Experimental study of nitrogen oxide absorption by a liquid nitrogen tetroxide flow

Energy Technology Data Exchange (ETDEWEB)

Verzhinskaya, A B; Saskovets, V V; Borovik, T F

1984-01-01

The system of N/sub 2/O/sub 4/ based coolant regeneration needs productive and efficient absorbers, providing effective production of nitrogen oxide, decreasing upon NPP operation at the expense of radiation-thermal decomposition. The experimental istallation flowsheet for studying the nitrogen oxide absorbtion by liquid nitrogen tetroxide is given. The experiments have been carried out in removable test sections, looked like helical tubes with internal steam-and-liquid mixture flow and external water cooling. Six test sections with variable geometry factors have been manufactured. The plotted results of the experiments are given as dependences of extraction level and mass transfer volumetric coefficients on the geometry factor, pressure and Froude number.

Preparation and use of nitrogen (2) oxide of special purity for production of oxygen and nitrogen isotopes

International Nuclear Information System (INIS)

Polevoj, A.S.

1989-01-01

Problems related with production of oxygen and nitrogen isotopes by means of low-temperature rectification of nitrogen (2) oxide are analyzed. Special attention, in particular, is payed to the techniques of synthesis and high purification of initial NO, utilization of waste flows formed during isotope separation. Ways to affect the initial isotope composition of nitrogen oxide and the rate of its homogeneous-isotope exchange, which provide for possibility of simultaneous production of oxygen and nitrogen isotopes by means of NO rectification, are considered. Description of a new technique for high purification of nitrogen oxide, prepared at decomposition of nitric acid by sulfurous anhydride, suggested by the author is presented

WHO environmental health criteria for oxides of nitrogen

Energy Technology Data Exchange (ETDEWEB)

1977-01-01

A report in preparation by the World Health Organization (WHO), Geneva, on the Environmental Health Criteria for Oxides of Nitrogen is summarized. This report will be published under the joint sponsorship of the United Nations Environment Program (UNEP) and WHO. Chemistry and analytical methods, sources of oxides of nitrogen, environmental levels and exposures, effects on experimental animals, effects on man, and evaluation of health risks are discussed. Further research on the reaction of sensitive biological systems to nitrogen dioxide and oxidants, on the biological effects of nitric acid and nitrates, on the possibility of delayed effects, on epidemiological studies of occupational and community groups, and on asthmatic subjects and persons with cardiopulmonary disease was recommended.

Nitrogen Oxide Emission, Economic Growth and Urbanization in China: a Spatial Econometric Analysis

Science.gov (United States)

Zhou, Zhimin; Zhou, Yanli; Ge, Xiangyu

2018-01-01

This research studies the nexus of nitrogen oxide emissions and economic development/urbanization. Under the environmental Kuznets curve (EKC) hypothesis, we apply the analysis technique of spatial panel data in the STIRPAT framework, and thus obtain the estimated impacts of income/urbanization on nitrogen oxide emission systematically. The empirical findings suggest that spatial dependence on nitrogen oxide emission distribution exist at provincial level, and the inverse N-shape EKC describes both income-nitrogen oxide and urbanization-nitrogen oxide nexuses. In addition, some well-directed policy advices are made to reduce the nitrogen oxide emission in future.

Method of removing oxides of sulfur and oxides of nitrogen from exhaust gases

Science.gov (United States)

Walker, Richard J.

1986-01-01

A continuous method is presented for removing both oxides of sulfur and oxides of nitrogen from combustion or exhaust gases with the regeneration of the absorbent. Exhaust gas is cleaned of particulates and HCl by a water scrub prior to contact with a liquid absorbent that includes an aqueous solution of bisulfite and sulfite ions along with a metal chelate, such as, an iron or zinc aminopolycarboxylic acid. Following contact with the combustion gases the spent absorbent is subjected to electrodialysis to transfer bisulfite ions into a sulfuric acid solution while splitting water with hydroxide and hydrogen ion migration to equalize electrical charge. The electrodialysis stack includes alternate layers of anion selective and bipolar membranes. Oxides of nitrogen are removed from the liquid absorbent by air stripping at an elevated temperature and the regenerated liquid absorbent is returned to contact with exhaust gases for removal of sulfur oxides and nitrogen oxides.

Continuous determination of nitric oxide and nitrogen dioxide in the atmosphere

Energy Technology Data Exchange (ETDEWEB)

Yanagisawa, S; Yamate, N; Mitsuzawa, S; Mori, M

1966-10-01

Continuous determinations of nitric oxide and nitrogen dioxide in that atmospheric air by the use of a modified Saltzman reagent is described. Measurement was made intermittently, once every 30 min., by an automatic continuous analyzer equipped with a single-path colorimeter. The response of the analyzer was obtained as an average of the concentration of nitrogen oxides over a period of 25 min. Two bubblers were used for absorbing nitrogen oxides into the modified Saltzman reagent, whose transmittance was measured for the determination. One bubbler was designed to absorb nitrogen dioxide, and the other, nitric oxide plus nitrogen dioxide after the oxidation of the nitric oxide by permanganate. The oxidizing efficiency of the permanganate was 96-100%. The acetic acid in the Saltzman reagent was replaced with n-propyl alcohol in the modified Saltzman reagent; the spontaneous coloration and corrosive quality of the reagent was decreased by this substitution. The concentration of nitric oxide was obtained from the difference between the two responses of the analyzer, while the concentration of nitrogen dioxide could be read directly from the indication of the recorder. The transmittance ratio method was applied to the measurements, accurate determinations were possible, even at high blank values. Therefore, the reagent was used repeatedly by cycling it on the basis of measuring the difference in the coloration of the reagent before and after the absorption of nitrogen oxides. The analyzer could be used for a long period without changing the reagent.

Kinetics of irreversible thermal decomposition of dissociating nitrogen dioxide with nitrogen oxide or oxygen additions

International Nuclear Information System (INIS)

Gvozdev, A.A.

1987-01-01

The effect of NO or O 2 admixtures on kinetics of the irreversible thermal decomposition of nitrogen dioxide at temperatures 460-520 deg C and pressures 4-7 MPa has been studied. It follows from experimental data that the rate of N 2 O 4 formation reduces with the increase of partial pressure of oxygen or decrease of partial pressure of nitrogen oxide. The same regularity is seen for the rate of nitrogen formation. The rate constants of N 2 O formation in dissociating nitrogen tetroxide with oxygen or nitrogen oxide additions agree satisfactorily with previously published results, obtained in stoichiometric mixtures. The appreciable discrepancy at 520 deg C is bind with considerable degree of nitrogen oxide transformation which constitutes approximately 14%. It is determined that the kinetics of formation of the products of irreversible N 2 O and N 2 decomposition in stoichiometric and non-stoichiometric 2NO 2 ↔ 2NO+O 2 mixtures is described by identical 3NO → N 2 O+NO 2 and N 2 O+NO → N 2 +NO 2 reactions

40 CFR 90.318 - Oxides of nitrogen analyzer calibration.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Oxides of nitrogen analyzer calibration. 90.318 Section 90.318 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Emission Test Equipment Provisions § 90.318 Oxides of nitrogen analyzer calibration. (a) Calibrate the...

40 CFR 89.321 - Oxides of nitrogen analyzer calibration.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Oxides of nitrogen analyzer calibration. 89.321 Section 89.321 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Test Equipment Provisions § 89.321 Oxides of nitrogen analyzer calibration. (a) The chemiluminescent...

Oxidation of Zircaloy-4 in steam-nitrogen mixtures at 600-1200 °C

Science.gov (United States)

Steinbrueck, Martin; da Silva, Fabio Oliveira; Grosse, Mirco

2017-07-01

High-temperature oxidation of zirconium alloys in steam-nitrogen atmospheres may be relevant during various nuclear accident scenarios. Therefore, isothermal oxidation tests with Zircaloy-4 in steam-nitrogen mixtures have been performed at 600, 800, 1000, and 1200 °C using thermogravimetry. The gas compositions were varied between 0 and 100 vol% nitrogen including 0.1 and 90 vol%. The strong effect of nitrogen on the oxidation kinetics of zirconium alloys was confirmed in these tests in mixed steam-nitrogen atmospheres. Even very low concentrations of nitrogen (starting from less than 1 vol%) strongly increase reaction kinetics. Nitrogen reduces transition time from protective to non-protective oxide scale (breakaway). The formation of zirconium nitride, ZrN, and its re-oxidation is the main reason for the highly porous oxide scales after transition. The results of this study have shown the safety relevant role of nitrogen during severe accidents and, more generally, suggest the need of using well controlled gas atmospheres for experiments on oxidation of zirconium alloys.

Legislative measures for suppressing emission of nitrogen oxides from thermal power stations

Energy Technology Data Exchange (ETDEWEB)

Kotler, V.R.

1987-11-01

Reviews measures taken by some countries to control emission of nitrogen oxides from thermal power stations run on solid fuels, mazout and gas. Refers to maximum permissible concentrations of nitrogen oxides in USA (100 mg/m/sup 3/), Canada (460 mg/m/sup 3/), Japan (41-62 mg/m/sup 3/) and several European countries. Discusses legislative measures in FRG (Federal Regulations BImSchG), particularly Instruction No. 13 BImSchV concerning large boilers run on solid fuels or mazout (continuous monitoring of nitrogen oxide emission into atmosphere, equipping old boilers with means of reducing nitrogen oxide emission, reduction of acid rain). Gives maximum permissible concentrations of nitrogen oxides for new boilers agreed by various countries. 5 refs.

Numerical modelling of emissions of nitrogen oxides in solid fuel combustion.

Science.gov (United States)

Bešenić, Tibor; Mikulčić, Hrvoje; Vujanović, Milan; Duić, Neven

2018-06-01

Among the combustion products, nitrogen oxides are one of the main contributors to a negative impact on the environment, participating in harmful processes such as tropospheric ozone and acid rains production. The main source of emissions of nitrogen oxides is the human combustion of fossil fuels. Their formation models are investigated and implemented with the goal of obtaining a tool for studying the nitrogen-containing pollutant production. In this work, numerical simulation of solid fuel combustion was carried out on a three-dimensional model of a drop tube furnace by using the commercial software FIRE. It was used for simulating turbulent fluid flow and temperature field, concentrations of the reactants and products, as well as the fluid-particles interaction by numerically solving the integro-differential equations describing these processes. Chemical reactions mechanisms for the formation of nitrogen oxides were implemented by the user functions. To achieve reasonable calculation times for running the simulations, as well as efficient coupling with the turbulent mixing process, the nitrogen scheme is limited to sufficiently few homogeneous reactions and species. Turbulent fluctuations that affect the reaction rates of nitrogen oxides' concentration are modelled by probability density function approach. Results of the implemented model for nitrogen oxides' formation from coal and biomass are compared to the experimental data. Temperature, burnout and nitrogen oxides' concentration profiles are compared, showing satisfactory agreement. The new model allows the simulation of pollutant formation in the real-world applications. Copyright © 2018 Elsevier Ltd. All rights reserved.

Oxidation of Zircaloy-4 in steam-nitrogen mixtures at 600–1200 °C

Energy Technology Data Exchange (ETDEWEB)

Steinbrueck, Martin, E-mail: martin.steinbrueck@kit.edu; Oliveira da Silva, Fabio; Grosse, Mirco

2017-07-15

High-temperature oxidation of zirconium alloys in steam-nitrogen atmospheres may be relevant during various nuclear accident scenarios. Therefore, isothermal oxidation tests with Zircaloy-4 in steam-nitrogen mixtures have been performed at 600, 800, 1000, and 1200 °C using thermogravimetry. The gas compositions were varied between 0 and 100 vol% nitrogen including 0.1 and 90 vol%. The strong effect of nitrogen on the oxidation kinetics of zirconium alloys was confirmed in these tests in mixed steam-nitrogen atmospheres. Even very low concentrations of nitrogen (starting from less than 1 vol%) strongly increase reaction kinetics. Nitrogen reduces transition time from protective to non-protective oxide scale (breakaway). The formation of zirconium nitride, ZrN, and its re-oxidation is the main reason for the highly porous oxide scales after transition. The results of this study have shown the safety relevant role of nitrogen during severe accidents and, more generally, suggest the need of using well controlled gas atmospheres for experiments on oxidation of zirconium alloys.

40 CFR 86.523-78 - Oxides of nitrogen analyzer calibration.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Oxides of nitrogen analyzer calibration. 86.523-78 Section 86.523-78 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Emission Regulations for 1978 and Later New Motorcycles; Test Procedures § 86.523-78 Oxides of nitrogen...

Process for the removal of sulfur oxides and nitrogen oxides from flue gas

International Nuclear Information System (INIS)

Elshout, R.V.

1992-01-01

This patent describes a continuous process for removing sulfur oxide and nitrogen oxide contaminants from the flue gas generated by industrial power plants and boiler systems burning sulfur containing fossil fuels and for converting these contaminants, respectively, into recovered elemental liquid sulfur and nitrogen ammonia and mixtures thereof. It comprises removing at least a portion of the flue gas generated by a power plant or boiler system upstream of the stack thereof; passing the cooled and scrubbed flue gas through an adsorption system; combining a first portion of the reducing gas stream leaving the adsorbers of the adsorption system during regeneration thereof and containing sulfur oxide and nitrogen oxide contaminants with a hydrogen sulfide rich gas stream at a temperature of about 400 degrees F to about 600 degrees F and passing the combined gas streams through a Claus reactor-condenser system over a catalyst in the reactor section thereof which is suitable for promoting the equilibrium reaction between the hydrogen sulfide and the sulfur dioxide of the combined streams to form elemental sulfur

Integrated Science Assessment (ISA) for Oxides of Nitrogen ...

Science.gov (United States)

This draft ISA document represents a concise synthesis and evaluation of the most policy-relevant science and will ultimately provide the scientific bases for EPA’s decision on retaining or revising the current secondary standards for NO2, SO2, PM 2.5 and PM 10 since the prior release of the assessment. The intent of the ISA, according to the CAA, is to “accurately reflect the latest scientific knowledge expected from the presence of [a] pollutant in ambient air” (U.S. Code, 1970a, 1970b). It includes scientific research from atmospheric sciences, exposure and deposition, biogeochemistry, hydrology, soil science, marine science, plant physiology, animal physiology, and ecology conducted at multiple scales (e.g., population, community, ecosystem, landscape levels). Key information and judgments formerly found in the Air Quality Criteria Documents (AQCDs) for oxides of nitrogen, oxides of nitrogen and particulate matter for ecological effects are included; Appendixes provide additional details supporting the ISA. Together, the ISA and Appendixes serve to update and revise the last oxides of nitrogen and oxides of sulfur ISA which was published in 2008 and the ecological portion of the last particulate matter ISA, which was published in 2009.

40 CFR 52.65 - Control Strategy: Nitrogen oxides.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Control Strategy: Nitrogen oxides. 52.65 Section 52.65 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Alabama § 52.65 Control Strategy: Nitrogen...

Liver changes under the influence of chronic experimental intoxication with nitrogen oxides

Energy Technology Data Exchange (ETDEWEB)

Kosmider, S; Misiewicz, A

1973-01-01

Male guinea pigs were divided into three groups: a control group; a group of animals breathing air containing 1 ppM nitrogen oxides during 6 months, 8 hr/day; and third group exposed to products of reactions between nitrogen oxide and gaseous ammonia. The animals lived through the 6 mo with no increase in mortality. The body weight of the animals exposed to nitrogen oxides increased during the 6 mo by 62 g on the average, while in the control group the body weight increased by 395 g on the average. In homogenates of the livers of the animals exposed to nitrogen oxides, the activities of aldolase, lactic dehydrogenase, acid, and alkaline phosphatase increased, and the activities of cholinesterase, ceruloplasmin, and aminotransferases (aspartic and alanine) decreased. Neutralization of NO/sub x/ by gaseous ammonia restored the disorders in enzyme activities in the liver of the animals exposed to nitrogen oxides to their normal values. The study was statistically analyzed. The livers of the animals exposed to nitrogen oxides contained small foci of necrosis, and hemorrhages could be observed. In some animals, fatty degeneration of the liver could be observed. The changes in the liver can also be associated with inhibited protein synthesis, enhanced catabolic processes, and hypovitaminosis.

The defect chemistry of nitrogen in oxides: A review of experimental and theoretical studies

International Nuclear Information System (INIS)

Polfus, Jonathan M.; Norby, Truls; Haugsrud, Reidar

2013-01-01

Incorporation of nitrogen into oxides has in recent years received increased attention as a variable for tuning their functional properties. A vast number of reports have been devoted to improving the photocatalytic properties of TiO 2 , p-type charge carrier concentration in ZnO and the ionic transport properties of ZrO 2 by nitrogen doping. In comparison, the fundamentals of the nitrogen related defect chemistry for a wider range of oxides have been less focused upon. In the present contribution, we review experimental and computational investigations of the nitrogen related defect chemistry of insulating and semiconducting oxides. The interaction between nitrogen and protons is important and emphasized. Specifically, the stability of nitrogen defects such as N O / , NH O × and (NH 2 ) O • is evaluated under various conditions and their atomistic and electronic structure is presented. A final discussion is devoted to the role of nitrogen with respect to transport properties and photocatalytic activity of oxides. - Graphical abstract: Experimental and theoretical investigations of the nitrogen related defect chemistry of a range of wide band gap oxides is reviewed. The interaction between nitrogen dopants and protons is emphasized and described through the atomistic and electronic structure as well as defect chemical processes involving NH and NH 2 defects. Consequently, the physical properties of oxides containing such species are discussed with respect to e.g., diffusion and photocatalytic properties. Highlights: ► Experimental and theoretical investigations of the nitrogen and hydrogen related defect chemistry of wide band gap oxides is reviewed. ► The interaction between nitrogen dopants and protons is important and emphasized. ► Diffusion and photocatalytic properties of N-doped oxides are discussed.

Reducing nitrogen oxides from power stations

International Nuclear Information System (INIS)

Scheller, W.

1986-12-01

The report contains 17 individual lectures of the seminar included in databanks. The lectures concern combustion and waste gas measures for reducing the sulfur dioxide and nitrogen oxide emission from coal-fired and gas-fired power stations. (PW) [de

Nitrous oxide production by lithotrophic ammonia-oxidizing bacteria and implications for engineered nitrogen-removal systems.

Science.gov (United States)

Chandran, Kartik; Stein, Lisa Y; Klotz, Martin G; van Loosdrecht, Mark C M

2011-12-01

Chemolithoautotrophic AOB (ammonia-oxidizing bacteria) form a crucial component in microbial nitrogen cycling in both natural and engineered systems. Under specific conditions, including transitions from anoxic to oxic conditions and/or excessive ammonia loading, and the presence of high nitrite (NO₂⁻) concentrations, these bacteria are also documented to produce nitric oxide (NO) and nitrous oxide (N₂O) gases. Essentially, ammonia oxidation in the presence of non-limiting substrate concentrations (ammonia and O₂) is associated with N₂O production. An exceptional scenario that leads to such conditions is the periodical switch between anoxic and oxic conditions, which is rather common in engineered nitrogen-removal systems. In particular, the recovery from, rather than imposition of, anoxic conditions has been demonstrated to result in N₂O production. However, applied engineering perspectives, so far, have largely ignored the contribution of nitrification to N₂O emissions in greenhouse gas inventories from wastewater-treatment plants. Recent field-scale measurements have revealed that nitrification-related N₂O emissions are generally far higher than emissions assigned to heterotrophic denitrification. In the present paper, the metabolic pathways, which could potentially contribute to NO and N₂O production by AOB have been conceptually reconstructed under conditions especially relevant to engineered nitrogen-removal systems. Taken together, the reconstructed pathways, field- and laboratory-scale results suggest that engineering designs that achieve low effluent aqueous nitrogen concentrations also minimize gaseous nitrogen emissions.

40 CFR 52.136 - Control strategy for ozone: Oxides of nitrogen.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Control strategy for ozone: Oxides of nitrogen. 52.136 Section 52.136 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... for ozone: Oxides of nitrogen. EPA is approving an exemption request submitted by the State of Arizona...

Conductivity study of nitrogen-doped calcium zinc oxide prepared by spray pyrolysis

International Nuclear Information System (INIS)

Hsu, Yu-Ting; Lan, Wen-How; Huang, Kai-Feng; Lin, Jia-Ching; Chang, Kuo-Jen

2016-01-01

In this study, the spray pyrolysis method was used to prepare unintentionally doped and nitrogen-doped calcium zinc oxide films by using zinc acetate, calcium nitrate precursor, and ammonium acetate precursor. Morphological and structural analyses were conducted using scanning electron microscopy and X-ray diffraction. The results indicated that film grain size decreased as the nitrogen doping was increased. Both calcium oxide and zinc oxide structures were identified in the unintentionally doped calcium zinc oxide. When nitrogen doping was introduced, the film mainly exhibited a zinc oxide structure with preferred (002) and (101) orientations. The concentration and mobility were investigated using a Hall measurement system. P-type films with a mobility and concentration of 10.6 cm"2 V"−"1 s"−"1 and 2.8×10"1"7 cm"−"3, respectively, were obtained. Moreover, according to a temperature-dependent conductivity analysis, an acceptor state with activation energy 0.266 eV dominated the p-type conduction for the unintentionally doped calcium zinc oxide. By contrast, a grain boundary with a barrier height of 0.274–0.292 eV dominated the hole conduction for the nitrogen-doped calcium zinc oxide films.

Interaction of oxides of nitrogen and aromatic hydrocarbons under simulated atmospheric conditions

International Nuclear Information System (INIS)

Obrien, R.J.; Green, P.J.; Doty, R.A.; Vanderzanden, J.W.; Easton, R.R.; Irwin, R.P.

1979-01-01

The reactions of nitrogen oxides with aromatic hydrocarbons under simulated atmospheric conditions are investigated. Gaseous reaction products formed when toluene is irradiated under simulated atmospheric conditions in the presence of nitrogen oxides were analyzed by gas chromatography. Reaction products detected include acetylene, water, acetaldehyde, acetone, toluene, benzaldehyde, ortho-, meta- and para-cresol, benzyl nitrate and meta- and para-nitrotoluene. Reaction mechanisms yielding the various products are illustrated. The assumption that all the nitrogen oxides observed to be lost from the reaction products can be accounted for by nitric acid formation in the absence of ozone formation is verified by a model in which the hydroxyl radical is assumed to be the only means of removing toluene. Under conditions in which ozone is formed, nitrogen oxide loss is accounted for by ozone formation in addition to nitric acid formation

The adsorption of nitrogen oxides on crystalline ice

Directory of Open Access Journals (Sweden)

T. Bartels

2002-01-01

Full Text Available The partitioning of nitrogen oxides between ice and air is of importance to the ozone budget in the upper troposphere. In the present study, adsorption of nitrogen oxides on ice was investigated at atmospheric pressure using a chromatographic technique with radioactively labelled nitrogen oxides at low concentrations. The measured retentions solely depended on molecular adsorption and were not influenced by dimerisation, formation of encapsulated hydrates on the ice surface, dissociation of the acids, nor by migration into a quasi-liquid layer or grain boundaries. Based on the chromatographic retention and the model of thermo-chromatography, the standard adsorption enthalpy of -20 kJ mol-1 for NO, -22kJ mol-1 for NO2, -30kJ mol-1 for peroxyacetyl nitrate, -32kJ mol-1 for HON} and -44 kJ mol-1 for HNO3 was calculated. To perform those calculations within the model of thermo-chromatography, the standard adsorption entropy was calculated based on statistical thermodynamics. In this work, two different choices of standard states were applied, and consequently different values of the standard adsorption entropy, of either between -39 kJ mol-1 and -45kJ mol-1, or -164 kJ mol-1 and -169 kJ mol-1 for each nitrogen oxide were derived. The standard adsorption enthalpy was identical for both standard adsorption entropies and thus shown to be independent of the choice of standard state. A brief outlook on environmental implications of our findings indicates that adsorption on ice might be an important removal process of HNO3. In addition, it might be of some importance for HONO and peroxyacetyl nitrate and irrelevant for NO and NO2.

Gas phase reactions of nitrogen oxides with olefins

Energy Technology Data Exchange (ETDEWEB)

Altshuller, A P; Cohen, I

1961-01-01

The nature of the condensation products formed in the gas phase reactions of nitrogen dioxide and nitric oxide with pentene-1, 2-methylbutene-2, and 2-methylbutadiene-1,3 was investigated. The reactants were combined at partial pressures in the range of 0.1 to 2.5 mm with the total pressure at one atmosphere. The products were determined by infrared and ultraviolet spectroscopy and colorimetry. The condensates included primary and secondary nitro compounds and alkyl nitrates. Strong hydroxyl and single bond carbon to oxygen stretching vibrations indicate the presence of either nitroalcohols or simple aliphatic alcohols formed through oxidation reactions. Carbonyl stretching frequencies observable in some of the reactions support the conclusion that a portion of the reactants disappear by oxidation rather than by nitration processes. The available results do not indicate the presence of appreciable amounts of tert.-nitro compounds, conjugated nitro-olefins, or gem-dinitro-alkanes. The reactivities of the olefins with the nitrogen oxides are in the decreasing order: 2-methyl-butadiene-1,3, 2-methylbutene-2, pentene-1. 20 references.

Gradual combustion - method for nitrogen oxide suppression during brown coal combustion

Energy Technology Data Exchange (ETDEWEB)

Kotler, V.P.; Verzakov, V.N.; Lobov, T.V.

1990-10-01

Discusses combustion of brown coal in BKZ-500-140-1 boilers and factors that influence emission of nitrogen oxides. Temperature distribution in the furnace was evaluated. Effects of burner position, burner number and burner type as well as air excess ratio on chemical reactions during brown coal combustion, formation of nitrogen oxides and their emission were comparatively evaluated. Analyses showed that by optimum arrangement of burners and selecting the optimum air excess ratio a part of nitrogen oxides formed during the initial phase of combustion was reduced to molecular nitrogen in the second phase. On the basis of evaluations the following recommendations for furnace design are made: use of straight-flow burners characterized by a reduced mixing ratio with secondary air, parallel arrangement of burners which guarantees mixing of the combustion products from the burners with stable and unstable combustion (products of incomplete coal combustion), reducing the air excess ratio to below 1.0. 5 refs.

Nitrogen removal from wastewater by a catalytic oxidation method.

Science.gov (United States)

Huang, T L; Macinnes, J M; Cliffe, K R

2001-06-01

The ammonia-containing waste produced in industries is usually characterized by high concentration and high temperature, and is not treatable by biological methods directly. In this study, a hydrophobic Pt/SDB catalyst was first used in a trickle-bed reactor to remove ammonia from wastewater. In the reactor, both stripping and catalytic oxidation occur simultaneously. It was found that higher temperature and higher oxygen partial pressure enhanced the ammonia removal. A reaction pathway, which involves oxidizing ammonia to nitric oxide, which then further reacts with ammonia to produce nitrogen and water, was confirmed. Small amounts of by-products, nitrites and nitrates were also detected in the resultant reaction solution. These compounds came from the absorption of nitrogen oxides. Both the minimum NO2- selectivity and maximum ammonia removal were achieved when the resultant pH of treated water was near 7.5 for a feed of unbuffered ammonia solution.

40 CFR 89.112 - Oxides of nitrogen, carbon monoxide, hydrocarbon, and particulate matter exhaust emission standards.

Science.gov (United States)

2010-07-01

....112 Oxides of nitrogen, carbon monoxide, hydrocarbon, and particulate matter exhaust emission... emissions of oxides of nitrogen, carbon monoxide, hydrocarbon, and nonmethane hydrocarbon are measured using... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Oxides of nitrogen, carbon monoxide...

Health risk evaluation of nitrogen oxides

Energy Technology Data Exchange (ETDEWEB)

Berglund, M.; Ewetz, L.; Gustafsson, L.; Moldeus, P.; Pershagen, G.; Victorin, K. [Karolinska Inst., Stockholm (Sweden). Inst. of Environmental Medicine

1995-12-31

At the request of the Swedish Environmental Protection Agency a criteria document on nitrogen oxides has been prepared, and is intended to serve as a basis for revised air quality standards in Sweden. The criteria document is based on a thorough literature survey, and the health risk assessment is summarized in this presentation. The present standard for nitrogen dioxide (NO{sub 2}) is 110 {mu}g/m{sup 3} as 1-hour mean (98th percentile); 75 {mu}g/m{sup 3} as 24- hour mean (98th percentile); and 50 {mu}g/m{sup 3} as 6-month mean (arithmetic eman during winter half-year). (author)

Health risk evaluation of nitrogen oxides

Energy Technology Data Exchange (ETDEWEB)

Berglund, M; Ewetz, L; Gustafsson, L; Moldeus, P; Pershagen, G; Victorin, K [Karolinska Inst., Stockholm (Sweden). Inst. of Environmental Medicine

1996-12-31

At the request of the Swedish Environmental Protection Agency a criteria document on nitrogen oxides has been prepared, and is intended to serve as a basis for revised air quality standards in Sweden. The criteria document is based on a thorough literature survey, and the health risk assessment is summarized in this presentation. The present standard for nitrogen dioxide (NO{sub 2}) is 110 {mu}g/m{sup 3} as 1-hour mean (98th percentile); 75 {mu}g/m{sup 3} as 24- hour mean (98th percentile); and 50 {mu}g/m{sup 3} as 6-month mean (arithmetic eman during winter half-year). (author)

Conversion of sulfur and nitrogen oxides in air under exposure to microsecond electron beams

International Nuclear Information System (INIS)

Denisov, G.V.; Kuznetsov, D.L.; Novoselov, Yu.N.; Tkachenko, R.M.

2002-01-01

Flue gases of power plants realizing sulfur and nitrogen oxides into the atmosphere represent one of the environmental pollution sources. Paper presents the results of experimental investigations of conversion of sulfur and nitrogen oxides in the ionized gas mixture simulating composition of off-gases of thermal power stations. Pulse beam of microsecond duration electrons was used as a source of ionization. Mutual influence of both types of oxides on process of their conversion is shown. One studied possible kinetic mechanisms to remove sulfur and nitrogen oxides from gaseous mixture [ru

Supercapacitors based on nitrogen-doped reduced graphene oxide and borocarbonitrides

Science.gov (United States)

Gopalakrishnan, K.; Moses, Kota; Govindaraj, A.; Rao, C. N. R.

2013-12-01

Nitrogen-doped reduced graphene oxide (RGO) samples with different nitrogen content, prepared by two different methods, as well as nitrogen-doped few-layer graphene have been investigated as supercapacitor electrodes. Two electrode measurements have been carried out both in aqueous (6M KOH) and in ionic liquid media. Nitrogen-doped reduced graphene oxides exhibit satisfactory specific capacitance, the values reaching 126F/g at a scan rate of 10mV/s in aqueous medium. Besides providing supercapacitor characteristics, the study has shown the nitrogen content and surface area to be important factors. High surface-area borocarbonitrides, BxCyNz, prepared by the urea route appear to be excellent supercapacitor electrode materials. Thus, BC4.5N exhibits a specific capacitance of 169F/g at a scan rate of 10mV/s in aqueous medium. In an ionic liquid medium, nitrogen-doped RGO and BC4.5N exhibit specific capacitance values of 258F/g and 240F/g at a scan rate of 5mV/s. The ionic liquid enables a larger operating voltage range of 0.0-2.5V compared to 0.0-1V in aqueous medium.

Method for combined removal of mercury and nitrogen oxides from off-gas streams

Science.gov (United States)

Mendelsohn, Marshall H [Downers Grove, IL; Livengood, C David [Lockport, IL

2006-10-10

A method for removing elemental Hg and nitric oxide simultaneously from a gas stream is provided whereby the gas stream is reacted with gaseous chlorinated compound to convert the elemental mercury to soluble mercury compounds and the nitric oxide to nitrogen dioxide. The method works to remove either mercury or nitrogen oxide in the absence or presence of each other.

Kinetics of oxidation of the alloy-MR-47VP with nitrogen dioxide

International Nuclear Information System (INIS)

Vasil'eva, A.G.; Rakova, N.N.; Vladimirskaya, I.N.; Kabanova, O.V.; Miklyaev, A.D.

1978-01-01

The kinetic dependences of oxidation of MR-47VP grade molybdenum-rhenium alloy with nitrogen dioxide have been examined within the temperature range of 350 to 550 deg C. It has been shown that the processes take place in the transition region. The specific oxidation rate of the alloy with the nitrogen dioxide is but small, and it is comparable as to its value with the specific rate of its oxidation in oxygen under identical conditions

Nitrogen oxides in the troposphere – What have we learned from satellite measurements?

Directory of Open Access Journals (Sweden)

Richter A.

2009-02-01

Full Text Available Nitrogen oxides are key species in the troposphere where they are linked to ozone formation and acid rain. The sources of nitrogen oxides are anthropogenic to large extend, mainly through combustion of fossil fuels. Satellite observations of NO2 provide global measurements of nitrogen oxides since summer 1995, and these data have been applied for many studies on the emission sources and strengths, the chemistry and the transport of NOx. In this paper, an overview will be given on satellite measurements of NO2 , some examples of typical applications and an outlook on future prospects.

40 CFR 52.326 - Area-wide nitrogen oxides (NOX) exemptions.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Area-wide nitrogen oxides (NOX) exemptions. 52.326 Section 52.326 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Colorado § 52.326 Area-wide nitrogen...

78 FR 47253 - Approval and Promulgation of Air Quality Implementation Plans; Maine; Oxides of Nitrogen...

Science.gov (United States)

2013-08-05

... Promulgation of Air Quality Implementation Plans; Maine; Oxides of Nitrogen Exemption and Ozone Transport... is proposing to approve Maine's October 13, 2012, request for an exemption from the nitrogen oxides... from Stephen D. Page, Director, OAQPS, dated January 14, 2005, entitled ``Guidance on Limiting Nitrogen...

Effect of nitrogen precursors on the electrochemical performance of nitrogen-doped reduced graphene oxide towards oxygen reduction reaction

International Nuclear Information System (INIS)

Soo, Li Ting; Loh, Kee Shyuan; Mohamad, Abu Bakar; Daud, Wan Ramli Wan; Wong, Wai Yin

2016-01-01

A series of nitrogen-doped reduced graphene oxides (NGs) with different ratios are synthesized by thermal annealing of graphene oxide with melamine or urea. The total nitrogen content in NG is high, with values of up to 5.88 at.%. The NG samples prepared by melamine exhibited thin transparent graphene sheets structure, with consist of higher nitrogen doping level and quaternary N content compared to those NG samples prepared from urea. Electrochemical characterizations show that NG is a promising metal-free electrocatalyst for an oxygen reduction reaction (ORR). Incorporation of nitrogen atoms into graphene basal plane can enhances its electrocatalytic activity toward ORR in alkaline media. The onset potential and mean number of electron transfers on NG 1 are −0.10 V and 3.80 respectively, which is higher than that of reduced graphene oxide (−0.15 V, 3.52). This study suggests that quaternary-N of the NG samples is the active site which determines the ORR activity Moreover, the NG samples with the transparent layer of graphene-like structure have better ORR performances than that of bulk graphite-like NG samples. - Highlights: • Synthesis of nitrogen-doped graphene (NG) via thermal annealing. • The effects of the nitrogen precursors on the synthesized NG are discussed. • Electrochemical performances of the NG are correlated to N doping and EASA. • Graphitic-N is proposed to be the active site for ORR.

Effect of nitrogen precursors on the electrochemical performance of nitrogen-doped reduced graphene oxide towards oxygen reduction reaction

Energy Technology Data Exchange (ETDEWEB)

Soo, Li Ting, E-mail: nicolesoo90@gmail.com [Fuel Cell Institute, Universiti Kebangsaan Malaysia, 43600 Bangi UKM, Selangor (Malaysia); Loh, Kee Shyuan, E-mail: ksloh@ukm.edu.my [Fuel Cell Institute, Universiti Kebangsaan Malaysia, 43600 Bangi UKM, Selangor (Malaysia); Mohamad, Abu Bakar, E-mail: drab@ukm.edu.my [Fuel Cell Institute, Universiti Kebangsaan Malaysia, 43600 Bangi UKM, Selangor (Malaysia); Department of Chemical and Process Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 Bangi UKM, Selangor (Malaysia); Daud, Wan Ramli Wan, E-mail: wramli@ukm.edu.my [Fuel Cell Institute, Universiti Kebangsaan Malaysia, 43600 Bangi UKM, Selangor (Malaysia); Department of Chemical and Process Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 Bangi UKM, Selangor (Malaysia); Wong, Wai Yin, E-mail: waiyin.wwy@gmail.com [Fuel Cell Institute, Universiti Kebangsaan Malaysia, 43600 Bangi UKM, Selangor (Malaysia); School of Engineering, Taylor' s University' s Lakeside Campus, No. 1, Jalan Taylor' s, 46500 Subang Jaya, Selangor (Malaysia)

2016-08-25

A series of nitrogen-doped reduced graphene oxides (NGs) with different ratios are synthesized by thermal annealing of graphene oxide with melamine or urea. The total nitrogen content in NG is high, with values of up to 5.88 at.%. The NG samples prepared by melamine exhibited thin transparent graphene sheets structure, with consist of higher nitrogen doping level and quaternary N content compared to those NG samples prepared from urea. Electrochemical characterizations show that NG is a promising metal-free electrocatalyst for an oxygen reduction reaction (ORR). Incorporation of nitrogen atoms into graphene basal plane can enhances its electrocatalytic activity toward ORR in alkaline media. The onset potential and mean number of electron transfers on NG 1 are −0.10 V and 3.80 respectively, which is higher than that of reduced graphene oxide (−0.15 V, 3.52). This study suggests that quaternary-N of the NG samples is the active site which determines the ORR activity Moreover, the NG samples with the transparent layer of graphene-like structure have better ORR performances than that of bulk graphite-like NG samples. - Highlights: • Synthesis of nitrogen-doped graphene (NG) via thermal annealing. • The effects of the nitrogen precursors on the synthesized NG are discussed. • Electrochemical performances of the NG are correlated to N doping and EASA. • Graphitic-N is proposed to be the active site for ORR.

Volatile organic compounds and oxides of nitrogen. Further emission reductions

Energy Technology Data Exchange (ETDEWEB)

Froste, H [comp.

1997-12-31

This report presents the current status in relation to achievement of the Swedish Environmental target set by Parliament to reduce emission of volatile organic compounds by 50 per cent between 1988 and 2000. It also instructed the Agency to formulate proposed measures to achieve a 50 per cent reduction of emission of nitrogen oxides between 1985 and 2005. The report presents an overall account of emission trends for volatile organic compounds (from all sectors) and nitrogen oxides (from the industry sector) and steps proposed to achieve further emission reductions. 43 refs

Volatile organic compounds and oxides of nitrogen. Further emission reductions

Energy Technology Data Exchange (ETDEWEB)

Froste, H. [comp.

1996-12-31

This report presents the current status in relation to achievement of the Swedish Environmental target set by Parliament to reduce emission of volatile organic compounds by 50 per cent between 1988 and 2000. It also instructed the Agency to formulate proposed measures to achieve a 50 per cent reduction of emission of nitrogen oxides between 1985 and 2005. The report presents an overall account of emission trends for volatile organic compounds (from all sectors) and nitrogen oxides (from the industry sector) and steps proposed to achieve further emission reductions. 43 refs

Community Composition of Nitrous Oxide-Related Genes in Salt Marsh Sediments Exposed to Nitrogen Enrichment.

Science.gov (United States)

Angell, John H; Peng, Xuefeng; Ji, Qixing; Craick, Ian; Jayakumar, Amal; Kearns, Patrick J; Ward, Bess B; Bowen, Jennifer L

2018-01-01

Salt marshes provide many key ecosystem services that have tremendous ecological and economic value. One critical service is the removal of fixed nitrogen from coastal waters, which limits the negative effects of eutrophication resulting from increased nutrient supply. Nutrient enrichment of salt marsh sediments results in higher rates of nitrogen cycling and, commonly, a concurrent increase in the flux of nitrous oxide, an important greenhouse gas. Little is known, however, regarding controls on the microbial communities that contribute to nitrous oxide fluxes in marsh sediments. To address this disconnect, we generated profiles of microbial communities and communities of micro-organisms containing specific nitrogen cycling genes that encode several enzymes ( amoA, norB, nosZ) related to nitrous oxide flux from salt marsh sediments. We hypothesized that communities of microbes responsible for nitrogen transformations will be structured by nitrogen availability. Taxa that respond positively to high nitrogen inputs may be responsible for the elevated rates of nitrogen cycling processes measured in fertilized sediments. Our data show that, with the exception of ammonia-oxidizing archaea, the community composition of organisms involved in the production and consumption of nitrous oxide was altered under nutrient enrichment. These results suggest that previously measured rates of nitrous oxide production and consumption are likely the result of changes in community structure, not simply changes in microbial activity.

Microbiological Diversity Demonstrates the Potential which Collaboratively Metabolize Nitrogen Oxides ( NOx) under Smog Environmental Stress

Science.gov (United States)

Chen, X. Z.; Zhao, X. H.; Chen, X. P.

2018-03-01

Recently, smoggy weather has become a daily in large part of China because of rapidly economic growth and accelerative urbanization. Stressed on the smoggy situation and economic growth, the green and environment-friendly technology is necessary to reduce or eliminate the smog and promote the sustainable development of economy. Previous studies had confirmed that nitrogen oxides ( NOx ) is one of crucial factors which forms smog. Microorganisms have the advantages of quickly growth and reproduction and metabolic diversity which can collaboratively Metabolize various NOx. This study will design a kind of bacteria & algae cultivation system which can metabolize collaboratively nitrogen oxides in air and intervene in the local nitrogen cycle. Furthermore, the nitrogen oxides can be transformed into nitrogen gas or assembled in protein in microorganism cell by regulating the microorganism types and quantities and metabolic pathways in the system. Finally, the smog will be alleviated or eliminated because of reduction of nitrogen oxides emission. This study will produce the green developmental methodology.

Mechanisms of realization of THz-waves of nitrogen oxide occurrence physiological effects

Directory of Open Access Journals (Sweden)

Vyacheslav F. Kirichuk

2013-11-01

Full Text Available In this review, there is generalized material of many experimental researches in interaction of THz-waves molecular emission and absorption spectrum (MEAS of nitrogen oxide occurrence with bioobjects. Thrombocytes and experimental animals were used as bioobjects. The experiments let indicate changes caused by THz-waves: at the cellular, tissular, system, organismic levels. There are all data of changes in physiological mechanisms of reglations at all levels: autocrine, paracrine, endocrine and nervous. There is a complex overview of experimental material firstly performed in the article. There had been shown that the effect of THz-waves of the given occurrence is realized by the changed activity of nitroxidergic system. It had been proved that THz-waves of nitrogen oxide occurrence can stimulate nitrogen oxide producing in organs and tissues in condition of its low concentration. Possible mechanisms of antiaggregative effect of the given waves had been described. There had been shown the possibility of regulating of vascular tone and system hemodynamics with the help of the studying these frequencies. The represented data of lipid peroxidation and enzymatic and nonenzymatic components of organism system under the influence of THz-waves of nitrogen oxide occurrence in stress conditions. Besides, there were shown changes of stress-regulating system activity and in concentration of important mediators - catecholamines and glucocorticosteroids. These data let characterize mechanism of realization of THz-waves basic effects. The research had shown the possibility of THz-waves of nitrogen oxide occurrence usage as a method of natural physiological noninvasive regulation of significant organism functions.

Express analysis of nitrogen oxides in combustion products of energy fuels

Energy Technology Data Exchange (ETDEWEB)

Avdeeva, A A; Tishina, T A; Kormilitsyn, V I

1981-07-01

This paper discusses accuracy of 3 gas analyzers used in the USSR for determination of nitrogen oxide content in smoke emitted to the atmosphere by coal-fired fossil-fuel power plants. UG-2 colorimeter measures content of nitric oxide and nitrogen dioxide with accuracy of about 25% (nominal accuracy amounts to 10%). Its range of measurement does not exceed 0.2 g/m/sup 3/. Duration of measurement is from 5 to 7 min. GKh-4 colorimeter with range from 0 to 0.16 g/m/sup 3/ of nitrogen dioxide and nitric oxide is characterized by accuracy of 25%. Presence of sulfur dioxide increases measurement error up to 50%. GKh-4 supplies satisfactory results when nitrogen oxide content ranges from 0.001 to 0.0013%. Design of a new colorimeter, Ehvdiometr-1, developed by EhNIN is evaluated. The maximum error of the instrument does not exceed 5%. It is not influenced by the presence of hydrogen, carbon monoxide or methane when their content is below 10%, or by carbon dioxide when its content is below 20%, or by sulfur dioxide when its content is below 1%. Duration of measurements amounts to about 10 min. Under operational conditions in power plants the accuracy of the Ehvdiometr-1 is 5 times higher than that of the GKh-4 colorimeter. 5 refs.

Removal and recovery of nitrogen and sulfur oxides from gaseous mixtures containing them

International Nuclear Information System (INIS)

Cooper, H.B.H.

1984-01-01

A cyclic process for removing lower valence nitrogen oxides from gaseous mixtures includes treating the mixtures with an aqueous media including alkali metal carbonate and alkali metal bicarbonate and a preoxygen oxidant to form higher valence nitrogen oxides and to capture these oxides as alkali metal salts, expecially nitrites and nitrates, in a carbonate/bicarbonate-containing product aqueous media. Highly selective recovery of nitrates in high purity and yield may then follow, as by crystallization, with the carbonate and bicarbonate alkali metal salts strongly increasing the selectivity and yield of nitrates. The product nitrites are converted to nitrates by oxidation after lowering the product aqueous media pH to below about 9. A cyclic process for removing sulfur oxides from gas mixtures includes treating these mixtures includes treating these mixtures with aqueous media including alkali metal carbonate and alkali metal bicarbonate where the ratio of alkali metal to sulfur dioxide is not less than 2. The sulfur values may be recovered from the resulting carbonate/bicarbonate/-sulfite containing product aqueous media as alkali metal sulfate or sulfite salts which are removed by crystallization from the carbonate-containing product aqueous media. As with the nitrates, the carbonate/bicarbonate system strongly increases yield of sulfate or sulfite during crystallization. Where the gas mixtures include both sulfur dioxide and lower valence nitrogen oxides, the processes for removing lower valence nitrogen oxides and sulfur dioxide may be combined into a single removal/recovery system, or may be effected in sequence

Method to reduce the nitrogen oxide content of gaseous wastes

Energy Technology Data Exchange (ETDEWEB)

Klopp, G.; Sueto, J.; Szasz, K.; Szebenyi, I.; Winkler, G.; Machacs, M.; Palmai, G.

1980-11-13

The proposed process is suited for the denitrification of waste gases from nitric acid plants. It proceeds without an additional energy source with an integrated adsorption unit which guaranties the complete recirculation of the produced nitrogen oxides and allows the regeneration of the adsorbents by the use of the energy from the oxidation of nitrous oxide to nitric oxide. The desorption is carried out by the intermediate passage of the hot gases from the oxidizer through the adsorber.

Ultrafine particles and nitrogen oxides generated by gas and electric cooking

OpenAIRE

Dennekamp, M; Howarth, S; Dick, C; Cherrie, J; Donaldson, K; Seaton, A

2001-01-01

OBJECTIVES—To measure the concentrations of particles less than 100 nm diameter and of oxides of nitrogen generated by cooking with gas and electricity, to comment on possible hazards to health in poorly ventilated kitchens.
METHODS—Experiments with gas and electric rings, grills, and ovens were used to compare different cooking procedures. Nitrogen oxides (NOx) were measured by a chemiluminescent ML9841A NOx analyser. A TSI 3934 scanning mobility particle sizer was used to measure average nu...

Study of ionic movements during anodic oxidation of nitrogen-implanted aluminium

International Nuclear Information System (INIS)

Terwagne, G.; Lucas, S.; Bodart, F.; Sorensen, G.; Jensen, H.

1990-01-01

In recent years there has been a considerable interest in synthesizing aluminium nitrides by ion implantation in order to modify the tribological properties of aluminium. The growth of an oxide layer by anodic process on these synthesized aluminium nitrides gives an interesting oxide-on-semiconductor material with surprising dynamic and decorative properties. During the anodic oxidation, ionic movements are involved in the near-surface region of the aluminium material; these ionic movements have been studied by Rutherford backscattering spectrometry (RBS) and nuclear reaction analysis (NRA) on thin aluminium foils (7000 A) preimplanted with nitrogen and post-oxidized in an ammonium pentaborate solution. The growth of the oxide layer is reduced when the aluminium is preimplanted with nitrogen: the speed of oxidation depends on the implantation conditions (energy and fluence). Moreover, the aluminium nitride can be dissolved when all metallic aluminium staying between the surface and the AlN are consumed by the anodic process. (orig.)

Year 2020: Consequences of population growth and development on deposition of oxidized nitrogen

Energy Technology Data Exchange (ETDEWEB)

Galloway, J N [Environmental Sciences Dept., Univ. of Virginia, Charlottesville, VA (United States); Levy, H; Kasibhatla, P S [NOAA Geophysical Fluid Dynamics Lab., Princeton, NJ (United States)

1994-01-01

With a current world population of 5.3 billion, fossil fuel and biomass burning have already greatly increased the emission of fixed nitrogen to the global atmosphere. In 2020, with a projected population of 8.5 billion and an assumed 100% increase in per capita energy consumption relative to 1980 by the lesser developed countries, we predict an approximate 25% increase in total nitrogen deposition in the more developed country source regions such as North America. In addition, reactive nitrogen deposition will at least double in less developed regions, such as SE Asia and Latin America, and will increase by more than 50% over the oceans of the Northern Hemisphere. Although we also predict significant increases in the deposition of nitrogen from fossil-fuel sources over most of the Southern Hemisphere, particularly Africa, the tropical eastern Pacific, and the southern Atlantic and Indian Oceans, biomass burning and the natural sources of nitrogen oxides (lightning and biogenic soil emissions) are also important in these regions. This increased deposition has the potential to fertilize both terrestrial and marine ecosystems, resulting in the sequestering of carbon. Increases in nitrogen deposition have also been shown not only to acidify ecosystems but also to increase emissions of nitric oxide (NO), nitrous oxide (N[sub 2]O), carbonyl sulfide (COS), and carbon+sulfur (CS[sub 2]) to the atmosphere and decrease methane (CH[sub 4]) consumption in forest soils. We also find that the atmospheric levels of nitrogen oxides increase significantly throughout much of the Northern Hemisphere and populated regions of the Southern Hemisphere. This increase may lead to larger ozone concentrations with resulting increases in the oxidative capacity of the remote atmosphere and its ability to absorb IR radiation. 31 refs, 3 figs, 1 tab

Year 2020: Consequences of population growth and development on deposition of oxidized nitrogen

International Nuclear Information System (INIS)

Galloway, J.N.; Levy, H.; Kasibhatla, P.S.

1994-01-01

With a current world population of 5.3 billion, fossil fuel and biomass burning have already greatly increased the emission of fixed nitrogen to the global atmosphere. In 2020, with a projected population of 8.5 billion and an assumed 100% increase in per capita energy consumption relative to 1980 by the lesser developed countries, we predict an approximate 25% increase in total nitrogen deposition in the more developed country source regions such as North America. In addition, reactive nitrogen deposition will at least double in less developed regions, such as SE Asia and Latin America, and will increase by more than 50% over the oceans of the Northern Hemisphere. Although we also predict significant increases in the deposition of nitrogen from fossil-fuel sources over most of the Southern Hemisphere, particularly Africa, the tropical eastern Pacific, and the southern Atlantic and Indian Oceans, biomass burning and the natural sources of nitrogen oxides (lightning and biogenic soil emissions) are also important in these regions. This increased deposition has the potential to fertilize both terrestrial and marine ecosystems, resulting in the sequestering of carbon. Increases in nitrogen deposition have also been shown not only to acidify ecosystems but also to increase emissions of nitric oxide (NO), nitrous oxide (N 2 O), carbonyl sulfide (COS), and carbon+sulfur (CS 2 ) to the atmosphere and decrease methane (CH 4 ) consumption in forest soils. We also find that the atmospheric levels of nitrogen oxides increase significantly throughout much of the Northern Hemisphere and populated regions of the Southern Hemisphere. This increase may lead to larger ozone concentrations with resulting increases in the oxidative capacity of the remote atmosphere and its ability to absorb IR radiation. 31 refs, 3 figs, 1 tab

40 CFR Appendix S to Part 50 - Interpretation of the Primary National Ambient Air Quality Standards for Oxides of Nitrogen...

Science.gov (United States)

2010-07-01

... Ambient Air Quality Standards for Oxides of Nitrogen (Nitrogen Dioxide) S Appendix S to Part 50 Protection... National Ambient Air Quality Standards for Oxides of Nitrogen (Nitrogen Dioxide) 1. General (a) This... national ambient air quality standards for oxides of nitrogen as measured by nitrogen dioxide (“NO2 NAAQS...

Decorating Mg/Fe oxide nanotubes with nitrogen-doped carbon nanotubes

Energy Technology Data Exchange (ETDEWEB)

Cao Yong, E-mail: caoyangel@126.com [Institute of Environment and Municipal Engineering, North China Institute of Water Conservancy and Hydroelectric Power, Zhengzhou 450011 (China); Jiao Qingze, E-mail: jiaoqz@bit.edu.cn [School of Chemical Engineering and the Environment, Beijing Institute of Technology, Beijing 100081 (China); Zhao Yun [School of Chemical Engineering and the Environment, Beijing Institute of Technology, Beijing 100081 (China); Dong Yingchao [Materials and Surface Science Institute (MSSI), University of Limerick, Limerick (Ireland)

2011-09-22

Graphical abstract: Highlights: > Mg/Fe oxide nanotubes arrayed parallel to each other were prepared by an AAO template method. > The Mg/Fe oxide nanotubes decorated with CN{sub x} were realized by CVD of ethylenediamine on the outer surface of oxide nanotubes. > The magnetic properties of Mg/Fe oxide nanotubes were highly improved after being decorated. - Abstract: Mg/Fe oxide nanotubes decorated with nitrogen-doped carbon nanotubes (CN{sub x}) were fabricated by catalytic chemical vapor deposition of ethylenediamine on the outer surface of oxide nanotubes. Mg/Fe oxide nanotubes were prepared using a 3:1 molar precursor solution of Mg(NO{sub 3}){sub 2} and Fe(NO{sub 3}){sub 3} and anodic aluminum oxide as the substrate. The obtained samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and vibrating sample magnetometer (VSM). The XRD pattern shows that the oxide nanotubes are made up of MgO and Fe{sub 2}O{sub 3}. TEM and SEM observations indicate the oxide nanotubes are arrayed roughly parallel to each other, and the outer surface of oxide nanotubes are decorated with CN{sub x}. XPS results show the nitrogen-doped level in CN{sub x} is about 7.3 at.%. Magnetic measurements with VSM demonstrate the saturated magnetization, remanence and coercivity of oxide nanotubes are obvious improved after being decorated with CN{sub x}.

Quantifying the Global Marine Biogenic Nitrogen Oxides Emissions

Science.gov (United States)

Su, H.; Wang, S.; Lin, J.; Hao, N.; Poeschl, U.; Cheng, Y.

2017-12-01

Nitrogen oxides (NOx) are among the most important molecules in atmospheric chemistry and nitrogen cycle. The NOx over the ocean areas are traditionally believed to originate from the continental outflows or the inter-continental shipping emissions. By comparing the satellite observations (OMI) and global chemical transport model simulation (GEOS-Chem), we suggest that the underestimated modeled atmospheric NO2 columns over biogenic active ocean areas can be possibly attributed to the biogenic source. Nitrification and denitrification in the ocean water produces nitrites which can be further reduced to NO through microbiological processes. We further report global distributions of marine biogenic NO emissions. The new added emissions improve the agreement between satellite observations and model simulations over large areas. Our model simulations manifest that the marine biogenic NO emissions increase the atmospheric oxidative capacity and aerosol formation rate, providing a closer link between atmospheric chemistry and ocean microbiology.

NOxTOy: A miniaturised new instrument for reactive nitrogen oxides in the atmosphere

International Nuclear Information System (INIS)

Dommen, J.; Prevot, A.S.H.; Neininger, B.; Clark, N.

2000-01-01

Emission of nitrogen oxides (NO, NO 2 ) and hydrocarbons into the atmosphere lead, under sunlight, to the formation of ozone and other photo oxidants. To better understand the ozone forming processes, the production and concentration of the nitrogen containing reaction products like nitric acid (HNO 3 ) or peroxyacetylnitrate (PAN) have to be determined. In a joint project with other research institutions and a private enterprise a miniaturised instrument was developed under a KTI contract. It is possible to measure several nitrogen oxides, NO 2 , NO x , NO y , PAN, HNO 3 and O x simultaneously. The dimensions and the power consumption of the instrument are suited for the operation in a motor glider and in a van. First measurements have been successfully performed and are presented. (authors)

[Ammonia-oxidizing archaea and their important roles in nitrogen biogeochemical cycling: a review].

Science.gov (United States)

Liu, Jing-Jing; Wu, Wei-Xiang; Ding, Ying; Shi, De-Zhi; Chen, Ying-Xu

2010-08-01

As the first step of nitrification, ammonia oxidation is the key process in global nitrogen biogeochemical cycling. So far, the autotrophic ammonia-oxidizing bacteria (AOB) in the beta- and gamma-subgroups of proteobacteria have been considered as the most important contributors to ammonia oxidation, but the recent researches indicated that ammonia-oxidizing archaea (AOA) are widely distributed in various kinds of ecosystems and quantitatively predominant, playing important roles in the global nitrogen biogeochemical cycling. This paper reviewed the morphological, physiological, and ecological characteristics and the molecular phylogenies of AOA, and compared and analyzed the differences and similarities of the ammonia monooxygenase (AMO) and its encoding genes between AOA and AOB. In addition, the potential significant roles of AOA in nitrogen biogeochemical cycling in aquatic and terrestrial ecosystems were summarized, and the future research directions of AOA in applied ecology and environmental protection were put forward.

Methanol electrocatalytic oxidation on Pt nanoparticles on nitrogen doped graphene prepared by the hydrothermal reaction of graphene oxide with urea

International Nuclear Information System (INIS)

Xu, Xiao; Zhou, Yingke; Yuan, Tao; Li, Yawei

2013-01-01

A facile hydrothermal reaction of graphene oxide with urea was used to produce nitrogen doped graphene, and Pt nanoparticles were deposited on the obtained nitrogen doped graphene by the NaBH 4 reduction route. The morphology and microstructure of the synthesized catalysts were characterized by transmission electron microscopy, X-ray powder diffraction and X-ray photoelectron spectroscopy, while the functional groups on the surface of the catalysts were investigated by the Fourier transform infrared spectroscopy and ultraviolet-visible absorption spectra. Cyclic voltammetry, chronoamperometry and electrochemical impedance techniques were carried out to evaluate the methanol electrocatalytic oxidation activity and durability of Pt catalysts supported on the nitrogen doped graphene. The results showed that nitrogen doping and reduction of GO were achieved simultaneously by the facile hydrothermal reaction, which had beneficial effects for the deposition process and electrocatalytic activity of Pt nanoparticles. The Pt catalysts supported on the nitrogen doped graphene substrate presented excellent activity and durability of methanol oxidation reaction, which might be promising for application in direct methanol fuel cells

Molecular nitrogen fixation and nitrogen cycle in nature

Energy Technology Data Exchange (ETDEWEB)

Virtanen, A I

1952-01-01

The origin of nitrogen oxides in the atmosphere is discussed. Evidently only a small proportion of the nitrate-and nitrite-nitrogen found in the precipitation is formed through electric discharges from molecular nitrogen, photochemical nitrogen fixation being probably of greater importance. Formation of nitrate nitrogen through atmospheric oxidation of nitrous oxide (N/sub 2/O) evaporating from the soil is also considered likely. Determination of nitrogen compounds at different altitudes is indispensable for gaining information of the N/sub 2/-fixation in the atmosphere and, in general, of the origin of nitrogen oxides and their decomposition. International cooperation is needed for this as well as for the quantitative determination of the nitrogen compounds removed from the soil by leaching and brought by waters into the seas.

Reduction of Nitrogen Oxides Emissions from a Coal-Fired Boiler Unit

Science.gov (United States)

Zhuikov, Andrey V.; Feoktistov, Dmitry V.; Koshurnikova, Natalya N.; Zlenko, Lyudmila V.

2016-02-01

During combustion of fossil fuels a large amount of harmful substances are discharged into the atmospheres of cities by industrial heating boiler houses. The most harmful substances among them are nitrogen oxides. The paper presents one of the most effective technological solutions for suppressing nitrogen oxides; it is arrangement of circulation process with additional mounting of the nozzle directed into the bottom of the ash hopper. When brown high-moisture coals are burnt in the medium power boilers, generally fuel nitrogen oxides are produced. It is possible to reduce their production by two ways: lowering the temperature in the core of the torch or decreasing the excess-air factor in the boiler furnace. Proposed solution includes the arrangement of burning process with additional nozzle installed in the lower part of the ash hopper. Air supply from these nozzles creates vortex involving large unburned fuel particles in multiple circulations. Thereby time of their staying in the combustion zone is prolonging. The findings describe the results of the proposed solution; and recommendations for the use of this technological method are given for other boilers.

40 CFR 60.4320 - What emission limits must I meet for nitrogen oxides (NOX)?

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 6 2010-07-01 2010-07-01 false What emission limits must I meet for nitrogen oxides (NOX)? 60.4320 Section 60.4320 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... nitrogen oxides (NOX)? (a) You must meet the emission limits for NOX specified in Table 1 to this subpart...

Application of a Chemiluminescence Detector for the Measurement of Total Oxides of Nitrogen and Ammonia in the Atmosphere

Science.gov (United States)

Hodgeson, J. A.; Bell, J. P.; Rehme, K. A.; Krost, K. J.; Stevens, R. K.

1971-01-01

By means of the thermal conversion of nitrogen dioxide to the nitric oxide, the chemiluminescent nitric oxide monitor, based on the nitric oxide plus ozone reaction, may be used for monitoring nitrogen dioxide plus nitric oxide (NO(x)). Under conditions previously described, ammonia is also converted to nitric oxide and therefore interferes. A metal surface, gold wool or stainless steel, operated at two different temperatures has been used to convert only nitrogen dioxide or nitrogen dioxide plus ammonia. Quantitative conversion of nitrogen dioxide to nitric oxide has been obtained at temperatures as low as 200 C. Conversion of ammonia is effected at temperatures of 300 C or higher. By the addition of a converter the basic nitric oxide monitor may be used for measuring NO(x) or NO(x) plus ammonia. As an alternate mode, for a fixed high temperature, a specific scrubber is described for removing NH3 without affecting NO2 concentrations.

Oxides of nitrogen and the clouds of Venus

International Nuclear Information System (INIS)

Watson, A.J.; Donahue, T.M.; Stedman, D.H.; Knollenberg, R.G.; Ragent, B.; Blamont, J.

1979-01-01

Nitric Oxide may be produced in the atmosphere of Venus by lightning storms in the clouds. Here we suggest that the odd nitrogen thus formed may play an important part in the chemistry of the clouds. Specifically, we estimate production rates for NO 2 in the limiting case of high NO concentrations. If the NO density is high we suggest that NO 2 may catalyse the production of sulfuric acid aerosol from sulfur dioxide and water vapor, and may also form nitrogen--sulfur compounds such as nitrosyl sulfuric acid, NOHSO 4 . The ''large particles'' seen by the Pioneer Venus sounder probe may contain considerable quantities of NOHSO 4 . If this is the case odd nitrogen must be present in the atmosphere in at least a parts-per-million mixing ratio

How exogenous nitric oxide regulates nitrogen assimilation in wheat seedlings under different nitrogen sources and levels.

Science.gov (United States)

Balotf, Sadegh; Islam, Shahidul; Kavoosi, Gholamreza; Kholdebarin, Bahman; Juhasz, Angela; Ma, Wujun

2018-01-01

Nitrogen (N) is one of the most important nutrients for plants and nitric oxide (NO) as a signaling plant growth regulator involved in nitrogen assimilation. Understanding the influence of exogenous NO on nitrogen metabolism at the gene expression and enzyme activity levels under different sources of nitrogen is vitally important for increasing nitrogen use efficiency (NUE). This study investigated the expression of key genes and enzymes in relation to nitrogen assimilation in two Australian wheat cultivars, a popular high NUE cv. Spitfire and a normal NUE cv. Westonia, under different combinations of nitrogen and sodium nitroprusside (SNP) as the NO donor. Application of NO increased the gene expressions and activities of nitrogen assimilation pathway enzymes in both cultivars at low levels of nitrogen. At high nitrogen supplies, the expressions and activities of N assimilation genes increased in response to exogenous NO only in cv. Spitfire but not in cv. Westonia. Exogenous NO caused an increase in leaf NO content at low N supplies in both cultivars, while under high nitrogen treatments, cv. Spitfire showed an increase under ammonium nitrate (NH4NO3) treatment but cv. Westonia was not affected. N assimilation gene expression and enzyme activity showed a clear relationship between exogenous NO, N concentration and N forms in primary plant nitrogen assimilation. Results reveal the possible role of NO and different nitrogen sources on nitrogen assimilation in Triticum aestivum plants.

[Bacterial anaerobic ammonia oxidation (Anammox) in the marine nitrogen cycle--a review].

Science.gov (United States)

Hong, Yiguo; Li, Meng; Gu, Jidong

2009-03-01

Anaerobic ammonium oxidation (Anammox) is a microbial oxidation process of ammonium, with nitrite as the electron acceptor and dinitrogen gas as the main product, and is performed by a clade of deeply branched Planctomycetes, which possess an intracytoplasmic membrane-bounded organelle, the anammoxosome, for the Anammox process. The wide distribution of Anammox bacteria in different natural environments has been greatly modified the traditional view of biogeochemical cycling of nitrogen, in which microbial denitrifier is considered as the only organism to respire nitrate and nitrite to produce nitric and nitrous oxides, and eventually nitrogen gas. More evidences indicate that Anammox is responsible for the production of more than 50% of oceanic N2 and plays an important role in global nitrogen cycling. Moreover, due to the close relationship between nitrogen and carbon cycling, it is anticipated that Anammox process might also affect the concentration of CO2 in the atmosphere, and influence the global climate change. In addition, the simultaneous transformation of nitrite and ammonium in wastewater treatment by Anammox would allow a 90% reduction in operational costs and provide a much more effective biotechnological process for wastewater treatment.

Reaction Mechanism for the Formation of Nitrogen Oxides (NO x ) During Coke Oxidation in Fluidized Catalytic Cracking Units

KAUST Repository

Chaparala, Sree Vidya

2015-06-11

Fluidized catalytic cracking (FCC) units in refineries process heavy feedstock obtained from crude oil distillation. While cracking feed, catalysts get deactivated due to coke deposition. During catalyst regeneration by burning coke in air, nitrogen oxides (NOx) are formed. The increase in nitrogen content in feed over time has resulted in increased NOx emissions. To predict NOx concentration in flue gas, a reliable model for FCC regenerators is needed that requires comprehensive understanding and accurate kinetics for NOx formation. Based on the nitrogen-containing functional groups on coke, model molecules are selected to study reactions between coke-bound nitrogen and O2 to form NO and NO2 using density functional theory. The reaction kinetics for the proposed pathways are evaluated using transition state theory. It is observed that the addition of O2 on coke is favored only when the free radical is present on the carbon atom instead of nitrogen atom. Thus, NOx formation during coke oxidation does not result from the direct attack by O2 on N atoms of coke, but from the transfer of an O atom to N from a neighboring site. The low activation energies required for NO formation indicate that it is more likely to form than NO2 during coke oxidation. The favorable pathways for NOx formation that can be used in FCC models are identified. Copyright © 2015 Taylor & Francis Group, LLC.

Fractal and variability analysis of simulations in ozone level due to oxides of nitrogen and sulphur

Science.gov (United States)

Bhardwaj, Rashmi; Pruthi, Dimple

2017-10-01

Air pollution refers to the release of pollutants into the air. These pollutants are detrimental to human the planet as a whole. Apart from causing respiratory infections and pulmonary disorders, rising levels of Nitrogen Dioxide is worsening ozone pollution. Formation of Ground-level ozone involves nitrogen oxides and volatile gases in the sunlight. Volatile gases are emitted from vehicles primarily. Ozone is harmful gas and its exposure can trigger serious health effects as it damages lung tissues. In order to decrease the level of ozone, level of oxides leading to ozone formation has to be dealt with. This paper deals with the simulations in ozone due to oxides of nitrogen and sulphur. The data from Central Pollution Control Board shows positive correlation for ozone with oxides of sulphur and nitrogen for RK Puram, Delhi in India where high concentration of ozone has been found. The correlation between ozone and sulphur, nitrogen oxides is moderate during summer while weak during winters. Ozone with nitrogen and sulphur dioxide follow persistent behavior as Hurst exponent is between 0.5 and 1. The fractal dimension for Sulphur dioxide is 1.4957 indicating the Brownian motion. The behavior of ozone is unpredictable as index of predictability is close to zero.

Absorption and oxidation of nitrogen oxide in ionic liquids

DEFF Research Database (Denmark)

Kunov-Kruse, Andreas Jonas; Thomassen, Peter Langelund; Riisager, Anders

2016-01-01

A new strategy for capturing nitrogen oxide, NO, from the gas phase is presented. Dilute NO gas is removed from the gas phase by ionic liquids under ambient conditions. The nitrate anion of the ionic liquid catalyzes the oxidation of NO to nitric acid by atmospheric oxygen in the presence of water....... The nitric acid is absorbed in the ionic liquid up to approximately one mole HNO3 per mole of the ionic liquid due to the formation of hydrogen bonds. The nitric acid can be desorbed by heating, thereby regenerating the ionic liquid with excellent reproducibility. Here, time-resolved in-situ spectroscopic...... investigations of the reaction and products are presented. The procedure reveals a new vision for removing the pollutant NO by absorption into a non-volatile liquid and converting it into a useful bulk chemical, that is, HNO3....

Nitrogen Oxide Fluxes and Nitrogen Cycling during Postagricultural Succession and Forest Fertilization in the Humid Tropics.

Science.gov (United States)

Heather Erickson; Michael Keller; Eric Davidson

2001-01-01

The effects of changes in tropical land use on soil emissions of nitrous oxide (N2O) and nitric oxide (NO) are not well understood. We examined emissions of N2O and NO and their relationships to land use and forest composition, litterfall, soil nitrogen (N) pools and turnover, soil moisture, and patterns of carbon (C) cycling in a lower montane, subtropical wet region...

Onset of the aerobic nitrogen cycle during the Great Oxidation Event.

Science.gov (United States)

Zerkle, Aubrey L; Poulton, Simon W; Newton, Robert J; Mettam, Colin; Claire, Mark W; Bekker, Andrey; Junium, Christopher K

2017-02-23

The rise of oxygen on the early Earth (about 2.4 billion years ago) caused a reorganization of marine nutrient cycles, including that of nitrogen, which is important for controlling global primary productivity. However, current geochemical records lack the temporal resolution to address the nature and timing of the biogeochemical response to oxygenation directly. Here we couple records of ocean redox chemistry with nitrogen isotope ( 15 N/ 14 N) values from approximately 2.31-billion-year-old shales of the Rooihoogte and Timeball Hill formations in South Africa, deposited during the early stages of the first rise in atmospheric oxygen on the Earth (the Great Oxidation Event). Our data fill a gap of about 400 million years in the temporal 15 N/ 14 N record and provide evidence for the emergence of a pervasive aerobic marine nitrogen cycle. The interpretation of our nitrogen isotope data in the context of iron speciation and carbon isotope data suggests biogeochemical cycling across a dynamic redox boundary, with primary productivity fuelled by chemoautotrophic production and a nitrogen cycle dominated by nitrogen loss processes using newly available marine oxidants. This chemostratigraphic trend constrains the onset of widespread nitrate availability associated with ocean oxygenation. The rise of marine nitrate could have allowed for the rapid diversification and proliferation of nitrate-using cyanobacteria and, potentially, eukaryotic phytoplankton.

Inhibition of apparent photosynthesis by nitrogen oxides

Energy Technology Data Exchange (ETDEWEB)

Hill, A C; Bennett, J H

1970-01-01

The nitrogen oxides (NO/sub 2/ and NO) inhibited apparent photosynthesis of oats and alfalfa at concentrations below those required to cause visible injury. There appeared to be a threshold concentration of about 0.6 ppm for each pollutant. An additive effect in depressing apparent photosynthesis occurred when the plants were exposed to a mixture of NO and NO/sub 2/. Although NO produced a more rapid effect on the plants, lower concentrations of NO/sub 2/ were required to cause a given inhibition after 2 hour of exposure. Inhibition by nitric oxide was more closely related to its partial pressure than was inhibition by NO/sub 2/.

Nitrogen Doped Ordered Mesoporous Carbon as Support of PtRu Nanoparticles for Methanol Electro-Oxidation

Directory of Open Access Journals (Sweden)

David Sebastián

2018-04-01

Full Text Available The low oxidation kinetics of alcohols and the need for expensive platinum group metals are still some of the main drawbacks for the commercialization of energy efficient direct alcohol fuel cells. In this work, we investigate the influence of nitrogen doping of ordered mesoporous carbon (CMK as support on the electrochemical activity of PtRu nanoparticles. Nitrogen doping procedures involve the utilization of pyrrole as both nitrogen and carbon precursor by means of a templating method using mesoporous silica. This method allows obtaining carbon supports with up to 14 wt. % nitrogen, with an effective introduction of pyridinic, pyrrolic and quaternary nitrogen. PtRu nanoparticles were deposited by sodium formate reduction method. The presence of nitrogen mainly influences the Pt:Ru atomic ratio at the near surface, passing from 50:50 on the bare (un-doped CMK to 70:30 for the N-doped CMK catalyst. The electroactivity towards the methanol oxidation reaction (MOR was evaluated in acid and alkaline electrolytes. The presence of nitrogen in the support favors a faster oxidation of methanol due to the enrichment of Pt at the near surface together with an increase of the intrinsic activity of PtRu nanoparticles.

Nitrogen oxides from combustion of nitrogen-containing polymers in waste-derived fuels

International Nuclear Information System (INIS)

Zevenhoven, R.; Kilpinen, P.; Hupa, M.; Elomaa, M.

2000-01-01

Usually, waste-derived fuels present nitrogen-containing fractions, which produce nitrogen oxides (NO) during combustion. This study was mainly concerned with poly amides (PA) (nylon), poly urethanes (PU), urea formaldehyde (UF) glue, sewage sludge and refuse-derived fuels (RDF). For control purposes, the authors chose a Polish sub-bituminous coal and a Finnish pine wood sample. An almost inverse trend between fuel nitrogen content and NO emissions was revealed through analysis of NO emissions at 850 Celsius, 1 bar, 7 per cent O 2 in N 2 . It was not possible to derive a clear correlation to the amount of ash generated by the samples. PU foam decomposed through a two-step process, as suggested by thermochromatography, and PA6-containing samples yielded epsilon-caprolactam as a major decomposition product. Important decomposition products from PU, PA6, PA6/PE, sewage sludge and UF glue samples were greenhouse gases as demonstrated by pyrolysis-gas chromatography/mass spectroscopy. The work was carried out at Abo Akademi University and University of Helsinki, Finland. 5 refs., 2 tabs., 3 figs

Nitrogen oxides storage catalysts containing cobalt

Science.gov (United States)

Lauterbach, Jochen; Snively, Christopher M.; Vijay, Rohit; Hendershot, Reed; Feist, Ben

2010-10-12

Nitrogen oxides (NO.sub.x) storage catalysts comprising cobalt and barium with a lean NO.sub.x storage ratio of 1.3 or greater. The NO.sub.x storage catalysts can be used to reduce NO.sub.x emissions from diesel or gas combustion engines by contacting the catalysts with the exhaust gas from the engines. The NO.sub.x storage catalysts can be one of the active components of a catalytic converter, which is used to treat exhaust gas from such engines.

Studies on nitrogen oxides (NOx and N2O) in pressurized fluidized bed combustion

International Nuclear Information System (INIS)

Lu Yong

1998-01-01

This thesis describes the experimental studies of nitrogen oxide (NO, NO 2 , N 2 O) emissions in pressurized fluidized bed combustion (PFBC). In the first part of the thesis the background and the objectives of this study are introduced. The second part summarizes the fundamental knowledge about the formation and destruction of nitrogen oxides in coal combustion, particularly in the conditions of PFBC. The instrumentation of test facilities, measurement and data analysis is described in the third part. Then the most important experimental results follow in the next parts. The forth part describes the results from a PFBC test rig and an empirical modelling for predicting the emissions of NO x and N 2 O. Finally, the fundamental work on coal combustion and fuel nitrogen conversion in a PFBC batch reactor is presented. These studies clearly confirm the potential of PFBC technology in the control nitrogen of oxide emissions. The research in the test rig was concentrated on determining the effects of process parameters on the emissions of nitrogen oxides with different fuels. Another objective was to examine the reduction of nitrogen oxides with the control methods in PFBC conditions, including ammonia injection and air staging combustion for reducing NO, and high temperature operations for reducing N 2 0. The results indicate that pressurized operation suppresses the conversion of fuel-N to nitrogen oxides and favors with employing the reduction methods for further nitrogen oxide reduction, for instance the temperature window of NO reduction with ammonia injection has been found to be widened to even lower temperature range. Maximum reductions of 80-85 % with ammonia injection and 75-80 % with air staging combustion were achieved in the conditions examined. Considerably low emissions of N 2 O ( 2 O control, and thermal decomposition proved to be the laming pathway of N 2 O destruction in PFBC. In the examined pressure range, increasing pressure causes a decrease of NO

Analysis of alternative pathways for reducing nitrogen oxide emissions

Science.gov (United States)

Strategies for reducing tropospheric ozone typically include modifying combustion processes to reduce the formation of nitrogen oxides (NOx) and applying control devices that remove NOx from the exhaust gases of power plants, industrial sources and vehicles. For portions of the ...

Influence of carbon dioxide content in the biogas to nitrogen oxides emissions

Directory of Open Access Journals (Sweden)

Živković Marija A.

2010-01-01

Full Text Available Fuels derived from biomass are an alternative solution for the fossil fuel shortage. Usually this kind of fuels is called low calorific value fuels, due to the large proportion of inert components in their composition. The most common is carbon dioxide, and its proportion in biogas can be different, from 10 up to 40%, or even more. The presence of inert component in the composition of biogas causes the problems that are related with flame blow off limits. One of the possibilities for efficient combustion of biogas is the combustion in swirling flow including a pilot burner, aimed to expand the borders of stable combustion. This paper presents an analysis of the influence of the carbon dioxide content to the nitrogen oxides emissions. Laboratory biogas was used with different content of CO2 (10, 20, 30 and 40%. Investigation was carried out for different nominal powers, coefficients of excess air and carbon dioxide content. With increasing content of carbon dioxide, emission of nitrogen oxides was reduced, and this trend was the same throughout the whole range of excess air, carried out through measurements. Still, the influence of carbon dioxide content is significantly less than the influence of excess air. The coefficient of excess air greatly affects the production of radicals which are essential for the formation of nitrogen oxides, O, OH and CH. Also, the results show that the nominal power has no impact on the emission of nitrogen oxides.

Effect of nitrogen doping on wetting and photoactive properties of laser processed zinc oxide-graphene oxide nanocomposite layers

Energy Technology Data Exchange (ETDEWEB)

György, E., E-mail: egyorgy@icmab.es [Consejo Superior de Investigaciones Cientificas, Instituto de Ciencia de Materiales de Barcelona (CSIC-ICMAB), Campus UAB, 08193 Bellaterra (Spain); National Institute for Lasers, Plasma and Radiation Physics, P. O. Box MG 36, 76900 Bucharest V (Romania); Pérez del Pino, A. [Consejo Superior de Investigaciones Cientificas, Instituto de Ciencia de Materiales de Barcelona (CSIC-ICMAB), Campus UAB, 08193 Bellaterra (Spain); Logofatu, C. [National Institute for Materials Physics, P. O. Box MG. 7, 77125 Bucharest (Romania); Duta, A.; Isac, L. [Transilvania University of Brasov, Research Centre for Renewable Energy Systems and Recycling, Eroilor 29, 500036, Brasov (Romania)

2014-07-14

Zinc oxide-graphene oxide nanocomposite layers were submitted to laser irradiation in air or controlled nitrogen atmosphere using a frequency quadrupled Nd:YAG (λ = 266 nm, τ{sub FWHM} ≅ 3 ns, ν = 10 Hz) laser source. The experiments were performed in air at atmospheric pressure or in nitrogen at a pressure of 2 × 10{sup 4} Pa. The effect of the irradiation conditions, incident laser fluence value, and number of subsequent laser pulses on the surface morphology of the composite material was systematically investigated. The obtained results reveal that nitrogen incorporation improves significantly the wetting and photoactive properties of the laser processed layers. The kinetics of water contact angle variation when the samples are submitted to laser irradiation in nitrogen are faster than that of the samples irradiated in air, the surfaces becoming super-hydrophilic under UV light irradiation.

Reduction of Nitrogen Oxides Emissions from a Coal-Fired Boiler Unit

Directory of Open Access Journals (Sweden)

Zhuikov Andrey V.

2016-01-01

Full Text Available During combustion of fossil fuels a large amount of harmful substances are discharged into the atmospheres of cities by industrial heating boiler houses. The most harmful substances among them are nitrogen oxides. The paper presents one of the most effective technological solutions for suppressing nitrogen oxides; it is arrangement of circulation process with additional mounting of the nozzle directed into the bottom of the ash hopper. When brown high-moisture coals are burnt in the medium power boilers, generally fuel nitrogen oxides are produced. It is possible to reduce their production by two ways: lowering the temperature in the core of the torch or decreasing the excess-air factor in the boiler furnace. Proposed solution includes the arrangement of burning process with additional nozzle installed in the lower part of the ash hopper. Air supply from these nozzles creates vortex involving large unburned fuel particles in multiple circulations. Thereby time of their staying in the combustion zone is prolonging. The findings describe the results of the proposed solution; and recommendations for the use of this technological method are given for other boilers.

Nitrogen and Oxygen Isotope Effects of Ammonia Oxidation by Thermophilic Thaumarchaeota from a Geothermal Water Stream.

Science.gov (United States)

Nishizawa, Manabu; Sakai, Sanae; Konno, Uta; Nakahara, Nozomi; Takaki, Yoshihiro; Saito, Yumi; Imachi, Hiroyuki; Tasumi, Eiji; Makabe, Akiko; Koba, Keisuke; Takai, Ken

2016-08-01

Ammonia oxidation regulates the balance of reduced and oxidized nitrogen pools in nature. Although ammonia-oxidizing archaea have been recently recognized to often outnumber ammonia-oxidizing bacteria in various environments, the contribution of ammonia-oxidizing archaea is still uncertain due to difficulties in the in situ quantification of ammonia oxidation activity. Nitrogen and oxygen isotope ratios of nitrite (δ(15)NNO2- and δ(18)ONO2-, respectively) are geochemical tracers for evaluating the sources and the in situ rate of nitrite turnover determined from the activities of nitrification and denitrification; however, the isotope ratios of nitrite from archaeal ammonia oxidation have been characterized only for a few marine species. We first report the isotope effects of ammonia oxidation at 70°C by thermophilic Thaumarchaeota populations composed almost entirely of "Candidatus Nitrosocaldus." The nitrogen isotope effect of ammonia oxidation varied with ambient pH (25‰ to 32‰) and strongly suggests the oxidation of ammonia, not ammonium. The δ(18)O value of nitrite produced from ammonia oxidation varied with the δ(18)O value of water in the medium but was lower than the isotopic equilibrium value in water. Because experiments have shown that the half-life of abiotic oxygen isotope exchange between nitrite and water is longer than 33 h at 70°C and pH ≥6.6, the rate of ammonia oxidation by thermophilic Thaumarchaeota could be estimated using δ(18)ONO2- in geothermal environments, where the biological nitrite turnover is likely faster than 33 h. This study extended the range of application of nitrite isotopes as a geochemical clock of the ammonia oxidation activity to high-temperature environments. Because ammonia oxidation is generally the rate-limiting step in nitrification that regulates the balance of reduced and oxidized nitrogen pools in nature, it is important to understand the biological and environmental factors underlying the regulation of

Anodic ammonia oxidation to nitrogen gas catalyzed by mixed biofilms in bioelectrochemical systems

International Nuclear Information System (INIS)

Zhan, Guoqiang; Zhang, Lixia; Tao, Yong; Wang, Yujian; Zhu, Xiaoyu; Li, Daping

2014-01-01

In this paper we report ammonia oxidation to nitrogen gas using microbes as biocatalyst on the anode, with polarized electrode (+600 mV vs. Ag/AgCl) as electron acceptor. In batch experiments, the maximal rate of ammonia-N oxidation by the mixed culture was ∼ 60 mg L −1 d −1 , and nitrogen gas was the main products in anode compartment. Cyclic voltammetry for testing the electroactivity of the anodic biofilms revealed that an oxidation peak appeared at +600 mV (vs. Ag/AgCl), whereas the electrode without biofilms didn’t appear oxidation peak, indicating that the bioanode had good electroactivities for ammonia oxidation. Microbial community analysis of 16S rRNA genes based on high throughput sequencing indicated that the combination of the dominant genera of Nitrosomonas, Comamonas and Paracocus could be important for the electron transfer from ammonia oxidation to anode

Analyzing nitrogen concentration using carrier illumination (CI) technology for DPN ultra-thin gate oxide

International Nuclear Information System (INIS)

Li, W.S.; Wu, Bill; Fan, Aki; Kuo, C.W.; Segovia, M.; Kek, H.A.

2005-01-01

Nitrogen concentration in the gate oxide plays a key role for 90 nm and below ULSI technology. Techniques like secondary ionization mass spectroscopy (SIMS) and X-ray photoelectron spectroscopy (XPS) are commonly used for understanding N concentration. This paper describes the application of the carrier illuminationTM (CI) technique to measure the nitrogen concentration in ultra-thin gate oxides. A set of ultra-thin gate oxide wafers with different DPN (decoupled plasma nitridation) treatment conditions were measured using the CI technique. The CI signal has excellent correlation with the N concentration as measured by XPS

Removal of nitrogen compounds from Brazilian petroleum samples by oxidation followed by liquid-liquid extraction

Energy Technology Data Exchange (ETDEWEB)

Conceicao, L.; Pergher, S.B.C. [Universidade Regional Integrada do Alto Uruguai e das Misses (URI), Erechim, RS (Brazil). Dept. de Quimica], E-mail: pergher@uricer.edu.br; Oliveira, J.V. [Universidade Regional Integrada do Alto Uruguai e das Misses (URI), Erechim, RS (Brazil). Dept. de Engenharia dos Alimentos; Souza, W.F. [Petroleo Brasileiro S.A. (CENPES/PETROBRAS), Rio de Janeiro, RJ (Brazil). Centro de Pesquisas

2009-10-15

This work reports liquid-liquid extraction of nitrogen compounds from oxidized and non-oxidized Brazilian petroleum samples. The experiments were accomplished in a laboratory-scale liquid-liquid apparatus in the temperature range of 303 K-323 K, using methanol, n-methyl-2-pyrrolidone (NMP) and N,Ndimethylformamide (DMF), and their mixtures as extraction solvents, employing solvent to sample volume ratios of 1:2, 1:1 and 2:1, exploring up to three separation stages. Results show that an increase in temperature, solvent to oil ratio, and number of equilibrium stages greatly improves the nitrogen removal from the oxidized sample (from 2600 to 200 ppm). The employed oxidation scheme is thus demonstrated to be an essential and efficient step of sample preparation for the selective liquid-liquid removal of nitrogen compounds. It is shown that the use of mixtures of DMF and NMP as well their use as co-solvents with methanol did not prove to be useful for selective nitrogen extraction since great oil losses were observed in the final process. (author)

Nitrogen Doped Graphene Supported Pt Nanoflowers as Electrocatalysts for Oxidation of Formaldehyde.

Science.gov (United States)

Xie, Aijuan; Zhou, Wenting; Luo, Shiping; Chen, Yu; Zhou, Xiaoqing; Chao, Yao

2017-02-01

A facile Pt nanoflowers/nitrogen-doped graphene (PtNFs/NG) electrocatalyst was prepared via depositing Pt nanoflowers (PtNFs) onto the nitrogen-doped graphene (NG) matrix with urea as the nitrogen source and PtNFs/NG modified glassy carbon electrode (GCE) was prepared by electro-chemical method. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Raman spectroscope, X-ray photoelectron spectroscopy (XPS) and Scanning electron microscope (SEM) were used to characterize the resulting composites. Also oxidation of formaldehyde on the resulting PtNFs/NG modified electrode was investigated. The influence of deposition time, electrodeposition potential and formaldehyde concentration on electrooxidation of formaldehyde was detected, the experimental results indicate the high performance of PtNFs/NG catalyst for formaldehyde oxidation is at electrodeposition time of 300 s with the applied potential of −0.3 V. Electrochemical process, electrocatalytic stability and chronoamperometry were also inspected, it was indicated that formalde-hyde oxidation reaction on the PtNFs/NG electrode is diffusion-controlled and PtNFs/NG exhibits a high catalytic activity, stability as well as excellent poisoning-tolerance towards formaldehyde oxidation, which is attributed to the synergistic effect of PtNFs and NG. It turns out that PtNFs/NG can be used in direct liquid-feed fuel cells as a promising alternative catalyst.

Emissions of nitrogen oxides and particulates of diesel vehicles

NARCIS (Netherlands)

Kadijk, G.; Ligterink, N.E.; Mensch, P. van; Spreen, J.S.; Vermeulen, R.J.; Vonk, W.A.

2015-01-01

In real-world conditions, modern Euro VI heavy-duty vehicles produce an average of ten times less nitrogen oxide (NOx)emissions than previous generations of Euro IV and Euro V heavy-duty vehicles. However, Euro 6 passenger cars and light commercial vehicles present an entirely different picture

Determination of nitrogen in PuO2-UO2 mixed oxide with fusion-TCD method

International Nuclear Information System (INIS)

Hiyama, Toshiaki; Takahashi, Toshio; Ohuchi, Yoshiro; Suzuki, Takeshi; Kaya, Akira

1983-01-01

Nitrogen in plutonium and uranium mixed oxide has been determined by several different methods. In the classical Dumas method, nitrogen is measured volumetrically. Other procedures are modifications of the Kjeldahl method in which nitrogen is converted to ammonia. All these methods are accompanied with the same problems in which the analysis takes usually 2 or 3 days with waste solutions generated. So far, the authors have tried to determine nitrogen in PuO 2 -UO 2 mixed oxide with an improved dry process, in which an impulse furnace is used to heat the sample in a graphite crucible under a helium atmosphere. Nitrogen released from the sample were separated from other gases (i.e., a large amount of carbon monoxide, very small amount of hydrogen etc.) by a combination of original two moleculer sieve columns and pre-cut system. Separated nitrogen was then detected on the basis of thermal conductivities. (author)

Effect of nitrogen doping of graphene oxide on hydrogen and hydroxyl adsorption

Energy Technology Data Exchange (ETDEWEB)

Min, Byeong June; Jeong, Hae Kyung [Daegu University, Kyungsan (Korea, Republic of)

2014-05-15

We investigate how nitrogen-doping affects the hydrogen (H) and the hydroxyl (OH) adsorption on graphene oxide (GO) and on nitrogen-doped GO (NGO) via pseudopotential plane wave density functional calculations within the local spin density approximation. We find that the nitrogen doping brings about drastic changes in the hydrogen and the hydroxyl adsorption energetics, but its effects depend sensitively on the nitrogen configuration in NGO. The H and the OH adsorption energies are comparable only for pyrrolic NGO. In GO and quarternary NGO, the H adsorption energy is greater than the OH adsorption energy while the trend is reversed in pyridinic NGO. Also, the OH adsorption process is less affected by nitrogen-doping than the H adsorption is.

A case study of the relative effects of power plant nitrogen oxides and sulfur dioxide emission reductions on atmospheric nitrogen deposition.

Science.gov (United States)

Vijayaraghavan, Krish; Seigneur, Christian; Bronson, Rochelle; Chen, Shu-Yun; Karamchandani, Prakash; Walters, Justin T; Jansen, John J; Brandmeyer, Jo Ellen; Knipping, Eladio M

2010-03-01

The contrasting effects of point source nitrogen oxides (NOx) and sulfur dioxide (SO2) air emission reductions on regional atmospheric nitrogen deposition are analyzed for the case study of a coal-fired power plant in the southeastern United States. The effect of potential emission reductions at the plant on nitrogen deposition to Escambia Bay and its watershed on the Florida-Alabama border is simulated using the three-dimensional Eulerian Community Multiscale Air Quality (CMAQ) model. A method to quantify the relative and individual effects of NOx versus SO2 controls on nitrogen deposition using air quality modeling results obtained from the simultaneous application of NOx and SO2 emission controls is presented and discussed using the results from CMAQ simulations conducted with NOx-only and SO2-only emission reductions; the method applies only to cases in which ambient inorganic nitrate is present mostly in the gas phase; that is, in the form of gaseous nitric acid (HNO3). In such instances, the individual effects of NOx and SO2 controls on nitrogen deposition can be approximated by the effects of combined NOx + SO2 controls on the deposition of NOy, (the sum of oxidized nitrogen species) and reduced nitrogen species (NHx), respectively. The benefit of controls at the plant in terms of the decrease in nitrogen deposition to Escambia Bay and watershed is less than 6% of the overall benefit due to regional Clean Air Interstate Rule (CAIR) controls.

Dynamics of ozone and nitrogen oxides at Summit, Greenland

NARCIS (Netherlands)

Dam, Van Brie; Helmig, Detlev; Toro, Claudia; Doskey, Paul; Kramer, Louisa; Murray, Keenan; Ganzeveld, Laurens; Seok, Brian

2015-01-01

A multi-year investigation of ozone (O₃) and nitrogen oxides (NO_x) in snowpack interstitial air down to a depth of 2.8 m was conducted at Summit, Greenland, to elucidate mechanisms controlling the production and destruction of these important trace gases within the snow.

Effect of primary air content on formation of nitrogen oxides during combustion of Ehkibastuz coal

Energy Technology Data Exchange (ETDEWEB)

Kotler, V.R.; Imankulov, Eh.R.

1986-01-01

Investigations are discussed carried out in a pilot plant at the Kaz. Power Engineering Scientific Research Institute into the effect of the amount of primary air in coal-dust flame on the final concentration of nitrogen oxides in flue gases. The tests were carried out in a 7500 mm high, 1600 mm dia vertical cylindrical combustion chamber having type P-57 burner, and air dispersed fuel plus additional air supplies located at the top. Amounts of coal dust fed by a drum feeder along the air pipe varied from 100-600 kg/h. The required air was supplied by 5000 m/sup 3//h Type TK-700/5 blowers at 0.04 MPa. Ehkibastuz coal samples contained: 1.3% moisture; 48.1% ash; 38.02% carbon; 2.56% hydrogen; 0.73% sulfur; 0.60% nitrogen; heat of combustion was 14.3 MJ/kg. Results obtained indicate that variations in the amount of primary air in swirl flow burners affect formation of fuel nitrogen; there is an optimum volume at which minimum quantities of nitrogen oxides are formed. Either an increase or decrease in the primary air results in a rise in nitrogen oxide concentration. 3 references.

Preliminary assessment of air quality for sulphur dioxide, nitrogen dioxide, nitrogen oxides, particulate matter, and lead in the Netherlands under European legislation

NARCIS (Netherlands)

Breugel PB van; Buijsman E; LLO

2001-01-01

The current air quality in the Netherlands for sulphur dioxide, nitrogen dioxide, nitrogen oxides, particulate matter and lead has been assessed in the context of limit values, margins of tolerance and the assessment thresholds used in the first daughter directive for air quality of the European

Removal of nitrogen compounds from gasification gas by selective catalytic or non-catalytic oxidation; Typpiyhdisteiden poisto kaasutuskaasusta selektiivisellae katalyyttisellae ja ei-katalyyttisellae hapetuksella

Energy Technology Data Exchange (ETDEWEB)

Leppaelahti, J.; Koljonen, T. [VTT Energy, Espoo (Finland)

1996-12-01

In gasification reactive nitrogenous compounds are formed from fuel nitrogen, which may form nitrogen oxides in gas combustion. In fluidized bed gasification the most important nitrogenous compound is ammonia (NH{sub 3}). If ammonia could be decomposed to N{sub 2} already before combustion, the emissions if nitrogen oxides could be reduced significantly. One way of increasing the decomposition rate of NH{sub 3} could be the addition of suitable reactants to the gas, which would react with NH{sub 3} and produce N{sub 2}. The aim of this research is to create basic information, which can be used to develop a new method for removal of nitrogen compounds from gasification gas. The reactions of nitrogen compounds and added reactants are studied in reductive atmosphere in order to find conditions, in which nitrogen compounds can be oxidized selectively to N{sub 2}. The project consists of following subtasks: (1) Selective non-catalytic oxidation (SNCO): Reactions of nitrogen compounds and oxidizers in the gas phase, (2) Selective catalytic oxidation (SCO): Reactions of nitrogen compounds and oxidizers on catalytically active surfaces, (3) Kinetic modelling of experimental results in co-operation with the Combustion Chemistry Research Group of Aabo Akademi University. The most important finding has been that NH{sub 3} can be made to react selectively with the oxidizers even in the presence of large amounts of CO and H{sub 2}. Aluminium oxides were found to be the most effective materials promoting selectivity. (author)

Empirical yield tables for Wisconsin.

Science.gov (United States)

Jerold T. Hahn; Joan M. Stelman

1989-01-01

Describes the tables derived from the 1983 Forest Survey of Wisconsin and presents ways the tables can be used. These tables are broken down according to Wisconsin`s five Forest Survey Units and 14 forest types.

40 CFR 62.14103 - Emission limits for municipal waste combustor metals, acid gases, organics, and nitrogen oxides.

Science.gov (United States)

2010-07-01

... combustor metals, acid gases, organics, and nitrogen oxides. 62.14103 Section 62.14103 Protection of... combustor metals, acid gases, organics, and nitrogen oxides. (a) The emission limits for municipal waste combustor metals are specified in paragraphs (a)(1) through (a)(3) of this section. (1) The owner or...

Low-temperature conversion of ammonia to nitrogen in water with ozone over composite metal oxide catalyst.

Science.gov (United States)

Chen, Yunnen; Wu, Ye; Liu, Chen; Guo, Lin; Nie, Jinxia; Chen, Yu; Qiu, Tingsheng

2018-04-01

As one of the most important water pollutants, ammonia nitrogen emissions have increased year by year, which has attracted people's attention. Catalytic ozonation technology, which involves production of ·OH radical with strong oxidation ability, is widely used in the treatment of organic-containing wastewater. In this work, MgO-Co 3 O 4 composite metal oxide catalysts prepared with different fabrication conditions have been systematically evaluated and compared in the catalytic ozonation of ammonia (50mg/L) in water. In terms of high catalytic activity in ammonia decomposition and high selectivity for gaseous nitrogen, the catalyst with MgO-Co 3 O 4 molar ratio 8:2, calcined at 500°C for 3hr, was the best one among the catalysts we tested, with an ammonia nitrogen removal rate of 85.2% and gaseous nitrogen selectivity of 44.8%. In addition, the reaction mechanism of ozonation oxidative decomposition of ammonia nitrogen in water with the metal oxide catalysts was discussed. Moreover, the effect of coexisting anions on the degradation of ammonia was studied, finding that SO 4 2- and HCO 3 - could inhibit the catalytic activity while CO 3 2- and Br - could promote it. The presence of coexisting cations had very little effect on the catalytic ozonation of ammonia nitrogen. After five successive reuses, the catalyst remained stable in the catalytic ozonation of ammonia. Copyright © 2017. Published by Elsevier B.V.

Anaerobic ammonium oxidation and its contribution to nitrogen removal in China’s coastal wetlands

Science.gov (United States)

Hou, Lijun; Zheng, Yanling; Liu, Min; Li, Xiaofei; Lin, Xianbiao; Yin, Guoyu; Gao, Juan; Deng, Fengyu; Chen, Fei; Jiang, Xiaofen

2015-01-01

Over the past several decades, human activities have caused substantial enrichment of reactive nitrogen in China’s coastal wetlands. Although anaerobic ammonium oxidation (anammox), the process of oxidizing ammonium into dinitrogen gas through the reduction of nitrite, is identified as an important process for removing reactive nitrogen, little is known about the dynamics of anammox and its contribution to nitrogen removal in nitrogen-enriched environments. Here, we examine potential rates of anammox and associate them with bacterial diversity and abundance across the coastal wetlands of China using molecular and isotope tracing techniques. High anammox bacterial diversity was detected in China’s coastal wetlands and included Candidatus Scalindua, Kuenenia, Brocadia, and Jettenia. Potential anammox rates were more closely associated with the abundance of anammox bacteria than to their diversity. Among all measured environmental variables, temperature was a key environmental factor, causing a latitudinal distribution of the anammox bacterial community composition, biodiversity and activity along the coastal wetlands of China. Based on nitrogen isotope tracing experiments, anammox was estimated to account for approximately 3.8–10.7% of the total reactive nitrogen removal in the study area. Combined with denitrification, anammox can remove 20.7% of the total external terrigenous inorganic nitrogen annually transported into China’s coastal wetland ecosystems. PMID:26494435

A series of inorganic solid nitrogen sources for the synthesis of metal nitride clusterfullerenes: the dependence of production yield on the oxidation state of nitrogen and counter ion.

Science.gov (United States)

Liu, Fupin; Guan, Jian; Wei, Tao; Wang, Song; Jiao, Mingzhi; Yang, Shangfeng

2013-04-01

A series of nitrogen-containing inorganic solid compounds with variable oxidation states of nitrogen and counter ions have been successfully applied as new inorganic solid nitrogen sources toward the synthesis of Sc-based metal nitride clusterfullerenes (Sc-NCFs), including ammonium salts [(NH4)xH(3-x)PO4 (x = 0-2), (NH4)2SO4, (NH4)2CO3, NH4X (X = F, Cl), NH4SCN], thiocyanate (KSCN), nitrates (Cu(NO3)2, NaNO3), and nitrite (NaNO2). Among them, ammonium phosphates ((NH4)xH(3-x)PO4, x = 1-3) and ammonium thiocyanate (NH4SCN) are revealed to behave as better nitrogen sources than others, and the highest yield of Sc-NCFs is achieved when NH4SCN was used as a nitrogen source. The optimum molar ratio of Sc2O3:(NH4)3PO4·3H2O:C and Sc2O3:NH4SCN:C has been determined to be 1:2:15 and 1:3:15, respectively. The thermal decomposition products of these 12 inorganic compounds have been discussed in order to understand their different performances toward the synthesis of Sc-NCFs, and accordingly the dependence of the production yield of Sc-NCFs on the oxidation state of nitrogen and counter ion is interpreted. The yield of Sc3N@C80 (I(h) + D(5h)) per gram Sc2O3 by using the N2-based group of nitrogen sources (thiocyanate, nitrates, and nitrite) is overall much lower than those by using gaseous N2 and NH4SCN, indicating the strong dependence of the yield of Sc-NCFs on the oxidation state of nitrogen, which is attributed to the "in-situ" redox reaction taking place for the N2-based group of nitrogen sources during discharging. For NH3-based group of nitrogen sources (ammonium salts) which exhibits a (-3) oxidation states of nitrogen, their performance as nitrogen sources is found to be sensitively dependent on the anion, and this is understood by considering their difference on the thermal stability and/or decomposition rate. Contrarily, for the N2-based group of nitrogen sources, the formation of Sc-NCFs is independent to both the oxidation state of nitrogen (+3 or +5) and the

Nitrogen implantation of steels: A treatment which can initiate sustained oxidative wear

International Nuclear Information System (INIS)

Hale, E.B.; Reinbold, R.; Missouri Univ., Rolla; Kohser, R.A.

1987-01-01

Falex wear tests on mild (SAE 3135) steel samples treated by either nitrogen implantation (2.5x10 17 N 2 + cm -2 at 180 keV) or low temperature (about 315 0 C) oxidation are reported. The results show that both treatments lead to about an order-of-magnitude reduction in the long-term wear rate of the steel. In addition to the wear rate measurements, the wear member asymmetry behavior, scanning electron microscopy studies, Auger spectra and sputter profiles all indicate that the wear modes induced by both treatments are the same and are oxidative wear. These results confirm the previously proposed initiator-sustainer wear model in which implanted nitrogen simply acts as an initiator of favorable oxidative wear but is not directly involved in maintaining the sustained wear resistance. Possible mechanisms for both the initiation process and the sustained wear process are reviewed and discussed. (orig.)

Effects of liming and nitrogen fertilizer application on soil acidity and gaseous nitrogen oxide emissions in grassland systems

NARCIS (Netherlands)

Oenema, O.; Sapek, A.

2000-01-01

This book contains 10 articles on the EU research project COGANOG (Controlling Gaseous Nitrogen Oxide Emissions from Grassland Farming Systems in Europe). The papers present the results of studies on the effects of liming and N fertilizer application

Les oxydes d'azote dans l'environnement Nitrogen Oxides in the Environment

Directory of Open Access Journals (Sweden)

Oppeneau J. C.

2006-11-01

Full Text Available Le présent article expose les concentrations en oxydes d'azote rencontrées dans l'environnement et fait la part des origines naturelles et anthropogéniques. II présente une des manifestations les plus connues des interactions entre les oxydes d'azote, les molécules organiques, la vapeur d'eau et le rayonnement solaire le brouillard photochimique. Un certain nombre de données sur les effets d'oxydes d'azote sur l'homme et le milieu sont cités et il est mentionné que de nombreuses recherches sont à effectuer pour préciser les connaissances actuelles. Enfin, les réglementations présentes et futures sont décrites. This article describes concentrations of nitrogen oxides found in the environment and explains their natural and anthropogenic origins. It describes one of the best known examples of interactions between nitrogen oxides, organic molecules, water vaporand solorradiation, i. e. photochemical smog. Various data are brought outconcerning the effects of nitrogen oxides on man and the environment, and mention is mode of the many research projects being carried out ta specify current knowledge. Present and future regulations are also described.

Influence of implantation energy on the electrical properties of ultrathin gate oxides grown on nitrogen implanted Si substrates

International Nuclear Information System (INIS)

Kapetanakis, E.; Skarlatos, D.; Tsamis, C.; Normand, P.; Tsoukalas, D.

2003-01-01

Metal-oxide-semiconductor tunnel diodes with gate oxides, in the range of 2.5-3.5 nm, grown either on 25 or 3 keV nitrogen-implanted Si substrates at (0.3 or 1) x10 15 cm -2 dose, respectively, are investigated. The dependence of N 2 + ion implant energy on the electrical quality of the growing oxide layers is studied through capacitance, equivalent parallel conductance, and gate current measurements. Superior electrical characteristics in terms of interface state trap density, leakage current, and breakdown fields are found for oxides obtained through 3 keV nitrogen implants. These findings together with the full absence of any extended defect in the silicon substrate make the low-energy nitrogen implantation technique an attractive option for reproducible low-cost growth of nanometer-thick gate oxides

Anthropogenic emissions of oxidized sulfur and nitrogen into the atmosphere of the former Soviet Union in 1985 and 1990

Energy Technology Data Exchange (ETDEWEB)

Ryaboshapko, A.G.; Brukhanov, P.A.; Gromov, S.A.; Proshina, Yu.V; Afinogenova, O.G. [Institute of Global Climate and Ecology, Moscow (Russian Federation)

1996-09-01

Anthropogenic emissions of oxidized sulfur and nitrogen over the former Soviet Union for 1985 and 1990 were calculated on the basis of a combination of `bottom-up` and `top-down` approaches. Sulfur dioxide emissions from combustion of hard coal, brown coal, oil products, natural gas, shale oil, peat, wood as well as from metallurgy, sulfuric acid production, and cement production were estimated. Nitrogen oxides emissions were considered separately for large power plants, small power plants, industrial boilers, residential combustion units, and for transport. The sulfur and nitrogen emissions were spatially distributed over the former Soviet Union with 1 x 1 degree resolution. Data on 721 point sources of sulfur dioxide emissions and on the 242 largest power stations as nitrogen oxides sources were used. The area sources of both sulfur dioxide and nitrogen oxides were distributed according to the population density separately for about 150 administrative units of the former Soviet Union. 63 refs., 19 tabs.

Adsorption/oxidation of hydrogen sulfide on nitrogen-containing activated carbons

Energy Technology Data Exchange (ETDEWEB)

Adib, F.; Bagreev, A.; Bandosz, T.J.

2000-02-22

Wood-based activated carbon was modified by impregnation with urea and heat treatment at 450 and 950 C. The chemical and physical properties of materials were determined using acid/base titration, FTIR, thermal analysis, IGC, and sorption of nitrogen. The surface features were compared to those of a commercial urea-modified carbon. Then, the H{sub 2}S breakthrough capacity tests were carried out, and the sorption capacity was evaluated. The results showed that urea-modified sorbents have a capacity similar to that of the received material; however, the conversion of hydrogen sulfide to a water-soluble species is significantly higher. It happens due to a high dispersion of basic nitrogen compounds in the small pores of carbons, where oxidation of hydrogen sulfide ions to sulfur radicals followed by the creation of sulfur oxides and sulfuric acid occurs. It is proposed that the process proceeds gradually, from small pores to larger, and that the degree of microporosity is an important factor.

One - Step synthesis of nitrogen doped reduced graphene oxide with NiCo nanoparticles for ethanol oxidation in alkaline media.

Science.gov (United States)

Kakaei, Karim; Marzang, Kamaran

2016-01-15

Development of anode catalysts and catalyst supporting carbonaceous material containing non-precious metal have attracted tremendous attention in the field of direct ethanol fuel cells (DEFCs). Herein, we report the synthesis and electrochemical properties of nitrogen-doped reduced graphene oxide (NRGO) supported Co, Ni and NiCo nanocomposites. The metal NRGO nanocomposites, in which metal nanoparticles are embedded in the highly porous nitrogen-doped graphene matrix, have been synthesized by simply and one-pot method at a mild temperature using GO, urea choline chloride and urea as reducing and doping agent. The fabricated NiCo/NRGO exhibit remarkable electrocatalytic activity (with Tafel slope of 159.1mVdec(-1)) and high stability for the ethanol oxidation reaction (EOR). The superior performance of the alloy based NRGO is attributed to high surface area, well uniform distribution of high-density nitrogen, metal active sites and synergistic effect. Copyright © 2015 Elsevier Inc. All rights reserved.

Nitrogen source effects on the denitrifying anaerobic methane oxidation culture and anaerobic ammonium oxidation bacteria enrichment process.

Science.gov (United States)

Fu, Liang; Ding, Jing; Lu, Yong-Ze; Ding, Zhao-Wei; Zeng, Raymond J

2017-05-01

The co-culture system of denitrifying anaerobic methane oxidation (DAMO) and anaerobic ammonium oxidation (Anammox) has a potential application in wastewater treatment plant. This study explored the effects of permutation and combination of nitrate, nitrite, and ammonium on the culture enrichment from freshwater sediments. The co-existence of NO 3 - , NO 2 - , and NH 4 + shortened the enrichment time from 75 to 30 days and achieved a total nitrogen removal rate of 106.5 mg/L/day on day 132. Even though ammonium addition led to Anammox bacteria increase and a higher nitrogen removal rate, DAMO bacteria still dominated in different reactors with the highest proportion of 64.7% and the maximum abundance was 3.07 ± 0.25 × 10 8 copies/L (increased by five orders of magnitude) in the nitrite reactor. DAMO bacteria showed greater diversity in the nitrate reactor, and one was similar to M. oxyfera; DAMO bacteria in the nitrite reactor were relatively unified and similar to M. sinica. Interestingly, no DAMO archaea were found in the nitrate reactor. This study will improve the understanding of the impact of nitrogen source on DAMO and Anammox co-culture enrichment.

40 CFR 60.33b - Emission guidelines for municipal waste combustor metals, acid gases, organics, and nitrogen oxides.

Science.gov (United States)

2010-07-01

... combustor metals, acid gases, organics, and nitrogen oxides. 60.33b Section 60.33b Protection of Environment... Constructed on or Before September 20, 1994 § 60.33b Emission guidelines for municipal waste combustor metals, acid gases, organics, and nitrogen oxides. (a) The emission limits for municipal waste combustor metals...

Simultaneous removal of nitrogen oxide/nitrogen dioxide/sulfur dioxide from gas streams by combined plasma scrubbing technology.

Science.gov (United States)

Chang, Moo Been; Lee, How Ming; Wu, Feeling; Lai, Chi Ren

2004-08-01

Oxides of nitrogen (NOx) [nitrogen oxide (NO) + nitrogen dioxide (NO2)] and sulfur dioxide (SO2) are removed individually in traditional air pollution control technologies. This study proposes a combined plasma scrubbing (CPS) system for simultaneous removal of SO2 and NOx. CPS consists of a dielectric barrier discharge (DBD) and wet scrubbing in series. DBD is used to generate nonthermal plasmas for converting NO to NO2. The water-soluble NO2 then can be removed by wet scrubbing accompanied with SO2 removal. In this work, CPS was tested with simulated exhausts in the laboratory and with diesel-generator exhausts in the field. Experimental results indicate that DBD is very efficient in converting NO to NO2. More than 90% removal of NO, NOx, and SO2 can be simultaneously achieved with CPS. Both sodium sulfide (Na2S) and sodium sulfite (Na2SO3) scrubbing solutions are good for NO2 and SO2 absorption. Energy efficiencies for NOx and SO2 removal are 17 and 18 g/kWh, respectively. The technical feasibility of CPS for simultaneous removal of NO, NO2, and SO2 from gas streams is successfully demonstrated in this study. However, production of carbon monoxide as a side-product (approximately 100 ppm) is found and should be considered.

Environmental consequences from emission of nitrogen oxides and ammonia

International Nuclear Information System (INIS)

Iverfeldt, Aa.; Pleijel, H.; Klemedtsson, L.; Loevblad, G.; Omstedt, G.

1995-02-01

The aim of this study have been to compare environmental problems pertaining to nitrogen containing pollutants from power generation from biomass fuels. Local effects of NO x and NH 3 in air are normally small. Emission of NO x add plant toxic ozone, which is not the case at emission of NH 3 and N 2 O. The problem is slightly greater when siting in southern Sweden. The total emission of ammonium and nitrates are of major importance for acidification and nitrogen saturation. The largest contribution to the greenhouse effect comes from direct emission of nitrous oxide. The emission of N 2 O does not influence the siting aspects of the power plant, because of the global implications of this substance. 21 refs, 9 figs, 14 tabs

Influence of Process Parameters on Nitrogen Oxide Formation in

DEFF Research Database (Denmark)

Lans, Robert Pieter Van Der; Glarborg, Peter; Dam-Johansen, Kim

1997-01-01

This paper describes the influence of burner operating conditions, burner geometry and fuel parameters on the formation of nitrogen oxide during combustion of pulverized coal. Main attention has been paid to combustion test facilities with self-sustaining flames, while extensions have been made...... to full scale boilers and furnace modeling. Since coal combustion and flame aerodynamics have been reviewed earlier, these phenomena are only treated briefly....

Development of a mechanistically based computer simulation of nitrogen oxide absorption in packed towers

International Nuclear Information System (INIS)

Counce, R.M.

1981-01-01

A computer simulation for nitrogen oxide (NO/sub x/) scrubbing in packed towers was developed for use in process design and process control. This simulation implements a mechanistically based mathematical model, which was formulated from (1) an exhaustive literature review; (2) previous NO/sub x/ scrubbing experience with sieve-plate towers; and (3) comparisons of sequential sets of experiments. Nitrogen oxide scrubbing is characterized by simultaneous absorption and desorption phenomena: the model development is based on experiments designed to feature these two phenomena. The model was then successfully tested in experiments designed to put it in jeopardy

Studies on nitrogen oxides (NO{sub x} and N{sub 2}O) in pressurized fluidized bed combustion

Energy Technology Data Exchange (ETDEWEB)

Lu Yong

1998-09-01

This thesis describes the experimental studies of nitrogen oxide (NO, NO{sub 2}, N{sub 2}O) emissions in pressurized fluidized bed combustion (PFBC). In the first part of the thesis the background and the objectives of this study are introduced. The second part summarizes the fundamental knowledge about the formation and destruction of nitrogen oxides in coal combustion, particularly in the conditions of PFBC. The instrumentation of test facilities, measurement and data analysis is described in the third part. Then the most important experimental results follow in the next parts. The forth part describes the results from a PFBC test rig and an empirical modelling for predicting the emissions of NO{sub x} and N{sub 2}O. Finally, the fundamental work on coal combustion and fuel nitrogen conversion in a PFBC batch reactor is presented. These studies clearly confirm the potential of PFBC technology in the control nitrogen of oxide emissions. The research in the test rig was concentrated on determining the effects of process parameters on the emissions of nitrogen oxides with different fuels. Another objective was to examine the reduction of nitrogen oxides with the control methods in PFBC conditions, including ammonia injection and air staging combustion for reducing NO, and high temperature operations for reducing N{sub 2}0. The results indicate that pressurized operation suppresses the conversion of fuel-N to nitrogen oxides and favors with employing the reduction methods for further nitrogen oxide reduction, for instance the temperature window of NO reduction with ammonia injection has been found to be widened to even lower temperature range. Maximum reductions of 80-85 % with ammonia injection and 75-80 % with air staging combustion were achieved in the conditions examined. Considerably low emissions of N{sub 2}O (<7 ppm) were obtained in the tests of N{sub 2}O control, and thermal decomposition proved to be the laming pathway of N{sub 2}O destruction in PFBC. In

Nitrogen metabolism and kinetics of ammonia-oxidizing archaea.

Science.gov (United States)

Martens-Habbena, Willm; Stahl, David A

2011-01-01

The discovery of ammonia-oxidizing mesophilic and thermophilic Group I archaea changed the century-old paradigm that aerobic ammonia oxidation is solely mediated by two small clades of Beta- and Gammaproteobacteria. Group I archaea are extremely diverse and ubiquitous in marine and terrestrial environments, accounting for 20-30% of the microbial plankton in the global oceans. Recent studies indicated that many of these organisms carry putative ammonia monooxygenase genes and are more abundant than ammonia-oxidizing bacteria in most natural environments suggesting a potentially significant role in the nitrogen cycle. The isolation of Nitrosopumilus maritimus strain SCM1 provided the first direct evidence that Group I archaea indeed gain energy from ammonia oxidation. To characterize the physiology of this archaeal nitrifier, we developed a respirometry setup particularly suited for activity measurements in dilute microbial cultures with extremely low oxygen uptake rates. Here, we describe the setup and review the kinetic experiments conducted with N. maritimus and other nitrifying microorganisms. These experiments demonstrated that N. maritimus is adapted to grow on ammonia concentrations found in oligotrophic open ocean environments, far below the survival threshold of ammonia-oxidizing bacteria. The described setup and experimental procedures should facilitate physiological studies on other nitrifying archaea and oligotrophic microorganisms in general. Copyright © 2011 Elsevier Inc. All rights reserved.

Wisconsin's forests, 2004

Science.gov (United States)

Charles H. (Hobie) Perry; Vern A. Everson; Ian K. Brown; Jane Cummings-Carlson; Sally E. Dahir; Edward A. Jepsen; Joe Kovach; Michael D. Labissoniere; Terry R. Mace; Eunice A. Padley; Richard B. Rideout; Brett J. Butler; Susan J. Crocker; Greg C. Liknes; Randall S. Morin; Mark D. Nelson; Barry T. (Ty) Wilson; Christopher W. Woodall

2008-01-01

The first full, annualized inventory of Wisconsin's forests was completed in 2004 after 6,478 forested plots were visited. There are more than 16.0 million acres of forest land in the Wisconsin, nearly half of the State's land area; 15.8 million acres meet the definition of timberland. The total area of both forest land and timberland continues an upward...

Liquid Phase Plasma Synthesis of Iron Oxide Nanoparticles on Nitrogen-Doped Activated Carbon Resulting in Nanocomposite for Supercapacitor Applications.

Science.gov (United States)

Lee, Heon; Lee, Won-June; Park, Young-Kwon; Ki, Seo Jin; Kim, Byung-Joo; Jung, Sang-Chul

2018-03-25

Iron oxide nanoparticles supported on nitrogen-doped activated carbon powder were synthesized using an innovative plasma-in-liquid method, called the liquid phase plasma (LPP) method. Nitrogen-doped carbon (NC) was prepared by a primary LPP reaction using an ammonium chloride reactant solution, and an iron oxide/NC composite (IONCC) was prepared by a secondary LPP reaction using an iron chloride reactant solution. The nitrogen component at 3.77 at. % formed uniformly over the activated carbon (AC) surface after a 1 h LPP reaction. Iron oxide nanoparticles, 40~100 nm in size, were impregnated homogeneously over the NC surface after the LPP reaction, and were identified as Fe₃O₄ by X-ray photoelectron spectroscopy and X-ray diffraction. NC and IONCCs exhibited pseudo-capacitive characteristics, and their specific capacitance and cycling stability were superior to those of bare AC. The nitrogen content on the NC surface increased the compatibility and charge transfer rate, and the composites containing iron oxide exhibited a lower equivalent series resistance.

Oxidation Properties of Nitrogen-Doped Silicon Films Deposited from Si2H6 and NH3

Science.gov (United States)

Scheid, Emmanuel; Boyer, Pierre; Samitier, Josep; Hassani, Ahmed

1994-03-01

Si2H6/NH3 gas mixture was employed to obtain, by low-pressure chemical vapor deposition (LPCVD) at low temperature, nitrogen-doped silicon (NIDOS) films with various N/Si ratios. Thermal oxide was grown in dry oxygen at 900°C and 1100°C on NIDOS films. The result indicates that the nitrogen content of NIDOS films, assessed by X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR), greatly influences their oxidation rate.

New method of reducing emission of nitrogen oxides at coal-dust burning thermal power plants in Japan

Energy Technology Data Exchange (ETDEWEB)

Kotler, V.R.

1987-05-01

New method of suppressing nitrogen oxide formation in the combustion process makes use of SGR- or PM-burners in the combustion chamber, augmented with auxiliary burners positioned higher in the chamber for secondary fuel with insufficient air and nozzles above the latter for tertiary air. A description of laboratory experiments on the reduction of nitrogen oxides using the above burner configuration as well as a description of the reaction process taking place during combustion are presented. Results of industrial testing of the three-stage combustion of high-nitrogen Australian black coal in a cylindrical combustion chamber developed by Hitachi-Zosen are presented.

40 CFR 86.318-79 - Oxides of nitrogen analyzer specifications.

Science.gov (United States)

2010-07-01

... be at least 90 percent. (4) The quench interference must be less than 3.0 percent as measured in § 86.327. (b) Option. The oxides of nitrogen may be measured with an NDIR analyzer system that meets the following specifications: (1) The system shall include an NO2 to NO converter, a water trap, and an NDIR...

Oxidized Nitrogen Balance over 15 Months at Rural and Urban New York State Locations

Science.gov (United States)

Schwab, J. J.; Ninneman, M.; Marto, J.; Edgerton, E. S.; Blanchard, C. L.; Shaw, S. L.

2017-12-01

Continuous measurements of oxidized nitrogen species (NO, NO2, and HNO3), families of species (NOy, alkyl nitrates [or ANs], and peroxyacetyl nitrates [or PANs]), and particle nitrate (pNO3) were carried out for a fifteen-month period from August 2016 through October 2017 at two locations in New York State. The two sites were a rural research station at Pinnacle State Park in Addison, NY and an urban research station at Queens College in New York City. Four different chemiluminescence analyzers with various converters and denuders were employed to make these measurements. Instrumentation used for the study will be described, as well as some of the challenges created by combining data from these independent analyzers to address the oxidized nitrogen budget at the two sites. The Pinnacle State Park site often experiences quite clean air with low ppb levels of total NOy and a greater fraction of oxidized nitrogen products (NOz species). This contrasts with the urban Queens College location, which experiences stronger NOx sources. Seasonal differences in the NOx/NOy and NOz/NOy ratios, and the makeup of the NOz species, are also significant and will be explored in the presentation.

Band gap engineering of indium zinc oxide by nitrogen incorporation

Energy Technology Data Exchange (ETDEWEB)

Ortega, J.J., E-mail: jjosila@hotmail.com [Unidad Académica de Física, Universidad Autónoma de Zacatecas, Calzada Solidaridad esq. Paseo la Bufa, Fracc. Progreso, C.P. 98060 Zacatecas (Mexico); Doctorado Institucional de Ingeniería y Ciencia de Materiales, Universidad Autónoma de San Luis Potosí, Av. Salvador Nava, Zona Universitaria, C.P. 78270 San Luis Potosí (Mexico); Aguilar-Frutis, M.A.; Alarcón, G. [Centro de Investigación en Ciencia Aplicada y Tecnología Avanzada del Instituto Politécnico Nacional, Unidad Legaría, Calz. Legaría No. 694, Col. Irrigación, C.P. 11500 México D.F. (Mexico); Falcony, C. [Departamento de Física, Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional campus Zacatenco, Av. Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, C.P. 07360 México D.F. (Mexico); and others

2014-09-15

Highlights: • IZON thin films were deposited by RF reactive sputtering at room temperature. • The effects of nitrogen on physical properties of IZO were analyzed. • Optical properties of IZON were studied by SE and UV–vis spectroscopy. • Adachi and classical parameters were quantitative and qualitatively congruent. • Nitrogen induces a gradual narrowing band gap from 3.5 to 2.5 eV on IZON films. - Abstract: The effects of nitrogen incorporation in indium zinc oxide films, as grown by RF reactive magnetron sputtering, on the structural, electrical and optical properties were studied. It was determined that the variation of the N{sub 2}/Ar ratio, in the reactive gas flux, was directly proportional to the nitrogen percentage measured in the sample, and the incorporated nitrogen, which substituted oxygen in the films induces changes in the band gap of the films. This phenomenon was observed by measurement of absorption and transmission spectroscopy in conjunction with spectral ellipsometry. To fit the ellipsometry spectra, the classical and Adachi dispersion models were used. The obtained optical parameters presented notable changes related to the increment of the nitrogen in the film. The band gap narrowed from 3.5 to 2.5 eV as the N{sub 2}/Ar ratio was increased. The lowest resistivity obtained for these films was 3.8 × 10{sup −4} Ω cm with a carrier concentration of 5.1 × 10{sup 20} cm{sup −3}.

Band gap engineering of indium zinc oxide by nitrogen incorporation

International Nuclear Information System (INIS)

Ortega, J.J.; Aguilar-Frutis, M.A.; Alarcón, G.; Falcony, C.

2014-01-01

Highlights: • IZON thin films were deposited by RF reactive sputtering at room temperature. • The effects of nitrogen on physical properties of IZO were analyzed. • Optical properties of IZON were studied by SE and UV–vis spectroscopy. • Adachi and classical parameters were quantitative and qualitatively congruent. • Nitrogen induces a gradual narrowing band gap from 3.5 to 2.5 eV on IZON films. - Abstract: The effects of nitrogen incorporation in indium zinc oxide films, as grown by RF reactive magnetron sputtering, on the structural, electrical and optical properties were studied. It was determined that the variation of the N 2 /Ar ratio, in the reactive gas flux, was directly proportional to the nitrogen percentage measured in the sample, and the incorporated nitrogen, which substituted oxygen in the films induces changes in the band gap of the films. This phenomenon was observed by measurement of absorption and transmission spectroscopy in conjunction with spectral ellipsometry. To fit the ellipsometry spectra, the classical and Adachi dispersion models were used. The obtained optical parameters presented notable changes related to the increment of the nitrogen in the film. The band gap narrowed from 3.5 to 2.5 eV as the N 2 /Ar ratio was increased. The lowest resistivity obtained for these films was 3.8 × 10 −4 Ω cm with a carrier concentration of 5.1 × 10 20 cm −3

Catalyst for reduction of nitrogen oxides

Science.gov (United States)

Ott, Kevin C.

2010-04-06

A Selective Catalytic Reduction (SCR) catalyst was prepared by slurry coating ZSM-5 zeolite onto a cordierite monolith, then subliming an iron salt onto the zeolite, calcining the monolith, and then dipping the monolith either into an aqueous solution of manganese nitrate and cerium nitrate and then calcining, or by similar treatment with separate solutions of manganese nitrate and cerium nitrate. The supported catalyst containing iron, manganese, and cerium showed 80 percent conversion at 113 degrees Celsius of a feed gas containing nitrogen oxides having 4 parts NO to one part NO.sub.2, about one equivalent ammonia, and excess oxygen; conversion improved to 94 percent at 147 degrees Celsius. N.sub.2O was not detected (detection limit: 0.6 percent N.sub.2O).

Catalytic decomposition of nitrogen dioxide over various metal oxides

Energy Technology Data Exchange (ETDEWEB)

Shimokawabe, M; Ohi, A; Takezawa, N [Dept. of Chemical Process Engineering, Hokkaido Univ., Sapporo (Japan)

1992-06-30

The catalytic decomposition of nitrogen oxide (NO2) was investigated over 18 metal oxides (Al2O3, SiO2, ZrO2, SnO2, TiO2, V2O5, Cr2O3, MnO2, Fe2O3, Co3O4, NiO, CuO, ZnO, MgO, CaO, La2O3, CeO2, and Nd2O3). The relationship between the specific rates of metal oxides (Me{sub x}O{sub y}) (Me{sub x}O{sub y-1} + 1/2O{sub 2} {yields} Me{sub x}O{sub y}) shows a V-shaped curve with a minimum at -{Delta}H around 700 kJ/mol. This suggests that the mechanism dealt with in this article switches at -{Delta}H = 700 kJ/mol. 1 fig., 1 tab., 20 refs.

Nitrogen-doped reduced graphene oxide electrodes for electrochemical supercapacitors.

Science.gov (United States)

Nolan, Hugo; Mendoza-Sanchez, Beatriz; Ashok Kumar, Nanjundan; McEvoy, Niall; O'Brien, Sean; Nicolosi, Valeria; Duesberg, Georg S

2014-02-14

Herein we use Nitrogen-doped reduced Graphene Oxide (N-rGO) as the active material in supercapacitor electrodes. Building on a previous work detailing the synthesis of this material, electrodes were fabricated via spray-deposition of aqueous dispersions and the electrochemical charge storage mechanism was investigated. Results indicate that the functionalised graphene displays improved performance compared to non-functionalised graphene. The simplicity of fabrication suggests ease of up-scaling of such electrodes for commercial applications.

Mixing zones studies of the waste water discharge from the Consolidated Paper Company into the Wisconsin River at Wisconsin Rapids, Wisconsin

Science.gov (United States)

Hoopes, J. A.; Wu, D. S.; Ganatra, R.

1973-01-01

Effluent concentration distributions from the waste water discharge of the Kraft Division Mill, Consolidated Paper Company, into the Wisconsin River at Wisconsin Rapids, Wisconsin, is investigated. Effluent concentrations were determined from measurements of the temperature distribution, using temperature as a tracer. Measurements of the velocity distribution in the vicinity of the outfall were also made. Due to limitations in the extent of the field observations, the analysis and comparison of the measurements is limited to the region within about 300 feet from the outfall. Effects of outfall submergence, of buoyancy and momentum of the effluent and of the pattern and magnitude of river currents on these characteristics are considered.

Behaviour of electroinsulating polyethylene and polyvinil-chloride-based materials in the contact with nitrogen oxides

International Nuclear Information System (INIS)

Korolev, V.M.; Koroleva, G.N.; Il'yukhina, Ya.A.

1987-01-01

The compatibility of electric cable sheaths on polyethylene and polyvinylchloride base with nitrogen tetroxide has been studied. It is shown, that the cables with polyethylene sheaths are compatible with N 2 O 4 and can be used in the conditions of the contact with it within 5 hours. Polyvinylchloride is incompatible with nitrogen oxide and polyvinylchloride based cables can be used only with oxides concentraton don't exceeding 0,5 g/l. Under the effect of high concentrations before dismounting or conducting works after accidents, these cables need special treatment for eliminating impact sensitivity acquired in the conditions of contamination

Prediction of traffic-related nitrogen oxides concentrations using Structural Time-Series models

Science.gov (United States)

Lawson, Anneka Ruth; Ghosh, Bidisha; Broderick, Brian

2011-09-01

Ambient air quality monitoring, modeling and compliance to the standards set by European Union (EU) directives and World Health Organization (WHO) guidelines are required to ensure the protection of human and environmental health. Congested urban areas are most susceptible to traffic-related air pollution which is the most problematic source of air pollution in Ireland. Long-term continuous real-time monitoring of ambient air quality at such urban centers is essential but often not realistic due to financial and operational constraints. Hence, the development of a resource-conservative ambient air quality monitoring technique is essential to ensure compliance with the threshold values set by the standards. As an intelligent and advanced statistical methodology, a Structural Time Series (STS) based approach has been introduced in this paper to develop a parsimonious and computationally simple air quality model. In STS methodology, the different components of a time-series dataset such as the trend, seasonal, cyclical and calendar variations can be modeled separately. To test the effectiveness of the proposed modeling strategy, average hourly concentrations of nitrogen dioxide and nitrogen oxides from a congested urban arterial in Dublin city center were modeled using STS methodology. The prediction error estimates from the developed air quality model indicate that the STS model can be a useful tool in predicting nitrogen dioxide and nitrogen oxides concentrations in urban areas and will be particularly useful in situations where the information on external variables such as meteorology or traffic volume is not available.

A Generalizable Top-Down Nanostructuring Method of Bulk Oxides: Sequential Oxygen-Nitrogen Exchange Reaction.

Science.gov (United States)

Lee, Lanlee; Kang, Byungwuk; Han, Suyoung; Kim, Hee-Eun; Lee, Moo Dong; Bang, Jin Ho

2018-05-27

A thermal reaction route that induces grain fracture instead of grain growth is devised and developed as a top-down approach to prepare nanostructured oxides from bulk solids. This novel synthesis approach, referred to as the sequential oxygen-nitrogen exchange (SONE) reaction, exploits the reversible anion exchange between oxygen and nitrogen in oxides that is driven by a simple two-step thermal treatment in ammonia and air. Internal stress developed by significant structural rearrangement via the formation of (oxy)nitride and the creation of oxygen vacancies and their subsequent combination into nanopores transforms bulk solid oxides into nanostructured oxides. The SONE reaction can be applicable to most transition metal oxides, and when utilized in a lithium-ion battery, the produced nanostructured materials are superior to their bulk counterparts and even comparable to those produced by conventional bottom-up approaches. Given its simplicity and scalability, this synthesis method could open a new avenue to the development of high-performance nanostructured electrode materials that can meet the industrial demand of cost-effectiveness for mass production. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Well-dispersed NiO nanoparticles supported on nitrogen-doped carbon nanotube for methanol electrocatalytic oxidation in alkaline media

Energy Technology Data Exchange (ETDEWEB)

Wang, Pengcheng; Zhou, Yingke, E-mail: zhouyk888@hotmail.com; Hu, Min; Chen, Jian

2017-01-15

Highlights: • Nitrogen-doped carbon nanotube supporting ultrafine NiO nanoparticles with high dispersity are facile synthesized. • The nitrogen doping, calcination temperature and NiO loading present great effects on the catalyst morphology, structure and electrochemical performance. • NiO-NCNT-3x-400 demonstrates remarkable catalytic activity and stability for the methanol electrolytic oxidation reaction. - Abstract: Nitrogen-doped carbon nanotube supporting NiO nanoparticles were synthesized by a chemical precipitation process coupled with subsequent calcination. The morphology and structure of the composites were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), and the electrochemical performance was evaluated using cyclic voltammetry and chronoamperometric technique. The effects of nitrogen doping, calcination temperature and content of NiO nanoparticles on the electrocatalytic activity toward methanol oxidation were systematically studied. The results show that the uniformly dispersed ultrafine NiO nanoparticles supported on nitrogen-doped carbon nanotube are obtained after calcination at 400 °C. The optimized composite catalysts present high electrocatalytic activity, fast charge-transfer process, excellent accessibility and stability for methanol oxidation reaction, which are promising for application in the alkaline direct methanol fuel cells.

Synthesis of Nitrogen-Doped Mesoporous Carbon for the Catalytic Oxidation of Ethylbenzene

Science.gov (United States)

Wang, Ruicong; Yu, Yifeng; Zhang, Yue; Lv, Haijun; Chen, Aibing

2017-06-01

Nitrogen-doped ordered mesoporous carbon (NOMC) was fabricated via a simple hard-template method by functionalized ionic liquids as carbon and nitrogen source, SBA-15 as a hard-template. The obtained NOMC materials have a high nitrogen content of 5.55 %, a high surface area of 446.2 m2 g-1, and an excellent performance in catalysing oxidation of ethylbenzene. The conversion rate of ethylbenzene can be up to 84.5% and the yield of acetophenone can be up to 69.9%, the results indicated that the NOMC materials have a faster catalytic rate and a higher production of acetophenone than catalyst-free and CMK-3, due to their uniform pore size, high surface area and rich active sites in the carbon pore walls.

Emissions of nitrogen oxides and particulates of diesel vehicles

OpenAIRE

Kadijk, G.; Ligterink, N.E.; Mensch, P. van; Spreen, J.S.; Vermeulen, R.J.; Vonk, W.A.

2015-01-01

In real-world conditions, modern Euro VI heavy-duty vehicles produce an average of ten times less nitrogen oxide (NOx)emissions than previous generations of Euro IV and Euro V heavy-duty vehicles. However, Euro 6 passenger cars and light commercial vehicles present an entirely different picture since, despite a continual tightening of European emissions limits, the real-world NOx emissions of new diesel passenger cars and light commercial vehicles have remained virtually unchanged over the la...

Experimental identification of nitrogen-vacancy complexes in nitrogen implanted silicon

Science.gov (United States)

Adam, Lahir Shaik; Law, Mark E.; Szpala, Stanislaw; Simpson, P. J.; Lawther, Derek; Dokumaci, Omer; Hegde, Suri

2001-07-01

Nitrogen implantation is commonly used in multigate oxide thickness processing for mixed signal complementary metal-oxide-semiconductor and System on a Chip technologies. Current experiments and diffusion models indicate that upon annealing, implanted nitrogen diffuses towards the surface. The mechanism proposed for nitrogen diffusion is the formation of nitrogen-vacancy complexes in silicon, as indicated by ab initio studies by J. S. Nelson, P. A. Schultz, and A. F. Wright [Appl. Phys. Lett. 73, 247 (1998)]. However, to date, there does not exist any experimental evidence of nitrogen-vacancy formation in silicon. This letter provides experimental evidence through positron annihilation spectroscopy that nitrogen-vacancy complexes indeed form in nitrogen implanted silicon, and compares the experimental results to the ab initio studies, providing qualitative support for the same.

Production of nitrogen oxides in air pulse-periodic discharge with apokamp

Science.gov (United States)

Panarin, Victor A.; Skakun, Victor S.; Sosnin, Eduard A.; Tarasenko, Victor F.

2018-05-01

The decomposition products of pulse-periodic discharge atmospheric pressure plasma in apokamp, diffuse and corona modes were determined by optical and chemical methods. It is shown that apokamp discharge formation starts at a critical value of dissipation power in a discharge channel. Simultaneously, due to the thermochemical reactions, plasma starts to efficiently produce nitrogen oxides.

Observations of the diurnal and seasonal trends in nitrogen oxides in the western Sierra Nevada

Directory of Open Access Journals (Sweden)

J. G. Murphy

2006-01-01

Full Text Available Observations of speciated nitrogen oxides, namely NO2, total peroxy nitrates (ΣPNs, total alkyl nitrates (ΣANs, and HNO3 by thermal dissociation laser induced fluorescence (TD-LIF, and supporting chemical and meteorological measurements at Big Hill (1860 m, a high elevation site in California's Sierra Nevada Mountains, are described. From May through October, terrain-driven winds in the region routinely bring air from Sacramento, 100 km southwest of the site, upslope over oak and pine forests to Big Hill during the day, while at night, the site often samples clean, dry air characteristic of the free troposphere. Winter differs mainly in that the meteorology does not favour the buildup of Sacramento's pollution over the Sierra Nevada range, and the urban-influenced air that is seen has been less affected by biogenic VOC emissions, resulting in longer lifetime for NO2 and a predominance of the inorganic forms of nitrogen oxides. Summertime observations at Big Hill can be compared with those from Granite Bay, a Sacramento suburb, and from the University of California's Blodgett Forest Research Station to examine the evolution of nitrogen oxides and ozone within the urban plume. Nitrogen oxide radicals (NO and NO2, which dominate total nitrogen oxides (NOy at Granite Bay, are rapidly converted into HNO3, ΣPNs, and ΣANs, such that these compounds contribute 29, 30, and 21% respectively to the NOy budget in the plume at Big Hill. Nevertheless, the decreasing concentrations of NO2 as the plume is advected to Big Hill lead to decreases in the production rate of HNO3 and ozone. The data also demonstrate the role that temperature plays in sequestering NO2 into peroxy nitrates, effectively decreasing the rate of ozone production. The important contribution of ΣANs to NOy in the region suggests that they should be considered with regards to export of NOy from the boundary layer. Nocturnal observations of airmasses characteristic of the

Forests of Wisconsin, 2013

Science.gov (United States)

Charles H. Perry

2014-01-01

This resource update provides an overview of forest resources in Wisconsin based on an inventory conducted by the U.S. Forest Service, Forest Inventory and Analysis (FIA) program at the Northern Research Station in cooperation with the Wisconsin Department of Natural Resources. Data estimates are based on field data collected using the FIA annualized sample design and...

Yellowing of coated papers under the action of heat, daylight radiation, and nitrogen oxide gas

International Nuclear Information System (INIS)

Mailly, V.; Le Nest, J.F.; Tosio, J.M.S.; Silvy, J.

1997-01-01

In the area of coated papers, a high degree of whiteness is often required to carry a quality image. Coated papers however are sensitive to the environment where they are stored and have tendency to yellow. The aim of this work was to study the influence of(i) daylight radiation and (ii) nitrogen oxide gas (NO2 ) on the yellowing of coated papers. In a previous study (l), we had established the presence of NO2 in the environment of some coating machines because of the transformation of ammonium hydroxide (NH4 OH, a component of some coating colors) into nitrogen oxide through the burners of hot air supplier-systems

Influence of nitrogen oxides NO and NO2 on singlet delta oxygen production in pulsed discharge

International Nuclear Information System (INIS)

Ionin, A A; Klimachev, Yu M; Kozlov, A Yu; Kotkov, A A; Rulev, O A; Seleznev, L V; Sinitsyn, D V; Vagin, N P; Yuryshev, N N; Kochetov, I V; Napartovich, A P

2009-01-01

The influence of nitrogen oxides NO and NO 2 on the specific input energy (SIE) and the time behaviour of singlet delta oxygen (SDO) luminescence excited by a pulsed e-beam sustained discharge in oxygen were experimentally and theoretically studied. NO and NO 2 addition into oxygen results in a small increase and decrease in the SIE, respectively, the latter being connected with a large energy of electron affinity to NO 2 . The addition of 0.1-0.3% nitrogen oxides was experimentally and theoretically demonstrated to result in a notable enhancement of the SDO lifetime, which is related to a decrease in the atomic oxygen concentration in afterglow. It was experimentally demonstrated that to get a high SDO concentration at the gas pressure 30-60 Torr for a time interval of less than ∼0.5 s one needs to add not less than 0.2% nitrogen oxides into oxygen. The temperature dependence of the relaxation constant for SDO quenching by unexcited oxygen was estimated by using experimental data on the time behaviour of SDO luminescence.

Mechanisms of formation and destruction of nitrogen oxides during polyamide incineration in a fluidized bed

Energy Technology Data Exchange (ETDEWEB)

Hahnel, F; Gadiou, R; Prado, G [Univ. de Haute Alsace, Mulhouse (France). Lab. de Gestion des Risques et Environnement

1998-09-01

In order to study the incineration of nitrogen-containing polymers, a fludized bed has been built. This paper reports the results for polyamide 6-6 incineration. The main nitrogen containing species have been identified, and the axial profiles of concentration of nitrogen oxides, HCN and NH3 have been measured. The main steps of decomposition of the polyamide were identified. We present an experimental investigation of the influence of operating parameters (temperature, excess air) on the formation and reduction of polymer combustion products. The yields of conversion of nitrogen to the different N-species have been calculated as a function of excess air in the fluidized bed. (orig.)

Nitrogen oxide emissions from a kraft recovery furnace

International Nuclear Information System (INIS)

Prouty, A.L.; Stuart, R.C.; Caron, A.L.

1993-01-01

Nitrogen Oxide (NOx) emissions from a rebuilt kraft recovery furnace slightly exceeded the specified limit of 1.1 lb/ton (0.55 kg/metric ton) of black-liquor solids. Mill trials were undertaken to determine whether NOx emissions could be minimized by modifying furnace operation. NOx emissions increased when secondary air was shifted to tertiary ports. NOx emissions fell when the amounts of primary and total air were decreased, but this increased emissions of other pollutants. After demonstrating that best operation of the furnace could not meet the permit with an emissions limit that matched the furnace's performance at best operation

Metatranscriptomic and metagenomic description of the bacterial nitrogen metabolism in waste water wet oxidation effluents

Directory of Open Access Journals (Sweden)

Julien Crovadore

2017-10-01

Full Text Available Anaerobic digestion is a common method for reducing the amount of sludge solids in used waters and enabling biogas production. The wet oxidation process (WOX improves anaerobic digestion by converting carbon into methane through oxidation of organic compounds. WOX produces effluents rich in ammonia, which must be removed to maintain the activity of methanogens. Ammonia removal from WOX could be biologically operated by aerobic granules. To this end, granulation experiments were conducted in 2 bioreactors containing an activated sludge (AS. For the first time, the dynamics of the microbial community structure and the expression levels of 7 enzymes of the nitrogen metabolism in such active microbial communities were followed in regard to time by metagenomics and metatranscriptomics. It was shown that bacterial communities adapt to the wet oxidation effluent by increasing the expression level of the nitrogen metabolism, suggesting that these biological activities could be a less costly alternative for the elimination of ammonia, resulting in a reduction of the use of chemicals and energy consumption in sewage plants. This study reached a strong sequencing depth (from 4.4 to 7.6 Gb and enlightened a yet unknown diversity of the microorganisms involved in the nitrogen pathway. Moreover, this approach revealed the abundance and expression levels of specialised enzymes involved in nitrification, denitrification, ammonification, dissimilatory nitrate reduction to ammonium (DNRA and nitrogen fixation processes in AS. Keywords: Applied sciences, Biological sciences, Environmental science, Genetics, Microbiology

The global lightning-induced nitrogen oxides source

Directory of Open Access Journals (Sweden)

U. Schumann

2007-07-01

Full Text Available The knowledge of the lightning-induced nitrogen oxides (LNO_x source is important for understanding and predicting the nitrogen oxides and ozone distributions in the troposphere and their trends, the oxidising capacity of the atmosphere, and the lifetime of trace gases destroyed by reactions with OH. This knowledge is further required for the assessment of other important NO_x sources, in particular from aviation emissions, the stratosphere, and from surface sources, and for understanding the possible feedback between climate changes and lightning. This paper reviews more than 3 decades of research. The review includes laboratory studies as well as surface, airborne and satellite-based observations of lightning and of NO_x and related species in the atmosphere. Relevant data available from measurements in regions with strong LNO_x influence are identified, including recent observations at midlatitudes and over tropical continents where most lightning occurs. Various methods to model LNO_x at cloud scales or globally are described. Previous estimates are re-evaluated using the global annual mean flash frequency of 44±5 s⁻¹ reported from OTD satellite data. From the review, mainly of airborne measurements near thunderstorms and cloud-resolving models, we conclude that a "typical" thunderstorm flash produces 15 (2–40×10²⁵ NO molecules per flash, equivalent to 250 mol NO_x or 3.5 kg of N mass per flash with uncertainty factor from 0.13 to 2.7. Mainly as a result of global model studies for various LNO_x parameterisations tested with related observations, the best estimate of the annual global LNO_x nitrogen mass source and its uncertainty range is (5±3 Tg a⁻¹ in this study. In spite of a smaller global flash rate, the best estimate is essentially the same as in some earlier reviews, implying larger flash-specific NO

Corn nitrogen management influences nitrous oxide emissions in drained and undrained soils

Science.gov (United States)

Tile-drainage and nitrogen (N) fertilization are important for corn (Zea mays L.) production. To date, no studies have evaluated nitrous oxide (N2O) emissions of single vs. split-N fertilizer application under different soil drainage conditions. The objective of this study was to quantify season-lon...

40 CFR 50.11 - National primary and secondary ambient air quality standards for oxides of nitrogen (with...

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 2 2010-07-01 2010-07-01 false National primary and secondary ambient air quality standards for oxides of nitrogen (with nitrogen dioxide as the indicator). 50.11 Section 50.11 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS NATIONAL...

Development of Green Pavement for Reducing Oxides of Nitrogen (NOx in the Ambient Air

Directory of Open Access Journals (Sweden)

Kania Dewi

2016-05-01

Full Text Available The transportation sector is the biggest contributor to air pollution in Indonesia, especially in metropolitan cities. Gases such as oxides of nitrogen (NOx are produced during the combustion of fossil fuels in the internal combustion of vehicle engines. Oxides of nitrogen such as nitric oxide (NO and nitrogen dioxide (NO2 are important air pollutants, because they cause significant harm to human health and play an important role in being precursors of other dangerous pollutants such as photochemical smog. One of the simple ways to reduce NOx concentrations is utilizing a catalytic process involving UV light and semiconductor particles such as TiO2. Illuminated TiO2 UV light is capable of producing an electron (e- and hole (h- pair, which initiates a chemical reaction that alters the NOx to become NO3- or NO2-. A field scale paving block reactor coated with TiO2 placed by the roadside was exposed to UV light using various exposure times. The results showed that the sample with a composition of 200 g/m2 TiO2 was capable of adsorbing NOx gas at an average rate of 0.0046 mg/m2/minute. Additional costs due to TiO2 coating for every square meter of paving are IDR 13,180.

Effect of operational cycle time length on nitrogen removal in an alternating oxidation ditch system.

Science.gov (United States)

Mantziaras, I D; Stamou, A; Katsiri, A

2011-06-01

This paper refers to nitrogen removal optimization of an alternating oxidation ditch system through the use of a mathematical model and pilot testing. The pilot system where measurements have been made has a total volume of 120 m(3) and consists of two ditches operating in four phases during one cycle and performs carbon oxidation, nitrification, denitrification and settling. The mathematical model consists of one-dimensional mass balance (convection-dispersion) equations based on the IAWPRC ASM 1 model. After the calibration and verification of the model, simulation system performance was made. Optimization is achieved by testing operational cycles and phases with different time lengths. The limits of EU directive 91/271 for nitrogen removal have been used for comparison. The findings show that operational cycles with smaller time lengths can achieve higher nitrogen removals and that an "equilibrium" between phase time percentages in the whole cycle, for a given inflow, must be achieved.

Potential roles of anaerobic ammonium and methane oxidation in the nitrogen cycle of wetland ecosystems.

Science.gov (United States)

Zhu, Guibing; Jetten, Mike S M; Kuschk, Peter; Ettwig, Katharina F; Yin, Chengqing

2010-04-01

Anaerobic ammonium oxidation (anammox) and anaerobic methane oxidation (ANME coupled to denitrification) with nitrite as electron acceptor are two of the most recent discoveries in the microbial nitrogen cycle. Currently the anammox process has been relatively well investigated in a number of natural and man-made ecosystems, while ANME coupled to denitrification has only been observed in a limited number of freshwater ecosystems. The ubiquitous presence of anammox bacteria in marine ecosystems has changed our knowledge of the global nitrogen cycle. Up to 50% of N(2) production in marine sediments and oxygen-depleted zones may be attributed to anammox bacteria. However, there are only few indications of anammox in natural and constructed freshwater wetlands. In this paper, the potential role of anammox and denitrifying methanotrophic bacteria in natural and artificial wetlands is discussed in relation to global warming. The focus of the review is to explore and analyze if suitable environmental conditions exist for anammox and denitrifying methanotrophic bacteria in nitrogen-rich freshwater wetlands.

Nitrogen loss from grassland on peat soils through nitrous oxide production.

NARCIS (Netherlands)

Koops, J.G.; Beusichem, van M.L.; Oenema, O.

1997-01-01

Nitrous oxide (N2O) in soils is produced through nitrification and denitrification. The N2O produced is considered as a nitrogen (N) loss because it will most likely escape from the soil to the atmosphere as N2O or N2. Aim of the study was to quantify N2O production in grassland on peat soils in

Effect of nitrogen addition on the structural, electrical, and optical properties of In-Sn-Zn oxide thin films

Energy Technology Data Exchange (ETDEWEB)

Jia, Junjun, E-mail: jia@chem.aoyama.ac.jp [Graduate School of Science and Engineering, Aoyama Gakuin University, 5-10-1 Fuchinobe, Chuo, Sagamihara, Kanagawa 252-5258 (Japan); Torigoshi, Yoshifumi; Suko, Ayaka; Nakamura, Shin-ichi [Graduate School of Science and Engineering, Aoyama Gakuin University, 5-10-1 Fuchinobe, Chuo, Sagamihara, Kanagawa 252-5258 (Japan); Kawashima, Emi; Utsuno, Futoshi [Advanced Technology Research Laboratories, Idemitsu Kosan Co., Ltd., Sodegaura, Chiba 299-0293 (Japan); Shigesato, Yuzo, E-mail: yuzo@chem.aoyama.ac.jp [Graduate School of Science and Engineering, Aoyama Gakuin University, 5-10-1 Fuchinobe, Chuo, Sagamihara, Kanagawa 252-5258 (Japan)

2017-02-28

Highlights: • Nitrogen addition induces the structure of ITZO film change from amorphous phase to a c-axis oriented InN polycrystalline phase. • Nitrogen addition suppressed the formation of oxygen-related vacancies in ITZO films. • A red-shift in the optical band edge for ITZO films was observed as the nitrogen flow ratio increased, which was due to the generation of InN crystallites. - Abstract: Indium-tin-zinc oxide (ITZO) films were deposited at various nitrogen flow ratios using magnetron sputtering. At a nitrogen flow ratio of 40%, the structure of ITZO film changed from amorphous, with a short-range-ordered In{sub 2}O{sub 3} phase, to a c-axis oriented InN polycrystalline phase, where InN starts to nucleate from an amorphous In{sub 2}O{sub 3} matrix. Whereas, nitrogen addition had no obvious effect on the structure of indium-gallium-zinc oxide (IGZO) films even at a nitrogen flow ratio of 100%. Nitrogen addition also suppressed the formation of oxygen-related vacancies in ITZO films when the nitrogen flow ratio was less than 20%, and higher nitrogen addition led to an increase in carrier density. Moreover, a red-shift in the optical band edge was observed as the nitrogen flow ratio increased, which could be attributed to the generation of InN crystallites. We anticipate that the present findings demonstrating nitrogen-addition induced structural changes can help to understand the environment-dependent instability in amorphous IGZO or ITZO based thin-film transistors (TFTs).

Loss of nitrogen (study with 15N) as gaseous oxides under submerged conditions of paddy

International Nuclear Information System (INIS)

Mandal, S.R.; Datta, N.P.

1987-01-01

The experiment in a specially designed, air-tight pot with rice and different water soluble grades of nitrophosphate, ammonium nitrate (plus super phosphate) tagged with six atom per cent excess 15 N clearly revealed that the loss of nitrogen as oxides during the growth period of rice under submerged condition was very small (1.48 to 2.57 mg/pot). The 15 N content in the lost oxides was also very small and a small traction of total nitrogen applied represented the loss in this channel (0.0062 to 0.0163 per cent). The loss was influenced by NH 4 :NO 3 ratio in the fertilizer and increased with the increasing quantity of nitrate present in the fertilizers. (author)

Problem of formation of nitrogen oxides during coal combustion in power plant steam generators

Energy Technology Data Exchange (ETDEWEB)

Kotler, V.R.; Kuvaev, Yu.V.

1992-07-01

Analyzes a study of physical and chemical processes of nitrogen oxide formation during coal combustion conducted at Stanford University (USA). Experimental installation, pulverized coal feeding as well as measuring techniques and equipment are described. Experiments were conducted with 55 micron particles of semibituminous coal. An equation for the percentage of coal carbon converted to gaseous products is given. Active formation of NO from nitrogen content in the fuel was observed when oxygen content was under 4%. Conversion of the fuel nitrogen to NO[sub x] in the 1,350-1,850 K temperature range did not depend on gas temperature but rather on oxygen content. 2 refs.

Zinc-oxide nanorod / copper-oxide thin-film heterojunction for a nitrogen-monoxide gas sensor

International Nuclear Information System (INIS)

Yoo, Hwansu; Kim, Hyojin; Kim, Dojin

2014-01-01

A novel p - n oxide heterojunction structure was fabricated by employing n-type zinc-oxide (ZnO) nanorods grown on an indium-tin-oxide-coated glass substrate by using the hydrothermal method and a p-type copper-oxide (CuO) thin film deposited onto the ZnO nanorod array by using the sputtering method. The crystallinities and microstructures of the heterojunction materials were examined by using X-ray diffraction and scanning electron microscopy. The observed current - voltage characteristics of the p - n oxide heterojunction showed a nonlinear diode-like rectifying behavior. The effects of an oxidizing or electron acceptor gas, such as nitrogen monoxide (NO), on the ZnO nanorod/CuO thin-film heterojunction were investigated to determine the potential applications of the fabricated material for use in gas sensors. The forward current of the p - n heterojunction was remarkably reduced when NO gas was introduced into dry air at temperatures from 100 to 250 .deg. C. The NO gas response of the oxide heterojunction reached a maximum value at an operating temperature of 180 .deg. C and linearly increased as the NO gas concentration was increased from 5 to 30 ppm. The sensitivity value was observed to be as high as 170% at 180 .deg. C when biased at 2 V in the presence of 20-ppm NO. The ZnO nanorod/CuO thin-film heterojunction also exhibited a stable and repeatable response to NO gas. The experimental results suggest that the ZnO nanorod/CuO thin-film heterojunction structure may be a novel candidate for gas sensors.

Zinc-oxide nanorod / copper-oxide thin-film heterojunction for a nitrogen-monoxide gas sensor

Energy Technology Data Exchange (ETDEWEB)

Yoo, Hwansu; Kim, Hyojin; Kim, Dojin [Chungnam National University, Daejeon (Korea, Republic of)

2014-11-15

A novel p - n oxide heterojunction structure was fabricated by employing n-type zinc-oxide (ZnO) nanorods grown on an indium-tin-oxide-coated glass substrate by using the hydrothermal method and a p-type copper-oxide (CuO) thin film deposited onto the ZnO nanorod array by using the sputtering method. The crystallinities and microstructures of the heterojunction materials were examined by using X-ray diffraction and scanning electron microscopy. The observed current - voltage characteristics of the p - n oxide heterojunction showed a nonlinear diode-like rectifying behavior. The effects of an oxidizing or electron acceptor gas, such as nitrogen monoxide (NO), on the ZnO nanorod/CuO thin-film heterojunction were investigated to determine the potential applications of the fabricated material for use in gas sensors. The forward current of the p - n heterojunction was remarkably reduced when NO gas was introduced into dry air at temperatures from 100 to 250 .deg. C. The NO gas response of the oxide heterojunction reached a maximum value at an operating temperature of 180 .deg. C and linearly increased as the NO gas concentration was increased from 5 to 30 ppm. The sensitivity value was observed to be as high as 170% at 180 .deg. C when biased at 2 V in the presence of 20-ppm NO. The ZnO nanorod/CuO thin-film heterojunction also exhibited a stable and repeatable response to NO gas. The experimental results suggest that the ZnO nanorod/CuO thin-film heterojunction structure may be a novel candidate for gas sensors.

Reactive nitrogen oxides and ozone above a taiga woodland

Science.gov (United States)

Bakwin, Peter S.; Jacob, Daniel J.; Wofsy, Steven C.; Munger, J. William; Daube, Bruce C.; Bradshaw, John D.; Sandholm, Scott T.; Talbot, Robert W.; Singh, Hanwant B.; Gregory, Gerald L.

1994-01-01

Measurements of reactive nitrogen oxides (NO(x) and NO(y)) and ozone (O3) were made in the planetary boundary layer (PBL) above a taiga woodland in northern Quebec, Canada, during June-August, 1990, as part of NASA Artic Boundary Layer Expedition (ABLE) 3B. Levels of nitrogen oxides and O3 were strongly modulated by the synoptic scale meteorology that brought air from various source regions to the site. Industrial pollution from the Great Lakes region of the U.S. and Canada appears to be a major source for periodic elevation of NO(x), and NO(y) and O3. We find that NO/NO2 ratios at this site at midday were approximately 50% those expected from a simple photochemical steady state between NO(x) and O3, in contrast to our earlier results from the ABLE 3A tundra site. The difference between the taiga and tundra sites is likely due to much larger emissions of biogenic hydrocarbons (particularly isoprene) from the taiga vegetation. Hydrocarbon photooxidation leads to relatively rapid production of peroxy radicals, which convert NO to NO2, at the taiga site. Ratios of NO(x) to NO(y) were typically 2-3 times higher in the PBL during ABLE 3B than during ABLE 3A. This is probably the result of high PAN levels and suppressed formation of HNO3 from NO2 due to high levels of biogenic hydrocarbons at the ABLE 3B site.

A Continuous Flow System for the Measurement of Ambient Nitrogen Oxides [NO + NO] Using Rhodamine B Hydrazide as a Chemosensor

Directory of Open Access Journals (Sweden)

Pandurangappa Malingappa

2014-01-01

Full Text Available A new chemosensor has been used to monitor atmospheric nitrogen oxides [NO + NO 2 ] at parts per billion (ppb level. It is based on the catalytic reaction of nitrogen oxides with rhodamine B hydrazide (RBH to produce a colored compound through the hydrolysis of the amide bond of the molecule. A simple colorimeter has been used to monitor atmospheric nitrogen dioxide at ppb level. The air samples were purged through a sampling cuvette containing RBH solution using peristaltic pump. The proposed method has been successfully applied to monitor the ambient nitrogen dioxide levels at traffic junction points within the city limits and the results obtained are compared with the standard Griess-Ilosvay method.

Insights into high-temperature nitrogen cycling from studies of the thermophilic ammonia-oxidizing archaeon Nitrosocaldus yellowstonii. (Invited)

Science.gov (United States)

de la Torre, J. R.

2010-12-01

Our understanding of the nitrogen cycle has advanced significantly in recent years with the discovery of new metabolic processes and the recognition that key processes such as aerobic ammonia oxidation are more broadly distributed among extant organisms and habitat ranges. Nitrification, the oxidation of ammonia to nitrite and nitrate, is a key component of the nitrogen cycle and, until recently, was thought to be mediated exclusively by the ammonia-oxidizing bacteria (AOB). The discovery that mesophilic marine archaea, some of the most abundant microorganisms on the planet, are capable of oxidizing ammonia to nitrite fundamentally changed our perception of the global nitrogen cycle. Ammonia-oxidizing archaea (AOA) are now thought to be significant drivers of nitrification in many marine and terrestrial environments. Most studies, however, have focused on the contribution of AOA to nitrogen cycling in mesophilic environments. Our recent discovery of a thermophilic AOA, Nitrosocaldus yellowstonii, has expanded the role and habitat range of AOA to include high temperature environments. Numerous studies have shown that AOA are widely distributed in geothermal habitats with a wide range of temperature and pH. The availability of multiple AOA genome sequences, combined with metagenomic studies from mesophilic and thermophilic environments gives us a better understanding of the physiology, ecology and evolution of these organisms. Recent studies have proposed that the AOA represent the most deeply branching lineage within the Archaea, the Thaumarchaeota. Furthermore, genomic comparisons between AOA and AOB reveal significant differences in the proposed pathways for ammonia oxidation. These genetic differences likely explain fundamental physiological differences such as the resistance of N. yellowstonii and other AOA to the classical nitrification inhibitors allylthiourea and acetylene. Physiological studies suggest that the marine AOA are adapted to oligotrophic

40 CFR Appendix B to Part 76 - Procedures and Methods for Estimating Costs of Nitrogen Oxides Controls Applied to Group 1, Boilers

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Procedures and Methods for Estimating Costs of Nitrogen Oxides Controls Applied to Group 1, Boilers B Appendix B to Part 76 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) ACID RAIN NITROGEN OXIDES...

The nitrogen cycle: Atmosphere interactions

Science.gov (United States)

Levine, J. S.

1984-01-01

Atmospheric interactions involving the nitrogen species are varied and complex. These interactions include photochemical reactions, initiated by the absorption of solar photons and chemical kinetic reactions, which involve both homogeneous (gas-to-gas reactions) and heterogeneous (gas-to-particle) reactions. Another important atmospheric interaction is the production of nitrogen oxides by atmospheric lightning. The nitrogen cycle strongly couples the biosphere and atmosphere. Many nitrogen species are produced by biogenic processes. Once in the atmosphere nitrogen oxides are photochemically and chemically transformed to nitrates, which are returned to the biosphere via precipitation, dry deposition and aerosols to close the biosphere-atmosphere nitrogen cycle. The sources, sinks and photochemistry/chemistry of the nitrogen species; atmospheric nitrogen species; souces and sinks of nitrous oxide; sources; sinks and photochemistry/chemistry of ammonia; seasonal variation of the vertical distribution of ammonia in the troposphere; surface and atmospheric sources of the nitrogen species, and seasonal variation of ground level ammonia are summarized.

The importance of fuel properties in the formation of nitrogen oxides and in combustion

International Nuclear Information System (INIS)

Huotari, J.; Aho, M.; Haemaelaeinen, J.; Huotari, J.; Saastamoinen, J.; Rantanen, J.

1995-01-01

The goal of this work is to find new information about the effects of pressure, temperature and fuel properties (Fuel-O/Fuel-N) on the formation of nitrogen oxides through the most important intermediates (NH 3 and HCN). In addition, a single particle model for the simultaneous pyrolysis and char combustion will be improved to be used for calculating combustion under pressure. Experimental work is done with an electrically heated pressurized entrained flow reactor (PEFR) which is equipped with modern analytics (as FT-IR for the analysis of N 2 O, NO and NO 2 and FT-IR pyrometry for the measurement of particle temperatures). The experimental work is carried out in several stages: (a) Study of the formation of HCN and NH 3 during pressurized pyrolysis (b) Oxidation of HCN and NH 3 to nitrogen oxides in pressurized combustion (c) Reduction of NO by NH 3 under pressure (thermax denox) Task a is performed with fuels of various O/N ratio. Task b is performed with pure HCN and NH 3 and with more complicated gas mixtures including HCN and NH 3 . A large part of these results are utilized in kinetic modelling in Aabo Akademi University, Finland in project LIEKKI 2-201. Two kinds of modelling work is performed in VTT in this project (a) Simultaneous modelling of the composition of solid and gaseous phases in the pyrolysis and combustion of a small fuel particle (multiphase modelling) (b) Modelling of pyrolysis and combustion of a single fuel particle under pressurized conditions (single particle modelling). The results can be used in planning of pressurized combustors and in minimizing the emissions of nitrogen oxides. (author)

Modelling of nitrogen oxides distribution in the hearth of gas-fired industrial furnace

Science.gov (United States)

Zhubrin, S.; Glazov, V.; Guzhov, S.

2017-11-01

A model is proposed for calculating the formation and transportation of nitrogen oxides in the combustion chamber of an industrial furnace heated by gaseous fuels burning. The calculations use a three-dimensional stationary description of turbulent flow and mixing of fuel and oxidizer flows in the presence of heat transfer, mass transfer, and momentum between them transfer. Simulation of the spatial pattern of nitrogen oxides formation in the working space of the furnace is performed in the programming and computing suite SCAN. It is shown that the temperature non-uniformity over the hearth surface is not too pronounced due to the organization of the inclined flow inlet in the direction of the hearth, which is a desirable feature of the furnace operation. The highest concentration of combustion products is observed in the zone of maximum temperatures. In addition, the existence of two zones of the highest generation of oxides has been determined. The first zone is located approximately in the center of the hearth, and the second is located on the far external surface of the furnace. The possibility of using the developed model in the SCAN complex for carrying out parametric studies and engineering calculations, as well as for modification in the direction of adjusting and adapting the model to the regime-constructive features of specific energy technological devices, is noted.

High electrocatalytic performance of nitrogen-doped carbon nanofiber-supported nickel oxide nanocomposite for methanol oxidation in alkaline medium

Energy Technology Data Exchange (ETDEWEB)

Al-Enizi, Abdullah M. [Department of Chemistry, King Saud University, PO Box: 2455, Riyadh 11451 (Saudi Arabia); Elzatahry, Ahmed A., E-mail: aelzatahry@ksu.edu.sa [Materials Science and Technology Program, College of Arts and Science, Qatar University, Doha 2713 (Qatar); Advanced Technology and New Materials Research Institute, City of Scientific Research and Technology Applications, New Borg El-Arab City, Alexandria 21934 (Egypt); Abdullah, Aboubakr M., E-mail: bakr@qu.edu.qa [Center for Advanced Materials, Qatar University, Doha 2713 (Qatar); Vinu, Ajayan [Future Industries Institute, University of South Australia, Building X-X2-09, Mawson Lakes Campus, Mawson Lakes 5095 SA (Australia); Iwai, Hideo [Materials Analysis Station, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki, 305-0047 (Japan); Al-Deyab, Salem S. [Petrochemical Research Chair, Department of Chemistry, King Saud University, PO Box: 2455, Riyadh 11451 (Saudi Arabia)

2017-04-15

Highlights: • A mixture of Polyvinylpyrrolidone (PVP), graphene and emeraldine base polyaniline (PANi) was electrospun and used as starting materials to prepare a nitrogen-doped carbon nanofiber (N-CNF). • Nickel oxide was loaded on the N-CNF to form a nanocomposite which was calcined later at different temperatures. • The effect of calcination temperature on the electrocatalytic behavior of the nanocomposite was studied which shows that the nanocomposite calcined at 500 °C was proved to be very high compared to the other calcination temperatures. • The stability of catalyst was excellent and its resistance to the adsorption of the intermediates generated from the methanol oxidation was very high. - Abstract: Nitrogen-Doped Carbon Nanofiber (N-CNF)–supported NiO composite was prepared by electrospinning a sol-gel mixture of graphene and polyaniline (PANi) with aqueous solutions of Polyvinylpyrrolidone (PVP) followed by a high-temperature annealing process. The electrospun was stabilized for 2 h at 280 °C, carbonized for 5 h at 1200 °C then loaded by 10% NiO. The electrocatalytic activities of the produced nanocomposite have been studied using cyclic voltammetry, and chronoamperometry. Also, N-CNF was characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), surface area (BET), X-ray photoelectron spectroscopy (XPS), transmission electron microscope (TEM), and scanning-electron microscopy (SEM). The obtained N-doped carbon nanofiber was found to have a nitrogen content of 2.6 atomic% with a diameter range of (140–160) nm, and a surface area (393.3 m{sup 2} g{sup −1}). In addition, it showed a high electrocatalytic behavior towards methanol oxidation reaction in alkaline medium and high stability and resistivity to the adsorption of intermediates.

Nitrogen inversion barriers affect the N-oxidation of tertiary alkylamines by cytochromes P450

DEFF Research Database (Denmark)

Rydberg, Patrik; Jørgensen, Martin S.; Jacobsen, T.A.

2013-01-01

Calculations: Cytochrome P450 enzymes facilitate a number of chemically different reactions. For example, amines can be either N-dealkylated or N-oxidized, but it is complex to rationalize which of these competing reactions occurs. It is shown that the barrier for inversion of the alkylamine...... nitrogen atom seems to be of vital importance for the amount of N-oxidized product formed relative to dealkylation and hydroxylation products....

Formation of Nitrogen Oxides in an Apokamp-Type Plasma Source

Science.gov (United States)

Sosnin, É. A.; Goltsova, P. A.; Panarin, V. A.; Skakun, V. S.; Tarasenko, V. F.; Didenko, M. V.

2017-08-01

Using optical and chemical processes, the composition of the products of decay of the atmospheric-pressure non-equilibrium plasma is determined in a pulsed, high-voltage discharge in the modes of apokampic and corona discharges. It is shown that the products of decay primarily contain nitrogen oxides NO x, and in the mode of the corona discharge - ozone. Potential applications of this source of plasma are discussed with respect to plasma processing of the seeds of agricultural crops.

Massive nitrogen loss from the Benguela upwelling system through anaerobic ammonium oxidation RID B-8834-2011

DEFF Research Database (Denmark)

Kuypers, MMM; Lavik, G.; Woebken, D.

2005-01-01

) and is commonly attributed to denitrification (reduction of nitrate to N-2 by heterotrophic bacteria). Here, we show that instead, the anammox process (the anaerobic oxidation of ammonium by nitrite to yield N-2) is mainly responsible for nitrogen loss in the OMZ waters of one of the most productive regions......In many oceanic regions, growth of phytoplankton is nitrogen-limited because fixation of N-2 cannot make up for the removal of fixed inorganic nitrogen (NH4+, NO2-, and NO3-) by anaerobic microbial processes. Globally, 30-50% of the total nitrogen loss occurs in oxygen-minimum zones (OMZs...... that anammox bacteria are responsible for massive losses of fixed nitrogen. We have identified and directly linked anammox bacteria to the removal of fixed inorganic nitrogen in the OMZ waters of an open-ocean setting. We hypothesize that anammox could also be responsible for substantial nitrogen loss from...

The characteristics of surface oxidation and corrosion resistance of nitrogen implanted zircaloy-4

International Nuclear Information System (INIS)

Tang, G.; Choi, B.H.; Kim, W.; Jung, K.S.; Kwon, H.S.; Lee, S.J.; Lee, J.H.; Song, T.Y.; Shon, D.H.; Han, J.G.

1997-01-01

This work is concerned with the development and application of ion implantation techniques for improving the corrosion resistance of zircaloy-4. The corrosion resistance in nitrogen implanted zircaloy-4 under a 120 keV nitrogen ion beam at an ion dose of 3 x 10 17 cm -2 depends on the implantation temperature. The characteristics of surface oxidation and corrosion resistance were analyzed with the change of implantation temperature. It is shown that as implantation temperature rises from 100 to 724 C, the colour of specimen surface changes from its original colour to light yellow at 100 C, golden at 175 C, pink at 300 C, blue at 440 C and dark blue at 550 C. As the implantation temperature goes above 640 C, the colour of surface changes to light black, and the surface becomes a little rough. The corrosion resistance of zircaloy-4 implanted with nitrogen is sensitive to the implantation temperature. The pitting potential of specimens increases from 176 to 900 mV (SCE) as the implantation temperature increases from 100 to 300 C, and decreases from 900 to 90 mV(SCE) as the implantation temperature increases from 300 to 640 C. The microstructure, the distribution of oxygen, nitrogen and carbon elements, the oxide grain size and the feature of the precipitation in the implanted surface were investigated by optical microscope, TEM, EDS, XRD and AES. The experimental results reveal that the ZrO 2 is distributed mainly on the outer surface. The ZrN is distributed under the ZrO 2 layer. The characteristics of the distribution of ZrO 2 and ZrN in the nitrogen-implanted zircaloy-4 is influenced by the implantation temperature of the sample, and in turn the corrosion resistance is influenced. (orig.)

Nitrogen-doped 3D reduced graphene oxide/polyaniline composite as active material for supercapacitor electrodes

Science.gov (United States)

Liu, Zhisen; Li, Dehao; Li, Zesheng; Liu, Zhenghui; Zhang, Zhiyuan

2017-11-01

A facile strategy for the fabrication of a nitrogen-doped 3D reduced graphene oxide (N-3D-rGO) macroporous structure is proposed in this paper. The proposed strategy used polystyrene microspheres as the templates and melamine as the nitrogen source. Using β-MnO2 as the oxidant, the as-prepared N-3D-rGO was then composited with polyaniline (PANI) nanowires (denoted as N-3D-rGO/PANI-B). The structure, morphology, and electrochemical properties of the composites were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, Brunauer-Emmett-Teller analysis, scanning electron microscopy, transmission electron microscopy, cyclic voltammetry, charge-discharge test, and electrochemical impedance spectroscopy. Results revealed that the N-3D-rGO/PANI-B composite has a better specific capacity than the composites prepared with 3D-rGO as the support material and peroxydisulfate as the oxidant. These results suggested that N-3D-rGO/PANI-B has potential applications in supercapacitors.

Nitrogen management impacts nitrous oxide emissions under varying cotton irrigation systems in the American Desert Southwest

Science.gov (United States)

Irrigation of food and fiber crops worldwide continues to increase. Nitrogen (N) from fertilizers is a major source of the potent greenhouse gas nitrous oxide (N2O) in irrigated cropping systems. Nitrous oxide emissions data are scarce for crops in the arid Western US. The objective of these studies...

Study of the Chemistry of Coordination of Oxide-anions of Nitrogen with Species of Iron and Copper as Models of Enzymes of the Cycle of the Nitrogen

International Nuclear Information System (INIS)

Quesada Espinoza, F

2001-01-01

In the present work, a study is carried out about the reactivity of some nitrogen oxide-anions, like nitrite (NO 2 - ) and trioxide-dinitrate (N 2 O 3 2- ), besides nitric oxide (NO), with copper species, iron, and cobalt in their states of oxidation II, in presence of the binding spectator bispicen. The synthesis and characterization of the [Cu(bispicen)NO 2 ]BF 4 was obtained, which can help to consolidate some mechanisms, proposed for the action of the nitrite reductase. The Fe(bispicen)(NO 2 ) 2 was also characterized; this is the fourth compound that presents two nitrites coordinated to an iron (II) through nitrogen. It has the characteristic of possessing short connection distances, which gives it a special attractiveness, and it opens the possibility of studying a spin exchange [es

Measurement and modeling of ozone and nitrogen oxides produced by laser breakdown in oxygen-nitrogen atmospheres.

Science.gov (United States)

Gornushkin, Igor B; Stevenson, Chris L; Galbács, Gábor; Smith, Ben W; Winefordner, James D

2003-11-01

The production of ozone nad nitrogen oxides was studied during multiple laser breakdown in oxygen-nitrogen mixtures at atmospheric pressure. About 2000 laser shots at 10(10) W cm-2 were delivered into a sealed reaction chamber. The chamber with a long capillary was designed to measure absorption of O3, NO, and NO2 as a function of the number of laser shots. The light source for absorption measurements was the continuum radiation emitted by the plasma during the first 0.2 microsecond of its evolution. A kinetic model was developed that encompassed the principal chemical reactions between the major atmospheric components and the products of laser breakdown. In the model, the laser plasma was treated as a source of nitric oxide and atomic oxygen, whose rates of production were calculated using measured absorption by NO, NO2, and O3. The calculated concentration profiles for NO, NO2, and O3 were in good agreement with measured profiles over a time scale of 0-200 s. The steady-state concentration of ozone was measured in a flow cell in air. For a single breakdown in air, the estimated steady-state yield of ozone was 2 x 10(12) molecules, which agreed with the model prediction. This study can be of importance for general understanding of laser plasma chemistry and for elucidating the nature of spectral interferences and matrix effects that may take place in applied spectrochemical analysis.

Influence of inlet concentration and light intensity on the photocatalytic oxidation of nitrogen(II) oxide at the surface of Aeroxide® TiO2 P25

International Nuclear Information System (INIS)

Dillert, Ralf; Stötzner, Julia; Engel, Astrid; Bahnemann, Detlef W.

2012-01-01

Highlights: ► The photocatalytic oxidation of nitrogen(II) oxide at the TiO 2 surface was studied. ► The effect of the UV(A) light intensity on the reaction rate was evaluated. ► The effect of the NO concentration on the reaction rate was evaluated. ► A mechanistic model for the heterogeneous NO oxidation is presented. ► A rate law describing the influence of NO concentration and light intensity is given. - Abstract: Air pollution by nitrogen oxides represents a serious environmental problem in urban areas where numerous sources of these pollutants are concentrated. One approach to reduce the concentration of these air pollutants is the light-induced oxidation in the presence of molecular oxygen and a photocatalytically active building material, e.g., paints, roof tiles, or pavement stones. Herein, results of an investigation concerning the photocatalytic oxidation of nitrogen(II) oxide (NO) in the presence of molecular oxygen and UV(A) irradiated TiO 2 powder are presented. The standard operating procedure described in ISO 22197-1 which was developed to characterize the photocatalytic activity of air-cleaning products was successfully applied to determine the photocatalytic activity of a bare TiO 2 powder. The experimental data reveal that at the light intensity stipulated by the operation procedure the amount of NO removed from the gas phase by photocatalytic oxidation is strongly affected by small changes of this light intensity as well as of the NO concentration in the gas stream in the photoreactor. Therefore, these parameters have to be controlled very carefully. Based upon the experimental data obtained in this study a rate law for the photocatalytic NO oxidation inside the photoreactor is derived.

High-Resolution Electron Energy Loss Studies of Oxygen, Hydrogen, Nitrogen, Nitric Oxide, and Nitrous Oxide Adsorption on Germanium Surfaces.

Science.gov (United States)

Entringer, Anthony G.

The first high resolution electron energy loss spectroscopy (HREELS) studies of the oxidation and nitridation of germanium surfaces are reported. Both single crystal Ge(111) and disordered surfaces were studied. Surfaces were exposed to H, O_2, NO, N _2O, and N, after cleaning in ultra-high vacuum. The Ge surfaces were found to be non-reactive to molecular hydrogen (H_2) at room temperature. Exposure to atomic hydrogen (H) resulted hydrogen adsorption as demonstrated by the presence of Ge-H vibrational modes. The HREEL spectrum of the native oxide of Ge characteristic of nu -GeO_2 was obtained by heating the oxide to 200^circC. Three peaks were observed at 33, 62, and 106 meV for molecular oxygen (O_2) adsorbed on clean Ge(111) at room temperature. These peaks are indicative of dissociative bonding and a dominant Ge-O-Ge bridge structure. Subsequent hydrogen exposure resulted in a shift of the Ge-H stretch from its isolated value of 247 meV to 267 meV, indicative of a dominant +3 oxidation state. A high density of dangling bonds and defects and deeper oxygen penetration at the amorphous Ge surface result in a dilute bridge structure with a predominant +1 oxidation state for similar exposures. Molecules of N_2O decompose at the surfaces to desorbed N_2 molecules and chemisorbed oxygen atoms. In contrast, both oxygen and nitrogen are detected at the surfaces following exposure to NO molecules. Both NO and N_2O appear to dissociate and bond at the top surface layer. Molecular nitrogen (N_2) does not react with the Ge surfaces, however, a precursor Ge nitride is observed at room temperature following exposure to nitrogen atoms and ions. Removal of oxygen by heating of the NO-exposed surface to 550^circC enabled the identification of the Ge-N vibrational modes. These modes show a structure similar to that of germanium nitride. This spectrum is also identical to that of the N-exposed surface heated to 550^circC. Surface phonon modes of the narrow-gap semiconducting

A DFT analysis of the adsorption of nitrogen oxides on Fe-doped graphene, and the electric field induced desorption

Science.gov (United States)

Cortés-Arriagada, Diego; Villegas-Escobar, Nery

2017-10-01

Density functional theory calculations were carried out to study the adsorption and sensing properties of Fe-doped graphene nanosheets (FeG) toward nitrogen oxides (NO, NO2, and N2O). The results indicated the adsorption of nitrogen oxides is significantly increased onto FeG compared to pristine graphene, reaching adsorption energies of 1.1-2.2 eV, even with a high stability at room temperature. As a result of the larger charge transfer and strong chemical binding, the bandgap of the adsorbent-adsorbate systems is increased in up to 0.5 eV with respect to the free FeG, indicating that FeG is highly sensitive to nitrogen oxides. It was also evidenced the adsorption and sensing properties remain even in the presence of O2 currents for N2O, where a co-adsorption mechanism was analyzed. Besides, NO2 is capable to induce the largest magnetization of FeG. Finally, positive electric fields of at least 0.04 a.u. decrease the stability of the adsorbent-adsorbate interactions, inducing the desorption process. Therefore, FeG emerges as a promising low-dimensional material with excellent adsorption and sensing properties to be applied in solid state sensors of nitrogen oxides, where electric fields can be used as a strategy for the FeG reactivation in repetitive sensing applications.

Use of liquid chromatography for measuring atmospheric sulfur dioxide and nitrogen oxide

Energy Technology Data Exchange (ETDEWEB)

Benova, E

1973-02-01

A literature search to ascertain the applicability of liquid chromatography to the analysis of atmospheric sulfur dioxide and various oxides of nitrogen is reported. Simple or enriched samples can be analyzed. Plastic bags are recommended for preparation of simple samples; and a table of 18 plastic materials, their manufacturers, and pollutants to which they are inert is provided. Enriched samples can be prepared in chromatographic columns by adsorption methods. Tables are provided listing carriers, stationary phase materials, temperatures, carrier liquids (helium or nitrogen), column dimensions, and other data recommended for chromatographic tests of SO/sub 2/ and NOx. Because of its reactivity and tendency to polymerize, sulfur trioxide should be reduced to SO/sub 2/ prior to analysis.

Zeolite ZSM5 catalysts for abatement of nitrogen oxide

Energy Technology Data Exchange (ETDEWEB)

Ganemi, Bager

1999-07-01

Airborne pollutants from the combustion of fossil fuels are a global problem. Emission of nitrogen oxides (NO{sub x}) is increasing with the worldwide increase in the use of energy. Atmospheric and photochemical reactions link nitrogen oxides to hydrocarbons and tropospheric ozone. The emission of NO{sub x} has to be tackled urgently in order to limit the harmful effects of anthropogenic activity on the environment. The subject of this thesis is catalytic nitrogen oxide abatement through direct decomposition and reduction by methane over ion-exchanged zeolite ZSM5. The work covers catalytic conversion and surface intermediates, including correlations with the level of exchanged Cu{sup 2+} cations and Ni{sup 2+} or Pd{sup 2+} co-cations. Special attention is given to the aluminium content of the support and changes in structural parameters. It was found that NO{sub x} conversion over cation-exchanged ZSM5 is strongly influenced by the ion-exchange procedure and by the above material parameters. Characterization of Cu-ZSM5 reveals that approximately two molecules of water per Cu{sup 2+} ion desorb at temperatures between 150 and 350 Deg C, in addition to the conventional dehydration at lower temperatures. The desorbed water comes from the decomposition of Cu(OH){sub 2}. Decomposition of hydroxylated copper ions results in the formation Of Cu{sup 2+}-O-Cu{sup 2+} dimers, which are suggested to be the active sites for catalytic decomposition of NO. Acid sites are important for the dispersion of copper ions on the catalyst surface. Acid sites are also important for the interaction between copper species and the zeolite. Increased acidity leads to a stronger interaction between the exchanged cation and the framework, i.e. the exchanged cations become more resistant to mobility. The stronger bond between the exchanged cations and lattice oxygen also prevents dealumination of the catalyst and decreases the thermal expansion at higher temperatures. The temperature of

High-temperature interaction of low niobium oxides with carbon and nitrogen

International Nuclear Information System (INIS)

Lyubimov, V.D.; Alyamovskij, S.I.; Askarova, L.Kh.

1980-01-01

Presented are the results of investigation on the process of high-temperature interaction (1200-1300 deg C) of NbO 2 and NbO with carbon (in the helium medium) and nitrogen. The reaction between NbO 2 and carbon is successfully realized at 1300 deg C and involves two stages, viz. reduction of oxide by the mechanism of direct reduction and subsequent insertion of metalloid into the oxygen vacancies formed. As a result, on the base of the initial oxide a cubic phase is formed, its final composition at 1300 deg C corresponding to the formula NbCsub(0.74)Osub(0.28). Neither NbO monoxide, nor metal is detected in the reaction products under these conditions. Interaction of NbO 2 with carbon and nitrogen proceeds in the similar way. In this case, the oxygen vacancies formed are occupied by the atoms of the two metalloids the end-product of the reaction at 1300 deg C being oxycarbonitride NbCsub(0.30)Nsub(0.66)Osub(0.66). Intermediate products of the reaction between NbO and metalloids involve oxycarbide, oxynitride, or oxycarbonitride and dioxide of niobium, while the end products contain only a cubic phase [ru

Wisconsin's forest resources in 2004

Science.gov (United States)

Charles H. Perry

2006-01-01

Results of the 2000-2004 annual inventory of Wisconsin show about 16.0 million acres of forest land, more than 22.1 billion cubic feet of live volume on forest land, and nearly 593 million dry tons of all live aboveground tree biomass on timberland. Populations of jack pine budworm are increasing, and it remains a significant pest in Wisconsin forests. A complete...

Analyzer for measurement of nitrogen oxide concentration by ozone content reduction in gas using solid state chemiluminescent sensor

Science.gov (United States)

Chelibanov, V. P.; Ishanin, G. G.; Isaev, L. N.

2014-05-01

Role of nitrogen oxide in ambient air is described and analyzed. New method of nitrogen oxide concentration measurement in gas phase is suggested based on ozone concentration measurement with titration by nitrogen oxide. Research of chemiluminescent sensor composition is carried out on experimental stand. The sensor produced on the base of solid state non-activated chemiluminescent composition is applied as ozone sensor. Composition is put on the surface of polymer matrix with developed surface. Sensor compositions includes gallic acid with addition of rodamine-6G. Model of interaction process between sensor composition and ozone has been developed, main products appeared during reaction are identified. The product determining the speed of luminescense appearance is found. This product belongs to quinone class. Then new structure of chemiluminescent composition was suggested, with absence of activation period and with high stability of operation. Experimental model of gas analyzer was constructed and operation algorithm was developed. It was demonstrated that developed NO measuring instrument would be applied for monitoring purposes of ambient air. This work was partially financially supported by Government of Russian Federation, Grant 074-U01

Formation of reactive nitrogen oxides from urban grime photochemistry

Science.gov (United States)

Baergen, Alyson M.; Donaldson, D. James

2016-05-01

Impervious surfaces are ubiquitous in urban environments and constitute a substrate onto which atmospheric constituents can deposit and undergo photochemical and oxidative processing, giving rise to "urban grime" films. HNO3 and N2O5 are important sinks for NOx in the lower atmosphere and may be deposited onto these films, forming nitrate through surface hydrolysis. Although such deposition has been considered as a net loss of NOx from the atmosphere, there is increasing evidence that surface-associated nitrate undergoes further reaction. Here, we examine the gas phase products of the photochemistry of real, field-collected urban grime using incoherent broadband cavity-enhanced absorption spectroscopy (IBBCEAS). Gas phase nitrogen oxides are emitted upon illumination of grime samples and their production increases with ambient relative humidity (RH) up to 35 % after which the production becomes independent of RH. These results are discussed in the context of water uptake onto and evaporation from grime films.

Inhibition of methane oxidation in slurry surface crust by inorganic nitrogen

DEFF Research Database (Denmark)

Duan, Yun-Feng; Elsgaard, Lars; Petersen, Søren O

2013-01-01

Livestock slurry is an important source of methane (CH4). Depending on dry matter content, a floating crust may form where methane-oxidizing bacteria (MOB) and CH4 oxidation activity have been found, suggesting that surface crusts may reduce CH4 emissions from slurry. However, it is not known how...... MOB in this environment interact with inorganic nitrogen (N). We studied inhibitory effects of ammonium (NH4+), nitrate (NO3–) and nitrite (NO2–) on potential CH4 oxidation in a cattle slurry surface crust. Methane oxidation was assayed at salt concentrations up to 500 mM at 100 and 10,000 ppmv...... headspace CH4. First-order rate constants were used to evaluate the strength of inhibition. Nitrite was the most potent inhibitor, reducing methanotrophic activity by up to 70% at only 1 mM NO2–. MOB were least sensitive to NO3–, tolerating up to 30 mM NO3– at 100 ppmv CH4 and 50 mM NO3– at 10,000 ppmv CH4...

Furnace devices aerodynamics optimization for fuel combustion efficiency improvement and nitrogen oxide emission reduction

Science.gov (United States)

Volkov, E. P.; Prokhorov, V. B.; Arkhipov, A. M.; Chernov, S. L.; Kirichkov, V. S.; Kaverin, A. A.

2017-11-01

MPEI conducts researches on physical and mathematical models of furnace chambers for improvement of power-generation equipment fuel combustion efficiency and ecological safety. Results of these researches are general principles of furnace aerodynamics arrangement for straight-flow burners and various fuels. It has been shown, that staged combustion arrangement with early heating and igniting with torch distribution in all furnace volume allows to obtain low carbon in fly ash and nitrogen oxide emission and also to improve boiler operation reliability with expand load adjustment range. For solid fuel combustion efficiency improvement it is practical to use high-placed and strongly down-tilted straight-flow burners, which increases high-temperature zone residence time for fuel particles. In some cases, for this combustion scheme it is possible to avoid slag-tap removal (STR) combustion and to use Dry-bottom ash removal (DBAR) combustion with tolerable carbon in fly ash level. It is worth noting that boilers with STR have very high nitrogen oxide emission levels (1200-1800 mg/m3) and narrow load adjustment range, which is determined by liquid slag output stability, so most industrially-developed countries don’t use this technology. Final decision about overhaul of boiler unit is made with regard to physical and mathematical modeling results for furnace and zonal thermal calculations for furnace and boiler as a whole. Overhaul of boilers to provide staged combustion and straight-flow burners and nozzles allows ensuring regulatory nitrogen oxide emission levels and corresponding best available technology criteria, which is especially relevant due to changes in Russian environmental regulation.

The Technology of Nitrogen Oxide Emissions Reduction at Pulverized Coal Burning

Directory of Open Access Journals (Sweden)

Dunaevska, N.I.

2016-11-01

Full Text Available To assess the effectiveness of the influence of thermochemical preparation of anthracite on the formation of nitrogen oxides the three-dimensional numerical model of the TPP-210A boiler`s furnace for standard and modified burners was created. The calculation results are shown the decrease of NOx concentration across the height of the furnace and reduce of the unburnt coal for the modified burners in comparison with standard ones.

EVALUATION OF TIRE-DERIVED FUEL FOR USE IN NITROGEN OXIDE REDUCTION BY REBURNING

Science.gov (United States)

Tire-derived fuel (TDF) was tested in a small-scale (44 kW or 150,000 Btu/hr) combustor to determine its feasibility as a fuel for use in reburning for control of nitrogen oxide (NO). TDF was gravity-fed into upward flowing combustion gases from a primary natural gas flame doped ...

Experimental study of nitrogen oxides in the IRT-M reactor

International Nuclear Information System (INIS)

Brazovskij, I.I.; Doroshevich, V.N.; Gvozdev, A.A.; Nesterenko, V.B.; Trubnikov, V.P.

1982-01-01

A critical review of different approaches to the radiolysis study of nitrogen oxide under mixed radiation conditions of a nuclear reactor was presented. Loop reactor piant opereted following gas-liquid cycle. It was shown in the process of long experiment in the operating conditions that irreversible radiation-thermal decomposition of the coolant increases little with temperature and pressure and radioactivity of the coolant and thermophysical equipment was moderate. Numerous kinetic experiments were conducted on the ampoule plant wherein all coolant existed in the zone of ionizing radiation effect. Initial pressure in the ampoule plant was set in the range of 0.1-16 MPa, depending on conditions of the experiment, and temperature 200-500 deg C. Dosimetry of the ampoule was carried out by the radiolysis of nitrogen monoxide. The analysis of the radiolysis products was conducted utilizing gas chromatography method, coolant vapours were removed in the process of low-temperature condensation under - 70 deg C

Outcompeting nitrite-oxidizing bacteria in single-stage nitrogen removal in sewage treatment plants: a model-based study.

Science.gov (United States)

Pérez, Julio; Lotti, Tommaso; Kleerebezem, Robbert; Picioreanu, Cristian; van Loosdrecht, Mark C M

2014-12-01

This model-based study investigated the mechanisms and operational window for efficient repression of nitrite oxidizing bacteria (NOB) in an autotrophic nitrogen removal process. The operation of a continuous single-stage granular sludge process was simulated for nitrogen removal from pretreated sewage at 10 °C. The effects of the residual ammonium concentration were explicitly analyzed with the model. Competition for oxygen between ammonia-oxidizing bacteria (AOB) and NOB was found to be essential for NOB repression even when the suppression of nitrite oxidation is assisted by nitrite reduction by anammox (AMX). The nitrite half-saturation coefficient of NOB and AMX proved non-sensitive for the model output. The maximum specific growth rate of AMX bacteria proved a sensitive process parameter, because higher rates would provide a competitive advantage for AMX. Copyright © 2014 Elsevier Ltd. All rights reserved.

Wisconsin Inventors` Network Database final report

Energy Technology Data Exchange (ETDEWEB)

1991-12-04

The Wisconsin Innovation Service Center at UW-Whitewater received a DOE grant to create an Inventor`s Network Database to assist independent inventors and entrepreneurs with new product development. Since 1980, the Wisconsin Innovation Service Center (WISC) at the University of Wisconsin-Whitewater has assisted independent and small business inventors in estimating the marketability of their new product ideas and inventions. The purpose of the WISC as an economic development entity is to encourage inventors who appear to have commercially viable inventions, based on preliminary market research, to invest in the next stages of development, perhaps investigating prototype development, legal protection, or more in-depth market research. To address inventor`s information needs, WISC developed on electronic database with search capabilities by geographic region and by product category/industry. It targets both public and private resources capable of, and interested in, working with individual and small business inventors. At present, the project includes resources in Wisconsin only.

Nursing Quality Assurance: The Wisconsin System

Science.gov (United States)

Hover, Julie; Zimmer, Marie J.

1978-01-01

Evaluation model guidelines for hospital departments of nursing to use in their nursing quality assurance programs are presented as developed in Wisconsin. Four essential components of the Wisconsin outcome evaluation system are criteria, assessment, standards, and improvement of care. Sample tests and charts are included in the article. (MF)

Rapid cycling of reactive nitrogen in the marine boundary layer.

Science.gov (United States)

Ye, Chunxiang; Zhou, Xianliang; Pu, Dennis; Stutz, Jochen; Festa, James; Spolaor, Max; Tsai, Catalina; Cantrell, Christopher; Mauldin, Roy L; Campos, Teresa; Weinheimer, Andrew; Hornbrook, Rebecca S; Apel, Eric C; Guenther, Alex; Kaser, Lisa; Yuan, Bin; Karl, Thomas; Haggerty, Julie; Hall, Samuel; Ullmann, Kirk; Smith, James N; Ortega, John; Knote, Christoph

2016-04-28

Nitrogen oxides are essential for the formation of secondary atmospheric aerosols and of atmospheric oxidants such as ozone and the hydroxyl radical, which controls the self-cleansing capacity of the atmosphere. Nitric acid, a major oxidation product of nitrogen oxides, has traditionally been considered to be a permanent sink of nitrogen oxides. However, model studies predict higher ratios of nitric acid to nitrogen oxides in the troposphere than are observed. A 'renoxification' process that recycles nitric acid into nitrogen oxides has been proposed to reconcile observations with model studies, but the mechanisms responsible for this process remain uncertain. Here we present data from an aircraft measurement campaign over the North Atlantic Ocean and find evidence for rapid recycling of nitric acid to nitrous acid and nitrogen oxides in the clean marine boundary layer via particulate nitrate photolysis. Laboratory experiments further demonstrate the photolysis of particulate nitrate collected on filters at a rate more than two orders of magnitude greater than that of gaseous nitric acid, with nitrous acid as the main product. Box model calculations based on the Master Chemical Mechanism suggest that particulate nitrate photolysis mainly sustains the observed levels of nitrous acid and nitrogen oxides at midday under typical marine boundary layer conditions. Given that oceans account for more than 70 per cent of Earth's surface, we propose that particulate nitrate photolysis could be a substantial tropospheric nitrogen oxide source. Recycling of nitrogen oxides in remote oceanic regions with minimal direct nitrogen oxide emissions could increase the formation of tropospheric oxidants and secondary atmospheric aerosols on a global scale.

chemical kinetic study of nitrogen oxides formation in methane flameless combustion

International Nuclear Information System (INIS)

Alvarado T, Pedro N; Cadavid S, Francisco; Mondragon, P Fanor; Ruiz, Wilson

2009-01-01

The present paper deals with the nitrogen oxides formation in a flameless combustion process characterized for using air highly diluted and preheated at high temperatures. The combustion model used in this study was the one dimensional counterflow methane air diffusion flame. The NOx production rate analysis showed that the thermal and prompt mechanisms are the most important for the formation and consumption of NO under dilution conditions for the oxidant in N 2 and combustion products. These mechanisms are related since the starting reaction for NO formation (N2 molecular dissociation) belongs to the prompt mechanism while the NO formation is reported mainly for the thermal mechanism reactions. On the other hand, the NO - NO 2 equilibrium showed that the reaction rates are comparable to that obtained by the thermal and prompt mechanisms, but its global contribution to NO formation are almost insignificant due to the oxidation reaction with radicals HO 2 .

Adsorption/oxidation of sulfur-containing gases on nitrogen-doped activated carbon

Directory of Open Access Journals (Sweden)

Liu Qiang

2016-01-01

Full Text Available Coconut shell-based activated carbon (CAC was used for the removal of methyl mercaptan (MM. CAC was modified by urea impregnation and calcined at 450°C and 950°C. The desulfurization activity was determined in a fixed bed reactor under room temperature. The results showed that the methyl mercaptan adsorption/oxidation capacity of modified carbon caicined at 950°C is more than 3 times the capacity of original samples. On the other hand, the modified carbon caicined at 950°C also has a high capacity for the simultaneous adsorption/oxidation of methyl mercaptan and hydrogen sulfide.The introduce of basic nitrogen groups siginificantly increases the desulfurization since it can facilitate the electron transfer process between sulfur and oxygen. The structure and chemical properties are characterized using Boehm titration, N2 adsorption-desorption method, thermal analysis and elemental analysis. The results showed that the major oxidation products were dimethyl disulfide and methanesulfonic acid which adsorbed in the activated carbon.

Catalyst and method for reduction of nitrogen oxides

Science.gov (United States)

Ott, Kevin C [Los Alamos, NM

2008-05-27

A Selective Catalytic Reduction (SCR) catalyst was prepared by slurry coating ZSM-5 zeolite onto a cordierite monolith, then subliming an iron salt onto the zeolite, calcining the monolith, and then dipping the monolith either into an aqueous solution of manganese nitrate and cerium nitrate and then calcining, or by similar treatment with separate solutions of manganese nitrate and cerium nitrate. The supported catalyst containing iron, manganese, and cerium showed 80 percent conversion at 113 degrees Celsius of a feed gas containing nitrogen oxides having 4 parts NO to one part NO.sub.2, about one equivalent ammonia, and excess oxygen; conversion improved to 94 percent at 147 degrees Celsius. N.sub.2O was not detected (detection limit: 0.6 percent N.sub.2O).

Enhanced detection of nitrogen dioxide via combined heating and pulsed UV operation of indium oxide nano-octahedra

Directory of Open Access Journals (Sweden)

Oriol Gonzalez

2016-10-01

Full Text Available We report on the use of combined heating and pulsed UV light activation of indium oxide gas sensors for enhancing their performance in the detection of nitrogen dioxide in air. Indium oxide nano-octahedra were synthesized at high temperature (900 °C via vapour-phase transport and screen-printed onto alumina transducers that comprised interdigitated electrodes and a heating resistor. Compared to the standard, constant temperature operation of the sensor, mild heating (e.g., 100 °C together with pulsed UV light irradiation employing a commercially available, 325 nm UV diode (square, 1 min period, 15 mA drive current signal, results in an up to 80-fold enhancement in sensitivity to nitrogen dioxide. Furthermore, this combined operation method allows for making savings in power consumption that range from 35% to over 80%. These results are achieved by exploiting the dynamics of sensor response under pulsed UV light, which convey important information for the quantitative analysis of nitrogen dioxide.

Enhanced detection of nitrogen dioxide via combined heating and pulsed UV operation of indium oxide nano-octahedra.

Science.gov (United States)

Gonzalez, Oriol; Roso, Sergio; Vilanova, Xavier; Llobet, Eduard

2016-01-01

We report on the use of combined heating and pulsed UV light activation of indium oxide gas sensors for enhancing their performance in the detection of nitrogen dioxide in air. Indium oxide nano-octahedra were synthesized at high temperature (900 °C) via vapour-phase transport and screen-printed onto alumina transducers that comprised interdigitated electrodes and a heating resistor. Compared to the standard, constant temperature operation of the sensor, mild heating (e.g., 100 °C) together with pulsed UV light irradiation employing a commercially available, 325 nm UV diode (square, 1 min period, 15 mA drive current signal), results in an up to 80-fold enhancement in sensitivity to nitrogen dioxide. Furthermore, this combined operation method allows for making savings in power consumption that range from 35% to over 80%. These results are achieved by exploiting the dynamics of sensor response under pulsed UV light, which convey important information for the quantitative analysis of nitrogen dioxide.

Deposition and surface characterization of nanoparticles of zinc oxide using dense plasma focus device in nitrogen atmosphere

International Nuclear Information System (INIS)

Malhotra, Yashi; Srivastava, M P; Roy, Savita

2010-01-01

Nanoparticles of zinc oxide from zinc oxide pellets in the nitrogen plasma atmosphere are deposited on n and p type silicon substrates using Dense Plasma Focus device. The hot and dense nitrogen plasma formed during the focus phase ionizes the ZnO pellet, which then move upward in a fountain like shape and gets deposited on substrates which are placed above the top of the anode. Structural and surface properties of the deposited ZnO are investigated using X-ray diffraction and Atomic force microscope (AFM). X-ray spectra shows the diffraction plane (002) of ZnO nanoparticles deposited on Si with few shots in nitrogen atmosphere. AFM investigations revealed that there are nanoparticles of size between 15-80 nm on n-Si and p-Si substrates. The deposition on n-type Si is better than the p-type Si can be seen from AFM images, this may be due to different orientation of silicon.

Synthesis of honeycomb-like mesoporous nitrogen-doped carbon nanospheres as Pt catalyst supports for methanol oxidation in alkaline media

Science.gov (United States)

Zhang, Yunmao; Liu, Yong; Liu, Weihua; Li, Xiying; Mao, Liqun

2017-06-01

This paper reports the convenient synthesis of honeycomb-like mesoporous nitrogen-doped carbon spheres (MNCS) using a self-assembly strategy that employs dopamine (DA) as a carbon and nitrogen precursor and a polystyrene-b-poly(ethylene oxide) (PS173-b-PEO170) diblock copolymer as a soft template. The MNCS have large BET surface areas of up to 554 m2 g-1 and high nitrogen contents of up to 6.9 wt%. The obtained MNCS are used as a support for Pt catalysts, which promote methanol oxidation in alkaline media. The MNCS-supported Pt (Pt/MNCS) catalyst has a larger electrochemically active surface area (ESA) (89.2 m2 g-1) than does a commercially available Vulcan XC-72R supported Pt/C catalyst. Compared to the Pt/C catalyst, Pt/MNCS displays a higher peak current density (1007 mA mg-1) and is more stable during methanol oxidation. These improvements are attributed to the honeycomb-like porous structure of the MNCS and the introduction of nitrogen to the carbon support. The MNCS effectively stabilize Pt nanoparticles and assuage the agglomeration of the nanoparticles, suggesting that MNCS are potential and promising application as electrocatalyst supports in alkaline direct methanol fuel cells.

Within-city contrasts in PM composition and sources and their relationship with nitrogen oxides.

Science.gov (United States)

Minguillón, M C; Rivas, I; Aguilera, I; Alastuey, A; Moreno, T; Amato, F; Sunyer, J; Querol, X

2012-10-26

The present work is part of the INMA (INfancia y Medio Ambiente -'Environment and Childhood') project, which aims at assessing the adverse effects of exposure to air pollution during pregnancy and early in life. The present study was performed in the city of Sabadell (Northeast Spain) at three sampling sites covering different traffic characteristics, during two times of the year. It assesses time and spatial variations of PM(2.5) concentrations, chemical components and source contributions, as well as gaseous pollutants. Furthermore, a cross-correlation analysis of PM components and source contributions with gaseous pollutants used as a proxy for exposure assessment is carried out. Our data show the influence of traffic emissions in the Sabadell area. The main PM sources identified by Positive Matrix Factorisation (PMF) were similar between the two seasons: mineral source (traffic-induced resuspension, demolition/construction and natural background), secondary sulphate (higher in summer), secondary nitrate (only during winter), industrial, and road traffic, which was the main contributor to PM(2.5) at two of the sites. The correlation of concentrations of nitrogen oxides was especially strong with those of elemental carbon (EC). The relatively weaker correlations with organic carbon (OC) in summer are attributed to the variable formation of secondary OC. Strong correlations between concentration of nitrogen oxides and PM(2.5) road traffic contributions obtained from source apportionment analysis were seen at all sites. Therefore, under the studied urban environment, nitrogen oxides can be used as a proxy for the exposure to road traffic contribution to PM(2.5); the use of NO(x) concentrations being preferred, with NO and NO(2) as second and third options, respectively.

Emission of nitrogen oxides from small biomass-fired grate boilers - a literature survey

International Nuclear Information System (INIS)

Olsson, Daniel

1999-05-01

A literature study has been carried out to find mechanisms for control of nitrogen oxide emissions from small-scale biomass fired combustion devices. The underlying nitrogen chemistry has been studied. Three paths of nitrogen oxide formation has been identified: 1. Thermal NO x , 2, Prompt NO x , and, 3. Fuel NO x . Out of these three mechanisms only fuel NO x is of interest, and the others are neglected at the temperature level concerned. The results from this study have been used to identify limitations and possibilities for NO x and CO abatement. A beacon has been to find efficient methods for NO x abatement at the same time as complete burn-out of the fuel is of greatest importance. The NO x abatement work of many of the Swedish manufacturers of small-scale combustion devices is described. This gives valuable insight in the practical possibilities and limitations in strive for low NOx emissions. From the literature and the contacts with manufacturers some factors of great importance for NO x emission control have been identified. These are: * The fuel (nitrogen content, shape, size, the height of the fuel layer and the tendency of the fuel to stick), * The stoichiometry in the volume above the fuel bed (should be 0.6 - 0.8), * The mixing of the gases above the fuel bed, * The mixing of tertiary air into the main gas flow, and * The thermal load of the combustion chamber (residence time). All the secondary measures studied but selective catalytic reduction have been rejected. Selective catalytic reduction could be a possible solution to the NO x emission problem if it is necessary to further lower the emissions from these small-scale biomass combustion devices despite the cost Project report from the program: Small scale combustion of biofuels. 22 refs, 30 figs, 4 tabs

Nitrogen oxide suppression by using a new design of pulverized-coal burners

Energy Technology Data Exchange (ETDEWEB)

Kotler, V.R.; Cameron, S.D.; Grekhov, L.L. [All-Russian Thermal Engineering Institute, Moscow (Russian Federation)

1996-07-01

The results of testing a low-NO{sub x} swirl burner are presented. This burner was developed by Babcock Energy Ltd., for reducing nitrogen oxide emissions when burning Ekibastuz and Kuznetsk low-caking coals in power boilers. The tests conducted at a large plant of the BEL Technological Center showed that the new burner reduces NO{sub x} emissions by approximately two times. 6 refs., 6 figs., 1 tab.

Graphene oxide quantum dot-derived nitrogen-enriched hybrid graphene nanosheets by simple photochemical doping for high-performance supercapacitors

Science.gov (United States)

Xu, Yongjie; Li, Xinyu; Hu, Guanghui; Wu, Ting; Luo, Yi; Sun, Lang; Tang, Tao; Wen, Jianfeng; Wang, Heng; Li, Ming

2017-11-01

Nitrogen-enriched graphene was fabricated via a facile strategy. Graphene oxide (GO) nanosheets and graphene oxide quantum dots (GQDs) were used as a structure-directing agent and in situ activating agent, respectively, after photoreduction under NH3 atmosphere. The combination of photoreduction and NH3 not only reduced GO and GQD composites (GO/GQDs) within a shorter duration but also doped a high level of nitrogen on the composites (NrGO/GQDs). The nitrogen content of NrGO/GQDs reached as high as 18.86 at% within 5 min of irradiation. Benefiting from the nitrogen-enriched GO/GQDs hybrid structure, GQDs effectively prevent the agglomeration of GO sheets and increased the numbers of ion channels in the material. Meanwhile, the high levels of nitrogen improved electrical conductivity and strengthened the binding energy between GQD and GO sheets. Compared with reduced GO and low nitrogen-doped reduced GO, NrGO/GQD electrodes exhibited better electrochemical characteristics with a high specific capacitance of 344 F g-1 at a current density of 0.25 A g-1. Moreover, the NrGO/GQD electrodes exhibited 82% capacitance retention after 3000 cycles at a current density of 0.8 A g-1 in 6 M KOH electrolyte. More importantly, the NrGO/GQD electrodes deliver a high energy density of 43 Wh kg-1 at a power density of 417 W kg-1 in 1 M Li2SO4 electrolyte. The nitrogen-doped graphene and corresponding supercapacitor presented in this study are novel materials with potential applications in advanced energy storage systems.

Evaluation on nitrogen oxides and nanoparticle removal and nitrogen monoxide generation using a wet-type nonthermal plasma reactor

Science.gov (United States)

Takehana, Kotaro; Kuroki, Tomoyuki; Okubo, Masaaki

2018-05-01

Nitrogen oxides (NOx) emitted from power plants and combustion sources cause air pollution problems. Selective catalytic reduction technology is remarkably useful for NOx removal. However, there are several drawbacks such as preparation of reducing agents, usage of harmful heavy metals, and higher cost. On the other hand, trace NO is a vasodilator agent and employed in inhalation therapies for treating pulmonary hypertension in humans. Considering these factors, in the present study, a wet-type nonthermal plasma reactor, which can control NOx and nanoparticle emissions and generate NO, is investigated. The fundamental characteristics of the reactor are investigated. First, the experiment of nanoparticle removal is carried out. Collection efficiencies of over 99% are achieved for nanoparticles at 50 and 100 ml min‑1 of liquid flow rates. Second, experiments of NOx removal under air atmosphere and NOx generation under nitrogen atmosphere are carried out. NOx-removal efficiencies of over 95% under the air plasma are achieved in 50–200 ml min‑1 liquid flow rates. Moreover, under nitrogen plasma, NOx is generated, of which the major portion is NO. For example, NO concentration is 25 ppm, while NOx concentration is 31 ppm at 50 ml min‑1 liquid flow rate. Finally, experiments of NO generation under the nitrogen atmosphere with or without flowing water are carried out. When water flows on the inner surface of the reactor, approximately 14 ppm of NO is generated. Therefore, NO generation requires flowing water. It is considered that the reaction of N and OH, which is similar to the extended Zeldovich mechanism, could occur to induce NO formation. From these results, it is verified that the wet-type plasma reactor is useful for NOx removal and NO generation under nitrogen atmosphere with flowing water.

Extending the benchmark simulation model no2 with processes for nitrous oxide production and side-stream nitrogen removal

DEFF Research Database (Denmark)

Boiocchi, Riccardo; Sin, Gürkan; Gernaey, Krist V.

2015-01-01

In this work the Benchmark Simulation Model No.2 is extended with processes for nitrous oxide production and for side-stream partial nitritation/Anammox (PN/A) treatment. For these extensions the Activated Sludge Model for Greenhouse gases No.1 was used to describe the main waterline, whereas...... the Complete Autotrophic Nitrogen Removal (CANR) model was used to describe the side-stream (PN/A) treatment. Comprehensive simulations were performed to assess the extended model. Steady-state simulation results revealed the following: (i) the implementation of a continuous CANR side-stream reactor has...... increased the total nitrogen removal by 10%; (ii) reduced the aeration demand by 16% compared to the base case, and (iii) the activity of ammonia-oxidizing bacteria is most influencing nitrous oxide emissions. The extended model provides a simulation platform to generate, test and compare novel control...

Study on the use of oxidant scrubbers for elimination of interferences due to nitrogen dioxide in analysis of atmospheric dimethylsulfide

Directory of Open Access Journals (Sweden)

Rodrigues Beatriz A.

2000-01-01

Full Text Available In this work, oxidant scrubbers were evaluated for their ability to prevent sampling losses of dimethylsulfide caused by reactions with nitrogen dioxide. Various compounds and mixtures were used in the preparation of the oxidant scrubbers. An automatic flow analysis device was used to compare scrubbing efficiency for nitrogen dioxide. Among the scrubbers tested, the best were shown to be the one made with filter paper or glass wool coated with iron (II sulfate, sulfuric acid and pyrogallic acid, and the one made from with paper coated with triethanolamine. The results obtained under laboratory conditions, using dimethylsulfide standard gas, and in field experiments confirmed that these scrubbers are suitable for the prevention of oxidation during sampling.

Nitrous oxide fluxes and nitrogen cycling along a pasturechronosequence in Central Amazonia, Brazil

Science.gov (United States)

B. Wick; E. Veldkamp; W. Z. de Mello; M. Keller; P. Crill

2005-01-01

We studied nitrous oxide (N2O) fluxes and soil nitrogen (N) cycling following forest conversion to pasture in the central Amazon near Santarém, Pará, Brazil. Two undisturbed forest sites and 27 pasture sites of 0.5 to 60 years were sampled once each during wet and dry seasons. In addition to soil-atmosphere fluxes of N...

The origin of traps and the effect of nitrogen plasma in oxide-nitride-oxide structures for non-volatile memories

International Nuclear Information System (INIS)

Kim, W. S.; Kwak, D. W.; Oh, J. S.; Lee, D. W.; Cho, H. Y.

2010-01-01

Ultrathin oxide-nitride-oxide (ONO) dielectric stacked layers are fundamental structures of silicon-oxide-nitride-oxide-silicon (SONOS) non-volatile memory devices in which information is known to be stored as charges trapped in silicon nitride. Deep-level transient spectroscopy (DLTS) and a capacitance-voltage (CV) analysis were introduced to observe the trap behavior related to the memory effect in memory devices. The DLTS results verified that the nitride-related traps were a dominant factor in the memory effect. The energy of hole traps was 0.307 eV above the balance band. To improve the memory effects of the non-volatile memory devices with ONO structures, we introduced a nitrogen plasma treatment. After the N-plasma treatment, the flat-band voltage shift (ΔV FB ) was increased by about 1.5 times. The program and the erase (P-E) characteristics were also shown to be better than those for the as-ONO structure. In addition, the retention characteristics were improved by over 2.4 times.

Nitrous oxide emissions from a peatbog after 13 years of experimental nitrogen deposition

Directory of Open Access Journals (Sweden)

S. R. Leeson

2017-12-01

Full Text Available Nitrogen deposition was experimentally increased on a Scottish peatbog over a period of 13 years (2002–2015. Nitrogen was applied in three forms, NH3 gas, NH4Cl solution, and NaNO3 solution, at rates ranging from 8 (ambient to 64 kg N ha−1 yr−1, and higher near the NH3 fumigation source. An automated system was used to apply the nitrogen, such that the deposition was realistic in terms of rates and high frequency of deposition events. We measured the response of nitrous oxide (N2O flux to the increased nitrogen input. Prior expectations, based on the IPCC default emission factor, were that 1 % of the added nitrogen would be emitted as N2O. In the plots treated with NH4+ and NO3− solution, no response was seen, and there was a tendency for N2O fluxes to be reduced by additional nitrogen, though this was not significant. Areas subjected to high NH3 emitted more N2O than expected, up to 8.5 % of the added nitrogen. Differences in the response are related to the impact of the nitrogen treatments on the vegetation. In the NH4+ and NO3− treatments, all the additional nitrogen is effectively immobilised in the vegetation and top 10 cm of peat. In the NH3 treatment, much of the vegetation was killed off by high doses of NH3, and the nitrogen was presumably more available to denitrifying bacteria. The design of the wet and dry experimental treatments meant that they differed in statistical power, and we are less likely to detect an effect of the NH4+ and NO3− treatments, though they avoid issues of pseudo-replication.

Genome-Scale, Constraint-Based Modeling of Nitrogen Oxide Fluxes during Coculture of Nitrosomonas europaea and Nitrobacter winogradskyi

Science.gov (United States)

Giguere, Andrew T.; Murthy, Ganti S.; Bottomley, Peter J.; Sayavedra-Soto, Luis A.

2018-01-01

ABSTRACT Nitrification, the aerobic oxidation of ammonia to nitrate via nitrite, emits nitrogen (N) oxide gases (NO, NO2, and N2O), which are potentially hazardous compounds that contribute to global warming. To better understand the dynamics of nitrification-derived N oxide production, we conducted culturing experiments and used an integrative genome-scale, constraint-based approach to model N oxide gas sources and sinks during complete nitrification in an aerobic coculture of two model nitrifying bacteria, the ammonia-oxidizing bacterium Nitrosomonas europaea and the nitrite-oxidizing bacterium Nitrobacter winogradskyi. The model includes biotic genome-scale metabolic models (iFC578 and iFC579) for each nitrifier and abiotic N oxide reactions. Modeling suggested both biotic and abiotic reactions are important sources and sinks of N oxides, particularly under microaerobic conditions predicted to occur in coculture. In particular, integrative modeling suggested that previous models might have underestimated gross NO production during nitrification due to not taking into account its rapid oxidation in both aqueous and gas phases. The integrative model may be found at https://github.com/chaplenf/microBiome-v2.1. IMPORTANCE Modern agriculture is sustained by application of inorganic nitrogen (N) fertilizer in the form of ammonium (NH4+). Up to 60% of NH4+-based fertilizer can be lost through leaching of nitrifier-derived nitrate (NO3−), and through the emission of N oxide gases (i.e., nitric oxide [NO], N dioxide [NO2], and nitrous oxide [N2O] gases), the latter being a potent greenhouse gas. Our approach to modeling of nitrification suggests that both biotic and abiotic mechanisms function as important sources and sinks of N oxides during microaerobic conditions and that previous models might have underestimated gross NO production during nitrification. PMID:29577088

Genome-Scale, Constraint-Based Modeling of Nitrogen Oxide Fluxes during Coculture of Nitrosomonas europaea and Nitrobacter winogradskyi.

Science.gov (United States)

Mellbye, Brett L; Giguere, Andrew T; Murthy, Ganti S; Bottomley, Peter J; Sayavedra-Soto, Luis A; Chaplen, Frank W R

2018-01-01

Nitrification, the aerobic oxidation of ammonia to nitrate via nitrite, emits nitrogen (N) oxide gases (NO, NO 2 , and N 2 O), which are potentially hazardous compounds that contribute to global warming. To better understand the dynamics of nitrification-derived N oxide production, we conducted culturing experiments and used an integrative genome-scale, constraint-based approach to model N oxide gas sources and sinks during complete nitrification in an aerobic coculture of two model nitrifying bacteria, the ammonia-oxidizing bacterium Nitrosomonas europaea and the nitrite-oxidizing bacterium Nitrobacter winogradskyi . The model includes biotic genome-scale metabolic models (iFC578 and iFC579) for each nitrifier and abiotic N oxide reactions. Modeling suggested both biotic and abiotic reactions are important sources and sinks of N oxides, particularly under microaerobic conditions predicted to occur in coculture. In particular, integrative modeling suggested that previous models might have underestimated gross NO production during nitrification due to not taking into account its rapid oxidation in both aqueous and gas phases. The integrative model may be found at https://github.com/chaplenf/microBiome-v2.1. IMPORTANCE Modern agriculture is sustained by application of inorganic nitrogen (N) fertilizer in the form of ammonium (NH 4 + ). Up to 60% of NH 4 + -based fertilizer can be lost through leaching of nitrifier-derived nitrate (NO 3 - ), and through the emission of N oxide gases (i.e., nitric oxide [NO], N dioxide [NO 2 ], and nitrous oxide [N 2 O] gases), the latter being a potent greenhouse gas. Our approach to modeling of nitrification suggests that both biotic and abiotic mechanisms function as important sources and sinks of N oxides during microaerobic conditions and that previous models might have underestimated gross NO production during nitrification.

Nitrate and Nitrogen Oxides: Sources, Health Effects and Their Remediation.

Science.gov (United States)

Hakeem, Khalid Rehman; Sabir, Muhammad; Ozturk, Munir; Akhtar, Mohd Sayeed; Ibrahim, Faridah Hanum

Increased use of nitrogenous (N) fertilizers in agriculture has significantly altered the global N-cycle because they release nitrogenous gases of environmental concerns. The emission of nitrous oxide (N 2 O) contributes to the global greenhouse gas accumulation and the stratospheric ozone depletion. In addition, it causes nitrate leaching problem deteriorating ground water quality. The nitrate toxicity has been reported in a number of studies showing the health hazards like methemoglobinemia in infants and is a potent cause of cancer. Despite these evident negative environmental as well as health impacts, consumption of N fertilizer cannot be reduced in view of the food security for the teeming growing world population. Various agronomic and genetic modifications have been practiced to tackle this problem. Some agronomic techniques adopted include split application of N, use of slow-release fertilizers, nitrification inhibitors and encouraging the use of organic manure over chemical fertilizers. As a matter of fact, the use of chemical means to remediate nitrate from the environment is very difficult and costly. Particularly, removal of nitrate from water is difficult task because it is chemically non-reactive in dilute aqueous solutions. Hence, the use of biological means for nitrate remediation offers a promising strategy to minimize the ill effects of nitrates and nitrites. One of the important goals to reduce N-fertilizer application can be effectively achieved by choosing N-efficient genotypes. This will ensure the optimum uptake of applied N in a balanced manner and exploring the molecular mechanisms for their uptake as well as metabolism in assimilatory pathways. The objectives of this paper are to evaluate the interrelations which exist in the terrestrial ecosystems between the plant type and characteristics of nutrient uptake and analyze the global consumption and demand for fertilizer nitrogen in relation to cereal production, evaluate the various

Nitrogen oxidative activation in the radiolysis process of dioxide hydrocarbon composition, oxygen-nitrogen over 3-d transition metals

International Nuclear Information System (INIS)

Rustamov, V.R.; Garibov, A.A.; Kerimov, V.K.; Aliyev, S.M.; Nasirova, Kh.Y.

2004-01-01

The radiochemical process of nitrogen fixation in carbon dioxide, oxygen-nitrogen composition in 3-d metal (iron, nickel) was studied. Bifunctional character of surface's role in the generation of radiolysis products was postulated: a) Chemisorption's of molecular ions (N 2 + , CO 2 + , O 2 + ) on the surface of metal and their dissociative neutralization. b) Coordination of nitrogen and carbon oxide being generated in nitrosyl and carbonyl-nitrosyl complex of iron and nickel. Total yield of the products is over the rang 6,4†7,5, to explain radiolysis' what contribution of only neutral products is impossible. Evidently in the generation of final products, defined contribution brings in molecular ions N 2 + (N + ) and CO 2 + . Interaction character of these ions with nickel proposes the formation of the relation between unpaired electrons N 2 + and CO 2 + with unfilled d-sub level of this metals with the nickel nitride generation [N i -N=N + ] and binding energy in ion diazotate decreases to twice. The yield of nitrogen dioxide on radiolysis of the air gave G NO2 =0,8±0,2 molecule/100eV which is proper to the date in the literature. Kinetic curve appears rapidly in the saturation. Air radiolysis over iron gave the following results: G NO 2 = 2,75 ± 0,25, G N 2 O = 9,0 ± 1,0 molecule/100eV. Thus total yield of radiolysis products is Σ G = 10,5 ± 12,0 molecule/100eV. (author)

Nitrogen oxidative activation in the radiolysis process of dioxide hydrocarbon composition, oxygen-nitrogen over 3-D transition metals

International Nuclear Information System (INIS)

Rustamov, V.R.; Garibov, A.A.; Kerimov, V.K.; Aliyev, S.M.; Nasirova, Kh.Y.

2004-01-01

Full text: The radiochemical process of nitrogen fixation in carbon dioxide, oxygen-nitrogen composition in 3-d metal (iron, nickel) was studied. Bifunctional character of surface's role in the generation of radiolysis products was postulated: a) Chemisorption's of molecular ions (N 2 + , CO 2 + , O 2 + ) on the surface of metal and their dissociative neutralization. b) Coordination of nitrogen and carbon oxide being generated in nitrosyl and carbonyl-nitrosyl complex of iron and nickel. Total yield of the products is over the rang 6,4†7,5, to explain radiolysis' what contribution of only neutral products is impossible. Evidently in the generation of final products, defined contribution brings in molecular ions N 2 + (N + ) and CO 2 + . Interaction character of these ions with nickel proposes the formation of the relation between unpaired electrons N 2 + and CO 2 + with unfilled d-sub level of this metals with the nickel nitride generation [N i -N=N + ] and binding energy in ion diazotate decreases to twice. The yield of nitrogen dioxide on radiolysis of the air gave G NO2 =0,8±0,2 molecule/100eV which is proper to the date in the literature. Kinetic curve appears rapidly in the saturation. Air radiolysis over iron gave the following results: G NO 2 = 2,75 ± 0,25, G N 2 O = 9,0 ± 1,0 molecule/100eV. Thus total yield of radiolysis products is Σ G = 10,5 ± 12,0 molecule/100eV

New levy on nitrogen oxide emissions: First 'refundable' pollution charge

International Nuclear Information System (INIS)

Andersson, Sus; Hanneberg, P.

1991-01-01

A new law imposing a charge on nitrogen oxide emissions from combustion installations will soon be coming into force in Sweden. The money generated by the charge will not stay in the exchequer, however, but will be repaid to the plants concerned in proportion to the amount of useful energy they produce. This will be the first environment levy in Sweden to be based on measurements of actual emissions. Emissions of sulphur and carbon dioxide are already taxed. These taxes, unlike other environmental charges, not only have an incentive function, but are also a source of income for the state

Influence of inlet concentration and light intensity on the photocatalytic oxidation of nitrogen(II) oxide at the surface of Aeroxide{sup Registered-Sign} TiO{sub 2} P25

Energy Technology Data Exchange (ETDEWEB)

Dillert, Ralf, E-mail: dillert@iftc.uni-hannover.de [Institut fuer Technische Chemie, Leibniz Universitaet Hannover, Callinstr. 3, 30167 Hannover (Germany); Laboratorium fuer Nano- und Quantenengineering, Leibniz Universitaet Hannover, Schneiderberg 39, 30167 Hannover (Germany); Stoetzner, Julia [Institut fuer Technische Chemie, Leibniz Universitaet Hannover, Callinstr. 3, 30167 Hannover (Germany); Engel, Astrid [Institut fuer Technische Chemie, Leibniz Universitaet Hannover, Callinstr. 3, 30167 Hannover (Germany); Laboratorium fuer Nano- und Quantenengineering, Leibniz Universitaet Hannover, Schneiderberg 39, 30167 Hannover (Germany); Bahnemann, Detlef W. [Institut fuer Technische Chemie, Leibniz Universitaet Hannover, Callinstr. 3, 30167 Hannover (Germany)

2012-04-15

Highlights: Black-Right-Pointing-Pointer The photocatalytic oxidation of nitrogen(II) oxide at the TiO{sub 2} surface was studied. Black-Right-Pointing-Pointer The effect of the UV(A) light intensity on the reaction rate was evaluated. Black-Right-Pointing-Pointer The effect of the NO concentration on the reaction rate was evaluated. Black-Right-Pointing-Pointer A mechanistic model for the heterogeneous NO oxidation is presented. Black-Right-Pointing-Pointer A rate law describing the influence of NO concentration and light intensity is given. - Abstract: Air pollution by nitrogen oxides represents a serious environmental problem in urban areas where numerous sources of these pollutants are concentrated. One approach to reduce the concentration of these air pollutants is the light-induced oxidation in the presence of molecular oxygen and a photocatalytically active building material, e.g., paints, roof tiles, or pavement stones. Herein, results of an investigation concerning the photocatalytic oxidation of nitrogen(II) oxide (NO) in the presence of molecular oxygen and UV(A) irradiated TiO{sub 2} powder are presented. The standard operating procedure described in ISO 22197-1 which was developed to characterize the photocatalytic activity of air-cleaning products was successfully applied to determine the photocatalytic activity of a bare TiO{sub 2} powder. The experimental data reveal that at the light intensity stipulated by the operation procedure the amount of NO removed from the gas phase by photocatalytic oxidation is strongly affected by small changes of this light intensity as well as of the NO concentration in the gas stream in the photoreactor. Therefore, these parameters have to be controlled very carefully. Based upon the experimental data obtained in this study a rate law for the photocatalytic NO oxidation inside the photoreactor is derived.

Odd nitrogen production by meteoroids

Science.gov (United States)

Park, C.; Menees, G. P.

1978-01-01

The process by which odd nitrogen species (atomic nitrogen and nitric oxide) are formed during atmospheric entry of meteoroids is analyzed theoretically. An ablating meteoroid is assumed to be a point source of mass with a continuum regime evolving in its wake. The amounts of odd nitrogen species, produced by high-temperature reactions of air in the continuum wake, are calculated by numerical integration of chemical rate equations. Flow properties are assumed to be uniform across the wake, and 29 reactions involving five neutral species and five singly ionized species are considered, as well as vibrational and electron temperature nonequilibrium phenomena. The results, when they are summed over the observed mass, velocity, and entry-angle distribution of meteoroids, provide odd-nitrogen-species annual global production rates as functions of altitude. The peak production of nitric oxide is found to occur at an altitude of about 85 km; atomic nitrogen production peaks at about 95 km. The total annual rate for nitric oxide is 40 million kg; for atomic nitrogen it is 170 million kg.

Direct deposition of aluminum oxide gate dielectric on graphene channel using nitrogen plasma treatment

International Nuclear Information System (INIS)

Lim, Taekyung; Kim, Dongchool; Ju, Sanghyun

2013-01-01

Deposition of high-quality dielectric on a graphene channel is an essential technology to overcome structural constraints for the development of nano-electronic devices. In this study, we investigated a method for directly depositing aluminum oxide (Al 2 O 3 ) on a graphene channel through nitrogen plasma treatment. The deposited Al 2 O 3 thin film on graphene demonstrated excellent dielectric properties with negligible charge trapping and de-trapping in the gate insulator. A top-gate-structural graphene transistor was fabricated using Al 2 O 3 as the gate dielectric with nitrogen plasma treatment on graphene channel region, and exhibited p-type transistor characteristics

Staged combustion - main method for suppressing nitrogen oxides in pulverized-coal fired boilers

Energy Technology Data Exchange (ETDEWEB)

Kotler, V.R. (Vsesoyuznyi Teplotekhnicheskii Institut (USSR))

1989-08-01

Describes principles behind staged combustion, which is based on organizing furnace operations so that only part of the air from the fuel is taken into the furnace. The remaining air, which is needed for combustion, is fed as a tertiary blast jet into the intermediate flame zone. Following inflammation and combustion of the volatile matter, the oxygen concentration in the flame drops sharply causing a retardation of the oxidation reactions forming NO and an intensification of the reactions causing the nitrogen-containing radicals NH{sub i} and CN to be converted into N{sub 2}. When the reducing agents CO, H{sub 2} and CH{sub 4} are present in certain flame zones, even the nitrogen oxide is reduced to N{sub 2}. The NO concentrations in the flame are reduced until the jet of tertiary air is introduced. Discusses with reference to practice in the USA and Western Europe how to achieve maximum effect of this method for different types of boiler and presents the results of observations of the introduction of staged combustion to the BKZ-210-140 boiler burning Kuznetsk gassy coal. 5 refs.

Three-dimensional Nitrogen-Doped Reduced Graphene Oxide/Carbon Nanotube Composite Catalysts for Vanadium Flow Batteries

Energy Technology Data Exchange (ETDEWEB)

Fu, Shaofang [School of Mechanical and Materials Engineering, Washington State University, WA, 99164 USA.; Zhu, Chengzhou [School of Mechanical and Materials Engineering, Washington State University, WA, 99164 USA.; Song, Junhua [School of Mechanical and Materials Engineering, Washington State University, WA, 99164 USA.; Engelhard, Mark H. [Environmental Molecular Science Laboratory, Pacific Northwest National Laboratory, Richland, WA 99354 USA.; Du, Dan [School of Mechanical and Materials Engineering, Washington State University, WA, 99164 USA.; Lin, Yuehe [School of Mechanical and Materials Engineering, Washington State University, WA, 99164 USA.; Environmental Molecular Science Laboratory, Pacific Northwest National Laboratory, Richland, WA 99354 USA.

2017-02-22

The development of vanadium redox flow battery is limited by the sluggish kinetics of the reaction, especially the cathodic VO2+/VO2+ redox couples. Therefore, it is vital to develop new electrocatalyst with enhanced activity to improve the battery performance. Herein, we first synthesized the hydrogel precursor by a facile hydrothermal method. After the following carbonization, nitrogen-doped reduced graphene oxide/carbon nanotube composite was obtained. By virtue of the large surface area and good conductivey, which are ensured by the unique hybrid structure, as well as the proper nitrogen doping, the as-prepared composite presents enhanced catalytic performance toward the VO2+/VO2+ redox reaction. We also demonstrated the composite with carbon nanotube loading of 2 mg/mL exhibits the highest activity and remarkable stability in aqueous solution due to the strong synergy between reduced graphene oxide and carbon nanotubes, indicating that this composite might show promising applications in vanadium redox flow battery.

Lanthanide ions (III) as sensitizers of melatonin oxidation in reaction mixtures providing reactive species of oxygen and nitrogen

Energy Technology Data Exchange (ETDEWEB)

Kaczmarek, Małgorzata, E-mail: mkaczmar@amu.edu.pl

2015-06-15

Chemiluminescence (CL) of the reactive systems providing strong oxidants (reactive species of oxygen and nitrogen) containing lanthanide ions (III) and melatonin, was studied. Kinetic curves of emission decay and spectral distributions of chemiluminescence were obtained. Analysis of differences in the intensity of chemiluminescence and CL spectra proved that excitation of Tb(III) and Dy(III) ions takes place with the energy transfer from the products of melatonin oxidation: N{sup 1}-acetyl-N{sup 2}-formyl-5-methoxykynuramine (AFMK) and N{sup 1}-acetyl-5-methoxykynuramine (AMK) to the lanthanide ions. In the system Fe(II)/Fe(III)–H{sub 2}O{sub 2}–Mel–Tb(III) a linear correlation was established between the integrated CL intensity and melatonin concent. - Highlights: • Chemiluminescence (CL) of melatonin (Mel) oxidation by reactive species of oxygen and nitrogen. • Tb(III) and Dy(III) ions as sensitizers of a melatonin oxidation process. • New CL method for determination of melatonin in pharmaceutical preparations based on CL of Fe(II)/Fe(III)–H{sub 2}O{sub 2}–Mel–Tb(III) system.

Wisconsin Inventors' Network Database final report

Energy Technology Data Exchange (ETDEWEB)

1991-12-04

The Wisconsin Innovation Service Center at UW-Whitewater received a DOE grant to create an Inventor's Network Database to assist independent inventors and entrepreneurs with new product development. Since 1980, the Wisconsin Innovation Service Center (WISC) at the University of Wisconsin-Whitewater has assisted independent and small business inventors in estimating the marketability of their new product ideas and inventions. The purpose of the WISC as an economic development entity is to encourage inventors who appear to have commercially viable inventions, based on preliminary market research, to invest in the next stages of development, perhaps investigating prototype development, legal protection, or more in-depth market research. To address inventor's information needs, WISC developed on electronic database with search capabilities by geographic region and by product category/industry. It targets both public and private resources capable of, and interested in, working with individual and small business inventors. At present, the project includes resources in Wisconsin only.

Removal of nitrogen oxides, 106RuO4 vapors and radioactive aerosols from the gas originating in radioactive wastes solidification

International Nuclear Information System (INIS)

Kepak, F.; Pecak, V.; Uher, E.; Kanka, J.; Koutova, S.; Matous, V.

1985-01-01

Procedures and equipment for the disposal of nitrogen oxides, RuO 4 vapors and radioactive aerosols of 90 Sr, 137 Cs, 60 Co and 125 Sb contained in the gas generated in the solidification of high- and intermediate-level radioactive wastes were tested on models. Nitrogen oxides were disposed of by absorption and chemical decomposition in various solutions of which the best results gave solutions of ammonium salts. Absorption in solutions, physical and chemical sorption on inorganic sorbents were tested for the disposal of RuO 4 . Aerosols were disposed of by absorption in absorption media with subsequent filtration. Of fibrous filter materials, Czechoslovak AEROS-2 and RA-2 filter papers were proven in the tests. Attention was also devoted to granular filter materials of which silica gel was chosen. On the basis of laboratory tests a multi-step treatment system was designed which consists of a condenser, a nitrogen oxide absorber, a liquid aerosol separator, absorption columns and aerosol filters. The whole system has been manufactured on pilot plant scale and the different parts are being produced. (Z.M.)

Alternative Fuels Data Center: Wisconsin Reduces Emissions With Natural Gas

Science.gov (United States)

Trucks Wisconsin Reduces Emissions With Natural Gas Trucks to someone by E-mail Share Alternative Fuels Data Center: Wisconsin Reduces Emissions With Natural Gas Trucks on Facebook Tweet about Alternative Fuels Data Center: Wisconsin Reduces Emissions With Natural Gas Trucks on Twitter Bookmark

Real-time measurements of nitrogen oxide emissions from in-use New York City transit buses using a chase vehicle.

Science.gov (United States)

Shorter, Joanne H; Herndon, Scott; Zahniser, Mark S; Nelson, David D; Wormhoudt, Joda; Demerjian, Kenneth L; Kolb, Charles E

2005-10-15

New diesel engine technologies and alternative fuel engines are being introduced into fleets of mass transit buses to try to meet stricter emission regulations of nitrogen oxides and particulates: Real-time instruments including an Aerodyne Research tunable infrared laser differential absorption spectrometer (TILDAS) were deployed in a mobile laboratory to assess the impact of the implementation of the new technologies on nitrogen oxide emissions in real world driving conditions. Using a "chase" vehicle sampling strategy, the mobile laboratory followed target vehicles, repeatedly sampling their exhaust. Nitrogen oxides from approximately 170 in-use New York City mass transit buses were sampled during the field campaigns. Emissions from conventional diesel buses, diesel buses with continuously regenerating technology (CRT), diesel hybrid electric buses, and compressed natural gas (CNG) buses were compared. The chase vehicle sampling method yields real world emissions that can be included in more realistic emission inventories. The NO, emissions from the diesel and CNG buses were comparable. The hybrid electric buses had approximately one-half the NOx emissions. In CRT diesels, NO2 accounts for about one-third of the NOx emitted in the exhaust, while for non-CRT buses the NO2 fraction is less than 10%.

Nitrous oxide flux from landfill leachate-sawdust nitrogenous compost

International Nuclear Information System (INIS)

Hui, C.H.; So, M.K.; Lee, C.M.; Chan, G.Y.S.

2003-01-01

Composted nitrogenous waste has the potential to produce excessive amounts of nitrous oxide (N 2 O), a potent greenhouse gas that also contributes to stratospheric ozone depletion. In this laboratory study, sawdust was irrigated with varying amounts of landfill leachate with high NH 4 + -N content (3950 mg l -1 ). Physicochemical properties, including the amount of N 2 O produced, were monitored during the composting process over 28 days. A rapid decline in NH 4 + -N in the first 4 days and increasing NO 3 - -N for 11 days was followed by lower but stabilized levels of available-N, even with repeated leachate irrigation. Less than 0.03% of the leachate-applied N was lost as N 2 O. Higher leachate applications as much as tripled N 2 O production, but this represented a lesser proportion overall of the total nitrogen. Addition of glucose to the composting process had no significant effect on N 2 O production. The derived sawdust-leachate compost supported healthy growth of Sesbania rostrata. It is concluded that compost can be produced from sawdust irrigated with landfill leachate without substantial emission of N 2 O, although excessive flux of N 2 O remains about high application rates over longer time periods. (Author)

Implementing high-speed rail in Wisconsin peer exchange.

Science.gov (United States)

2009-01-01

The Wisconsin Department of Transportation Division of Transportation Investment Management hosted : a peer exchange on June 2 -4, 2009 in Milwaukee, Wisconsin. Representatives from four state DOTs and : two freight railroads joined representatives f...

Marine nitrogen cycle

Digital Repository Service at National Institute of Oceanography (India)

Naqvi, S.W.A.

) such as the Marine nitrogen cycle The marine nitrogen cycle. ‘X’ and ‘Y’ are intra-cellular intermediates that do not accumulate in water column. (Source: Codispoti et al., 2001) Page 1 of 3Marine nitrogen cycle - Encyclopedia of Earth 11/20/2006http://www... and nitrous oxide budgets: Moving targets as we enter the anthropocene?, Sci. Mar., 65, 85-105, 2001. Page 2 of 3Marine nitrogen cycle - Encyclopedia of Earth 11/20/2006http://www.eoearth.org/article/Marine_nitrogen_cycle square6 Gruber, N.: The dynamics...

The Lightning Nitrogen Oxides Model (LNOM): Status and Recent Applications

Science.gov (United States)

Koshak, William; Khan, Maudood; Peterson, Harold

2011-01-01

Improvements to the NASA Marshall Space Flight Center Lightning Nitrogen Oxides Model (LNOM) are discussed. Recent results from an August 2006 run of the Community Multiscale Air Quality (CMAQ) modeling system that employs LNOM lightning NOx (= NO + NO2) estimates are provided. The LNOM analyzes Lightning Mapping Array (LMA) data to estimate the raw (i.e., unmixed and otherwise environmentally unmodified) vertical profile of lightning NOx. The latest LNOM estimates of (a) lightning channel length distributions, (b) lightning 1-m segment altitude distributions, and (c) the vertical profile of NOx are presented. The impact of including LNOM-estimates of lightning NOx on CMAQ output is discussed.

Process for the reduction of nitrogen oxides in an effluent

Energy Technology Data Exchange (ETDEWEB)

Epperly, W.R.; Sullivan, J.C.; Sprague, B.N.

1989-07-04

This patent describes a process for the reduction of the concentration of nitrogen oxides in the effluent from the combustion of a carbonaceous fuel. The process comprises introducing a treatment agent which comprises a composition selected from the group consisting of NH/sub 4/-lignosulfonate, calcium lignosulfonate, 2-furoic acid, 1,3 dioxolane, tetrahydrofuran, furfurylamine, furfurylalcohol, gluconic acid, citric acid, n-butyl acetate, 1,3 butylene glycol, methylal, tetrahydrofuryl alcohol, furan, fish oil, coumalic acid, furfuryl acetate, tetrahydrofuran 2,3,4,5-tetracarboxylic acid, tetrahydrofurylamine, furylacrylic acid, tetrahydropyran, 2,5-furandimethanol, mannitol, hexamethylenediamine, barbituric acid, acetic anhydride, oxalic acid, mucic acid and d-galactose.

Survival of adult martens in Northern Wisconsin

Science.gov (United States)

Nicholas P. McCann; Patrick A. Zollner; Jonathan H. Gilbert

2010-01-01

Low adult marten (Martes americana) survival may be one factor limiting their population growth >30 yr after their reintroduction in Wisconsin, USA. We estimated annual adult marten survival at 0.81 in northern Wisconsin, with lower survival during winter (0.87) than summer-fall (1.00). Fisher (Martes pennanti) and raptor kills...

System and method for controlling ammonia levels in a selective catalytic reduction catalyst using a nitrogen oxide sensor

Science.gov (United States)

None

2017-07-25

A system according to the principles of the present disclosure includes an air/fuel ratio determination module and an emission level determination module. The air/fuel ratio determination module determines an air/fuel ratio based on input from an air/fuel ratio sensor positioned downstream from a three-way catalyst that is positioned upstream from a selective catalytic reduction (SCR) catalyst. The emission level determination module selects one of a predetermined value and an input based on the air/fuel ratio. The input is received from a nitrogen oxide sensor positioned downstream from the three-way catalyst. The emission level determination module determines an ammonia level based on the one of the predetermined value and the input received from the nitrogen oxide sensor.

Dissimilatory Metabolism of Nitrogen Oxides in Bacteria:Comparative Reconstruction of Transcriptional Networks

Energy Technology Data Exchange (ETDEWEB)

Rodionov, Dmitry A.; Dubchak, Inna L.; Arkin, Adam P.; Alm, EricJ.; Gelfand, Mikhail S.

2005-09-01

Bacterial response to nitric oxide (NO) is of major importance since NO is an obligatory intermediate of the nitrogen cycle. Transcriptional regulation of the dissimilatory nitric oxides metabolism in bacteria is diverse and involves FNR-like transcription factors HcpR, DNR and NnrR, two-component systems NarXL and NarQP, NO-responsive activator NorR, and nitrite sensitive repressor NsrR. Using comparative genomics approaches we predict DNA-binding signals for these transcriptional factors and describe corresponding regulons in available bacterial genomes. Within the FNR family of regulators, we observed a correlation of two specificity-determining amino acids and contacting bases in corresponding DNA signal. Highly conserved regulon HcpR for the hybrid cluster protein and some other redox enzymes is present in diverse anaerobic bacteria including Clostridia, Thermotogales and delta-proteobacteria. NnrR and DNR control denitrification in alpha- and beta-proteobacteria, respectively. Sigma-54-dependent NorR regulon found in some gamma- and beta-proteobacteria contains various enzymes involved in the NO detoxification. Repressor NsrR, which was previously known to control only nitrite reductase operon in Nitrosomonas spp., appears to be the master regulator of the nitric oxides metabolism not only in most gamma- and beta-proteobacteria (including well-studied species like Escherichia coli), but also in Gram-positive Bacillus and Streptomyces species. Positional analysis and comparison of regulatory regions of NO detoxification genes allows us to propose the candidate NsrR-binding signal. The most conserved member of the predicted NsrR regulon is the NO-detoxifying flavohemoglobin Hmp. In enterobacteria, the regulon includes also two nitrite-responsive loci, nipAB (hcp-hcr) and nipC(dnrN), thus confirming the identity of the effector, i.e., nitrite. The proposed NsrR regulons in Neisseria and some other species are extended to include denitrification genes. As the

Dissimilatory metabolism of nitrogen oxides in bacteria: comparative reconstruction of transcriptional networks.

Directory of Open Access Journals (Sweden)

2005-10-01

Full Text Available Bacterial response to nitric oxide (NO is of major importance since NO is an obligatory intermediate of the nitrogen cycle. Transcriptional regulation of the dissimilatory nitric oxides metabolism in bacteria is diverse and involves FNR-like transcription factors HcpR, DNR, and NnrR; two-component systems NarXL and NarQP; NO-responsive activator NorR; and nitrite-sensitive repressor NsrR. Using comparative genomics approaches, we predict DNA-binding motifs for these transcriptional factors and describe corresponding regulons in available bacterial genomes. Within the FNR family of regulators, we observed a correlation of two specificity-determining amino acids and contacting bases in corresponding DNA recognition motif. Highly conserved regulon HcpR for the hybrid cluster protein and some other redox enzymes is present in diverse anaerobic bacteria, including Clostridia, Thermotogales, and delta-proteobacteria. NnrR and DNR control denitrification in alpha- and beta-proteobacteria, respectively. Sigma-54-dependent NorR regulon found in some gamma- and beta-proteobacteria contains various enzymes involved in the NO detoxification. Repressor NsrR, which was previously known to control only nitrite reductase operon in Nitrosomonas spp., appears to be the master regulator of the nitric oxides' metabolism, not only in most gamma- and beta-proteobacteria (including well-studied species such as Escherichia coli, but also in Gram-positive Bacillus and Streptomyces species. Positional analysis and comparison of regulatory regions of NO detoxification genes allows us to propose the candidate NsrR-binding motif. The most conserved member of the predicted NsrR regulon is the NO-detoxifying flavohemoglobin Hmp. In enterobacteria, the regulon also includes two nitrite-responsive loci, nipAB (hcp-hcr and nipC (dnrN, thus confirming the identity of the effector, i.e. nitrite. The proposed NsrR regulons in Neisseria and some other species are extended to include

Solid State Electrochemical Sensors for Nitrogen Oxide (NOx) Detection in Lean Exhaust Gases

OpenAIRE

Rheaume, Jonathan Michael

2010-01-01

Solid state electrochemical sensors that measure nitrogen oxides (NOx) in lean exhaust have been investigated in order to help meet future on-board diagnostic (OBD) regulations for diesel vehicles. This impedancemetric detection technology consists of a planar, single cell sensor design with various sensing electrode materials and yttria-stabilized zirconia (YSZ) as the electrolyte. No reference to ambient air is required. An impedance analysis method yields a signal that is proportional to t...

Ammonia oxidizer populations vary with nitrogen cycling across a tropical montane mean annual temperature gradient

Science.gov (United States)

S. Pierre; I. Hewson; J. P. Sparks; C. M. Litton; C. Giardina; P. M. Groffman; T. J. Fahey

2017-01-01

Functional gene approaches have been used to better understand the roles of microbes in driving forest soil nitrogen (N) cycling rates and bioavailability. Ammonia oxidation is a rate limiting step in nitrification, and is a key area for understanding environmental constraints on N availability in forests. We studied how increasing temperature affects the role of...

Catalytic pleat filter bags for combined particulate separation and nitrogen oxides removal from flue gas streams

International Nuclear Information System (INIS)

Park, Young Ok; Choi, Ho Kyung

2010-01-01

The development of a high temperature catalytically active pleated filter bag with hybrid filter equipment for the combined removal of particles and nitrogen oxides from flue gas streams is presented. A special catalyst load in stainless steel mesh cartridge with a high temperature pleated filter bag followed by optimized catalytic activation was developed to reach the required nitrogen oxides levels and to maintain the higher collection efficiencies. The catalytic properties of the developed high temperature filter bags with hybrid filter equipment were studied and demonstrated in a pilot scale test rig and a demonstration plant using commercial scale of high temperature catalytic pleated filter bags. The performance of the catalytic pleated filter bags were tested under different operating conditions, such as filtration velocity and operating temperature. Moreover, the cleaning efficiency and residual pressure drop of the catalyst loaded cartridges in pleated filter bags were tested. As result of theses studies, the optimum operating conditions for the catalytic pleated filter bags are determined. (author)

Improved creep and oxidation behavior of a martensitic 9Cr steel by the controlled addition of boron and nitrogen

Energy Technology Data Exchange (ETDEWEB)

Mayr, Peter [Massachusetts Institute of Technology, Cambridge, MA (United States). Dept. of Materials Science; Graz Univ. of Technology (Austria). Inst. of Material Science and Welding; Holzer, Ivan; Mendez-Martin, Francisca [Graz Univ. of Technology (Austria). Inst. of Material Science and Welding; Albu, Mihaela; Mitsche, Stefan [Graz Univ. of Technology (Austria). Inst. for Electron Microscopy; Gonzalez, Vanessa; Agueero, Alina [Instituto Nacional de Tecnica Aeroespacial, Torrejon de Ardoz (Spain)

2010-07-01

This manuscript gives an overview on recent developments of a martensitic steel grade based on 9Cr3W3CoVNb with controlled additions of boron and nitrogen. Alloy design by thermodynamic equilibrium calculations and calculation of boron-nitrogen solubility is discussed. Out of this alloy design process, two melts of a 9Cr3W3CoVNbBN steel were produced. The investigation focused on microstructural evolution during high temperature exposure, creep properties and oxidation resistance in steam at 650 C. Microstructural characterization of ''as-received'' and creep exposed material was carried out using conventional optical as well as advanced electron microscopic methods. Creep data at 650 was obtained at various stress levels. Longest-running specimens have reached more than 20,000 hours of testing time. In parallel, long-term oxidation resistance has been studied at 650 C in steam atmosphere up to 5,000 hours. Preliminary results of the extensive testing program on a 9Cr3W3CoVNbBN steel show significant improvement in respect to creep strength and oxidation resistance compared to the state-of-the-art 9 wt. % Cr martensitic steel grades. Up to current testing times, the creep strength is significantly beyond the +20% scatterband of standard grade P92 material. Despite the chromium content of 9 wt % the material exhibits excellent oxidation resistance. Steam exposed plain base material shows comparable oxidation behavior to coated material, and the corrosion rate of the boron-nitrogen controlled steel is much lower compared to standard 9 wt % Cr steel grades, P91 and P92. (orig.)

Selective catalytic oxidation of ammonia

Energy Technology Data Exchange (ETDEWEB)

Leppaelahti, J; Koljonen, T [VTT Energy, Espoo (Finland)

1997-12-31

In the combustion of fossil fuels, the principal source of nitrogen oxides is nitrogen bound in the fuel structure. In gasification, a large part of fuel nitrogen forms NH{sub 3}, which may form nitrogen oxides during gas combustion. If NH{sub 3} and other nitrogen species could be removed from hot gas, the NO emission could be considerably reduced. However, relatively little attention has been paid to finding new means of removing nitrogen compounds from the hot gasification gas. The possibility of selectively oxidizing NH{sub 3} to N{sub 2} in the hot gasification has been studied at VTT Energy. The largest NH{sub 3} reductions have been achieved by catalytic oxidation on aluminium oxides. (author) (4 refs.)

Selective catalytic oxidation of ammonia

Energy Technology Data Exchange (ETDEWEB)

Leppaelahti, J.; Koljonen, T. [VTT Energy, Espoo (Finland)

1996-12-31

In the combustion of fossil fuels, the principal source of nitrogen oxides is nitrogen bound in the fuel structure. In gasification, a large part of fuel nitrogen forms NH{sub 3}, which may form nitrogen oxides during gas combustion. If NH{sub 3} and other nitrogen species could be removed from hot gas, the NO emission could be considerably reduced. However, relatively little attention has been paid to finding new means of removing nitrogen compounds from the hot gasification gas. The possibility of selectively oxidizing NH{sub 3} to N{sub 2} in the hot gasification has been studied at VTT Energy. The largest NH{sub 3} reductions have been achieved by catalytic oxidation on aluminium oxides. (author) (4 refs.)

Influence of nitrogen on magnetic properties of indium oxide

Science.gov (United States)

Ashok, Vishal Dev; De, S. K.

2013-07-01

Magnetic properties of indium oxide (In2O3) prepared by the decomposition of indium nitrate/indium hydroxide in the presence of ammonium chloride (NH4Cl) has been investigated. Structural and optical characterizations confirm that nitrogen is incorporated into In2O3. Magnetization has been convoluted to individual diamagnetic paramagnetic and ferromagnetic contributions with varying concentration of NH4Cl. Spin wave with diverging thermal exponent dominates in both field cool and zero field cool magnetizations. Uniaxial anisotropy plays an important role in magnetization as a function of magnetic field at higher concentration of NH4Cl. Avrami analysis indicates the absence of pinning effect in the magnetization process. Ferromagnetism has been interpreted in terms of local moments induced by anion dopant and strong hybridization with host cation.

Influence of nitrogen on magnetic properties of indium oxide

International Nuclear Information System (INIS)

Ashok, Vishal Dev; De, S K

2013-01-01

Magnetic properties of indium oxide (In 2 O 3 ) prepared by the decomposition of indium nitrate/indium hydroxide in the presence of ammonium chloride (NH 4 Cl) has been investigated. Structural and optical characterizations confirm that nitrogen is incorporated into In 2 O 3 . Magnetization has been convoluted to individual diamagnetic paramagnetic and ferromagnetic contributions with varying concentration of NH 4 Cl. Spin wave with diverging thermal exponent dominates in both field cool and zero field cool magnetizations. Uniaxial anisotropy plays an important role in magnetization as a function of magnetic field at higher concentration of NH 4 Cl. Avrami analysis indicates the absence of pinning effect in the magnetization process. Ferromagnetism has been interpreted in terms of local moments induced by anion dopant and strong hybridization with host cation. (paper)

Heterogeneous oxidation of SO2 in the radiation chemical purification of exhaust gases of thermoelectric power plants from oxides of nitrogen and sulfur

International Nuclear Information System (INIS)

Gerasimova, T.S.; Gerasimov, G.Ya.; Tokmacheva, I.P.

1992-01-01

Questions associated with numerical modeling of the heterogeneous oxidation of SO 2 in exhaust gases of thermoelectric power plants, induced by irradiation of the gas with a flux of fast electrons, are discussed. In constructing a mathematical model of the process it is considered that a phase equilibrium exists between the gas and the aerosol drops formed in the gas under the radiation influence, and the rate of the process is determined by the rate of liquid-phase oxidation of SO 2 by nitrogen dioxide in dissolved form. 7 refs., 4 figs

Nitrogen grain-boundary passivation of In-doped ZnO transparent conducting oxide

Science.gov (United States)

Ali, D.; Butt, M. Z.; Coughlan, C.; Caffrey, D.; Shvets, I. V.; Fleischer, K.

2018-04-01

We have investigated the properties and conduction limitations of spray pyrolysis grown, low-cost transparent conducting oxide ZnO thin films doped with indium. We analyze the optical, electrical, and crystallographic properties as functions of In content with a specific focus on postgrowth heat treatment of these thin films at 320 ∘C in an inert, nitrogen atmosphere, which improves the films electrical properties considerably. The effect was found to be dominated by nitrogen-induced grain-boundary passivation, identified by a combined study using i n situ resistance measurement upon annealing, x-ray photoelectron spectroscopy, photoluminescence, and x-ray diffraction studies. We also highlight the chemical mechanism of morphologic and crystallographic changes found in films with high indium content. By optimizing growth conditions according to these findings, ZnO:In with a resistivity as low as 2 ×10 -3Ω cm , high optical quality (T ≈90 % ), and sheet resistance of 32 Ω /□ has been obtained without any need for postgrowth treatments.

Nitrous oxide emissions from a golf course fairway and rough following application of different nitrogen fertilizers

Science.gov (United States)

Nitrous oxide (N2O) is a potent greenhouse gas that destroys stratospheric ozone. There is limited research of golf course N2O emission and the effects of frequent fertilization and irrigation. Three enhanced efficiency nitrogen fertilizers (EENFs) were applied to a Colorado golf course fairway and ...

Experimental study of reduce of nitrogen oxides emission in the Environment at the Ekibastuz coal combustion

International Nuclear Information System (INIS)

Korabejnikova, V.K.

2004-01-01

For revealing conditions decrease in emissions of nitrogen oxide in an environment at three-stage burning of coal dust Ekibastuz coal with use two-line burners (on were the experimental research of test on fiery the stand as a result of which acknowledgement of theoretical results is received. (author)

Analysis of Chemical Reaction Kinetics Behavior of Nitrogen Oxide During Air-staged Combustion in Pulverized Boiler

Directory of Open Access Journals (Sweden)

Jun-Xia Zhang

2016-03-01

Full Text Available Because the air-staged combustion technology is one of the key technologies with low investment running costs and high emission reduction efficiency for the pulverized boiler, it is important to reveal the chemical reaction kinetics mechanism for developing various technologies of nitrogen oxide reduction emissions. At the present work, a three-dimensional mesh model of the large-scale four corner tangentially fired boiler furnace is established with the GAMBIT pre-processing of the FLUENT software. The partial turbulent premixed and diffusion flame was simulated for the air-staged combustion processing. Parameters distributions for the air-staged and no the air-staged were obtained, including in-furnace flow field, temperature field and nitrogen oxide concentration field. The results show that the air-staged has more regular velocity field, higher velocity of flue gas, higher turbulence intensity and more uniform temperature of flue gas. In addition, a lower negative pressure zone and lower O2 concentration zone is formed in the main combustion zone, which is conducive to the NO of fuel type reduced to N2, enhanced the effect of NOx reduction. Copyright © 2016 BCREC GROUP. All rights reserved Received: 5th November 2015; Revised: 14th January 2016; Accepted: 16th January 2016  How to Cite: Zhang, J.X., Zhang, J.F. (2016. Analysis of Chemical Reaction Kinetics Behavior of Nitrogen Oxide During Air-staged Combustion in Pulverized Boiler. Bulletin of Chemical Reaction Engineering & Catalysis, 11 (1: 100-108. (doi:10.9767/bcrec.11.1.431.100-108 Permalink/DOI: http://dx.doi.org/10.9767/bcrec.11.1.431.100-108

Modeling Electron Competition among Nitrogen Oxides Reduction and N₂O Accumulation in Hydrogenotrophic Denitrification

DEFF Research Database (Denmark)

Liu, Yiwen; Ngo, Huu Hao; Guo, Wenshan

2018-01-01

Hydrogenotrophic denitrification is a novel and sustainable process for nitrogen removal, which utilizes hydrogen as electron donor and carbon dioxide as carbon source. Recent studies have shown that nitrous oxide (N2O), a highly undesirable intermediate and potent greenhouse gas, can accumulate...

Geographic and racial variation in teen pregnancy rates in Wisconsin.

Science.gov (United States)

Layde, Molly M; Remington, Patrick L

2013-08-01

Despite recent declines in teen birth rates, teenage pregnancy remains an important public health problem in Wisconsin with significant social, economic, and health-related effects. Compare and contrast teen birth rate trends by race, ethnicity, and county in Wisconsin. Teen (ages 15-19 years) birth rates (per 1000 teenage females) in Wisconsin from 2001-2010 were compared by racelethnicity and county of residence using data from the Wisconsin Interactive Statistics on Health. Teen birth rates in Wisconsin have declined by 20% over the past decade, from 35.5/1000 teens in 2001 to 28.3/1000 teens in 2010-a relative decline of 20.3%. However, trends vary by race, with declines among blacks (-33%) and whites (-26%) and increases among American Indians (+21%) and Hispanics (+30%). Minority teen birth rates continue to be 3 to 5 times greater than birth rates among whites. Rates varied even more by county, with an over 14-fold difference between Ozaukee County (7.8/1000) and Menominee County (114.2). Despite recent declines, teen pregnancy continues to be an important public health problem in Wisconsin. Pregnancy prevention programs should be targeted toward the populations and counties with the highest rates.

Bioinspired aerobic oxidation of secondary amines and nitrogen heterocycles with a bifunctional quinone catalyst.

Science.gov (United States)

Wendlandt, Alison E; Stahl, Shannon S

2014-01-08

Copper amine oxidases are a family of enzymes with quinone cofactors that oxidize primary amines to aldehydes. The native mechanism proceeds via an iminoquinone intermediate that promotes high selectivity for reactions with primary amines, thereby constraining the scope of potential biomimetic synthetic applications. Here we report a novel bioinspired quinone catalyst system consisting of 1,10-phenanthroline-5,6-dione/ZnI2 that bypasses these constraints via an abiological pathway involving a hemiaminal intermediate. Efficient aerobic dehydrogenation of non-native secondary amine substrates, including pharmaceutically relevant nitrogen heterocycles, is demonstrated. The ZnI2 cocatalyst activates the quinone toward amine oxidation and provides a source of iodide, which plays an important redox-mediator role to promote aerobic catalytic turnover. These findings provide a valuable foundation for broader development of aerobic oxidation reactions employing quinone-based catalysts.

Nurses for Wisconsin: A Collaborative Initiative to Enhance the Nurse Educator Workforce.

Science.gov (United States)

Young, Linda K; Adams, Jan L; Lundeen, Sally; May, Katharyn A; Smith, Rosemary; Wendt, L Elaine

2016-01-01

Wisconsin, like much of the nation, is currently suffering from a growing nursing shortage. The University of Wisconsin-Eau Claire College of Nursing and Health Sciences, in partnership with the University of Wisconsin-Madison, University of Wisconsin-Milwaukee, and University of Wisconsin Oshkosh nursing programs, took advantage of a University of Wisconsin System Incentive Grant for economic and workforce development to address this problem. With a $3.2 million award, the Nurses for Wisconsin goal is to increase the number of baccalaureate registered nurses by expanding the nursing education capacity within the University of Wisconsin System. Nurses for Wisconsin is accelerating the preparation of nursing faculty by supporting nurses to enroll in doctor of nursing practice or nursing doctor of philosophy programs with pre- and postdoctoral fellowship awards ranging from $21,500 to $90,000 and the recruitment of faculty with a loan repayment program of up to $50,000. In exchange for the financial support, fellows and faculty must make a 3-year commitment to teach in a UW System nursing program. Two conferences for program participants are also funded through the award. The first conference was held in October 2014. The second conference is scheduled for summer 2015. With the first year of the 2-year project completed, this article describes Nurses for Wisconsin from inception to implementation and midterm assessment with a focus on lessons learned. A follow-up article addressing final outcomes and next steps is planned. Copyright © 2016 Elsevier Inc. All rights reserved.

Nitrogen trading tool

Science.gov (United States)

The nitrogen cycle is impacted by human activities, including those that increase the use of nitrogen in agricultural systems, and this impact can be seen in effects such as increased nitrate (NO3) levels in groundwater or surface water resources, increased concentration of nitrous oxide (N2O) in th...

Modeling Nitrous Oxide Production during Biological Nitrogen Removal via Nitrification and Denitrification: Extensions to the General ASM Models

DEFF Research Database (Denmark)

Ni, Bing-Jie; Ruscalleda, Maël; Pellicer i Nàcher, Carles

2011-01-01

on N2O production from four different mixed culture nitrification and denitrification reactor study reports. Modeling results confirm that hydroxylamine oxidation by ammonium oxidizers (AOB) occurs 10 times slower when NO2– participates as final electron acceptor compared to the oxic pathway. Among......Nitrous oxide (N2O) can be formed during biological nitrogen (N) removal processes. In this work, a mathematical model is developed that describes N2O production and consumption during activated sludge nitrification and denitrification. The well-known ASM process models are extended to capture N2O...

Thaumarchaeal ammonium oxidation and evidence for a nitrogen cycle in a subsurface radioactive thermal spring in the Austrian Central Alps

Directory of Open Access Journals (Sweden)

Friedrich Wolfgang Gerbl

2014-05-01

Full Text Available Previous studies had suggested the presence of ammonium oxidizing Thaumarchaeota as well as nitrite oxidizing Bacteria in the subsurface spring called Franz Josef Quelle (FJQ, a slightly radioactive thermal mineral spring with a temperature of 43.6 - 47oC near the alpine village of Bad Gastein, Austria. The microbiological consortium of the FJQ was investigated for its utilization of nitrogen compounds and the putative presence of a subsurface nitrogen cycle. Microcosm experiments made with samples from the spring water, containing planktonic microorganisms, or from biofilms, were used in this study. Three slightly different media, enriched with vitamins and trace elements, and two incubation temperatures (30 and 40oC, respectively were employed. Under aerobic conditions, high rates of conversion of ammonium to nitrite, as well as nitrite to nitrate were measured. Under oxygen-limited conditions nitrate was converted to gaseous compounds. Stable isotope probing with 15NH4Cl or (15NH42SO4 as sole energy sources revealed incorporation of 15N into community DNA. Genomic DNA as well as RNA were extracted from all microcosms. The following genes or fragments of genes were successfully amplified, cloned and sequenced by standard PCR from DNA extracts: Ammonia monooxygenase subunit A (amoA, nitrite oxidoreductase subunits A and B (nxrA and nxrB, nitrate reductase (narG, nitrite reductase (nirS, nitric oxide reductases (cnorB and qnorB, nitrous oxide reductase (nosZ. Reverse transcription of extracted total RNA and real-time PCR suggested the expression of each of those genes. Nitrogen fixation (as probed with nifH and nifD was not detected. However, a geological origin of NH4+ in the water of the FJQ cannot be excluded, considering the silicate, granite and gneiss containing environment. The data suggested the operation of a nitrogen cycle in the subsurface environment of the FJQ.

Thaumarchaeal ammonium oxidation and evidence for a nitrogen cycle in a subsurface radioactive thermal spring in the Austrian Central Alps.

Science.gov (United States)

Gerbl, Friedrich W; Weidler, Gerhard W; Wanek, Wolfgang; Erhardt, Angelika; Stan-Lotter, Helga

2014-01-01

Previous studies had suggested the presence of ammonium oxidizing Thaumarchaeota as well as nitrite oxidizing Bacteria in the subsurface spring called Franz Josef Quelle (FJQ), a slightly radioactive thermal mineral spring with a temperature of 43.6-47°C near the alpine village of Bad Gastein, Austria. The microbiological consortium of the FJQ was investigated for its utilization of nitrogen compounds and the putative presence of a subsurface nitrogen cycle. Microcosm experiments made with samples from the spring water, containing planktonic microorganisms, or from biofilms, were used in this study. Three slightly different media, enriched with vitamins and trace elements, and two incubation temperatures (30 and 40°C, respectively) were employed. Under aerobic conditions, high rates of conversion of ammonium to nitrite, as well as nitrite to nitrate were measured. Under oxygen-limited conditions nitrate was converted to gaseous compounds. Stable isotope probing with (15)NH4Cl or ((15)NH4)2SO4as sole energy sources revealed incorporation of (15)N into community DNA. Genomic DNA as well as RNA were extracted from all microcosms. The following genes or fragments of genes were successfully amplified, cloned and sequenced by standard PCR from DNA extracts: Ammonia monooxygenase subunit A (amoA), nitrite oxidoreductase subunits A and B (nxrA and nxrB), nitrate reductase (narG), nitrite reductase (nirS), nitric oxide reductases (cnorB and qnorB), nitrous oxide reductase (nosZ). Reverse transcription of extracted total RNA and real-time PCR suggested the expression of each of those genes. Nitrogen fixation (as probed with nifH and nifD) was not detected. However, a geological origin of NH(+) 4 in the water of the FJQ cannot be excluded, considering the silicate, granite and gneiss containing environment. The data suggested the operation of a nitrogen cycle in the subsurface environment of the FJQ.

Environmental Education in Wisconsin: What the Textbooks Teach.

Science.gov (United States)

Sanera, Michael

1996-01-01

This report contains a study done at the request of the Wisconsin Policy Research Institute, which studies public policy issues affecting the state of Wisconsin. Environmental education texts for Grades 6 through 10 were examined for scientific and economic accuracy, objectivity, and balance in accomplishing the following: 1) stating facts that…

Nitrogen-Doped Graphene:Effects of nitrogen species on the properties of the vanadium redox flow battery

International Nuclear Information System (INIS)

Shi, Lang; Liu, Suqin; He, Zhen; Shen, Junxi

2014-01-01

Nitrogen-doped graphene nanosheets (NGS), prepared by a simple hydrothermal reaction of graphene oxide (GO) with urea as nitrogen source were studied as positive electrodes in vanadium redox flow battery (VRFB). The synthesized NGS with the nitrogen level as high as 10.12 atom% is proven to be a promising material for VRFB. The structures and electrochemical properties of the materials are investigated by scanning electron microscopy, X-ray photoelectron spectroscopy, cyclic voltammetry and electrochemical impendence spectroscopy. The results demonstrate that not only the nitrogen doping level but the nitrogen type in the NGS are significant for its catalytic activity towards the [VO] 2+ /[VO 2 ] + redox couple reaction. In more detail, among four types of nitrogen species (pyridinic-N, pyrrolic-N, quaternary-N, oxidic-N) doped into the graphene lattice, quaternary-N play mainly roles for improving the catalytic activity toward the [VO] 2+ /[VO 2 ] + couple reaction

Facile fabrication of palladium-ionic liquids-nitrogen-doped graphene nanocomposites as enhanced electro-catalyst for ethanol oxidation

Science.gov (United States)

Li, Shuwen; Yang, Honglei; Ren, Ren; Ma, Jianxin; Jin, Jun; Ma, Jiantai

2015-10-01

The palladium-ionic liquids-nitrogen-doped graphene nanocomposites are facile fabricated as enhanced electro-catalyst for ethanol oxidation. First, the ionic liquids functionalized nitrogen-doping graphene nanosheets (PDIL-NGS) with few layers is synthesized through a facile and effective one-pot hydrothermal method with graphene oxide as raw material, urea as reducing-doping agents and ionic liquids (ILs) derived from 3,4,9,10-perylene tetracarboxylic acid as functional molecules. The results of systematic characterization reveal that the PDIL molecules not only can functionalize NGS by π-π stacking with no affecting the nitrogen doping but also prevent the agglomeration of NGS. More importantly, the processing performance and the property of electron transfer are remarkably enhanced duo to introducing a large number of ILs groups. Then, the enhanced electrocatalytic Pd nanoparticles are successfully anchored on PDIL-NGS by a facile and surfactant-free synthetic technique. As an anode catalyst, the novel catalyst exhibits better kinetics, more superior electrocatalytic performance, higher tolerance and electrochemical stability than the other catalysts toward ethanol electrooxidation, owing to the role of PDIL molecules. Therefore, the new catalyst is believed to have the potential use for direct alcohol fuel cells in the future and the functionalized NGS is promising useful materials applied in other fields.

[Relationship between Fe, Al oxides and stable organic carbon, nitrogen in the yellow-brown soils].

Science.gov (United States)

Heng, Li-Sha; Wang, Dai-Zhang; Jiang, Xin; Rao, Wei; Zhang, Wen-Hao; Guo, Chun-Yan; Li, Teng

2010-11-01

The stable organic carbon and nitrogen of the different particles were gained by oxidation of 6% NaOCl in the yellow-brown soils. The relationships between the contents of selective extractable Fe/Al and the stable organic carbon/nitrogen were investigated. It shown that amounts of dithionite-citrate-(Fe(d)) and oxalate-(Fe(o)) and pyrophosphate extractable (Fe(p)) were 6-60.8 g x kg(-1) and 0.13-4.8 g x kg(-1) and 0.03-0.47 g x kg(-1) in 2-250 microm particles, respectively; 43.1-170 g x kg(-1) and 5.9-14.0 g x kg(-1) and 0.28-0.78 g x kg(-1) in soils than in arid yellow-brown soils, and that of selective extractable Al are lower in the former than in the latter. Amounts of the stable organic carbon and nitrogen, higher in paddy yellow-brown soils than in arid yellow-brown soils, were 0.93-6.0 g x kg(-1) and 0.05-0.36 g x kg(-1) in 2-250 microm particles, respectively; 6.05-19.3 g x kg(-1) and 0.61-2.1 g x kg(-1) in stabilization index (SI(C) and SI(N)) of the organic carbon and nitrogen were 14.3-50.0 and 11.9-55.6 in 2-250 microm particles, respectively; 53.72-88.80 and 40.64-70.0 in soils than in paddy yellow-brown soils. The organic carbon and nitrogen are advantageously conserved in paddy yellow-brown soil. An extremely significant positive correlation of the stable organic carbon and nitrogen with selective extractable Fe/Al is observed. The most amounts between the stable organic carbon and nitrogen and selective extractable Fe/Al appear in clay particles, namely the clay particles could protect the soil organic carbon and nitrogen.

Removal of sulfur and nitrogen containing pollutants from discharge gases

Energy Technology Data Exchange (ETDEWEB)

Joubert, James I. (Pittsburgh, PA)

1986-01-01

Oxides of sulfur and of nitrogen are removed from waste gases by reaction with an unsupported copper oxide powder to form copper sulfate. The resulting copper sulfate is dissolved in water to effect separation from insoluble mineral ash and dried to form solid copper sulfate pentahydrate. This solid sulfate is thermally decomposed to finely divided copper oxide powder with high specific surface area. The copper oxide powder is recycled into contact with the waste gases requiring cleanup. A reducing gas can be introduced to convert the oxide of nitrogen pollutants to nitrogen.

Removal of sulfur and nitrogen containing pollutants from discharge gases

Energy Technology Data Exchange (ETDEWEB)

Joubert, J.I.

1985-02-08

Oxides of sulfur and of nitrogen are removed from waste gases by reaction with an unsupported copper oxide powder to form copper sulfate. The resulting copper sulfate is dissolved in water to effect separation from insoluble mineral ash and dried to form solid copper sulfate pentahydrate. This solid sulfate is thermally decomposed to finely divided copper oxide powder with high specific surface area. The copper oxide powder is recycled into contact with the waste gases requiring cleanup. A reducing gas can be introduced to convert the oxide of nitrogen pollutants to nitrogen.

The Wisconsin Test of Adult Basic Education (WITABE).

Science.gov (United States)

Pandey, Tej N.; Cleary, T. Anne

A description is given of "The Wisconsin Test of Adult Basic Education (WITABE)" which was developed specifically to measure the achievement of the individuals enrolled in the Rural Family Development (RGD) program at the University Extension, University of Wisconsin. The test is divided into three main parts or subtests: subtests 1 and…

Water-bearing explosive containing nitrogen-base salt

Energy Technology Data Exchange (ETDEWEB)

Dunglinson, C.; Lyerly, W.M.

1968-10-21

A water-bearing explosive composition consists of an oxidizing salt component, a fuel component, and water. A sensitizer is included having an oxygen balance more positive than -150%, and consisting of a salt of an inorganic oxidizing acid and of an acyclic nitrogen base having no more than 2 hydrogen atoms bonded to the basic nitrogen and up to 3 carbons per basic nitrogen, and/or of a phenyl amine. 41 claims.

General Synthesis of Transition-Metal Oxide Hollow Nanospheres/Nitrogen-Doped Graphene Hybrids by Metal-Ammine Complex Chemistry for High-Performance Lithium-Ion Batteries.

Science.gov (United States)

Chen, Jiayuan; Wu, Xiaofeng; Gong, Yan; Wang, Pengfei; Li, Wenhui; Mo, Shengpeng; Peng, Shengpan; Tan, Qiangqiang; Chen, Yunfa

2018-02-09

We present a general and facile synthesis strategy, on the basis of metal-ammine complex chemistry, for synthesizing hollow transition-metal oxides (Co 3 O 4 , NiO, CuO-Cu 2 O, and ZnO)/nitrogen-doped graphene hybrids, potentially applied in high-performance lithium-ion batteries. The oxygen-containing functional groups of graphene oxide play a prerequisite role in the formation of hollow transition-metal oxides on graphene nanosheets, and a significant hollowing process occurs only when forming metal (Co 2+ , Ni 2+ , Cu 2+ , or Zn 2+ )-ammine complex ions. Moreover, the hollowing process is well correlated with the complexing capacity between metal ions and NH 3 molecules. The significant hollowing process occurs for strong metal-ammine complex ions including Co 2+ , Ni 2+ , Cu 2+ , and Zn 2+ ions, and no hollow structures formed for weak and/or noncomplex Mn 2+ and Fe 3+ ions. Simultaneously, this novel strategy can also achieve the direct doping of nitrogen atoms into the graphene framework. The electrochemical performance of two typical hollow Co 3 O 4 or NiO/nitrogen-doped graphene hybrids was evaluated by their use as anodic materials. It was demonstrated that these unique nanostructured hybrids, in contrast with the bare counterparts, solid transition-metal oxides/nitrogen-doped graphene hybrids, perform with significantly improved specific capacity, superior rate capability, and excellent capacity retention. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Comparison of nitrogen removal rates and nitrous oxide production from enriched anaerobic ammonium oxidizing bacteria in suspended and attached growth reactors.

Science.gov (United States)

Panwivia, Supaporn; Sirvithayapakorn, Sanya; Wantawin, Chalermraj; Noophan, Pongsak Lek; Munakata-Marr, Junko

2014-01-01

Attached growth-systems for the anaerobic ammonium oxidation (anammox) process have been postulated for implementation in the field. However, information about the anammox process in attached growth-systems is limited. This study compared nitrogen removal rates and nitrous oxide (N2O) production of enriched anammox cultures in both suspended and attached growth sequencing batch reactors (SBRs). Suspended growth reactors (SBR-S) and attached growth reactors using polystyrene sponge as a medium (SBR-A) were used in these experiments. After inoculation with an enriched anammox culture, significant nitrogen removals of ammonium (NH4 (+)) and nitrite (NO2 (-)) were observed under NH4 (+):NO2 (-) ratios ranging from 1:1 to 1:2 in both types of SBRs. The specific rates of total nitrogen removal in SBR-S and SBR-A were 0.52 mg N/mg VSS-d and 0.44 mg N/mg VSS-d, respectively, at an NH4 (+):NO2 (-) ratio of 1:2. N2O production by the enriched anammox culture in both SBR-S and SBR-A was significantly higher at NH4 (+):NO2 (-) ratio of 1:2 than at NH4 (+):NO2 (-) ratios of 1:1 and 1:1.32. In addition, N2O production was higher at a pH of 6.8 than at pH 7.3, 7.8, and 8.3 in both SBR-S and SBR-A. The results of this investigation demonstrate that the anammox process may avoid N2O emission by maintaining an NH4 (+):NO2 (-) ratio of less than 1:2 and pH higher than 6.8.

An MCM modeling study of nitryl chloride (ClNO2) impacts on oxidation, ozone production and nitrogen oxide partitioning in polluted continental outflow

Science.gov (United States)

Riedel, T. P.; Wolfe, G. M.; Danas, K. T.; Gilman, J. B.; Kuster, W. C.; Bon, D. M.; Vlasenko, A.; Li, S.-M.; Williams, E. J.; Lerner, B. M.; Veres, P. R.; Roberts, J. M.; Holloway, J. S.; Lefer, B.; Brown, S. S.; Thornton, J. A.

2014-04-01

Nitryl chloride (ClNO2) is produced at night by reactions of dinitrogen pentoxide (N2O5) on chloride containing surfaces. ClNO2 is photolyzed during the morning hours after sunrise to liberate highly reactive chlorine atoms (Cl·). This chemistry takes place primarily in polluted environments where the concentrations of N2O5 precursors (nitrogen oxide radicals and ozone) are high, though it likely occurs in remote regions at lower intensities. Recent field measurements have illustrated the potential importance of ClNO2 as a daytime Cl· source and a nighttime NOx reservoir. However, the fate of the Cl· and the overall impact of ClNO2 on regional photochemistry remain poorly constrained by measurements and models. To this end, we have incorporated ClNO2 production, photolysis, and subsequent Cl· reactions into an existing master chemical mechanism (MCM version 3.2) box model framework using observational constraints from the CalNex 2010 field study. Cl· reactions with a set of alkenes and alcohols, and the simplified multiphase chemistry of N2O5, ClNO2, HOCl, ClONO2, and Cl2, none of which are currently part of the MCM, have been added to the mechanism. The presence of ClNO2 produces significant changes to oxidants, ozone, and nitrogen oxide partitioning, relative to model runs excluding ClNO2 formation. From a nighttime maximum of 1.5 ppbv ClNO2, the daytime maximum Cl· concentration reaches 1 × 105 atoms cm-3 at 07:00 model time, reacting mostly with a large suite of volatile organic compounds (VOC) to produce 2.2 times more organic peroxy radicals in the morning than in the absence of ClNO2. In the presence of several ppbv of nitrogen oxide radicals (NOx = NO + NO2), these perturbations lead to similar enhancements in hydrogen oxide radicals (HOx = OH + HO2). Neglecting contributions from HONO, the total integrated daytime radical source is 17% larger when including ClNO2, which leads to a similar enhancement in integrated ozone production of 15%. Detectable

Nitrogenous air pollutants: Chemical and biological implications

International Nuclear Information System (INIS)

Grosjean, D.

1979-01-01

Theoretical and experimental studies on the health effects and chemistry of gaseous and particulate nitrogenous air pollutants are presented. Specific topics include Fourier transform infrared studies of nitrogenous compounds, the mechanism of peroxynitric acid formation, N-nitroso compounds in the air, the chemical transformations of nitrogen oxides during the sampling of combustion products, the atmospheric chemistry of peroxy nitrates, and the effects of nitrogen dioxide on lung metabolism. Attention is also given to the interaction of nitrogen oxides and aromatic hydrocarbons under simulated atmospheric conditions, the characterization of particulate amines, the role of ammonia in atmospheric aerosol chemistry, the relationship between sulfates and nitrates and tropospheric measurements of nitric acid vapor and particulate nitrates

Hydrology, water quality, trophic status, and aquatic plants of Fowler Lake, Wisconsin

Science.gov (United States)

Hughes, P.E.

1993-01-01

The U.S. Geological Survey, in cooperation with the Fowler Lake Management District, completed a hydrologic and water-quality study of Fowler Lake in southeastern Wisconsin during calendar year 1984. Data on temperature, pH, specific conductance, and concentrations of dissolved oxygen, total phosphorus, dissolved orthophosphate phosphorus, and various nitrogen species were collected from January through November 1984. The water-quality data indicate that Fowler Lake can be classified as a mildly fertile lake with excellent water clarity as indicated by Secchi depth readings generally greater than 12 feet. Although phosphorus concentrations are generally less than 0.01 milligram per liter, the lake does produce dense stands of macrophytes during the open-water period. The lake is thermally stratified during the summer months, resulting in oxygen depletion in the deepest parts of the lake.

Learning from Wisconsin

Science.gov (United States)

Daniel, Jamie Owen

2011-01-01

Like thousands of other people from around the country and around the world, this author was heartened and inspired by the tenacity, immediacy, and creativity of the pushback by Wisconsin's public-sector unions against Governor Scott Walker's efforts to limit their collective bargaining rights. And like many others who made the trek to Madison to…

40 CFR Table 1 to Subpart Kkkk of... - Nitrogen Oxide Emission Limits for New Stationary Combustion Turbines

Science.gov (United States)

2010-07-01

... Stationary Combustion Turbines 1 Table 1 to Subpart KKKK of Part 60 Protection of Environment ENVIRONMENTAL... Standards of Performance for Stationary Combustion Turbines Pt. 60, Subpt. KKKK, Table 1 Table 1 to Subpart KKKK of Part 60—Nitrogen Oxide Emission Limits for New Stationary Combustion Turbines Combustion...

Change in gene abundance in the nitrogen biogeochemical cycle with temperature and nitrogen addition in Antarctic soils.

Science.gov (United States)

Jung, Jaejoon; Yeom, Jinki; Kim, Jisun; Han, Jiwon; Lim, Hyoun Soo; Park, Hyun; Hyun, Seunghun; Park, Woojun

2011-12-01

The microbial community (bacterial, archaeal, and fungi) and eight genes involved in the nitrogen biogeochemical cycle (nifH, nitrogen fixation; bacterial and archaeal amoA, ammonia oxidation; narG, nitrate reduction; nirS, nirK, nitrite reduction; norB, nitric oxide reduction; and nosZ, nitrous oxide reduction) were quantitatively assessed in this study, via real-time PCR with DNA extracted from three Antarctic soils. Interestingly, AOB amoA was found to be more abundant than AOA amoA in Antarctic soils. The results of microcosm studies revealed that the fungal and archaeal communities were diminished in response to warming temperatures (10 °C) and that the archaeal community was less sensitive to nitrogen addition, which suggests that those two communities are well-adapted to colder temperatures. AOA amoA and norB genes were reduced with warming temperatures. The abundance of only the nifH and nirK genes increased with both warming and the addition of nitrogen. NirS-type denitrifying bacteria outnumbered NirK-type denitrifiers regardless of the treatment used. Interestingly, dramatic increases in both NirS and NirK-types denitrifiers were observed with nitrogen addition. NirK types increase with warming, but NirS-type denitrifiers tend to be less sensitive to warming. Our findings indicated that the Antarctic microbial nitrogen cycle could be dramatically altered by temperature and nitrogen, and that warming may be detrimental to the ammonia-oxidizing archaeal community. To the best of our knowledge, this is the first report to investigate genes associated with each process of the nitrogen biogeochemical cycle in an Antarctic terrestrial soil environment. Copyright © 2011 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Decadal changes in summertime reactive oxidized nitrogen and surface ozone over the Southeast United States

Science.gov (United States)

Li, Jingyi; Mao, Jingqiu; Fiore, Arlene M.; Cohen, Ronald C.; Crounse, John D.; Teng, Alex P.; Wennberg, Paul O.; Lee, Ben H.; Lopez-Hilfiker, Felipe D.; Thornton, Joel A.; Peischl, Jeff; Pollack, Ilana B.; Ryerson, Thomas B.; Veres, Patrick; Roberts, James M.; Neuman, J. Andrew; Nowak, John B.; Wolfe, Glenn M.; Hanisco, Thomas F.; Fried, Alan; Singh, Hanwant B.; Dibb, Jack; Paulot, Fabien; Horowitz, Larry W.

2018-02-01

Widespread efforts to abate ozone (O3) smog have significantly reduced emissions of nitrogen oxides (NOx) over the past 2 decades in the Southeast US, a place heavily influenced by both anthropogenic and biogenic emissions. How reactive nitrogen speciation responds to the reduction in NOx emissions in this region remains to be elucidated. Here we exploit aircraft measurements from ICARTT (July-August 2004), SENEX (June-July 2013), and SEAC4RS (August-September 2013) and long-term ground measurement networks alongside a global chemistry-climate model to examine decadal changes in summertime reactive oxidized nitrogen (RON) and ozone over the Southeast US. We show that our model can reproduce the mean vertical profiles of major RON species and the total (NOy) in both 2004 and 2013. Among the major RON species, nitric acid (HNO3) is dominant (˜ 42-45 %), followed by NOx (31 %), total peroxy nitrates (ΣPNs; 14 %), and total alkyl nitrates (ΣANs; 9-12 %) on a regional scale. We find that most RON species, including NOx, ΣPNs, and HNO3, decline proportionally with decreasing NOx emissions in this region, leading to a similar decline in NOy. This linear response might be in part due to the nearly constant summertime supply of biogenic VOC emissions in this region. Our model captures the observed relative change in RON and surface ozone from 2004 to 2013. Model sensitivity tests indicate that further reductions of NOx emissions will lead to a continued decline in surface ozone and less frequent high-ozone events.

Reducing emission of nitrogen oxides during combustion of black coal from the Kuzbass

Energy Technology Data Exchange (ETDEWEB)

Kotler, V.R.; Lobov, G.V.; Gedike, I.A.

1983-02-01

Black coal from the Kuzbass used as fuel by the ZapSibTEhTs fossil-fuel power plant is rich in nitrogen: nitrogen content ranges from 2.8% to 3.5%. Under these conditions conventional methods of combustion cause air pollution exceeding permissible levels. A method for combustion of coal dust in stages has been successfully tested at the plant: some of the burners located in the top zone of the furnace (the BKZ-210-140F boiler) are used for air supply. From 16% to 18% of air supplied to the furnace is directed to the upper burners. Use of this system (called tertiary air supply as opposed to the secondary air system) reduced nitrogen oxide emission by 1.5 times (from 0.87 to 0.57 g/m/sup 3/). Position of nozzles used for tertiary air supply in relation to the burners used for supply of coal dust in the tangential shaped furnace is shown in a scheme. The optimum position of tertiary air supply system in relation to burners taking into account corrosion hazards as well as the hazards of reducing combustion efficiency is discussed. Recommendation on furnace design and burner position which prevent efficiency decrease and corrosion hazards are made.

Pupil Nondiscrimination Guidelines. Implementing S.118.13 of the Wisconsin Statutes and PI 9 of the Wisconsin Administrative Code. Bullein No. 8327.

Science.gov (United States)

Wisconsin State Dept. of Public Instruction, Madison.

The new S. 118.13, Wisconsin Statutes, bans pupil discrimination in any curricular, extracurricular, pupil services, recreational, or other program or activity in the State of Wisconsin on the basis of sex; race; national origin; ancestry; creed; pregnancy; marital or parental status; sexual orientation; or physical, mental, emotional, or learning…

Prediction of the production of nitrogen oxide (NOx) in turbojet engines

Science.gov (United States)

Tsague, Louis; Tsogo, Joseph; Tatietse, Thomas Tamo

Gaseous nitrogen oxides (NO+NO2=NOx) are known as atmospheric trace constituent. These gases remain a big concern despite the advances in low NOx emission technology because they play a critical role in regulating the oxidization capacity of the atmosphere according to Crutzen [1995. My life with O 3, NO x and other YZO x S; Nobel Lecture; Chemistry 1995; pp 195; December 8, 1995] . Aircraft emissions of nitrogen oxides ( NOx) are regulated by the International Civil Aviation Organization. The prediction of NOx emission in turbojet engines by combining combustion operational data produced information showing correlation between the analytical and empirical results. There is close similarity between the calculated emission index and experimental data. The correlation shows improved accuracy when the 2124 experimental data from 11 gas turbine engines are evaluated than a previous semi empirical correlation approach proposed by Pearce et al. [1993. The prediction of thermal NOx in gas turbine exhausts. Eleventh International Symposium on Air Breathing Engines, Tokyo, 1993, pp. 6-9]. The new method we propose predict the production of NOx with far more improved accuracy than previous methods. Since a turbojet engine works in an atmosphere where temperature, pressure and humidity change frequently, a correction factor is developed with standard atmospheric laws and some correlations taken from scientific literature [Swartwelder, M., 2000. Aerospace engineering 410 Term Project performance analysis, November 17, 2000, pp. 2-5; Reed, J.A. Java Gas Turbine Simulator Documentation. pp. 4-5]. The new correction factor is validated with experimental observations from 19 turbojet engines cruising at altitudes of 9 and 13 km given in the ICAO repertory [Middleton, D., 1992. Appendix K (FAA/SETA). Section 1: Boeing Method Two Indices, 1992, pp. 2-3]. This correction factor will enable the prediction of cruise NOx emissions of turbojet engines at cruising speeds. The ICAO

Effects of contrasting catch crops on nitrogen availability and nitrous oxide emissions in an organic cropping system

DEFF Research Database (Denmark)

Li, Xiaoxi; Petersen, Søren O; Sørensen, Peter

2015-01-01

Legume-based catch crops (LBCCs) may act as an important source of nitrogen (N) in organic crop rotations because of biological N fixation. However, the potential risk of high nitrous oxide (N2O) emissions needs to be taken into account when including LBCCs in crop rotations. Here, we report...

77 FR 59921 - Wisconsin Public Service Corporation; Notice of Environmental Site Review

Science.gov (United States)

2012-10-01

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 1940-000 Wisconsin; Project No. 1966-000 Wisconsin] Wisconsin Public Service Corporation; Notice of Environmental Site Review In anticipation of the filing of Notices of Intent (NOI) and Pre- Application Documents for the Grandfather Falls Hydroelectric Project No. 1966 and...

University of Wisconsin - Extension

Science.gov (United States)

... to know how to advance an innovative tech idea I want to know more about agricultural resources available in Wisconsin I want to learn how I can get training and support for my small business I want to learn how I can get ...

Undergraduate Research and Economic Development: A Systems Approach in Wisconsin

Science.gov (United States)

Van Galen, Dean; Schneider-Rebozo, Lissa; Havholm, Karen; Andrews, Kris

2015-01-01

This chapter presents the state of Wisconsin and the University of Wisconsin System as an ongoing case study for best practices in systematic, intentional, statewide programming and initiatives connecting undergraduate research and economic development.

Influence of tropical leaf litter on nitrogen mineralization and community structure of ammonia-oxidizing bacteria

OpenAIRE

Diallo, M. D.; Guisse, A.; Sall, S. N.; Dick, R. P.; Assigbetsé, Komi; Dieng, A. L.; Chotte, Jean-Luc

2015-01-01

Description of the subject. The present study concerns the relationships among leaf litter decomposition, substrate quality, ammonia-oxidizing bacteria (AOB) community composition and nitrogen (N) availability. Decomposition of organic matter affects the biogeochemical cycling of carbon (C) and N. Since the composition of the soil microbial community can alter the physiological capacity of the community, it is timely to study the litter quality effect on N dynamic in ecosystems. Objectives. T...

Indoor-outdoor nitric oxide and nitrogen dioxide concentrations at three sites in Riyadh, Saudi Arabia

Energy Technology Data Exchange (ETDEWEB)

Rowe, D.R. (D.R. Rowe Engineering Services, Inc., Bowling Green, KY (United States)); Al-Dhowalia, K.H.; Mansour, M.E. (King Saud Univ., Riyadh (Saudi Arabia))

1991-08-01

The objective of this study was to evaluate the nitric oxide and nitrogen oxide concentrations indoors and outdoors at three sites in Riyadh, Saudi Arabia. Results show that the outdoor and indoor concentrations for NO were at least 270 and 16 times the reported average worldwide NO concentrations, respectively. The NO(sub 2) concentrations were about 14 times reported outdoor worldwide levels; however, NO(sub 2) concentrations indoors were generally below those reported in the literature. The data presented, in combination with information presented in previous articles, will provide a valuable background database for use in dispersion models to determine the effect of the Kuwaiti oil well fires on the air quality of Riyadh.

76 FR 29180 - Approval and Promulgation of Air Quality Implementation Plans; Pennsylvania; Control of Nitrogen...

Science.gov (United States)

2011-05-20

... Promulgation of Air Quality Implementation Plans; Pennsylvania; Control of Nitrogen Oxides Emissions From... Pennsylvania. This revision pertains to the control of nitrogen oxide (NO X ) emissions from Portland cement... oxidation of chemically-bound nitrogen in the fuel and by thermal fixation of nitrogen in the combustion air...

The Effect of Fuel Quality on Carbon Dioxide and Nitrogen Oxide Emissions, While Burning Biomass and RDF

Science.gov (United States)

Kalnacs, J.; Bendere, R.; Murasovs, A.; Arina, D.; Antipovs, A.; Kalnacs, A.; Sprince, L.

2018-02-01

The article analyses the variations in carbon dioxide emission factor depending on parameters characterising biomass and RDF (refuse-derived fuel). The influence of moisture, ash content, heat of combustion, carbon and nitrogen content on the amount of emission factors has been reviewed, by determining their average values. The options for the improvement of the fuel to result in reduced emissions of carbon dioxide and nitrogen oxide have been analysed. Systematic measurements of biomass parameters have been performed, by determining their average values, seasonal limits of variations in these parameters and their mutual relations. Typical average values of RDF parameters and limits of variations have been determined.

Teaching Environmental Education to Wisconsin Teachers: A Review of University Course Materials.

Science.gov (United States)

Sanera, Michael

1997-01-01

This report contains a study done at the request of the Wisconsin Policy Research Institute, which studies public policy issues affecting the state of Wisconsin. The purpose of this study was to examine the content of environmental education (EE) materials used in courses required for teacher certification in Wisconsin to see if the knowledge and…

Decadal changes in summertime reactive oxidized nitrogen and surface ozone over the Southeast United States

Directory of Open Access Journals (Sweden)

J. Li

2018-02-01

Full Text Available Widespread efforts to abate ozone (O3 smog have significantly reduced emissions of nitrogen oxides (NOx over the past 2 decades in the Southeast US, a place heavily influenced by both anthropogenic and biogenic emissions. How reactive nitrogen speciation responds to the reduction in NOx emissions in this region remains to be elucidated. Here we exploit aircraft measurements from ICARTT (July–August 2004, SENEX (June–July 2013, and SEAC4RS (August–September 2013 and long-term ground measurement networks alongside a global chemistry–climate model to examine decadal changes in summertime reactive oxidized nitrogen (RON and ozone over the Southeast US. We show that our model can reproduce the mean vertical profiles of major RON species and the total (NOy in both 2004 and 2013. Among the major RON species, nitric acid (HNO3 is dominant (∼ 42–45 %, followed by NOx (31 %, total peroxy nitrates (ΣPNs; 14 %, and total alkyl nitrates (ΣANs; 9–12 % on a regional scale. We find that most RON species, including NOx, ΣPNs, and HNO3, decline proportionally with decreasing NOx emissions in this region, leading to a similar decline in NOy. This linear response might be in part due to the nearly constant summertime supply of biogenic VOC emissions in this region. Our model captures the observed relative change in RON and surface ozone from 2004 to 2013. Model sensitivity tests indicate that further reductions of NOx emissions will lead to a continued decline in surface ozone and less frequent high-ozone events.

Fluxes of methane and nitrogen oxides in various boreal mire ecosystems. Effects of land-use activities and environmental changes

Energy Technology Data Exchange (ETDEWEB)

Martikainen, P J; Nykaenen, H; Regina, K [National Public Health Inst., Kuopio (Finland). Lab. of Environmental Microbiology; Alm, J; Silvola, J [Joensuu Univ. (Finland). Dept. of Biology

1997-12-31

Atmospheric impact of peatlands is a sum of their gas fluxes. In contrast to carbon dioxide, peatlands are net sources for methane (CH{sub 4}). Methane is an end product in the anaerobic decomposition processes and it has greater capacity to absorb infrared radiation than carbon dioxide. Most of the data on the CH{sub 4} release from northern peatlands is from North America. The total amount of methane released from wetlands is calculated to be 110 Tg yr{sup -1} of which 34 percent (38 Tg yr{sup -1}) is estimated to be emitted from the northern peatlands. Peat with high content of nitrogen is a potential source for gaseous nitrogen oxides, i.e. nitrous oxide (N{sub 2}O) and nitric oxide (NO). However, the importance of peatlands in producing these trace gases is poorly known. Nitrous oxide and nitric oxide are important components in the atmospheric chemistry and N{sub 2}O also is an effective greenhouse gas. Land-use activities and environmental changes can affect the atmospheric impacts of peatlands by modifying their biogeochemistry. This article presents a short summary of the studies whose objectives were: (1) to measure fluxes of CH{sub 4} and N{sub 2}O on wide range of natural mires in Finland, (2) to study the short- and long-term changes in fluxes of CH{sub 4}, N{sub 2}O and NO on boreal peatlands after lowering their water table. Peatlands used for agriculture, forestry and peat mining were included in the studies. The results from mires drained for forestry may reflect the possible changes in the trace gas fluxes if water table will drop in the northern peatlands as a result of drier climate, (3) to study the effects of nitrogen load on the fluxes of CH{sub 4}, N{sub 2}O and NO, (4) to identify the microbiological processes important for the fluxes of N{sub 2}O, NO and CH{sub 4}, and to study the environmental factors regulating these microbial processes

Fluxes of methane and nitrogen oxides in various boreal mire ecosystems. Effects of land-use activities and environmental changes

Energy Technology Data Exchange (ETDEWEB)

Martikainen, P.J.; Nykaenen, H.; Regina, K. [National Public Health Inst., Kuopio (Finland). Lab. of Environmental Microbiology; Alm, J.; Silvola, J. [Joensuu Univ. (Finland). Dept. of Biology

1996-12-31

Atmospheric impact of peatlands is a sum of their gas fluxes. In contrast to carbon dioxide, peatlands are net sources for methane (CH{sub 4}). Methane is an end product in the anaerobic decomposition processes and it has greater capacity to absorb infrared radiation than carbon dioxide. Most of the data on the CH{sub 4} release from northern peatlands is from North America. The total amount of methane released from wetlands is calculated to be 110 Tg yr{sup -1} of which 34 percent (38 Tg yr{sup -1}) is estimated to be emitted from the northern peatlands. Peat with high content of nitrogen is a potential source for gaseous nitrogen oxides, i.e. nitrous oxide (N{sub 2}O) and nitric oxide (NO). However, the importance of peatlands in producing these trace gases is poorly known. Nitrous oxide and nitric oxide are important components in the atmospheric chemistry and N{sub 2}O also is an effective greenhouse gas. Land-use activities and environmental changes can affect the atmospheric impacts of peatlands by modifying their biogeochemistry. This article presents a short summary of the studies whose objectives were: (1) to measure fluxes of CH{sub 4} and N{sub 2}O on wide range of natural mires in Finland, (2) to study the short- and long-term changes in fluxes of CH{sub 4}, N{sub 2}O and NO on boreal peatlands after lowering their water table. Peatlands used for agriculture, forestry and peat mining were included in the studies. The results from mires drained for forestry may reflect the possible changes in the trace gas fluxes if water table will drop in the northern peatlands as a result of drier climate, (3) to study the effects of nitrogen load on the fluxes of CH{sub 4}, N{sub 2}O and NO, (4) to identify the microbiological processes important for the fluxes of N{sub 2}O, NO and CH{sub 4}, and to study the environmental factors regulating these microbial processes

Fluxes of methane and nitrogen oxides in various boreal mire ecosystems. Effects of land-use activities and environmental changes

International Nuclear Information System (INIS)

Martikainen, P.J.; Nykaenen, H.; Regina, K.; Alm, J.; Silvola, J.

1996-01-01

Atmospheric impact of peatlands is a sum of their gas fluxes. In contrast to carbon dioxide, peatlands are net sources for methane (CH 4 ). Methane is an end product in the anaerobic decomposition processes and it has greater capacity to absorb infrared radiation than carbon dioxide. Most of the data on the CH 4 release from northern peatlands is from North America. The total amount of methane released from wetlands is calculated to be 110 Tg yr -1 of which 34 percent (38 Tg yr -1 ) is estimated to be emitted from the northern peatlands. Peat with high content of nitrogen is a potential source for gaseous nitrogen oxides, i.e. nitrous oxide (N 2 O) and nitric oxide (NO). However, the importance of peatlands in producing these trace gases is poorly known. Nitrous oxide and nitric oxide are important components in the atmospheric chemistry and N 2 O also is an effective greenhouse gas. Land-use activities and environmental changes can affect the atmospheric impacts of peatlands by modifying their biogeochemistry. This article presents a short summary of the studies whose objectives were: (1) to measure fluxes of CH 4 and N 2 O on wide range of natural mires in Finland, (2) to study the short- and long-term changes in fluxes of CH 4 , N 2 O and NO on boreal peatlands after lowering their water table. Peatlands used for agriculture, forestry and peat mining were included in the studies. The results from mires drained for forestry may reflect the possible changes in the trace gas fluxes if water table will drop in the northern peatlands as a result of drier climate, (3) to study the effects of nitrogen load on the fluxes of CH 4 , N 2 O and NO, (4) to identify the microbiological processes important for the fluxes of N 2 O, NO and CH 4 , and to study the environmental factors regulating these microbial processes

Synthesis, characterization and photo catalytic activity of titanium oxide modified with nitrogen; Sintesis, caracterizacion y actividad fotocatalitica de oxido de titanio modificado con nitrogeno

Energy Technology Data Exchange (ETDEWEB)

Hernandez Enriquez, J. M.; Garcia Alamilla, R.; Garcia Serrano, L. A.; Cueto Hernandez, A.

2011-07-01

Titanium oxides (TiO{sub 2}) were synthesized by precipitation of titanium tetrachloride (TiCl{sub 4}) using ammonium hydroxide (NH{sub 4}OH). The synthesized materials were characterized by means of nitrogen physisorption, X-ray diffraction, infrared spectroscopy, U.V.-visible diffuse reflectance spectroscopy and the photo catalytic activity of the samples were measured by the degradation of the methyl orange. By means of this synthesis method we have doped the titanium oxide structure with nitrogen (N-TiO{sub 2}), stabilizing the anatase phase and obtaining meso porous and nanocrystalline materials. The titanium oxide with higher specific surface area (132 m{sup 2}/g) degraded the azo-compound to 100% in 180 min of reaction. (Author) 33 refs.

Alumina- and titania-based monolithic catalysts for low temperature selective catalytic reduction of nitrogen oxides

International Nuclear Information System (INIS)

Blanco, J.; Avila, P.; Suarez, S.; Martin, J.A.; Knapp, C.

2000-01-01

The selective catalytic reduction of NO+NO 2 (NO x ) at low temperature (180-230C) with ammonia has been investigated with copper-nickel and vanadium oxides supported on titania and alumina monoliths. The influence of the operating temperature, as well as NH 3 /NO x and NO/NO 2 inlet ratios has been studied. High NO x conversions were obtained at operating conditions similar to those used in industrial scale units with all the catalysts. Reaction temperature, ammonia and nitrogen dioxide inlet concentration increased the N 2 O formation with the copper-nickel catalysts, while no increase was observed with the vanadium catalysts. The vanadium-titania catalyst exhibited the highest DeNO x activity, with no detectable ammonia slip and a low N 2 O formation when NH 3 /NO x inlet ratio was kept below 0.8. TPR results of this catalyst with NO/NH 3 /O 2 , NO 2 /NH 3 /O 2 and NO/NO 2 /NH 3 /O 2 feed mixtures indicated that the presence of NO 2 as the only nitrogen oxide increases the quantity of adsorbed species, which seem to be responsible for N 2 O formation. When NO was also present, N 2 O formation was not observed

Electrochemical oxidation of nitrogen-heterocyclic compounds at boron-doped diamond electrode.

Science.gov (United States)

Xing, Xuan; Zhu, Xiuping; Li, Hongna; Jiang, Yi; Ni, Jinren

2012-01-01

Nitrogen-heterocyclic compounds (NHCs) are toxic and bio-refractory contaminants widely spread in environment. This study investigated electrochemical degradation of NHCs at boron-doped diamond (BDD) anode with particular attention to the effect of different number and position of nitrogen atoms in molecular structure. Five classical NHCs with similar structures including indole (ID), quinoline (QL), isoquinoline (IQL), benzotriazole (BT) and benzimidazole (BM) were selected as the target compounds. Results of bulk electrolysis showed that degradation of all NHCs was fit to a pseudo first-order equation. The five compounds were degraded with the following sequence: ID>QL>IQL>BT>BM in terms of their rates of oxidation. Quantum chemical calculation was combined with experimental results to describe the degradation character of NHCs at BDD anode. A linear relationship between degradation rate and delocalization energy was observed, which demonstrated that electronic charge was redistributed through the conjugation system and accumulated at the active sites under the attack of hydroxyl radicals produced at BDD anode. Moreover, atom charge was calculated by semi empirical PM3 method and active sites of NHCs were identified respectively. Analysis of intermediates by GC-MS showed agreement with calculation results. Copyright © 2011 Elsevier Ltd. All rights reserved.

Quantification of Lightning-induced Nitrogen Oxides in CMAQ and the Assessment of its impact on Ground-level Air Quality

Science.gov (United States)

Lightning-induced nitrogen oxides (LNOX), in the presence of sunlight, volatile organic compounds and water, can be a relatively large but uncertain source for ozone (O3) and hydroxyl radical (OH) in the atmosphere. Using lightning flash data from the National Lightning Detection...

Sulfonamide antibiotic removal and nitrogen recovery from synthetic urine by the combination of rotating advanced oxidation contactor and methylene urea synthesis process

OpenAIRE

Fukahori, S.; Fujiwara, T.; Ito, R.; Funamizu, N.

2015-01-01

The combination of nitrogen recovery and pharmaceutical removal processes for livestock urine treatment were investigated to suppress the discharge of pollutants and recover nitrogen as resources. We combined methylene urea synthesis from urea and adsorption and photocatalytic decomposition of sulfonamide antibiotic using rotating advanced oxidation contactor (RAOC) contained for obtaining both safe fertilizer and reclaimed water. The methylene urea synthesis could recover urea in synthetic u...

Water Use in Wisconsin, 2005

Science.gov (United States)

Buchwald, Cheryl A.

2009-01-01

The U.S. Geological Survey (USGS) Wisconsin Water Science Center is responsible for presenting data collected or estimated for water withdrawals and diversions every 5 years to the National Water-Use Information Program (NWUIP). This program serves many purposes such as quantifying how much, where, and for what purpose water is used; tracking and documenting water-use trends and changes; and providing these data to other agencies to support hydrologic projects. In 2005, data at both the county and subbasin levels were compiled into the USGS national water-use database system; these data are published in a statewide summary report and a national circular. This publication, Water Use in Wisconsin, 2005, presents the water-use estimates for 2005; this publication also describes how these water-use data were determined (including assumptions used), limitations of using these data, and trends in water-use data presented to the NWUIP. Estimates of water use in Wisconsin indicate that about 8,608 million gallons per day (Mgal/d) were withdrawn during 2005. Of this amount, about 7,622 Mgal/d (89 percent) were from surface-water sources and about 986 Mgal/d (11 percent) were from ground-water sources. Surface water used for cooling at thermoelectric-power plants constituted the largest portion of daily use at 6,898 Mgal/d. Water provided by public-supply water utilities is the second largest use of water and totaled 552 Mgal/d. Public supply served approximately 71 percent of the estimated 2005 Wisconsin population of 5.54 million people; two counties - Milwaukee and Dane - accounted for more than one-third of the public-supply withdrawal. Industrial and irrigation were the next major water uses at 471 and 402 Mgal/d, respectively. Non-irrigational agricultural (livestock and aquaculture) accounted for approximately 155 Mgal/d and is similar to the combined withdrawal for the remaining water-use categories of domestic, commercial, and mining (131 Mgal/d). Data on water use

Wisconsin State Briefing Book for low-level radioactive waste management

Energy Technology Data Exchange (ETDEWEB)

1980-11-01

The Wisconsin State Briefing Book is one of a series of state briefing books on low-level radioactive waste management practices. It has been prepared to assist state and federal agency officials in planning for safe low-level radioactive waste disposal. The report contains a profile of low-level radioactive waste generators in Wisconsin. The profile is the result of a survey of NRC licensees in Wisconsin. The briefing book also contains a comprehensive assessment of low-level radioactive waste management issues and concerns as defined by all major interested parties including industry, government, the media, and interest groups. The assessment was developed through personal communications with representatives of interested parties, and through a review of media sources. Lastly, the briefing book provides demographic and socioeconomic data and a discussion of relevant government agencies and activities, all of which may impact waste management practices in Wisconsin.

Wisconsin State Briefing Book for low-level radioactive waste management

International Nuclear Information System (INIS)

1980-11-01

The Wisconsin State Briefing Book is one of a series of state briefing books on low-level radioactive waste management practices. It has been prepared to assist state and federal agency officials in planning for safe low-level radioactive waste disposal. The report contains a profile of low-level radioactive waste generators in Wisconsin. The profile is the result of a survey of NRC licensees in Wisconsin. The briefing book also contains a comprehensive assessment of low-level radioactive waste management issues and concerns as defined by all major interested parties including industry, government, the media, and interest groups. The assessment was developed through personal communications with representatives of interested parties, and through a review of media sources. Lastly, the briefing book provides demographic and socioeconomic data and a discussion of relevant government agencies and activities, all of which may impact waste management practices in Wisconsin

Atmospheric cycles of nitrogen oxides and ammonia. [source strengths and destruction rates

Science.gov (United States)

Bottger, A.; Ehhalt, D. H.; Gravenhorst, G.

1981-01-01

The atmospheric cycles of nitrogenous trace compounds for the Northern and Southern Hemispheres are discussed. Source strengths and destruction rates for the nitrogen oxides: NO, NO2 and HNO3 -(NOX) and ammonia (NH3) are given as a function of latitude over continents and oceans. The global amounts of NOX-N and NH3-N produced annually in the period 1950 to 1975 (34 + 5 x one trillion g NOx-N/yr and 29 + or - 6 x one trillion g NH3-N/yr) are much less than previously assumed. Globally, natural and anthropogenic emissions are of similar magnitude. The NOx emission from anthropogenic sources is 1.5 times that from natural processes in the Northern Hemisphere, whereas in the Southern Hemisphere, it is a factor of 3 or 4 less. More than 80% of atmospheric ammonia seems to be derived from excrements of domestic animals, mostly by bulk deposition: 24 + or - 9 x one trillion g NO3 -N/yr and 21 + or - 9 x one trillion g NH4+-N/yr. Another fraction may be removed by absorption on vegetation and soils.

77 FR 7149 - Notice of Workshop and Call for Information on Integrated Science Assessment for Oxides of Nitrogen

Science.gov (United States)

2012-02-10

... existing air quality criteria to reflect advances in scientific knowledge on the effects of the pollutant... part of the review of the primary National Ambient Air Quality Standards (NAAQS) for oxides of nitrogen... assist the EPA in developing and refining the scientific information base for the review of the NO 2...

Wisconsin EE Mandates: The Bad News and the Good News.

Science.gov (United States)

Lane, Jennie; And Others

1996-01-01

Examines Wisconsin teachers' perceived competencies in, attitudes toward, and amount of class time devoted to teaching about the environment. Discusses the effects of Wisconsin environmental education mandates concerning preservice preparation in environmental education and K-12 environmental education curriculum plans. Identifies areas where the…

Potentiality of hydroxylamine nitrate as a scrubbing reagent to trap iodine and nitrogen oxides in nuclear spent fuel dissolution off-gas

International Nuclear Information System (INIS)

Cau Dit Coumes, C.

1998-01-01

The management of low and medium-level radioactive effluents, newly implemented in Cogema-La Hague plants, foresee to replace tarring by vitrification. This process change imposes to greatly reduce the saline content of the effluents and in particular the sodium content to improve the leaching resistance of glass. Studies have been carried out to find a substitute to soda, today used to trap iodine and nitrogen oxides by counterflow washing of spent fuel dissolution gases. The aim of this work is to evaluate the potentialities of hydroxylamine nitrate. After a presentation of the chemistry of iodine and inorganic nitrogenous compounds, the reactions susceptible to take place inside the washing column are identified. An experimental study of of the reactions of hydroxylamine with molecular iodine, methyl iodide, nitrous acid, and nitrogen oxides (NO, NO 2 , N 2 O 3 and N 2 O 4 ) has permitted to precise in each case, the products, the stoichiometry, the kinetics and the reaction mechanisms. The results obtained show that only an hydroxylamine acid solution allows to simultaneously reduce iodine into iodide and to eliminate the nitrous acid formed by the hydrolysis of nitrogen oxides. Two models of the iodine/iodide/nitrous acid/hydroxylamine reaction system are proposed in acid environment. The first one, established from the kinetic laws of the reactions involved, has only a restricted domain of validity. The second one, obtained by applying the experimental research methodology, is valid over a wider experimental domain and has been used to determine the favorable conditions for the simultaneous and fast reduction of iodine and nitrous acid by hydroxylamine. (J.S.)

Satellite-based emission constraint for nitrogen oxides: Capability and uncertainty

Science.gov (United States)

Lin, J.; McElroy, M. B.; Boersma, F.; Nielsen, C.; Zhao, Y.; Lei, Y.; Liu, Y.; Zhang, Q.; Liu, Z.; Liu, H.; Mao, J.; Zhuang, G.; Roozendael, M.; Martin, R.; Wang, P.; Spurr, R. J.; Sneep, M.; Stammes, P.; Clemer, K.; Irie, H.

2013-12-01

Vertical column densities (VCDs) of tropospheric nitrogen dioxide (NO2) retrieved from satellite remote sensing have been employed widely to constrain emissions of nitrogen oxides (NOx). A major strength of satellite-based emission constraint is analysis of emission trends and variability, while a crucial limitation is errors both in satellite NO2 data and in model simulations relating NOx emissions to NO2 columns. Through a series of studies, we have explored these aspects over China. We separate anthropogenic from natural sources of NOx by exploiting their different seasonality. We infer trends of NOx emissions in recent years and effects of a variety of socioeconomic events at different spatiotemporal scales including the general economic growth, global financial crisis, Chinese New Year, and Beijing Olympics. We further investigate the impact of growing NOx emissions on particulate matter (PM) pollution in China. As part of recent developments, we identify and correct errors in both satellite NO2 retrieval and model simulation that ultimately affect NOx emission constraint. We improve the treatments of aerosol optical effects, clouds and surface reflectance in the NO2 retrieval process, using as reference ground-based MAX-DOAS measurements to evaluate the improved retrieval results. We analyze the sensitivity of simulated NO2 to errors in the model representation of major meteorological and chemical processes with a subsequent correction of model bias. Future studies will implement these improvements to re-constrain NOx emissions.

Nitrogen loading and nitrous oxide emissions from a river with multiple hydroelectric reservoirs.

Science.gov (United States)

Chen, Jinsong; Cao, Wenzhi; Cao, Di; Huang, Zheng; Liang, Ying

2015-05-01

River networks receive a large fraction of the anthropogenic nitrogen applied to river catchments. The different impacts of the stream nitrogen (N) loading on nitrous oxide (N2O) emissions from various of aquatic ecosystems are still unknown. In this study, direct measurements of water-air interface N2O exchange in different water bodies were conducted. Results showed that the water-air interface N2O exchange from tributaries, hydropower station reservoirs, a main stream, and its estuary were 10.14 ± 13.51, 15.64 ± 10.72, 27.59 ± 20.99, and 15.98 ± 12.26 µg N2O-N m(-2) h(-1), respectively, indicating the strong impacts of human activities on N2O emission rates. The water NO2 (-)-N values predicted the dissolved N2O concentrations better than did the NO3 (-)-N and NH4 (+)-N values, indicating strong denitrification and nitrification processes. The dissolved inorganic N explained 36 % of the variations in the N2O emissions for the whole river network.

Oxidation of urea-derived nitrogen by thaumarchaeota-dominated marine nitrifying communities.

Science.gov (United States)

Tolar, Bradley B; Wallsgrove, Natalie J; Popp, Brian N; Hollibaugh, James T

2017-12-01

Urea nitrogen has been proposed to contribute significantly to nitrification by marine thaumarchaeotes. These inferences are based on distributions of thaumarchaeote urease genes rather than activity measurements. We found that ammonia oxidation rates were always higher than oxidation rates of urea-derived N in samples from coastal Georgia, USA (means ± SEM: 382 ± 35 versus 73 ± 24 nmol L -1  d -1 , Mann-Whitney U-test p  0.05). Urea-derived N was relatively more important in samples from Antarctic continental shelf waters, though the difference was not statistically significant (19.4 ± 4.8 versus 12.0 ± 2.7 nmol L -1  d -1 , p > 0.05). We found only weak correlations between oxidation rates of urea-derived N and the abundance or transcription of putative Thaumarchaeota ureC genes. Dependence on urea-derived N does not appear to be directly related to pH or ammonium concentrations. Competition experiments and release of 15 NH 3 suggest that urea is hydrolyzed to ammonia intracellularly, then a portion is lost to the dissolved pool. The contribution of urea-derived N to nitrification appears to be minor in temperate coastal waters, but may represent a significant portion of the nitrification flux in Antarctic coastal waters. © 2016 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.

Keeping the heart in balance: the functional interactions of myoglobin with nitrogen oxides

DEFF Research Database (Denmark)

Flögel, Ulrich; Fago, Angela; Rassaf, Tienush

2010-01-01

in the heart. By a dynamic cycle, in which a decrease in tissue O2 tension drives the conversion of Mb from being a NO scavenger under normoxia to a NO producer during hypoxia, mitochondrial respiration is reversibly adapted to the intracellular O2 tension. Therefore, Mb may act as an important O2 sensor...... through which NO can regulate muscle energetics and function. As Mb is widespread throughout the fauna, the diverse oxygen-dependent interactions between Mb and nitrogen oxides may not only be of relevance for mammals but also for other vertebrates as evidenced by comparable phenotypes of ‘artificial...

Tracking nitrogen oxides, nitrous acid, and nitric acid from biomass burning

Science.gov (United States)

Chai, J.; Miller, D. J.; Scheuer, E. M.; Dibb, J. E.; Hastings, M. G.

2017-12-01

Biomass burning emissions are an important source of atmospheric nitrogen oxides (NOx = NO + NO2) and nitrous acid (HONO), which play important roles in atmosphere oxidation capacity (hydroxyl radical and ozone formation) and have severe impacts on air quality and climate in the presence of sunlight and volatile organic compounds. However, tracking NOx and HONO and their chemistry in the atmosphere based on concentration alone is challenging. Isotopic analysis provides a potential tracking tool. In this study, we measured the nitrogen isotopic composition (δ15N) of NOx (NO + NO2) and HONO, and soluble HONO and HNO3 during the Fire Influence on Regional and Global Environments Experiment (FIREX) laboratory experiments at the Missoula Fire Laboratory. Our newly developed and validated annular denuder system (ADS) enabled us to effectively trap HONO prior to a NOx collection system in series for isotopic analysis. In total we investigated 25 "stack" fires of various biomass materials where the emissions were measured within a few seconds of production by the fire. HONO concentration was measured in parallel using mist chamber/ion chromatography (MC/IC). The recovered mean HONO concentrations from ADS during the burn of each fire agree well with that measured via MC/IC. δ15N-NOx ranged from -4.3 ‰ to + 7.0 ‰ with a median of 0.7 ‰. Combined with a similar, recent study by our group [Fibiger et al., ES&T, 2017] the δ15N-NOx follows a linear relationship with δ15N-biomass (δ15N-NOx =0.94 x δ15N-biomass +1.98; R2=0.72). δ15N-HONO ranged from -5.3 to +8.3 ‰ with a median of 1.4 ‰. While both HONO and NOx are sourced from N in the biomass fuel, the secondary formation of HONO likely induces fractionation of the N that leads to the difference between δ15N-NOx and δ15N-HONO. We found a correlation of δ15N-HONO= 0.86 x δ15N-NOx + 0.52 (R2=0.55), which can potentially be used to track the chemistry of HONO formation following fire emissions. The methods

Residential Energy Efficiency Potential: Wisconsin

Energy Technology Data Exchange (ETDEWEB)

Wilson, Eric J [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2017-11-27

Energy used by Wisconsin single-family homes that can be saved through cost-effective improvements. Prepared by Eric Wilson and Noel Merket, NREL, and Erin Boyd, U.S. Department of Energy Office of Energy Policy and Systems Analysis.

Nitrogen removal and intentional nitrous oxide production from reject water in a coupled nitritation/nitrous denitritation system under real feed-stream conditions.

Science.gov (United States)

Weißbach, Max; Thiel, Paul; Drewes, Jörg E; Koch, Konrad

2018-05-01

A Coupled Aerobic-anoxic Nitrous Decomposition Operation (CANDO) was performed over five months to investigate the performance and dynamics of nitrogen elimination and nitrous oxide production from digester reject water under real feed-stream conditions. A 93% conversion of ammonium to nitrite could be maintained for adapted seed sludge in the first stage (nitritation). The second stage (nitrous denitritation), inoculated with conventional activated sludge, achieved a conversion of 70% of nitrite to nitrous oxide after only 12 cycles of operation. The development of an alternative feeding strategy and the addition of a coagulant (FeCl 3 ) facilitated stable operation and process intensification. Under steady-state conditions, nitrite was reliably eliminated and different nitrous oxide harvesting strategies were assessed. Applying continuous removal increased N 2 O yields by 16% compared to the application of a dedicated stripping phase. These results demonstrate the feasible application of the CANDO process for nitrogen removal and energy recovery from ammonia rich wastewater. Copyright © 2018 Elsevier Ltd. All rights reserved.

The nitrogen cycle.

Science.gov (United States)

Stein, Lisa Y; Klotz, Martin G

2016-02-08

Nitrogen is the fourth most abundant element in cellular biomass, and it comprises the majority of Earth's atmosphere. The interchange between inert dinitrogen gas (N2) in the extant atmosphere and 'reactive nitrogen' (those nitrogen compounds that support, or are products of, cellular metabolism and growth) is entirely controlled by microbial activities. This was not the case, however, in the primordial atmosphere, when abiotic reactions likely played a significant role in the inter-transformation of nitrogen oxides. Although such abiotic reactions are still important, the extant nitrogen cycle is driven by reductive fixation of dinitrogen and an enzyme inventory that facilitates dinitrogen-producing reactions. Prior to the advent of the Haber-Bosch process (the industrial fixation of N2 into ammonia, NH3) in 1909, nearly all of the reactive nitrogen in the biosphere was generated and recycled by microorganisms. Although the Haber-Bosch process more than quadrupled the productivity of agricultural crops, chemical fertilizers and other anthropogenic sources of fixed nitrogen now far exceed natural contributions, leading to unprecedented environmental degradation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Defect pair formation in fluorine and nitrogen codoped TiO2

Science.gov (United States)

Kordatos, A.; Kelaidis, N.; Chroneos, A.

2018-04-01

Titanium oxide is extensively investigated because of its high chemical stability and its photocatalytic properties; nevertheless, the large band gap limits its activity to a small portion of the solar spectrum. Nitrogen and fluorine codoping is an efficient defect engineering strategy to increase the photocatalytic activity of titanium oxide. In the present study, we apply density functional theory to investigate the interaction of nitrogen with fluorine and the formation of defect pairs. We show that in fluorine and nitrogen codoped titanium oxide, the FiNi, FONi, and FiNTi defects can form. Their impact on the electronic structure of titanium oxide is discussed.

76 FR 68638 - Approval and Promulgation of Air Quality Implementation Plans; Virginia; Revision to Nitrogen...

Science.gov (United States)

2011-11-07

... Promulgation of Air Quality Implementation Plans; Virginia; Revision to Nitrogen Oxides Budget Trading Program... pertains to regulatory language in its nitrogen oxides (NO X ) Budget Trading Program that inadvertently..., Nitrogen dioxide, Ozone, Sulfur oxides. Dated: October 25, 2011. W.C. Early, Acting Regional Administrator...

75 FR 31711 - Approval and Promulgation of Air Quality Implementation Plans; Delaware; Control of Nitrogen...

Science.gov (United States)

2010-06-04

... Promulgation of Air Quality Implementation Plans; Delaware; Control of Nitrogen Oxide Emissions From Industrial... controlling nitrogen oxide (NOx) emissions from industrial boilers. This action is being taken under the Clean...--Control of Nitrogen Oxide Emissions from Industrial Boilers and Process Heaters at Petroleum Refineries in...

75 FR 12168 - Approval and Promulgation of Air Quality Implementation Plans; Delaware; Control of Nitrogen...

Science.gov (United States)

2010-03-15

... Promulgation of Air Quality Implementation Plans; Delaware; Control of Nitrogen Oxide Emissions From Industrial... the State of Delaware. The revision adds a new section, Section 2--Control of Nitrogen Oxide Emissions.../SIP Regulation No. 42-- Specific Emission Control Requirements for controlling nitrogen oxide (NO X...

Wisconsin Maternity Leave and Fringe Benefits: Policies, Practices and Problems.

Science.gov (United States)

Gerner, Jennifer

The study examines the economic implications in Wisconsin of the 1972 Equal Employment Opportunity Commission guideline which requires employers to treat maternity leave as a temporary disability. First, the static cost of the maternity leave guideline to employers is estimated for the State of Wisconsin. Second, some examination of the economic…

Nitrogen loss from anaerobic ammonium oxidation coupled to Iron(III) reduction in a riparian zone.

Science.gov (United States)

Ding, Bangjing; Li, Zhengkui; Qin, Yunbin

2017-12-01

Anaerobic ammonium oxidation coupled to iron(III) reduction (termed Feammox) is a recently discovered pathway of nitrogen cycling. However, little is known about the pathways of N transformation via Feammox process in riparian zones. In this study, evidence for Feammox in riparian zones with or without vegetation cover was demonstrated using isotope tracing technique and high-throughput sequencing technology. The results showed that Feammox could occur in riparian zones, and demonstrated that N 2 directly from Feammox was dominant Feammox pathway. The Feammox rates in vegetated soil samples was 0.32-0.37 mg N kg -1 d -1 , which is higher than that in un-vegetated soil samples (0.20 mg N kg -1 d -1 ). Moreover, the growth of vegetation led to a 4.99-6.41% increase in the abundance of iron reducing bacteria (Anaeromyxobacter, Pseudomonas and Geobacter) and iron reducing bacteria play an essential role in Feammox process. An estimated loss of 23.7-43.9 kg N ha -1 year -1 was associated with Feammox in the examined riparian zone. Overall, the co-occurrence of ammonium oxidation and iron reduction suggest that Feammox can play an essential role in the pathway of nitrogen removal in riparian zones. Copyright © 2017 Elsevier Ltd. All rights reserved.

Simultaneous reduction and nitrogen functionalization of graphene oxide using lemon for metal-free oxygen reduction reaction

Science.gov (United States)

Begum, Halima; Ahmed, Mohammad Shamsuddin; Cho, Sung; Jeon, Seungwon

2017-12-01

Inspire by the vision of finding a simple and green method for simultaneous reduction and nitrogen (N)-functionalization of graphene oxide (GO), a N-rich reduced graphene oxide (rGO) has been synthesized through a facile and ecofriendly hydrothermal strategy while most of the existing methods are involving with multiple steps and highly toxic reducing agents that are harmful to human health and environment. In this paper, the simultaneous reduction and N-functionalization of GO using as available lemon juice (denoted as Lem-rGO) for metal-free electrocatalysis towards oxygen reduction reaction (ORR) is described. The proposed method is based on the reduction of GO using of the reducing and the N-precursor capability of ascorbic acid and citric acid as well as the nitrogenous compounds, respectively, that containing in lemon juice. The resultant Lem-rGO has higher reduction degree, higher specific surface area and better crystalline nature with N-incorporation than that of well investigated ascorbic acid and citric acid treated rGO. As a result, it shows better ORR electrocatalytic activity in respect to the improved onset potential, electron transfer rate and kinetics than those typical rGO catalysts. Moreover, it shows a significant tolerance to the anodic fuels and durability than the Pt/C during ORR.

Ultrasound coupled with Fenton oxidation pre-treatment of sludge to release organic carbon, nitrogen and phosphorus

Energy Technology Data Exchange (ETDEWEB)

Gong, Changxiu [School of Environment, Tsinghua University, Beijing 100084 (China); Jiang, Jianguo, E-mail: jianguoj@mail.tsinghua.edu.cn [School of Environment, Tsinghua University, Beijing 100084 (China); Key Laboratory for Solid Waste Management and Environment Safety, Ministry of Education of China (China); Collaborative Innovation Center for Regional Environmental Quality, Tsinghua University, Beijing (China); Li, De' an [School of Environment, Tsinghua University, Beijing 100084 (China)

2015-11-01

We focused on the effects of ultrasound and Fenton reagent in ultrasonic coupling Fenton oxidation (U + F) pre-treatment processes on the disintegration of wastewater treatment plant sludge. The results demonstrated that U + F treatment could significantly increase soluble COD, TOC, total N, proteins, total P and PO{sub 4}{sup 3−} concentrations in sludge supernatant. This method was more effective than ultrasonic (U) or Fenton oxidation (F) treatment alone. U + F treatment increased the soluble COD by 2.1- and 1.4-fold compared with U and F alone, respectively. U + F treatment increased the total N and P by 1.7- and 2.2-fold, respectively, compared with F alone. After U + F treatment, sludge showed a considerably finer particle size and looser microstructure based on scanning electron microscopy, and the highest OH· signal intensity increased from 568.7 by F treatment to 1106.3 using electron spin resonance. This demonstrated that U + F treatment induces disintegration of sludge and release of organic carbon, nitrogen and phosphorus better. - Highlights: • Combined ultrasound–Fenton pre-treatment was proposed for sludge disintegration. • Ultrasound–Fenton significantly increased carbon, nitrogen and phosphorus release. • Higher level of OH· was detected after combined disintegration than Fenton.

Ultrasound coupled with Fenton oxidation pre-treatment of sludge to release organic carbon, nitrogen and phosphorus

International Nuclear Information System (INIS)

Gong, Changxiu; Jiang, Jianguo; Li, De'an

2015-01-01

We focused on the effects of ultrasound and Fenton reagent in ultrasonic coupling Fenton oxidation (U + F) pre-treatment processes on the disintegration of wastewater treatment plant sludge. The results demonstrated that U + F treatment could significantly increase soluble COD, TOC, total N, proteins, total P and PO 4 3− concentrations in sludge supernatant. This method was more effective than ultrasonic (U) or Fenton oxidation (F) treatment alone. U + F treatment increased the soluble COD by 2.1- and 1.4-fold compared with U and F alone, respectively. U + F treatment increased the total N and P by 1.7- and 2.2-fold, respectively, compared with F alone. After U + F treatment, sludge showed a considerably finer particle size and looser microstructure based on scanning electron microscopy, and the highest OH· signal intensity increased from 568.7 by F treatment to 1106.3 using electron spin resonance. This demonstrated that U + F treatment induces disintegration of sludge and release of organic carbon, nitrogen and phosphorus better. - Highlights: • Combined ultrasound–Fenton pre-treatment was proposed for sludge disintegration. • Ultrasound–Fenton significantly increased carbon, nitrogen and phosphorus release. • Higher level of OH· was detected after combined disintegration than Fenton

[Determination of the daily changes curve of nitrogen oxides in the atmosphere by digital imaging colorimetry method].

Science.gov (United States)

Yang, Chuan-Xiao; Sun, Xiang-Ying; Liu, Bin

2009-06-01

From the digital images of the red complex which resulted in the interaction of nitrite with N-(1-naphthyl) ethylenediamine dihydrochloride and P-Aminobenzene sulfonic acid, it could be seen that the solution colors obviously increased with increasing the concentration of nitrite ion. The JPEG format of the digital images was transformed into gray-scale format by origin 7.0 software, and the gray values were measured with scion image software. It could be seen that the gray values of the digital image obviously increased with increasing the concentration of nitrite ion, too. Thus a novel digital imaging colorimetric (DIC) method to determine nitrogen oxides (NO(x)) contents in air was developed. Based on the red, green and blue (RGB) tricolor theory, the principle of the digital imaging colorimetric method and the influential factors on digital imaging were discussed. The present method was successfully applied to the determination of the daily changes curve of nitrogen oxides in the atmosphere and NO2- in synthetic samples with the recovery of 97.3%-104.0%, and the relative standard deviation (RSD) was less than 5.0%. The results of the determination were consistent with those obtained by spectrophotometric method.

Simulation of Working Processes in the Water-Tube Boiler Furnace with the Purpose of Reducing Emissions of Nitrogen Oxides

Directory of Open Access Journals (Sweden)

Redko A.A.

2017-04-01

Full Text Available A significant number of domestic and industrial boilers are in operation in Ukraine. Nitrogen oxides are the most dangerous among all combustion products that pollute the atmosphere, therefore, one should take some measures for decreasing the formation of nitrogen oxides during combustion. The studies were carried out at the boilers of low power (100 kW with a tubular radiator and an open end. The studies in the furnaces of industrial steam boilers having a tubular radiator with a closed end have not been done. The numerical study results of the gaseous fuel combustion processes in the furnace of a DE-10/14 steam water-tube boiler are presented. The fuel-air mixture is formed by premixing the 15% part of the air with a primary burner twist factor n=2.4 and a secondary burner twist factor n=1.6, and an air excess factor αв=10. As a result of the studies, the temperature and velocity distributions of gases in the combustion chamber, the density of heat flows on the screen tubular surfaces, and the concentrations of the combustion components were determined. Flue gas recirculation in the volume of 80-100% is provided, and the reversible movement of combustion products towards the combustion front provides a reduction in the concentration of nitrogen oxides up to 123-125 mg/m3 at the furnace outlet. Disadvantages are the following: the formation of stagnant zones near the end of the secondary radiator. The optimum diameter of the tubular radiator equals to two burners diameters and tubular radiator is located at a distance of one meter from the burner cutoff.

Fractional exhaled nitric oxide and multiple breath nitrogen washout in preschool healthy and asthmatic children

DEFF Research Database (Denmark)

Vilmann, Lea; Buchvald, Frederik; Green, Kent

2017-01-01

Introduction Objectively assessing pulmonary disease is challenging in preschool children with asthma. We evaluated the feasibility of measuring fractional exhaled nitrogen oxide (FeNO) and multiple breath nitrogen washout (N2MBW) in children. We compared their capacities for discriminating between...... children with asthma and healthy controls. Methods We measured FeNO and N2MBW-derived indices of lung clearance (LCI2.5) and conductive and acinar ventilation heterogeneity (Scond and Sacin) in 65 preschool children; 35 with physician-diagnosed asthma and 30 healthy. FeNO was measured with a portable.......023), but similar FeNO, LCI2.5 and Sacinvalues. Conclusion The feasibility of measuring FeNO was highly age-dependent and not applicable in children under age 4. N2MBW was feasible in the majority of preschool children. Scond, but not FeNO, could discriminate between children with asthma and healthy controls....

Wisconsin's forest resources, 2010

Science.gov (United States)

C.H. Perry

2011-01-01

This publication provides an overview of forest resource attributes for Wisconsin based on an annual inventory conducted by the Forest Inventory and Analysis (FIA) program at the Northern Research Station of the U.S. Forest Service. These estimates, along with web-posted core tables, will be updated annually. For more information please refer to page 4 of this report...

Wisconsin's forest resources, 2005

Science.gov (United States)

Charles, H. (Hobie) Perry; Gary J. Brand

2006-01-01

The annual forest inventory of Wisconsin continues, and this document reports 2001-05 moving averages for most variables and comparisons between 2000 and 2005 for growth, removals, and mortality. Summary resource tables can be generated through the Forest Inventory Mapmaker website at http://ncrs2.fs.fed.us/4801/fiadb/index. htm. Estimates from this inventory show a...

Wisconsin's forest resources, 2006

Science.gov (United States)

C.H. Perry; V.A. Everson

2007-01-01

Figure 2 was revised by the author in August 2008. This publication provides an overview of forest resource attributes for Wisconsin based on an annual inventory conducted by the Forest Inventory and Analysis program at the Northern Research Station of the U.S. Forest Service from 2002-2006. These estimates, along with associated core tables postedon the Internet, are...

Wisconsin's Forest Resources, 2007

Science.gov (United States)

C.H. Perry; V.A. Everson

2008-01-01

This publication provides an overview of forest resource attributes for Wisconsin based on an annual inventory conducted by the Forest Inventory and Analysis (FIA) program of the U.S. Forest Service, Northern Research Station. These estimates, along with web-posted core tables, are updated annually. For more information please refer to page 4 of this report.

Wisconsin's forest resources, 2009

Science.gov (United States)

C.H. Perry

2011-01-01

This publication provides an overview of forest resource attributes for Wisconsin based on an annual inventory conducted by the Forest Inventory and Analysis (FIA) program at the Northern Research Station of the U.S. Forest Service. These estimates, along with web-posted core tables, will be updated annually. For more information, please refer to page 4 of this report...

The Pkn22 Ser/Thr kinase in Nostoc PCC 7120: role of FurA and NtcA regulators and transcript profiling under nitrogen starvation and oxidative stress.

Science.gov (United States)

Yingping, Fan; Lemeille, Sylvain; González, Andrés; Risoul, Véronique; Denis, Yann; Richaud, Pierre; Lamrabet, Otmane; Fillat, Maria F; Zhang, Cheng-Cai; Latifi, Amel

2015-07-29

The filamentous cyanobacterium Nostoc sp. strain PCC 7120 can fix N2 when combined nitrogen is not available. Furthermore, it has to cope with reactive oxygen species generated as byproducts of photosynthesis and respiration. We have previously demonstrated the synthesis of Ser/Thr kinase Pkn22 as an important survival response of Nostoc to oxidative damage. In this study we wished to investigate the possible involvement of this kinase in signalling peroxide stress and nitrogen deprivation. Quantitative RT-PCR experiments revealed that the pkn22 gene is induced in response to peroxide stress and to combined nitrogen starvation. Electrophoretic motility assays indicated that the pkn22 promoter is recognized by the global transcriptional regulators FurA and NtcA. Transcriptomic analysis comparing a pkn22-insertion mutant and the wild type strain indicated that this kinase regulates genes involved in important cellular functions such as photosynthesis, carbon metabolism and iron acquisition. Since metabolic changes may lead to oxidative stress, we investigated whether this is the case with nitrogen starvation. Our results rather invalidate this hypothesis thereby suggesting that the function of Pkn22 under nitrogen starvation is independent of its role in response to peroxide stress. Our analyses have permitted a more complete functional description of Ser/Thr kinase in Nostoc. We have decrypted the transcriptional regulation of the pkn22 gene, and analysed the whole set of genes under the control of this kinase in response to the two environmental changes often encountered by cyanobacteria in their natural habitat: oxidative stress and nitrogen deprivation.

Forest fuel reduces the nitrogen load - calculations of nitrogen flows

International Nuclear Information System (INIS)

Burstroem, F.; Johansson, Jan.

1995-12-01

Nitrogen deposition in Sweden has increased strongly during recent decades, particularly in southern Sweden. Nitrogen appears to be largely accumulated in biomass and in the soil. It is therefore desirable to check the accumulation of nitrogen in the forest. The most suitable way of doing this is to remove more nitrogen-rich biomass from the forest, i.e., increase the removal of felling residues from final fellings and cleanings. An ecological condition for intensive removal of fuel is that the ashes are returned. The critical load for nitrogen, CL(N), indicates the level of nitrogen deposition that the forest can withstand without leading to ecological changes. Today, nitrogen deposition is higher than the CL(N) in almost all of Sweden. CL(N) is calculated in such a manner that nitrogen deposition should largely be balanced by nitrogen losses through harvesting during a forest rotation. The value of CL(N) thus largely depends on how much nitrogen is removed with the harvested biomass. When both stems and felling residues are harvested, the CL(N) is about three times higher than in conventional forestry. The increase is directly related to the amount of nitrogen in the removed biofuel. Use of biofuel also causes a certain amount of nitrogen emissions. From the environmental viewpoint there is no difference between the sources of the nitrogen compounds. An analysis of the entire fuel chain shows that, compared with the amount of nitrogen removed from the forest with the fuel, about 5 % will be emitted as nitrogen oxides or ammonia during combustion, and a further ca 5 % during handling and transports. A net amount of about 90 % of biomass nitrogen is removed from the system and becomes inert nitrogen (N 2 ). 60 refs, 3 figs, 4 tabs, 11 appendices

N2 Dissociation In The Mesosphere Due To Secondary Electrons During A Solar Proton Event: The Effect On Atomic Nitrogen and Nitric Oxide

Science.gov (United States)

Verronen, P. T.; Shematovich, V. I.; Bisikalo, D. V.; Turunen, E.; Ulich, Th.

Solar proton events have an effect on the middle atmospheric odd nitrogen chem- istry. During a solar proton event high energy protons enter Earth's middle atmosphere where they ionize ambient gas. Ionization leads to production of atomic nitrogen, and further to production of nitric oxide, through ion chemistry. In addition, ionization processes produce secondary electrons that, if possessing 9.76 eV or more energy, dissociate N2 providing an additional source of atomic nitrogen. We have calculated mesospheric N2 dissociation rate due to secondary electrons dur- ing a solar proton event. Further, we have studied the effect on atomic nitrogen and nitric oxide at altitudes between 50 and 90 km. It was found that N2 is efficiently dis- sociated in the lower mesosphere by secondary electrons, with rates up to 103 cm-3 s-1 at 50 km. Thus, secondary electrons significantly add to odd nitrogen produc- tion. As a result of N2 dissociation, atomic nitrogen is greatly enhanced in both N(4S) and N(2D) states by 259% and 1220% maximum increases at 50 km, respectively. This further leads to a maximum increase of 16.5% in NO concentration at 61 km via chemical reactions. In our study a Monte Carlo model was used to calculate the total ionization rate and secondary electrons flux due to precipitating protons. These where then used as input to a detailed ion and neutral chemistry model and a steady-state solution was calcu- lated for two cases: With and without N2 dissociation due to secondary electrons.

General Solvent-dependent Strategy toward Enhanced Oxygen Reduction Reaction in Graphene/Metal Oxide Nanohybrids: Effects of Nitrogen-containing Solvent

Science.gov (United States)

Kao, Wei-Yao; Chen, Wei-Quan; Chiu, Yu-Hsiang; Ho, Yu-Hsuan; Chen, Chun-Hu

2016-11-01

A general solvent-dependent protocol directly influencing the oxygen reduction reaction (ORR) in metal oxide/graphene nanohybrids has been demonstrated. We conducted the two-step synthesis of cobalt oxide/N-doped graphene nanohybrids (CNG) with solvents of water, ethanol, and dimethylformamide (DMF), representing tree typical categories of aqueous, polar organic, and organic N-containing solvents commonly adopted for graphene nanocomposites preparation. The superior ORR performance of the DMF-hybrids can be attributed to the high nitrogen-doping, aggregation-free hybridization, and unique graphene porous structures. As DMF is the more effective N-source, the spectroscopic results support a catalytic nitrogenation potentially mediated by cobalt-DMF coordination complexes. The wide-distribution of porosity (covering micro-, meso-, to macro-pore) and micron-void assembly of graphene may further enhance the diffusion kinetics for ORR. As the results, CNG by DMF-synthesis exhibits the high ORR activities close to Pt/C (i.e. only 8 mV difference of half-wave potential with electron transfer number of 3.96) with the better durability in the alkaline condition. Additional graphene hybrids comprised of iron and manganese oxides also show the superior ORR activities by DMF-synthesis, confirming the general solvent-dependent protocol to achieve enhanced ORR activities.

Investigations of Nitrogen Oxide Plasmas: Fundamental Chemistry and Surface Reactivity and Monitoring Student Perceptions in a General Chemistry Recitation

Science.gov (United States)

Blechle, Joshua M.

2016-01-01

Part I of this dissertation focuses on investigations of nitrogen oxide plasma systems. With increasing concerns over the environmental presence of NxOy species, there is growing interest in utilizing plasma-assisted conversion techniques. Advances, however, have been limited because of the lack of knowledge regarding the fundamental chemistry of…

40 CFR 81.30 - Southeastern Wisconsin Intrastate Air Quality Control Region.

Science.gov (United States)

2010-07-01

... Quality Control Region. 81.30 Section 81.30 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Air Quality Control Regions § 81.30 Southeastern Wisconsin Intrastate Air Quality Control Region. The Metropolitan Milwaukee Intrastate Air Quality Control Region (Wisconsin) has been renamed the Southeastern...

Potential coupling effects of ammonia-oxidizing and anaerobic ammonium-oxidizing bacteria on completely autotrophic nitrogen removal over nitrite biofilm formation induced by the second messenger cyclic diguanylate.

Science.gov (United States)

Wang, Chao; Liu, Sitong; Xu, Xiaochen; Zhao, Chuanqi; Yang, Fenglin; Wang, Dong

2017-05-01

The objective of this study was to investigate the influence of extracellular polymeric substance (EPS) on the coupling effects between ammonia-oxidizing bacteria (AOB) and anaerobic ammonium-oxidizing (anammox) bacteria for the completely autotrophic nitrogen removal over nitrite (CANON) biofilm formation in a moving bed biofilm reactor (MBBR). Analysis of the quantity of EPS and cyclic diguanylate (c-di-GMP) confirmed that the contents of polysaccharides and c-di-GMP were correlated in the AOB sludge, anammox sludge, and CANON biofilm. The anammox sludge secreted more EPS (especially polysaccharides) than AOB with a markedly higher c-di-GMP content, which could be used by the bacteria to regulate the synthesis of exopolysaccharides that are ultimately used as a fixation matrix, for the adhesion of biomass. Indeed, increased intracellular c-di-GMP concentrations in the anammox sludge enhanced the regulation of polysaccharides to promote the adhesion of AOB and formation of the CANON biofilm. Overall, the results of this study provide new comprehensive information regarding the coupling effects of AOB and anammox bacteria for the nitrogen removal process.

Amorphous Oxide Thin Film Transistors with Nitrogen-Doped Hetero-Structure Channel Layers

Directory of Open Access Journals (Sweden)

Haiting Xie

2017-10-01

Full Text Available The nitrogen-doped amorphous oxide semiconductor (AOS thinfilm transistors (TFTs with double-stacked channel layers (DSCL were prepared and characterized. The DSCL structure was composed of nitrogen-doped amorphous InGaZnO and InZnO films (a-IGZO:N/a-IZO:N or a-IZO:N/a-IGZO:N and gave the corresponding TFT devices large field-effect mobility due to the presence of double conduction channels. The a-IZO:N/a-IGZO:N TFTs, in particular, showed even better electrical performance (µFE = 15.0 cm2・V−1・s−1, SS = 0.5 V/dec, VTH = 1.5 V, ION/IOFF = 1.1 × 108 and stability (VTH shift of 1.5, −0.5 and −2.5 V for positive bias-stress, negative bias-stress, and thermal stress tests, respectively than the a-IGZO:N/a-IZO:N TFTs. Based on the X-ray photoemission spectroscopy measurements and energy band analysis, we assumed that the optimized interface trap states, the less ambient gas adsorption, and the better suppression of oxygen vacancies in the a-IZO:N/a-IGZO:N hetero-structures might explain the better behavior of the corresponding TFTs.

Multi-layered zinc oxide-graphene composite thin films for selective nitrogen dioxide sensing

Science.gov (United States)

Ghosh, A.; Bhowmick, T.; Majumder, S. B.

2018-02-01

In the present work, selective nitrogen dioxide (NO2) sensing characteristics of multi-layered graphene-zinc oxide (G-ZnO) thin films have been demonstrated at 150 °C. The response% of 5 ppm NO2 was measured to be 894% with response and recovery times estimated to be 150 s and 315 s, respectively. In these composite films, the interaction between graphene and zinc oxide is established through X-ray photoelectron spectroscopy in conjunction with the analyses of photoluminescence spectra. Superior NO2 sensing of these films is due to simultaneous chemiadsorption of molecular oxygen and NO2 gases onto graphene and ZnO surfaces, resulting in an appreciable increase in the depletion layer width and thereby the sensor resistance. The sensor responses for other reducing gases (viz., CO, H2, and i-C4H10) are postulated to be due to their catalytic oxidation on the sensor surface, resulting in a decrease in the sensor resistance upon gas exposure. At lower operating temperature, due to the molecular nature of the chemiadsorbed oxygen, poor catalytic oxidation leads to a far lower sensor response for reducing gases as compared to NO2. For mixed NO2 and reducing gas sensing, we have reported that fast Fourier transformation of the resistance transients of all these gases in conjunction with principal component analyses forms a reasonably distinct cluster and, therefore, could easily be differentiated.

40 CFR 52.1876 - Control strategy: Nitrogen dioxide.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Control strategy: Nitrogen dioxide. 52.1876 Section 52.1876 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS...: Nitrogen dioxide. (a) The condition to EPA's approval of the oxides of nitrogen State Implementation Plan...

Nitrogen compounds behavior under irradiation environment

International Nuclear Information System (INIS)

Ichikawa, Nagayoshi; Takagi, Junichi; Yotsuyanagi, Tadasu

1991-01-01

Laboratory experiments were performed to evaluate nitrogen compounds behavior in liquid phase under irradiation environments. Nitrogen compounds take a chemical form of ammonium ion under reducing condition by gamma irradiation, whereas ammonium ions are rather stable even under oxidizing conditions. Key reactions were pointed out and their reaction rate constants and activation energies were estimated through computer code simulation. A reaction scheme for nitrogen compounds including protonate reaction was proposed. (author)

Substantial nitrogen pollution embedded in international trade

Science.gov (United States)

Oita, Azusa; Malik, Arunima; Kanemoto, Keiichiro; Geschke, Arne; Nishijima, Shota; Lenzen, Manfred

2016-02-01

Anthropogenic emissions of reactive nitrogen to the atmosphere and water bodies can damage human health and ecosystems. As a measure of a nation’s contribution to this potential damage, a country’s nitrogen footprint has been defined as the quantity of reactive nitrogen emitted during the production, consumption and transportation of commodities consumed within that country, whether those commodities are produced domestically or internationally. Here we use global emissions databases, a global nitrogen cycle model, and a global input-output database of domestic and international trade to calculate the nitrogen footprints for 188 countries as the sum of emissions of ammonia, nitrogen oxides and nitrous oxide to the atmosphere, and of nitrogen potentially exportable to water bodies. Per-capita footprints range from under 7 kg N yr-1 in some developing countries to over 100 kg N yr-1 in some wealthy nations. Consumption in China, India, the United States and Brazil is responsible for 46% of global emissions. Roughly a quarter of the global nitrogen footprint is from commodities that were traded across country borders. The main net exporters have significant agricultural, food and textile exports, and are often developing countries, whereas important net importers are almost exclusively developed economies. We conclude that substantial local nitrogen pollution is driven by demand from consumers in other countries.

Anaerobic sulfide-oxidation in marine colorless sulfur-oxidizing bacteria

Digital Repository Service at National Institute of Oceanography (India)

LokaBharathi, P.A.; Nair, S.; Chandramohan, D.

Colorless sulfur-oxidizing bacteria are ubiquitous in Indian waters and have the ability to oxidize sulfide under anaerobic conditions. These bacteria can not only mediate the sulfur cycle oxidatively but also the nitrogen cycle reductively without...

Attenuation of acute nitrogen mustard-induced lung injury, inflammation and fibrogenesis by a nitric oxide synthase inhibitor

Energy Technology Data Exchange (ETDEWEB)

Malaviya, Rama; Venosa, Alessandro [Department of Pharmacology and Toxicology, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, NJ 08854 (United States); Hall, LeRoy [Drug Safety Sciences, Johnson and Johnson, Raritan, NJ 08869 (United States); Gow, Andrew J. [Department of Pharmacology and Toxicology, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, NJ 08854 (United States); Sinko, Patrick J. [Department of Pharmaceutics, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, NJ 08854 (United States); Laskin, Jeffrey D. [Department of Environmental and Occupational Medicine, UMDNJ-Robert Wood Johnson Medical School, Piscataway, NJ 08854 (United States); Laskin, Debra L., E-mail: laskin@eohsi.rutgers.edu [Department of Pharmacology and Toxicology, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, NJ 08854 (United States)

2012-12-15

Nitrogen mustard (NM) is a toxic vesicant known to cause damage to the respiratory tract. Injury is associated with increased expression of inducible nitric oxide synthase (iNOS). In these studies we analyzed the effects of transient inhibition of iNOS using aminoguanidine (AG) on NM-induced pulmonary toxicity. Rats were treated intratracheally with 0.125 mg/kg NM or control. Bronchoalveolar lavage fluid (BAL) and lung tissue were collected 1 d–28 d later and lung injury, oxidative stress and fibrosis assessed. NM exposure resulted in progressive histopathological changes in the lung including multifocal lesions, perivascular and peribronchial edema, inflammatory cell accumulation, alveolar fibrin deposition, bronchiolization of alveolar septal walls, and fibrosis. This was correlated with trichrome staining and expression of proliferating cell nuclear antigen (PCNA). Expression of heme oxygenase (HO)-1 and manganese superoxide dismutase (Mn-SOD) was also increased in the lung following NM exposure, along with levels of protein and inflammatory cells in BAL, consistent with oxidative stress and alveolar-epithelial injury. Both classically activated proinflammatory (iNOS{sup +} and cyclooxygenase-2{sup +}) and alternatively activated profibrotic (YM-1{sup +} and galectin-3{sup +}) macrophages appeared in the lung following NM administration; this was evident within 1 d, and persisted for 28 d. AG administration (50 mg/kg, 2 ×/day, 1 d–3 d) abrogated NM-induced injury, oxidative stress and inflammation at 1 d and 3 d post exposure, with no effects at 7 d or 28 d. These findings indicate that nitric oxide generated via iNOS contributes to acute NM-induced lung toxicity, however, transient inhibition of iNOS is not sufficient to protect against pulmonary fibrosis. -- Highlights: ► Nitrogen mustard (NM) induces acute lung injury and fibrosis. ► Pulmonary toxicity is associated with increased expression of iNOS. ► Transient inhibition of iNOS attenuates acute

Thermal and combined thermal and radiolytic reactions involving nitrous oxide, hydrogen, nitrogen, and ammonia in contact with tank 241-SY-101 simulated waste

International Nuclear Information System (INIS)

Bryan, S.A.; Pederson, L.R.

1996-02-01

Work described in this report was conducted at Pacific Northwest National Laboratory (PNNL) for the Flammable Gas Safety Project, the purpose of which is to develop information needed to support Westinghouse Hanford Company (WHC) in their efforts to ensure the safe interim storage of wastes at the Hanford Site. Described in this report are the results of tests to evaluate the rates of thermal and combined thermal and radiolytic reactions involving flammable gases in the presence of Tank 241-SY-101 simulated waste. Flammable gases generated by the radiolysis of water and by the thermal and radiolytic decomposition of organic waste constituents may themselves participate in further reactions. Examples include the decomposition of nitrous oxide to yield nitrogen and oxygen, the reaction of nitrous oxide and hydrogen to produce nitrogen and water, and the reaction of nitrogen and hydrogen to produce ammonia. The composition of the gases trapped in bubbles in the wastes might therefore change continuously as a function of the time that the gas bubbles are retained

Of Needles and Haystacks: Building an Accurate Statewide Dropout Early Warning System in Wisconsin

Science.gov (United States)

Knowles, Jared E.

2015-01-01

The state of Wisconsin has one of the highest four year graduation rates in the nation, but deep disparities among student subgroups remain. To address this the state has created the Wisconsin Dropout Early Warning System (DEWS), a predictive model of student dropout risk for students in grades six through nine. The Wisconsin DEWS is in use…

Removal of organic substances and oxidation of ammonium nitrogen by a down-flow hanging sponge (DHS) reactor under high salinity conditions.

Science.gov (United States)

Uemura, Shigeki; Suzuki, Saori; Abe, Kenichi; Kubota, Keiichi; Yamaguchi, Takashi; Ohashi, Akiyoshi; Takemura, Yasuyuki; Harada, Hideki

2010-07-01

A down-flow hanging sponge (DHS) reactor, constructed by connecting three identical treatment units in series, was fed with highly saline artificial coke-plant wastewater containing 1400 mg L(-1) of phenol in terms of chemical oxygen demand (COD) and 500 mg-NL(-1) of ammonium nitrogen. The COD was removed by the 1st unit, achieving 92% removal at an average COD loading rate of 3.0 kg-COD m(-3)d(-1) for all units, with oxidation of ammonium nitrogen occurring primarily in the two downstream units. Microbial assays of the different units of the reactor revealed greater numbers of nitrifying bacteria in the 2nd and 3rd units than in the 1st unit, corresponding with the observed ammonium oxidation pattern of the reactor. These findings suggest that a succession of microflora was successfully established along the DHS. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Development of anaerobic ammonium oxidation (anammox) for biological nitrogen removal in domestic wastewater treatment (Case study: Surabaya City, Indonesia)

Science.gov (United States)

Wijaya, I. Made Wahyu; Soedjono, Eddy Setiadi; Fitriani, Nurina

2017-11-01

Domestic wastewater effluent is the main contributor to diverse water pollution problems. The contaminants contained in the wastewater lead the low quality of water. The presence of ammonium and nitrate along with phosphorus are potentially cause eutrophication and endanger aquatic life. Excess nutrients, mostly N and P is the main cause of eutrophication which is result in oxygen depletion, biodiversity reduction, fish kills, odor and increased toxicity. Most of the domestic wastewater in Surabaya City still contains nitrogen that exceeded the threshold. The range of ammonium and orthophosphate concentration in the domestic wastewater is between 6.29 mg/L - 38.91 mg/L and 0.44 mg/L - 1.86 mg/L, respectively. An advance biological nitrogen removal process called anammox is a sustainable and cost effective alternative to the basic method of nitrogen removal, such as nitrification and denitrification. Many research have been conducted through anammox and resulted promisingly way to remove nitrogen. In this process, ammonium will be oxidized with nitrite as an electron acceptor to produce nitrogen gas and low nitrate in anoxic condition. Anammox requires less oxygen demand, no needs external carbon source, and low operational cost. Based on its advantages, anammox is possible to apply in domestic wastewater treatment in Surabaya with many further studies.

Lipids as paleomarkers to constrain the marine nitrogen cycle

NARCIS (Netherlands)

Rush, Darci; Sinninghe Damsté, Jaap S

Global climate is, in part, regulated by the effect of microbial processes on biogeochemical cycling. The nitrogen cycle, in particular, is driven by microorganisms responsible for the fixation and loss of nitrogen, and the reduction-oxidation transformations of bio-available nitrogen. Within marine

Lipids as paleomarkers to constrain the marine nitrogen cycle

NARCIS (Netherlands)

Rush, D.; Sinninghe Damsté, J.S.

2017-01-01

Global climate is, in part, regulated by the effect of microbial processes on biogeochemical cycling. The nitrogen cycle, in particular, is driven by microorganisms responsible for the fixation and loss of nitrogen, and the reduction-oxidation transformations of bio-available nitrogen. Within marine

Nitrapyrin addition mitigates nitrous oxide emissions and raises nitrogen use efficiency in plastic-film-mulched drip-fertigated cotton field.

Science.gov (United States)

Liu, Tao; Liang, Yongchao; Chu, Guixin

2017-01-01

Nitrification inhibitors (NIs) have been used extensively to reduce nitrogen losses and increase crop nitrogen nutrition. However, information is still scant regarding the influence of NIs on nitrogen transformation, nitrous oxide (N2O) emission and nitrogen utilization in plastic-film-mulched calcareous soil under high frequency drip-fertigated condition. Therefore, a field trial was conducted to evaluate the effect of nitrapyrin (2-chloro-6-(trichloromethyl)-pyridine) on soil mineral nitrogen (N) transformation, N2O emission and nitrogen use efficiency (NUE) in a drip-fertigated cotton-growing calcareous field. Three treatments were established: control (no N fertilizer), urea (225 kg N ha-1) and urea+nitrapyrin (225 kg N ha-1+2.25 kg nitrapyrin ha-1). Compared with urea alone, urea plus nitrapyrin decreased the average N2O emission fluxes by 6.6-21.8% in June, July and August significantly in a drip-fertigation cycle. Urea application increased the seasonal cumulative N2O emission by 2.4 kg N ha-1 compared with control, and nitrapyrin addition significantly mitigated the seasonal N2O emission by 14.3% compared with urea only. During the main growing season, the average soil ammonium nitrogen (NH4+-N) concentration was 28.0% greater and soil nitrate nitrogen (NO3--N) concentration was 13.8% less in the urea+nitrapyrin treatment than in the urea treatment. Soil NO3--N and water-filled pore space (WFPS) were more closely correlated than soil NH4+-N with soil N2O fluxes under drip-fertigated condition (Puse efficiency by 10.7%. The results demonstrated that nitrapyrin addition significantly inhibited soil nitrification and maintained more NH4+-N in soil, mitigated N2O losses and improved nitrogen use efficiency in plastic-film-mulched calcareous soil under high frequency drip-fertigated condition.

Methane oxidation in soil profiles of Dutch and Finnish coniferous forests with different soil texture and atmospheric nitrogen deposition

NARCIS (Netherlands)

Saari, A.; Martikainen, P.J.; Ferm, A.; Ruuskanen, J.; De Boer, W.; Troelstra, S.R.; Laanbroek, H.J.

1997-01-01

We studied methane oxidation capacity in soil profiles of Dutch and Finnish coniferous forests. The Finnish sites (n = 9) had nitrogen depositions from 3 to 36 kg N ha(-1) a(-1). The deposition of N on the Dutch sites (n = 13) was higher ranging from 50 to 92 kg N ha(-1) a(-1). The Dutch sites had

Assessment of high penetration of solar photovoltaics in Wisconsin

International Nuclear Information System (INIS)

Myers, Kevin S.; Klein, Sanford A.; Reindl, Douglas T.

2010-01-01

This paper provides an assessment of the large-scale implementation of distributed solar photovoltaics in Wisconsin with regard to its interaction with the utility grid, economics of varying levels of high penetration, and displaced emissions. These assessment factors are quantified using simulations with measured hourly solar radiation and weather data from the National Solar Radiation Database as primary inputs. Hourly utility load data for each electric utility in Wisconsin for a complete year were used in combination with the simulated PV output to quantify the impacts of high penetration of distributed PV on the aggregate Wisconsin electric utility load. As the penetration rate of distributed PV systems increases, both economic and environmental benefits experience diminishing returns. At penetration rates exceeding 15-20% of the aggregate utility load peak, less of the PV-energy is utilized and the contribution of the aggregate electricity generated from PV approaches a practical limit. The limit is not affected by costs, but rather by the time-distribution of available solar radiation and mismatch with the coincidence of aggregate utility electrical loads. The unsubsidized levelized cost of electricity from PV is more than four times greater than the current market price for electricity, based on time-of-use rates, in Wisconsin. At the present time, the investment in solar PV as a cost-effective means to reduce emissions from traditional electricity generation sources is not justified. (author)

The Wisconsin experience with incentives for demand-side management

International Nuclear Information System (INIS)

Landgren, D.A.

1990-01-01

It has been noted that, within traditional regulatory frameworks for electric utilities, factors exist which discourage demand side management (DSM) and that there is a lack of positive incentives for DSM. Regulatory agencies should therefore make it possible for DSM measures to benefit from the same treatment as supply-side measures. The Wisconsin Public Service Commission (WPSC) has recognized this need and has adopted various measures accordingly. The need for efficiency incentives is described according to the particular experience of Wisconsin Electric concerning their recourse to a DSM incentive and according to new incentive models being tested in collaboration with other electricity suppliers in Wisconsin. The WPSC has concluded that the fact of considering the costs relating to DSM as expenses or capitalizing them within the rate base does not motivate the utility to promote DSM programs. The WPSC has thus decided to experiment with energy efficiency incentives in order to evaluate their eventual impact. The choice of the type of incentive had an objective of starting the process in an area where the lack of experience has created, from the regulatory point of view, a reticence on the part of utilities to engage in DSM programs. The WPSC has designed a variety of incentive models which have been adapted to each utility's own situation. Specific incentive programs developed for three Wisconsin utilities are reviewed

Wisconsin Earth and Space Science Education

Science.gov (United States)

Bilbrough, Larry (Technical Monitor); French, George

2003-01-01

The Wisconsin Earth and Space Science Education project successfilly met its objectives of creating a comprehensive online portfolio of science education curricular resources and providing a professional development program to increase educator competency with Earth and Space science content and teaching pedagogy. Overall, 97% of participants stated that their experience was either good or excellent. The favorable response of participant reactions to the professional development opportunities highlights the high quality of the professional development opportunity. The enthusiasm generated for using the curricular material in classroom settings was overwhelmingly positive at 92%. This enthusiasm carried over into actual classroom implementation of resources from the curricular portfolio, with 90% using the resources between 1-6 times during the school year. The project has had a positive impact on student learning in Wisconsin. Although direct measurement of student performance is not possible in a project of this kind, nearly 75% of participating teachers stated that they saw an increase in student performance in math and science as a result of using project resources. Additionally, nearly 75% of participants saw an increase in the enthusiasm of students towards math and science. Finally, some evidence exists that the professional development academies and curricular portfolio have been effective in changing educator behavior. More than half of all participants indicated that they have used more hands-on activities as a result of the Wisconsin Earth and Space Science Education project.

Niche differentiation in nitrogen metabolism among methanotrophs within an operational taxonomic unit.

Science.gov (United States)

Hoefman, Sven; van der Ha, David; Boon, Nico; Vandamme, Peter; De Vos, Paul; Heylen, Kim

2014-04-04

The currently accepted thesis on nitrogenous fertilizer additions on methane oxidation activity assumes niche partitioning among methanotrophic species, with activity responses to changes in nitrogen content being dependent on the in situ methanotrophic community structure Unfortunately, widely applied tools for microbial community assessment only have a limited phylogenetic resolution mostly restricted to genus level diversity, and not to species level as often mistakenly assumed. As a consequence, intragenus or intraspecies metabolic versatility in nitrogen metabolism was never evaluated nor considered among methanotrophic bacteria as a source of differential responses of methane oxidation to nitrogen amendments. We demonstrated that fourteen genotypically different Methylomonas strains, thus distinct below the level at which most techniques assign operational taxonomic units (OTU), show a versatile physiology in their nitrogen metabolism. Differential responses, even among strains with identical 16S rRNA or pmoA gene sequences, were observed for production of nitrite and nitrous oxide from nitrate or ammonium, nitrogen fixation and tolerance to high levels of ammonium, nitrate, and hydroxylamine. Overall, reduction of nitrate to nitrite, nitrogen fixation, higher tolerance to ammonium than nitrate and tolerance and assimilation of nitrite were general features. Differential responses among closely related methanotrophic strains to overcome inhibition and toxicity from high nitrogen loads and assimilation of various nitrogen sources yield competitive fitness advantages to individual methane-oxidizing bacteria. Our observations proved that community structure at the deepest phylogenetic resolution potentially influences in situ functioning.

Predicting Scour of Bedrock in Wisconsin

Science.gov (United States)

2017-04-01

This research evaluates the scour potential of rocks supporting Wisconsin DOT bridge foundations. Ten highway bridges were selected for this study, of which seven are supported by shallow foundations, and five were built on sandstone in rivers/stream...

Oxidative stress protection by newly synthesized nitrogen compounds with pharmacological potential.

Science.gov (United States)

Silva, João P; Areias, Filipe M; Proença, Fernanda M; Coutinho, Olga P

2006-02-09

In this study we used new nitrogen compounds obtained by organic synthesis whose structure predicted an antioxidant potential and then an eventual development as molecules of pharmacological interest in diseases involving oxidative stress. The compounds, identified as FMA4, FMA5, FMA7 and FMA8 differ in the presence of hydroxyl groups located in the C-3 and/or C-4 position of a phenolic unit, which is possibly responsible for their free radicals' buffering capacity. Data from the DPPH discoloration method confirm the high antiradical efficiency of the compounds. The results obtained with cellular models (L929 and PC12) show that they are not toxic and really protect from membrane lipid peroxidation induced by the ascorbate-iron oxidant pair. The level of protection correlates with the drug's lipophilic profile and is sometimes superior to trolox and equivalent to that observed for alpha-tocopherol. The compounds FMA4 and FMA7 present also a high protection from cell death evaluated in the presence of a staurosporine apoptotic stimulus. That protection results in a significant reduction of caspase-3 activity induced by staurosporine which by its turn seems to result from a protection observed in the membrane receptor pathway (caspase-8) together with a protection observed in the mitochondrial pathway (caspase-9). Taken together the results obtained with the new compounds, with linear chains, open up perspectives for their use as therapeutical agents, namely as antioxidants and protectors of apoptotic pathways. On the other hand the slight pro-oxidant profile obtained with the cyclic structures suggests a different therapeutic potential that is under current investigation.

Retention of sulfur and nitrogen oxides from the exhaust gases by radiolysis, a modern method of environmental protection

International Nuclear Information System (INIS)

Macarie, Rodica; Zissulescu, Ecaterina; Martin, Diana; Radoiu, Marilena

2000-01-01

Industry, especially the power industry, is a great generator of gaseous pollutants (SO x , NO x , CO 2 , CO). The oxides are responsible for the 'acid rains' which have a great negative impact on the environment, human beings and animals, while CO 2 emissions contribute to the increase of the greenhouse effect. Retention of the sulfur and nitrogen oxides from the exhaust gases can be carried out either by conventional methods (using chemical adsorbents) or by non-conventional ones (radiolysis). Recently, non-conventional methods have bee given priority, including exhaust gas irradiation with an accelerated electron beam as a more efficient alternative to the gas desulfurization. In order to increase the efficiency of the accelerated electron beam injected into the exhaust gas, the effect of microwave utilization has been investigated. The company S.C. ICPET S.A.-Bucuresti, in cooperation with INFLPR-Bucuresti, investigated the retention by radiolysis of the sulfur and nitrogen oxides from a synthetic mixture of exhaust gases in an installation developed in the laboratory by means of accelerated electron beams, microwaves and by the accelerated electron beams and microwave combined. The paper presents the results obtained in the laboratory experiments and the advantages of radiolysis in comparison with the chemical conventional methods, namely: simultaneous removal of SO 2 and NO x , solid by-products that can be used as fertilizers in agriculture, simple technologies that do not imply catalysts or adsorbents, no waste waters. (authors)

Influence of the technique for injection of flue gas and the configuration of the swirl burner throat on combustion of gaseous fuel and formation of nitrogen oxides in the flame

Science.gov (United States)

Dvoinishnikov, V. A.; Khokhlov, D. A.; Knyaz'kov, V. P.; Ershov, A. Yu.

2017-05-01

How the points at which the flue gas was injected into the swirl burner and the design of the burner outlet influence the formation and development of the flame in the submerged space, as well as the formation of nitrogen oxides in the combustion products, have been studied. The object under numerical investigation is the flame of the GMVI combined (oil/gas) burner swirl burner fitted with a convergent, biconical, cylindrical, or divergent throat at the burner outlet with individual supply of the air and injection of the gaseous fuel through tubing. The burners of two designs were investigated; they differ by the absence or presence of an inlet for individual injection of the flue gas. A technique for numerical simulation of the flame based on the CFD methods widely used in research of this kind underlies the study. Based on the summarized results of the numerical simulation of the processes that occur in jet flows, the specific features of the aerodynamic pattern of the flame have been established. It is shown that the flame can be conventionally divided into several sections over its length in all investigations. The lengths of each of the sections, as well as the form of the fields of axial velocity, temperatures, concentrations of the fuel, oxygen, and carbon and nitrogen oxides, are different and determined by the design features of the burner, the flow rates of the agent, and the compositions of the latter in the burner ducts as well as the configuration of the burner throat and the temperature of the environment. To what degree the burner throat configuration and the techniques for injection of the flue gas at different ambient temperatures influence the formation of nitrogen oxides has been established. It is shown that the supply of the recirculation of flue gas into the fuel injection zone enables a considerable reduction in the formation of nitrogen oxides in the flame combustion products. It has been established that the locations of the zones of

Zinc oxide nanoparticles affect carbon and nitrogen mineralization of Phoenix dactylifera leaf litter in a sandy soil.

Science.gov (United States)

Rashid, Muhammad Imtiaz; Shahzad, Tanvir; Shahid, Muhammad; Ismail, Iqbal M I; Shah, Ghulam Mustafa; Almeelbi, Talal

2017-02-15

We investigated the impact of zinc oxide nanoparticles (ZnO NPs; 1000mgkg -1 soil) on soil microbes and their associated soil functions such as date palm (Phoenix dactylifera) leaf litter (5gkg -1 soil) carbon and nitrogen mineralization in mesocosms containing sandy soil. Nanoparticles application in litter-amended soil significantly decreased the cultivable heterotrophic bacterial and fungal colony forming units (cfu) compared to only litter-amended soil. The decrease in cfu could be related to lower microbial biomass carbon in nanoparticles-litter amended soil. Likewise, ZnO NPs also reduced CO 2 emission by 10% in aforementioned treatment but this was higher than control (soil only). Labile Zn was only detected in the microbial biomass of nanoparticles-litter applied soil indicating that microorganisms consumed this element from freely available nutrients in the soil. In this treatment, dissolved organic carbon and mineral nitrogen were 25 and 34% lower respectively compared to litter-amended soil. Such toxic effects of nanoparticles on litter decomposition resulted in 130 and 122% lower carbon and nitrogen mineralization efficiency respectively. Hence, our results entail that ZnO NPs are toxic to soil microbes and affect their function i.e., carbon and nitrogen mineralization of applied litter thus confirming their toxicity to microbial associated soil functions. Copyright © 2016 Elsevier B.V. All rights reserved.

Creating a perfect storm to increase consumer demand for Wisconsin's Tobacco Quitline.

Science.gov (United States)

Sheffer, Megan A; Redmond, Lezli A; Kobinsky, Kate H; Keller, Paula A; McAfee, Tim; Fiore, Michael C

2010-03-01

Telephone quitlines are a clinically proven and cost-effective population-wide tobacco-dependence treatment, and this option is now available in all 50 states. Yet, only 1% of the smoking population accesses these services annually. This report describes a series of policy, programmatic, and communication initiatives recently implemented in Wisconsin that resulted in a dramatic increase in consumer demand for the Wisconsin Tobacco Quitline (WTQL). In 2007, the Wisconsin legislature voted to increase the state cigarette excise tax rate by $1.00, from $0.77/pack to $1.77/pack effective January 1, 2008. In preparation for the tax increase, the Wisconsin Tobacco Prevention and Control Program, the University of Wisconsin Center for Tobacco Research and Intervention, which manages the WTQL, and the state's quitline service provider, Free & Clear, Inc., collaborated to enhance quitline knowledge, availability, and services with the goal of increasing consumer demand for services. The enhancements included for the first time, a free 2-week supply of over-the-counter nicotine replacement medication for tobacco users who agreed to receive multi-session quitline counseling. A successful statewide earned media campaign intensified the impact of these activities, which were timed to coincide with temporal smoking-cessation behavioral patterns (i.e., New Year's resolutions). As a result, the WTQL fielded a record 27,000 calls during the first 3 months of 2008, reaching nearly 3% of adult Wisconsin smokers. This experience demonstrates that consumer demand for quitline services can be markedly enhanced through policy and communication initiatives to increase the population reach of this evidence-based treatment. Published by Elsevier Inc.

76 FR 52283 - Approval and Promulgation of Air Quality Implementation Plans; Pennsylvania; Control of Nitrogen...

Science.gov (United States)

2011-08-22

... Promulgation of Air Quality Implementation Plans; Pennsylvania; Control of Nitrogen Oxides Emissions From Glass... revisions pertain to the control of nitrogen oxide (NO X ) emissions from glass melting furnaces. EPA is..., Nitrogen dioxide, Ozone, Particulate matter, Reporting and recordkeeping requirements. Dated: August 8...

76 FR 34021 - Approval and Promulgation of Air Quality Implementation Plans; Pennsylvania; Control of Nitrogen...

Science.gov (United States)

2011-06-10

... Promulgation of Air Quality Implementation Plans; Pennsylvania; Control of Nitrogen Oxides Emissions From Glass... Pennsylvania. This revision pertains to the control of nitrogen oxide (NO X ) emissions from glass melting... protection, Air pollution control, Nitrogen dioxide, Ozone, Particulate matter, Reporting and recordkeeping...

Effect of nitrogen source on methanol oxidation and genetic diversity of methylotrophic mixed cultures enriched from pulp and paper mill biofilms.

Science.gov (United States)

Babbitt, Callie W; Lindner, Angela S

2011-04-01

Methanol-oxidizing bacteria may play an important role in the development and use of biological treatment systems for the removal of methanol from industrial effluents. Optimization of methanol degradation potential in such systems is contingent on availability of nutrients, such as nitrogen, in the most favorable form and concentration. To that end, this study examined the variation in growth, methanol degradation, and bacterial diversity of two mixed methylotrophic cultures that were provided nitrogen either as ammonium or nitrate and in three different concentrations. Methanol-degrading cultures were enriched from biofilms sampled at a pulp and paper mill and grown in liquid batch culture with methanol as the only carbon source and either ammonium or nitrate as the only added nitrogen source. Results indicate that growth and methanol removal of the mixed cultures increase directly with increased nitrogen, added in either form. However, methanol removal and bacterial diversity, as observed by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) methods, were higher when using nitrate as the nitrogen source for enrichment and growth, rather than ammonium. Based on results described here, nitrate may potentially be a better nitrogen source when enriching or working with mixed methylotrophic cultures, and possibly more effective when used as a nutrient addition to biofilters.

Combined effects of nitrogen to phosphorus ratios and nitrogen speciation on cyanobacterial metabolite concentrations in eutrophic Midwestern USA reservoirs.

NARCIS (Netherlands)

Harris, T.D.; Smith, V.H.; Graham, J.L.; Van de Waal, D.B.; Tedesco, L.P.; Clercin, N.

2016-01-01

Recent studies have shown that the total nitrogen to total phosphorus (TN:TP) ratio and nitrogen oxidation state may have substantial effects on secondary metabolite (e.g., microcystins) production in cyanobacteria. We investigated the relationship between the water column TN:TP ratio and the

New approaches for description of nitrogen chemistry in combustion

Energy Technology Data Exchange (ETDEWEB)

Hupa, M.; Kilpinen, P.; Brink, A.; Norstroem, T. [Aabo Akademi, Turku (Finland)

1996-12-01

The aim of the project is to develop novel models for a more accurate description of nitrogen oxide emissions from combustion processes and to increase the understanding of the complex details of homogeneous nitrogen reactions in combustion and gasification. The topics dealt with during 1995 include: (1) effect of Cl on CO oxidation and nitrogen reactions, (2) effect of pressure on NO reduction by SNCR (in co-operation with the project 204), (3) NH{sub 3} conversion to N{sub 2} in gasification gases by selective oxidation (in cooperation with the project 203). In addition, a literature review of the models suggested for the interaction between turbulence and a chemical gas-phase reaction has been made. A commercial CFD code, FLUENT, has also been taken into use. (author)

Cost-Effectiveness Analysis of the Residential Provisions of the 2015 IECC for Wisconsin

Energy Technology Data Exchange (ETDEWEB)

Mendon, Vrushali V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Zhao, Mingjie [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Taylor, Zachary T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Poehlman, Eric A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2016-02-15

The 2015 IECC provides cost-effective savings for residential buildings in Wisconsin. Moving to the 2015 IECC from the 2006 IECC base code is cost-effective for residential buildings in all climate zones in Wisconsin.

The Load of Lightning-induced Nitrogen Oxides and Its Impact on the Ground-level Ozone during Summertime over the Mountain West States

Science.gov (United States)

Lightning-induced nitrogen oxides (LNOX), in the presence of sunlight, volatile organic compounds and water, can be a relatively large but uncertain source for ozone (O3) and hydroxyl radical (OH) in the atmosphere. Using lightning flash data from the National Lightning Detection...

Hazardous emissions, operating practices, and air regulations at industrial wood-fired facilities in Wisconsin

International Nuclear Information System (INIS)

Hubbard, A.J.

1993-01-01

Since October of 1988 the State of Wisconsin Department of Natural Resources has regulated over four hundred substances as hazardous air pollutants. The rule regulates new as well as existing sources of air pollution in Wisconsin. Consequently, all permits to operate an air pollution source in Wisconsin must address the hazardous air emissions potential of the source. While widely perceived as a clean-burning fuel, wood is often burned in a manner which clearly results in significant emissions of very hazardous air pollutants. Research conducted on a 20 million BTU per hour wood-fired spreader stoker boiler in northern Wisconsin showed that this boiler has the potential to emit 0.022 pound of benzene and 0.012 pound of formaldehyde per ton (lb/ton) of wood fired. Recent stack tests at more than a dozen other small industrial wood-fired facilities in Wisconsin show a range of formaldehyde emissions of 0.0007--0.1950 lb/ton. Work at Birchwood Lumber ampersand Veneer showed that the benzene and formaldehyde emission rates under good firing conditions are an order of magnitude lower than the benzene and formaldehyde emission rates under poor firing conditions. This finding has supported Wisconsin's regulatory approach of encouraging wood-fired facilities to enhance the quality of the combustion process as a technique to minimize the hazardous air pollution potential of industrial wood combustion. The Wisconsin strategy is to define open-quotes good combustion technologyclose quotes through easily measurable combustion parameters rather than emission standards. This paper presents several techniques in use in Wisconsin to comply with open-quotes good combustion technologyclose quotes for industrial wood-fired furnaces. These techniques include fuel blending overfire air, furnace insulation, and proper grate design

Methane oxidation in soil profiles of Dutch and Finnish coniferous forests with different soil texture and atmospheric nitrogen deposition

NARCIS (Netherlands)

Saari, A.; Martikainen, P.J.; Ferm, A.; Ruuskanen, J.; Boer, W. de; Troelstra, S.R.; Laanbroek, H.J.

1997-01-01

We studied methane oxidation capacity in soil profiles of Dutch and Finnish coniferous forests. The Finnish sites (n = 9) had nitrogen depositions from 3 to 36 kg N ha⁻¹ a⁻¹. The deposition of N on the Dutch sites (n = 13) was higher ranging from 50 to 92 kg N ha⁻¹ a⁻¹. The Dutch sites had also

Sulfur and nitrogen co-doped carbon dots sensors for nitric oxide fluorescence quantification

Energy Technology Data Exchange (ETDEWEB)

Simões, Eliana F.C. [Centro de Investigação em Química da Universidade do Porto (CIQ-UP), Faculdade de Farmácia da Universidade de Coimbra, Pólo das Ciências da Saúde, 3000-548 Coimbra (Portugal); Centro de Investigação em Química da Universidade do Porto (CIQ-UP), Departamento de Geociências, Ambiente e Ordenamento do Território, Faculdade de Ciências da Universidade do Porto, R. Campo Alegre 687, 4169-007 Porto (Portugal); Leitão, João M.M., E-mail: jleitao@ff.uc.pt [Centro de Investigação em Química da Universidade do Porto (CIQ-UP), Faculdade de Farmácia da Universidade de Coimbra, Pólo das Ciências da Saúde, 3000-548 Coimbra (Portugal); Esteves da Silva, Joaquim C.G. [Centro de Investigação em Química da Universidade do Porto (CIQ-UP), Departamento de Geociências, Ambiente e Ordenamento do Território, Faculdade de Ciências da Universidade do Porto, R. Campo Alegre 687, 4169-007 Porto (Portugal)

2017-04-01

Microwave synthetized sulfur and nitrogen co-doped carbon dots responded selectively to nitric oxide (NO) at pH 7. Citric acid, urea and sodium thiosulfate in the proportion of 1:1:3 were used respectively as carbon, nitrogen and sulfur sources in the carbon dots microwave synthesis. For this synthesis, the three compounds were diluted in 15 mL of water and exposed for 5 min to a microwave radiation of 700 W. It is observed that the main factor contributing to the increased sensitivity and selectivity response to NO at pH 7 is the sodium thiosulfate used as sulfur source. A linear response range from 1 to 25 μM with a sensitivity of 16 μM{sup −1} and a detection limit of 0.3 μM were obtained. The NO quantification capability was assessed in standard and in fortified serum solutions. - Highlights: • S,N co-doped CDs were microwave synthetized from citric acid, urea and sodium thiosulfate. • The NO fluorescence sensing was evaluated at pH 7. • The selective and sensitive detection of NO at pH 7 was achieved. • Good NO quantification results in serum samples were obtained.

High-Surface-Area Nitrogen-Doped Reduced Graphene Oxide for Electric Double-Layer Capacitors.

Science.gov (United States)

Youn, Hee-Chang; Bak, Seong-Min; Kim, Myeong-Seong; Jaye, Cherno; Fischer, Daniel A; Lee, Chang-Wook; Yang, Xiao-Qing; Roh, Kwang Chul; Kim, Kwang-Bum

2015-06-08

A two-step method consisting of solid-state microwave irradiation and heat treatment under NH3 gas was used to prepare nitrogen-doped reduced graphene oxide (N-RGO) with a high specific surface area (1007 m(2)  g(-1) ), high electrical conductivity (1532 S m(-1) ), and low oxygen content (1.5 wt %) for electrical double-layer capacitor applications. The specific capacitance of N-RGO was 291 F g(-1) at a current density of 1 A g(-1) , and a capacitance of 261 F g(-1) was retained at 50 A g(-1) , which indicated a very good rate capability. N-RGO also showed excellent cycling stability and preserved 96 % of the initial specific capacitance after 100 000 cycles. Near-edge X-ray absorption fine-structure spectroscopy results provided evidenced for the recovery of π conjugation in the carbon networks with the removal of oxygenated groups and revealed chemical bonding of the nitrogen atoms in N-RGO. The good electrochemical performance of N-RGO is attributed to its high surface area, high electrical conductivity, and low oxygen content. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Sulfur and nitrogen co-doped carbon dots sensors for nitric oxide fluorescence quantification

International Nuclear Information System (INIS)

Simões, Eliana F.C.; Leitão, João M.M.; Esteves da Silva, Joaquim C.G.

2017-01-01

Microwave synthetized sulfur and nitrogen co-doped carbon dots responded selectively to nitric oxide (NO) at pH 7. Citric acid, urea and sodium thiosulfate in the proportion of 1:1:3 were used respectively as carbon, nitrogen and sulfur sources in the carbon dots microwave synthesis. For this synthesis, the three compounds were diluted in 15 mL of water and exposed for 5 min to a microwave radiation of 700 W. It is observed that the main factor contributing to the increased sensitivity and selectivity response to NO at pH 7 is the sodium thiosulfate used as sulfur source. A linear response range from 1 to 25 μM with a sensitivity of 16 μM"−"1 and a detection limit of 0.3 μM were obtained. The NO quantification capability was assessed in standard and in fortified serum solutions. - Highlights: • S,N co-doped CDs were microwave synthetized from citric acid, urea and sodium thiosulfate. • The NO fluorescence sensing was evaluated at pH 7. • The selective and sensitive detection of NO at pH 7 was achieved. • Good NO quantification results in serum samples were obtained.

Theory and practice of nitrogen oxide absorption

International Nuclear Information System (INIS)

Counce, R.M.

1985-01-01

Nitrogen oxide (NO/sub x/) absorbers vary in purpose from bulk nitric acid production to abatement of trace NO/sub x/ concentrations from gas streams. Absorbers are typically of plate or packed tower design although some plate/packed combination towers potentially offer some useful advantages. Mathematical models for the design of NO/sub x/ absorbers vary from mechanistically based models for absorption into water and dilute HNO 3 to empirically based models for absorption into concentrated HNO 3 solutions. The NO/sub x/ content in effluent gas from modern high pressure nitric acid production towers can be reduced to well under 200 ppm. The basis for the design of low pressure NO/sub x/ absorbers for NO/sub x/ recovery or abatement has been established to a sufficient extent to be a reasonably predictive tool although published operating experience is minimal and experimental verification may be necessary for many cases. The availability of high efficiency packing potentially offers significant NO/sub x/ removal in minimal sized packed absorbers. An important issue in the design of NO/sub x/ abatement systems is the disposition of the effluent scrubber liquid. A partial recycle of this liquid to the absorber normally requires additional processes for regeneration of the scrub solution; if there is an in plant use for this effluent stream, then a substantial simplification of the system may be realized. Low pressure NO/sub x/ absorbers for the primary purpose of gaseous NO/sub x/ recovery and abatement are discussed

Nitrogen gas plasma treatment of bacterial spores induces oxidative stress that damages the genomic DNA.

Science.gov (United States)

Sakudo, Akikazu; Toyokawa, Yoichi; Nakamura, Tetsuji; Yagyu, Yoshihito; Imanishi, Yuichiro

2017-01-01

Gas plasma, produced by a short high‑voltage pulse generated from a static induction thyristor power supply [1.5 kilo pulse/sec (kpps)], was demonstrated to inactivate Geobacillus stearothermophilus spores (decimal reduction time at 15 min, 2.48 min). Quantitative polymerase chain reaction and enzyme‑linked immunosorbent assays further indicated that nitrogen gas plasma treatment for 15 min decreased the level of intact genomic DNA and increased the level of 8-hydroxy-2'-deoxyguanosine, a major product of DNA oxidation. Three potential inactivation factors were generated during operation of the gas plasma instrument: Heat, longwave ultraviolet-A and oxidative stress (production of hydrogen peroxide, nitrite and nitrate). Treatment of the spores with hydrogen peroxide (3x2‑4%) effectively inactivated the bacteria, whereas heat treatment (100˚C), exposure to UV-A (75‑142 mJ/cm2) and 4.92 mM peroxynitrite (•ONOO‑), which is decomposed into nitrite and nitrate, did not. The results of the present study suggest the gas plasma treatment inactivates bacterial spores primarily by generating hydrogen peroxide, which contributes to the oxidation of the host genomic DNA.

[Effects of nitrogen application rate on nitrate reductase activity, nitric oxide content and gas exchange in winter wheat leaves].

Science.gov (United States)

Shangguan, Zhou-Ping

2007-07-01

In this paper, the effects of different nitrogen application rates on the nitrate reductase (NR) activity, nitric oxide (NO) content and gas exchange parameters in winter wheat (Triticum aestivum L.) leaves from tillering stage to heading stage and on grain yield were studied. The results showed that the photosynthetic rate (P(n)), transpiration rate (T(r)) and instantaneous water use efficiency (IWUE) of leaves as well as the grain yield were increased with increasing nitrogen application rate first but decreased then, with the values of all these parameters reached the highest in treatment N180. The NR activity increased with increasing nitrogen application rate, and there was a significant linear correlation between NR activity and NO content at tillering and jointing stages (R2 > or = 0.68, n = 15). NO content had a quadratic positive correlation with stomatal conductance (G(s)) (R2 > or = 0.43, n = 15). The lower NO content produced by lower NR activity under lower nitrogen application rate promoted the stoma opened, while the higher NO content produced by higher NR activity under higher nitrogen application rate induced the stoma closed. Although the leaf NO content had a quadratic positive correlation with stomatal conductance (R2 > or = 0.36, n = 15), no remarkable correlation was observed between NR activity and NO content at heading stage, suggesting that nitrogen fertilization could not affect leaf NO content through promoting NR activity, and further more, regulate the stomatal action. Under appropriate nitrogen application the leaf NR activity and NO content were lower, G(s), T(r) and IWUE were higher, and thus, the crop had a better drought-resistant ability, higher P(n), and higher grain yield.

Simultaneous stripping recovery of ammonia-nitrogen and precipitation of manganese from electrolytic manganese residue by air under calcium oxide assist.

Science.gov (United States)

Chen, Hongliang; Liu, Renlong; Shu, Jiancheng; Li, Wensheng

2015-01-01

Leaching tests of electrolytic manganese residue (EMR) indicated that high contents of soluble manganese and ammonia-nitrogen posed a high environmental risk. This work reports the results of simultaneous stripping recovery of ammonia-nitrogen and precipitation of manganese by air under calcium oxide assist. The ammonia-nitrogen stripping rate increased with the dosage of CaO, the air flow rate and the temperature of EMR slurry. Stripped ammonia-nitrogen was absorbed by a solution of sulfuric acid and formed soluble (NH4)2SO4 and (NH4)3H(SO4)3. The major parameters that effected soluble manganese precipitation were the dosage of added CaO and the slurry temperature. Considering these two aspects, the efficient operation conditions should be conducted with 8 wt.% added CaO, 60°C, 800 mL min(-1) air flow rate and 60-min reaction time. Under these conditions 99.99% of the soluble manganese was precipitated as Mn3O4, which was confirmed by XRD and SEM-EDS analyses. In addition, the stripping rate of ammonia-nitrogen was 99.73%. Leaching tests showed the leached toxic substances concentrations of the treated EMR met the integrated wastewater discharge standard of China (GB8978-1996).

Wisconsin's fourth forest inventory, 1983.

Science.gov (United States)

John S. Jr. Spencer; W. Brad Smith; Jerold T. Hahn; Gerhard K. Raile

1988-01-01

The fourth inventory of the timber resource of Wisconsin shows that growing-stock volume increased from 11.2 to 15.5 billion cubic feet between 1968 and 1983, and area of timberland increased from 14.5 to 14.8 million acres. Presented are analysis and statistics on forest area and timber volume, growth, mortality, removals, and projections.

Introduction to radioactive waste management issues in Wisconsin

International Nuclear Information System (INIS)

Anon.

1977-01-01

This brief focused on wastes from commercial production of electricity and various industrial, medical and research applications of radioactive materials. Only traditionally solid wastes are dealt with. It was organized into five parts. Part I presented an introduction to radioactivity - what it is and the biological hazards associated with it. Federal regulation of the management of radioactive wastes was discussed in Part II. Existing state laws and bills currently before the Wisconsin Legislature were described in Part III. Part IV gave background information on specific areas of potential inquiry related to radioactive wastes in Wisconsin. Part V summarized the issues identified in the brief. 2 figures, 7 tables

Water quality and hydrology of the Lac Vieux Desert watershed, Gogebic County, Michigan, and Vilas County, Wisconsin, 2002-04

Science.gov (United States)

Weaver, T.L.; Neff, B.P.; Ellis, J.M.

2005-01-01

Lac Vieux Desert is a prominent 6.6 square-mile lake that straddles the Michigan-Wisconsin border and forms the headwaters of the Wisconsin River. For generations, the Lac Vieux Desert Band of Lake Superior Chippewa Indians have used Lac Vieux Desert and the surrounding area for growing and harvesting wild rice, and hunting and fishing. The Lac Vieux Desert Band is concerned about the impact of lake-stage regulation on hydrology and ecology, and the impact on water quality of development along and near the shore, and recreational watercraft use and sport fishing. In 2005, the U.S. Geological Survey completed a water-resources investigation of the Lac Vieux Desert watershed in cooperation with the Lac Vieux Desert Band of Lake Superior Chippewa Indians.Water quality of Lac Vieux Desert is typical of many lakes in the northern United States. Trophic State Index calculations classify Lac Vieux Desert as a highly productive eutrophic lake. The pH of water in Lac Vieux Desert ranged from 6.5 to 9.5, and specific conductance ranged from 62 to 114 µs/cm. Chloride concentration was less than 1.5 mg/L, indicating little effect from septic-tank or road-salt input. Results indicate that the water can be classified as soft, with hardness concentrations reported as calcium carbonate ranging from 29 to 49 mg/L. Concentrations of calcium, magnesium, chloride, and other dissolved solids ranged from 47 to 77 mg/L. Alkalinity of Lac Vieux Desert ranged from 27 to 38 mg/L.Pervasive aquatic blooms, including a bloom noted during the September 2003 sampling, are apparently common in late summer. Biological productivity at Lac Vieux Desert does not appear to have changed appreciably between 1973 and 2004. In the current study, total phosphorus concentrations ranged from 0.01 to 0.064 mg/L and dissolved nitrite plus nitrate nitrogen concentrations ranged from at, or below detection limit to 0.052 mg/L. Overabundance of nutrients in Lac Vieux Desert, particularly nitrogen and phosphorus

Flood-frequency characteristics of Wisconsin streams

Science.gov (United States)

Walker, John F.; Peppler, Marie C.; Danz, Mari E.; Hubbard, Laura E.

2017-05-22

Flood-frequency characteristics for 360 gaged sites on unregulated rural streams in Wisconsin are presented for percent annual exceedance probabilities ranging from 0.2 to 50 using a statewide skewness map developed for this report. Equations of the relations between flood-frequency and drainage-basin characteristics were developed by multiple-regression analyses. Flood-frequency characteristics for ungaged sites on unregulated, rural streams can be estimated by use of the equations presented in this report. The State was divided into eight areas of similar physiographic characteristics. The most significant basin characteristics are drainage area, soil saturated hydraulic conductivity, main-channel slope, and several land-use variables. The standard error of prediction for the equation for the 1-percent annual exceedance probability flood ranges from 56 to 70 percent for Wisconsin Streams; these values are larger than results presented in previous reports. The increase in the standard error of prediction is likely due to increased variability of the annual-peak discharges, resulting in increased variability in the magnitude of flood peaks at higher frequencies. For each of the unregulated rural streamflow-gaging stations, a weighted estimate based on the at-site log Pearson type III analysis and the multiple regression results was determined. The weighted estimate generally has a lower uncertainty than either the Log Pearson type III or multiple regression estimates. For regulated streams, a graphical method for estimating flood-frequency characteristics was developed from the relations of discharge and drainage area for selected annual exceedance probabilities. Graphs for the major regulated streams in Wisconsin are presented in the report.

76 FR 57646 - Final Withdrawal of Certain Federal Aquatic Life Water Quality Criteria Applicable to Wisconsin

Science.gov (United States)

2011-09-16

... Final Withdrawal of Certain Federal Aquatic Life Water Quality Criteria Applicable to Wisconsin AGENCY... aquatic life water quality criteria applicable to Wisconsin? C. Why is the EPA not withdrawing Wisconsin's chronic endrin aquatic life use criterion for waters designated as Warm Water Sportfish and Warm Water...

Wisconsin Educators Tackle Violence Head On.

Science.gov (United States)

Jones, Katherine A.

1999-01-01

In August 1999, Wisconsin school business officials and other school administrators met with police officers to discuss cooperative ventures to ensure school safety. Conference participants attended sessions on identifying troubled students, physical security measures, safety planning, dealing with bomb threats, and prevention and punishment. (MLH)

Libraries in Wisconsin Institutions: Status Report.

Science.gov (United States)

Merriam, Elizabeth B.

The Wisconsin Library Association Round Table of Hospitals and Institutional Librarians became concerned about adequate funding of institutional libraries; the right of institutionalized persons to read and to have educational, legal, and recreational materials; and the development of staff libraries for treatment, rehabilitation, and research…

Effect of exhaust gas recirculation on diesel engine nitrogen oxide reduction operating with jojoba methyl ester

Energy Technology Data Exchange (ETDEWEB)

Saleh, H.E. [Mechanical Power Department, Faculty of Engineering, Mattaria, Helwan University, 9 k Eltaaweniat, Nasr Road, P.O. Box 11718, Cairo (Egypt)

2009-10-15

Jojoba methyl ester (JME) has been used as a renewable fuel in numerous studies evaluating its potential use in diesel engines. These studies showed that this fuel is good gas oil substitute but an increase in the nitrogenous oxides emissions was observed at all operating conditions. The aim of this study mainly was to quantify the efficiency of exhaust gas recirculation (EGR) when using JME fuel in a fully instrumented, two-cylinder, naturally aspirated, four-stroke direct injection diesel engine. The tests were carried out in three sections. Firstly, the measured performance and exhaust emissions of the diesel engine operating with diesel fuel and JME at various speeds under full load are determined and compared. Secondly, tests were performed at constant speed with two loads to investigate the EGR effect on engine performance and exhaust emissions including nitrogenous oxides (NO{sub x}), carbon monoxide (CO), unburned hydrocarbons (HC) and exhaust gas temperatures. Thirdly, the effect of cooled EGR with high ratio at full load on engine performance and emissions was examined. The results showed that EGR is an effective technique for reducing NO{sub x} emissions with JME fuel especially in light-duty diesel engines. With the application of the EGR method, the CO and HC concentration in the engine-out emissions increased. For all operating conditions, a better trade-off between HC, CO and NO{sub x} emissions can be attained within a limited EGR rate of 5-15% with very little economy penalty. (author)

Pyrolysis of biomass in a semi-industrial scale reactor: Study of the fuel-nitrogen oxidation during combustion of volatiles

International Nuclear Information System (INIS)

Mura, E.; Debono, O.; Villot, A.; Paviet, F.

2013-01-01

In this work, an experimental study of the NOx-fuel formation, carried out on a semi-industrial scale reactor during combustion of volatiles of the pyrolysis, is performed. Two different biomasses with different nitrogen contents such as a mixture of organic sludge and wood were tested. Results show that the temperature of pyrolysis does not obviously affect the production of NOx-fuel because of the most active precursors (NH 3 and HCN) are already released at low temperatures (400 °C). In the case of sludge mixture, the combustion conditions play the discriminating role in the production of NOx-fuel: the higher the excess air ratio the larger the production of nitrogen oxides from N-fuel. -- Highlights: • An experimental study of the pyrolysis of biomass from waste has been carried out. • The study consists in the analysis of NOx-fuel production during combustion. • The temperature of pyrolysis does not affect the production of NOx. • Only a small part of the N-fuel released in the volatile fraction is oxidized. • In the case of sewage sludge the excess air ratio affects the NOx production

Reduction of nitrogen oxides from simulated exhaust gas by using plasma-catalytic process

International Nuclear Information System (INIS)

Mok, Young Sun; Koh, Dong Jun; Shin, Dong Nam; Kim, Kyong Tae

2004-01-01

Removal of nitrogen oxides (NO x ) using a nonthermal plasma reactor (dielectric-packed bed reactor) combined with monolith V 2 O 5 /TiO 2 catalyst was investigated. The effect of initial NO x concentration, feed gas flow rate (space velocity), humidity, and reaction temperature on the removal of NO x was examined. The plasma reactor used can be energized by either ac or pulse voltage. An attempt was made to utilize the electrical ignition system of an internal combustion engine as a high-voltage pulse generator for the plasma reactor. When the plasma reactor was energized by the electrical ignition system, NO was readily oxidized to NO 2 . Performance was as good as with ac energization. Increasing the fraction of NO 2 in NO x , which is the main role of the plasma reactor, largely enhanced the NO x removal efficiency. In the plasma-catalytic reactor, the increases in initial NO x concentration, space velocity (feed gas flow rate) and humidity lowered the NO x removal efficiency. However, the reaction temperature in the range up to 473 K did not significantly affect the NO x removal efficiency in the presence of plasma discharge

Modelling the effect of injection pressure on heat release parameters and nitrogen oxides in direct injection diesel engines

Directory of Open Access Journals (Sweden)

Yüksek Levent

2014-01-01

Full Text Available Investigation and modelling the effect of injection pressure on heat release parameters and engine-out nitrogen oxides are the main aim of this study. A zero-dimensional and multi-zone cylinder model was developed for estimation of the effect of injection pressure rise on performance parameters of diesel engine. Double-Wiebe rate of heat release global model was used to describe fuel combustion. extended Zeldovich mechanism and partial equilibrium approach were used for modelling the formation of nitrogen oxides. Single cylinder, high pressure direct injection, electronically controlled, research engine bench was used for model calibration. 1000 and 1200 bars of fuel injection pressure were investigated while injection advance, injected fuel quantity and engine speed kept constant. The ignition delay of injected fuel reduced 0.4 crank angle with 1200 bars of injection pressure and similar effect observed in premixed combustion phase duration which reduced 0.2 crank angle. Rate of heat release of premixed combustion phase increased 1.75 % with 1200 bar injection pressure. Multi-zone cylinder model showed good agreement with experimental in-cylinder pressure data. Also it was seen that the NOx formation model greatly predicted the engine-out NOx emissions for both of the operation modes.

Nitrogen-Based Diazeniumdiolates: Versatile Nitric Oxide-Releasing Compounds for Biomedical Research and Potential Clinical Applications

Science.gov (United States)

Saavedra, Joseph E.; Keefer, Larry K.

2002-12-01

Nitric oxide-generating ions of the nitrogen-diazeniumdiolate class with the general structure R1R2N-[N(O)NO]1 have been prepared by exposing primary, secondary, and polyamines to nitric oxide (NO). The resulting complexes regenerate bioactive NO at physiological pH with half-lives ranging from 2 seconds to 20 hours. An important goal in our research is to deliver NO to a specific organ or cell type where it is needed without affecting other NO-sensitive parts of the anatomy. By taking advantage of the remarkable chemical versatility of diazeniumdiolates, we have developed general strategies to prepare either tissue-selective NO donor drugs or materials containing NO delivery agents that can be physically placed near the target sites. Inhibition of blood coagulation, induction of penile erection, relief of pulmonary hypertension, and reversal of cerebral vasospasm are a few examples of their potential clinical applications. See Featured Molecules.

Lyme disease in Wisconsin: epidemiologic, clinical, serologic, and entomologic findings.

Science.gov (United States)

Davis, J P; Schell, W L; Amundson, T E; Godsey, M S; Spielman, A; Burgdorfer, W; Barbour, A G; LaVenture, M; Kaslow, R A

1984-01-01

In 1980-82, 80 individuals (71 Wisconsin residents) had confirmed Lyme disease (LD-c) reported; 39 additional patients had probable or possible LD. All cases of LD-c occurred during May-November; 73 percent occurred during June-July; 54 (68 percent) occurred in males. The mean age was 38.7 years (range, 7-77 years). Among LD-c patients, likely exposure to the presumed vector Ixodes dammini (ID) occurred in 22 different Wisconsin counties. Antibodies to the ID spirochete that causes LD occurred in 33 of 49 LD-c cases versus 0 of 18 in ill controls (p less than .001) and in 13 of 26 LD-c cases treated with penicillin or tetracycline versus 16 of 19 LD-c cases not treated. Early antibiotic therapy appears to blunt the antibody response to the ID spirochete. Regional tick surveys conducted in Wisconsin during each November in 1979-82 have demonstrated regions of greater density of ID. Utilizing comparable tick collection in these surveys, increases were noted in the percentage of deer with ID from 24 percent (31/128) in 1979 to 38 percent (58/152) in 1981, in the standardized mean value of ID/deer from 1.0 in 1979 to 2.2 in 1981, in the percentage of ID of the total ticks collected from 13 percent in 1979 to 71 percent in 1981, or in the ratio of ID to Dermacentor albipictus ticks from 0.14 in 1979 to 2.44 in 1981. However, a reduction in the density of ID/deer was noted generally throughout Wisconsin in 1982 when compared to 1981. LD is widespread in Wisconsin, with ecologic and clinical features similar to those occurring along the eastern seaboard.

Diffusion of oxygen in nitrogen in the pores of graphite. Preliminary results on the effect of oxidation on diffusivity

Energy Technology Data Exchange (ETDEWEB)

Hewitt, G. F.; Sharratt, E. W.

1962-10-15

Preliminary results are reported from an experimental study of the effect of burnoff on the diffusivity of oxygen in nitrogen within the pores of graphite. It is found that the ratio of effective diffusivity to ''free gas'' diffusivity changes about four-fold in the range 0-9% total oxidation. The viscous permeability, B₀, increases in almost the same proportion over the same range.

Enzymology and ecology of the nitrogen cycle.

Science.gov (United States)

Martínez-Espinosa, Rosa María; Cole, Jeffrey A; Richardson, David J; Watmough, Nicholas J

2011-01-01

The nitrogen cycle describes the processes through which nitrogen is converted between its various chemical forms. These transformations involve both biological and abiotic redox processes. The principal processes involved in the nitrogen cycle are nitrogen fixation, nitrification, nitrate assimilation, respiratory reduction of nitrate to ammonia, anaerobic ammonia oxidation (anammox) and denitrification. All of these are carried out by micro-organisms, including bacteria, archaea and some specialized fungi. In the present article, we provide a brief introduction to both the biochemical and ecological aspects of these processes and consider how human activity over the last 100 years has changed the historic balance of the global nitrogen cycle.

The evolution of Wisconsin's urban FIA program—yesterday today and tomorrow

Science.gov (United States)

Andrew M. Stoltman; Richard B. Rideout

2015-01-01

In 2002, Wisconsin was part of two pilot projects in cooperation with the US Forest Service. The first was a street tree assessment, and the second was an urban FIA project. The data generated by these pilots changed the way that Wisconsin DNRs’ Urban Forestry Program conducts its business. Although there have been several urban FIA pilot projects throughout the U.S.,...

Geodemographic Features of Human Blastomycosis in Eastern Wisconsin

Directory of Open Access Journals (Sweden)

Megan E. Huber

2016-04-01

Full Text Available Purpose: Blastomycosis is an endemic fungal infection. In rural northern Wisconsin, blastomycosis cases are associated with certain environmental features including close proximity to waterways. Other studies have associated blastomycosis with particular soil chemicals. However, blastomycosis also occurs in urban and suburban regions. We explored the geodemographic associations of blastomycosis cases in the more urban/suburban landscape of eastern Wisconsin. Methods: We conducted a retrospective study of 193 laboratory-identified blastomycosis cases in a single eastern Wisconsin health system, 2007–2015. Controls were 250 randomly selected cases of community-diagnosed pneumonia from a similar time period. Geographic features of home addresses were explored using Google Maps. Categorical variables were analyzed with chi-square or Fisher’s exact tests and continuous variables by two-sample t-tests. Stepwise regression followed by binary logistic regression was used for multivariable analysis. Results: Compared to pneumonia cases, blastomycosis cases were younger (47.7 vs. 55.3 years and more likely to be male (67.9% vs. 45.6%, nonwhite (23.2% vs. 9.7% and machinists, automobile workers/mechanics or construction workers (32.7% vs. 7.2%; P 0.5 acres (30.4% vs. 14.2%, P = 0.0002, be < 0.25 miles from an automobile repair facility or junkyard (35.9% vs. 19.4%, P = 0.0005, and be < 0.1 miles from a park, forest or farm field (54.9% vs. 39.6%, P = 0.002. Only the latter association remained on multivariable analysis. Conclusions: Eastern Wisconsin blastomycosis case subjects were younger, more often male and more likely to live near parks/forests/fields. Novel associations of blastomycosis cases with machinery- and automobile-related occupations and/or facilities should be further explored.

Correction of aggregative thrombocytes activity in patients with unstable angina by THz irradiation of nitrogen oxide occurrence at in vitro conditions

Directory of Open Access Journals (Sweden)

Vyacheslav F. Kirichuk

2013-11-01

Full Text Available There had been shown a normalizing effect of THz radiation of MEAS (molecular emission and absorption spectrum of 400 GHz nitrogen oxide occurrence on aggregation parameters of thrombocytes in patients with unstable angina at in vitro conditions. 180 patients with an unstable angina had been involved in to the research.

Divided Wisconsin: Partisan Spatial Electoral Realignment

Science.gov (United States)

Zaniewski, Kazimierz J.; Simmons, James R.

2016-01-01

When the Republican and Democratic presidential candidates head into the general election this fall, they will be courting votes from a statewide electorate that has dramatically shifted over time, mirroring the political polarization that is happening across the country. Over the last three decades, Wisconsin's political geography has evolved…

Removal of 14C from nitrogen annulus gas

International Nuclear Information System (INIS)

Cheh, C.H.

1985-01-01

A dry, ambient temperature process using Ca(OH) 2 as the sorbent to remove 14 CO 2 from moderator cover gas was further developed to remove 14 C from the extremely dry nitrogen annulus gas. Thermal gravimetric analysis was carried out to study the thermal stability of Ca(OH) 2 and the CO 2 -Ca(OH) 2 reaction at elevated temperatures under extremely low humidity conditions. Results shows that to achieve high utilization and avoid decomposition of Ca(OH) 2 , humidification of the annulus gas was necessary at high or low temperatures. Results of the bench scale (1-10 L/min) oxidizer study showed that, with 0.5% Pd or alumina as the catalyst, it was possible to achieve complete oxidation of CO and over 80% oxidation of CH 4 with 1% hydrogen in the nitrogen. The gas superficial velocity should be less than or equal to30 cm/s and the residence time greater than or equal to0.5 s. A pilot scale (up to 160 L/min) system including a catalytic oxidizer, a humidifier/demister, a Ca(OH) 2 reactor, a condenser/demister and regenerable molecular sieve dryers, was assembled and tested with simulated nitrogen annulus gas. Results showed that complete oxidation of the CO and 60-100% oxidation of the CH 4 with 0.5% H 2 in the simulated gas were achieved in the pilot plant. The CO 2 concentration was reduced from 30-60 μL/L at the inlet of the Ca(OH) 2 reactor to 1 μL/L or less at the outlet. After modifications of the dryer to overcome the problems encountered, the simulated annulus gas was dried to 0 C dew point before recirculation. Equipment specifications and operating conditions of a 14 C removal system for nitrogen annulus gas are summarized

Three Dimensional Nitrogen-Doped and Nitrogen, Sulfur-Codoped Graphene Hydrogels for Electrode Materials in Supercapacitors.

Science.gov (United States)

Yuan, Zhao; Qiao, Fei; Wang, Guiqiang; Zhou, Jin; Cui, Hongyou; Zhuo, Shuping; Xing, Ling-Bao

2018-08-01

In present work, reduced graphene oxide hydrogels (RGOHs) with three-dimensional (3D) porous structure are prepared through chemical reduction method by using aminourea (NRGOHs) and aminothiourea (NSRGOHs) as reductants. The as-prepared RGOHs are considered not only as promising electrode materials for supercapacitors, but also the doping of nitrogen (aminourea, NRGOHs) or nitrogen/sulfur (aminothiourea, NSRGOHs) can improve electrochemical performance through faradaic pseudocapacitance. The optimized samples have been prepared by controlling the mass ratios of graphene oxide (GO) to aminourea or aminothiourea to be 1:1, 1:2 and 1:5, respectively. With adding different amounts of aminourea or aminothiourea, the obtained RGOHs exhibited different electrochemical performance in supercapacitors. With increasing the dosage of the reductants, the RGOHs revealed better specific capacitances. Moreover, NSRGOHs with nitrogen, sulfur-codoping exhibited better capacitance performance than that of NRGOHs with only nitrogen-doping. NSRGOHs showed excellent capacitive performance with a very high specific capacitance up to 232.2, 323.3 and 345.6 F g-1 at 0.2 A g-1, while NRGOHs showed capacitive performance with specific capacitance up to 220.6, 306.5 and 332.7 F g-1 at 0.2 A g-1. This provides a strategy to improve the capacitive properties of RGOHs significantly by controlling different doping the materials.

Effect of increased fuel temperature on emissions of oxides of nitrogen from a gas turbine combustor burning ASTM jet-A fuel

Science.gov (United States)

Marchionna, N. R.

1974-01-01

An annular gas turbine combustor was tested with heated ASTM Jet-A fuel to determine the effect of increased fuel temperature on the formation of oxides of nitrogen. Fuel temperature ranged from ambient to 700 K. The NOx emission index increased at a rate of 6 percent per 100 K increase in fuel temperature.

Effect of feed-gas humidity on nitrogen atmospheric-pressure plasma jet for biological applications.

Science.gov (United States)

Stephan, Karl D; McLean, Robert J C; DeLeon, Gian; Melnikov, Vadim

2016-11-14

We investigate the effect of feed-gas humidity on the oxidative properties of an atmospheric-pressure plasma jet using nitrogen gas. Plasma jets operating at atmospheric pressure are finding uses in medical and biological settings for sterilization and other applications involving oxidative stress applied to organisms. Most jets use noble gases, but some researchers use less expensive nitrogen gas. The feed-gas water content (humidity) has been found to influence the performance of noble-gas plasma jets, but has not yet been systematically investigated for jets using nitrogen gas. Low-humidity and high-humidity feed gases were used in a nitrogen plasma jet, and the oxidation effect of the jet was measured quantitatively using a chemical dosimeter known as FBX (ferrous sulfate-benzoic acid-xylenol orange). The plasma jet using high humidity was found to have about ten times the oxidation effect of the low-humidity jet, as measured by comparison with the addition of measured amounts of hydrogen peroxide to the FBX dosimeter. Atmospheric-pressure plasma jets using nitrogen as a feed gas have a greater oxidizing effect with a high level of humidity added to the feed gas.

Nitrogen-removal performance and community structure of nitrifying bacteria under different aeration modes in an oxidation ditch.

Science.gov (United States)

Guo, Chang-Zi; Fu, Wei; Chen, Xue-Mei; Peng, Dang-Cong; Jin, Peng-Kang

2013-07-01

Oxidation-ditch operation modes were simulated using sequencing batch reactors (SBRs) with alternate stirring and aerating. The nitrogen-removal efficiencies and nitrifying characteristics of two aeration modes, point aeration and step aeration, were investigated. Under the same air-supply capacity, oxygen dissolved more efficiently in the system with point aeration, forming a larger aerobic zone. The nitrifying effects were similar in point aeration and step aeration, where the average removal efficiencies of NH4(+) N were 98% and 96%, respectively. When the proportion of anoxic and oxic zones was 1, the average removal efficiencies of total nitrogen (TN) were 45% and 66% under point aeration and step aeration, respectively. Step aeration was more beneficial to both anoxic denitrification and simultaneous nitrification and denitrification (SND). The maximum specific ammonia-uptake rates (AUR) of point aeration and step aeration were 4.7 and 4.9 mg NH4(+)/(gMLVSS h), respectively, while the maximum specific nitrite-uptake rates (NUR) of the two systems were 7.4 and 5.3 mg NO2(-)-N/(gMLVSS h), respectively. The proportions of ammonia-oxidizing bacteria (AOB) to all bacteria were 5.1% under point aeration and 7.0% under step aeration, and the proportions of nitrite-oxidizing bacteria (NOB) reached 6.5% and 9.0% under point and step aeration, respectively. The dominant genera of AOB and NOB were Nitrosococcus and Nitrospira, which accounted for 90% and 91%, respectively, under point aeration, and the diversity of nitrifying bacteria was lower than under step aeration. Point aeration was selective of nitrifying bacteria. The abundance of NOB was greater than that of AOB in both of the operation modes, and complete transformation of NH4(+) N to NO3(-)-N was observed without NO2(-)-N accumulation. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effect of Nitrogen Oxides on Elemental Mercury Removal by Nanosized Mineral Sulfide.

Science.gov (United States)

Li, Hailong; Zhu, Lei; Wang, Jun; Li, Liqing; Lee, Po-Heng; Feng, Yong; Shih, Kaimin

2017-08-01

Because of its large surface area, nanosized zinc sulfide (Nano-ZnS) has been demonstrated in a previous study to be efficient for removal of elemental mercury (Hg 0 ) from coal combustion flue gas. The excellent mercury adsorption performance of Nano-ZnS was found to be insusceptible to water vapor, sulfur dioxide, and hydrogen chloride. However, nitrogen oxides (NO X ) apparently inhibited mercury removal by Nano-ZnS; this finding was unlike those of many studies on the promotional effect of NO X on Hg 0 removal by other sorbents. The negative effect of NO X on Hg 0 adsorption over Nano-ZnS was systematically investigated in this study. Two mechanisms were identified as primarily responsible for the inhibitive effect of NO X on Hg 0 adsorption over Nano-ZnS: (1) active sulfur sites on Nano-ZnS were oxidized to inactive sulfate by NO X ; and (2) the chemisorbed mercury, i.e., HgS, was reduced to Hg 0 by NO X . This new insight into the role of NO X in Hg 0 adsorption over Nano-ZnS can help to optimize operating conditions, maximize Hg 0 adsorption, and facilitate the application of Nano-ZnS as a superior alternative to activated carbon for Hg 0 removal using existing particulate matter control devices in power plants.

The effect of Ti and Nb on nitrogen dissolution reaction in stainless steel melt

International Nuclear Information System (INIS)

Jang, Min Whan; Hong, In Kook; Pak, Jong Jin; Song, Hyo Seok; Lee, Yong Deuk

2002-01-01

A kinetic study of nitrogen dissolution in STS304 stainless steel melt containing Ti and Nb has been carried out at 1500 degree C using an induction furnace and a levitation melting furnace. At low O and S levels, the nitrogen dissolution rate showed the first-order kinetics being controlled by the mass transfer of nitrogen in the melt. Ti addition to STS304 stainless melt significantly retarded the nitrogen dissolution rate by the formation of solid Ti oxide layer adhered on the melt surface. Nb did not affect the rate of nitrogen dissolution. In the levitation melting experiment where the oxide layer was removed from the melt surface, Ti did not retard the nitrogen dissolution rate. Simultaneous addition of Ti and Al increased the dissolution rate by the formation of non-wetting Al 2 O 3 on the melt surface. A small addition of CaO-Al 2 O 3 synthetic flux to Ti containing melt was very effective to remove the oxide layer, hence to increase the nitrogen dissolution rate

The effect of Ti and Nb on nitrogen dissolution reaction in stainless steel melt

Energy Technology Data Exchange (ETDEWEB)

Jang, Min Whan; Hong, In Kook; Pak, Jong Jin [Hanyang Univ., Ansan (Korea, Republic of); Song, Hyo Seok; Lee, Yong Deuk [POSCO, Pohang (Korea, Republic of)

2002-03-01

A kinetic study of nitrogen dissolution in STS304 stainless steel melt containing Ti and Nb has been carried out at 1500 degree C using an induction furnace and a levitation melting furnace. At low O and S levels, the nitrogen dissolution rate showed the first-order kinetics being controlled by the mass transfer of nitrogen in the melt. Ti addition to STS304 stainless melt significantly retarded the nitrogen dissolution rate by the formation of solid Ti oxide layer adhered on the melt surface. Nb did not affect the rate of nitrogen dissolution. In the levitation melting experiment where the oxide layer was removed from the melt surface, Ti did not retard the nitrogen dissolution rate. Simultaneous addition of Ti and Al increased the dissolution rate by the formation of non-wetting Al{sub 2}O{sub 3} on the melt surface. A small addition of CaO-Al{sub 2}O{sub 3} synthetic flux to Ti containing melt was very effective to remove the oxide layer, hence to increase the nitrogen dissolution rate.

Microbial nitrogen transformation potential in surface run-off leachate from a tropical landfill

International Nuclear Information System (INIS)

Mangimbulude, Jubhar C.; Straalen, Nico M. van; Röling, Wilfred F.M.

2012-01-01

Highlights: ► Microbial nitrogen transformations can alleviate toxic ammonium discharge. ► Aerobic ammonium oxidation was rate-limiting in Indonesian landfill leachate. ►Organic nitrogen ammonification was most dominant. ► Anaerobic nitrate reduction and ammonium oxidation potential were also high. ► A two-stage aerobic-anaerobic nitrogen removal system needs to be implemented. - Abstract: Ammonium is one of the major toxic compounds and a critical long-term pollutant in landfill leachate. Leachate from the Jatibarang landfill in Semarang, Indonesia, contains ammonium in concentrations ranging from 376 to 929 mg N L −1 . The objective of this study was to determine seasonal variation in the potential for organic nitrogen ammonification, aerobic nitrification, anaerobic nitrate reduction and anaerobic ammonium oxidation (anammox) at this landfilling site. Seasonal samples from leachate collection treatment ponds were used as an inoculum to feed synthetic media to determine potential rates of nitrogen transformations. Aerobic ammonium oxidation potential ( −1 h −1 ) was more than a hundred times lower than the anaerobic nitrogen transformation processes and organic nitrogen ammonification, which were of the same order of magnitude. Anaerobic nitrate oxidation did not proceed beyond nitrite; isolates grown with nitrate as electron acceptor did not degrade nitrite further. Effects of season were only observed for aerobic nitrification and anammox, and were relatively minor: rates were up to three times higher in the dry season. To completely remove the excess ammonium from the leachate, we propose a two-stage treatment system to be implemented. Aeration in the first leachate pond would strongly contribute to aerobic ammonium oxidation to nitrate by providing the currently missing oxygen in the anaerobic leachate and allowing for the growth of ammonium oxidisers. In the second pond the remaining ammonium and produced nitrate can be converted by a

The oxidation of hydrogen cyanide and related chemistry

DEFF Research Database (Denmark)

Dagaut, Philippe; Glarborg, Peter; Alzueta, Maria U.

2008-01-01

For modeling the formation of nitrogen oxides in combustion via both the prompt-NO and the fuel-NO mechanisms, as well as for modeling the reduction of nitrogen oxides via reburning, a good knowledge of the kinetics of oxidation of hydrogen cyanide (HCN) is required. The formation routes to HCN a...

Method of removing nitrogen monoxide from a nitrogen monoxide-containing gas using a water-soluble iron ion-dithiocarbamate, xanthate or thioxanthate

Science.gov (United States)

Liu, D. Kwok-Keung; Chang, Shih-Ger

1987-08-25

The present invention relates to a method of removing of nitrogen monoxide from a nitrogen monoxide-containing gas which method comprises contacting a nitrogen oxide-containing gas with an aqueous solution of water soluble organic compound-iron ion chelate complex. The NO absorption efficiency of ferrous urea-dithiocarbamate and ferrous diethanolamine-xanthate as a function of time, oxygen content and solution ph is presented. 3 figs., 1 tab.

Regulatory Drivers of Multimedia Reactive Nitrogen Research (Invited)

Science.gov (United States)

Shaw, S. L.; Knipping, E.; Kumar, N.

2010-12-01

The presence of nitrogenous compounds can impact biogeochemical processes in the atmosphere, oceans and freshwater, and land surfaces. As a result, a number of regulations exist that are intended to control the amount and forms of nitrogen present in the environment. These range from the newly proposed Transport Rule, both the primary and secondary National Ambient Air Quality Standards (NAAQS) for nitrogen oxide targeted at ozone and particulate matter formation and nitrogen deposition, and waterbody requirements such as the Total Maximum Daily Load. This talk will cover a subset of research activities at EPRI that inform environmental nitrogen concerns. A multimedia modeling framework has facilitated effect studies of atmospheric loadings on ecosystems. Improvements in emissions estimates, such as for mobile sources, suggest large current underestimates that will substantially impact air quality modeling of nitrogen oxides. Analyses of wintertime nitrate formation in the northern U.S. are demonstrating the roles of NH3 and NOx in particle formation there. Novel measurements of power plant stack emissions suggest operating configurations can influence the isotopic composition of emitted NOx. Novel instruments for ambient measurements of nitrogen, and suggestions for improved deposition estimates, are being developed. EPRI results suggest that multimedia solutions across multiple economic sectors, such as electrification of a wide variety of engines and water quality treatment and trading, have the potential to improve environmental quality effectively.

Nitrogen-doped carbon monolith for alkaline supercapacitors and understanding nitrogen-induced redox transitions.

Science.gov (United States)

Wang, Da-Wei; Li, Feng; Yin, Li-Chang; Lu, Xu; Chen, Zhi-Gang; Gentle, Ian R; Lu, Gao Qing; Cheng, Hui-Ming

2012-04-23

A nitrogen-doped porous carbon monolith was synthesized as a pseudo-capacitive electrode for use in alkaline supercapacitors. Ammonia-assisted carbonization was used to dope the surface with nitrogen heteroatoms in a way that replaced carbon atoms but kept the oxygen content constant. Ammonia treatment expanded the micropore size-distributions and increased the specific surface area from 383 m(2) g(-1) to 679 m(2) g(-1). The nitrogen-containing porous carbon material showed a higher capacitance (246 F g(-1)) in comparison with the nitrogen-free one (186 F g(-1)). Ex situ electrochemical spectroscopy was used to investigate the evolution of the nitrogen-containing functional groups on the surface of the N-doped carbon electrodes in a three-electrode cell. In addition, first-principles calculations were explored regarding the electronic structures of different nitrogen groups to determine their relative redox potentials. We proposed possible redox reaction pathways based on the calculated redox affinity of different groups and surface analysis, which involved the reversible attachment/detachment of hydroxy groups between pyridone and pyridine. The oxidation of nitrogen atoms in pyridine was also suggested as a possible reaction pathway. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Water Injection on Commercial Aircraft to Reduce Airport Nitrogen Oxides

Science.gov (United States)

Daggett, David L.; Hendricks, Robert C.; Fucke, Lars; Eames, David J. H.

2010-01-01

The potential nitrogen oxide (NO(x) reductions, cost savings, and performance enhancements identified in these initial studies of waterinjection technology strongly suggest that it be further pursued. The potential for engine maintenance cost savings from this system should make it very attractive to airline operators and assure its implementation. Further system tradeoff studies and engine tests are needed to answer the optimal system design question. Namely, would a low-risk combustor injection system with 70- to 90-percent NO(x) reduction be preferable, or would a low-pressure compressor (LPC) misting system with only 50-percent NO(x) reduction but larger turbine inlet temperature reductions be preferable? The low-pressure compressor injection design and operability issues identified in the report need to be addressed because they might prevent implementation of the LPC type of water-misting system. If water-injection technology challenges are overcome, any of the systems studied would offer dramatic engine NO(x) reductions at the airport. Coupling this technology with future emissions-reduction technologies, such as fuel-cell auxiliary power units will allow the aviation sector to address the serious challenges of environmental stewardship, and NO(x) emissions will no longer be an issue at airports.

Numerical Research of Nitrogen Oxides Formation for Justification of Modernization of P-49 Nazarovsky State District Power Plant Boiler on the Low-temperature Swirl Technology of Burning

Science.gov (United States)

Trinchenko, A. A.; Paramonov, A. P.; Skouditskiy, V. E.; Anoshin, R. G.

2017-11-01

Compliance with increasingly stringent normative requirements to the level of pollutants emissions when using organic fuel in the energy sector as a main source of heat, demands constant improvement of the boiler and furnace equipment and the power equipment in general. The requirements of the current legislation in the field of environmental protection prescribe compliance with established emission standards for both new construction and the improvement of energy equipment. The paper presents the results of numerical research of low-temperature swirl burning in P-49 Nazarovsky state district power plant boiler. On the basis of modern approaches of the diffusion and kinetic theory of burning and the analysis physical and chemical processes of a fuel chemically connected energy transition in thermal, generation and transformation of gas pollutants, the technological method of nitrogen oxides decomposition on the surface of carbon particles with the formation of environmentally friendly carbonic acid and molecular nitrogen is considered during the work of low-temperature swirl furnace. With the use of the developed model, methodology and computer program, variant calculations of the combustion process were carried out and a quantitative estimate of the emission level of the nitrogen oxides of the boiler being modernized. The simulation results the and the experimental data obtained during the commissioning and balance tests of the P-49 boiler with a new furnace are confirmed that the organization of swirl combustion has allowed to increase the efficiency of work, to reduce slagging, to significantly reduce nitrogen oxide emissions, to improve ignition and burnout of fuel.

Nitrogen doped graphene supported palladium-cobalt as a promising catalyst for methanol oxidation reaction: Synthesis, characterization and electrocatalytic performance

International Nuclear Information System (INIS)

Kiyani, Roya; Rowshanzamir, Soosan; Parnian, Mohammad Javad

2016-01-01

In this work, palladium and palladium-cobalt supported on nitrogen doped graphene as anode materials in direct methanol fuel cells is reported. A simple and low temperature solvothermal method is used to directly prepare nanoflower-like NG and then, Pd and Pd−Co nanoparticles are precipitated onto the surface of NG using a modified polyol reduction method. The synthesized electrocatalysts are characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). Cyclic voltammetry (CV), linear sweep voltammetry (LSV), chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS) are used to measure electrocatalytic methanol oxidation activity and the durability of electrocatalysts. The results show that Pd−Co/NG has better electrocatalytic activity than Pd/NG toward methanol oxidation reaction (MOR) in alkaline media that is related at the presence of cobalt atoms. In addition, chronoamperometric results indicate that Pd−Co/NG is more stable than commercial Pt/C for MOR. - Highlights: • Nitrogen doped graphene (NG) was prepared by a simple solvothermal method. • Pd and Pd−Co nanoparticles were deposited on NG by polyol reduction method. • Promoting effects of cobalt over Pd/NG for MOR were investigated. • Higher activity and enhanced durability was observed for Pd−Co/NG catalyst.

Emission of nitrous oxide during combustion of organic fuels

Energy Technology Data Exchange (ETDEWEB)

Kotler, V.R.; Gol' dberg, A.S.

1990-11-01

Analyzes formation of nitrogen oxides during combustion of coal, natural gas and mazout: chemical reactions that lead to formation of nitrous oxide during coal combustion, reaction kinetics and reaction yields, factors that influence emission of nitrogen oxides from a furnace, factors that influence formation of nitrous oxide (temperature effects, air excess ratio, coal burnout degree, etc.), effects of fuel type and its chemical composition, effects of flue gas desulfurization and denitrification methods on nitrous oxide yield. Analyses show that yield of nitrous oxide is low and does not exceed 5 cm{sup 3}/m{sup 3} flue gas (0.0005%). However chemical reactions of nitrogen oxides, sulfur dioxide and water vapor in the atmosphere are said to form additional quantities of nitrous oxide which negatively influence the ozone layer. 4 refs.

Effects of grass-clover management and cover crops on nitrogen cycling and nitrous oxide emissions in a stockless organic crop rotation

DEFF Research Database (Denmark)

Brozyna, Michal Adam; Petersen, Søren O; Chirinda, Ngoni

2013-01-01

Nitrogen (N) supply in stockless organic farming may be improved through use of grass-clover for anaerobic digestion, producing biogas and digested manure for use as fertilizer in the crop rotation. We studied the effects of grass-clover management on N cycling, nitrous oxide (N2O) emissions...... in the rotation (spring barley, potato and winter wheat); actual digestion of grass-clover cuttings was not possible, instead digested pig manure was used as substitute for digested grass-clover. Nitrous oxide fluxes were monitored between April 2008 and May 2009. In general, application of digested manure had...

Nitrogen oxides emission of mobile equipment in the port of Rotterdam. Consequences for nitrogen dioxide concentration, nitrogen deposition and a deduction of emission factors for container and bulk businesses; Stikstofoxidenemissies van mobiele werktuigen in de Rotterdamse haven. Gevolgen voor stikstofdioxide concentratie, stikstofdepositie, en een afleiding van emissiefactoren voor container- en droge bulk bedrijven

Energy Technology Data Exchange (ETDEWEB)

Okkerse, W J.H.; De Gier, C W

2011-08-15

In container terminals, dry bulk businesses and construction sites in the port of Rotterdam, the Netherlands, large masses of goods are transported by means of diesel-fuelled equipment every year. The combustion of diesel in this equipment results in emissions of nitrogen oxides (NOx) and particulate matter. This study has calculated the amounts of NOx emissions of the involved businesses based on detailed data on the composition of the equipment fleet of six representative storage and transshipment businesses. The resulting contribution to nitrogen oxide concentration at ground level and the nitrogen deposition have been calculated with the OPS model (Operational Priority Substances) [Dutch] Bij containerterminals, droge bulk bedrijven en bouwplaatsen in de Rotterdamse haven wordt jaarlijks een grote massa aan goederen getransporteerd met behulp van dieselaangedreven apparatuur. De verbranding van diesel in deze apparatuur zorgt voor de emissie van stikstofoxiden (NOx) en stof. In dit onderzoek zijn de NOx emissies van de betrokken bedrijven berekend op basis van gedetailleerde gegevens over de samenstelling van het werktuigenpark van zes representatieve op- en overslagbedrijven. De resulterende bijdrage aan de stikstofdioxide (NO2) concentratie op leefniveau en de stikstofdepositie is berekend met het OPS-model (Operationele Prioritaire Stoffen)

Three-Dimensional Porous Nitrogen-Doped NiO Nanostructures as Highly Sensitive NO2 Sensors

Directory of Open Access Journals (Sweden)

Van Hoang Luan

2017-10-01

Full Text Available Nickel oxide has been widely used in chemical sensing applications, because it has an excellent p-type semiconducting property with high chemical stability. Here, we present a novel technique of fabricating three-dimensional porous nitrogen-doped nickel oxide nanosheets as a highly sensitive NO2 sensor. The elaborate nanostructure was prepared by a simple and effective hydrothermal synthesis method. Subsequently, nitrogen doping was achieved by thermal treatment with ammonia gas. When the p-type dopant, i.e., nitrogen atoms, was introduced in the three-dimensional nanostructures, the nickel-oxide-nanosheet-based sensor showed considerable NO2 sensing ability with two-fold higher responsivity and sensitivity compared to non-doped nickel-oxide-based sensors.

78 FR 48900 - Notice of Inventory Completion: State Historical Society of Wisconsin, Madison, WI

Science.gov (United States)

2013-08-12

.... ADDRESSES: Jennifer Kolb, Wisconsin Historical Museum, 30 North Carroll Street, Madison, WI 53703, telephone (608) 261-2461, email Jennifer.Kolb@wisconsinhistory.org . SUPPLEMENTARY INFORMATION: Notice is here... request to Jennifer Kolb, Wisconsin Historical Museum, 30 North Carroll Street, Madison, WI 53703...

Visible-light induced photocatalysis of AgCl@Ag/titanate nanotubes/nitrogen-doped reduced graphite oxide composites

Science.gov (United States)

Pan, Hongfei; Zhao, Xiaona; Fu, Zhanming; Tu, Wenmao; Fang, Pengfei; Zhang, Haining

2018-06-01

High recombination rate of photogenerated electron-hole pairs and relatively narrow photoresponsive range of TiO2-based photocatalysts are the remaining challenges for their practical applications. To address such challenges, photocatalysts consisting of AgCl covered Ag nanoparticles (AgCl@Ag), titanate nanotubes (TiNT), and nitrogen-doped reduced graphite oxide (rGON) are fabricated through alkaline hydrothermal process, followed by deposition and in situ surface-oxidation of silver nanoparticles. In the synthesized photocatalysts, the titanate nanotubes have average length of about 100 nm with inner diameters of about 5 nm and the size of the formed silver nanoparticles is in the range of 50-100 nm. The synthesized photocatalyst degrades almost all the model organic pollutant Rhodamine B in 35 min and remains 90% of photocatalytic efficiency after 5 degradation cycles under visible light irradiation. Since the oxidant FeCl3 applied for oxidation of surface Ag to AgCl is difficult to be completely removed due to the high adsorption capacity of TiNT and rGON, the effect of reside Fe atoms on photocatalytic activity is evaluated and the results reveal that the residue Fe atom only affect the initial photodegradation performance. Nevertheless, the results demonstrate that the formed composite catalyst is a promising candidate for antibiosis and remediation in aquatic environmental contamination.

Informed Forces for Environmental Quality, Conference Proceedings (University of Wisconsin, Green Bay, Wisconsin, March 28-29, 1968).

Science.gov (United States)

Wisconsin Univ., Green Bay.

To increase understanding of the dimensions of man's impact on his environment and the key issues involved in improving that environment through education and action was the goal of the environmental quality conference held at the University of Wisconsin, Green Bay, on March 28-29, 1968. Contained in this document are the conference…

Exhaustive Conversion of Inorganic Nitrogen to Nitrogen Gas Based on a Photoelectro-Chlorine Cycle Reaction and a Highly Selective Nitrogen Gas Generation Cathode.

Science.gov (United States)

Zhang, Yan; Li, Jinhua; Bai, Jing; Shen, Zhaoxi; Li, Linsen; Xia, Ligang; Chen, Shuai; Zhou, Baoxue

2018-02-06

A novel method for the exhaustive conversion of inorganic nitrogen to nitrogen gas is proposed in this paper. The key properties of the system design included an exhaustive photoelectrochemical cycle reaction in the presence of Cl - , in which Cl· generated from oxidation of Cl - by photoholes selectively converted NH 4 + to nitrogen gas and some NO 3 - or NO 2 - . The NO 3 - or NO 2 - was finally reduced to nitrogen gas on a highly selective Pd-Cu-modified Ni foam (Pd-Cu/NF) cathode to achieve exhaustive conversion of inorganic nitrogen to nitrogen gas. The results indicated total nitrogen removal efficiencies of 30 mg L -1 inorganic nitrogen (NO 3 - , NH 4 + , NO 3 - /NH 4 + = 1:1 and NO 2 - /NO 3 - /NH 4 + = 1:1:1) in 90 min were 98.2%, 97.4%, 93.1%, and 98.4%, respectively, and the remaining nitrogen was completely removed by prolonging the reaction time. The rapid reduction of nitrate was ascribed to the capacitor characteristics of Pd-Cu/NF that promoted nitrate adsorption in the presence of an electric double layer, eliminating repulsion between the cathode and the anion. Nitrate was effectively removed with a rate constant of 0.050 min -1 , which was 33 times larger than that of Pt cathode. This system shows great potential for inorganic nitrogen treatment due to the high rate, low cost, and clean energy source.

Wisconsin's forest statistics, 1987: an inventory update.

Science.gov (United States)

W. Brad Smith; Jerold T. Hahn

1989-01-01

The Wisconsin 1987 inventory update, derived by using tree growth models, reports 14.7 million acres of timberland, a decline of less than 1% since 1983. This bulletin presents findings from the inventory update in tables detailing timberland area, volume, and biomass.

Wisconsin Public Schools at a Glance

Science.gov (United States)

Wisconsin Department of Public Instruction, 2014

2014-01-01

"Wisconsin Public Schools at a Glance" provides in a single page document statistical information on the following topics: (1) Total number of public schools (2014-15); (2) Staff (2013-14); (3) Students (2013-14);(4) Report Cards (2013-14); (5) Attendance and Graduation (2012-13); (6) Student Performance (2013-14); and (7) School Funding.

Assessing the Social and Environmental Costs of Institution Nitrogen Footprints.