odor of rotten eggs. Its primary uses include the production of elemental sulfur and sulfuric acid, the manufacture of heavy water and other chemicals. Occupational exposure occurs primarily from its presence in petroleum, n...

284

76 FR 64022 - Hydrogen Sulfide; Community Right-to-Know Toxic Chemical Release Reporting  

Federal Register 2010, 2011, 2012, 2013

...Hydrogen Sulfide; Community Right-to-Know Toxic Chemical Release Reporting AGENCY: Environmental...Right-to-Know Act (EPCRA) section 313 toxic chemical release reporting requirements...added to the EPCRA section 313 list of toxic chemicals in a final rule published...

2011-10-17

285

A novel and cost-effective hydrogen sulfide removal technology using tire derived rubber particles  

Microsoft Academic Search

Hydrogen sulfide (H2S) is corrosive, toxic, and produced during the anaerobic digestion process at wastewater treatment plants. Tire derived rubber particles (TDRPTM) and other rubber material (ORMTM) are recycled waste rubber products distributed by Envirotech Systems, Inc (Lawton, IA). They were found to be effective at removing H2S from biogas in a previous study. A scrubber system utilizing TDRPTM and

Andrea Mary Siefers

2010-01-01

286

Exogenous hydrogen sulfide induces functional inhibition and cell death of cytotoxic lymphocytes subsets.  

PubMed

The toxic effects of exogenous hydrogen sulfide on peripheral blood lymphocytes have been investigated in detail. Hydrogen sulfide is now considered as a gasotransmitter with specific functional roles in different cell types, like neurons and vascular smooth muscle. Here we show that exogenous hydrogen sulfide induces a caspase-independent cell death of peripheral blood lymphocytes that depends on their intracellular glutathione levels, with a physiologically relevant subset specificity for CD8+ T cells and NK cells. Although lymphocyte activation does not modify their sensitivity to HS-, after 24 h exposure to hydrogen sulfide surviving lymphocyte subsets show a dramatically decreased proliferation in response to mitogens and a reduced IL-2 production. Overall, our data demonstrate that HS- reduces the cellular cytotoxic response of peripheral blood lymphocytes as well as their production of IL-2, therefore de-activating the major players of local inflammatory responses, adding new basic knowledge to the clinically well known anti-inflammatory effects of sulfur compounds. PMID:17516567

Mirandola, Prisco; Gobbi, Giuliana; Sponzilli, Ivonne; Pambianco, Maurizia; Malinverno, Chiara; Cacchioli, Antonio; De Panfilis, Giuseppe; Vitale, Marco

2007-12-01

287

Hydrogen sulfide protects astrocytes against H 2O 2-induced neural injury via enhancing glutamate uptake  

Microsoft Academic Search

Excess extracellular glutamate, the main excitatory neurotransmitter, may result in excitotoxicity and neural injury. The present study was designed to study the effect of hydrogen sulfide (H2S), a novel neuromodulator, on hydrogen peroxide (H2O2) -induced glutamate uptake impairment and cellular injuries in primary cultured rat cortical astrocytes. We found that NaHS (an H2S donor, 0.1-1000 ?M) reversed H2O2-induced cellular injury in

Ming Lu; Li-Fang Hu; Gang Hu; Jin-Song Bian

2008-01-01

288

Electrochemical polishing of hydrogen sulfide from coal synthesis gas  

Microsoft Academic Search

An advanced process has been developed for the separation of HâS from coal gasification product streams through an electrochemical membrane. This technology is developed for use in coal gasification facilities providing fuel for cogeneration coal fired electrical power facilities and Molten Carbonate Fuel Cell electrical power facilities. HâS is removed from the syn-gas by reduction to the sulfide ion and

E. F. Gleason; J. Winnick

1995-01-01

289

Electrochemical polishing of hydrogen sulfide from coal synthesis gas  

Microsoft Academic Search

An advanced process has been developed for the separation of H2S from coal gasification product streams through an electrochemical membrane. This technology is developed for use in coal gasification facilities providing fuel for cogeneration coal fired electrical power facilities and molten carbonate fuel cell (MCFC) electrical power facilities. H2S is removed from the syn-gas by reduction to the sulfide ion

S. R. Alexander; J. Winnick

1994-01-01

290

Plasma-chemical treatment of hydrogen sulfide in natural gas processing. Final report, May 1991December 1992  

Microsoft Academic Search

A new process for the treatment of hydrogen sulfide waste that uses microwave plasma-chemical technology has been under development in Russia and the United States. Whereas the present waste-treatment technology, at best, only recovers sulfur, this novel process recovers both hydrogen and sulfur by dissociating hydrogen sulfide in a plasma by means of a microwave or radio-frequency reactor. A research

J. B. L. Harkness; R. D

1993-01-01

291

Use of AERMOD to determine a hydrogen sulfide emission factor for swine operations by inverse modeling  

NASA Astrophysics Data System (ADS)

This study was conducted to determine both optimal settings applied to the plume dispersion model, AERMOD, and a scalable emission factor for accurately determining the spatial distribution of hydrogen sulfide concentrations in the vicinity of swine concentrated animal feeding operations (CAFOs). These operations emit hydrogen sulfide from both housing structures and waste lagoons. With ambient measurements made at 4 stations within 1 km of large swine CAFOs in Iowa, an inverse-modeling approach applied to AERMOD was used to determine hydrogen sulfide emission rates. CAFO buildings were treated as volume sources whereas nearby lagoons were modeled as area sources. The robust highest concentration (RHC), calculated for both measured and modeled concentrations, was used as the metric for adjusting the emission rate until the ratio of the two RHC levels was unity. Utilizing this approach, an average emission flux rate of 0.57 ?g m -2 s -1 was determined for swine CAFO lagoons. Using the average total animal weight (kg) of each CAFO, an average emission factor of 6.06 × 10 -7 ?g yr -1 m -2 kg -1 was calculated. From studies that measured either building or lagoon emission flux rates, building fluxes, on a floor area basis, were considered equal to lagoon flux rates. The emission factor was applied to all CAFOs surrounding the original 4 sites and surrounding an additional 6 sites in Iowa, producing an average modeled-to-measured RHC ratio of 1.24. When the emission factor was applied to AERMOD to simulate the spatial distribution of hydrogen sulfide around a hypothetical large swine CAFO (1 M kg), concentrations within 0.5 km from the CAFO exceeded 25 ppb and dropped to 2 ppb within 6 km of the CAFO. These values compare to a level of 30 ppb that has been determined by the State of Iowa as a threshold level for ambient hydrogen sulfide levels.

O'Shaughnessy, Patrick T.; Altmaier, Ralph

2011-09-01

292

Use of AERMOD to Determine a Hydrogen Sulfide Emission Factor for Swine Operations by Inverse Modeling  

PubMed Central

This study was conducted to determine both optimal settings applied to the plume dispersion model, AERMOD, and a scalable emission factor for accurately determining the spatial distribution of hydrogen sulfide concentrations in the vicinity of swine concentrated animal feeding operations (CAFOs). These operations emit hydrogen sulfide from both housing structures and waste lagoons. With ambient measurements made at 4 stations within 1 km of large swine CAFOs in Iowa, an inverse-modeling approach applied to AERMOD was used to determine hydrogen sulfide emission rates. CAFO buildings were treated as volume sources whereas nearby lagoons were modeled as area sources. The robust highest concentration (RHC), calculated for both measured and modeled concentrations, was used as the metric for adjusting the emission rate until the ratio of the two RHC levels was unity. Utilizing this approach, an average emission flux rate of 0.57 µg/m2-s was determined for swine CAFO lagoons. Using the average total animal weight (kg) of each CAFO, an average emission factor of 6.06 × 10?7 µg/yr-m2-kg was calculated. From studies that measured either building or lagoon emission flux rates, building fluxes, on a floor area basis, were considered equal to lagoon flux rates. The emission factor was applied to all CAFOs surrounding the original 4 sites and surrounding an additional 6 sites in Iowa, producing an average modeled-to-measured RHC ratio of 1.24. When the emission factor was applied to AERMOD to simulate the spatial distribution of hydrogen sulfide around a hypothetical large swine CAFO (1M kg), concentrations 0.5 km from the CAFO were 35 ppb and dropped to 2 ppb within 6 km of the CAFO. These values compare to a level of 30 ppb that has been determined by the State of Iowa as a threshold level for ambient hydrogen sulfide levels.

O'Shaughnessy, Patrick T.; Altmaier, Ralph

2011-01-01

293

Automated detection of hydrogen sulfide release from thiosulfate by Salmonella spp.  

PubMed

Hydrogen sulfide production is used in conventional tests for identification and differentiation of Salmonella spp. from other species of Enterobacteriaceae, and a black precipitate on agar media is the indicator of the reaction. Selective liquid media were formulated for automated optical detection of H2S in salmonellae using the BioSys instrument. The media contained thiosulfate and ferric ammonium citrate, and production of H2S caused copious black pigmentation of the broth. Combination of the H2S indicators with dulcitol or xylose as fermentable carbohydrate, lysine, ornithine or arginine to induce decarboxylase activity, and Tergitol 4 as inhibitor selectively identified six Salmonella spp. by a sharp drop in transmittance at 585 nm. The time for detection of transmittance changes was inversely proportional to initial numbers of CFU in the media: 10 h for 10(5) CFU/ml and 17 h for 10(1) CFU/ml. No detection was observed in six non-Salmonella species of Enterobacteriaceae tested. PMID:9709237

Shelef, L A; Tan, W

1998-05-01

294

Cytochrome Oxidase Inhibition Induced by Acute Hydrogen Sulfide Inhalation: Correlation with Tissue Sulfide Concentrations in the Rat Brain, Liver, Lung, and Nasal Epithelium  

Microsoft Academic Search

Hydrogen sulfide (H2S) is an important brain, lung, and nose toxicant. Inhibition of cytochrome oxidase is the primary biochem- ical effect associated with lethal H2S exposure. The objective of this study was to evaluate the relationship between the concentra- tion of sulfide and cytochrome oxidase activity in target tissues following acute exposure to sublethal concentrations of inhaled H2S. Hindbrain, lung,

David C. Dorman; Brian E. McManus; Kristen C. Mahle; R. Arden James; Melanie F. Struve

2002-01-01

295

GC–MS Analysis of Hydrogen Sulfide, Carbonyl Sulfide, Methanethiol, Carbon Disulfide, Methyl Thiocyanate and Methyl Disulfide in Mainstream Vapor Phase Cigarette Smoke  

Microsoft Academic Search

A method is described for the simultaneous analysis of hydrogen sulfide, carbonyl sulfide, methanethiol, carbon disulfide,\\u000a methyl thiocyanate and methyl disulfide in mainstream vapor phase (MVP) cigarette smoke by gas chromatography–mass spectrometry.\\u000a The fresh MVP smoke was collected in a gas bag, followed by injection of a 50 ?L gas sample into the GC inlet via an automatic\\u000a six-port valve. The

Ji-Zhou Dong; Samuel M. DeBusk

2010-01-01

296

Hydrogen sulfide adsorption on MOFs and MOF/graphite oxide composites.  

PubMed

Composites of a copper-based metal-organic framework (MOF) and graphite oxide (GO) were tested for hydrogen sulfide removal at ambient conditions. In order to understand the mechanisms of adsorption, the initial and exhausted samples were analyzed by various techniques including X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric analyses, and sorption of nitrogen. Compared to the parent materials, an enhancement in hydrogen sulfide adsorption was found. It was the result of physical adsorption of water and H(2)S in the pore space formed at the interface between the MOF units and the graphene layers where the dispersive forces are the strongest. Besides physisorption, reactive adsorption was found as the main mechanism of retention. H(2)S molecules bind to the copper centers of the MOF. They progressively react with the MOF units resulting in the formation of copper sulfide. This leads to the collapse of the MOF structure. Water enhances adsorption in the composites as it allows the dissolution of hydrogen sulfide. PMID:20945452

Petit, Camille; Mendoza, Barbara; Bandosz, Teresa J

2010-12-01

297

Control of hydrogen sulfide production in oil fields by managing microbial communities through nitrate or nitrite addition  

Microsoft Academic Search

Nitrate or nitrite injection into oil reservoirs during water flooding has the potential to control biological souring, the production of hydrogen sulfide (H2S) by sulfate-reducing bacteria (SRB). Souring control is essential because sulfide is toxic, sulfide precipitates can plug reservoir formations, souring lowers crude oil value, and SRB induce corrosion. Nitrate and nitrite can stimulate heterotrophic nitrate- or nitrite-reducing bacteria

Casey R. J. Hubert

2004-01-01

298

Method of removing hydrogen sulfide from gases utilizing a zinc oxide sorbent and regenerating the sorbent  

DOEpatents

A spent solid sorbent resulting from the removal of hydrogen sulfide from a fuel gas flow is regenerated with a steam-air mixture. The mixture of steam and air may also include additional nitrogen or carbon dioxide. The gas mixture contacts the spent sorbent containing metal sulfide at a temperature above 500.degree. C. to regenerate the sulfide to metal oxide or carbonate. Various metal species including the period four transition metals and the lanthanides are suitable sorbents that may be regenerated by this method. In addition, the introduction of carbon dioxide gas permits carbonates such as those of strontium, barium and calcium to be regenerated. The steam permits regeneration of spent sorbent without formation of metal sulfate. Moreover, the regeneration will proceed with low oxygen concentrations and will occur without the increase in temperature to minimize the risk of sintering and densification of the sorbent.

Jalan, Vinod M. (Concord, MA); Frost, David G. (Maynard, MA)

1984-01-01

299

Hydrogen Sulfide Protects HUVECs against Hydrogen Peroxide Induced Mitochondrial Dysfunction and Oxidative Stress  

PubMed Central

Background Hydrogen sulfide (H2S) has been shown to have cytoprotective effects in models of hypertension, ischemia/reperfusion and Alzheimer's disease. However, little is known about its effects or mechanisms of action in atherosclerosis. Therefore, in the current study we evaluated the pharmacological effects of H2S on antioxidant defenses and mitochondria protection against hydrogen peroxide (H2O2) induced endothelial cells damage. Methodology and Principal Findings H2S, at non-cytotoxic levels, exerts a concentration dependent protective effect in human umbilical vein endothelial cells (HUVECs) exposed to H2O2. Analysis of ATP synthesis, mitochondrial membrane potential (??m) and cytochrome c release from mitochondria indicated that mitochondrial function was preserved by pretreatment with H2S. In contrast, in H2O2 exposed endothelial cells mitochondria appeared swollen or ruptured. In additional experiments, H2S was also found to preserve the activities and protein expressions levels of the antioxidants enzymes, superoxide dismutase, catalase, glutathione peroxidase and glutathione-S-transferase in H2O2 exposed cells. ROS and lipid peroxidation, as assessed by measuring H2DCFDA, dihydroethidium (DHE), diphenyl-l-pyrenylphosphine (DPPP) and malonaldehyde (MDA) levels, were also inhibited by H2S treatment. Interestingly, in the current model, D, L-propargylglycine (PAG), a selective inhibitor of cystathionine ?-lyase (CSE), abolished the protective effects of H2S donors. Innovation This study is the first to show that H2S can inhibit H2O2 mediated mitochondrial dysfunction in human endothelial cells by preserving antioxidant defences. Significance H2S may protect against atherosclerosis by preventing H2O2 induced injury to endothelial cells. These effects appear to be mediated via the preservation of mitochondrial function and by reducing the deleterious effects of oxidative stress.

Wen, Ya-Dan; Wang, Hong; Kho, Sok-Hong; Rinkiko, Suguro; Sheng, Xiong; Shen, Han-Ming; Zhu, Yi-Zhun

2013-01-01

300

Theoretical hugoniot of liquid hydrogen fluoride.  

National Technical Information Service (NTIS)

A new temperature-dependent exponential-six potential for HF is presented for high-temperature applications. We use it to examine effects of hydrogen bonding in liquid HF under shock conditions. 9 refs., 3 figs.

F. H. Ree D. F. Calef

1989-01-01

301

Theoretical hugoniot of liquid hydrogen fluoride  

SciTech Connect

A new temperature-dependent exponential-six potential for HF is presented for high-temperature applications. We use it to examine effects of hydrogen bonding in liquid HF under shock conditions. 9 refs., 3 figs.

Ree, F.H.; Calef, D.F.

1989-07-01

302

Pair Correlation Functions in Liquid Metallic Hydrogen  

Microsoft Academic Search

The quantal hypernetted chain (QHNC) equation, derived from the Kohn-Sham-Mermin theory, is solved for the pair correlation functions in a liquid metallic hydrogen (LMH) modelled as a proton-electron mixture in the range where protons constitute a classical liquid and electrons are in a degenerate state. In the sufficiently high temperature and high density region, hydrogen atoms are found to form

Junzo Chihara

1984-01-01

303

Velocity correlations in liquid hydrogen fluoride  

Microsoft Academic Search

The center-of-mass velocity autocorrelation function is analyzed by computer simulation in a model of liquid hydrogen fluoride at two state points. In comparison with water (another hydrogen-bonded liquid) new features arise. To understand the peculiarities of HF, we have investigated atomic velocity correlations in both the laboratory and a molecular frame. The comparison of the frequency spectra permits to ascertain

U. Balucani; D. Bertolini; G. Sutmann; A. Tani; R. Vallauri

1999-01-01

304

Mechanistic study of microbial control of hydrogen sulfide production in oil reservoirs.  

PubMed

Microbial control of biogenic production of hydrogen sulfide in oil fields was studied in a model system consisting of pure cultures of the nitrate-reducing, sulfide-oxidizing bacterium (NR-SOB) Thiomicrospira sp. strain CVO and the sulfate-reducing bacterium (SRB) Desulfovibrio sp. strain Lac6, as well as in microbial cultures enriched from produced water of a Canadian oil reservoir. The presence of nitrate at concentrations up to 20 mM had little effect on the rate of sulfate reduction by a pure culture of Lac6. Addition of CVO imposed a strong inhibition effect on production of sulfide. In the absence of added nitrate SRB we were able to overcome this effect after an extended lag phase. Simultaneous addition of CVO and nitrate stopped the production of H2S immediately. The concentration of sulfide decreased to a negligible level due to nitrate-dependent sulfide oxidation activity of CVO. This was not prevented by raising the concentration of Na-lactate, the electron donor for sulfate reduction. Similar results were obtained with enrichment cultures. Enrichments of produced water with sulfide and nitrate were dominated by CVO, whereas enrichments with sulfate and Na-lactate were dominated by SRB. Addition of an NR-SOB enrichment to an SRB enrichment inhibited the production of sulfide. Subsequent addition of sufficient nitrate caused the sulfide concentration to drop to zero. A similar response was seen in the presence of nitrate alone, although after a pronounced lag time, it was needed for emergence of a sizable CVO population. The results of the present study show that two mechanisms are involved in microbial control of biogenic sulfide production. First, addition of NR-SOB imposes an inhibition effect, possibly by increasing the environmental redox potential to levels which are inhibitory for SRB. Second, in the presence of sufficient nitrate, NR-SOB oxidize sulfide, leading to its complete removal from the environment. Successful microbial control of H2S in an oil reservoir is crucially dependent on the simultaneous presence of NR-SOB (either indigenous population or injected) and nitrate in the environment. PMID:11427944

Nemati, M; Jenneman, G E; Voordouw, G

2001-09-01

305

Atmospheric hydrogen sulfide over the equatorial Pacific (SAGA 3)  

SciTech Connect

Atmospheric H{sub 2}S concentrations were measured over the equatorial Pacific on leg 1 of the third Soviet-American Gases and Aerosols (SAGA 3) cruise during February and March 1990. Five N-S transects were made across the equator between Hawaii and American Samoa. The concentrations ranged from below the detection limit of 0.4 {+-} 0.5 (1{sigma}) to 14.4 ppt with an average value of 3.6 {+-} 2.3 ppt (1{sigma}, n = 72). The highest concentrations were found on the easternmost two transects just south of the equator. The average concentration of 3.6 ppt observed on this cruise is the lowest reported value for background atmospheric H{sub 2}S over the tropical oceans. A lack of correlation between {sup 222}Rn and H{sub 2}S in this region is in the range of 9 to 21 x 10{sup {minus}8} mol m{sup {minus}2} d{sup {minus}1}. From this flux the concentration of free sulfide (H{sub 2}S + S{sup 2{minus}}) in the surface mixed layer of the ocean is estimated to be in the range of 32 to 67 pmol L{sup {minus}1}. In the atmospheric the oxidation of H{sub 2}S produces SO{sub 2} at a rate of 2.1 to 4.4 x 10{sup {minus}11} mol m{sup {minus}3} d{sup {minus}1} which is only a small fraction of that estimated from the oxidation of dimethyl sulfide (DMS) in this region. A diurnal cycle was not observed in the H{sub 2}S data recorded during this cruise. 26 refs., 4 figs., 2 tabs.

Yvon, S.A.; Cooper, D.J.; Saltzman, E.S. [Univ. of Miami, FL (United States); Koropalov, V. [Univ. of Miami, FL (United States)]|[Institute of Applied Geophysics, Moscow (Russian Federation)

1993-09-20

306

Elevated corrosion rates and hydrogen sulfide in homes with 'Chinese Drywall'.  

PubMed

In December 2008, the U.S. Consumer Product Safety Commission (CPSC) began receiving reports about odors, corrosion, and health concerns related to drywall originating from China. In response, a detailed environmental health and engineering evaluation was conducted of 41 complaint and 10 non-complaint homes in the Southeast U.S. Each home investigation included characterization of: 1) drywall composition; 2) indoor and outdoor air quality; 3) temperature, moisture, and building ventilation; and 4) copper and silver corrosion rates. Complaint homes had significantly higher hydrogen sulfide concentrations (mean 0.82 vs. sulfide and silver sulfide corrosion compared to non-complaint homes (Cu(2)S: 476 vs. <32 Å/30 d, p<0.01; Ag(2)S: 1472 vs. 389 Å/30 d, p<0.01). The abundance of carbonate and strontium in drywall was also elevated in complaint homes, and appears to be useful objective marker of problematic drywall in homes that meet other screening criteria (e.g., constructed or renovated in 2006-2007, reports of malodor and accelerated corrosion). This research provides empirical evidence of the direct association between homes constructed with 'Chinese Drywall' in 2006-2007 and elevated corrosion rates and hydrogen sulfide concentrations in indoor air. PMID:22525559

Allen, Joseph G; MacIntosh, David L; Saltzman, Lori E; Baker, Brian J; Matheson, Joanna M; Recht, Joel R; Minegishi, Taeko; Fragala, Matt A; Myatt, Theodore A; Spengler, John D; Stewart, James H; McCarthy, John F

2012-04-21

307

40 CFR 60.648 - Optional procedure for measuring hydrogen sulfide in acid gas-Tutwiler Procedure. 1  

Code of Federal Regulations, 2013 CFR

...measuring hydrogen sulfide in acid gasâTutwiler Procedure. 1 1 Gas Engineers Handbook, Fuel Gas Engineering Practices, The Industrial Press, 93 Worth Street, New York, NY, 1966, First Edition, Second Printing, page 6/25...

2013-07-01

308

Hydrogen Sulfide as a Driver of Selectivity in Marine Invertebrate Extinctions During the Permian-Triassic Event  

NASA Astrophysics Data System (ADS)

Hydrogen sulfide is not only a potential mass extinction kill mechanism but also a selective agent by which some organisms are preferentially removed. We present investigations into the sensitivity of key marine invertebrate groups.

Ballanti, L. A.; Roth, M. B.; Ward, P. D.

2010-04-01

309

75 FR 19319 - Hydrogen Sulfide; Community Right-to-Know Toxic Chemical Release Reporting; Extension of Comment...  

Federal Register 2010, 2011, 2012, 2013

...Hydrogen Sulfide; Community Right-to-Know Toxic Chemical Release Reporting; Extension...Right-to- Know Act (EPCRA) section 313 toxic chemical release reporting requirements...Reporting and recordkeeping requirements, and Toxic chemicals. Dated: April 7, 2010....

2010-04-14

310

Hydrogen production from hydrogen sulfide using membrane reactor integrated with porous membrane having thermal and corrosion resistance  

Microsoft Academic Search

Using mathematical model and experimental method, the thermal decomposition of hydrogen sulfide in membrane reactor with porous membrane which has Knudsen diffusion characteristics was investigated. With mathematical model, the effect of characteristics of membrane reactor and operating conditions on H2 concentration in the permeate chamber, yH2, which increases at higher reaction temperature, lower pressure and higher ratio of cross-sectional area

Hirofumi Ohashi; Haruhiko Ohya; Masahiko Aihara; Youichi Negishi; Svetlana I. Semenova

1998-01-01

311

Protection of steel by inhibitors from corrosion, hydrogen absorption, and corrosion-mechanical failure in a hydrogen sulfide medium  

Microsoft Academic Search

The effectiveness of the inhibitors in retarding corrosion, hydrogen impregnation, and corrosion-mechanical failure of steelwas determined in a 3% NaCI solution saturated with hy- drogen sulfide at atmospheric pressure and a temperature of 30~ The concentration of~the additions was 1.5 g\\/liter (selected for a comparative characteristic of the protective effec- tiveness of the inhibitors, the maximum of which appears at

E. I. Svist; V. M. Zhovnirchuk; A. K. Mindyuk; Yu. I. Babei

1983-01-01

312

Dechlorination of Chloropicrin and 1,3-Dichloropropene by Hydrogen Sulfide Species:  Redox and Nucleophilic Substitution Reactions  

Microsoft Academic Search

The chlorinated fumigants chloropicrin (trichloronitromethane) and 1,3-dichloropropene (1,3-D) are extensively used in agricultural production for the control of soilborne pests. The reaction of these two fumigants with hydrogen sulfide species (H2S and HS-) was examined in well-defined anoxic aqueous solutions. Chloropicrin underwent an extremely rapid redox reaction in the hydrogen sulfide solution. Transformation products indicated reductive dechlorination of chloropicrin by

Wei Zheng; Scott R. Yates; Sharon K. Papiernik; Mingxin Guo; Jianying Gan

2006-01-01

313

Testing of an Advanced Liquid Hydrogen Turbopump.  

National Technical Information Service (NTIS)

This paper discusses the testing of an Advanced Liquid Hydrogen Turbopump for a 50,000 pound (222.4 kN) thrust Upper Stage Expander Cycle Engine being developed by Pratt & Whitney Liquid Space Propulsion under contract to the United States Air Force Resea...

L. Chapman G. Crease J. Friant R. Grabowski E. Schmidt

2000-01-01

314

Selective Catalytic Oxidation of Hydrogen Sulfide on Activated Carbons Impregnated with Sodium Hydroxide  

SciTech Connect

Two activated carbons of different origin were impregnated with the solution of sodium hydroxide (NaOH) of various concentrations up to 10 wt %, and the effect of impregnation on the catalytic performance of the carbons was evaluated. The catalytic activity was analyzed in terms of the capacity of carbons for hydrogen sulfide (H2S) conversion and removal from hydrogen-rich fuel streams and the emission times of H2S and the products of its oxidation [e.g., sulfur dioxide (SO2) and carbonyl sulfide (COS)]. The results of impregnation showed a significant improvement in the catalytic activity of both carbons proportional to the amount of NaOH introduced. NaOH introduces hydroxyl groups (OH-) on the surface of the activated carbon that increase its surface reactivity and its interaction with sulfur-containing compounds.

Schwartz, Viviane [ORNL; Baskova, Svetlana [ORNL; Armstrong, Timothy R. [ORNL

2009-01-01

315

Simultaneous adsorption of hydrogen sulfide and carbon dioxide by an aqueous solution of tricalcium phosphate  

SciTech Connect

In the scrubbing of hydrogen sulfide from a gas in the presence of carbon dioxide, the problem of selective scrubbing often arises-the total extraction of hydrogen sulfide with minimal extraction of CO/sub 2/. Scrubbing of H/sub 2/S from natural gases, gasification gases of different fuels, tertiary treatment of exhaust gases from installations producing sulfur by the Claus method, can be cited as industrial examples of this problem. The use of a selective cyclic method of gas scrubbing is expedient for all of these; one of these methods is the method which uses an aqueous solution of tricalcium phosphate (TCP). Some data on gas scrubbing with a TCP solution are reported, but no generalized dependences for the calculation of the individual stages of the process have been given in these studies. The authors attempt here to fill this gap for the stage of simultaneous adsorption of H/sub 2/S and CO/sub 2/.

Golyand, S.M.; Afanse'ev, Y.M.; Gorshkova, T.A.; Rodionov, A.I.; Shklyar, R.L.

1985-02-01

316

Hydrogen Sulfide Gas Treatment by a Chemical?Biological Process: Chemical Absorption and Biological Oxidation Steps  

Microsoft Academic Search

In order to remove high concentrations of hydrogen sulfide (H2S) gas from anaerobic wastewater treatments in livestock farming, a novel process was evaluated for H2S gas abatement involving the combination of chemical absorption and biological oxidation processes. In this study, the extensive experiments evaluating the removal efficiency, capacity, and removal characteristics of H2S gas by the chemical absorption reactor were

2003-01-01

317

Hydrogen sulfide increases calcium-activated potassium (BK) channel activity of rat pituitary tumor cells  

Microsoft Academic Search

Hydrogen sulfide (H2S) is the third gasotransmitter found to be produced endogenously in living cells to exert physiological functions. Large\\u000a conductance (maxi) calcium-activated potassium channels (BK), which play an important role in the regulation of electrical\\u000a activity in many cells, are targets of gasotransmitters. We examined the modulating action of H2S on BK channels from rat GH3 pituitary tumor cells

Guzel F. Sitdikova; Thomas M. Weiger; Anton Hermann

2010-01-01

318

Theoretical Interpretation on Impedance Spectra for Anodic Iron Dissolution in Acidic Solutions Containing Hydrogen Sulfide  

Microsoft Academic Search

Nyquist impedance diagrams for dissolution of iron in acidic solutions with hydrogen sulfide (HâS) display an inductive loop in the fourth quadrant and two capacitive loops in the first quadrant at lower anodic potentials. The charge-transfer resistance (R{sub t}) was larger than polarization resistance (R{sub p}). A general reaction model originating from chemisorption followed by two successive charge-transfer steps was

H. Y. Ma; S. H. Chen; X. L. Cheng; G. Q. Li; H. Q. Yang; S. B. Lei; X. Y. Chen

1998-01-01

319

Hydrogen sulfide is an endogenous modulator of leukocyte-mediated inflammation  

Microsoft Academic Search

Hydrogen sulfide (H2S) is increasingly recognized as an important signaling molecule in the cardiovascular and nervous systems. Recently, H2S do- nors were reported to induce neutrophil apoptosis and to suppress expression of some leukocyte and endothe- lial adhesion molecules. Using rats, we examined the possibility that H2S is an endogenous regulator of key inflammatory events at the leukocyte-endothelial inter- face.

Renata C. O. Zanardo; Vincenzo Brancaleone; Eleonora Distrutti; Stefano Fiorucci; Giuseppe Cirino; John L. Wallace

2006-01-01

320

Operation optimization of Thiobacillus thioparus CH11 biofilter for hydrogen sulfide removal  

Microsoft Academic Search

Members of the autotrophic species, Thiobacillus thioparus CH11, were isolated from swine wastewater and immobilized with Ca-alginate to produce pellet packing materials for a novel biofilter system that controls hydrogen sulfide emission. The effect of operating parameters, including retention time, temperature, and inlet gas concentration, on the removal efficiency and capacity was evaluated. Criteria necessary for a scale-up design of

Ying-Chien Chung; Chihpin Huang; Ching-Ping Tseng

1996-01-01

321

Evidence That Hydrogen Sulfide Exerts Antinociceptive Effects in the Gastrointestinal Tract by Activating KATP Channels  

Microsoft Academic Search

Hydrogen sulfide (H2S) functions as a neuromodulator, but whether it modulates visceral perception and pain is unknown. Cystathionine -synthase (CBS) and cystathionine--lyase (CSE) mediate enzymatic generation of H2S in mammalian cells. Here we have investigated the role of H2S in modulating nociception to colorectal distension, a model that mimics some features of the irritable bowel syndrome. Four graded (0.4-1.6 ml

Eleonora Distrutti; Luca Sediari; Andrea Mencarelli; Barbara Renga; Stefano Orlandi; Elisabetta Antonelli; Fiorenza Roviezzo; Antonio Morelli; Giuseppe Cirino; John L. Wallace; Stefano Fiorucci

2005-01-01

322

Role of hydrogen sulfide in acute pancreatitis and associated lung injury  

Microsoft Academic Search

Hydrogen sulfide (H2S) is a naturally occurring gas with potent vasodilator activity. Cystathionine-?-lyase (CSE) and cystathionine-?-synthase (CBS) utilize L-cysteine as substrate to form H2S. Of these two enzymes, cystathionine-?-lyase (CSE) is believed to be the key enzyme that forms H2S in the cardiovascular system. Whilst H2S has been reported to relax precontracted rat arteries in vitro and to lower blood

Madhav Bhatia; Fei Ling Wong; Di Fu; Hon Yen Lau; Shabbir M. Moochhala; Philip K. Moore

2005-01-01

323

Computational prediction of hydrogen sulfide and methane separation at room temperature by anatase titanium dioxide  

NASA Astrophysics Data System (ADS)

Removal of hydrogen sulfide (H2S) is a key step for biogas purification. Herein, the adsorption of H2S and methane (CH4) on anatase titanium dioxide (TiO2) has been studied by first principle calculations. It is found that TiO2 offers excellent capacity for the H2S/CH4 separation. Using force-field molecular dynamics, this high separation capacity has been examined at room temperature.

Sun, Chenghua

2013-02-01

324

The possible role of hydrogen sulfide on the pathogenesis of spontaneous hypertension in rats  

Microsoft Academic Search

Hydrogen sulfide (H2S) is a newly found modulator in vascular system. This work showed that gene expression of cystathionine ?-lyase (CSE), a H2S generating enzyme, and the activity of CSE in thoracic aorta were suppressed in hypertension rats. The plasma level of H2S also decreased in those rats. Exogenous administration of H2S could increase the plasma level of H2S and

Hui Yan; Junbao Du; Chaoshu Tang

2004-01-01

325

Endogenous hydrogen sulfide contributes to the cardioprotection by metabolic inhibition preconditioning in the rat ventricular myocytes  

Microsoft Academic Search

The possible role of hydrogen sulfide (H2S) in cardioprotection was investigated in isolated rat ventricular myocytes exposed to severe metabolic inhibition (MI) in glucose-free buffer containing 2-deoxy-D-glucose (2-DOG), an inhibitor of glycolysis. Pretreatment (30 min) with NaHS (a H2S donor) at concentrations of 10?5 to 10?4 mol\\/L caused a concentration related increase in cell viability and the ratio of rod-shaped cells.

Ting-Ting Pan; Zhan-Ning Feng; Shiau Wei Lee; Philip Keith Moore; Jin-Song Bian

2006-01-01

326

Production and Actions of Hydrogen Sulfide, a Novel Gaseous Bioactive Substance, in the Kidneys  

Microsoft Academic Search

Hydrogen sulfide (H2S), a novel endogenous gaseous bioactive substance, has recently been implicated in the regulation of cardiovascular and neuronal functions. However, its role in the control of renal function is unknown. In the present study, incubation of renal tissue homogenates with L-cysteine (L-Cys) (as a substrate) produced H2S in a concentration-dependent manner. This H2S production was completely abolished by

Min Xia; Li Chen; Rachel W. Muh; Pin-Lan Li; Ningjun Li

2009-01-01

327

Dynamic change of hydrogen sulfide during global cerebral ischemia–reperfusion and its effect in rats  

Microsoft Academic Search

Hydrogen sulfide (H2S) is a gaseous messenger and serves as an important neuromodulator in central nervous system. In the current study, we investigated the change of H2S and cystathionine ?-synthase (CBS), an H2S-synthesizing enzyme at different time points of reperfusion following global cerebral ischemia in rats, and the effect of exogenous H2S on global cerebral ischemia–reperfusion injury. First, we used

Caili Ren; Ailin Du; Dongliang Li; Jinwen Sui; William G. Mayhan; Honggang Zhao

2010-01-01

328

Hydrogen sulfide may improve the hippocampal damage induced by recurrent febrile seizures in rats  

Microsoft Academic Search

The aim of the present study was to investigate the possible role of hydrogen sulfide (H2S) in the pathogenesis of recurrent febrile seizures (FS) in rats. On a rat model of recurrent FS, the ultrastructure of hippocampal neurons, the plasma level of H2S, the expressions of cystathionine b-synthase (CBS) and c-fos, and the development of mossy fiber sprouting (MFS) in

Ying Han; Jiong Qin; Xingzhi Chang; Zhixian Yang; Xiuying Tang; Junbao Du

2005-01-01

329

Cumulative biochemical effects of repeated subclinical hydrogen sulfide intoxication in mouse brain  

Microsoft Academic Search

Adult female NMRI mice exposed four times to 100 ppm hydrogen sulfide vapour for 2 h at 4-day intervals showed increasing inhibition of the cerebral cytochrome oxidase activity. Cerebral RNA decreased significantly after the fourth exposure. This change was accompanied by the reduced orotic acid uptake in the RNA fraction. At the same time, 2',3'-cyclic nucleotide 3'-phosphohydrolase activity used as

H. Savolainen; R. Tenhunen; E. Elovaara; A. Tossavainen

1980-01-01

330

Measurement of low concentration and nano-quantity hydrogen sulfide in sera using unfunctionalized carbon nanotubes  

Microsoft Academic Search

Hydrogen sulfide (H2S) is produced in small amounts by certain cells in the mammalian body and has a number of biological functions. H2S gas naturally produced by the body is not simply a toxic gas; it could be a vascular dilator and play a physiological role in regulating cardiovascular functions. In order to know the effects of H2S, it is

331

Hydrogen sulfide antagonizes homocysteine-induced neurotoxicity in PC12 cells  

Microsoft Academic Search

Hydrogen sulfide (H2S) has been shown to protect neurons against oxidative stress. Lower levels of H2S as well as accumulation of homocysteine (Hcy), a strong risk of Alzheimer's disease (AD), are reported in the brains of AD patients. The aim of present study is to explore the protection of H2S against Hcy-induced cytotoxicity and apoptosis and the molecular mechanisms underlying

Xiao-Qing Tang; Xin-Tian Shen; Yi-E Huang; Yan-Kai Ren; Rong-Qian Chen; Bi Hu; Jian-Qin He; Wei-Lan Yin; Jin-Hua Xu; Zhi-Sheng Jiang

2010-01-01

332

Neurotoxicological Effects Associated with Short-Term Exposure of Sprague–Dawley Rats to Hydrogen Sulfide  

Microsoft Academic Search

Although hydrogen sulfide (H2S) is a known neurotoxic hazard, only a limited number of experimental animal studies have examined its neurochemical or behavioral effects. Our aim was to determine if short-term inhalation exposure of rats to H2S would result in altered brain catecholamine levels or impaired learning and memory. Three groups of adult male CD rats were tested; two groups

Melanie F Struve; Jennifer N Brisbois; R Arden James; Marianne W Marshall; David C Dorman

2001-01-01

333

Hydrogen sulfide as an effective and specific novel therapy for acute carbon monoxide poisoning  

Microsoft Academic Search

Hydrogen sulfide (H2S) has been recognized as a toxic gas and environment pollutant. So, it is seldom regarded as a therapeutic gas. H2S has been recognized recently as a novel gaseous messenger and serves as an important neuromodulator in the central nervous system. Many researches have been focused on the protective role of H2S in treatment of several diseases. Like

Yong-Peng Yu; Zhen-Guang Li; Dao-Zhen Wang; Xia Zhan; Jing-Hua Shao

2011-01-01

334

Hydrogen sulfide counteracts chlorophyll loss in sweetpotato seedling leaves and alleviates oxidative damage against osmotic stress  

Microsoft Academic Search

In this paper, effect of NaHS, a hydrogen sulfide (H2S) donor on chlorophyll and antioxidant metabolism in seedling leaves of sweetpotato under osmotic stress was investigated.\\u000a With the enhancement of osmotic stress, which was mimicked by PEG-6000, chlorophyll in seedling leaves of sweetpotato (Ipomoea batatas) decreased dramatically. At 15% PEG (w\\/v), chlorophyll concentration reached only 50% compared with that of

Hua Zhang; Yong-Kang Ye; Song-Hua Wang; Jian-Ping Luo; Jun Tang; Dai-Fu Ma

2009-01-01

335

The vasorelaxant effect of hydrogen sulfide is enhanced in streptozotocin-induced diabetic rats  

Microsoft Academic Search

Hydrogen sulfide (H2S) is an endogenous gas which has potent relaxant effect in vascular and nonvascular smooth muscles. In the present study,\\u000a we have investigated how streptozotocin (STZ)-induced diabetes affected the relaxant effect of H2S in rat isolated thoracic aorta and mesenteric and pulmonary arteries. Diabetes was induced by IV injection of STZ (35 mg\\/kg).\\u000a Insulin treatment was applied by using

Merve Denizalti; Turgut Emrah Bozkurt; U?ur Akpulat; Inci Sahin-Erdemli; Nurettin Abac?o?lu

2011-01-01

336

Hydrogen sulfide mediates hypoxia-induced relaxation of trout urinary bladder smooth muscle  

Microsoft Academic Search

Hydrogen sulfide (H2S) is a recently identified gasotransmitter that may mediate hypoxic responses in vascular smooth muscle. H2S also appears to be a signaling molecule in mammalian non-vascular smooth muscle, but its existence and function in non-mammalian non-vascular smooth muscle have not been examined. In the present study we examined H2S production and its physiological effects in urinary bladder from

Ryan A. Dombkowski; Meredith M. Doellman; Sally K. Head; Kenneth R. Olson

2006-01-01

337

Control of hydrogen sulfide emissions using autotrophic denitrification landfill biocovers: engineering applications  

Microsoft Academic Search

Hydrogen sulfide (H2S) emitted from construction and demolition waste landfills has received increasing attention. Besides its unpleasant odor,\\u000a longterm exposure to a very low concentration of H2S can cause a public health issue. In the case of construction and demolition (C&D) waste landfills, where gas collection\\u000a systems are not normally required, the generated H2S is typically not controlled and the

Daoroong Sungthong; Debra R. Reinhart

2011-01-01

338

The influence that protozoa has on hydrogen sulfide oxidation by phototrophic bacteria  

Microsoft Academic Search

These experiments have been performed with a facility for the simulation of summer stagnation conditions in natural water\\u000a bodies. Our experimental results suggest that anaerobic ciliates and flagellates can stimulate hydrogen sulfide oxidation\\u000a and thus the photosynthesis of phototrophic green bacteria in phosphorus deficient media. The phosphorus (as well as nitrogen)\\u000a limitation of hydrobiological processes is most widespread in natural

P. P. Umorin; N. A. Lapteva

2011-01-01

339

Measurement of Hydrogen Sulfide in Beef Cattle Feedlots on the Texas High Plains  

Microsoft Academic Search

Hydrogen Sulfide (H2S) is a product of anaerobic breakdown of organic materials. In enclosed facilities, this can be potentially deadly both to livestock and to human workers. Little is known about H2S emissions from open lot feedyards. Three commercial feedyards in the Texas High Plains were selected for a one-year trial. These were well isolated from other facilities, and were

Marty B. Rhoades; Bobby Dye

340

Selective oxidation of hydrogen sulfide to ammonium thiosulfate and sulfur over vanadium-bismuth oxide catalysts  

Microsoft Academic Search

The selective oxidation of hydrogen sulfide containing excess water and ammonia was studied over vanadium-bismuth mixed oxide catalysts. The investigation was focused on understanding the complex reaction steps and the roles of each metal oxide. Therefore, supported V2O5\\/TiO2, V-Bi-O\\/TiO2 catalysts and a mechanical mixture of V2O5 + Bi2O3 were tested in the reaction. Ammonia reacted either with H2S or SO2,

Young-Gu Cho; Dae-Kwang Park; Dae-Won Park; Hee-Chul Woo; Jong-Shik Chung

2002-01-01

341

Preserving Shipboard AFFF Fire Protection System Performance While Preventing Hydrogen Sulfide Formation  

Microsoft Academic Search

There is a very serious problem aboard US Navy ships from generation of toxic hydrogen sulfide (H2S) in Aqueous Film-Forming Foam (AFFF) solutions used for shipboard fire protection. This is the result of the action of sulfate\\u000a reducing bacteria (SRB) in mixtures of seawater and AFFF, which remain stagnant for significant time periods in shipboard\\u000a fire protection system piping. Similar

Ronald S. Sheinson; Bradley A. Williams

2008-01-01

342

Rate controlling processes for crack growth in hydrogen sulfide for an alsl 4340 steel  

Microsoft Academic Search

Parallel fracture mechanics and surface chemistry studies were carried out to develop further understanding of environment\\u000a assisted subcritical crack growth in high strength steels. The kinetics of crack growth for an AISI 4340 steel (tempered at\\u000a 477 K) in high purity hydrogen sulfide have been determined as a function of pressure at room temperature and as a function\\u000a of temperature

M. Lu; P. S. Pao; T. W. Weir; G. W. Simmons; R. P. Wei

1981-01-01

343

Inhibition of Hydrogen Sulfide Generation Contributes to Gastric Injury Caused by Anti-Inflammatory Nonsteroidal Drugs  

Microsoft Academic Search

Background & Aims: Hydrogen sulfide (H2S), an endog- enous gaseous mediator that causes vasodilation, is generated in mammalian tissues by cystathionine -synthase (CBS) and cystathionine--lyase (CSE). Here, we have investigated the role of H2S in a rodent model of nonsteroidal anti-inflammatory drug (NSAID) gastropathy. Methods: Rats were given acetyl salycilic acid (ASA) or an NSAID alone or in combination with

STEFANO FIORUCCI; ELISABETTA ANTONELLI; ELEONORA DISTRUTTI; GIOVANNI RIZZO; ANDREA MENCARELLI; STEFANO ORLANDI; RENATA ZANARDO; BARBARA RENGA; MOSES DI SANTE; ANTONIO MORELLI; GIUSEPPE CIRINO; JOHN L. WALLACE

2005-01-01

344

Inhibition of Hydrogen Sulfide Generation Contributes to 1-Methy-4-Phenylpyridinium IonInduced Neurotoxicity  

Microsoft Academic Search

Reactive oxygen species (ROS) overproduction contributes to the neurotoxicity of 1-methy-4-phenylpyridinium ion (MPP+). Increasing studies have shown that hydrogen sulfide (H2S) is an endogenous antioxidant gas. We have hypothesized that MPP+-caused neurotoxicity may involve the imbalance of proportion to this endogenous protective antioxidant gas. The aim of this\\u000a study is to evaluate whether MPP+ disturbs H2S synthesis in PC12 cells,

Xiao-Qing Tang; Li-Li Fan; Yu-Juan Li; Xin-Tian Shen; Yuan-Yuan Zhuan; Jian-Qin He; Jin-Hua Xu; Bi Hu; Yuan-Jian Li

2011-01-01

345

A model for the pH-regulated oscillatory reaction between hydrogen peroxide and sulfide ion  

SciTech Connect

A proposed empirical law model based on the H{sup +} autocatalysis in the reaction HS{sup -} + 4H{sub 2}O{sub 2} yielding SO{sub 4}{sup 2-} + 4H{sub 2}O + H{sup +} for the pH-regulated oscillatory reaction between sulfide and hydrogen peroxide. This results from the faster oxidation of the protonated sulfite intermediate by H{sub 2}O{sub 2}. 25 refs., 7 figs., 1 tab.

Rabai, G.; Orban, M.; Epstein, I.R. [Brandeis Univ., Waltham, MA (United States)

1992-06-25

346

Hydrogen sulfide (H 2S) and sour gas effects on the eye. A historical perspective  

Microsoft Academic Search

The toxicology of hydrogen sulfide (H2S) and sour gas on the eye has a long history beginning at least with Ramazzini's observations [Ramazzini B. Diseases of Workers—De Morbis Artificum Diatriba—1713. Wright WC (trans). New York, C. Hafner Publishing Co Inc.; 1964. 98–99 pp.]. In contrast, a recent review by Alberta Health and Wellness (AHW Report) concluded that there is little

Timothy William Lambert; Verona Marie Goodwin; Dennis Stefani; Lisa Strosher

2006-01-01

347

Hydrogen sulfide and the probabilities of inhalation through a tympanic membrane defect  

Microsoft Academic Search

The authors conclude that workers with tympanic membrane defects (perforated eardrums) should not be excluded from working in atmospheres containing concentrations of hydrogen sulfide (HâS). Several existing requirements and recommendations exclude workers with perforated eardrums from working in or around HâS. Such protective measures stem from the belief that HâS can enter the body through the perforation in sufficient measure

Richard Ronk; Mary Kay White

1985-01-01

348

Simulation of the Process of Biological Removal of Hydrogen Sulfide from Gas  

Microsoft Academic Search

Hydrogen sulfide (H2S) is considered as one of the most noxious industrial gases. Its removal from natural gas is particularly required for reasons of health, odour problems, safety and corrosivity problems. H2S causes an irritating, rotten egg smell in concentrations above 1ppm, and at concentrations above 10ppm the toxicological exposure limits are exceeded. Many methods have been developed over the

H. Alfadala; G. V. Rex Reklaitis; M. M. El-Halwagi; E. M. Elkanzi

349

Measurement of low concentration and nano-quantity hydrogen sulfide in sera using unfunctionalized carbon nanotubes  

Microsoft Academic Search

Hydrogen sulfide (H2S) is produced in small amounts by certain cells in the mammalian body and has a number of biological functions. H2S gas naturally produced by the body is not simply a toxic gas; it could be a vascular dilator and play a physiological role in regulating cardiovascular functions. In order to know the effects of H2S, it is

X. C. Wu; W. J. Zhang; R. Sammynaiken; Q. H. Meng; D. Q. Wu; Q. Yang; W. Yang; Edwin M. Zhang; R. Wang

2009-01-01

350

Sorption of ammonia and hydrogen sulfide by cation-substituted palygorskite  

SciTech Connect

The replacement of exchange cations of natural palygorskite by Cu/sup 2 +/, Co/sup 2 +/, Al/sup 3 +/, or Fe/sup 3 +/ cations produces significant increases in the capacity of the cation-substituted samples for the uptake of ammonia and hydrogen sulfide. The sorption mechanism has been examined in relation to the molecules of these substances; the cation-exchanged and natural samples of palygorskite have been ranked in order of sorption properties under equilibrium and dynamic conditions.

Kats, B.M.; Tarasevich, Yu.I.; Malinovskii, E.K.; Dlubovskii, R.M.

1986-09-01

351

Hazardous peak concentrations of hydrogen sulfide gas related to the sewage purification process.  

PubMed

The concentration of hydrogen sulfide in the atmosphere of a sewage purification plant in Norway was studied. Continuous measurements over several 3-week periods showed that the concentrations generally were lower than 2 ppm, but peak concentrations over 100 ppm were discovered. Rapid onset and decline characterized these peak concentrations, which occurred at regular intervals. Through evaluation of the time pattern of these peaks compared with plant operations, a specific process was identified as the likely causative factor of the spikes. Through simple remedial actions the hydrogen sulfide concentration associated with this activity was reduced from above 100 ppm to less than 2 ppm. Olfactory fatigue to hydrogen sulfide and strong offensive odors from other compounds in the sewage makes smell ineffective for signaling high concentrations. Peak concentrations may therefore pass unnoticed unless detected with continuous measuring equipment. The risk for exposure may be reduced by enclosing processes and through the use of spot extraction ventilation in areas with compacted anaerobic waste material. PMID:10772623

Søstrand, P; Tvedt, B; Eduard, W; Bye, E; Heldal, K

352

Biological hydrogen sulfide production in an ethanol-lactate fed fluidized-bed bioreactor.  

PubMed

Sulfate-reducing fluidized-bed bioreactor (FBR) fed with ethanol-lactate mixture was operated at 35 degrees C for 540 days to assess mine wastewater treatment, biological hydrogen sulfide production capacity and acetate oxidation kinetics. During the mine wastewater treatment period with synthetic wastewater, the sulfate reduction rate was 62 mmol SO(4)(2-)L(-1)d(-1) and Fe and Zn precipitation rates were 11 mmol Fe L(-1)d(-1) and 1 mmol Zn L(-1)d(-1). After this, the hydrogen sulfide production was optimized, resulting in sulfate reduction rate of 100 mmol SO(4)(2-)L(-1)d(-1) and H(2)S production rate of 73.2 mmol H(2)SL(-1)d(-1). The limiting step in the H(2)S production was the rate of acetate oxidation, being 50 mmol acetate L(-1)d(-1). Therefore, FBR batch assays were designed to determine the acetate oxidation kinetics, and following kinetic parameters were obtained: K(m) of 63 micromol L(-1) and V(max) of 0.76 micromol acetate g VSS(-1)min(-1). The present study demonstrates high-rate hydrogen sulfide production and high-rate mine wastewater treatment with ethanol and lactate fed fluidized-bed bioreactor. PMID:19716290

Nevatalo, Laura M; Mäkinen, Annukka E; Kaksonen, Anna H; Puhakka, Jaakko A

2009-08-27

353

Hydrogen Sulfide Therapy Attenuates the Inflammatory Response in a Porcine Model of Myocardial Ischemia - Reperfusion Injury  

PubMed Central

Introduction Hydrogen sulfide (H2S) is produced endogenously in response to myocardial ischemia and thought to be cardioprotective. The mechanism underlying this protection has yet to be fully elucidated, but may be related sulfide’s ability to limit inflammation. This study investigates the cardioprotection provided by exogenous H2S, and its potential anti-inflammatory mechanism of action. Methods The mid-LAD coronary artery in 14 Yorkshire swine was acutely occluded for 60 minutes, followed by reperfusion for 120 minutes. Controls(7) received placebo, and treatment animals(7) received sulfide 10 minutes prior to and throughout reperfusion. Hemodynamic and functional measurements were obtained. Evans blue and TTC staining identified the area-at-risk and infarction. Coronary microvascular reactivity was assessed. Tissue was assayed for myeloperoxidase activity and pro-inflammatory cytokines. Results Pre-I/R hemodynamics were similar between groups, whereas post-I/R mean arterial pressure (mmHg) was reduced by 28.7±5.0 in controls vs. 6.7±6.2 in treatment animals (p=0.03). +LV dP/dt (mmHg/sec) was reduced by 1325±455 in controls vs. 416±207 in treatment animals (p=0.002). Segmental shortening in the area-at-risk was better in treatment animals. Infarct size (% of area-at-risk) in controls was 41.0±7.8% vs. 21.2±2.5% in the treated group (p=0.036). Tissue levels of IL-6, IL-8, and TNF? and MPO activity decreased in the treatment group. Treated animals demonstrated improved microvascular reactivity. Conclusions Therapeutic sulfide provides protection in response to I/R injury, improving myocardial function, reducing infarct size, and improving coronary microvascular reactivity, potentially through its anti-inflammatory properties. Exogenous sulfide may have therapeutic utility in clinical settings in which I/R injury is encountered.

Sodha, Neel R.; Clements, Richard T.; Feng, Jun; Liu, Yuhong; Bianchi, Cesario; Horvath, Eszter M.; Szabo, Csaba; Stahl, Gregory L.; Sellke, Frank W.

2009-01-01

354

Low-power, fast, selective nanoparticle-based hydrogen sulfide gas sensor  

NASA Astrophysics Data System (ADS)

We demonstrate a small, low-cost, low-power, highly sensitive, and selective nanomaterials-based gas sensor. A network of tungsten oxide nanoparticles is heated by an on-chip microhotplate while the conductance of the network is monitored. The device can be heated with short pulses, thereby drastically lowering the power consumption, without diminishing the sensor response. The sensor shows high sensitivity to hydrogen sulfide and does not have significant cross sensitivities to hydrogen, water, or methane, gases likely to be present in operation. A sensing mechanism is proposed, and its effect on electronic properties is discussed.

Sussman, Allen; Mickelson, William; Zettl, A.

2013-03-01

355

Protective and Detrimental Effects of Sodium Sulfide and Hydrogen Sulfide in Murine Ventilator-induced Lung Injury  

PubMed Central

Background The antiinflammatory effects of hydrogen sulfide (H2S) and sodium sulfide (Na2S) treatment may prevent acute lung injury induced by high tidal volume (HVT) ventilation. However, lung protection may be limited by direct pulmonary toxicity associated with H2S inhalation. Therefore, the authors tested whether the inhalation of H2S or intravascular Na2S treatment can protect against ventilator-induced lung injury in mice. Methods Anesthetized mice continuously inhaled 0, 1, 5, or 60 ppm H2S or received a single bolus infusion of Na2S (0.55 mg/kg) or vehicle and were then subjected to HVT (40 ml/kg) ventilation lasting 4 h (n = 4–8 per group). Results HVT ventilation increased the concentrations of protein and interleukin-6 in bronchoalveolar lavage fluid, contributing to reduced respiratory compliance and impaired arterial oxygenation, and caused death from lung injury and pulmonary edema. Inhalation of 1 or 5 ppm H2S during HVT ventilation did not alter lung injury, but inhalation of 60 ppm H2S accelerated the development of ventilator-induced lung injury and enhanced the pulmonary expression of the chemoattractant CXCL-2 and the leukocyte adhesion molecules CD11b and L-selectin. In contrast, pretreatment with Na2S attenuated the expression of CXCL-2 and CD11b during HVT ventilation and reduced pulmonary edema. Moreover, Na2S enhanced the pulmonary expression of Nrf2-dependent antioxidant genes (NQO1, GPX2, and GST-A4) and prevented oxidative stress-induced depletion of glutathione in lung tissue. Conclusions The data suggest that systemic intravascular treatment with Na2S represents a novel therapeutic strategy to prevent both ventilator-induced lung injury and pulmonary glutathione depletion by activating Nrf2-dependent antioxidant gene transcription.

Francis, Roland C.; Vaporidi, Katerina; Bloch, Kenneth D.; Ichinose, Fumito; Zapol, Warren M.

2013-01-01

356

Low-volatility polar organic solvents for sulfur dioxide, hydrogen sulfide, and carbonyl sulfide  

SciTech Connect

The solubility of SO/sub 2/, H/sub 2/S, and COS in several phosphoric and phthalic acid esters, poly(ethylene glycols), and poly(ethylene glycol) dialkyl ethers was measured at temperatures between 20 and 100/sup 0/C and pressures between 0.01 and 1 bar. Henry's and equilibrium constants were determined from experimental solubility data as a function of temperature. Furthermore, selection criteria for the tested organic liquids, like viscosity and vapor pressure data, are also reported.

Hartel, G.H.

1985-01-01

357

Multicomponent sulfides as narrow gap hydrogen evolution photocatalysts.  

PubMed

A series of mixed crystals composed of Cu(2)ZnSnS(4), Ag(2)ZnSnS(4) and ZnS was prepared by co-precipitation of the corresponding metal ions in aqueous sodium sulfide followed by annealing in a sulfur atmosphere. Ideal solid solutions of Cu(2)ZnSnS(4) and Ag(2)ZnSnS(4) with a kesterite structure ((Cu(x)Ag(1-x))(2)ZnSnS(4) (0 ?x? 1)) were successfully obtained by this procedure, as confirmed by their X-ray diffraction (XRD) patterns and energy-diffuse X-ray (EDX) analyses. On the other hand, the solubility of ZnS in these kesterite compounds was found to be limited: the upper limit of the ratio of ZnS to (Cu(x)Ag(1-x))(2)ZnSnS(4) was less than 0.1, regardless of the Cu-Ag ratio in (Cu(x)Ag(1-x))(2)ZnSnS(4). Based on the results for dependence of their photoabsorption properties on atomic compositions, a plausible band structure is discussed. Evaluation of the photocatalytic activity for H(2) evolution of these mixed crystals from an aqueous solution containing S(2-) and SO(3)(2-) ions upon loading Ru catalysts under simulated solar radiation (AM 1.5) revealed that active compounds for this reaction should contain both dissolved ZnS and Ag components. The dissolved ZnS in (Cu(x)Ag(1-x))(2)ZnSnS(4) gave upward shifts of their conduction band edges. Moreover, the presence of Ag in the solid solution provided n-type conductivity, leading to efficient migration of photogenerated electrons to the surface to induce water reduction into H(2). PMID:20852813

Ikeda, Shigeru; Nakamura, Takayuki; Harada, Takashi; Matsumura, Michio

2010-09-20

358

Plasma-chemical treatment of hydrogen sulfide in natural gas processing. Final report, May 1991--December 1992  

SciTech Connect

A new process for the treatment of hydrogen sulfide waste that uses microwave plasma-chemical technology has been under development in Russia and the United States. Whereas the present waste-treatment technology, at best, only recovers sulfur, this novel process recovers both hydrogen and sulfur by dissociating hydrogen sulfide in a plasma by means of a microwave or radio-frequency reactor. A research project has been undertaken to determine the suitability of the plasma process in natural gas processing applications. The experiments tested acid-gas compositions with 30--65% carbon dioxide, 0--7% water, and 0--0.2% of a standard mixture of pipeline gas. The balance gas in all cases was hydrogen sulfide. The reactor pressure for the experiments was 50 torr, and the microwave power was 1.0 kW. Conversions of hydrogen sulfide ranged from 80 to 100%, while 35--50% of the carbon dioxide was converted to carbon monoxide. This conversion of carbon dioxide resulted in a loss of hydrogen production and an energy loss from a hydrogen sulfide waste-treatment perspective. Tests of a direct natural gas treatment concept showed that hydrocarbon losses were unacceptably high; consequently, the concept would not be economically viable.

Harkness, J.B.L.; Doctor, R.D. [Argonne National Lab., IL (United States)

1993-05-01

359

Recovery of hydrogen from hydrogen sulfide. [Reaction of molten Pb and HâS  

Microsoft Academic Search

The combination of the following two exothermic reactions was studied with the purpose of recovering Hâ from HâS formed in acid leaching of sulfide ores, direct reduction of metal sulfides with Hâ or desulfurization of crude oils: Pb(1) + HâS = PbS(s) + Hâ; PbS(s) + Oâ = Pb(1) + SOâ. In the kinetic study of the recovery of Hâ,

H. Kiuchi; T. Tanaka

1977-01-01

360

Modeling leaks from liquid hydrogen storage systems.  

SciTech Connect

This report documents a series of models for describing intended and unintended discharges from liquid hydrogen storage systems. Typically these systems store hydrogen in the saturated state at approximately five to ten atmospheres. Some of models discussed here are equilibrium-based models that make use of the NIST thermodynamic models to specify the states of multiphase hydrogen and air-hydrogen mixtures. Two types of discharges are considered: slow leaks where hydrogen enters the ambient at atmospheric pressure and fast leaks where the hydrogen flow is usually choked and expands into the ambient through an underexpanded jet. In order to avoid the complexities of supersonic flow, a single Mach disk model is proposed for fast leaks that are choked. The velocity and state of hydrogen downstream of the Mach disk leads to a more tractable subsonic boundary condition. However, the hydrogen temperature exiting all leaks (fast or slow, from saturated liquid or saturated vapor) is approximately 20.4 K. At these temperatures, any entrained air would likely condense or even freeze leading to an air-hydrogen mixture that cannot be characterized by the REFPROP subroutines. For this reason a plug flow entrainment model is proposed to treat a short zone of initial entrainment and heating. The model predicts the quantity of entrained air required to bring the air-hydrogen mixture to a temperature of approximately 65 K at one atmosphere. At this temperature the mixture can be treated as a mixture of ideal gases and is much more amenable to modeling with Gaussian entrainment models and CFD codes. A Gaussian entrainment model is formulated to predict the trajectory and properties of a cold hydrogen jet leaking into ambient air. The model shows that similarity between two jets depends on the densimetric Froude number, density ratio and initial hydrogen concentration.

Winters, William Stanley, Jr.

2009-01-01

361

Liquid Hydrogen Target Experience at SLAC  

SciTech Connect

Liquid hydrogen targets have played a vital role in the physics program at SLAC for the past 40 years. These targets have ranged from small 'beer can' targets to the 1.5 m long E158 target that was capable of absorbing up to 800 W without any significant density changes. Successful use of these targets has required the development of thin-wall designs, liquid hydrogen pumps, remote positioning and alignment systems, safety systems, control and data acquisition systems, cryogenic cooling circuits and heat exchangers. Detailed operating procedures have been created to ensure safety and operational reliability.This paper surveys the evolution of liquid hydrogen targets at SLAC and discusses advances in several of the enabling technologies that made these targets possible.

Weisend, J. G. II; Boyce, R.; Candia, A.; Kaminskas, W.; Mark, J.; Racine, M.; St Lorant, S.; Weber, T. [Stanford Linear Accelerator Center, Menlo Park, CA 94025 (United States); Arnold, R.; Bosted, P. [University of Massachusetts, Amherst, MA 01003 (United States); Carr, R.; Gao, J.; Jones, C. E.; McKeown, R. [California Institute of Technology, Pasadena, CA 91125 (United States)

2006-04-27

362

Liquid Hydrogen Target Experience at SLAC  

SciTech Connect

Liquid hydrogen targets have played a vital role in the physics program at SLAC for the past 40 years. These targets have ranged from small ''beer can'' targets to the 1.5 m long E158 target that was capable of absorbing up to 800 W without any significant density changes. Successful use of these targets has required the development of thin wall designs, liquid hydrogen pumps, remote positioning and alignment systems, safety systems, control and data acquisition systems, cryogenic cooling circuits and heat exchangers. Detailed operating procedures have been created to ensure safety and operational reliability. This paper surveys the evolution of liquid hydrogen targets at SLAC and discusses advances in several of the enabling technologies that made these targets possible.

Weisend, J.G.; Boyce, R.; Candia, A.; Kaminskas, W.; Mark, J.; Racine, M.; St. Lorant, S.; Weber, T.; /SLAC; Arnold, R.; Bosted, P.; /Massachusetts U., Amherst; Carr, R.; Gao, J.; Jones, C.E.; McKeown, R.; /Caltech

2005-08-29

363

Effect of sodium sulfide on hydrogen absorption of Ti-6% Al-4% V alloy  

SciTech Connect

The hydrogenation inhibitive effect of sodium sulfide on Ti-6% Al-4% V alloy (UNS R56400) in aqueous sulfuric acid solution (H{sub 2}SO{sub 4[aq]}) was investigated qualitatively and quantitatively using optical microscopy, x-ray diffraction (XRD), and glow-discharge spectrometry (GDS). Introduction of Na{sub 2}S into the electrolyte resulted in an obvious inhibitive effect of hydrogen absorption on as-received (covered with a thin thermal oxide film < 0.5 {micro}m) and abraded specimens (free of thermal oxide film) irrespective of applied current density and operating period. The contrary effect of Na{sub 2}S on Ti-6% Al-4% V alloy vs ferrous alloys could have resulted from the fact that molecular hydrogen sulfide, which adsorbed on the titanium surface as on the iron surface, facilitated formation of a thin layer of {var_epsilon} titanium hydride (TiH{sub 2}). TiH{sub 2} effectively retarded ingress of hydrogen.

Wu, T.I. [Tatung Inst. of Tech., Taipei (Taiwan, Province of China). Dept. of Materials Engineering; Liu, C.T.; Wu, J.K. [National Taiwan Ocean Univ., Keelung (Taiwan, Province of China). Dept. of Marine Materials Engineering

1997-05-01

364

Simulation of spray drying with reaction: Absorption of hydrogen sulfide in ammoniacal solution of zinc chloride  

SciTech Connect

Absorption of hydrogen sulfide gas in ammoniacal solution of zinc chloride is accompanied with an instantaneous chemical reaction forming zinc sulfide precipitates. Such reactions are most suited for operation of spray drying with reaction. A mathematical model for the system which incorporates chemical reaction, heat, mass and momentum transfer has been proposed. It is assumed that the gases and the spray is considered monodisperse for sake of simplicity. The differential equations derived for the model have been solved as an initial value problem using the Runge-Kutta method. The variations of temperature, humidity, droplet diameter, moisture content and concentrations of reactants are predicted along the length of the column and compared with experimental data.

Chander, H.; Ghosh, P.K. (National Physical Lab., New Delhi (India)); Baveja, K.K.; Dhingra, S.C. (Indian Inst. of Tech., New Delhi (India))

1993-01-01

365

Redox biology of hydrogen sulfide: Implications for physiology, pathophysiology, and pharmacology?  

PubMed Central

Hydrogen sulfide (H2S) has emerged as a critical mediator of multiple physiological processes in mammalian systems. The pathways involved in the production, consumption, and mechanism of action of H2S appear to be sensitive to alterations in the cellular redox state and O2 tension. Indeed, the catabolism of H2S through a putative oxidation pathway, the sulfide quinone oxido-reductase system, is highly dependent on O2 tension. Dysregulation of H2S homeostasis has also been implicated in numerous pathological conditions and diseases. In this review, the chemistry and the main physiological actions of H2S are presented. Some examples highlighting the cytoprotective actions of H2S within the context of cardiovascular disease are also reported. Elucidation of the redox biology of H2S will enable the development of new pharmacological agents based on this intriguing new redox cellular signal.

Stein, Asaf; Bailey, Shannon M.

2013-01-01

366

Molybdate and tungstate doped porous carbons as hydrogen peroxide activation catalysts for sulfide oxidations  

SciTech Connect

Molybdenum and tungsten compounds activate hydrogen peroxide in homogeneous solution to oxidize a variety of substrates including organic sulfides. MoO{sub 4}{sup 2-} is also a remarkable nucleophile with a second-order rate constant 35 times that of phosphate for the hydrolysis of p-nitro-phenylacetate in spite of phosphate having a 1000-fold larger basicity. This research demonstrates that absorbent carbons, pore filled with molybdate and tungstate ions, are very effective catalysts for the oxidation of sulfides with 30% aqueous H{sub 2}O{sub 2}. The novel feature of these catalysts is that they carry out oxidations under basic conditions where G-agents would also undergo catalyzed hydrolysis.

Drago, R.S.; Burns, D.S. [Univ. of Florida, Gainesville, FL (United States)

1997-03-01

367

Rotational spectroscopic study of carbonyl sulfide solvated with hydrogen molecules.  

PubMed

Rotational spectra of small-sized (H(2))(N)-OCS clusters with N = 2-7 were measured using a pulsed-jet Fourier transform microwave spectrometer. These include spectra of pure (para-H(2))(N)-OCS clusters, pure (ortho-H(2))(N)-OCS clusters, and mixed ortho-H(2) and para-H(2) containing clusters. The rotational lines of ortho-H(2) molecules containing clusters show proton spin-proton spin hyperfine structure, and the pattern evolves as the number of ortho-H(2) molecules in the cluster increases. Various isotopologues of the clusters were investigated, including those with O(13)CS, OC(33)S, OC(34)S, and O(13)C(34)S. Nuclear quadrupole hyperfine structures of rotational transitions were observed for (33)S (nuclear spin quantum number I = 3/2) containing isotopologues. The (33)S nuclear quadrupole coupling constants are compared to the corresponding constant of the OCS monomer and those of the He(N)-OCS clusters. The assignment of the number of solvating hydrogen molecules N is supported by the analyses of the proton spin-proton spin hyperfine structures of the mixed clusters, the dependence of line intensities on sample conditions (pressure and concentrations), and the agreement of the (para-H(2))(N)-OCS and (ortho-H(2))(N)-OCS rotational constants with those from a previous infrared study [J. Tang and A. R. W. McKellar, J. Chem. Phys. 121, 3087 (2004)]. PMID:19045151

Michaud, Julie M; Jäger, Wolfgang

2008-10-14

368

Endurance materials for hydrogen sulfide splitting in electrolytic cell  

NASA Astrophysics Data System (ADS)

This study describes the development of a novel thin membrane exchange assembly (MEA) from a solid acid material, cesium hydrogen sulfate (CsHSO 4), and from a composite anode electrocatalyst for electrolytic splitting of (100%) H2S feed content gas operating at 135 kPa and 150°C. A new class of anode electrocatalyst with the general composition, RuO 2/CoS2, and an improved proton conductor, CsHSO4, have shown great stability and desired properties at typical operating conditions. This configuration demonstrated stable electrochemical operation for 24 h with a (100%) H2S fuel stream at 423 K. This same system showed a maximum current density of (19 mA/cm2) at 900 mV. The performance of this new anode electrocatalyst when compared to that of Pt black investigated in a previous study showed an overall superiority in application. We have achieved a 30% reduction in the overall system performance by fabricating a thin (200 microm) CsHSO4 electrolyte, which reduced the whole MEA thickness from 2.3 mm to 500 microm. The result of permeability measurements proved that this thin solid electrolyte is impermeable to H 2S gas and physical integrity was preserved throughout the experimental period. Further resistance losses were compensated by using a high energy planetary milling system to enhance the ionic conductivity of CsHSO4 . The difference in stability and electrochemical performance of these cells compared to that of Pt anode based systems is directly attributable to the anode materials developed in this project. Factorial experiments were used to characterize the effect of controllable process variables (electrolyte thickness, time, age of the electrolyte) on the cell current density and interfacial polarization resistances. As expected, cell current density and interfacial polarization resistances were a function of electrolyte thickness and age. Nevertheless, the effect of electrolyte thickness has a more prominent effect on the measured parameters. In addition, these experiments were used to identify regions of optimum system performance. Tafel plots were constructed to investigate the kinetic behavior of various anode based electrocatalysts. Exchange current densities, which are directly a measure of the electrochemical reaction, increased with RuO2/CoS 2-based anodes. These experiments also suggested that high levels of feed utilization were possible using these materials. This was an impressive result considering the drastic improvement in electrochemical performance, current density, and sulfur tolerance compared to the other anode configurations.

Mbah, Jonathan Chinwendu

369

Critical fields of liquid superconducting metallic hydrogen  

Microsoft Academic Search

Liquid metallic hydrogen, in a fully dissociated state, is predicted at certain densities to pass from dirty to clean and from type II to type I superconducting behavior as temperature is lowered. Previously announced in STAR as N82-29374

J. Jaffe; N. W. Ashcroft

1983-01-01

370

Small, High-Pressure Liquid Hydrogen Turbopump.  

National Technical Information Service (NTIS)

A high pressure, liquid hydrogen turbopump was designed, fabricated, and tested to a maximum speed of 9739 rad/s and a maximum pump discharge pressure of 2861 N/sq. cm. The approaches used in the analysis and design of the turbopump are described, and fab...

A. Csomor R. Sutton

1977-01-01

371

ABSORPTION SPECTROSCOPY IN LIQUID ANHYDROUS HYDROGEN FLUORIDE  

Microsoft Academic Search

A literature survey was made in conjunction with the study of transition ; metal complexes in liquid anhydrous hydrogen fluoride. Consideration is given to ; the effect of the solvent as a coordinating agent, coordinating properties of ; ligands, and the ability of the metal to form complexes. This review considers ; primarily the infrared, visible, and ultraviolet spectra. 25

Tulumello

1960-01-01

372

Refueling equipment for liquid hydrogen vehicles  

Microsoft Academic Search

We are introducing a newly developed mobile filling station for liquid hydrogen for refuelling cars and buses. With a combined approval as a road tanker and as a filling station, it can be used for demonstration purposes at various places. Due to the employment of lately developed components like solenoid valves, couplings and steerings, the refuelling operation could be made

W. Hettinger; F. Michel; P. Ott; F. Theissen

1998-01-01

373

Effect of Hydrogen Sulfide on Sympathetic Neurotransmission and Catecholamine Levels in Isolated Porcine Iris-Ciliary Body  

Microsoft Academic Search

In the present study, we investigated the pharmacological action of hydrogen sulfide (H2S, using sodium hydrosulfide, NaHS, and\\/or sodium sulfide, Na2S as donors) on sympathetic neurotransmission from isolated, superfused porcine iris-ciliary bodies. We also examined the\\u000a effect of H2S on norepinephrine (NE), dopamine and epinephrine concentrations in isolated porcine anterior uvea. Release of [3H]NE was triggered by electrical field stimulation

Kaustubh H. Kulkarni; Emmanuel M. Monjok; Robert Zeyssig; Ghislaine Kouamou; Odelia N. Bongmba; Catherine A. Opere; Ya Fatou Njie; Sunny E. Ohia

2009-01-01

374

System of Hydrogen-Powered Vehicles with Liquid Organic Hydrides.  

National Technical Information Service (NTIS)

A complete system for storing and using energy in the form of hydrogen organic liquid is discussed. The recyclable liquid carrier is methylcyclohexane (liq). (The system is called MTH for methylcyclohexane, Toluene, hydrogen). The dehydrogenation reaction...

M. Taube

1981-01-01

375

Novel Composite Hydrogen-Permeable Membranes for Non-Thermal Plasma Reactors for the Decomposition of Hydrogen Sulfide. Quarterly Report April 1-June 30, 2004.  

National Technical Information Service (NTIS)

The goal of this experimental project is to design and fabricate a reactor and membrane test cell to dissociate hydrogen sulfide (H2S) in a non-thermal plasma and recover hydrogen (H2) through a superpermeable multi-layer membrane. Superpermeability of hy...

M. D. Argyle J. F. Ackerman S. Muknahallipatna J. C. Hamann S. Legowski

2004-01-01

376

Oxidation of hydrogen sulfide by hydrous Fe(III) oxides in seawater  

Microsoft Academic Search

The rate of oxidation of hydrogen sulfide by hydrous Fe(III) oxides has been determined as a function of pH (4.0–8.5), temperature (5–45 °C) and ionic strength (0–4 m) in seawater. The effect of the major ions (Ca2+, Mg2+, SO42?, B(OH)4? and HCO4?), minor solutes (PO43?, Si(OH)4, NH4+ and Mn2+) and some organic ligands (EDTA, Tris, oxalate, humic acid and fulvic

Wensheng Yao; Frank J. Millero

1996-01-01

377

Hydrogen sulfide and sodium nitroprusside compete to activate/deactivate MMPs in bone tissue homogenates  

PubMed Central

Background Bone microvascular remodeling is the primary predictor of bone structure and function. Remodeling by its very nature implies synthesis and degradation of the extracellular matrix. Normally, 50% of total protein in the vessel wall is elastin. During remodeling, elastin is degraded by specialized matrix metalloproteinases (MMPs). Because the turnover of elastin is 1000-fold slower than that of collagen, most of the elastin is replaced by stiffer collagen. Stiffer vessels impose pressure on the aortic valve, causing regurgitation and increased pulse pressure. On the other hand, high MMP activity will cause vascular dilatation, leading to aneurysm. Therefore, balanced constitutive remodeling is necessary for adequate bone structure and function. Interestingly, collagen-degrading MMPs are involved in various pathological conditions, including osteoporosis, osteoarthritis, and cardiovascular disease. Sodium nitroprusside is a nitric oxide donor that could potentially alter MMP activity via vasodilation in vivo, but can also produce peroxynitrite, which activates MMPs by combining with superoxide. Moreover, hydrogen sulfide is a known antioxidant as well as a vasodilator, and is also speculated to contribute directly to MMP activity. We hypothesized that hydrogen sulfide reduced activity of MMP in ex vivo bone tissue homogenates and that sodium nitroprusside would increase MMP activity in vitro. Methods We surgically removed the tibia and femur from anesthetized mice, and prepared bone tissue homogenates using a mortar and pestle, measured the protein concentration with a spectrophotometer, and detected MMP activity using gelatin gel zymography. Results Our data showed increased MMP activity at a sodium nitroprusside concentration of 1 ?M, and MMP activity increased exponentially. There was a decrease in MMP activity with increasing hydrogen sulfide, beginning at 16 ?M (P < 0.01) and continuing to 40 ?M. Moreover, sodium nitroprusside 3 ?M was able to overcome the decrease in MMP activity that occurred with hydrogen sulfide 40 ?M; this resulted in a more pronounced exponential increase in MMP activity. Conclusion There are several substances that can potentially be used to decrease MMP activity and to alleviate pathological remodeling by MMPs.

Vacek, Thomas P; Qipshidze, Natia; Tyagi, Suresh C

2013-01-01

378

Hydrogen Sulfide Attenuates Carbon Tetrachloride-Induced Hepatotoxicity, Liver Cirrhosis and Portal Hypertension in Rats  

Microsoft Academic Search

BackgroundHydrogen sulfide (H2S) displays vasodilative, anti-oxidative, anti-inflammatory and cytoprotective activities. Impaired production of H2S contributes to the increased intrahepatic resistance in cirrhotic livers. The study aimed to investigate the roles of H2S in carbon tetrachloride (CCl4)-induced hepatotoxicity, cirrhosis and portal hypertension.Methods and FindingsSodium hydrosulfide (NaHS), a donor of H2S, and DL-propargylglycine (PAG), an irreversible inhibitor of cystathionine ?-lyase (CSE), were

Gang Tan; Shangha Pan; Jie Li; Xuesong Dong; Kai Kang; Mingyan Zhao; Xian Jiang; Jagat R. Kanwar; Haiquan Qiao; Hongchi Jiang; Xueying Sun; Antonio Bertoletti

2011-01-01

379

Corrosion in the divisions for vacuum-carbonate removal of hydrogen sulfide from coke oven gas  

SciTech Connect

A description was given of the factors effecting the corrosion of equipment involved in the removal of hydrogen sulfide from coke oven gas. It was noted that heat exchangers with water as the cooling agent were particularly susceptible to corrosion. The factors effecting the corrosiveness of this water were detailed. These included the oxygen given off during heating, the pH of the water, the velocity of the water in the exchanger, and the material of construction of the exchanger. Also, a discussion of the effect of the design of the exchanger on its ease of corrosion was given. In particular, the location of inlets and outlets was discussed.

Stetsenko, E.Y.; Gutman, V.L.

1982-01-01

380

Cyclooxygenase2 mediates the delayed cardioprotection induced by hydrogen sulfide preconditioning in isolated rat cardiomyocytes  

Microsoft Academic Search

We previously reported that hydrogen sulfide (H2S) preconditioning (SP) produces cardioprotection in isolated rat cardiomyocytes. The present study was designed to determine\\u000a the involvement of cyclooxygenase-2 (COX-2) in the SP-induced delayed cardioprotection. Isolated cardiac myocytes were treated\\u000a with NaHS (100 ?M, a H2S donor) for 30 min and then cultured for 20 h followed by ischemia\\/reperfusion insults. SP significantly increased cell viability,\\u000a percentage

Li-Fang Hu; Ting-Ting Pan; Kay Li Neo; Qian Chen Yong; Jin-Song Bian

2008-01-01

381

Evaluation of thiosulfate as a substitute for hydrogen sulfide in sour corrosion fatigue studies  

NASA Astrophysics Data System (ADS)

This work evaluates the possibility of replacing hydrogen sulfide (H 2S) with thiosulfate anion (S2O32- ) in sour corrosion fatigue studies. H2S increases the corrosion fatigue crack growth rate (FCGR) and can be present in carbon steel risers and flowlines used in off-shore oil production. Corrosion tests with gaseous H2S require special facilities with safety features, because H2S is a toxic and flammable gas. The possibility of replacing H2S with S2O32-, a non-toxic anion, for studying stress corrosion cracking of stainless and carbon steels in H2S solutions was first proposed by Tsujikawa et al. ( Tsujikawa et al., Corrosion, 1993. 49(5): p. 409-419). In this dissertation, Tsujikawa work will be extended to sour corrosion fatigue of carbon steels. H2S testing is often conducted in deareated condition to avoid oxygen reaction with sulfide that yields sulfur and to mimic oil production conditions. Nitrogen deareation was also adopted in S2O3 2- testing, and gas exiting the cell was forced through a sodium hydroxide trap. Measurements of the sulfide content of this trap were used to estimate the partial pressure of H2S in nitrogen, and Henry's law was used to estimate the content of H2S in the solution in the cell. H2S was produced by a redox reaction of S2O 32-, which required electrons from carbon steel corrosion. This reaction is spontaneous at the open circuit potential of steel. Therefore, H2S concentration was expected to be maximum at the steel surface, and this concentration was estimated by a mass balance analysis. Carbon steel specimens exposed to S2O32- containing solutions developed a film on their surface, composed by iron sulfide and cementite. The film was not passivating and a good conductor of electrons. Hydrogen permeation experiments proved that this film controls the rate of hydrogen absorption of steels exposed to thiosulfate containing solutions. The absorption of hydrogen in S2O3 2- solutions was compared with the absorption of hydrogen in solutions saturated with different H2S partial pressures. The partial pressure was selected so that the concentration of H2S in the solution saturated with the gas would be the same as that reached in the surface of steel freely corroding in the thiosulfate solution. For solutions obtained by bubbling H2S, the rate of hydrogen absorption increased with the partial pressure of the gas, but the rate of hydrogen absorption reached a maximum at 10-3 M S2O3 2-, despite the surface concentration of H2S increased with the concentration of S2O32-. This effect was associated with the formation of thicker films, which inhibited the absorption of hydrogen. FCGR were evaluated at constant stress intensity factor range. Crack length was monitored in-situ by the direct current potential drop (DCPD) method. FCGR increased with the partial pressure of H2S in nitrogen. FCGR was controlled not only by the amount of hydrogen present in the steel, but also by inhibiting contributions like crack closure and crack tip blunting. FCGR in dilute thiosulfate solutions was near that measured in a solution saturated with a partial pressure of H2S equal to 0.56 kPa, in accord with hydrogen permeation results.

Kappes, Mariano Alberto

382

Conditions under which cracks occur in modified 13% chromium steel in wet hydrogen sulfide environments  

SciTech Connect

Occurrence of cracks in an API 13% Cr steel, modified 13% Cr steel, and duplex stainless steel were compared in various wet, mild hydrogen sulfide (H{sub 2}S) environments. The conditions under which cracks occurred in the modified 13% Cr steel in oil and gas production environments were made clear. No cracks occurred if pH > depassivation pH (pH{sub d}) and redox potential of sulfur (E{sub S(red/ax)}) < pitting potential (V{sub c}). Hydrogen embrittlement-type cracks occurred in pH > Ph{sub d} and E{sub S(red/ax)} > V{sub c}. The pH inside the pit decreased drastically and hydrogen embrittlement occurred. Cracks of the hydrogen embrittlement type occurred if pH < pH{sub d} and threshold hydrogen concentration under which cracks occur (H{sub th}) < hydrogen concentration in steel (H{sub 0}). No cracks occurred if pH < pH{sub d} and H{sub th} > H{sub 0}.

Hara, T.; Asahi, H.

2000-05-01

383

Effect of hydrogen sulfide on aqueous corrosion of commercially pure Al 99.5  

SciTech Connect

Recently, there has been interest in the use of aluminum alloys as possible alternatives to carbon steel for handling oilfield products, such as brines with dissolved carbon dioxide (CO{sub 2}) and H{sub 2}S. The effect of hydrogen sulfide on the corrosion behavior of commercially pure aluminum (DIN Al 99.5 [AA 1050A]) in chloride solutions containing carbon dioxide, bicarbonate, and copper ions at 30 C and 80 C was investigated using natural immersion corrosion tests, cathodic polarization, and scanning electron microscopy. The highest corrosion rates were observed in solutions containing Cu{sup 2+} but with no H{sub 2}S content because of copper deposition on the metal surface. Significant pitting occurred at 80 C. With H{sub 2}S in the solution, pitting corrosion was eliminated by removal of Cu{sup 2+} and other deleterious heavy-metal ion impurities form the solution in the form of insoluble sulfides. If H{sub 2}S was introduced after the copper deposited on the aluminum surface, no inhibiting effect was detected at 30 C, but a degree of inhibition still was observed at 80 C, presumably because the deposited copper was converted more effectively into copper sulfide at the higher temperature.

Bjoergum, A.; Sigurdsson, H. [SINTEF Corrosion Center, Trondheim (Norway); Nisancioglu, K. [Norwegian Inst. of Tech., Trondheim (Norway). Dept. of Electrochemistry

1995-08-01

384

Oxidation of organic sulfides by electrophilically-activated hydrogen peroxide: The catalytic ability of methylrhenium trioxide  

SciTech Connect

A family of organic sulfides was oxidized to the corresponding sulfoxides by hydrogen peroxide. Such reactions are, however, very slow and meaningless in practice without an effective catalyst. The oxidation was successfully catalyzed by CH{sub 3}ReO{sub 3}, a water-soluble organometallic oxide. A kinetic study was carried out in 1:1 (v/v) acetonitrile-water at pH 1 and at 25{degrees}C. The kinetics can be resolved into two steps. First, H{sub 2}O{sub 2} and CH{sub 3}ReO{sub 3} react to form 1:1 and 2:1 rhenium peroxides, denoted as A and B, respectively. In the second step A and B react with the substrate forming the product. The rate constants for the various steps of these reactions were evaluated using steady-state techniques and are on the order of 10{sup 3} L mol{sup {minus}1} s{sup {minus}1} for aryl methyl sulfides and 10{sup 4} L mol{sup {minus}1} s{sup {minus}1} for dialkyl sulfides. Both A and B are reactive, A moreso than B. The kinetic results point to a mechanism that involves the nucleophilic attack of the sulfur atom on a peroxide oxygen of the rhenium peroxides. This formulation is consistent with the accelerating effects of electron-donating substituents.

Vassell, K.A.; Espenson, J.H. [Iowa State Univ., Ames, IA (United States)

1994-11-23

385

14 CFR 420.66 - Separation distance requirements for storage of hydrogen peroxide, hydrazine, and liquid hydrogen...  

Code of Federal Regulations, 2013 CFR

...distance requirements for storage of hydrogen peroxide, hydrazine, and liquid hydrogen...requirements for storage of hydrogen peroxide, hydrazine, and liquid hydrogen...hazard facility storing: (1) Hydrogen peroxide in concentrations of...

2013-01-01

386

49 CFR 179.102-17 - Hydrogen chloride, refrigerated liquid.  

Code of Federal Regulations, 2010 CFR

... § 179.102-17 Hydrogen chloride, refrigerated liquid. Each tank car used to transport hydrogen chloride, refrigerated...the transportation of hydrogen chloride, refrigerated...applicable authorized tank car specification...

2010-10-01

387

49 CFR 179.102-17 - Hydrogen chloride, refrigerated liquid.  

Code of Federal Regulations, 2010 CFR

... § 179.102-17 Hydrogen chloride, refrigerated liquid. Each tank car used to transport hydrogen chloride, refrigerated...the transportation of hydrogen chloride, refrigerated...applicable authorized tank car specification...

2009-10-01

388

Ab initio molecular dynamics simulation of liquid hydrogen fluoride  

Microsoft Academic Search

We have performed an ab initio molecular dynamics (MD) simulation of the structure of liquid hydrogen fluoride. Our results exhibit a strong contraction of the hydrogen bond in going from the gas to the liquid phase. The local structure of the liquid resembles that of the solid with the appearance of short lived hydrogen-bonded zig-zag chains. We have also studied

Ursula Röthlisberger; Michele Parrinello

1997-01-01

389

An approach to global rovibrational analysis based on anharmonic ladder operators: Application to hydrogen selenide and hydrogen sulfide  

NASA Astrophysics Data System (ADS)

A formalism to model the ro-vibrational spectrum of triatomic asymmetric top molecules is presented. The quantum mechanical ro-vibrational kinetic and potential energy function is considered as a Taylor expansion in internal coordinates of Morse local oscillators. Thereafter, local Morse coordinates and momenta are expanded in terms of Morse Potential ladder operators. Only polyad-conserving terms are considered. Expansions of the kinetic and potential energies of the ro-vibrational Hamiltonian are considered up to sextic terms. The resulting Hamiltonian was diagonalized using a symmetry-adapted basis, generated by the eigenfunction method ( J.Q.Chen, Group Representation Theory for Physicists,World Scientific, 1989; R. Lemus, 2003 Mol.Phys., 101 2511-2528.). The model is applied to hydrogen sulfide (H_2S) and hydrogen selenide (H_2Se).

Perez-Bernal, F.; Carvajal, M.; Alvarez-Bajo, O.

2011-05-01

390

On-line monitoring of gas-phase bioreactors for biogas treatment: hydrogen sulfide and sulfide analysis by automated flow systems  

Microsoft Academic Search

Biogas is produced by biological processes under anaerobic conditions and may contain up to 20,000 ppmv hydrogen sulfide (H2S), a corrosive substance that attacks power engines and can affect the health of the industrial staff. H2S must be removed from the biogas, especially in co-generation facilities where the biogas is burnt for energy production.\\u000a Nowadays, biofiltration is being studied and considered

Rosa Redondo; Vinicius Cunha Machado; Mireia Baeza; Javier Lafuente; David Gabriel

2008-01-01

391

Measurement, analysis, and modeling of hydrogen sulfide emissions from a swine facility in North Carolina  

NASA Astrophysics Data System (ADS)

Annual global source contributions of sulfur compounds to the natural atmospheric environment are estimated to be 142 x 106 tons. Although not quantified, volatilization from animal wastes may be an important source of gaseous reduced sulfur compounds. Hydrogen sulfide (H2S) is a colorless gas emitted during decomposition of hog manure that produces an offensive "rotten egg" odor. Once released into the atmosphere, H 2S is oxidized and the eventual byproduct, sulfuric acid, may combine with other atmospheric constituents to form aerosol products such as ammonium bisulfate and ammonium sulfate. In recent years, confined animal feeding operations (CAFOs) have increased in size, resulting in more geographically concentrated areas of animals and, subsequently, animal waste. In North Carolina and across the southeastern United States anaerobic waste treatment lagoons are traditionally used to store and treat hog excreta at commercial hog farms. Currently, no state regulations exist for H2S gaseous emissions from animal production facilities in North Carolina and the amount of H2S being emitted into the atmosphere from these potential sources is widely unknown. In response to the need for data, this research initiative has been undertaken in an effort to quantify emissions of H2S from swine CAFOs. An experimental study was conducted at a commercial swine farm in eastern North Carolina to measure hydrogen sulfide emissions from a hog housing unit utilizing a mechanical fan ventilation system and from an on-site waste storage treatment lagoon. A dynamic flow-through chamber system was employed to make lagoon flux measurements. Semi-continuous measurements were made over a one-year period (2004-2005) for a few days during each of the four predominant seasons in order to assess diurnal and temporal variability in emissions. Fan rpm from the barn was continuously measured and flow rates were calculated in order to accurately assess gaseous emissions from the system. Temperature at the fan outlet and static pressure inside the barn were measured. Lagoon samples were collected daily and analyzed for sulfide content. Lagoon parameters, temperature and pH; and atmospheric environmental parameters, ambient temperature, relative humidity, wind speed and ambient hydrogen sulfide concentration were concurrently monitored on-site. The highest barn emissions were measured during the winter and appeared to be related to the age and weight of the animals housed inside the barn. (Abstract shortened by UMI.)

Blunden, Jessica

392

Occurrence and distribution of color and hydrogen sulfide in water of the principal artesian aquifers in the Valdosta area, Georgia  

USGS Publications Warehouse

Hydrogen sulfide and color occur in objectionable amounts in ground water from the principal artesian aquifer in the Valdosta , Ga., area. Generally, water from wells south of Valdosta is high in hydrogen sulfide; water from wells north of the city is high in color. Water with high sulfate is likely to be a problem in wells deeper than about 540 ft. Heavy pumpage concentrated in a small area may cause high-sulfate water to migrate vertically upward into shallower wells. (Woodard-USGS)

Krause, Richard E.

1976-01-01

393

Equilibrium hydrate formation conditions for hydrogen sulfide, carbon dioxide, and ethane in aqueous solutions of ethylene glycol and sodium chloride  

SciTech Connect

Natural gas components such as hydrogen sulfide, carbon dioxide, and ethane form gas hydrates of structure I under suitable temperature and pressure conditions. Information on such conditions is vital to the oil and gas industry in order to design and operate processing equipment and pipelines so that hydrate formation is avoided. Incipient equilibrium hydrate formation conditions for hydrogen sulfide, carbon dioxide, and ethane in aqueous solutions of ethylene glycol and sodium chloride were experimentally obtained in the temperature range 264--290 K and the pressure range 0.23--3.18 MPa. A variable-volume sapphire cell was used for the measurements.

Majumdar, A.; Mahmoodaghdam, E.; Bishnoi, P.R.

2000-02-01

394

Reduction of Ferrylmyoglobin by Hydrogen Sulfide. Kinetics in Relation to Meat Greening.  

PubMed

The hypervalent meat pigment ferrylmyoglobin, MbFe(IV)?O, characteristic for oxidatively stressed meat and known to initiate protein cross-linking, was found to be reduced by hydrogen sulfide to yield sulfmyoglobin. Horse heart myoglobin, void of cysteine, was used to avoid possible interference from protein thiols. For aqueous solution, the reactions were found to be second-order, and an apparent acid catalysis could be quantitatively accounted for in terms of a fast reaction between protonated ferrylmyoglobin, MbFe(IV)?O,H(+), and hydrogen sulfide, H2S (k2 = (2.5 ± 0.1) × 10(6) L mol(-1) s(-1) for 25.0 °C, ionic strengh 0.067, dominating for pH < 4), and a slow reaction between MbFe(IV)?O and HS(-) (k2 = (1.0 ± 0.7) × 10(4) L mol(-1) s(-1) for 25.0 °C, ionic strengh 0.067, dominating for pH > 7). For meat pH, a reaction via the transition state {MbFe(IV)?O···H···HS}(?) contributed significantly, and this reaction appeared almost independent of temperature with an apparent energy of activation of 2.1 ± 0.7 kJ mol(-1) at pH 7.4, as a result of compensation among activation energies and temperature influence on pKa values explaining low temperature greening of meat. PMID:23425699

Libardi, Silvia H; Pindstrup, Helene; Cardoso, Daniel R; Skibsted, Leif H

2013-03-01

395

Dynamic change of hydrogen sulfide after traumatic brain injury and its effect in mice.  

PubMed

Hydrogen sulfide (H2S) is a lipid-soluble, endogenously produced gaseous messenger molecule collectively known as gasotransmitter. Over the last several decades, gasotransmitters have emerged as potent cytoprotective mediators in various models of tissue and cellular injury. In this study, we performed a weight-drop traumatic brain injury (TBI) model in adult mice and investigated changes of H2S and its possible role in the pathogenesis after TBI. Expression of Cystathionine-?-synthase (CBS) mRNA as H2S-producing enzymes in mouse brain was determined by reverse transcriptase-polymerase chain reaction (RT-PCR). From the results of RT-PCR, it was found that the expression of CBS was down-regulated in mouse brain cortex and hippocampus after brain injury. Western blot analysis revealed that CBS was present in normal mouse brain cortex and the hippocampus. It gradually decreased, reached its lowest level and then increased. Hydrogen sulfide in the cortex and hippocampus exhibited dynamic changes after brain injury, in parallel with CBS mRNA and protein expression. Moreover, pretreatment with the H2S donor (NaHS) could protect the neuron against the injury induced by TBI. Noticeably, the H2S donor NaHS could reduce TBI-induced injury assessed with lesion volume. These data suggested that H2S may have a therapeutic potential against neuron damage. PMID:23325453

Zhang, Mingyang; Shan, Haiyan; Wang, Tao; Liu, Weili; Wang, Yaoqi; Wang, Long; Zhang, Lu; Chang, Pan; Dong, Wenwen; Chen, Xiping; Tao, Luyang

2013-01-17

396

Impact of methane and hydrogen sulfide on atmospheric ozone at the Permian-Triassic boundary  

NASA Astrophysics Data System (ADS)

We discuss model experiments valid for the Permian-Triassic boundary in which we explore the impact of changes in tropospheric methane concentration. For scenarios relevant to methane clathrate release, we consider surface methane concentration with values up to 5000 times its preindustrial concentration. We employ a comprehensive three-dimensional tropospheric-stratospheric model with chemistry that allows for the feedbacks between chemistry and climate. We show that stratospheric ozone starts collapsing for methane surface concentrations of the order of 1000 times their preindustrial concentration. At 5000 times, more than half of the total ozone column has disappeared. As the methane lifetime never reaches more than 50 years, this perturbation can only be short-lived. We show he addition of large hydrogen sulfide emissions (from an anoxic ocean) can provide the chemical sink for the hydroxyl radical (OH) and make the methane perturbation much more long-lived. However, the hydrogen sulfide itself does not seem to exert much influence on stratospheric ozone.

Lamarque, J.; Kiehl, J.; Shields, C.; Kinnison, D.

2006-12-01

397

Solubility of hydrogen sulfide in water + monoethanolamine + 2-amino-2-methyl-1-propanol  

SciTech Connect

Alkanolamine aqueous solutions are widely used in gas treating processes to remove acid gases, such as CO[sub 2] and H[sub 2]S, from natural, refinery, and synthesis gas streams. The solubilities of hydrogen sulfide in water (1) + monoethanolamine (2) + 2-amino-2-methyl-1-propanol (3) have been measured at 40, 60, 80, and 100 C and at partial pressures of hydrogen sulfide ranging from 1.0 to 180 kPa. The ternary mixtures studied were [omega][sub 2] = 0, [omega][sub 3] = 0.3; [omega][sub 2] = 0.06, [omega][sub 3] = 0.24; [omega][sub 2] = 0.12, [omega][sub 3] = 0.18; [omega][sub 2] = 0.18, [omega][sub 3] = 0.12; and [omega][sub 2] = 0.24, [omega][sub 3] = 0.06 where [omega] is the mass fraction. The model of Kent and Eisenberg has been extended to represent the solubility of H[sub 2]S in the ternary mixtures. The model reasonably reproduces the equilibrium partial pressure of H[sub 2]S above the ternary mixtures, not only over a temperature range from 40 to 100 C, but also at various compositions of the components in the ternary mixture.

Li, M.H.; Chang, B.C. (Chung Yuan Christian Univ., Chung Li (Taiwan, Province of China). Dept. of Chemical Engineering)

1994-04-01

398

Catalytic hydrogenation of coal-derived liquids  

SciTech Connect

It is the objective of this research to convert coal to clean distillate fuels. This program will be limited to research on the product of PAMCO's solvent refined coal (SRC). The SRC will be heated and pumped, with and without solvent, into a catalytic reactor in the presence of hydrogen and other reducing gases. Variables to be investigated will include temperature, pressure, space velocity, hydrogen-to-oil ratio and chemical nature of the solvent. The catalysts to be studied will include nickel molybdate and sulfide, nickel tungstate and other combinations on carriers such as mordanites and other molecular sieved types. The work on the development of catalysts capable of converting solvent refined coal, SRC-II, into a feedstock suitable for a conventional petroleum refinery was continued. This requires a process which reduces the nitrogen content from the 1.17% in SRC-II to at least as low as 0.3%. Four catalysts were fabricated and evaluated. A cobalt, molybdenum, nickel, tungsten metal loading was made on a molecular sieve base possessing 88.9A average pore diameter. It produced specification product before and after burnoff with air. Three cobalt molybdate catalysts of different metal loadings were fabricated on three different pore diameter bases, 88.9A, 156.5A and 186.2A. Specification grade denitrogenation and regeneration was accomplished although all the results are not yet in. A blank run with no metal loading had no merit as a denitrogenation catalyst.

Berg, L.; McCandless, F.P.

1980-03-28

399

On-line monitoring of gas-phase bioreactors for biogas treatment: hydrogen sulfide and sulfide analysis by automated flow systems.  

PubMed

Biogas is produced by biological processes under anaerobic conditions and may contain up to 20,000 ppm(v) hydrogen sulfide (H(2)S), a corrosive substance that attacks power engines and can affect the health of the industrial staff. H(2)S must be removed from the biogas, especially in co-generation facilities where the biogas is burnt for energy production. Nowadays, biofiltration is being studied and considered as an interesting alternative for removing H(2)S from the biogas besides classical chemical processes. The novelty of this work is the design and construction of an automated H(2)S on-line analyser to assess the composition of the liquid and gas phases of gas-phase bioreactors. The analyser is made of two parallel flow configurations which share the same detection device. The first configuration is a single-channel flow injection analyser (FIA) to detect S(2-) in the liquid phase. The second configuration is a continuous flow analyser (CFA) with a gaseous diffusion step (GD-CFA) for detecting H(2)S in the gas phase. The diffusion step enables separation of the H(2)S((g)) from the sample and its conversion into a detectable chemical species (S(2-)). S(2-) detection was performed with an Ag(2)S ion-selective electrode (ISE) selective to S(2-)(aq). The main response parameters of the FIA system are a linear range between 3 x 10(-5) and 1 x 10(-1) mol L(-1) S(2-) (0.61-3,200 mg L(-1)), with a sensitivity of 27.9 mV decade(-1) and a detection limit of 1.93 x 10(-5) mol L(-1) S(2-). The GD-CFA configuration presents a linear range between 400 and 10,000 ppm(v) H(2)S((g)) with a sensitivity of 26.1 mV decade(-1) and a detection limit of 245 ppm(v) H(2)S. The proposed analyser was used by analysing real gas and liquid samples with optimal results at a full-scale biotrickling filter for biogas treatment at a municipal wastewater treatment plant. PMID:18297275

Redondo, Rosa; Machado, Vinicius Cunha; Baeza, Mireia; Lafuente, Javier; Gabriel, David

2008-02-23

400

Hydrogen sulfide removal from coal gas by the metal-ferrite sorbents made from the heavy metal wastewater sludge.  

PubMed

The metal-ferrite (chromium-ferrite and zinc-ferrite) sorbents made from the heavy metal wastewater sludge have been developed for the hydrogen sulfide removal from coal gas. The high temperature absorption of hydrogen sulfide from coal gas with the metal-ferrite sorbent in a fixed bed reactor was conducted in this study. The metal-ferrite powders were the products of the ferrite process for the heavy metal wastewater treatment. The porosity analysis results show that the number of micropores of the sorbents after sulfidation and regeneration process decreases and the average pore size increases due to the acute endothermic and exothermic reactions during the sulfidation-regeneration process. The FeS, ZnS, and MnS peaks are observed on the sulfided sorbents, and the chromium extraction of the CFR6 can fulfill the emission standard of Taiwan EPA. The suitable sulfidation temperature range for chromium-ferrite sorbent is at 500-600 degrees C. In addition, effects of various concentrations of H2 and CO were also conducted in the present work at different temperatures. By increasing the H2 concentration, the sulfur sorption capacity of the sorbent decreases and an adverse result is observed in the case of increasing CO concentration. This can be explained via water-shift reaction. PMID:18440697

Tseng, Ting Ke; Chang, Han Ching; Chu, Hsin; Chen, Hung Ta

2008-03-20

401

Effect of sulfide removal on sulfate reduction at pH 5 in a hydrogen fed gas-lift bioreactor.  

PubMed

Biotechnological treatment of sulfate- and metal-ionscontaining acidic wastewaters from mining and metallurgical activities utilizes sulfate-reducing bacteria to produce sulfide that can subsequently precipitate metal ions. Reducing sulfate at a low pH has several advantages above neutrophilic sulfate reduction. This study describes the effect of sulfide removal on the reactor performance and microbial community in a high-rate sulfidogenic gas-lift bioreactor fed with hydrogen at a controlled internal pH of 5. Under sulfide removal conditions, 99% of the sulfate was converted at a hydraulic retention time of 24 h, reaching a volumetric activity as high as 51 mmol sulfate/l/d. Under nonsulfide removal conditions, <25% of the sulfate was converted at a hydraulic retention time of 24 h reaching volumetric activities of <13mmol sulfate/l/d. The absence of sulfide removal at a hydraulic retention time of 24 h resulted in an average H2S concentration of 18.2 mM (584 mg S/l). The incomplete sulfate removal was probably due to sulfide inhibition. Molecular phylogenetic analysis identified 11 separate 16S rRNA bands under sulfide stripping conditions, whereas under nonsulfide removal conditions only 4 separate 16S rRNA bands were found. This shows that a less diverse population was found in the presence of a high sulfide concentration. PMID:19047826

Bijmans, Martijn F M; Dopson, Mark; Ennin, Frederick; Lens, Piet N L; Buisman, Cees J N

2008-11-01

402

The influence of hydrogen sulfide-to-hydrogen partial pressure ratio on the sulfidization of Pd and 70 mol% Pd-Cu membranes  

SciTech Connect

The influence of H2S-to-H2 partial pressure ratio on the sulfidization of Pd and 70 mol% Pd–Cu membrane alloys was studied using various H2S-containing gas mixtures. The Pd membranes exposed to various H2S mixtures were in very good agreement with the thermodynamic calculations used in this study, resisting sulfidization when exposed to H2S-to-H2 ratios below the equilibrium value predicted for Pd4S formation, and experiencing sulfidization when exposed to ratios above the equilibrium values. The 70 mol% Pd–Cu membranes, however, exhibited deviations from the predicted values, resisting sulfidization at some conditions close to the equilibrium values at which sulfidization was expected, and experiencing sulfidization at some conditions at which resistance was expected. This phenomenon was attributed to deviations of the Pd–Cu alloy from ideality, probably due to Cu segregation at the membrane surface.

Iyoha, O.; Enick, R.M.; Killmeyer, R.P.; Morreale, B.D.

2007-11-15

403

The influence of hydrogen sulfide-to-hydrogen partial pressure ratio on the sulfidization of Pd and 70 mol% Pd–Cu membranes  

SciTech Connect

The influence of H2S-to-H2 partial pressure ratio on the sulfidization of Pd and 70 mol% Pd–Cu membrane alloys was studied using various H2Scontaining gas mixtures. The Pd membranes exposed to various H2S mixtures were in very good agreement with the thermodynamic calculations used in this study, resisting sulfidization when exposed to H2S-to-H2 ratios below the equilibrium value predicted for Pd4S formation, and experiencing sulfidization when exposed to ratios above the equilibrium values. The 70 mol% Pd–Cu membranes, however, exhibited deviations from the predicted values, resisting sulfidization at some conditions close to the equilibrium values at which sulfidization was expected, and experiencing sulfidization at some conditions at which resistance was expected. This phenomenon was attributed to deviations of the Pd–Cu alloy from ideality, probably due to Cu segregation at the membrane surface.

Iyoha, O.; Enick, R.M.; Killmeyer, R.P.; Morreale, B.

2007-11-15

404

Organic sulfur compounds resulting from the interaction of iron sulfide, hydrogen sulfide and carbon dioxide in an anaerobic aqueous environment.  

PubMed

The reaction of iron sulfide (FeS) with H2S in water, in presence of CO2 under anaerobic conditions was found to yield H2 and a variety of organic sulfur compounds, mainly thiols and small amounts of CS2 and dimethyldisulfide. The same compounds were produced when H2S was replaced by HCl, in the H2S-generating system FeS/HCl/CO2. The identification of the products was confirmed by GC-MS analyses and the incorporation of H2 in the organic sulfur compounds was demonstrated by experiments in which all hydrogen compounds were replaced by deuterium compounds. Generation of H2 and the synthesis of thiols were both dependent upon the relative abundance of FeS and HCl or H2S, i.e. the FeS/HCl- or FeS/H2S-proportions. Whether thiols or CS2 were formed as the main products depended also on the FeS/HCl-ratio: All conditions which create a H2 deficiency were found to initiate a proportional increase in the amount of CS2. The quantities of H2 and thiols generated depended on temperature: the production of H2 was significantly accelerated from 50 degrees C onward and thiol synthesis above 75 degrees C. The yield of thiols increased with the amount of FeS and HCl (H2S), given a certain FeS/HCl-ratio and a surplus of CO2. A deficiency of CO2 results in lower thiol synthesis. The end product, pyrite (FeS2), was found to appear as a silvery granular layer floating on the aqueous surface. The identity of the thiols was confirmed by mass spectrometry, and the reduction of CO2 demonstrated by the determination of deuterium incorporation with DCl and D2O. The described reactions can principally proceed under the conditions comparable to those obtaining around submarine hydrothermal vents, or the global situation about 4 billion years ago, before the dawn of life, and could replace the need for a reducing atmosphere on the primitive earth. PMID:11536750

Heinen, W; Lauwers, A M

1996-04-01

405

Single Membrane Reactor Configuration for Separation of Hydrogen, Carbon Dioxide and Hydrogen Sulfide  

Microsoft Academic Search

The objective of the project was to develop a novel complementary membrane reactor process that can consolidate two or more downstream unit operations of a coal gasification system into a single module for production of a pure stream of hydrogen and a pure stream of carbon dioxide. The overall goals were to achieve higher hydrogen production efficiencies, lower capital costs

Micheal Roberts; Robert Zabransky; Shain Doong; Jerry Lin

2008-01-01

406

Hydrogen sulfide (H2S) and sour gas effects on the eye. A historical perspective.  

PubMed

The toxicology of hydrogen sulfide (H(2)S) and sour gas on the eye has a long history beginning at least with Ramazzini's observations [Ramazzini B. Diseases of Workers--De Morbis Artificum Diatriba--1713. Wright WC (trans). New York, C. Hafner Publishing Co Inc.; 1964. 98-99 pp.]. In contrast, a recent review by Alberta Health and Wellness (AHW Report) concluded that there is little evidence of eye irritation following short-term exposures to H(2)S at concentrations up to 100ppm and that the H(2)S literature on the eye is a series of unsubstantiated claims reproduced in review articles dating back to the 1930s [Alberta Health and Wellness (AHW report). Health effects associated with short-term exposure to low levels of hydrogen sulfide: a technical review, Alberta Health and Wellness, October 2002, 81pp.]. In this paper, we evaluated this claim through a historical review of the toxicology of the eye. Ramazzini noted the effects of sewer gas on the eye [Ramazzini B. Diseases of Workers--De Morbis Artificum Diatriba--1713. Wright WC (trans). New York, C. Hafner Publishing Co Inc. 1964. 98-99 pp.]. Lehmann experimentally showed eye effects in men at 70-90ppm H(2)S and also in animals [Lehmann K. Experimentalle Studien uber den Einfluss technisch und hygienisch wichtiger Gase und Dampfe auf den Organismus. Arch Hyg 1892;14:135-189]. In 1923, Sayers, Mitchell and Yant reported eye effects in animals and men at 50ppm H(2)S. Barthelemy showed eye effects in animals and men at 20ppm H(2)S [Barthelemy HL. Ten years' experience with industrial hygiene in connection with the manufacture of viscose rayon. J Ind Hyg Toxicol 1939;21:141-51]. Masure experimentally showed that H(2)S is the causative agent of eye impacts in animals and men [Masure R. La Keratoconjunctivite des filatures de viscose; etude clinique and experiementale. Rev Belge Pathol 1950;20:297-341]. Michal upon microscopic examination of the rat's cornea, found nuclear pyknosis, edema and separation of cells in the eye following exposures for 3h at 36ppm H(2)S [Michal FV. Eye lesions caused by hydrogen sulfide. Cesk Ophthalmol 1950;6;5-8]. In 1975, in Alberta, irreversible eye damage and photophobia were experimentally produced in calves exposed to 20ppm H(2)S for 1week [Nordstrom GA. A study of calf response of ammonia and hydrogen sulfide gases. Thesis, University of Alberta, Department of Agricultural Engineering, Edmonton Alberta; 1975, 218 pp.]. Alberta Environmental Centre documented clinical irritation of the eye at 40ppm H(2)S in 6 hours in rats [Alberta Environmental Centre. Morphological observations in rats exposed for six hours to an atmosphere of 0, 56, or 420mg/m(3) hydrogen sulfide. AECV86-A1. Alberta Environmental Centre, Vegreville, Alberta; 1986b. 28 pp.]. In two sour gas blow-outs in Alberta, in the early 1980s, eye injury was documented in humans and animals at 0.5 ppm H(2)S. Community studies in the United States, Europe and New Zealand suggest that acute exposure to 25ppb H(2)S is the lowest concentration to irritate the eyes; with chronic exposure, serious eye effects are suggested. In contrast to the conclusion, all of the studies, except one, cited in the AHW Report indicate toxic effects on the eye below 100ppm H(2)S [Alberta Health and Wellness (AHW report). Health effects associated with short-term exposure to low levels of hydrogen sulfide (H(2)S): a technical review, Alberta Health and Wellness, October 2002, 81pp.]. In addition, the AHW Report (2002) mis-presented two studies as 'clinical studies', claiming they reported no evidence of eye effects in humans from 2 and 30 ppm H(2)S for 30-40 minutes [Alberta Health and Wellness (AHW report). Health effects associated with short-term exposure to low levels of hydrogen sulfide (H(2)S): a technical review, Alberta Health and Wellness, October 2002, 81pp.]. PMID:16650463

Lambert, Timothy William; Goodwin, Verona Marie; Stefani, Dennis; Strosher, Lisa

2006-05-02

407

High P\\/T phase and volumetric behavior of coal liquid constituents. (Quarterly technical progress report), January 1April 1, 1984. [6 gases in hydrogen-dibenzofuran and in hydrogen-g-methylanthracene  

Microsoft Academic Search

A sophisticated perturbation chromatography technique has been used to study the vapor-liquid equilibrium behavior of six light gases in two hydrogen-coal liquid model compounds systems. Infinite-dilution K values are reported for methane, ethane, propane, n-butane, carbon dioxide and hydrogen sulfide in: (1) hydrogen-dibenzofuran system at 373.2 and 398.2°K and up to 6 MPa; and (2) hydrogen-g-methylanthracene systems at 373.2, 398.2,

Kobayshi

1984-01-01

408

Deuterium tracer studies on hydrotreating catalysts-isotopic exchange between hydrogen and hydrogen sulfide on sulfided NiMo/Al{sub 2}O{sub 3}  

SciTech Connect

The H-D isotopic exchange between H{sub 2} and D{sub 2} and between H{sub 2} (D{sub 2}) and D{sub 2}S (H{sub 2}S) was studied at 80{degree}C in a recycling reactor under a pressure of 2 bar in the presence of a sulfided NiMo/Al{sub 2}O{sub 3} catalyst and by means of gas chromatography. From the H{sub 2}-D{sub 2} exchange an amount of three exchangeable surface hydrogen atoms retained by the catalyst per Mo atom was estimated after sulfiding the catalyst by 10% H{sub 2}S in H{sub 2} at 400{degree}C and sweeping it by helium at 80{degree}C H-D isotope exchange occurred between H{sub 2}(D{sub 2}) and D{sub 2}S(H{sub 2}S). As expected under the reaction conditions, H{sub 2}S(D{sub 2}S) did not produced H{sub 2}(D{sub 2}). The isotope exchange between H{sub 2} and D{sub 2} was about six times faster than the exchange between H{sub 2}(D{sub 2}) and D{sub 2}S(H{sub 2}S). However, it was shown that H{sub 2}S competed with H{sub 2} for adsorption: H{sub 2}S inhibited the exchange between H{sub 2} and D{sub 2}. It is proposed that H{sub 2}(D{sub 2}) and H{sub 2}S(D{sub 2}S) dissociate heterolytically on the same sites, involving both a sulfur vacancy and a sulfur atom. Furthermore, it is suggested that the isotope exchange could occur by dissociation of both reactants on one single center provided that this center possesses at least two coordinative unsaturations. 47 refs., 8 figs., 2 tabs.

Thomas, C.; Vivier, L.; Lemberton, J.L. [Universite de Poitiers (France)] [and others

1997-04-01

409

Borax and octabor treatment of stored swine manure to reduce sulfate reducing bacteria and hydrogen sulfide emissions  

Technology Transfer Automated Retrieval System (TEKTRAN)

Odorous gas emissions from stored swine manure are becoming serious environmental and health issues as the livestock industry becomes more specialized, concentrated, and industrialized. These nuisance gasses include hydrogen sulfide (H2S), ammonia, and methane, which are produced as a result of ana...

410

AMMONIA AND HYDROGEN SULFIDE FLUX AND DRY DEPOSITION VELOCITY ESTIMATES USING VERTICAL GRADIENT METHOD AT A COMMERCIAL BEEF CATTLE FEEDLOT  

Technology Transfer Automated Retrieval System (TEKTRAN)

Ammonia and hydrogen sulfide flux and dry deposition velocity were estimated using micrometeorological vertical gradient flux method at a commercial cattle feedyard of approximately 50,000 head of beef cattle and average 14.4 m2/head (150 ft2/head) stocking density. During summertime, NH3-N emission...

411

Changes in arterial hydrogen sulfide (H 2S) content during septic shock and endotoxin shock in rats  

Microsoft Academic Search

Objectives: To explore the changes of hydrogen sulfide (H2S) in vascular tissues of rats with septic shock and endotoxin shock and its possible pathophysiological implication. Methods: Rat models of septic shock induced by cecal ligation and puncture and of endotoxic shock induced by injection of endotoxin were used in this study. The authors measured hymodynamic variations, metabolic data, H2S and

Yan Hui; Junbao Du; Chaoshu Tang; Geng Bin; Hongfeng Jiang

2003-01-01

412

[The importance of dermatological studies within sanitary measure system at industry processing natural gas with high hydrogen sulfide content].  

PubMed

Enterprises processing natural gas with high hydrogen sulfide content appear to be alarming for prophylaxis of occupational skin diseases. Dermatologic symptoms and functional state of skin demonstrate direct and mediated unfavorable influence of industrial factors on workers and lead to prophylactic and sanative measures. PMID:11019546

Miroshnikova, G I; Davydova, L D

2000-01-01

413

Industrial Sources Influence Air Concentrations of Hydrogen Sulfide and Sulfur Dioxide in Rural Areas of Western Canada  

Microsoft Academic Search

A survey of monthly average concentrations of sulfur dioxide (SO2) and hydrogen sulfide (H2S) at rural locations in western Canada (provinces of Alberta, British Columbia, and Saskatchewan) was conducted in 2001– 2002, as part of an epidemiological study of the effects of oil and gas industry emissions on the health of cattle. Repeated measurements were obtained at some months and

Igor Burstyn; Ambikaipakan Senthilselvan; Hyang-Mi Kim; Nicola M. Cherry; Elise Pietroniro; Cheryl Waldner; George Hidy; Paul Lioy; Herbert McKee; David Mobley; Yasuko Yoshida; Azusa Ito; Masashi Murakami; Takayuki Murakami; Hideharu Fujimoto; Kikuo Takeda; Shigeru Suzuki; Masahiro Hori; Huan Liu; Kebin He; Qidong Wang; Hong Huo; James Lents; Nicole Davis; Nick Nikkila; Changhong Chen; Mauricio Osses; Chunyu He; Thomas Hilber; Michalis Agraniotis; Panagiotis Grammelis; Emmanuel Kakaras; Thomas Glorius; Uwe Becker; Willy Derichs; Hans-Peter Schiffer; Martin Jong; Lucia Torri; Glynis Lough; Charles Christensen; James Schauer; James Tortorelli; Erin Mani; Douglas Lawson; Nigel Clark; Peter Gabele; Aki Virkkula; Timo; Risto Hillamo; Tarja Yli-Tuomi; Anne Hirsikko; Ismo Koponen; Nicholas Doll; John Reisel; Aro´n Jazcilevich; Alejandro Garcý´a-Fragoso; Agustý´n Reynoso; Michel Grutter; Ulises Diego-Ayala; Delbert Eatough; Nolan Mangelson; Richard Anderson; Donald Martello; Natalie Pekney; Cliff Davidson; William Modey

2007-01-01

414

Distribution and Function of the Hydrogen Sulfide–Sensitive TRPA1 Ion Channel in Rat Urinary Bladder  

Microsoft Academic Search

ObjectivesTo investigate the distribution of the transient receptor potential (TRP) A1 ion channel in the rat urinary bladder, and to study the effects of hydrogen sulfide (H2S) and known TRPA1 activators on micturition in conscious rats and on heterologously expressed ion channels.

Tomi Streng; Helena E. Axelsson; Petter Hedlund; David A. Andersson; Sven-Eric Jordt; Stuart Bevan; Karl-Erik Andersson; Edward D. Högestätt; Peter M. Zygmunt

2008-01-01

415

Clean-up of low-concentration ventilation discharge from viscose manufacturing plants from carbon disulfide and hydrogen sulfide  

Microsoft Academic Search

Three basic trends are described in cleaning up low-concentration discharges from carbon disulfide in order to protect the atmosphere from industrial contaminants: using activated carbon fabrics, alkalized activated carbons, or absorptive solution containing chemosorbents or catalysts. In the case where the third method is used, hydrogen sulfide is removed by use of the same absorptive solution which from carbon disulfide

I. G. Shimko; S. K. Chinennaya; V. P. Katushkin; V. S. Minster; L. I. Pechalin; L. A. Rybakov; R. I. Zakirova

1984-01-01

416

A model for the corrosion of steel subjected to synthetic produced water containing sulfate, chloride and hydrogen sulfide  

Microsoft Academic Search

A model was developed for the prediction of corrosion rates associated with steel subjected to synthetic produced water. The corrosive species included in the model, identified through water analysis conducted in the field, are sulfate, chloride and hydrogen sulfide. The effect on corrosion of these species was examined through polarization experimentation using a three electrode glass corrosion cell and potentiostat.

Peter Smith; Sudipta Roy; David Swailes; Stephen Maxwell; David Page; John Lawson

2011-01-01

417

Cracking resistance of high-strength steel in inhibited hydrogen-sulfide solutions with different values of pH  

SciTech Connect

The authors assess the protective properties of three inhibitors based on pyridines and aminonitriles in the corrosion protection of natural gas field production equipment against the effects of hydrogen sulfide solutions of different pH. The tests were made on 65G steel wire. The resistance of the steel to corrosion and crack propagation as well as hydrogen embrittlement is given for each of the inhibitors.

Lubenskii, A.P.; Vyakhirev, Yu.R.; Gutman, E.M.

1987-11-01

418

Increased growth and germination success in plants following hydrogen sulfide administration.  

PubMed

This study presents a novel way of enhancing plant growth through the use of a non-petroleum based product. We report here that exposing either roots or seeds of multicellular plants to extremely low concentrations of dissolved hydrogen sulfide at any stage of life causes statistically significant increases in biomass including higher fruit yield. Individual cells in treated plants were smaller (~13%) than those of controls. Germination success and seedling size increased in, bean, corn, wheat, and pea seeds while time to germination decreases. These findings indicated an important role of H2S as a signaling molecule that can increase the growth rate of all species yet tested. The increased crop yields reported here has the potential to effect the world's agricultural output. PMID:23614010

Dooley, Frederick D; Nair, Suven P; Ward, Peter D

2013-04-17

419

Thioredoxin and dihydrolipoic acid are required for 3-mercaptopyruvate sulfurtransferase to produce hydrogen sulfide.  

PubMed

H2S (hydrogen sulfide) has recently been recognized as a signalling molecule as well as a cytoprotectant. We recently demonstrated that 3MST (3-mercaptopyruvate sulfurtransferase) produces H2S from 3MP (3-mercaptopyruvate). Although a reducing substance is required for an intermediate persulfide at the active site of 3MST to release H2S, the substance has not been identified. In the present study we show that Trx (thioredoxin) and DHLA (dihydrolipoic acid) associate with 3MST to release H2S. Other reducing substances, such as NADPH, NADH, GSH, cysteine and CoA, did not have any effect on the reaction. We also show that 3MST produces H2S from thiosulfate. The present study provides a new insight into a mechanism for the production of H2S by 3MST. PMID:21732914

Mikami, Yoshinori; Shibuya, Norihiro; Kimura, Yuka; Nagahara, Noriyuki; Ogasawara, Yuki; Kimura, Hideo

2011-11-01

420

Adsorption of hydrogen sulfide onto activated carbon fibers: effect of pore structure and surface chemistry.  

PubMed

To understand the nature of H2S adsorption onto carbon surfaces under dry and anoxic conditions, the effects of carbon pore structure and surface chemistry were studied using activated carbon fibers (ACFs) with different pore structures and surface areas. Surface pretreatments, including oxidation and heattreatment, were conducted before adsorption/desorption tests in a fixed-bed reactor. Raw ACFs with higher surface area showed greater adsorption and retention of sulfur, and heat treatment further enhanced adsorption and retention of sulfur. The retained amount of hydrogen sulfide correlated well with the amount of basic functional groups on the carbon surface, while the desorbed amount reflected the effect of pore structure. Temperature-programmed desorption (TPD) and thermal gravimetric analysis (TGA) showed that the retained sulfurous compounds were strongly bonded to the carbon surface. In addition, surface chemistry of the sorbent might determine the predominant form of adsorbate on the surface. PMID:16475362

Feng, Wenguo; Kwon, Seokjoon; Borguet, Eric; Vidic, Radisav

2005-12-15

421

Adsorption of hydrogen sulfide onto activated carbon fibers: effect of pore structure and surface chemistry  

SciTech Connect

To understand the nature of H{sub 2}S adsorption onto carbon surfaces under dry and anoxic conditions, the effects of carbon pore structure and surface chemistry were studied using activated carbon fibers (ACFs) with different pore structures and surface areas. Surface pretreatments, including oxidation and heat treatment, were conducted before adsorption/desorption tests in a fixed-bed reactor. Raw ACFs with higher surface area showed greater adsorption and retention of sulfur, and heat treatment further enhanced adsorption and retention of sulfur. The retained amount of hydrogen sulfide correlated well with the amount of basic functional groups on the carbon surface, while the desorbed amount reflected the effect of pore structure. Temperature-programmed desorption (TPD) and thermal gravimetric analysis (TGA) showed that the retained sulfurous compounds were strongly bonded to the carbon surface. In addition, surface chemistry of the sorbent might determine the predominant form of adsorbate on the surface. 38 refs., 7 figs., 3 tabs.

Wenguo Feng; Seokjoon Kwon; Eric Borguet; Radisav Vidic [University of Pittsburgh, Pittsburgh, PA (United States). Department of Civil and Environmental Engineering

2005-12-15

422

The reactions of mercurated pyrimidine nucleotides with thiols and with hydrogen sulfide.  

PubMed Central

In the presence of thiols, 5-mercuripyrimidine nucleotides are quantitatively converted to 5-thiomercuri derivatives, but these compounds are unstable and decompose at a rate dependent on the nature of the thiol. The decomposition involves three different reactions and proceeds via a symmetrical mercury derivative of the nucleotide. The end product is the unmodified nucleotide. Similar reactions occur in the presence of hydrogen sulfide. Since mercurated nucleoside triphosphates are substrates for RNA- and DNA polymerase only in the form of thiomercuri derivatives, this implies that when DNA is replicated or transcribed in vitro with a mercurated substrate, the latter is rapidly demercurated to the unmodified substrate which is incorporated as well. Hence the product of the in vitro synthesis can only be partially mercurated in any one pyrimidine. Also, formation of cross-links in the resulting polymer is possible.

Van Broeckhoven, C; De Wachter, R

1978-01-01

423

How to pressurize autoclaves for corrosion testing under carbon dioxide and hydrogen sulfide pressure  

SciTech Connect

All the methods presently used for pressurizing autoclaves have advantages and disadvantages. Pressurizing with pure gases is undoubtedly the surest method, since it is insensitive to the autoclave filling rate, and the influence of temperature stability readily can be controlled. The only limitation is the impossibility of accurately reproducing very low hydrogen sulfide (H{sub 2}S) partial pressures (<30 mbar) at high temperatures (>150 C). Conventional pressurizing with gas mixtures is not at all practical, since it demands either excessively large autoclaves or the bubbling of prohibitive volumes of gas. To overcome these fundamental difficulties, alternative methods are proposed, such as high-temperature bubbling using a cooled reflux condenser or presaturation of the autoclave at 60 C at a fraction of the test pressure, enabling the latter to be attained during subsequent heating by the natural increase in pressure with temperature.

Crolet, J.L.; Bonis, M.R.

2000-02-01

424

Hydrogen sulfide-releasing aspirin inhibits the growth of leukemic Jurkat cells and modulates ?-catenin expression.  

PubMed

Hydrogen sulfide-releasing aspirin (HS-ASA) is a novel compound with potential against cancer. It inhibited the growth of Jurkat T-leukemia cells with an IC50 of 1.9±0.2?M whereas that of ASA was >5000?M. It dose-dependently inhibited proliferation and induced apoptosis in these cells, causing a G0/G1 cell cycle arrest. HS-ASA down-regulated ?-catenin protein levels and reduced mRNA and protein expression of ?-catenin/TCF downstream target genes cyclinD1 and c-myc. Aspirin up to 5mM had no effect on ?-catenin expression. HS-ASA also increased caspase-3 protein levels and dose-dependently increased its activity. These effects were substantially blocked by z-VAD-fmk, a pan-caspase inhibitor. PMID:23896061

Chattopadhyay, Mitali; Nath, Niharika; Kodela, Ravinder; Sobocki, Tomasz; Metkar, Shalaka; Gan, Zong Yuan; Kashfi, Khosrow

2013-07-26

425

Kinetics of hydrolysis and oxidation of carbon disulfide by hydrogen peroxide in alkaline medium and application to carbonyl sulfide  

SciTech Connect

Kinetic studies of the oxidation of carbon disulfide by hydrogen peroxide in alkaline medium were made spectrophotometrically. The reaction of CS/sub 2/ with OH/sup -/ ion was found to be rate controlling and proceeded by the formation of a dithiocarbonate complex. The major reaction product was sulfate with sulfur occurring as colloidal suspensions only at pH values less than 8. The formation of sulfate increased exponentially with time and was also found to be dependent on the rate of hydrolysis of CS/sub 2/. In addition, the production of sulfate showed large induction periods, suggesting either a complex mechanism or formation by secondary reactions. The results obtained for carbon disulfide were extended to carbonyl sulfide (OCS) oxidation in alkaline solutions. The removal of OCS (acid gas) from mixtures of gases by alkaline liquid absorbents (e.g. NaOH) and oxidation of subsequent solutions to sulfate is an important industrial practice. 42 references, 14 figures, 2 tables.

Adewuyi, Y.G.; Carmichael, G.R.

1987-02-01

426

Hydrogenation reactions of ethylene on neutral vanadium sulfide clusters: experimental and theoretical studies.  

PubMed

The reactions of C(2)H(4) with H(2) on neutral vanadium sulfide clusters in a fast flow reactor are investigated by time-of-flight mass spectrometry employing 118 nm (10.5 eV) single photon ionization. The experimental products of these reactions are V(m)S(n)C(2)H(x) (m=1, n=1-3; m=2, n=1-5, and x=4-6). Observation of these products indicates that these V(m)S(n) clusters have high catalytic activity for hydrogenation reactions of C(2)H(4). Density functional theory calculations at the BPW91/TZVP level are carried out to explore the geometric and electronic structures of the V(m)S(n) clusters and to determine reaction intermediates and transition states, as well as reaction mechanisms. All reactions are estimated as overall barrierless or with only a small barrier (0.1 eV), and are thermodynamically favorable processes at room temperature. The ethylene molecule is predicted to connect with active V atoms through its ?-orbital or form a ?-bond with active V atoms of catalytic V(m)S(n) clusters. The S atoms bonding with active V atoms play an important role in the dissociation of the H(2) molecule; H atoms transfer to the C(2)H(4) (one after another) following breaking of the H-H bond. A catalytic cycle for C(2)H(4) hydrogenation reactions on a vanadium sulfide catalyst surface is suggested based on our experimental and theoretical investigations. PMID:21838236

Yin, Shi; Xie, Yan; Bernstein, Elliot R

2011-08-29

427

Hydrogen Sulfide in the RVLM and PVN has No Effect on Cardiovascular Regulation  

PubMed Central

Hydrogen sulfide (H2S) is now recognized as an important signaling molecule and has been shown to have vasodilator and cardio-protectant effects. More recently it has been suggested that H2S may also act within the brain to reduce blood pressure (BP). In the present study we have demonstrated the presence of the H2S-producing enzyme, cystathionine-?-synthase (CBS) in the rostral ventrolateral medulla (RVLM), and the hypothalamic paraventricular nucleus (PVN), brain regions with key cardiovascular regulatory functions. The cardiovascular role of H2S was investigated by determining the BP, heart rate (HR), and lumbar sympathetic nerve activity (LSNA) responses elicited by a H2S donor sodium hydrogen sulfide (NaHS) or inhibitors of CBS, microinjected into the RVLM and PVN. In anesthetized Wistar Kyoto rats bilateral microinjections of NaHS (0.2–2000?pmol/side) into the RVLM did not significantly affect BP, HR, or LSNA, compared to vehicle. Similarly, when the CBS inhibitors, amino-oxyacetate (AOA; 0.1–1.0?nmol/side) or hydroxylamine (HA; 0.2–2.0?nmol/side), were administered into the RVLM, there were no significant effects on the cardiovascular variables compared to vehicle. Microinjections into the PVN of NaHS, HA, and AOA had no consistent significant effects on BP, HR, or LSNA compared to vehicle. We also investigated the cardiovascular responses to NaHS microinjected into the RVLM and PVN in spontaneously hypertensive rats. Again, there were no significant effects on BP, HR, and LSNA. Together, these results suggest that H2S in the RVLM and PVN does not have a major role in cardiovascular regulation.

Streeter, Eloise; Al-Magableh, Mohammad; Hart, Joanne Louise; Badoer, Emilio

2011-01-01

428

Hydrogen sulfide in the mouse ductus arteriosus: a naturally occurring relaxant with potential EDHF function.  

PubMed

We have previously reported that bradykinin relaxes the fetal ductus arteriosus via endothelium-derived hyperpolarizing factor (EDHF) when other naturally occurring relaxants (prostaglandin E2, nitric oxide, and carbon monoxide) are suppressed, but the identity of the agent could not be ascertained. Here, we have examined in the mouse whether hydrogen sulfide (H2S) is a relaxant of the ductus and, if so, whether it may also function as an EDHF. We found in the vessel transcripts for the H2S synthetic enzymes, cystathionine-?-lyase (CSE) and cystathionine-?-synthase (CBS), and the presence of these enzymes was confirmed by immunofluorescence microscopy. CSE and CBS were distributed across the vessel wall with the former prevailing in the intimal layer. Both enzymes occurred within the endoplasmic reticulum of endothelial and muscle cells, whereas only CSE was located also in the plasma membrane. The isolated ductus contracted to inhibitors of CSE (d,l-propargylglycine, PPG) and CBS (amino-oxyacetic acid), and PPG contraction was attenuated by removal of the endothelium. EDHF-mediated bradykinin relaxation was curtailed by both PPG and amino-oxyacetic acid, whereas the relaxation to sodium nitroprusside was not affected by either treatment. The H2S donor sodium hydrogen sulfide (NaHS) was also a potent, concentration-dependent relaxant. We conclude that the ductus is endowed with a H2S system exerting a tonic relaxation. In addition, H2S, possibly via an overriding CSE source, qualifies as an EDHF. These findings introduce a novel vasoregulatory mechanism into the ductus, with implications for antenatal patency of the vessel and its transitional adjustments at birth. PMID:23376828

Baragatti, Barbara; Ciofini, Enrica; Sodini, Daria; Luin, Stefano; Scebba, Francesca; Coceani, Flavio

2013-02-01

429

Hydrogen sulfide-induced dual vascular effect involves arachidonic acid cascade in rat mesenteric arterial bed.  

PubMed

Hydrogen sulfide (H(2)S), a novel gaseous transmitter, is considered a physiological regulator of vascular homeostasis. Recent evidence suggests H(2)S as an endothelium-hyperpolarizing factor (EDHF) candidate. To address this issue, we evaluated the vascular effect of sodium hydrogen sulfide (NaHS), an H(2)S donor, on the rat mesenteric arterial bed. NaHS concentration-response curve was performed on preconstricted mesenteric arterial bed. To assess the contribution of EDHF, we performed a pharmacologic dissection using indomethacin, N(G)-nitro-l-arginine methyl ester (l-NAME), or apamin and charybdotoxin as cyclooxygenase, nitric-oxide synthase, and calcium-dependent potassium channel inhibitors, respectively. In another set of experiments, we used 4-(4-octadecylphenyl)-4-oxobutenoic acid, baicalein, or proadifen as phospholipase A(2) (PLA(2)), lipoxygenase, and cytochrome P450 inhibitors, respectively. Finally, an immunofluorescence study was performed to support the involvement of PLA(2) in mesenteric artery challenged by NaHS. NaHS promoted a dual vascular effect (i.e., vasoconstriction and vasodilation). l-NAME or baicalein administration affected neither NaHS-mediated vasodilation nor vasoconstriction, whereas apamin and charybdotoxin significantly inhibited NaHS-induced relaxation. Pretreatment with PLA(2) inhibitor abolished both the contracting and the relaxant effect, whereas P450 cytochrome blocker significantly reduced NaHS-mediated relaxation. The immunofluorescence study showed that NaHS caused a migration of cytosolic PLA(2) close to the nucleus, which implicates activation of this enzyme. Our data indicate that H(2)S could activate PLA(2), which in turn releases arachidonic acid leading, initially, to vasoconstriction followed by vasodilation mediated by cytochrome P450-derived metabolites. Because EDHF has been presumed to be a cytochrome P450 derivative of the arachidonic acid, our results suggest that H(2)S acts through EHDF release. PMID:21228064

d'Emmanuele di Villa Bianca, Roberta; Sorrentino, Rosalinda; Coletta, Ciro; Mitidieri, Emma; Rossi, Antonietta; Vellecco, Valentina; Pinto, Aldo; Cirino, Giuseppe; Sorrentino, Raffaella

2011-01-12

430

Removal of hydrogen sulfide from hot fuel gas using an electrochemical membrane system  

NASA Astrophysics Data System (ADS)

Sulfur is a natural contaminant in nearly all fossil fuel supplies. When a fuel stream is gasified or reformed, the sulfur manifests itself in the form of hydrogen sulfide, H2S. Extraordinary effort is put forth to remove H2S to at least ppm levels before the fuel can be used for power generation. To compete with current methods, an electrochemical membrane system (EMS) is now being studied to remove H2S in one step at high temperature. This process offers continuous H2S removal at an estimated operating cost of $0.32/kg H2S removed and a capital cost that is roughly half that of a Claus plant with tail-gas clean-up. Other advantages are the considerable savings in energy and space compared to current methods. A bench scale set-up was constructed to test the cell performance at 600-700°C and 1 atm. The typical fuel stream inlet proportions were 34% CO, 22% CO2, 35% H2, 8% H2O, and 450-2000 ppm H2S. The fundamental transport restrictions for sulfur species in an electrochemical cell were examined. Temperature and membrane thickness were varied to examine how these parameters affect the maximum flux of H 2S removal. It was found that higher temperature allows more sulfide species to enter the electrolyte, thus increasing the sulfide flux across the membrane and raising the maximum flux of H2S removal. Also, membrane thickness was found to be a critical parameter in cell design. A thinner membrane decreases the distance that sulfide ions must travel to be oxidized at the anode. These results identify sulfide diffusion across the membrane as the rate-limiting step in H2S removal. The maximum H2S removal flux of 1.1 x 10-6 gmol H2S min-1 cm-2 (or 3.5 mA cm-2) was obtained at 650°C, with a membrane that was 0.9 mm thick, 36% porous, and had an estimated tortuosity of 3.6. Another focus of this thesis was to examine the stability of cathode materials in full cell trials. A major hurdle that remains in process scale-up is cathode selection, as the lifetime of the cell will depend heavily on the lifetime of the cathode material, which is exposed to very sour gas. Materials that showed success in the past (i.e cobalt sulfides and Y0.9Ca 0.1FeO3) were examined but were seen to have limitations in operating environment and temperature. Therefore, other novel metal oxide compounds were studied to find possible candidates for full cell trials. Gd2TiMoO7 and La0.7Sr0.3VO 3 were the compounds that retained their structure best even when exposed to high H2S, CO2, and H2O concentrations. They also showed no sign of melting at operating temperatures. But Gd 2TiMoO7 was seen to have better stability with electrolyte present, whereas La0.7Sr0.3VO3 was seen to have better stability in the pure sour gas stream without electrolyte present. A layered electrode that could help preserve a stable environment for each of these compounds should be explored in future research.

Burke, Adrian Alan

431

Vapor-liquid equilibria for the systems difluoromethane + hydrogen fluoride, dichlorodifluoromethane + hydrogen fluoride, and chlorine + hydrogen fluoride  

Microsoft Academic Search

Isothermal vapor-liquid equilibria for difluoromethane + hydrogen fluoride, dichlorodifluoromethane + hydrogen fluoride, and chlorine + hydrogen fluoride have been measured. The experimental data for the binary systems are correlated with the NRTL equation with the vapor-phase association model for the mixtures containing hydrogen fluoride, and the relevant parameters are presented. The binary system difluoromethane + hydrogen fluoride forms a homogeneous

Yun Whan Kang

1998-01-01

432

Hydrogenation of coal liquid utilizing a metal carbonyl catalyst  

DOEpatents

Coal liquid having a dissolved transition metal, catalyst as a carbonyl complex such as Co.sub.2 (CO.sub.8) is hydrogenated with hydrogen gas or a hydrogen donor. A dissociating solvent contacts the coal liquid during hydrogenation to form an immiscible liquid mixture at a high carbon monoxide pressure. The dissociating solvent, e.g. ethylene glycol, is of moderate coordinating ability, while sufficiently polar to solvate the transition metal as a complex cation along with a transition metal, carbonyl anion in solution at a decreased carbon monoxide pressure. The carbon monoxide pressure is reduced and the liquids are separated to recover the hydrogenated coal liquid as product. The dissociating solvent with the catalyst in ionized form is recycled to the hydrogenation step at the elevated carbon monoxide pressure for reforming the catalyst complex within fresh coal liquid.

Feder, Harold M. (Hinsdale, IL); Rathke, Jerome W. (Bolingbrook, IL)

1979-01-01

433

Theoretical analysis for the heterogeneous decomposition of hydrogen sulfide to hydrogen on an iron-metallic plate in a laminar stagnation-point flow  

NASA Astrophysics Data System (ADS)

In this work, we have theoretically analyzed the conversion process of hydrogen sulfide, H2S, to atomic hydrogen, H0, in a planar stagnation-point flow over an iron-metallic surface. We assume that a binary mixture of hydrogen sulfide and methane composes the laminar stagnation flow. In order to characterize this complex phenomenon with very specific chemical activities on the surface of the metallic plate, we propose a heterogeneous reaction scheme based on four reactions: two electrochemical, one adsorption and an additional exothermic reaction needed to complete the direct conversion of hydrogen sulfide to hydrogen on the surface of the iron. The nondimensional governing equations, which include the mass species and momentum conservation of the mixture and the molecular diffusion of hydrogen into the iron plate, are numerically solved by conventional finite-difference methods. The numerical results show the critical conditions of the H2S decomposition as functions of the involved nondimensional parameters of the present model. In particular, we show parametrically the influence that has the initial concentration of H2S on the surface coverage of the chemical products HS- H+ and H0 derived from the chemical and electrochemical reactions.

Martínez, J. C.; Méndez, F.; Treviño, C.

2006-12-01

434

Effective Hydrogen Generation from the Hydrogen Sulfide Solution by using Stratified Type Photocatalyst  

SciTech Connect

Stratified type photocatalyst with the extremely higher photocatalytic activities can be synthesized by using the chemical reaction between the Na{sub 2}S solution and Cd(OH){sub 2} precursors. This type of photocatalyst has the specific morphology which constructed by the nano-sized and capsule like formed structure, and the metal concentration was gradually changed in its wall. The 'charge gradient' was formed at the metal sulfide and oxide/hydroxide junction in the wall, which favored for the separation of the photo excited electron-hole pair. Consequently, stratified type photocatalyst shows the high catalytic activity than the usual nano CdS particles. By the addition of sulfur compound into the bio reactor contained the sulfur reducing bacteria, the H{sub 2}S gas concentration can increased to about 1000 times enlarge than the usual condition. Therefore, we can conclude that the enhancement of the H{sub 2}S gas evolved from the bio reactor was successfully achievement, and we don't need to afraid the shortage risk of H{sub 2}S supply. These H{sub 2}S gas concentration can enlarged to 80% by using A type zeorite. Especially, Ca-A type zeorite is considered as the suitable material.

Takahashi, H.; Yokoyama, S.; Baba, Y.; Hayashi, T.; Tohji, K. [Graduate School of Environmental Studies, Tohoku University 6-6-20 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi-ken 980-8579 (Japan)

2008-02-25

435

Vapor-liquid equilibria for the systems difluoromethane + hydrogen fluoride, dichlorodifluoromethane + hydrogen fluoride, and chlorine + hydrogen fluoride  

SciTech Connect

Isothermal vapor-liquid equilibria for difluoromethane + hydrogen fluoride, dichlorodifluoromethane + hydrogen fluoride, and chlorine + hydrogen fluoride have been measured. The experimental data for the binary systems are correlated with the NRTL equation with the vapor-phase association model for the mixtures containing hydrogen fluoride, and the relevant parameters are presented. The binary system difluoromethane + hydrogen fluoride forms a homogeneous liquid phase, and the others form minimum boiling heterogeneous azeotropes at the experimental conditions.

Kang, Y.W. [KIST, Seoul (Korea, Republic of). Div. of Environmental and CFC Technology

1998-01-01

436

Adsorption and Reaction of Hydrogen Sulfide on Thin-film Cerium Oxide  

SciTech Connect

The adsorption and reaction of hydrogen sulfide, H{sub 2}S, have been studied on cerium oxide thin films that were vapor deposited on Ru(0 0 0 1). The behavior of the H{sub 2}S was examined as a function of Ce oxidation state. H{sub 2}S weakly chemisorbs on fully oxidized CeO{sub 2} desorbing near 155 K. Hydrogen from the H{sub 2}S reacts with the surface O to desorb as water between 200 K and 450 K. When ca. 20% of the Ce{sup 4+} is reduced to Ce{sup 3+} more H{sub 2}S dissociates to -OH and -SH and water is produced near 580 K. When the ceria is ca. 70% reduced, water formation is suppressed and H{sub 2} desorbs near 580 K. S 2p photoelectron spectroscopy indicates the decomposition of H{sub 2}S into -SH and then -S as the sample is annealed from 100 K to 600 K. O 1s photoemission indicated the presence of H{sub 2}O and -OH.

Mullins, David R [ORNL; McDonald, Tom S [ORNL

2007-01-01

437

Factors affecting activated carbon-based catalysts for selective hydrogen sulfide oxidation  

SciTech Connect

The primary product of coal gasification processes is synthesis gas (syngas), a mixture of CO, H2, CO2, H2O and a number of minor components. Among the most significant minor components in syngas is hydrogen sulfide (H2S). In addition to its adverse environmental impact, H2S poisons the catalysts and hydrogen purification membranes, and causes severe corrosion in gas turbines. Technologies that can remove H2S from syngas and related process streams are, therefore, of considerable practical interest. To meet this need, we work towards understanding the mechanism by which prospective H2S catalysts perform in simulated fuel gas conditions. Specifically, we show that for low-temperature gas clean-up (~1408C) using activated carbon fibers and water plays a significant role in H2S binding and helps to prolong the lifetime of the material. Basic surface functional groups were found to be imperative for significant conversion of H2S to daughter compounds, whereas metal oxides (La and Ce) did little to enhance this catalysis. We show that although thermal regeneration of the material is possible, the regenerated material has a substantially lower catalytic and sorption capacity.

Li, Huixing; Monnell, J.D.; Alvin, M.A.; Vidic, R.D.

2008-09-01

438

Kinetics and mechanisms of iron sulfide reductions in hydrogen and in carbon monoxide  

USGS Publications Warehouse

The reduction of iron sulfides by hydrogen and by carbon monoxide has been studied using plug flow and thermogravimetric methods. The reactions were studied in the 523-723??K temperature range and were found to be first-order processes. Plug flow studies were used to correlate reaction rates between pyrite and the gases as a function of the surface area of the pyrite. The rate of H2S formation increases with the surface area of the pyrite sample. The results of thermogravimetric experiments indicate that the reactions consist of several steps. Rate constants for the pyrite reduction by H2 and by CO were obtained. The activation energies increased with degree of reduction. Values of Ea were 113.2 (step I) and 122.5 kJ/mole (step II) for pyrite reduction with CO and 99.4 (step I), 122.4 (step II), 125.2 (step III), and 142.6 kJ/mole (step IV) for pyrite reduction with hydrogen. ?? 1987.

Wiltowski, T.; Hinckley, C. C.; Smith, G. V.; Nishizawa, T.; Saporoschenko, M.; Shiley, R. H.; Webster, J. R.

1987-01-01

439

Vasoactivity of hydrogen sulfide in normoxic and anoxic turtles (Trachemys scripta).  

PubMed

Systemic vascular resistance (R(sys)) of freshwater turtles increases substantially during anoxia, but the underlying mechanisms are not fully understood. We investigated whether hydrogen sulfide (H(2)S), an endogenously produced metabolite believed to be an O(2) sensor/transducer of vasomotor tone, contributes to the increased R(sys) of anoxic red-eared slider turtles (Trachemys scripta). Vascular infusion of the H(2)S donor NaHS in anesthetized turtles at 21 degrees C and fully recovered normoxic turtles at 5 degrees C and 21 degrees C revealed H(2)S to be a potent vasoconstrictor of the systemic circulation. Likewise, wire myography of isolated turtle mesenteric and pulmonary arteries demonstrated H(2)S to mediate an anoxia-induced constriction. Intriguingly, however, NaHS did not exert vasoconstrictory effects during anoxia (6 h at 21 degrees C; 14 days at 5 degrees C) when plasma H(2)S concentration, estimated from the colorimetric measurement of plasma acid-labile sulfide concentration, likely increased by approximately 3- and 4-fold during anoxia at 21 degrees C, and 5 degrees C, respectively. Yet, blockade of endogenous H(2)S production by DL-propargylglycine or hydroxylamine (0.44 mmol/kg) partially reversed the decreased systemic conductance (G(sys)) exhibited by 5 degrees C anoxic turtles. These findings suggest that the signal transduction pathway of H(2)S-mediated vasoactivity is either maximally activated in the systemic circulation of anoxic turtles and/or that it is oxygen dependent. PMID:20164201

Stecyk, Jonathan A W; Skovgaard, Nini; Nilsson, Göran E; Wang, Tobias

2010-02-17

440

Intramitochondrial hydrogen sulfide production by 3-mercaptopyruvate sulfurtransferase maintains mitochondrial electron flow and supports cellular bioenergetics.  

PubMed

It is well established that exposure of mammalian cells to hydrogen sulfide (H(2)S) suppresses mitochondrial function by inhibiting cytochrome-c oxidase (CcOX; complex IV). However, recent experimental data show that administration of H(2)S to mammalian cells can serve as an electron donor and inorganic source of energy. The aim of our study was to investigate the role of endogenously produced H(2)S in the regulation of mitochondrial electron transport and oxidative phosphorylation in isolated liver mitochondria and in the cultured murine hepatoma cell line Hepa1c1c7. Low concentrations of H(2)S (0.1-1 ?M) elicited a significant increase in mitochondrial function, while higher concentrations of H(2)S (3-30 ?M) were inhibitory. The positive bioenergetic effect of H(2)S required a basal activity of the Krebs cycle and was most pronounced at intermediate concentrations of succinate. 3-mercaptopyruvate (3-MP), the substrate of the mitochondrial enzyme 3-mercaptopyruvate sulfurtransferase (3-MST) stimulated mitochondrial H(2)S production and enhanced mitochondrial electron transport and cellular bioenergetics at low concentrations (10-100 nM), while at higher concentrations, it inhibited cellular bioenergetics. SiRNA silencing of 3-MST reduced basal bioenergetic parameters and prevented the stimulating effect of 3-MP on mitochondrial bioenergetics. Silencing of sulfide quinone oxidoreductase (SQR) also reduced basal and 3-MP-stimulated bioenergetic parameters. We conclude that an endogenous intramitochondrial H(2)S-producing pathway, governed by 3-MST, complements and balances the bioenergetic role of Krebs cycle-derived electron donors. This pathway may serve a physiological role in the maintenance of mitochondrial electron transport and cellular bioenergetics. PMID:23104984

Módis, Katalin; Coletta, Ciro; Erdélyi, Katalin; Papapetropoulos, Andreas; Szabo, Csaba

2012-10-26

441

Physiological role of hydrogen sulfide and polysulfide in the central nervous system.  

PubMed

Hydrogen sulfide (H2S) is a well-known toxic gas that has the smell of rotten eggs. This pungent gas was considered as a physiological mediator, after the identification of endogenous sulfides in the mammalian brain. H2S is produced from l-cysteine by enzymes such as cystathionine ?-synthase (CBS), cystathionine ?-lyase (CSE), and 3-mercaptopyruvate sulfurtransferase (3MST) along with cysteine aminotransferase (CAT). We recently identified a fourth pathway, where H2S is produced from d-cysteine by the enzyme d-amino acid oxidase (DAO) along with 3MST. We demonstrated that H2S is a neuromodulator that facilitates hippocampal long-term potentiation (LTP) by enhancing the activity of N-methyl-d-aspartate (NMDA) receptors. It also induces Ca(2+) influx in the astrocytes by activating the transient receptor potential ankyrin-1 (TRPA1) channels. In addition to being a signaling molecule, it also functions as a neuroprotective agent by enhancing the production of glutathione, a major intracellular antioxidant that scavenges the reactive oxygen species (ROS) in the mitochondria. H2S regulates the activity of the enzymes by incorporating the bound sulfane sulfur to cysteine residues. This modification is known as sulfhydration or sulfuration. The neuroprotective ubiquitin E3 ligase, parkin, enhances its neuroprotective activity by this modification. This review is focused on the functional role of H2S as a signaling molecule and as a cytoprotectant in the nervous system. In addition, this review shows the recent findings that indicate that the H2S-derived polysulfides found in the brain activate TRPA1 channels more potently than parental H2S. PMID:24036365

Kimura, Hideo

2013-09-11

442

Novel Composite Hydrogen-Permeable Membranes for Non-Thermal Plasma Reactors for the Decomposition of Hydrogen Sulfide  

SciTech Connect

The goal of this experimental project is to design and fabricate a reactor and membrane test cell to dissociate hydrogen sulfide (H{sub 2}S) in a non-thermal plasma and recover hydrogen (H{sub 2}) through a superpermeable multi-layer membrane. Superpermeability of hydrogen atoms (H) has been reported by some researchers using membranes made of Group V transition metals (niobium, tantalum, vanadium, and their alloys), although it has yet to be confirmed in this study. A pulsed corona discharge (PCD) reactor has been fabricated and used to dissociate H{sub 2}S into hydrogen and sulfur. A nonthermal plasma cannot be produced in pure H{sub 2}S with our reactor geometry, even at discharge voltages of up to 30 kV, because of the high dielectric strength of pure H{sub 2}S ({approx}2.9 times higher than air). Therefore, H{sub 2}S was diluted in another gas with lower breakdown voltage (or dielectric strength). Breakdown voltages of H{sub 2}S in four balance gases (Ar, He, N{sub 2} and H{sub 2}) have been measured at different H{sub 2}S concentrations and pressures. Breakdown voltages are proportional to the partial pressure of H{sub 2}S and the balance gas. H{sub 2}S conversion and the reaction energy efficiency depend on the balance gas and H{sub 2}S inlet concentrations. With increasing H{sub 2}S concentrations, H{sub 2}S conversion initially increases, reaches a maximum, and then decreases. H{sub 2}S conversion in atomic balance gases, such as Ar and He, is more efficient than that in diatomic balance gases, such as N{sub 2} and H{sub 2}. These observations can be explained by the proposed reaction mechanism of H{sub 2}S dissociation in different balance gases. The results show that nonthermal plasmas are effective for dissociating H{sub 2}S into hydrogen and sulfur.

Morris D. Argyle; John F. Ackerman; Suresh Muknahallipatna; Jerry C. Hamann; Stanislaw Legowski; Guibling Zhao; Ji-Jun Zhang; Sanil John

2005-10-01

443

Health Consultation: Air Quality. Hydrogen Sulfide in Ambient Air Near Saufley Field Construction and Demolition Debris Landfill, Bellview, Escambia County, Florida. EPA Facility ID: FLN000409867.  

National Technical Information Service (NTIS)

In this report, the Florida Department of Health (FDOH) reviewed November and December 2006 hydrogen sulfide air monitoring results from four residential properties near the Saufley Field Landfill, in Bellview, Escambia County, Florida. We reviewed these ...

2007-01-01

444

Ultrastructural and morphometric characteristics of nerve cells and myelinated fibers in the cerebral cortex after chronic exposure to natural gas containing hydrogen sulfide in low concentrations.  

PubMed

We studied ultrastructural and morphometric characteristics of nerve cells and myelinated fibers in the cerebral cortex after chronic exposure to natural gas containing hydrogen sulfide in low concentrations. Radioisotope assay revealed activation of protein synthesis in nerve cells after chronic exposure to natural hydrogen sulfide-containing gas in low concentrations (10 mg/m(3)by H2S) for 2 weeks. After 1 month the ultrastructure of myelinated fibers was characterized by sectorial loosening and demyelination. PMID:12533774

Solnyshkova, T G; Shakhlamov, V A

2002-10-01

445

Solubility of hydrogen sulfide in pure water and in NaCl solutions, from 20 to 320°C and at saturation pressures  

Microsoft Academic Search

The solubility of hydrogen sulfide in pure water and in NaCl solutions has been studied experimentally from 20 to 320°C and at saturation pressures. Hydrogen sulfide solutions in equilibrium with their vapor phase were contained in a pressurized titanium bellows of known total volume. The bellows transmitted inside-vapor pressures via a thermally stable oil (pressure medium) to a high-precision pressure

O. M. Suleimenov; R. E. Krupp

1994-01-01

446

Microbiological removal of hydrogen sulfide from biogas by means of a separate biofilter system: experience with technical operation.  

PubMed

The "BIO-Sulfex" biofilter of ATZ-EVUS removes hydrogen sulfide from biogas in a biological way. Hydrogen sulfide causes massive problems during power generation from biogas in a power plant, e.g. corrosion of engines and heat exchangers, and thus causes frequent and therefore expensive engine oil changes. The BIO-Sulfex module is placed between the digester and the power-plant and warrants a cost-effective, reliable and fully biological desulfurization. In the cleaned gas concentrations of less than 100 ppm can be achieved. Power-plant manufacturers usually demand less than 500 or less than 200 ppm. At present, several plants with biogas flow rates between 20 and 350 m3/h are in operation. PMID:14531443

Schieder, D; Quicker, P; Schneider, R; Winter, H; Prechtl, S; Faulstich, M

2003-01-01

447

A hydrogen sulfide-releasing cyclooxygenase inhibitor markedly accelerates recovery from experimental spinal cord injury.  

PubMed

Spinal cord trauma causes loss of motor function that is in part due to the ensuing inflammatory response. Hydrogen sulfide (H2S) is a potent, endogenous anti-inflammatory and neuroprotective substance that has been explored for use in the design of novel nonsteroidal anti-inflammatory drugs. In the current study, we evaluated the potential beneficial effects of ATB-346 [2-(6-methoxynapthalen- 2-yl)-propionic acid 4-thiocarbamoyl-phenyl ester], an H2S-releasing derivative of naproxen, in a murine model of spinal cord injury (SCI). SCI was induced in mice by spinal cord compression, produced through the application of vascular clips to the dura via a T5 to T8 laminectomy. ATB-346, naproxen (both at 30 ?mol/kg), or vehicle was orally administered to the mice 1 and 6 h after SCI and once daily thereafter for 10 d. Motor function [Basso Mouse Scale (BMS) of locomotion] improved gradually in the mice treated with naproxen. However, those treated with ATB-346 exhibited a significantly more rapid and sustained recovery of motor function, achieving greater than double the increase in locomotion score of the naproxen group by the 10th day of treatment. ATB-346 also significantly reduced the severity of inflammation (proinflammatory cytokines, apoptosis of neural tissue, and nitrosative stress) that characterized the secondary effects of SCI. Again, the effects of ATB-346 were superior to those of naproxen for several parameters. These results showed marked beneficial effects of an H2S-releasing derivative of naproxen in an animal model of SCI, significantly enhancing recovery of motor function, possibly by reducing the secondary inflammation and tissue injury that characterizes this model. The combination of inhibition of cyclooxygenase and delivery of H2S may offer a promising alternative to existing therapies for traumatic injury.-Campolo, M., Esposito, E., Ahmad, A., Di Paola, R., Wallace, J. L., Cuzzocrea, A. Hydrogen sulfide-releasing cyclooxygenase inhibitor markedly accelerates recovery from experimental spinal cord injury. PMID:23901068

Campolo, Michela; Esposito, Emanuela; Ahmad, Akbar; Di Paola, Rosanna; Wallace, John L; Cuzzocrea, Salvatore

2013-07-30

448

Hydrogen sulfide differentially affects the hepatic vasculature in response to phenylephrine and endothelin 1 during endotoxemia.  

PubMed

Despite being protective in many disease states, hydrogen sulfide (H(2)S) contributes to organ injury in sepsis. Like the other gasotransmitters, nitric oxide and carbon monoxide, H(2)S is a modulator of the microcirculation. Because microcirculatory dysfunction is a main cause of organ injury during sepsis, the present study was designed to test the effect of H(2)S on microvascular dysfunction in isolated perfused livers. In most microcirculatory beds, endotoxin activates the endothelium, resulting in hyporesponsiveness to catecholamines and a derangement in blood flow distribution. We demonstrate that H(2)S treatment attenuates the increase in portal pressure during infusion of the ?1 adrenergic agonist, phenylephrine (PE) (P < 0.01). Hydrogen sulfide almost completely negated the increase in portal pressure in livers isolated from endotoxemic rats. Treatment with an inhibitor of endogenous H(2)S, DL-propargylglycine (PAG), reversed lipopolysaccharide-induced hyporesponsiveness to PE. Because hepatic microcirculatory dysfunction is associated with excessive sinusoidal vasoconstriction and not dilation, we investigated whether H(2)S affects endothelin 1 (ET-1)-induced vasoconstriction in isolated livers. Contrary to PE treatment, H(2)S did not affect the increase in portal pressure during infusion of ET-1, nor did it attenuate the hypersensitization of the liver to ET-1 during endotoxemia. Hepatic resistance in control rats was increased by PAG treatment during ET-1 infusion, but this increase was not exacerbated during endotoxemia. We monitored hepatic O(2) consumption to assess the effect of vascular changes on oxygen consumption following ET-1 treatment. Low-dose ET-1 infusion caused an increase in hepatic O(2)consumption, whereas low-dose ET-1 infusion decreased O(2) consumption in endotoxemic livers. Interestingly, whereas we observed no effect of PAG on the vascular response to ET-1 infusion during endotoxemia, PAG treatment did maintain O(2), suggesting a more complex effect of H(2)S inhibition. In summary, the discrepancies between the hepatic response to PE and ET-1 suggest that H(2)S differentially contributes to microcirculatory dysfunction in the systemic and hepatic microcirculations. We propose that this is due to H(2)S exerting a differential vasoactive function on presinusoidal and sinusoidal sites within the liver. Moreover, our findings suggest that H(2)S may contribute to the progression of sepsis by contributing to microvascular failure. PMID:23143058

Norris, Eric J; Larion, Sebastian; Culberson, Catherine R; Clemens, Mark G

2013-02-01

449

Refueling considerations for liquid-hydrogen fueled vehicles  

SciTech Connect

Liquid hydrogen is a possible fuel for transportation applications in the future. Such use of liquid hydrogen will require a refueling station analogous to today's service station for gasoline and diesel fuels. The cryogenic nature of liquid hydrogen and concerns for safety indicate the desirability of a refueling system that is automated as completely as possible and incorporates sufficient redundancy for safe and reliable operation. A refueling system designed on the basis of previous experience with liquid hydrogen transfer systems has been developed, and a preliminary system has been built and tested. A series of tests was conducted to determine the extent of the liquid hydrogen losses during a refueling operation and to determine optimum transfer procedures and conditions.

Stewart, W.F.

1984-01-01

450

Pharmacological activation and genetic manipulation of cystathionine beta-synthase alter circulating levels of homocysteine and hydrogen sulfide in mice  

Microsoft Academic Search

Hydrogen sulfide (H2S) is a recently discovered gasotransmitter found in mammalian tissues and blood. Treatment with H2S donor molecules has shown promising results in preclinical models of inflammatory and cardiovascular diseases. Augmentation of H2S levels thus holds promise as a novel therapeutic approach for treatment of disease in man. Cystathionine ?-synthase (CBS) has been shown to catalyze H2S production in

Kristian K. Jensen; Neil S. Geoghagen; Lan Jin; Tom G. Holt; Qi Luo; Lorraine Malkowitz; Weihua Ni; Shuo Quan; M. Gerard Waters; Aiwu Zhang; Heather H. Zhou; Kang Cheng; Ming-juan Luo

2011-01-01

451

Thermosensitive transfer of antimicrobial resistances and citrate utilization and cotransfer of hydrogen sulfide production from an Escherichia coli isolate  

Microsoft Academic Search

A hydrogen-sulfide producing, citrate-positive strain of Escherichia coli isolated from urinary tract infection was found to be resistant to chloramphenicol (Cm), tetracycline (Tc), streptomycin (Sm), trimethoprim (Tmp), sulfamethoxazole (Smx), and cotrimoxazole (Tmp\\/Smx). The strain contained 7 plasmids of molecular sizes 120, 35, 5.0, 3.2, 3.0, 2.6, and 2.4 megadaltons (Md), as detected by agarose gel electrophoresis of plasmid DNA. Thermosensitive

N. Harnett; L. Mangan; S. Brown; C. Krishnan

1996-01-01

452

The Possible Role of Hydrogen Sulfide as an Endogenous Smooth Muscle Relaxant in Synergy with Nitric Oxide  

Microsoft Academic Search

Hydrogen sulfide (H2S), which is well known as a toxic gas, is produced endogenously in mammalian tissues from L-cysteine mainly by two pyridoxal-5?-phosphate-dependent enzymes, cystathionine ?-synthetase and cystathionine ?-lyase. Recently, we showed that cystathionine ?-synthetase in the brain produces H2S, and that H2S facilitates the induction of hippocampal long-term potentiation by enhancing NMDA receptor activity. Here we show that mRNA

Rumiko Hosoki; Norio Matsuki; Hideo Kimura

1997-01-01

453

Modulating effect of hydrogen sulfide on gamma-aminobutyric acid B receptor in recurrent febrile seizures in rats  

Microsoft Academic Search

Hydrogen sulfide (H2S) is recognized as a new neuromodulator in regulating various brain functions. Some of our recent studies showed that H2S alleviates the hippocampal damage induced by recurrent febrile seizures (FS). In the present study, we used a rat model of recurrent FS and found that sodium sulfhydrate (NaHS, a donor of H2S) down-regulated the expression of c-fos and

Ying Han; Jiong Qin; Xingzhi Chang; Zhixian Yang; Dingfang Bu; Junbao Du

2005-01-01

454

Measurement of low concentration and nano-quantity hydrogen sulfide in aqueous solution: measurement mechanisms and limitations  

Microsoft Academic Search

To measure hydrogen sulfide (H2S) level in biological samples in vivo on a real-time basis with high resolution is greatly needed for advancing our understanding of the biological role of H2S. Traditional H2S measurements usually need large tissue samples and complex procedures. However, H2S concentration is very low in human bodies and the tissue sample is limited for medical treatment

X. C. Wu; R. Sammynaiken; W. J. Zhang; D. Q. Wu; Q. Yang; W. Yang; R. Wang

2007-01-01

455

Electro-acupuncture protects against hypoxic–ischemic brain-damaged immature rat via hydrogen sulfide as a possible mediator  

Microsoft Academic Search

We investigated whether hydrogen sulfide (H2S) may be a mediator of electro-acupuncture (EA) stimulation treatment for hypoxic–ischemic brain-damage (HIBD). We studied a HIBD 7-day-old rat model with 4 types of treatments: (1) 14 sessions of EA; (2) hydroxylamine (HA), an inhibitor of cystathionine-?-synthase (CBS), the key enzyme of H2S generation; (3) both EA and HA; or (4) no treatment. Sham-treated

Ying Liu; Li-Ping Zou; Jun-Bao Du; Virginia Wong

2010-01-01

456