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Sample records for acid ammonia dimethylamine

  1. Free energy barrier in the growth of sulfuric acid-ammonia and sulfuric acid-dimethylamine clusters

    NASA Astrophysics Data System (ADS)

    Olenius, T.; Kupiainen-Määttä, O.; Ortega, I. K.; Kurtén, T.; Vehkamäki, H.

    2013-08-01

    The first step in atmospheric new particle formation involves the aggregation of gas phase molecules into small molecular clusters that can grow by colliding with gas molecules and each other. In this work we used first principles quantum chemistry combined with a dynamic model to study the steady-state kinetics of sets of small clusters consisting of sulfuric acid and ammonia or sulfuric acid and dimethylamine molecules. Both sets were studied with and without electrically charged clusters. We show the main clustering pathways in the simulated systems together with the quantum chemical Gibbs free energies of formation of the growing clusters. In the sulfuric acid-ammonia system, the major growth pathways exhibit free energy barriers, whereas in the acid-dimethylamine system the growth occurs mainly via barrierless condensation. When ions are present, charged clusters contribute significantly to the growth in the acid-ammonia system. For dimethylamine the role of ions is minor, except at very low acid concentration, and the growing clusters are electrically neutral.

  2. Stabilization of sulfuric acid dimers by ammonia, methylamine, dimethylamine, and trimethylamine

    NASA Astrophysics Data System (ADS)

    Jen, Coty N.; McMurry, Peter H.; Hanson, David R.

    2014-06-01

    This study experimentally explores how ammonia (NH3), methylamine (MA), dimethylamine (DMA), and trimethylamine (TMA) affect the chemical formation mechanisms of electrically neutral clusters that contain two sulfuric acid molecules (dimers). Dimers may also contain undetectable compounds, such as water or bases, that evaporate upon ionization and sampling. Measurements were conducted using a glass flow reactor which contained a steady flow of humidified nitrogen with sulfuric acid concentrations of 107 to 109 cm-3. A known molar flow rate of a basic gas was injected into the flow reactor. The University of Minnesota Cluster Chemical Ionization Mass Spectrometer was used to measure the resulting sulfuric acid vapor and cluster concentrations. It was found that, for a given concentration of sulfuric acid vapor, the dimer concentration increases with increasing concentration of the basic gas, eventually reaching a plateau. The base concentrations at which the dimer concentrations saturate suggest NH3 < MA < TMA ≲ DMA in forming stabilized sulfuric acid dimers. Two heuristic models for cluster formation by acid-base reactions are developed to interpret the data. The models provide ranges of evaporation rate constants that are consistent with observations and leads to an analytic expression for nucleation rates that is consistent with atmospheric observations.

  3. Structures, Hydration, and Electrical Mobilities of Bisulfate Ion-Sulfuric Acid-Ammonia/Dimethylamine Clusters: A Computational Study.

    PubMed

    Tsona, Narcisse T; Henschel, Henning; Bork, Nicolai; Loukonen, Ville; Vehkamäki, Hanna

    2015-09-17

    Despite the well-established role of small molecular clusters in the very first steps of atmospheric particle formation, their thermochemical data are still not completely available due to limitation of the experimental techniques to treat such small clusters. We have investigated the structures and the thermochemistry of stepwise hydration of clusters containing one bisulfate ion, sulfuric acid, base (ammonia or dimethylamine), and water molecules using quantum chemical methods. We found that water facilitates proton transfer from sulfuric acid or the bisulfate ion to the base or water molecules, and depending on the hydration level, the sulfate ion was formed in most of the base-containing clusters. The calculated hydration energies indicate that water binds more strongly to ammonia-containing clusters than to dimethylamine-containing and base-free clusters, which results in a wider hydrate distribution for ammonia-containing clusters. The electrical mobilities of all clusters were calculated using a particle dynamics model. The results indicate that the effect of humidity is negligible on the electrical mobilities of molecular clusters formed in the very first steps of atmospheric particle formation. The combination of the results of this study with those previously published on the hydration of neutral clusters by our group provides a comprehensive set of thermochemical data on neutral and negatively charged clusters containing sulfuric acid, ammonia, or dimethylamine. PMID:26304742

  4. Structure and Energetics of Nanometer Size Clusters of Sulfuric Acid with Ammonia and Dimethylamine

    SciTech Connect

    Depalma, Joseph W.; Bzdek, Bryan R.; Doren, Doug J.; Johnston, Murray V.

    2012-01-26

    The structures of positively and negatively charged clusters of sulfuric acid with ammonia and/or dimethylamine ((CH{sub 3}){sub 2}NH or DMA) are investigated using a combination of Monte Carlo configuration sampling, semiempirical calculations, and density functional theory (DFT) calculations. Positively charged clusters of the formula [(NH{sub 4}{sup +}){sub x}(HSO{sub 4}{sup -}){sub y}]{sup +}, where x = y + 1, are studied for 1 {le} y {le} 10. These clusters exhibit strong cation-anion interactions, with no contribution to the hydrogen-bonding network from the bisulfate ion protons. A similar hydrogen-bonding network is found for the [(DMAH{sup +}){sub 5}(HSO{sub 4}{sup -}){sub 4}]{sup -} cluster. Negatively charged clusters derived from the reaction of DMA with [(H{sub 2}SO{sub 4}){sub 3}(NH{sub 4}{sup +})(HSO{sub 4}{sup -}){sub 2}]{sup -} are also studied, up to the fully reacted cluster [(DMAH{sup +}){sub 4}(HSO{sub 4}{sup -}){sub 5}]{sup -}. These clusters exhibit anion-anion and ion-molecule interactions in addition to cation-anion interactions. While the hydrogen-bonding network is extensive for both positively and negatively charged clusters, the binding energies of ions and molecules in these clusters are determined mostly by electrostatic interactions. The thermodynamics of amine substitution is explored and compared to experimental thermodynamic and kinetic data. Ammonia binds more strongly than DMA to sulfuric acid due to its greater participation in hydrogen bonding and its ability to form a more compact structure that increases electrostatic attraction between oppositely charged ions. However, the greater gas-phase basicity of DMA is sufficient to overcome the stronger binding of ammonia, making substitution of DMA for ammonia thermodynamically favorable. For small clusters of both polarities, substitutions of surface ammonium ions are facile. As the cluster size increases, an ammonium ion becomes encapsulated in the center of the cluster, making

  5. Computational Study on the Effect of Hydration on New Particle Formation in the Sulfuric Acid/Ammonia and Sulfuric Acid/Dimethylamine Systems.

    PubMed

    Henschel, Henning; Kurtén, Theo; Vehkamäki, Hanna

    2016-03-24

    The formation of new particles through condensation from the gas phase is an important source of atmospheric aerosols. The properties of the electrically neutral clusters formed in the very first steps of the condensation process are, however, not directly observable by experimental means. We present here electronic structure calculations on the hydrates of clusters of three molecules of sulfuric acid and three molecules of ammonia or dimethylamine. On the basis of the results of these new calculations together with previously published material we simulate the influence of hydration on the dynamic processes involved in particle formation. Most strongly affected by hydration and most important as a mediator for the effect on particle formation rates are the evaporation rates of clusters. The results give an estimate of the sensitivity of the atmospheric particle formation rate for humidity. The particle formation rate can change approximately two orders of magnitude in either direction due to hydration; the net effect, however, is highly dependent on the exact conditions. PMID:26918813

  6. Computational Study on the Effect of Hydration on New Particle Formation in the Sulfuric Acid/Ammonia and Sulfuric Acid/Dimethylamine Systems.

    PubMed

    Henschel, Henning; Kurtén, Theo; Vehkamäki, Hanna

    2016-03-24

    The formation of new particles through condensation from the gas phase is an important source of atmospheric aerosols. The properties of the electrically neutral clusters formed in the very first steps of the condensation process are, however, not directly observable by experimental means. We present here electronic structure calculations on the hydrates of clusters of three molecules of sulfuric acid and three molecules of ammonia or dimethylamine. On the basis of the results of these new calculations together with previously published material we simulate the influence of hydration on the dynamic processes involved in particle formation. Most strongly affected by hydration and most important as a mediator for the effect on particle formation rates are the evaporation rates of clusters. The results give an estimate of the sensitivity of the atmospheric particle formation rate for humidity. The particle formation rate can change approximately two orders of magnitude in either direction due to hydration; the net effect, however, is highly dependent on the exact conditions.

  7. Dimethylamine

    Integrated Risk Information System (IRIS)

    Dimethylamine ; CASRN 124 - 40 - 3 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Eff

  8. Oleamidopropyl dimethylamine.

    PubMed

    de Groot, A C

    1989-01-01

    The cationic emulsifier oleamidopropyl dimethylamine has been responsible for many cases of cosmetic sensitisation in The Netherlands. Of 119 patients with proven cosmetic-related allergic contact dermatitis, 13 (11%) were allergic to oleamidopropyl dimethylamine. The clinical data of 12 patients, all sensitised by one particular baby body lotion containing 0.3% of the emulsifier, are presented. The cross-reaction pattern of oleamidopropyl dimethylamine was investigated by patch testing 13 patients allergic to the emulsifier with a series of related amideamine type emulsifiers. Most cross-reactions were observed to ricinoleamidopropyl dimethylamine lactate and tallowamidopropyl dimethylamine (11 patients, 85%). 9 patients (of 12 tested: 75%) reacted to lauramidopropyl dimethylamine and 6 (46%) to myristamidopropyl dimethylamine. It is concluded that the presence of oleamidopropyl dimethylamine in a concentration of 0.3% in stay-on cosmetics, especially when applied to damaged skin and/or the periorbital area, bears a definite risk of the induction and elicitation of contact allergic reactions.

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

    NASA Astrophysics Data System (ADS)

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

    2016-03-01

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

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed Central

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

    2016-01-01

    Abstract Sulfuric acid is widely recognized as a very important substance driving atmospheric aerosol nucleation. Based on quantum chemical calculations it has been suggested that the quantitative detection of gas phase sulfuric acid (H2SO4) by use of Chemical Ionization Mass Spectrometry (CIMS) could be biased in the presence of gas phase amines such as dimethylamine (DMA). An experiment (CLOUD7 campaign) was set up at the CLOUD (Cosmics Leaving OUtdoor Droplets) chamber to investigate the quantitative detection of H2SO4 in the presence of dimethylamine by CIMS at atmospherically relevant concentrations. For the first time in the CLOUD experiment, the monomer sulfuric acid concentration was measured by a CIMS and by two CI‐APi‐TOF (Chemical Ionization‐Atmospheric Pressure interface‐Time Of Flight) mass spectrometers. In addition, neutral sulfuric acid clusters were measured with the CI‐APi‐TOFs. The CLOUD7 measurements show that in the presence of dimethylamine (<5 to 70 pptv) the sulfuric acid monomer measured by the CIMS represents only a fraction of the total H2SO4, contained in the monomer and the clusters that is available for particle growth. Although it was found that the addition of dimethylamine dramatically changes the H2SO4 cluster distribution compared to binary (H2SO4‐H2O) conditions, the CIMS detection efficiency does not seem to depend substantially on whether an individual H2SO4 monomer is clustered with a DMA molecule. The experimental observations are supported by numerical simulations based on A Self‐contained Atmospheric chemistry coDe coupled with a molecular process model (Sulfuric Acid Water NUCleation) operated in the kinetic limit. PMID:27610289

  12. Chemical ionization of clusters formed from sulfuric acid and dimethylamine or diamines

    NASA Astrophysics Data System (ADS)

    Jen, Coty N.; Zhao, Jun; McMurry, Peter H.; Hanson, David R.

    2016-10-01

    Chemical ionization (CI) mass spectrometers are used to study atmospheric nucleation by detecting clusters produced by reactions of sulfuric acid and various basic gases. These instruments typically use nitrate to deprotonate and thus chemically ionize the clusters. In this study, we compare cluster concentrations measured using either nitrate or acetate. Clusters were formed in a flow reactor from vapors of sulfuric acid and dimethylamine, ethylene diamine, tetramethylethylene diamine, or butanediamine (also known as putrescine). These comparisons show that nitrate is unable to chemically ionize clusters with high base content. In addition, we vary the ion-molecule reaction time to probe ion processes which include proton-transfer, ion-molecule clustering, and decomposition of ions. Ion decomposition upon deprotonation by acetate/nitrate was observed. More studies are needed to quantify to what extent ion decomposition affects observed cluster content and concentrations, especially those chemically ionized with acetate since it deprotonates more types of clusters than nitrate.Model calculations of the neutral and ion cluster formation pathways are also presented to better identify the cluster types that are not efficiently deprotonated by nitrate. Comparison of model and measured clusters indicate that sulfuric acid dimers with two diamines and sulfuric acid trimers with two or more base molecules are not efficiently chemical ionized by nitrate. We conclude that acetate CI provides better information on cluster abundancies and their base content than nitrate CI.

  13. Neutral molecular cluster formation of sulfuric acid-dimethylamine observed in real time under atmospheric conditions.

    PubMed

    Kürten, Andreas; Jokinen, Tuija; Simon, Mario; Sipilä, Mikko; Sarnela, Nina; Junninen, Heikki; Adamov, Alexey; Almeida, João; Amorim, Antonio; Bianchi, Federico; Breitenlechner, Martin; Dommen, Josef; Donahue, Neil M; Duplissy, Jonathan; Ehrhart, Sebastian; Flagan, Richard C; Franchin, Alessandro; Hakala, Jani; Hansel, Armin; Heinritzi, Martin; Hutterli, Manuel; Kangasluoma, Juha; Kirkby, Jasper; Laaksonen, Ari; Lehtipalo, Katrianne; Leiminger, Markus; Makhmutov, Vladimir; Mathot, Serge; Onnela, Antti; Petäjä, Tuukka; Praplan, Arnaud P; Riccobono, Francesco; Rissanen, Matti P; Rondo, Linda; Schobesberger, Siegfried; Seinfeld, John H; Steiner, Gerhard; Tomé, António; Tröstl, Jasmin; Winkler, Paul M; Williamson, Christina; Wimmer, Daniela; Ye, Penglin; Baltensperger, Urs; Carslaw, Kenneth S; Kulmala, Markku; Worsnop, Douglas R; Curtius, Joachim

    2014-10-21

    For atmospheric sulfuric acid (SA) concentrations the presence of dimethylamine (DMA) at mixing ratios of several parts per trillion by volume can explain observed boundary layer new particle formation rates. However, the concentration and molecular composition of the neutral (uncharged) clusters have not been reported so far due to the lack of suitable instrumentation. Here we report on experiments from the Cosmics Leaving Outdoor Droplets chamber at the European Organization for Nuclear Research revealing the formation of neutral particles containing up to 14 SA and 16 DMA molecules, corresponding to a mobility diameter of about 2 nm, under atmospherically relevant conditions. These measurements bridge the gap between the molecular and particle perspectives of nucleation, revealing the fundamental processes involved in particle formation and growth. The neutral clusters are found to form at or close to the kinetic limit where particle formation is limited only by the collision rate of SA molecules. Even though the neutral particles are stable against evaporation from the SA dimer onward, the formation rates of particles at 1.7-nm size, which contain about 10 SA molecules, are up to 4 orders of magnitude smaller compared with those of the dimer due to coagulation and wall loss of particles before they reach 1.7 nm in diameter. This demonstrates that neither the atmospheric particle formation rate nor its dependence on SA can simply be interpreted in terms of cluster evaporation or the molecular composition of a critical nucleus.

  14. Interaction between the silyl and silylen centres in the deposits prepared by pulsed laser ablation of silicon monoxide and ammonia, methylamine and dimethylamine

    NASA Astrophysics Data System (ADS)

    Dřínek, V.; Vacek, K.; Yuzhakov, G.; Bastl, Z.

    2005-10-01

    Silicon suboxide films were prepared by TEA CO2 pulsed laser ablation (PLA) of the silicon monoxide target in the Kr atmosphere. The deposits were examined by means of Fourier transformed infrared spectroscopy (FTIR), electron paramagnetic resonance spectroscopy (EPR) and X-ray photoelectron spectroscopy (XPS). The generated point defects in the films mostly silyl ≡Si· (E’ center) and silylen =Si: were allowed to react with the gaseous ammonia NH3, methylamine MeNH2 and dimethylamine Me2NH after the ablation. As a result, the functional groups ≡SiNHxMey (x+y=2) were formed. The reactivity of the deposits are due to silyl ≡Si· and silylen =Si: radicals as deduced by comparison of the initial concentration of the silyl radicals (5.3 9.8×1019 /g, EPR) and the newly formed -(Si)NH bonds (3.6×1019 /g, FTIR). The observed absorption bands ν(SiH) at 2223, 2214 and 2220 cm-1 could be assigned to =(O2)Si(H)NH2, =(O2)Si(H)NHMe and =(O2)Si(H)NMe2 species. The singlet line in EPR spectrum of the native deposit before exposition is due to the silyl radical with free valence on the silicon backbonded via oxygen and another silicon atom. After exposition either to NH3 or MeNH2 the silyl concentration rapidly decreased to several % of its original value.

  15. Ion mobility spectrometry-mass spectrometry examination of the structures, stabilities, and extents of hydration of dimethylamine-sulfuric acid clusters.

    PubMed

    Thomas, Jikku M; He, Siqin; Larriba-Andaluz, Carlos; DePalma, Joseph W; Johnston, Murray V; Hogan, Christopher J

    2016-08-17

    We applied an atmospheric pressure differential mobility analyzer (DMA) coupled to a time-of-flight mass spectrometer to examine the stability, mass-mobility relationship, and extent of hydration of dimethylamine-sulfuric acid cluster ions, which are of relevance to nucleation in ambient air. Cluster ions were generated by electrospray ionization and were of the form: [H((CH3)2NH)x(H2SO4)y](+) and [(HSO4)((CH3)2NH)x(H2SO4)y](-), where 4 ≤ x ≤ 8, and 5 ≤ y ≤ 12. Under dry conditions, we find that positively charged cluster ions dissociated via loss of both multiple dimethylamine and sulfuric acid molecules after mobility analysis but prior to mass analysis, and few parent ions were detected in the mass spectrometer. Dissociation also occurred for negative ions, but to a lesser extent than for positive ions for the same mass spectrometer inlet conditions. Under humidified conditions (relative humidities up to 30% in the DMA), positively charged cluster ion dissociation in the mass spectrometer inlet was mitigated and occurred primarily by H2SO4 loss from ions containing excess acid molecules. DMA measurements were used to infer collision cross sections (CCSs) for all identifiable cluster ions. Stokes-Millikan equation and diffuse/inelastic gas molecule scattering predicted CCSs overestimate measured CCSs by more than 15%, while elastic-specular collision model predictions are in good agreement with measurements. Finally, cluster ion hydration was examined by monitoring changes in CCSs with increasing relative humidity. All examined cluster ions showed a modest amount of water molecule adsorption, with percentage increases in CCS smaller than 10%. The extent of hydration correlates directly with cluster ion acidity for positive ions. PMID:27485283

  16. Contact allergy to oleamidopropyl dimethylamine.

    PubMed

    de Groot, A G; Liem, D H

    1984-11-01

    Contact allergy to the cationic emulsifier oleamidopropyl dimethylamine was demonstrated in 3 patients. In every case the emulsifier was present in a particular brand of body lotion. Patch test concentrations of 0.1% and 0.5% in water are proposed; slightly higher concentrations may induce irritant responses. Although these are the first documented cases of contact allergy to oleamidopropyl dimethylamine, it is argued that hypersensitivity to this compound may not be rare.

  17. Statistical modeling of ammonia absorption in an acid spray scrubber

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The use of acid spray wet scrubbers for recovering ammonia (NH3) emissions is promising due to its high NH3 removal efficiency, simplicity in design, and minimal pressure drop contribution on fans. An experimental study was conducted to evaluate the performance of a lab-optimised acid spray scrubber...

  18. Cinnamic acid production using Streptomyces lividans expressing phenylalanine ammonia lyase.

    PubMed

    Noda, Shuhei; Miyazaki, Takaya; Miyoshi, Takanori; Miyake, Michiru; Okai, Naoko; Tanaka, Tsutomu; Ogino, Chiaki; Kondo, Akihiko

    2011-05-01

    Cinnamic acid production was demonstrated using Streptomyces as a host. A gene encoding phenylalanine ammonia lyase (PAL) from Streptomyces maritimus was introduced into Streptomyces lividans, and its expression was confirmed by Western blot analysis. After 4 days cultivation using glucose as carbon source, the maximal level of cinnamic acid reached 210 mg/L. When glycerol (30 g/L) was used as carbon source, the maximal level of produced cinnamic acid reached 450 mg/L. In addition, using raw starch, xylose or xylan as carbon source, the maximal level of cinnamic acid reached 460, 300, and 130 mg/L, respectively. We demonstrated that S. lividans has great potential to produce cinnamic acid as well as other aromatic compounds.

  19. Synthesis of amino acids by the heating of formaldehyde and ammonia.

    PubMed

    Fox, S W; Windsor, C R

    1970-11-27

    The heating of formaldehyde and ammonia yields a product that, on hydrolysis, is converted into seven amino acids: aspartic acid, glutamic acid, serine, proline, valine, glycine, and alanine. Glycine is the predominant amino acid. Inasmuch as formaldehyde and ammonia have been identified as compounds in galactic clouds, these experimental results are interpreted in a cosmochemical and geochemical context.

  20. 21 CFR 173.60 - Dimethylamine-epichlorohydrin copolymer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... copolymerization of dimethylamine and epichlorohydrin in which not more than 5 mole-percent of dimethylamine may be replaced by an equimolar amount of ethylenediamine, and in which the mole ratio of total amine...

  1. Ammonia

    Integrated Risk Information System (IRIS)

    Ammonia ; CASRN 7664 - 41 - 7 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effects

  2. A microwave study of the ammonia-nitric acid complex

    SciTech Connect

    Ott, M.E.; Leopold, K.R.

    1999-03-11

    Microwave spectra of H{sub 3}{sup 14}N-H{sup 14}NO{sub 3}, H{sub 3}{sup 15}N-H{sup 14}NO{sub 3}, H{sub 3}{sup 14}N-H{sup 15}NO{sub 3}, and H{sub 3}{sup 14}N-D{sup 14}NO{sub 3} have been obtained by Fourier transform spectroscopy in a supersonic jet. The spectra are consistent with a hydrogen-bonded structure having a planar arrangement of the heavy atom frame and a linear or near-linear hydrogen bond involving the HNO{sub 3} proton and the lone pair on the ammonia. The hydrogen bond length obtained from the rotational constants is 1.736(63) {angstrom} and the nitrogen-nitrogen separation is 3.344(12) {angstrom}. The NO single bond of the nitric acid and the C{sub 3} axis of the NH{sub 3} form angles of 54(4){degree} and 21(3){degree}, respectively, with the line joining the centers of mass of the monomers. The hydrogen bond length is significantly shorter than that observed in related complexes such as H{sub 3}N-HCl and H{sub 3}N-HBr, indicating a particularly strong interaction between ammonia and nitric acid.

  3. Amine Reactivity with Nanoclusters of Sulfuric Acid and Ammonia

    NASA Astrophysics Data System (ADS)

    Johnston, M. V.; Bzdek, B. R.; DePalma, J.

    2011-12-01

    Alkyl amines have emerged as key species in new particle formation and growth. This interest is reinforced by ambient measurements of amines (e.g. Smith et al., 2010) and enhanced levels of nitrogen (e.g. Bzdek et al., 2011) during growth of newly formed particles. An important mechanism of amine uptake is aminium salt formation, either by substituting for ammonium ions that already exist in the particle or by opening new channels for salt formation that are not favorable with ammonia. This presentation will focus on recent experimental and computational work in our group to study amine uptake into charged nanoclusters of sulfuric acid and ammonia. In the experimental work, clusters are produced by electrospray of an ammonium sulfate solution and then drawn into a Fourier transform ion cyclotron resonance mass spectrometer where a specific cluster is isolated and exposed to amine vapor. We find that amine reactivity is dependent on the size, composition and charge of the isolated cluster. For small clusters of either polarity, all ammonium ions reside on the surface and amine substitution occurs with near unit reaction probability. As the cluster size increases, an ammonium ion can be encapsulated in the center of the cluster, which provides a steric hindrance to amine substitution. Negatively charged clusters are more likely to be acidic than positively charged clusters. For acidic clusters, incoming amine molecules first substitute for preexisting ammonium ions and then add to the cluster until a "neutralized" aminium bisulfate composition is reached. Computational studies of these clusters provide fundamental insight into the thermodynamics and kinetics of amine uptake.

  4. Effect of ascorbic acid on the properties of ammonia caramel colorant additives and acrylamide formation.

    PubMed

    Chen, Hongxing; Gu, Zhengbiao

    2014-09-01

    Ammonia caramels are among the most widely used colorant additives in the food industry. They are commonly prepared through the Maillard reaction and caramelization of mixtures of reducing sugars with ammonia or ammonium salts. Antioxidants are known to inhibit acrylamide formation during the Maillard reaction, and they may affect the properties of the ammonia caramel products. Thus, the objective of this study was to investigate the effect of the antioxidant ascorbic acid on the properties of ammonia caramel. A mixture of glucose and ammonia was allowed to react at 120 °C for 60 min in the presence of ascorbic acid at final concentrations of 0 to 0.08 M. The ammonia caramels obtained from these reactions were all positively charged. As the concentration of ascorbic acid increased, the color intensity of the ammonia caramel showed a decreasing trend, while the intensity of the fluorescence and total amount of pyrazines in the volatiles showed a tendency to increase. The addition of ascorbic acid did not result in obvious changes in the UV-visible spectra of the ammonia caramels and the types of pyrazines in the volatiles were also unchanged. It is noteworthy that the addition of 0.02 to 0.08 M ascorbic acid did reduce the formation of the by-product acrylamide, a harmful substance in food. When the concentration of ascorbic acid added reached 0.04 M, the content of acrylamide in the ammonia caramel was 20.53 μg/L, which was approximately 44% lower than that without ascorbic acid. As a result, ascorbic acid can be considered to improve the quality and safety of ammonia caramels.

  5. The relationship between airborne acidity and ammonia in indoor environments.

    PubMed

    Suh, H H; Koutrakis, P; Spengler, J D

    1994-01-01

    Indoor acid aerosol, nitric acid (HNO3), and ammonia (NH3) concentrations were measured in 47 homes in State College, Pennsylvania, during the summer of 1991. From each home, 12-hour indoor, 12- and 24-hour outdoor, and 12-hour air exchange samples were collected continuously over a 5-day period. Additionally, questionnaires were administered daily by field technicians to obtain information on house occupant number, ventilation, gas stove use, pets, and other housing characteristics. In this paper, we discuss the relationship between NH3 and corresponding concentrations of aerosol strong acidity (H+) and HNO3 inside these homes. As part of this analysis, we also examined indoor/outdoor concentration relationships and identified housing factors that may influence indoor levels. In State College, indoor NH3 concentrations were higher than corresponding outdoor levels, with air conditioner use, air exchange rates, and occupant number identified as important determinants of indoor levels. Indoor concentrations of both H+ and HNO3 were substantially lower than outdoor levels, as homes with air exchange rates less than one exchange per hour were found to have essentially no acid indoors. These low H+ and HNO3 levels likely resulted from their reaction with indoor NH3 and with indoor surfaces. Indoor NH3 concentrations were higher than outdoor levels, indicating the presence of indoor NH3 sources; however, correlations between indoor NH3 and both pets and occupants, its primary indoor sources, were weak and negative, respectively. Mass balance models that included an NH3 neutralization term were found to predict indoor H+ concentrations reasonably well, representing a substantial improvement over outdoor concentrations alone. The accumulation of NH3 indoors was found to be the primary determinant of indoor H+ and HNO3 levels.

  6. Branched-chain amino acids increase arterial blood ammonia in spite of enhanced intrinsic muscle ammonia metabolism in patients with cirrhosis and healthy subjects.

    PubMed

    Dam, Gitte; Keiding, Susanne; Munk, Ole Lajord; Ott, Peter; Buhl, Mads; Vilstrup, Hendrik; Bak, Lasse Kristoffer; Waagepetersen, Helle Sønderby; Schousboe, Arne; Møller, Niels; Sørensen, Michael

    2011-08-01

    Branched-chain amino acids (BCAA) are used in attempts to reduce blood ammonia in patients with cirrhosis and intermittent hepatic encephalopathy based on the hypothesis that BCAA stimulate muscle ammonia detoxification. We studied the effects of an oral dose of BCAA on the skeletal muscle metabolism of ammonia and amino acids in 14 patients with cirrhosis and in 7 healthy subjects by combining [(13)N]ammonia positron emission tomography (PET) of the thigh muscle with measurements of blood flow and arteriovenous (A-V) concentrations of ammonia and amino acids. PET was used to measure the metabolism of blood-supplied ammonia and the A-V measurements were used to measure the total ammonia metabolism across the thigh muscle. After intake of BCAA, blood ammonia increased more than 30% in both groups of subjects (both P < 0.05). Muscle clearance of blood-supplied ammonia (PET) was unaffected (P = 0.75), but the metabolic removal rate (PET) increased significantly because of increased blood ammonia in both groups (all P < 0.05). The total ammonia clearance across the leg muscle (A-V) increased by more than 50% in both groups, and the flux (A-V) of ammonia increased by more than 45% (all P < 0.05). BCAA intake led to a massive glutamine release from the muscle (cirrhotic patients, P < 0.05; healthy subjects, P = 0.12). In conclusion, BCAA enhanced the intrinsic muscle metabolism of ammonia but not the metabolism of blood-supplied ammonia in both the patients with cirrhosis and in the healthy subjects.

  7. Thaumarchaeal ammonia oxidation in an acidic forest peat soil is not influenced by ammonium amendment.

    PubMed

    Stopnisek, Nejc; Gubry-Rangin, Cécile; Höfferle, Spela; Nicol, Graeme W; Mandic-Mulec, Ines; Prosser, James I

    2010-11-01

    Both bacteria and thaumarchaea contribute to ammonia oxidation, the first step in nitrification. The abundance of putative ammonia oxidizers is estimated by quantification of the functional gene amoA, which encodes ammonia monooxygenase subunit A. In soil, thaumarchaeal amoA genes often outnumber the equivalent bacterial genes. Ecophysiological studies indicate that thaumarchaeal ammonia oxidizers may have a selective advantage at low ammonia concentrations, with potential adaptation to soils in which mineralization is the major source of ammonia. To test this hypothesis, thaumarchaeal and bacterial ammonia oxidizers were investigated during nitrification in microcosms containing an organic, acidic forest peat soil (pH 4.1) with a low ammonium concentration but high potential for ammonia release during mineralization. Net nitrification rates were high but were not influenced by addition of ammonium. Bacterial amoA genes could not be detected, presumably because of low abundance of bacterial ammonia oxidizers. Phylogenetic analysis of thaumarchaeal 16S rRNA gene sequences indicated that dominant populations belonged to group 1.1c, 1.3, and "deep peat" lineages, while known amo-containing lineages (groups 1.1a and 1.1b) comprised only a small proportion of the total community. Growth of thaumarchaeal ammonia oxidizers was indicated by increased abundance of amoA genes during nitrification but was unaffected by addition of ammonium. Similarly, denaturing gradient gel electrophoresis analysis of amoA gene transcripts demonstrated small temporal changes in thaumarchaeal ammonia oxidizer communities but no effect of ammonium amendment. Thaumarchaea therefore appeared to dominate ammonia oxidation in this soil and oxidized ammonia arising from mineralization of organic matter rather than added inorganic nitrogen.

  8. Pilot-scale field study for ammonia removal from lagoon biogas using an acid wet scrubber.

    PubMed

    Lin, Hongjian; Wu, Xiao; Miller, Curtis; Zhu, Jun; Hadlocon, Lara Jane; Manuzon, Roderick; Zhao, Lingying

    2014-01-01

    The anaerobic activities in swine slurry storage and treatment generate biogas containing gaseous ammonia component which is a chemical agent that can cause adverse environmental impacts when released to the atmosphere. The aim of this pilot plant study was to remove ammonia from biogas generated in a covered lagoon, using a sulfuric acid wet scrubber. The data showed that, on average, the biogas contained 43.7 ppm of ammonia and its concentration was found to be exponentially related to the air temperature inside the lagoon. When the air temperature rose to 35°C and the biogas ammonia concentration reached 90 ppm, the mass transfer of ammonia/ammonium from the deeper liquid body to the interface between the air and liquid became a limiting factor. The biogas velocity was critical in affecting ammonia removal efficiency of the wet scrubber. A biogas flow velocity of 8 to 12 mm s(-1) was recommended to achieve a removal efficiency of greater than 60%. Stepwise regression revealed that the biogas velocity and air temperature, not the inlet ammonia concentration in biogas, affected the ammonia removal efficiency. Overall, when 73 g L(-1) (or 0.75 M) sulfuric acid solution was used as the scrubber solution, removal efficiencies varied from 0% to 100% with an average of 55% over a 40-d measurement period. Mass balance calculation based on ammonium-nitrogen concentration in final scrubber liquid showed that about 21.3 g of ammonia was collected from a total volume of 1169 m(3) of biogas, while the scrubber solution should still maintain its ammonia absorbing ability until its concentration reaches up to 1 M. These results showed promising use of sulfuric acid wet scrubber for ammonia removal in the digester biogas.

  9. Intercalation studies of zinc hydroxide chloride: Ammonia and amino acids

    SciTech Connect

    Arizaga, Gregorio Guadalupe Carbajal

    2012-01-15

    Zinc hydroxide chloride (ZHC) is a layered hydroxide salt with formula Zn{sub 5}(OH){sub 8}Cl{sub 2}{center_dot}2H{sub 2}O. It was tested as intercalation matrix for the first time and results were compared with intercalation products of the well-known zinc hydroxide nitrate and a Zn/Al layered double hydroxide. Ammonia was intercalated into ZHC, while no significant intercalation occurred in ZHN. Aspartic acid intercalation was only achieved by co-precipitation at pH=10 with ZHC and pH=8 with zinc hydroxide nitrate. Higher pH resistance in ZHC favored total deprotonation of both carboxylic groups of the Asp molecule. ZHC conferred more thermal protection against Asp combustion presenting exothermic peaks even at 452 Degree-Sign C while the exothermic event in ZHN was 366 Degree-Sign C and in the LDH at 276 Degree-Sign C. - Graphical abstract: The zinc hydroxide chloride (ZHC) with formula Zn{sub 5}(OH){sub 8}Cl{sub 2}{center_dot}2H{sub 2}O was tested as intercalation matrix. In comparison with the well-known zinc hydroxide nitrate (ZHN) and layered double hydroxides (LDH), ZHC was the best matrix for thermal protection of Asp combustion, presenting exothermic peaks even at 452 Degree-Sign C, while the highest exothermic event in ZHN was at 366 Degree-Sign C, and in the LDH it was at 276 Degree-Sign C. Highlights: Black-Right-Pointing-Pointer Zinc hydroxide chloride (ZHC) was tested as intercalation matrix for the first time. Black-Right-Pointing-Pointer ZHC has higher chemical and thermal stability than zinc hydroxide nitrate and LDH. Black-Right-Pointing-Pointer NH{sub 3} molecules can be intercalated into ZHC. Black-Right-Pointing-Pointer The amino group of amino acids limits the intercalation by ion-exchange.

  10. Process for removal of ammonia and acid gases from contaminated waters

    DOEpatents

    King, C. Judson; MacKenzie, Patricia D.

    1985-01-01

    Contaminating basic gases, i.e., ammonia, and acid gases, e.g., carbon dioxide, are removed from process waters or waste waters in a combined extraction and stripping process. Ammonia in the form of ammonium ion is extracted by an immiscible organic phase comprising a liquid cation exchange component, especially an organic phosphoric acid derivative, and preferably di-2-ethyl hexyl phosphoric acid, dissolved in an alkyl hydrocarbon, aryl hydrocarbon, higher alcohol, oxygenated hydrocarbon, halogenated hydrocarbon, and mixtures thereof. Concurrently, the acidic gaseous contaminants are stripped from the process or waste waters by stripping with steam, air, nitrogen, or the like. The liquid cation exchange component has the ammonia stripped therefrom by heating, and the component may be recycled to extract additional amounts of ammonia.

  11. Process for removal of ammonia and acid gases from contaminated waters

    DOEpatents

    King, C.J.; Mackenzie, P.D.

    1982-09-03

    Contaminating basic gases, i.e., ammonia and acid gases, e.g., carbon dioxide, are removed from process waters or waste waters in a combined extraction and stripping process. Ammonia in the form of ammonium ion is extracted by an immiscible organic phase comprising a liquid cation exchange component, especially an organic phosphoric acid derivative, and preferably di-2-ethyl hexyl phosphoric acid, dissolved in an alkyl hydrocarbon, aryl hydrocarbon, higher alcohol, oxygenated hydrocarbon, halogenated hydrocarbon, and mixtures thereof. Concurrently, the acidic gaseous contaminants are stripped from the process or waste waters by stripping with stream, air, nitrogen, or the like. The liquid cation exchange component has the ammonia stripped therefrom by heating, and the component may be recycled to extract additional amounts of ammonia.

  12. Preparation of unnatural amino acids with ammonia-lyases and 2,3-aminomutases.

    PubMed

    Poppe, László; Paizs, Csaba; Kovács, Klaudia; Irimie, Florin-Dan; Vértessy, Beáta

    2012-01-01

    Ammonia-lyases catalyze a wide range of processes leading to α,β-unsaturated compounds by elimination of ammonia. In this chapter, ammonia-lyases are reviewed with major emphasis on their synthetic applications in stereoselective preparation of unnatural amino acids. Besides the synthesis of various unnatural α-amino acids with the aid of phenylalanine ammonia-lyases (PALs) utilizing the 3,5-dihydro-5-methylidene-4H-imidazol-4-one (MIO) prosthetic groups, the biotransformations leading to various unnatural β-amino acids with phenylalanine 2,3-aminomutases using the same catalytic MIO prosthetic group are discussed. Cloning, production, purification, and biotransformation protocols for PAL are described in detail.

  13. Branched-chain amino acids and muscle ammonia detoxification in cirrhosis.

    PubMed

    Dam, Gitte; Ott, Peter; Aagaard, Niels Kristian; Vilstrup, Hendrik

    2013-06-01

    Branched-chain amino acids (BCAA) are used as a therapeutic nutritional supplement in patients with cirrhosis and hepatic encephalopathy (HE). During liver disease, the decreased capacity for urea synthesis and porto-systemic shunting reduce the hepatic clearance of ammonia and skeletal muscle may become the main alternative organ for ammonia detoxification. We here summarize current knowledge of muscle BCAA and ammonia metabolism with a focus on liver cirrhosis and HE. Plasma levels of BCAA are lower and muscle uptake of BCAA seems to be higher in patients with cirrhosis and hyperammonemia. BCAA metabolism may improve muscle net ammonia removal by supplying carbon skeletons for formation of alfa-ketoglutarate that combines with two ammonia molecules to become glutamine. An oral dose of BCAA enhances muscle ammonia metabolism but also transiently increases the arterial ammonia concentration, likely due to extramuscular metabolism of glutamine. We, therefore, speculate that the beneficial effect of long term intake of BCAA on HE demonstrated in clinical studies may be related to an improved muscle mass and nutritional status rather than to an ammonia lowering effect of BCAA themselves.

  14. Interaction of Gas Phase Oxalic Acid with Ammonia and its Atmospheric Implications

    SciTech Connect

    Peng, Xiu-Qiu; Liu, Yi-Rong; Huang, Teng; Jiang, Shuai; Huang, Wei

    2015-04-14

    Oxalic acid is believed to play an important role in the formation and growth of atmospheric organic aerosols. However, as a common organic acid, the understanding of the larger clusters formed by gas phase oxalic acid with multiple ammonia molecules is incomplete. In this work, the structural characteristics and thermodynamics of oxalic acid clusters with up to six ammonia molecules have been investigated at the PW91PW91/6-311++G(3df,3pd) level of theory. We found that oxalic acid forms relatively stable clusters with ammonia molecules, and that ionization events play a key role. The analyses of the thermodynamics and atmospheric relevance indicate that the heterodimer (H2C2O4)(NH3) shows an obvious relative concentration in the atmosphere, and thus likely participates in new particle formation. However, with increasing number of ammonia molecules, the concentration of clusters decreases gradually. Additionally, clusters of oxalic acid with ammonia molecules are predicted to form favorably in low temperature conditions and show high Rayleigh scattering intensities.

  15. Renal Regulation of Acid-Base Balance: Ammonia Excretion.

    ERIC Educational Resources Information Center

    Tanner, George A.

    1984-01-01

    Describes an experiment which demonstrates changes in ammonia excretion and urine pH that occur in response to metabolic acidosis (induced by ammonium chloride ingestion) or metabolic alkalosis (produced by sodium bicarbonate ingestion). List of materials needed and background information are included. Typical results are provided and discussed.…

  16. Immobilization of enzyme on dimethyl-aminated nylon gels

    SciTech Connect

    Miyama, H.; Kawate, M.; Nosaka, Y.

    1985-10-01

    Miyama and co-workers have reported that dimethyl-aminated Nylon is a good material for the immobilization of enzyme after being quaternized. Also, they found a good correlation between the apparent Michaelis constant of the immobilized enzyme and the diffusion constant of the substrate in the matrix, and that between activity of the immobilized enzyme and interfacial free energy of the matrix. In their experiments, Nylon films of low degree of dimethylamination were used. In the present study, dimethylaminated Nylon of high degree of dimethylamination was quaternized by cationic oligomers having two functional groups. Thus, hydrogels were obtained, where the degree of cross-linking and the density of cation could be varied by changing the feeding amount and the length of cross-linking oligomers. These gels were then tested for the immobilization of urease and glucose oxidase. 9 references.

  17. Is there in vivo evidence for amino acid shuttles carrying ammonia from neurons to astrocytes?

    PubMed

    Rothman, Douglas L; De Feyter, Henk M; Maciejewski, Paul K; Behar, Kevin L

    2012-11-01

    The high in vivo flux of the glutamate/glutamine cycle puts a strong demand on the return of ammonia released by phosphate activated glutaminase from the neurons to the astrocytes in order to maintain nitrogen balance. In this paper we review several amino acid shuttles that have been proposed for balancing the nitrogen flows between neurons and astrocytes in the glutamate/glutamine cycle. All of these cycles depend on the directionality of glutamate dehydrogenase, catalyzing reductive glutamate synthesis (forward reaction) in the neuron in order to capture the ammonia released by phosphate activated glutaminase, while catalyzing oxidative deamination of glutamate (reverse reaction) in the astrocytes to release ammonia for glutamine synthesis. Reanalysis of results from in vivo experiments using (13)N and (15)N labeled ammonia and (15)N leucine in rats suggests that the maximum flux of the alanine/lactate or branched chain amino acid/branched chain amino acid transaminase shuttles between neurons and astrocytes are approximately 3-5 times lower than would be required to account for the ammonia transfer from neurons to astrocytes needed for glutamine synthesis (amide nitrogen) to sustain the glutamate/glutamine cycle. However, in the rat brain both the total ammonia fixation rate by glutamate dehydrogenase and the total branched chain amino acid transaminase activity are sufficient to support a branched chain amino acid/branched chain keto acid shuttle, as proposed by Hutson and coworkers, which would support the de novo synthesis of glutamine in the astrocyte to replace the ~20 % of neurotransmitter glutamate that is oxidized. A higher fraction of the nitrogen needs of total glutamate neurotransmitter cycling could be supported by hybrid cycles in which glutamate and tricarboxylic acid cycle intermediates act as a nitrogen shuttle. A limitation of all in vivo studies in animals conducted to date is that none have shown transfer of nitrogen for glutamine amide

  18. Novel Regenerated Solvent Extraction Processes for the Recovery of Carboxylic Acids or Ammonia from Aqueous Solutions Part II. Recovery of Ammonia from Sour Waters

    SciTech Connect

    Poole, L.J.; King, C.J.

    1990-03-01

    Two novel regenerated solvent extraction processes are examined. The first process has the potential to reduce the energy costs inherent in the recovery of low-volatility carboxylic acids from dilute aqueous solutions. The second process has the potential for reducing the energy costs required for separate recovery of ammonia and acid gases (e.g. CO{sub 2} and H{sub 2}S) from industrial sour waters. The recovery of carboxylic acids from dilute aqueous solution can be achieved by extraction with tertiary amines. An approach for regeneration and product recovery from such extracts is to back-extract the carboxylic acid with a water-soluble, volatile tertiary amine, such as trimethylamine. The resulting trimethylammonium carboxylate solution can be concentrated and thermally decomposed, yielding the product acid and the volatile amine for recycle. Experimental work was performed with lactic acid, SUCCiOlC acid, and fumaric acid. Equilibrium data show near-stoichiometric recovery of the carboxylic acids from an organic solution of Alamine 336 into aqueous solutions of trimethylamine. For fumaric and succinic acids, partial evaporation of the aqueous back extract decomposes the carboxylate and yields the acid product in crystalline form. The decomposition of aqueous solutions of trimethylammonium lactates was not carried out to completion, due to the high water solubility of lactic acid and the tendency of the acid to self-associate. The separate recovery of ammonia and acid gases from sour waters can be achieved by combining steam-stripping of the acid gases with simultaneous removal of ammonia by extraction with a liquid cation exchanger. The use of di-2,4,4-trimethylpentyl phosphinic acid as the liquid cation exchanger is explored in this work. Batch extraction experiments were carried out to measure the equilibrium distribution ratio of ammonia between an aqueous buffer solution and an organic solution of the phosphinic acid (0.2N) in Norpar 12. The concentration

  19. Direct microwave-assisted amino acid synthesis by reaction of succinic acid and ammonia in the presence of magnetite

    NASA Astrophysics Data System (ADS)

    Jiang, Nan; Liu, Dandan; Shi, Weiguang; Hua, Yingjie; Wang, Chongtai; Liu, Xiaoyang

    2013-10-01

    Since the discovery of submarine hot vents in the late 1970s, it has been postulated that submarine hydrothermal environments would be suitable for emergence of life on Earth. To simulate warm spring conditions, we designed a series of microwave-assisted amino acid synthesis involving direct reactions between succinic acid and ammonia in the presence of the magnetite catalyst. These reactions which generated aspartic acid and glycine were carried out under mild temperatures and pressures (90-180 °C, 4-19 bar). We studied this specific reaction inasmuch as succinic acid and ammonia were traditionally identified as prebiotic compounds in primitive deep-sea hydrothermal systems on Earth. The experimental results were discussed in both biochemical and geochemical context to offer a possible route for abiotic amino acid synthesis. With extremely diluted starting materials (0.002 M carboxylic acid and 0.002 M ammonia) and catalyst loading, an obvious temperature dependency was observed in both cases [neither product was detected at 90 °C in comparison with 21.08 μmol L-1 (aspartic acid) and 70.25 umol L-1 (glycine) in 180 °C]. However, an opposite trend presented for reaction time factor, namely a positive correlation for glycine, but a negative one for aspartic acid.

  20. Isotopic analyses of nitrogenous compounds from the Murchison meteorite: ammonia, amines, amino acids, and polar hydrocarbons

    NASA Technical Reports Server (NTRS)

    Pizzarello, S.; Feng, X.; Epstein, S.; Cronin, J. R.

    1994-01-01

    The combined volatile bases (ammonia, aliphatic amines, and possibly other bases), ammonia, amino acids, and polar hydrocarbons were prepared from the Murchison meteorite for isotopic analyses. The volatile bases were obtained by cryogenic transfer after acid-hydrolysis of a hot-water extract and analyzed by combined gas chromatography-mass spectrometry of pentafluoropropionyl derivatives. The aliphatic amines present in this preparation comprise a mixture that includes both primary and secondary isomers through C5 at a total concentration of > or = 100 nmoles g-1. As commonly observed for meteoritic organic compounds, almost all isomers through C5 are present, and the concentrations within homologous series decrease with increasing chain length. Ammonia was chromatographically separated from the other volatile bases and found at a concentration of 1.1-1.3 micromoles g-1 meteorite. The ammonia analyzed includes contributions from ammonium salts and the hydrolysis of extractable organic compounds, e.g., carboxamides. Stable isotope analyses showed the volatile bases to be substantially enriched in the heavier isotopes, relative to comparable terrestrial compounds delta D < or = +1221%; delta 13C = +22%; delta 15N = +93%). Ammonia, per se, was found to have a somewhat lower delta 15N value (+69%) than the total volatile bases; consequently, a higher delta 15N (>93%) can be inferred for the other bases, which include the amines. Solvent-extractable polar hydrocarbons obtained separately were found to be enriched in 15N (delta 15N = +104%). Total amino acids, prepared from a hydrolyzed hot-water extract by cation exchange chromatography, gave a delta 15N of +94%, a value in good agreement with that obtained previously. Nitrogen isotopic data are also given for amino acid fractions separated chromatographically. The delta 15N values of the Murchison soluble organic compounds analyzed to date fall within a rather narrow range (delta 15N = +94 +/- 8%), an observation

  1. Phenylalanine ammonia lyase catalyzed synthesis of amino acids by an MIO-cofactor independent pathway.

    PubMed

    Lovelock, Sarah L; Lloyd, Richard C; Turner, Nicholas J

    2014-04-25

    Phenylalanine ammonia lyases (PALs) belong to a family of 4-methylideneimidazole-5-one (MIO) cofactor dependent enzymes which are responsible for the conversion of L-phenylalanine into trans-cinnamic acid in eukaryotic and prokaryotic organisms. Under conditions of high ammonia concentration, this deamination reaction is reversible and hence there is considerable interest in the development of PALs as biocatalysts for the enantioselective synthesis of non-natural amino acids. Herein the discovery of a previously unobserved competing MIO-independent reaction pathway, which proceeds in a non-stereoselective manner and results in the generation of both L- and D-phenylalanine derivatives, is described. The mechanism of the MIO-independent pathway is explored through isotopic-labeling studies and mutagenesis of key active-site residues. The results obtained are consistent with amino acid deamination occurring by a stepwise E1 cB elimination mechanism.

  2. Amines and Ammonia Measured in the Southeastern U.S. Forest during the 2013 SOAS Field Campaign

    NASA Astrophysics Data System (ADS)

    Lee, S.; You, Y.; Sierra-Hernández, M.; Baumann, K.; Fry, J.; Allen, H.; Draper, D. C.; Edgerton, E.

    2013-12-01

    Amines and ammonia play critical roles in new particle formation, via acid-base reactions at the initial stage of aerosol nucleation. Nitrogen base compounds are important for SOA formation, via formation of salts and condensation of amine photo-oxidation products; they also contribute to the formation of brown organic aerosols. Amines and ammonia can change the acidity and physical state of aerosols to further affect SOA yields. During the Southern Oxidant and Aerosol Study (SOAS) campaign in Centerville, Alabama from June 1 to July 15, 2013, amines and ammonia were simultaneously measured with a chemical ionization mass spectrometer (CIMS) by Kent State University [Yu and Lee, 2012: Environ. Chem. 9, 190-201]. The sensitivity of the CIMS was in the range of 5-10 Hz ion signals for 1 pptv of a base compound, which ultimately allows for the fast-time response detection (less than 1 minute) of ammonia and amines at the pptv level. Additionally, ammonia was also detected with another two independent methods, MARGA (Measuring AeRosols and Gases) by Reed College, and chemiluminescence by ARA. Ammonia concentrations measured by CIMS, MARGA and chemiluminescence were at the ppbv and sub-ppbv level. Over the 6 weeks of the SOAS field study, these three ammonia instruments consistently showed very similar time variations and agreed reasonably well. The CIMS also detected various C1 through C6 amines at the pptv and tens pptv level. Trimethylamine (C3 amine) and ammonia showed similar diurnal trends, temperature and wind direction dependences for most days, implying common natural emission sources of these two base compounds at this forest site. On the other hand, methylamine (C1) and dimethylamine (C2) were much lower than trimethylamine and they did not show clear diurnal variations and temperature dependences. During the brief episode of local biomass burning, concentrations of C3 through C6 amines and ammonia increased rapidly, while methylamine and dimethylamine were

  3. Pretreatment of rice straw with combined process using dilute sulfuric acid and aqueous ammonia

    PubMed Central

    2013-01-01

    Background Use of lignocellulosic biomass has received attention lately because it can be converted into various versatile chemical compounds by biological processes. In this study, a two-step pretreatment with dilute sulfuric acid and aqueous ammonia was performed efficiently on rice straw to obtain fermentable sugar. The soaking in aqueous ammonia process was also optimized by a statistical method. Results Response surface methodology was employed. The determination coefficient (R2) value was found to be 0.9607 and the coefficient of variance was 6.77. The optimal pretreatment conditions were a temperature of 42.75°C, an aqueous ammonia concentration of 20.93%, and a reaction time of 48 h. The optimal enzyme concentration for saccharification was 30 filter paper units. The crystallinity index was approximately 60.23% and the Fourier transform infrared results showed the distinct peaks of glucan. Ethanol production using Saccharomyces cerevisiae K35 was performed to verify whether the glucose saccharified from rice straw was fermentable. Conclusions The combined pretreatment using dilute sulfuric acid and aqueous ammonia on rice straw efficiently yielded fermentable sugar and achieved almost the same crystallinity index as that of α-cellulose. PMID:23898802

  4. Urease gene-containing Archaea dominate autotrophic ammonia oxidation in two acid soils.

    PubMed

    Lu, Lu; Jia, Zhongjun

    2013-06-01

    The metabolic traits of ammonia-oxidizing archaea (AOA) and bacteria (AOB) interacting with their environment determine the nitrogen cycle at the global scale. Ureolytic metabolism has long been proposed as a mechanism for AOB to cope with substrate paucity in acid soil, but it remains unclear whether urea hydrolysis could afford AOA greater ecological advantages. By combining DNA-based stable isotope probing (SIP) and high-throughput pyrosequencing, here we show that autotrophic ammonia oxidation in two acid soils was predominately driven by AOA that contain ureC genes encoding the alpha subunit of a putative archaeal urease. In urea-amended SIP microcosms of forest soil (pH 5.40) and tea orchard soil (pH 3.75), nitrification activity was stimulated significantly by urea fertilization when compared with water-amended soils in which nitrification resulted solely from the oxidation of ammonia generated through mineralization of soil organic nitrogen. The stimulated activity was paralleled by changes in abundance and composition of archaeal amoA genes. Time-course incubations indicated that archaeal amoA genes were increasingly labelled by (13) CO2 in both microcosms amended with water and urea. Pyrosequencing revealed that archaeal populations were labelled to a much greater extent in soils amended with urea than water. Furthermore, archaeal ureC genes were successfully amplified in the (13) C-DNA, and acetylene inhibition suggests that autotrophic growth of urease-containing AOA depended on energy generation through ammonia oxidation. The sequences of AOB were not detected, and active AOA were affiliated with the marine Group 1.1a-associated lineage. The results suggest that ureolytic N metabolism could afford AOA greater advantages for autotrophic ammonia oxidation in acid soil, but the mechanism of how urea activates AOA cells remains unclear.

  5. Ammonia-induced oxidative damage in neurons is prevented by resveratrol and lipoic acid with participation of heme oxygenase 1.

    PubMed

    Bobermin, Larissa Daniele; Wartchow, Krista Minéia; Flores, Marianne Pires; Leite, Marina Concli; Quincozes-Santos, André; Gonçalves, Carlos-Alberto

    2015-07-01

    Ammonia is a metabolite that, at high concentrations, is implicated in neurological disorders, such as hepatic encephalopathy (HE), which is associated with acute or chronic liver failure. Astrocytes are considered the primary target of ammonia toxicity in the central nervous system (CNS) because glutamine synthetase (GS), responsible for ammonia metabolism in CNS, is an astrocytic enzyme. Thus, neuronal dysfunction has been associated as secondary to astrocytic impairment. However, we demonstrated that ammonia can induce direct effects on neuronal cells. The cell viability was decreased by ammonia in SH-SY5Y cells and cerebellar granule neurons. In addition, ammonia induced increased reactive oxygen species (ROS) production and decreased GSH intracellular content, the main antioxidant in CNS. As ammonia neurotoxicity is strongly associated with oxidative stress, we also investigated the potential neuroprotective roles of the antioxidants, resveratrol (RSV) and lipoic acid (LA), against ammonia toxicity in cerebellar granule neurons. RSV and LA were able to prevent the oxidative damage induced by ammonia, maintaining the levels of ROS production and GSH close to basal values. Both antioxidants also decreased ROS production and increased GSH content under basal conditions (in the absence of ammonia). Moreover, we showed that heme oxygenase 1 (HO1), a protein associated with protection against stress conditions, is involved in the beneficial effects of RSV and LA in cerebellar granule neurons. Thus, this study reinforces the neuroprotective effects of RSV and LA. Although more studies in vivo are required, RSV and LA could represent interesting therapeutic strategies for the management of HE.

  6. Measurement of partial vapor pressure of ammonia over acid ammonium sulfate solutions by an integral method

    NASA Astrophysics Data System (ADS)

    Koutrakis, P.; Aurian-BlǎJeni, B.

    1993-02-01

    We present a simple, integral, passive method for measuring partial vapor pressure. Integral methods are useful tools when dealing with very low concentrations because collection over extended periods increases the analytical sensitivity. Passive methods have the advantage of not introducing constraints external to the system. The principle of the method used here is to selectively react the substance in the atmosphere over a solution with an immobilized coating on an appropriate support. The reaction product is not volatile, but is soluble and can be extracted in an appropriate solvent and analyzed. The method has been applied to measuring the vapor pressure of ammonia over aqueous solutions. The vapor pressure over ammonium sulfate solutions depends on the acidity of the solutions as well as on the salt concentration. The dependence can be explained with a simple model. Furthermore, using the same model, we calculated the ammonia vapor pressure above different ammonium sulfate/sulfuric acid aqueous solutions as a function of sulfate molarity and percentage of sulfuric acid. The results from the calculations suggest that for ambient ammonia concentrations less than 10 ppb, acid sulfate aerosols are not completely neutralized.

  7. Prebiotic Amino Acid Thioester Synthesis: Thiol-Dependent Amino Acid Synthesis from Formose substrates (Formaldehyde and Glycolaldehyde) and Ammonia

    NASA Technical Reports Server (NTRS)

    Weber, Arthur L.

    1998-01-01

    Formaldehyde and glycolaldehyde (substrates of the formose autocatalytic cycle) were shown to react with ammonia yielding alanine and homoserine under mild aqueous conditions in the presence of thiol catalysts. Since similar reactions carried out without ammonia yielded alpha-hydroxy acid thioesters, the thiol-dependent synthesis of alanine and homoserine is presumed to occur via amino acid thioesters-intermediates capable of forming peptides. A pH 5.2 solution of 20 mM formaldehyde, 20 mM glycolaldehyde, 20 mM ammonium chloride, 23 mM 3-mercaptopropionic acid, and 23 mM acetic acid that reacted for 35 days at 40 C yielded (based on initial formaldehyde) 1.8% alanine and 0.08% homoserine. In the absence of thiol catalyst, the synthesis of alanine and homoserine was negligible. Alanine synthesis required both formaldehyde and glycolaldehyde, but homoserine synthesis required only glycolaldehyde. At 25 days the efficiency of alanine synthesis calculated from the ratio of alanine synthesized to formaldehyde reacted was 2.1%, and the yield (based on initial formaldehyde) of triose and tetrose intermediates involved in alanine and homoserine synthesis was 0.3 and 2.1%, respectively. Alanine synthesis was also seen in similar reactions containing only 10 mM each of aldehyde substrates, ammonia, and thiol. The prebiotic significance of these reactions that use the formose reaction to generate sugar intermediates that are converted to reactive amino acid thioesters is discussed.

  8. Nitric acid and ammonia emissions from a mid-latitude prescribed wetlands fire

    NASA Technical Reports Server (NTRS)

    Lebel, P. J.; Cofer, W. R., III; Levine, J. S.; Vay, S. A.; Roberts, P. D.

    1988-01-01

    The first simultaneous measurements of gaseous nitric acid and ammonia in the smoke plume of a wetlands biomass burn were obtained. The measurements were made using tungsten oxide-coated diffusion denuder tubes from a helicopter during a prescribed burn on November 9, 1987, at the Merritt Island National Wildlife Refuge, located at the NASA John F. Kennedy Space Center, Florida. The mean NH3 and HNO3 mixing ratios measured in the smoke plume were 19 ppbv and 14 ppbv, respectively, both significantly higher than background mixing ratios. Nitric acid correlated well with carbon dioxide produced by the combustion. The mean CO2-normalized emission ratio for HNO3 was found to be 0.00012. Ammonia, however, dit not correlate well with CO2, suggesting a more complex relationship between combustion and production/release of NH3.

  9. Nitric acid and ammonia emissions from a mid-latitude prescribed wetlands fire

    NASA Astrophysics Data System (ADS)

    LeBel, P. J.; Cofer, W. R., III; Levine, J. S.; Vay, S. A.; Roberts, P. D.

    1988-08-01

    We have obtained the first simultaneous measurements of gaseous nitric acid (HNO3) and ammonia (NH3) in the smoke plume of a wetlands biomass burn. These measurements were made using tungsten oxide-coated diffusion denuder tubes from a helicopter during a prescribed burn at the Merritt Island National Wildlife Refuge, located at the NASA John F. Kennedy Space Center, Florida, on November 9, 1987. The mean NH3 and HNO3 mixing ratios measured in the smoke plume were 19 ppbv and 14 ppbv, respectively, both significantly higher than background mixing ratios. Nitric acid correlated well with carbon dioxide (CO2) produced by the combustion. The mean CO2-normalized emission ratio for HNO3 was found to be 1.2 × 10-4. Ammonia, however, did not correlate well with CO2 suggesting a more complex relationship between combustion and production/release of NH3.

  10. Conversion of Aqueous Ammonia-Treated Corn Stover to Lactic Acid by Simultaneous Saccharification and Cofermentation

    NASA Astrophysics Data System (ADS)

    Zhu, Yongming; Lee, Y. Y.; Elander, Richard T.

    Treatment of corn stover with aqueous ammonia removes most of the structural lignin, whereas retaining the majority of the carbohydrates in the solids. After treatment, both the cellulose and hemicellulose in corn stover become highly susceptible to enzymatic digestion. In this study, corn stover treated by aqueous ammonia was investigated as the substrate for lactic acid production by simultaneous saccharification and cofermentation (SSCF). A commercial cellulase (Spezyme-CP) and Lactobacillus pentosus American Type Culture Collection (ATCC) 8041 (Spanish Type Culture Collection [CECT]-4023) were used for hydrolysis and fermentation, respectively. In batch SSCF operation, the carbohydrates in the treated corn stover were converted to lactic acid with high yields, the maximum lactic acid yield reaching 92% of the stoichiometric maximum based on total fermentable carbohydrates (glucose, xylose, and arabinose). A small amount of acetic acid was also produced from pentoses through the phosphoketolase pathway. Among the major process variables for batch SSCF, enzyme loading and the amount of yeast extract were found to be the key factors affecting lactic acid production. Further tests on nutrients indicated that corn steep liquor could be substituted for yeast extract as a nitrogen source to achieve the same lactic acid yield. Fed-batch operation of the SSCF was beneficial in raising the concentration of lactic acid to a maximum value of 75.0 g/L.

  11. Enhancement of a Lewis acid-base interaction via solvation: ammonia molecules and the benzene radical cation.

    PubMed

    Chiang, Chi-Tung; Freindorf, Marek; Furlani, Thomas; DeLeon, Robert L; Richard, John P; Garvey, James F

    2007-07-12

    The interaction between ammonia and the benzene radical cation has been investigated by gas-phase studies of mass selected ion clusters {C(6)H(6)-(NH(3))(n=0-8)}(+) via tandem quadrupole mass spectrometry and through calculations. Experiments show a special stability for the cluster ion that contains four ammonias: {C(6)H(6)(NH(3))(4)}(+). Calculations provide evidence that the first ammonia forms a weak dative bond to the cyclohexadienyl radical cation, {C(6)H(6)-NH(3)}(+), where there is a transfer of electrons from ammonia to benzene. Additional solvating ammonia molecules form stabilizing hydrogen bonds to the ring-bound ammonia {C(6)H(6)-NH(3)}(+).(NH(3))(n), which cause cooperative changes in the structure of the cluster complex. Free ammonia is a weak hydrogen bond donor, but electron transfer from NH(3) to the benzene ring that strengthens the dative bond will increase the hydrogen acidity and the strength of the cluster hydrogen bonds to the added ammonia. A progressive "tightening" of this dative bond is observed upon addition of the first, second, and third ammonia to give a cluster stabilized by three N-(+)H x N hydrogen bonds. This shows that the energetic cost of tightening the dative bond is recovered with dividends in the formation of stable cluster hydrogen bonds.

  12. Ammonia lyases and aminomutases as biocatalysts for the synthesis of α-amino and β-amino acids.

    PubMed

    Turner, Nicholas J

    2011-04-01

    Ammonia lyases catalyse the reversible addition of ammonia to cinnamic acid (1: R=H) and p-hydroxycinnamic (1: R=OH) to generate L-phenylalanine (2: R=H) and L-tyrosine (2: R=OH) respectively (Figure 1a). Both phenylalanine ammonia lyase (PAL) and tyrosine ammonia lyase (TAL) are widely distributed in plants, fungi and prokaryotes. Recently there has been interest in the use of these enzymes for the synthesis of a broader range of L-arylalanines. Aminomutases catalyse a related reaction, namely the interconversion of α-amino acids to β-amino acids (Figure 1b). In the case of L-phenylalanine, this reaction is catalysed by phenylalanine aminomutase (PAM) and proceeds stereospecifically via the intermediate cinnamic acid to generate β-Phe 3. Ammonia lyases and aminomutases are related in sequence and structure and share the same active site cofactor 4-methylideneimidazole-5-one (MIO). There is currently interest in the possibility of using these biocatalysts to prepare a wide range of enantiomerically pure l-configured α-amino and β-amino acids. Recent reviews have focused on the mechanism of these MIO containing enzymes. The aim of this review is to review recent progress in the application of ammonia lyase and aminomutase enzymes to prepare enantiomerically pure α-amino and β-amino acids.

  13. Ammonia activates pacC and patulin accumulation in an acidic environment during apple colonization by Penicillium expansum.

    PubMed

    Barad, Shiri; Espeso, Eduardo A; Sherman, Amir; Prusky, Dov

    2016-06-01

    Penicillium expansum, the causal agent of blue mould rot, causes severe post-harvest fruit maceration simultaneously with the secretion of d-gluconic acid (GLA) and the mycotoxin patulin in colonized tissue. The factor(s) inducing patulin biosynthesis during colonization of the host acidic environment is unclear. During the colonization of apple fruit in vivo and growth in culture, P. expansum secretes pH-modulating GLA and ammonia. Although patulin and its possible opportunistic precursor GLA accumulate together during fungal development, ammonia is detected on the colonized tissue's leading edge and after extended culture, close to patulin accumulation. Here, we demonstrate ammonia-induced transcript activation of the global pH modulator PacC and patulin accumulation in the presence of GLA by: (i) direct exogenous treatment of P. expansum growing on solid medium; (ii) direct exogenous treatment on colonized apple tissue; (iii) growth under self-ammonia production conditions with limited carbon; and (iv) analysis of the transcriptional response to ammonia of the patulin biosynthesis cluster. Ammonia induced patulin accumulation concurrently with the transcript activation of pacC and patulin biosynthesis cluster genes, indicating the regulatory effect of ammonia on pacC transcript expression under acidic conditions. Electrophoretic mobility shift assays using P. expansum PacC and antibodies to the different cleaved proteins showed that PacC is not protected against proteolytic signalling at pH 4.5 relative to pH 7.0, but NH4 addition did not further enhance its proteolytic cleavage. Ammonia enhanced the activation of palF transcript in the Pal pathway under acidic conditions. Ammonia accumulation in the host environment by the pathogen under acidic pH may be a regulatory cue for pacC activation, towards the accumulation of secondary metabolites, such as patulin.

  14. Ammonia activates pacC and patulin accumulation in an acidic environment during apple colonization by Penicillium expansum.

    PubMed

    Barad, Shiri; Espeso, Eduardo A; Sherman, Amir; Prusky, Dov

    2016-06-01

    Penicillium expansum, the causal agent of blue mould rot, causes severe post-harvest fruit maceration simultaneously with the secretion of d-gluconic acid (GLA) and the mycotoxin patulin in colonized tissue. The factor(s) inducing patulin biosynthesis during colonization of the host acidic environment is unclear. During the colonization of apple fruit in vivo and growth in culture, P. expansum secretes pH-modulating GLA and ammonia. Although patulin and its possible opportunistic precursor GLA accumulate together during fungal development, ammonia is detected on the colonized tissue's leading edge and after extended culture, close to patulin accumulation. Here, we demonstrate ammonia-induced transcript activation of the global pH modulator PacC and patulin accumulation in the presence of GLA by: (i) direct exogenous treatment of P. expansum growing on solid medium; (ii) direct exogenous treatment on colonized apple tissue; (iii) growth under self-ammonia production conditions with limited carbon; and (iv) analysis of the transcriptional response to ammonia of the patulin biosynthesis cluster. Ammonia induced patulin accumulation concurrently with the transcript activation of pacC and patulin biosynthesis cluster genes, indicating the regulatory effect of ammonia on pacC transcript expression under acidic conditions. Electrophoretic mobility shift assays using P. expansum PacC and antibodies to the different cleaved proteins showed that PacC is not protected against proteolytic signalling at pH 4.5 relative to pH 7.0, but NH4 addition did not further enhance its proteolytic cleavage. Ammonia enhanced the activation of palF transcript in the Pal pathway under acidic conditions. Ammonia accumulation in the host environment by the pathogen under acidic pH may be a regulatory cue for pacC activation, towards the accumulation of secondary metabolites, such as patulin. PMID:26420024

  15. Ammonia gas sensing behavior of tanninsulfonic acid doped polyaniline-TiO₂ composite.

    PubMed

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

    2015-10-16

    A highly active tannin doped polyaniline-TiO₂ composite ammonia gas sensor was developed and the mechanism behind the gas sensing activity was reported for the first time. A tanninsulfonic acid doped polyaniline (TANIPANI)-titanium dioxide nanocomposite was synthesized by an in situ polymerization of aniline in the presence of tanninsulfonic acid and titanium dioxide nanoparticles. X-ray diffraction and thermogravimetric analysis were utilized to determine the incorporation of TiO₂ in TANIPANI matrix. UV-Visible and infrared spectroscopy studies provided information about the electronic interactions among tannin, polyaniline, and TiO₂. Scanning electron microscopy (SEM) along with energy dispersive X-ray spectroscopy (EDS) and atomic force microscopy (AFM) surface analysis techniques were used to investigate the metal oxide dispersions inside polyaniline matrix. Gas sensors were prepared by spin coating solutions of TANIPANI-TiO₂ and TANIPANI composites onto glass slides. Sensors were tested at three different concentrations (20 ppm, 40 ppm, and 60 ppm) of ammonia gas at ambient temperature conditions by measuring the changes in surface resistivity of the films with respect to time. Ammonia gas sensing plots are presented showing the response values, response times and recovery times. The TANIPANI-TiO₂ composite exhibited better response and shorter recovery times when compared to TANIPANI control and other polyaniline composites that have been reported in the literature. For the first time a proposed mechanism of gas sensing basing on the polaron band localization and its effects on the gas sensing behavior of polyaniline are reported.

  16. Ammonia emission factors for the NAPAP (National Acid Precipitation Assessment Program) emission inventory. Final report, January 1985-December 1986

    SciTech Connect

    Misenheimer, D.C.; Warn, T.E.; Zelmanowitz, S.

    1987-01-01

    The report provides information on certain sources of ammonia emissions to the atmosphere for use in the National Acid Precipitation Assessment Program (NAPAP) emission inventories. Major anthropogenic sources of ammonia emissions to the atmosphere are identified, and emission factors for these sources are presented based on a review of the most recent data available. The emission factors developed are used to estimate nationwide emissions for base year 1980 and are compared to ammonia emission factors used in other emission inventories. Major anthropogenic source categories covered are cropland spreading of livestock wastes, beef cattle feedlots, fertilizer manufacture and use, fuel combustion, ammonia synthesis, petroleum refineries, and coke manufacture. Approximately 840,000 tons of ammonia is estimated to have been emitted in the U.S. in 1980; over 64% of which is estimated to have been from livestock wastes.

  17. A Density Functional Theory Study of Temperature Dependence of Cluster Formation from Sulfuric Acid and Ammonia

    NASA Astrophysics Data System (ADS)

    lin, H.; Chon, N. L.; Lee, S.

    2013-12-01

    Recent atmospheric nucleation studies have shown that acid-base reactions are essential at the initial step of aerosol nucleation. Ammonia is the most abundant base compound present in the atmosphere. Ammonia can directly interact with sulfuric acid clusters to reduce Gibbs free energy of cluster formation and growth, but the role that ammonia plays in atmospheric nucleation is still not well understood, especially at the molecular cluster level. We have performed density functional theory (BL3YP) and ab initio (MP2) calculations to study energetics of cluster formation for (NH3)m(H2SO4) and (NH3)(H2SO4)n (m, n = 1-6) in the temperature range from 200-300 K. For the model (NH3)m(H2SO4) clusters, bindings were predicted to increase from m = 1 to 6 at 200 K, while the most stable complex at 300 K was found to be at m = 2. For the (NH3)(H2SO4)n complexes, enthalpic contributions dominated and the binding is more stable for larger n. The temperature dependency has stronger effects on the (NH3)m(H2SO4) complexes, among which the lowest free energy shifts from m = 6 at T = 200 K to m = 5 around T = 240 K and further to m = 2 at T ≥ 280 K. The effects on the (NH3)(H2SO4)n complexes are much smaller, while there are similar trends that favor larger n for all temperatures between 200 and 300 K. These results thus indicate that the role of ammonia in atmospheric aerosol nucleation is critical in a wide range of atmospheric temperature conditions.

  18. Synthesis and characterization of amylose grafted poly(acrylic acid) and its application in ammonia adsorption.

    PubMed

    Chen, Qing; Yu, Haojie; Wang, Li; Abdin, Zain-Ul; Yang, Xinpeng; Wang, Junhua; Zhou, Weidong; Zhang, Hongtao; Chen, Xiao

    2016-11-20

    Amylose grafted poly(acrylic acid) (Am-g-PAA) was synthesized by graft copolymerization of amylose with acrylic acid. The structure of Am-g-PAA was confirmed by (1)H NMR and FT-IR spectra. The morphology, crystallinity and thermal properties of amylose and Am-g-PAA were investigated by SEM, XRD and TGA, respectively. The highest degree of substitution (DS) of carboxyl group was 1.96 which was obtained after reacted for 1h at 60°C. Acrylic acid to anhydroglucose mole ratio for DS was 19.81. It was found that a large number of carboxyl groups were grafted on the backbone of amylose. It was also found that ammonia adsorption capacity of amylose increased by grafting poly(acrylic acid) on the backbone of amylose. PMID:27561514

  19. Ammonia-oxidizing activity and microbial community structure in acid tea (Camellia sinensis) orchard soil

    NASA Astrophysics Data System (ADS)

    Okamura, K.; Takanashi, A.; Yamada, T.; Hiraishi, A.

    2012-03-01

    The purpose of this study was to determine the ammonia-oxidizing activity and the phylogentic composition of microorganisms involved in acid tea (Camellia sinensis) orchard soil. All soil samples were collected from three sites located in Tahara and Toyohashi, Aichi Prefecture, Japan. The potential nitrification rate (PNR) was measured by the chlorate inhibition method. The soil pH of tea orchards studied ranged from 2.78 to 4.84, differing significantly from sample to sample, whereas that of meadow and unplanted fields ranged from 5.78 to 6.35. The PNR ranged from 0.050 to 0.193 μg NO2--Ng-1 h-1 and were positively correlated with the soil pH (r2 = 0.382, p<0.001). Bulk DNA was extracted from a tea orchard soil (pH 4.8; PNR, 0.078 μg NO2--Ng-1 h-1) and subjected to PCR-aided clone library analyses targeting archaeal and bacterial amoA genes. The detected archaeal clones separated from the cluster of the 'Soil clones' and tightly clustered with the clones originating from other acidic soil environments including the Chinese tea orchard soil. These results suggest that the specific archaeal populations dominate as the ammonia oxidizers in acid tea-orchard soils and possibly other acid soils, independent of geographic locations, which results from the adaptation to specific ecological niches.

  20. Active Ammonia Oxidizers in an Acidic Soil Are Phylogenetically Closely Related to Neutrophilic Archaeon

    PubMed Central

    Wang, Baozhan; Zheng, Yan; Huang, Rong; Zhou, Xue; Wang, Dongmei; He, Yuanqiu

    2014-01-01

    All cultivated ammonia-oxidizing archaea (AOA) within the Nitrososphaera cluster (former soil group 1.1b) are neutrophilic. Molecular surveys also indicate the existence of Nitrososphaera-like phylotypes in acidic soil, but their ecological roles are poorly understood. In this study, we present molecular evidence for the chemolithoautotrophic growth of Nitrososphaera-like AOA in an acidic soil with pH 4.92 using DNA-based stable isotope probing (SIP). Soil microcosm incubations demonstrated that nitrification was stimulated by urea fertilization and accompanied by a significant increase in the abundance of AOA rather than ammonia-oxidizing bacteria (AOB). Real-time PCR analysis of amoA genes as a function of the buoyant density of the DNA gradient following the ultracentrifugation of the total DNA extracted from SIP microcosms indicated a substantial growth of soil AOA during nitrification. Pyrosequencing of the total 16S rRNA genes in the “heavy” DNA fractions suggested that archaeal communities were labeled to a much greater extent than soil AOB. Acetylene inhibition further showed that 13CO2 assimilation by nitrifying communities depended solely on ammonia oxidation activity, suggesting a chemolithoautotrophic lifestyle. Phylogenetic analysis of both 13C-labeled amoA and 16S rRNA genes revealed that most of the active AOA were phylogenetically closely related to the neutrophilic strains Nitrososphaera viennensis EN76 and JG1 within the Nitrososphaera cluster. Our results provide strong evidence for the adaptive growth of Nitrososphaera-like AOA in acidic soil, suggesting a greater metabolic versatility of soil AOA than previously appreciated. PMID:24375137

  1. Active ammonia oxidizers in an acidic soil are phylogenetically closely related to neutrophilic archaeon.

    PubMed

    Wang, Baozhan; Zheng, Yan; Huang, Rong; Zhou, Xue; Wang, Dongmei; He, Yuanqiu; Jia, Zhongjun

    2014-03-01

    All cultivated ammonia-oxidizing archaea (AOA) within the Nitrososphaera cluster (former soil group 1.1b) are neutrophilic. Molecular surveys also indicate the existence of Nitrososphaera-like phylotypes in acidic soil, but their ecological roles are poorly understood. In this study, we present molecular evidence for the chemolithoautotrophic growth of Nitrososphaera-like AOA in an acidic soil with pH 4.92 using DNA-based stable isotope probing (SIP). Soil microcosm incubations demonstrated that nitrification was stimulated by urea fertilization and accompanied by a significant increase in the abundance of AOA rather than ammonia-oxidizing bacteria (AOB). Real-time PCR analysis of amoA genes as a function of the buoyant density of the DNA gradient following the ultracentrifugation of the total DNA extracted from SIP microcosms indicated a substantial growth of soil AOA during nitrification. Pyrosequencing of the total 16S rRNA genes in the "heavy" DNA fractions suggested that archaeal communities were labeled to a much greater extent than soil AOB. Acetylene inhibition further showed that (13)CO2 assimilation by nitrifying communities depended solely on ammonia oxidation activity, suggesting a chemolithoautotrophic lifestyle. Phylogenetic analysis of both (13)C-labeled amoA and 16S rRNA genes revealed that most of the active AOA were phylogenetically closely related to the neutrophilic strains Nitrososphaera viennensis EN76 and JG1 within the Nitrososphaera cluster. Our results provide strong evidence for the adaptive growth of Nitrososphaera-like AOA in acidic soil, suggesting a greater metabolic versatility of soil AOA than previously appreciated.

  2. Metabolism of branched-chain amino acids and ammonia during exercise: clues from McArdle's disease.

    PubMed

    Wagenmakers, A J; Coakley, J H; Edwards, R H

    1990-05-01

    Patients with McArdle's disease (myophosphorylase deficiency) cannot use muscle glycogen as an energy source during exercise. They therefore are an ideal model to learn about the metabolic adaptations which develop during endurance exercise leading to glycogen depletion. This review summarizes the current knowledge of ammonia and amino acid metabolism in these patients and also adds several new data. During incremental exercise tests in patients with McArdle's disease, forearm venous plasma ammonia concentration rises to a value between 200 and 500 microM. Femoral arteriovenous difference studies show that muscle produces the ammonia. The leg release of both ammonia and glutamine (in mumol/min) has been estimated to be five- to tenfold larger in one of these patients than in healthy individuals exercising at comparable relative work load. Patients with McArdle's disease have a larger uptake of branched-chain amino acids (BCAA) by exercising leg muscles and show a more rapid activation of the muscle branched-chain 2-oxo acid dehydrogenase complex, a key enzyme in the degradation of the BCAA. In general, supplements of BCAA taken before the exercise test lead to a deterioration of exercise performance and a higher increase in heart rate and plasma ammonia during exercise, whereas supplements of branched-chain 2-oxo acids improve exercise performance and lead to a smaller increase in heart rate and plasma ammonia. At constant power output, patients with McArdle's disease show a rapid increase in heart rate and exertion perceived in the exercising muscles, which peak within 10 min after the start of exercise and then fall again ("second wind"). Peak heart rate and peak exertion coincide with a peak in plasma ammonia. Ammonia production during exercise in these patients is estimated to exceed the reported breakdown of ATP to IMP and therefore most likely originates from the metabolism of amino acids. Deamination of amino acids via the reactions of the purine nucleotide

  3. Semi-mechanistic modelling of ammonia absorption in an acid spray wet scrubber based on mass balance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A model to describe reactive absorption of ammonia (NH3) in an acid spray scrubber was developed as a function of the combined overall mass transfer coefficient K. An experimental study of NH3 absorption using 1% dilute sulphuric acid was carried out under different operating conditions. An empiric...

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

    PubMed Central

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

    2015-01-01

    A highly active tannin doped polyaniline-TiO2 composite ammonia gas sensor was developed and the mechanism behind the gas sensing activity was reported for the first time. A tanninsulfonic acid doped polyaniline (TANIPANI)-titanium dioxide nanocomposite was synthesized by an in situ polymerization of aniline in the presence of tanninsulfonic acid and titanium dioxide nanoparticles. X-ray diffraction and thermogravimetric analysis were utilized to determine the incorporation of TiO2 in TANIPANI matrix. UV-Visible and infrared spectroscopy studies provided information about the electronic interactions among tannin, polyaniline, and TiO2. Scanning electron microscopy (SEM) along with energy dispersive X-ray spectroscopy (EDS) and atomic force microscopy (AFM) surface analysis techniques were used to investigate the metal oxide dispersions inside polyaniline matrix. Gas sensors were prepared by spin coating solutions of TANIPANI-TiO2 and TANIPANI composites onto glass slides. Sensors were tested at three different concentrations (20 ppm, 40 ppm, and 60 ppm) of ammonia gas at ambient temperature conditions by measuring the changes in surface resistivity of the films with respect to time. Ammonia gas sensing plots are presented showing the response values, response times and recovery times. The TANIPANI-TiO2 composite exhibited better response and shorter recovery times when compared to TANIPANI control and other polyaniline composites that have been reported in the literature. For the first time a proposed mechanism of gas sensing basing on the polaron band localization and its effects on the gas sensing behavior of polyaniline are reported. PMID:26501291

  5. Ecosystem-specific selection of microbial ammonia oxidizers in an acid soil

    NASA Astrophysics Data System (ADS)

    Saiful Alam, M.; Ren, G.; Lu, L.; Zheng, Y.; Peng, X.; Jia, Z.

    2013-01-01

    The function of ammonia-oxidizing archaea (AOA) and bacteria (AOB) depends on the availability of ammonia substrate and the supply of oxygen. The interactions and evolutions of AOA and AOB communities along ecological gradients of substrate availability in complex environment have been much debated, but rarely tested. In this study, two ecosystems of maize and rice crops under different fertilization regimes were selected to investigate the community diversification of soil AOA and AOB in response to long-term field fertilization and flooding management in an acid soil. Real-time quantitative PCR of amoA genes demonstrated that the abundance of AOA was significantly stimulated after conversion of upland to paddy soils, while slight decline of AOB populations was observed. DGGE fingerprints of amoA genes further revealed remarkable changes in community compositions of AOA in paddy soil when compared to upland soil. Sequencing analysis revealed that upland soil was dominated by AOA within the soil group 1.1b lineage, while the marine group 1.1a lineage predominated AOA communities in paddy soils. Irrespective of upland and paddy soils, long-term field fertilizations led to higher abundance of amoA genes of AOA and AOB than control treatment that received no fertilization, whereas archaeal amoA gene abundances outnumbered their bacterial counterpart in all samples. Phylogenetic analyses of amoA genes showed that Nitrosospira cluster 3-like AOB dominated bacterial ammonia oxidizers in both paddy and upland soils, regardless of fertilization treatments. The results of this study suggest that the marine group 1.1a AOA could be better adapted to low-oxygen environment than AOA ecotypes of the soil group 1.1b lineage, and implicate that long-term flooding as the dominant selective force driving the community diversification of AOA populations in the acid soil tested.

  6. Gas-aerosol cycling of ammonia and nitric acid in The Netherlands

    NASA Astrophysics Data System (ADS)

    Roelofs, Geert-Jan; Derksen, Jeroen

    2010-05-01

    Atmospheric ammonia and nitric acid are present over NW Europe in large abundance. Observations made during the IMPACT measurement campaign (May 2008, Cabauw, The Netherlands) show a pronounced diurnal cycle of aerosol ammonium and nitrate on relatively dry days. Simultaneously, AERONET data show a distinct diurnal cycle in aerosol optical thickness (AOT). We used a global aerosol-climate model (ECHAM5-HAM) and a detailed aerosol-cloud column model to help analyse the observations from this period. The study shows that the diurnal cycle in AOT is partly associated with particle number concentration, with distinct peaks in the morning and evening. More important is relative humidity (RH). RH maximizes in the night and early morning, decreases during the morning and increases again in the evening. The particle wet radius, and therefore AOT, changes accordingly. In addition, the RH variability also influences chemistry associated with ammonia and nitric acid (formation of ammonium nitrate, dissolution in aerosol water), resulting in the observed diurnal cycle of aerosol ammonium and nitrate. The additional aerosol matter increases the hygroscopicity of the particles, and this leads to further swelling by water vapor condensation and a further increase of AOT. During the day, as RH decreases and the particles shrink, aerosol ammonium and nitrate are again partly expelled to the gas phase. This behaviour contributes significantly to the observed diurnal cycle in AOT, and it illustrates the complexity of using AOT as a proxy for aerosol concentrations in aerosol climate studies in the case of heavily polluted areas.

  7. Ammonia Formation by the Reduction of Nitrite/Nitrate by FeS: Ammonia Formation Under Acidic Conditions

    NASA Technical Reports Server (NTRS)

    Summers, David P.; DeVincenzi, Donald (Technical Monitor)

    2000-01-01

    FeS reduces nitrite to, ammonia at pHs lower than the corresponding reduction by aqueous Fe+2. The reduction follows a reasonable first order decay, in nitrite concentration, with a half life of about 150 min (room temperature, CO2, pH 6.25). The highest ammonia product yield measured was 53%. Under CO2, the product yield decreases from pH 5.0 to pH 6.9. The increasing concentration of bicarbonate at higher pH interferes with the reaction. Bicarbonate interference is shown by comparing runs under N2 and CO2. The reaction proceeds well in the presence of such species as chloride, sulfate, and phosphate though the yield drops significantly with phosphate. FeS also reduces nitrate and, unlike with Fe+2, the reduction shows more reproducibility. Again, the product yield decreases with increasing pH, from 7% at pH 4.7 to 0% at pH 6.9. It appears as if nitrate is much more sensitive to the presence of added species, perhaps not competing as well for binding sites on the FeS surface. This may be the cause of the lack of reproducibility of nitrate reduction by Fe+2 (which also can be sensitive to binding by certain species).

  8. Process and apparatus for recovery of sulfur from ammonia containing acid gas streams

    SciTech Connect

    Palm, J.W.

    1987-02-17

    This patent describes a Claus process for the recovery of sulfur, the steps comprising: passing a first stream containing hydrogen sulfide, sulfur dioxide, and ammonia through a low temperature Claus catalytic conversion zone and depositing elemental sulfur and ammonium compounds on catalyst therein; deriving a regeneration stream from the Claus process and regenerating the resulting laden catalyst therewith vaporizing sulfur and ammonia therefrom and producing a regeneration effluent stream comprising elemental sulfur and ammonia; cooling the regeneration effluent stream and condensing elemental sulfur therefrom and producing a sulfur lean regeneration effluent stream; introducing at least a portion of the sulfur lean regeneration effluent stream into a hydrogenation zone and converting substantially all sulfur compounds therein to hydrogen sulfide. The resulting hydrogen sulfide containing stream is introduced into an ammonia removal zone. The resulting stream is contacted with a first aqueous stream and produces a second aqueous stream enriched in ammonia and a sulfur lean regeneration effluent stream reduced in ammonia content; removing ammonia from the second aqueous stream and producing an ammonia enriched stream; returning the sulfur lean regeneration effluent stream reduced in ammonia content to the Claus process adjacent and downstream of the point of derivation of the regeneration stream for the further recovery of sulfur therefrom; and introducing the ammonia enriched stream into an ammonia conversion zone and reducing the concentration of ammonia therein.

  9. Metal-Free Ammonia-Borane Dehydrogenation Catalyzed by a Bis(borane) Lewis Acid.

    PubMed

    Lu, Zhenpin; Schweighauser, Luca; Hausmann, Heike; Wegner, Hermann A

    2015-12-14

    The storage of energy in a safe and environmentally benign way is one of the main challenges of today's society. Ammonia-borane (AB=NH3 BH3 ) has been proposed as a possible candidate for the chemical storage of hydrogen. However, the efficient release of hydrogen is still an active field of research. Herein, we present a metal-free bis(borane) Lewis acid catalyst that promotes the evolution of up to 2.5 equivalents of H2 per AB molecule. The catalyst can be reused multiple times without loss of activity. The moderate temperature of 60 °C allows for controlling the supply of H2 on demand simply by heating and cooling. Mechanistic studies give preliminary insights into the kinetics and mechanism of the catalytic reaction. PMID:26537288

  10. [Microbial diversity and ammonia-oxidizing microorganism of a soil sample near an acid mine drainage lake].

    PubMed

    Liu, Ying; Wang, Li-Hua; Hao, Chun-Bo; Li, Lu; Li, Si-Yuan; Feng, Chuan-Ping

    2014-06-01

    The main physicochemical parameters of the soil sample which was collected near an acid mine drainage reservoir in Anhui province was analyzed. The microbial diversity and community structure was studied through the construction of bacteria and archaea 16S rRNA gene clone libraries and ammonia monooxygenase gene clone library of archaea. The functional groups which were responsible for the process of ammonia oxidation were also discussed. The results indicated that the soil sample had extreme low pH value (pH < 3) and high ions concentration, which was influenced by the acid mine drainage (AMD). All the 16S rRNA gene sequences of bacteria clone library fell into 11 phyla, and Acidobacteria played the most significant role in the ecosystem followed by Verrucomicrobia. A great number of acidophilic bacteria existed in the soil sample, such as Candidatus Koribacter versatilis and Holophaga sp.. The archaea clone library consisted of 2 phyla (Thaumarchaeota and Euryarchaeota). The abundance of Thaumarchaeota was remarkably higher than Euryarchaeota. The ammonia oxidation in the soil environment was probably driven by ammonia-oxidizing archaea, and new species of ammonia-oxidizing archaea existed in the soil sample.

  11. Hops (Humulus lupulus) ß-acid as an inhibitor of caprine rumen hyper-ammonia-producing bacteria in vitro

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Antimicrobial plant secondary metabolites increase rumen efficiency and decrease waste products (i.e. ammonia, methane) in some cases. A promising source of bioactive secondary metabolites is the hops plant (Humulus lupulus L.), which produces '-acid, a suite of structurally similar, potent antibact...

  12. Novel Regenerated Solvent Extraction Processes for the Recovery of Carboxylic Acids or Ammonia from Aqueous Solutions Part I. Regeneration of Amine-Carboxylic Acid Extracts

    SciTech Connect

    Poole, L.J.; King, C.J.

    1990-03-01

    Two novel regenerated solvent extraction processes are examined. The first process has the potential to reduce the energy costs inherent in the recovery of low-volatility carboxylic acids from dilute aqueous solutions. The second process has the potential for reducing the energy costs required for separate recovery of ammonia and acid gases (e.g. CO{sub 2} and H{sub 2}S) from industrial sour waters. The recovery of carboxylic acids from dilute aqueous solution can be achieved by extraction with tertiary amines. An approach for regeneration and product recovery from such extracts is to back-extract the carboxylic acid with a water-soluble, volatile tertiary amine, such as trimethylamine. The resulting trimethylammonium carboxylate solution can be concentrated and thermally decomposed, yielding the product acid and the volatile amine for recycle. Experimental work was performed with lactic acid, succinic acid, and fumaric acid. Equilibrium data show near-stoichiometric recovery of the carboxylic acids from an organic solution of Alamine 336 into aqueous solutions of trimethylamine. For fumaric and succinic acids, partial evaporation of the aqueous back extract decomposes the carboxylate and yields the acid product in crystalline form. The decomposition of aqueous solutions of trimethylammonium lactates was not carried out to completion, due to the high water solubility of lactic acid and the tendency of the acid to self-associate. The separate recovery of ammonia and acid gases from sour waters can be achieved by combining steam-stripping of the acid gases with simultaneous removal of ammonia by extraction with a liquid cation exchanger. The use of di-2,4,4-trimethylpentyl phosphinic acid as the liquid cation exchanger is explored in this work. Batch extraction experiments were carried out to measure the equilibrium distribution ratio of ammonia between an aqueous buffer solution and an organic solution of the phosphinic acid (0.2N) in Norpar 12. The concentration

  13. UV – INDUCED SYNTHESIS OF AMINO ACIDS FROM AQUEOUS STERILIZED SOLUTION OF AMMONIUM FORMATE AND AMMONIA UNDER HETROGENEOUS CONDITIONS

    PubMed Central

    Bisht, G.; Bisht, L. S.

    1990-01-01

    Irradiation of sterilized aqueous solution of ammonium formate and ammonia with UV light in the presence and or absence of certain inorganic sensitizers for 25 hrs. gave six ninhydrin positive products in appreciable amounts. Out of the six products observed fiver were characterized as lysine, serine, glutemic acid, n-amino butyric acid and leucine. The sensitizing effect of additives on ammonium formate was observed in the order; uranium oxide > ammonium formate > ferric oxide > arsenic oxide. PMID:22556511

  14. Effects of calcination temperature and acid-base properties on mixed potential ammonia sensors modified by metal oxides.

    PubMed

    Satsuma, Atsushi; Katagiri, Makoto; Kakimoto, Shiro; Sugaya, Satoshi; Shimizu, Kenichi

    2011-01-01

    Mixed potential sensors were fabriated using yttria-stabilized zirconia (YSZ) as a solid electrolyte and a mixture of Au and various metal oxides as a sensing electrode. The effects of calcination temperature ranging from 600 to 1,000 °C and acid-base properties of the metal oxides on the sensing properties were examined. The selective sensing of ammonia was achieved by modification of the sensing electrode using MoO(3), Bi(2)O(3) and V(2)O(5), while the use of WO(3,) Nb(2)O(5) and MgO was not effective. The melting points of the former group were below 820 °C, while those of the latter group were higher than 1,000 °C. Among the former group, the selective sensing of ammonia was strongly dependent on the calcination temperature, which was optimum around melting point of the corresponding metal oxides. The good spreading of the metal oxides on the electrode is suggested to be one of the important factors. In the former group, the relative response of ammonia to propene was in the order of MoO(3) > Bi(2)O(3) > V(2)O(5), which agreed well with the acidity of the metal oxides. The importance of the acidic properties of metal oxides for ammonia sensing was clarified.

  15. Effects of Calcination Temperature and Acid-Base Properties on Mixed Potential Ammonia Sensors Modified by Metal Oxides

    PubMed Central

    Satsuma, Atsushi; Katagiri, Makoto; Kakimoto, Shiro; Sugaya, Satoshi; Shimizu, Kenichi

    2011-01-01

    Mixed potential sensors were fabriated using yttria-stabilized zirconia (YSZ) as a solid electrolyte and a mixture of Au and various metal oxides as a sensing electrode. The effects of calcination temperature ranging from 600 to 1,000 °C and acid-base properties of the metal oxides on the sensing properties were examined. The selective sensing of ammonia was achieved by modification of the sensing electrode using MoO3, Bi2O3 and V2O5, while the use of WO3, Nb2O5 and MgO was not effective. The melting points of the former group were below 820 °C, while those of the latter group were higher than 1,000 °C. Among the former group, the selective sensing of ammonia was strongly dependent on the calcination temperature, which was optimum around melting point of the corresponding metal oxides. The good spreading of the metal oxides on the electrode is suggested to be one of the important factors. In the former group, the relative response of ammonia to propene was in the order of MoO3 > Bi2O3 > V2O5, which agreed well with the acidity of the metal oxides. The importance of the acidic properties of metal oxides for ammonia sensing was clarified. PMID:22319402

  16. Dispersion in the presence of acetic acid or ammonia confers gliadin-like characteristics to the glutenin in wheat gluten.

    PubMed

    Murakami, Tetsuya; Kitabatake, Naofumi; Tani, Fumito

    2015-02-01

    Spray-dried gluten has unique properties and is commercially available in the food industry worldwide. In this study, we examined the viscoelastic properties of gluten powder prepared by dispersion in the presence of acetic acid or an ammonia solvent and then followed by lyophilization instead of a spray drying. Mixograph measurements showed that the acid- and ammonia-treated gluten powders had marked decreases in the time to peak dough resistance when compared with the control gluten powder. The integrals of the dough resistance and bandwidth for 3 min after peak dough resistance decreased in both treated gluten powders. Similar phenomena were observed when gliadin was supplemented to gluten powders. Basic and acidic conditions were applied to the acid- and ammonia-treated gluten powders, respectively, and the viscoelastic behaviors were found to depend on the pH in the gluten dispersion just before lyophilization. These behaviors suggest that gluten may assume a reversible change in viscoelasticity by a fluctuation in pH during gluten dispersion. SDS-PAGE showed that the extractable proteins substantially increased in some polymeric glutenins including the low molecular weight-glutenin subunit (LMW-GS) when the ammonia-treated gluten powder was extracted with 70% ethanol. In contrast, the extractable proteins markedly increased in many polymeric glutenins including the high molecular weight-glutenin subunit and/or the LMW-GS when the acid-treated gluten powder was extracted with 70% ethanol. It thus follows that the extractability of polymeric glutenin to ethanol increases similarly to gliadin when gluten is exposed to an acidic or a basic pH condition; therefore, glutenin adopts gliadin-like characteristics.

  17. Kinetics of electroless deposition: the copper-dimethylamine borane system.

    PubMed

    Plana, Daniela; Campbell, Andrew I; Patole, Samson N; Shul, Galyna; Dryfe, Robert A W

    2010-06-15

    A kinetic study of the electroless deposition of copper on gold, using dimethylamine borane (DMAB) as a reducing agent, has been carried out. The copper deposition rate in the electroless bath was determined to be 50 nm min(-1), through electrochemical stripping of the copper deposits as well as from direct measurements of the film thickness using atomic force microscopy (AFM). Comparison with a galvanic cell setup, where the two half-reactions were physically separated, yielded a lower deposition rate of 30 nm min(-1). An important kinetic effect of the surface on the oxidation of the reducing agent, and thus on the overall process, was therefore revealed. The efficiency of the process was measured over time, revealing the contribution of side reactions in the cathodic half-cell, particularly during the initial stages of the electroless process.

  18. Development of a Quantum Cascade Laser-Based Detector for Ammonia and Nitric Acid

    SciTech Connect

    Zahniser, Mark S.; Nelson, David D.; McManus, J. Barry; Shorter, Joanne H.; Herndon, Scott C.; Jimenez, Rodrigo

    2005-12-31

    We have developed a compact, robust, atmospheric trace gas detector based on mid-infrared absorption spectroscopy using pulsed quantum cascade (QC) lasers. The spectrometer is suitable for airborne measurements of ammonia, nitric acid, formaldehyde, formic acid, methane, nitrous oxide, carbon monoxide, nitrogen dioxide and other gases that have line-resolved absorption spectra in the mid-infrared spectral region. The QC laser light source operates near room temperature with thermal electric cooling instead of liquid nitrogen which has been previously required for semiconductor lasers in the mid-infrared spectral region. The QC lasers have sufficient output power so that thermal electric cooled detectors may be used in many applications with lower precision requirements. The instrument developed in this program has been used in several field campaigns from both the Aerodyne Mobile Laboratory and from the NOAA WP3 aircraft. The Phase II program has resulted in more than 10 archival publications describing the technology and its applications. Over 12 instruments based on this design have been sold to research groups in Europe and the United States making the program both a commercial as well as a technological success. Anticipated Benefits The development of a sensitive, cryogen-free, mid-infrared absorption method for atmospheric trace gas detection will have wide benefits for atmospheric and environmental research and broader potential commercial applications in areas such as medical diagnostic and industrial process monitoring of gaseous compounds. Examples include air pollution monitoring, breath analysis, combustion exhaust diagnostics, and plasma diagnostics for semi-conductor fabrication. The substitution of near-room temperature QC lasers for cryogenic lead salt TDLs and the resulting simplifications in instrument design and operation will greatly expand the range of applications.

  19. Strong Hydrogen Bonded Molecular Interactions between Atmospheric Diamines and Sulfuric Acid.

    PubMed

    Elm, Jonas; Jen, Coty N; Kurtén, Theo; Vehkamäki, Hanna

    2016-05-26

    We investigate the molecular interaction between methyl-substituted N,N,N',N'-ethylenediamines, propane-1,3-diamine, butane-1,4-diamine, and sulfuric acid using computational methods. Molecular structure of the diamines and their dimer clusters with sulfuric acid is studied using three density functional theory methods (PW91, M06-2X, and ωB97X-D) with the 6-31++G(d,p) basis set. A high level explicitly correlated CCSD(T)-F12a/VDZ-F12 method is used to obtain accurate binding energies. The reaction Gibbs free energies are evaluated and compared with values for reactions involving ammonia and atmospherically relevant monoamines (methylamine, dimethylamine, and trimethylamine). We find that the complex formation between sulfuric acid and the studied diamines provides similar or more favorable reaction free energies than dimethylamine. Diamines that contain one or more secondary amino groups are found to stabilize sulfuric acid complexes more efficiently. Elongating the carbon backbone from ethylenediamine to propane-1,3-diamine or butane-1,4-diamine further stabilizes the complex formation with sulfuric acid by up to 4.3 kcal/mol. Dimethyl-substituted butane-1,4-diamine yields a staggering formation free energy of -19.1 kcal/mol for the clustering with sulfuric acid, indicating that such diamines could potentially be a key species in the initial step in the formation of new particles. For studying larger clusters consisting of a diamine molecule with up to four sulfuric acid molecules, we benchmark and utilize a domain local pair natural orbital coupled cluster (DLPNO-CCSD(T)) method. We find that a single diamine is capable of efficiently stabilizing sulfuric acid clusters with up to four acid molecules, whereas monoamines such as dimethylamine are capable of stabilizing at most 2-3 sulfuric acid molecules. PMID:27128188

  20. Amino Acid Synthesis in Photosynthesizing Spinach Cells: Effects of Ammonia on Pool Sizes and Rates of Labeling from 14CO2

    SciTech Connect

    Larsen, Peder Olesen; Cornwell, Karen L.; Gee, Sherry L.; Bassham, James A.

    1981-08-01

    In this paper, isolated cells from leaves of Spinacia oleracea have been maintained in a state capable of high rates of photosynthetic CO2 fixation for more than 60 hours. The incorporation of 14CO2 under saturating CO2 conditions into carbohydrates, carboxylic acids, and amino acids, and the effect of ammonia on this incorporation have been studied. Total incorporation, specific radioactivity, and pool size have been determined as a function of time for most of the protein amino acids and for γ-aminobutyric acid. The measurements of specific radio-activities and of the approaches to 14C “saturation” of some amino acids indicate the presence and relative sizes of metabolically active and passive pools of these amino acids. Added ammonia decreased carbon fixation into carbohydrates and increased fixation into carboxylic acids and amino acids. Different amino acids were, however, affected in different and highly specific ways. Ammonia caused large stimulatory effects in incorporation of 14C into glutamine (a factor of 21), aspartate, asparagine, valine, alanine, arginine, and histidine. No effect or slight decreases were seen in glycine, serine, phenylalanine, and tyrosine labeling. In the case of glutamate, 14C labeling decreased, but specific radioactivity increased. The production of labeled γ-aminobutyric acid was virtually stopped by ammonia. The results indicate that added ammonia stimulates the reactions mediated by pyruvate kinase and phosphoenolpyruvate carboxylase, as seen with other plant systems. Finally, the data on the effects of added ammonia on total labeling, pool sizes, and specific radioactivities of several amino acids provides a number of indications about the intracellular sites of principal synthesis from carbon skeletons of these amino acids and the selective nature of effects of increased intracellular ammonia concentration on such synthesis.

  1. Nematocyst discharge in Pelagia noctiluca (Cnidaria, Scyphozoa) oral arms can be affected by lidocaine, ethanol, ammonia and acetic acid.

    PubMed

    Morabito, Rossana; Marino, Angela; Dossena, Silvia; La Spada, Giuseppa

    2014-06-01

    Nematocyst discharge and concomitant delivery of toxins is triggered to perform both defence and predation strategies in Cnidarians, and may lead to serious local and systemic reactions in humans. Pelagia noctiluca (Cnidaria, Scyphozoa) is a jellyfish particularly abundant in the Strait of Messina (Italy). After accidental contact with this jellyfish, not discharged nematocysts or even fragments of tentacles or oral arms may tightly adhere to the human skin and, following discharge, severely increase pain and the other adverse consequences of the sting. The aim of the present study is to verify if the local anesthetic lidocaine and other compounds, like alcohols, acetic acid and ammonia, known to provide pain relief after jellyfish stings, may also affect in situ discharge of nematocysts. Discharge was induced by a combined physico-chemical stimulation of oral arms by chemosensitizers (such as N-acetylated sugars, aminoacids, proteins and nucleotides), in the presence or absence of 1% lidocaine, 70% ethanol, 5% acetic acid or 20% ammonia, followed by mechanical stimulation by a non-vibrating test probe. The above mentioned compounds failed to induce discharge per se, and dramatically impaired the chemosensitizer-induced discharge response. We therefore suggest that prompt local treatment of the stung epidermis with lidocaine, acetic acid, ethanol and ammonia may provide substantial pain relief and help in reducing possible harmful local and systemic adverse reaction following accidental contact with P. noctiluca specimens.

  2. Sorption of carboxylic acid from carboxylic salt solutions at PHS close to or above the pK.sub.a of the acid, with regeneration with an aqueous solution of ammonia or low-molecular-weight alkylamine

    DOEpatents

    King, C. Judson; Tung, Lisa A.

    1992-01-01

    Carboxylic acids are sorbed from aqueous feedstocks at pHs close to or above the acids' pH.sub.a into a strongly basic organic liquid phase or onto a basic solid adsorbent or moderately basic ion exchange resin. the acids are freed from the sorbent phase by treating it with aqueous alkylamine or ammonia thus forming an alkylammonium or ammonium carobxylate which dewatered and decomposed to the desired carboxylic acid and the alkylamine or ammonia.

  3. Sorption of carboxylic acid from carboxylic salt solutions at pHs close to or above the pK[sub a] of the acid, with regeneration with an aqueous solution of ammonia or low-molecular-weight alkylamine

    DOEpatents

    King, C.J.; Tung, L.A.

    1992-07-21

    Carboxylic acids are sorbed from aqueous feedstocks at pHs close to or above the acids' pH[sub a] into a strongly basic organic liquid phase or onto a basic solid adsorbent or moderately basic ion exchange resin. The acids are freed from the sorbent phase by treating it with aqueous alkylamine or ammonia thus forming an alkylammonium or ammonium carboxylate which dewatered and decomposed to the desired carboxylic acid and the alkylamine or ammonia. 8 figs.

  4. Investigating the stomatal, cuticular and soil ammonia fluxes over a growing tritical crop under high acidic loads

    NASA Astrophysics Data System (ADS)

    Loubet, B.; Decuq, C.; Personne, E.; Massad, R. S.; Flechard, C.; Fanucci, O.; Mascher, N.; Gueudet, J.-C.; Masson, S.; Durand, B.; Génermont, S.; Fauvel, Y.; Cellier, P.

    2011-10-01

    Ammonia concentration and fluxes were measured above a growing triticale field for two months during May and June 2010 at the NitroEurope crop site in Grignon (Fr-Gri) near Paris, France. The measurement campaign started 15 days following a 40 kg N ha-1 application of an ammonium nitrate solution. A new mini-WEDD (Wet Effluent Denuder) flow injection analyser with three channels (ROSAA, RObust and Sensitive Ammonia Analyser) was used to measure NH3 fluxes using the aerodynamic gradient method. The measured ammonia concentrations varied from 0.01 to 39 μg NH3 m-3 and were largely influenced by advection from the nearby farm. The ammonia fluxes ranged from -560 to 220 ng NH3 m-2 s-1 and averaged -29 ng NH3 m-2 s-1. During some periods the large deposition fluxes could only be explained by a very small surface resistance, which may be due to the high concentrations in certain acid gases (HNO3 and SO2) observed in this suburban area. Ammonia emissions were also measured occasionally. The canopy compensation point Cc was around 1.5 μg NH3 m-3 on average. The canopy emission potential Γc (Cc normalised for the temperature response of the Henry equilibrium) decreased over the course of the measurement campaign from Γc = 2200 to Γc = 450, the latter value being close to the median stomatal emission potential (Γs) for managed ecosystems reported in the literature. The temporal dynamics of the measured NH3 flux compared well with the Surfatm- NH3 model using fitted parameters. The subjectivity of the model fitting is discussed based on a sensitivity analysis.

  5. Investigating the stomatal, cuticular and soil ammonia fluxes over a growing tritical crop under high acidic loads

    NASA Astrophysics Data System (ADS)

    Loubet, B.; Decuq, C.; Personne, E.; Massad, R. S.; Flechard, C.; Fanucci, O.; Mascher, N.; Gueudet, J.-C.; Masson, S.; Durand, B.; Genermont, S.; Fauvel, Y.; Cellier, P.

    2012-04-01

    Ammonia concentration and fluxes were measured above a growing triticale field for two months during May and June 2010 at the NitroEurope crop site in Grignon (Fr-Gri) near Paris, France. The measurement campaign started 15 days following a 40 kg N ha-1 application of an ammonium nitrate solution. A new mini-wedd (Wet Effluent Denuder) flow injection analyser with three channels (ROSAA, RObust and Sensitive Ammonia Analyser) was used to measure NH3 fluxes using the aerodynamic gradient method. The measured ammonia concentrations varied from 0.01 to 39 μg NH3 m-3 and were largely influenced by advection from the nearby farm. The ammonia fluxes ranged from -560 to 220 ng NH3 m-2 s-1 and averaged -29 ng NH3 m-2 s-1. During some periods the large deposition fluxes could only be explained by a very small surface resistance, which may be partly due to the high concentrations of certain acid gases (HNO3 and SO2) observed in this suburban area. Ammonia emissions were also observed. The canopy compensation point Cc was around 1.5 μg NH3 m-3 on average. The canopy emission potential Γc (Cc normalised for the temperature response of the Henry equilibrium) decreased over the course of the measurement campaign from Γc = 2200 to Γc = 450, the latter value being close to the median stomatal emission potential (Γs) and lower than the median ground emission potential (Γg) for managed ecosystems reported in the literature. The temporal dynamics of the measured NH3 flux compared well with the Surfatm-NH3 model using fitted parameters. The subjectivity of the model fitting is discussed based on a sensitivity analysis.

  6. Ambient concentrations of atmospheric ammonia, nitrogen dioxide and nitric acid in an intensive agricultural region

    NASA Astrophysics Data System (ADS)

    Zbieranowski, Antoni L.; Aherne, Julian

    2013-05-01

    The spatial and temporal distribution of ambient atmospheric gaseous reactive nitrogen (Nr) species concentrations (ammonia [NH3], nitrogen dioxide [NO2] and nitric acid [HNO3]) were measured at the field scale in an intensive agricultural region in southern Ontario, Canada. Atmospheric concentrations were measured with the Willems badge diffusive passive sampler (18 sites for NH3, 9 sites for NO2 and HNO3) for one year (April 2010-March 2011; under a two week measurement frequency) within a 15 km × 15 km area. Dry deposition was calculated using the inferential method and estimated across the entire study area. The spatial distribution of emission sources associated with agricultural activity resulted in high spatial variability in annual average ambient NH3 concentrations (<3->8 μg m-3 within a 2 km distance, coefficient of variation ˜50%) and estimated dry deposition (4-13 kg N ha-1 yr-1) between sample sites. In contrast, ambient concentrations and deposition of both NO2 (˜5.2->6.5 μg m-3; 1.0-1.5 kg N ha-1 yr-1) and HNO3 (0.6-0.7 μg m-3; 0.5-1 kg N ha-1 yr-1) had low variability (coefficient of variation <10%). The observed NH3 concentrations accounted for ˜70% of gaseous Nr dry deposition. High NH3 concentrations suggest that reduced nitrogen species (NHx) will continue to make up an increasing fraction of Nr deposition within intensive agricultural regions in southern Ontario under legislated nitrogen oxide emission reductions. Further, estimated total inorganic Nr deposition (15-28 kg N ha-1 yr-1) may lead to potential changes in soil processes, nutrient imbalance and altered composition of mycorrhiza and ground vegetation within adjacent semi-natural ecosystems (estimated at ˜10% of the study area).

  7. Gibberellic Acid-Promoted Lignification and Phenylalanine Ammonia-lyase Activity in a Dwarf Pea (Pisum sativum) 1

    PubMed Central

    Cheng, Christina K.-C.; Marsh, H. V.

    1968-01-01

    The effects of gibberellic acid on lignification in seedlings of a dwarf and a tall cultivar of pea (Pisum sativum) grown under red or white light or in the darkness, were studied. Gibberellic acid (10−6-10−4 m) promoted stem elongation in both light and dark and increased the percentage of lignin in the stems of the light-grown dwarf pea. The gibberellin had no effect on the lignin content of the tall pea although high concentrations (10−4 m) promoted growth of the tall plants. Time course studies indicated that the enhanced lignification in the gibberellin-treated dwarf plants occurred only after a lag period of several days. It was concluded that gibberellic acid-enhanced ligmification had no direct relation to gibberellic acid-promoted growth. The activity of phenylalanine ammonia-lyase (E.C. 4.3.1.5) was higher in gibberellin-treated dwarf plants grown under white or red light than in untreated dwarf plants. Gibberellic acid had no detectable effect on the activity of this enzyme when the plants were grown in darkness, just as it had no effect on lignification under dark conditions. The data suggest that in gibberellin-deficient peas the activity of phenylalanine ammonia-lyase is one of the limiting factors in lignification. PMID:16656968

  8. Gibberellic Acid-Promoted Lignification and Phenylalanine Ammonia-lyase Activity in a Dwarf Pea (Pisum sativum).

    PubMed

    Cheng, C K; Marsh, H V

    1968-11-01

    The effects of gibberellic acid on lignification in seedlings of a dwarf and a tall cultivar of pea (Pisum sativum) grown under red or white light or in the darkness, were studied. Gibberellic acid (10(-6)-10(-4)m) promoted stem elongation in both light and dark and increased the percentage of lignin in the stems of the light-grown dwarf pea. The gibberellin had no effect on the lignin content of the tall pea although high concentrations (10(-4)m) promoted growth of the tall plants. Time course studies indicated that the enhanced lignification in the gibberellin-treated dwarf plants occurred only after a lag period of several days. It was concluded that gibberellic acid-enhanced ligmification had no direct relation to gibberellic acid-promoted growth. The activity of phenylalanine ammonia-lyase (E.C. 4.3.1.5) was higher in gibberellin-treated dwarf plants grown under white or red light than in untreated dwarf plants. Gibberellic acid had no detectable effect on the activity of this enzyme when the plants were grown in darkness, just as it had no effect on lignification under dark conditions. The data suggest that in gibberellin-deficient peas the activity of phenylalanine ammonia-lyase is one of the limiting factors in lignification. PMID:16656968

  9. Infrared spectroscopic probing of dimethylamine clusters in an Ar matrix.

    PubMed

    Li, Siyang; Kjaergaard, Henrik G; Du, Lin

    2016-02-01

    Amines have many atmospheric sources and their clusters play an important role in aerosol nucleation processes. Clusters of a typical amine, dimethylamine (DMA), of different sizes were measured with matrix isolation IR (infrared) and NIR (near infrared) spectroscopy. The NIR vibrations are more separated and therefore it is easier to distinguish different sizes of clusters in this region. The DMA clusters, up to DMA tetramer, have been optimized using density functional methods, and the geometries, binding energies and thermodynamic properties of DMA clusters were obtained. The computed frequencies and intensities of NH-stretching vibrations in the DMA clusters were used to interpret the experimental spectra. We have identified the fundamental transitions of the bonded NH-stretching vibration and the first overtone transitions of the bonded and free NH-stretching vibration in the DMA clusters. Based on the changes in vibrational intensities during the annealing processes, the growth of clusters was clearly observed. The results of annealing processes indicate that DMA molecules tend to form larger clusters with lower energies under matrix temperatures, which is also supported by the calculated reaction energies of cluster formation. PMID:26969545

  10. Acute inhalation toxicity and sensory irritation of dimethylamine. [Rats, mice

    SciTech Connect

    Steinhagen, W.H.; Swenberg, J.A.; Barrow, C.S.

    1982-06-01

    The sensory irritation potential of dimethylamine (DMA) inhalation on male Fischer-344 rats and male Swiss-Webster mice was evaluated by measuring the reflex decrease in respiratory rate. In addition, the six hour LC/sub 50/ for rats exposed to dimetylamine was established. Groups of 3 or 4 rats and mice were exposed for 10 minutes to concentrations of DMA ranging from 49 to 1576 ppm during which time the respiratory rate was monitored and recorded. Sensory irritation concentration-response curves were obtained and RD/sub 50/ values (concentration which elicits a 50% decrease in respiratory rate) were determined to be 573 and 511 ppm for rats and mice, respectively. In another set of experiments seven groups of male rats were exposed to concentrations of DMA ranging from 600 to 6119 ppm for six hours. Mortality counts were made during and for 48 hours post exposure. The six hour LC/sub 50/ was determined to be 4540 ppm. Histopathologic examination of the respiratory tract revealed concentration related changes ranging from ulceration and necrosis to rhinitis, tracheitis, and emphysema. Overall, DMA was found to be less potent as a sensory irritant than other airborne irritants.

  11. Dimethylamine biodegradation by mixed culture enriched from drinking water biofilter.

    PubMed

    Liao, Xiaobin; Chen, Chao; Zhang, Jingxu; Dai, Yu; Zhang, Xiaojian; Xie, Shuguang

    2015-01-01

    Dimethylamine (DMA) is one of the important precursors of drinking water disinfection by-product N-nitrosodimethylamine (NDMA). Reduction of DMA to minimize the formation of carcinogenic NDMA in drinking water is of practical importance. Biodegradation plays a major role in elimination of DMA pollution in the environment, yet information on DMA removal by drinking water biofilter is still lacking. In this study, microcosms with different treatments were constructed to investigate the potential of DMA removal by a mixed culture enriched from a drinking water biofilter and the effects of carbon and nitrogen sources. DMA could be quickly mineralized by the enrichment culture. Amendment of a carbon source, instead of a nitrogen source, had a profound impact on DMA removal. A shift in bacterial community structure was observed with DMA biodegradation, affected by carbon and nitrogen sources. Proteobacteria was the predominant phylum group in DMA-degrading microcosms. Microorganisms from a variety of bacterial genera might be responsible for the rapid DMA mineralization.

  12. A theoretical study of hydrated molecular clusters of amines and dicarboxylic acids

    NASA Astrophysics Data System (ADS)

    Xu, Wen; Zhang, Renyi

    2013-08-01

    Amines and carboxylic acids have been recognized as important precursor species in atmospheric new particle formation. In this study, the interaction between dimethylamine and succinic acid is investigated using Basin Paving Monte Carlo (BPMC) sampling with the classical force field to obtain low energy conformers of dimethylamine and succinic acid hydrated molecular clusters. Geometry optimization and frequency calculations are further performed on the basis of the BPMC results using density functional theory. At standard temperature and pressure, dimethylamine binds to succinic acid with a bonding energy of 14.2 kcal mol-1, smaller than that of dimethylamine with sulfuric acid (21.1 kcal mol-1). Hydration promotes proton transfer from succinic acid to dimethylamine and consequently increases the interaction strength, while proton transfer from sulfuric acid to dimethylamine occurs without hydration. On the other hand, the reactivity of sulfuric acid with dimethylamine decreases with the degree of hydration of sulfuric acid. The free energies of formation for hydrated clusters consisting of dimethylamine and succinic acid reveal that the interaction between amines and dicarboxylic acids likely exerts a synergetic effect on atmospheric aerosol nucleation by formation of aminium carboxylate ion pairs.

  13. Putative ammonia-oxidizing bacteria and archaea in an acidic red soil with different land utilization patterns.

    PubMed

    Ying, Jiao-Yan; Zhang, Li-Mei; He, Ji-Zheng

    2010-04-01

    Ammonia-oxidizers play a key role in nitrification, which is important for nitrogen cycling and soil function. However, little is known about how vegetation successions and agricultural practices caused by human activities impact the ammonia-oxidizers and nitrification process. Putative ammonia-oxidizing bacteria (AOB) and archaea (AOA) communities under different land utilization patterns of restoration (forest), degradation (pasture), cropland and pine plantation were analysed in an acidic red soil based on bacterial and archaeal amoA genes together with archaeal 16S rRNA gene. Real-time PCR, terminal restriction fragment length polymorphism (T-RFLP) and sequencing of clone libraries were conducted to study their abundance and community structure. Land utilization pattern showed significant effects on the copy numbers of all these genes, but only the bacterial amoA gene correlated significantly with potential nitrification rates (PNR). The cropland plot possessed the highest bacterial amoA gene copies and PNR, while the degradation plot was opposite to that. There were no significant variations in the bacterial amoA gene structure, which was dominated by Clusters 10 and 11 in Nitrosospira. However, archaeal amoA gene structure varied among different land utilization patterns especially for the cropland. The degradation plot was dominated by Crenarchaea 1.1c-related groups from which the amoA gene could not been amplified in this study, while other plots were dominated by Crenarchaea 1.1a/b group based on archaeal 16S rRNA gene analysis. These results indicated significant effects of land utilization patterns on putative ammonia oxidizers, which were especially obvious in the degradation and cropland plots where frequent human disturbance occurred.

  14. On the composition of ammonia-sulfuric-acid ion clusters during aerosol particle formation

    NASA Astrophysics Data System (ADS)

    Schobesberger, S.; Franchin, A.; Bianchi, F.; Rondo, L.; Duplissy, J.; Kürten, A.; Ortega, I. K.; Metzger, A.; Schnitzhofer, R.; Almeida, J.; Amorim, A.; Dommen, J.; Dunne, E. M.; Ehn, M.; Gagné, S.; Ickes, L.; Junninen, H.; Hansel, A.; Kerminen, V.-M.; Kirkby, J.; Kupc, A.; Laaksonen, A.; Lehtipalo, K.; Mathot, S.; Onnela, A.; Petäjä, T.; Riccobono, F.; Santos, F. D.; Sipilä, M.; Tomé, A.; Tsagkogeorgas, G.; Viisanen, Y.; Wagner, P. E.; Wimmer, D.; Curtius, J.; Donahue, N. M.; Baltensperger, U.; Kulmala, M.; Worsnop, D. R.

    2015-01-01

    The formation of particles from precursor vapors is an important source of atmospheric aerosol. Research at the Cosmics Leaving OUtdoor Droplets (CLOUD) facility at CERN tries to elucidate which vapors are responsible for this new-particle formation, and how in detail it proceeds. Initial measurement campaigns at the CLOUD stainless-steel aerosol chamber focused on investigating particle formation from ammonia (NH3) and sulfuric acid (H2SO4). Experiments were conducted in the presence of water, ozone and sulfur dioxide. Contaminant trace gases were suppressed at the technological limit. For this study, we mapped out the compositions of small NH3-H2SO4 clusters over a wide range of atmospherically relevant environmental conditions. We covered [NH3] in the range from < 2 to 1400 pptv, [H2SO4] from 3.3 × 106 to 1.4 × 109 cm-3 (0.1 to 56 pptv), and a temperature range from -25 to +20 °C. Negatively and positively charged clusters were directly measured by an atmospheric pressure interface time-of-flight (APi-TOF) mass spectrometer, as they initially formed from gas-phase NH3 and H2SO4, and then grew to larger clusters containing more than 50 molecules of NH3 and H2SO4, corresponding to mobility-equivalent diameters greater than 2 nm. Water molecules evaporate from these clusters during sampling and are not observed. We found that the composition of the NH3-H2SO4 clusters is primarily determined by the ratio of gas-phase concentrations [NH3] / [H2SO4], as well as by temperature. Pure binary H2O-H2SO4 clusters (observed as clusters of only H2SO4) only form at [NH3] / [H2SO4] < 0.1 to 1. For larger values of [NH3] / [H2SO4], the composition of NH3-H2SO4 clusters was characterized by the number of NH3 molecules m added for each added H2SO4 molecule n (Δm/Δ n), where n is in the range 4-18 (negatively charged clusters) or 1-17 (positively charged clusters). For negatively charged clusters, Δ m/Δn saturated between 1 and 1.4 for [NH3] / [H2SO4] > 10. Positively

  15. On the composition of ammonia-sulfuric acid clusters during aerosol particle formation

    NASA Astrophysics Data System (ADS)

    Schobesberger, S.; Franchin, A.; Bianchi, F.; Rondo, L.; Duplissy, J.; Kürten, A.; Ortega, I. K.; Metzger, A.; Schnitzhofer, R.; Almeida, J.; Amorim, A.; Dommen, J.; Dunne, E. M.; Ehn, M.; Gagné, S.; Ickes, L.; Junninen, H.; Hansel, A.; Kerminen, V.-M.; Kirkby, J.; Kupc, A.; Laaksonen, A.; Lehtipalo, K.; Mathot, S.; Onnela, A.; Petäjä, T.; Riccobono, F.; Santos, F. D.; Sipilä, M.; Tomé, A.; Tsagkogeorgas, G.; Viisanen, Y.; Wagner, P. E.; Wimmer, D.; Curtius, J.; Donahue, N. M.; Baltensperger, U.; Kulmala, M.; Worsnop, D. R.

    2014-05-01

    The formation of particles from precursor vapors is an important source of atmospheric aerosol. Research at the Cosmics Leaving OUtdoor Droplets (CLOUD) facility at CERN tries to elucidate which vapors are responsible for this new particle formation, and how in detail it proceeds. Initial measurement campaigns at the CLOUD stainless-steel aerosol chamber focused on investigating particle formation from ammonia (NH3) and sulfuric acid (H2SO4). Experiments were conducted in the presence of water, ozone and sulfur dioxide. Contaminant trace gases were suppressed at the technological limit. For this study, we mapped out the compositions of small NH3-H2SO4 clusters over a wide range of atmospherically relevant environmental conditions. We covered [NH3] in the range from <2 to 1400 pptv, [H2SO4] from 3.3 × 106 to 1.4 × 109 cm-3, and a temperature range from -25 to +20 °C. Negatively and positively charged clusters were directly measured by an atmospheric pressure interface time-of-flight (APi-TOF) mass spectrometer, as they initially formed from gas-phase NH3 and H2SO4, and then grew to larger clusters containing more than 50 molecules of NH3 and H2SO4, corresponding to mobility-equivalent diameters greater than 2 nm. Water molecules evaporate from these clusters during sampling and are not observed. We found that the composition of the NH3-H2SO4 clusters is primarily determined by the ratio of gas-phase concentrations [NH3] / [H2SO4], as well as by temperature. Pure binary H2O-H2SO4 clusters (observed as clusters of only H2SO4) only form at [NH3] / [H2SO4]<0.1 to 1. For larger values of [NH3] / [H2SO4], the composition of NH3-H2SO4 clusters was characterized by the number of NH3 molecules m added for each added H2SO4 molecule n (Δm / Δn), where n is in the range 4-18 (negatively charged clusters) or 1-17 (positively charged clusters). For negatively charged clusters, Δm / Δn saturated between 1 and 1.4 for [NH3] / [H2SO4]>10. Positively charged clusters grew on

  16. Effect of lauric acid and coconut oil on ruminal fermentation, digestion, ammonia losses from manure, and milk fatty acid composition in lactating cows.

    PubMed

    Hristov, A N; Vander Pol, M; Agle, M; Zaman, S; Schneider, C; Ndegwa, P; Vaddella, V K; Johnson, K; Shingfield, K J; Karnati, S K R

    2009-11-01

    This experiment (replicated 3 x 3 Latin square design) was conducted to investigate the effects of lauric acid (LA) or coconut oil (CO) on ruminal fermentation, nutrient digestibility, ammonia losses from manure, and milk fatty acid (FA) composition in lactating cows. Treatments consisted of intraruminal doses of 240 g of stearic acid/d (SA; control), 240 g of LA/d, or 530 g of CO/d administered once daily, before feeding. Between periods, cows were inoculated with ruminal contents from donor cows and allowed a 7-d recovery period. Treatment did not affect dry matter intake, milk yield, or milk composition. Ruminal pH was slightly increased by CO compared with the other treatments, whereas LA and CO decreased ruminal ammonia concentration compared with SA. Both LA and CO decreased protozoal counts by 80% or more compared with SA. Methane production rate in the rumen was reduced by CO compared with LA and SA, with no differences between LA and SA. Treatments had no effect on total tract apparent dry matter, organic matter, N, and neutral detergent fiber digestibility coefficients or on cumulative (15 d) in vitro ammonia losses from manure. Compared with SA, LA and CO increased milk fat 12:0, cis-9 12:1, and trans-9 12:1 content and decreased 6:0, 8:0, 10:0, cis-9 10:1, 16:0, 18:0, cis 18:1, total 18:2, 18:3 n-3 and total polyunsaturated FA concentrations. Administration of LA and 14:0 (as CO) in the rumen were apparently transferred into milk fat with a mean efficiency of 18 and 15%, respectively. In conclusion, current data confirmed that LA and CO exhibit strong antiprotozoal activity when dosed intraruminally, an effect that is accompanied by decreases in ammonia concentration and, for CO, lowered methane production. Administration of LA and CO in the rumen also altered milk FA composition. PMID:19841218

  17. Apparatus for purifying arsine, phosphine, ammonia, and inert gases to remove Lewis acid and oxidant impurities therefrom

    DOEpatents

    Tom, Glenn M.; Brown, Duncan W.

    1991-01-08

    An apparatus for purifying a gaseous mixture comprising arsine, phosphine, ammonia, and/or inert gases, to remove Lewis acid and/or oxidant impurities therefrom, comprising a vessel containing a bed of a scavenger, the scavenger including a support having associated therewith an anion which is effective to remove such impurities, such anion being selected from one or more members of the group consisting of: (i) carbanions whose corresponding protonated compounds have a pK.sub.a value of from about 22 to about 36; and (ii) anions formed by reaction of such carbanions with the primary component of the mixture.

  18. Nitrogen metabolism, acid-base regulation, and molecular responses to ammonia and acid infusions in the spiny dogfish shark (Squalus acanthias).

    PubMed

    Nawata, C Michele; Walsh, Patrick J; Wood, Chris M

    2015-07-01

    Although they are ureotelic, marine elasmobranchs express Rh glycoproteins, putative ammonia channels. To address questions raised by a recent study on high environmental ammonia (HEA) exposure, dogfish were intravascularly infused for 24 h at 3 ml kg(-1) h(-1) with isosmotic NaCl (500 mmol l(-1), control), NH4HCO3 (500 mmol l(-1)), NH4Cl (500 mmol l(-1)), or HCl (as 125 mmol l(-1) HCl + 375 mmol l(-1) NaCl). While NaCl had no effect on arterial acid-base status, NH4HCO3 caused mild alkalosis, NH4Cl caused strong acidosis, and HCl caused lesser acidosis, all predominantly metabolic in nature. Total plasma ammonia (T(Amm)) and excretion rates of ammonia (J(Amm)) and urea-N (J(Urea-N)) were unaffected by NaCl or HCl. However, despite equal loading rates, plasma T(Amm) increased to a greater extent with NH4Cl, while J(Amm) increased to a greater extent with NH4HCO3 due to much greater increases in blood-to-water PNH3 gradients. As with HEA, both treatments caused large (90%) elevations of J(Urea-N), indicating that urea-N synthesis by the ornithine-urea cycle (OUC) is driven primarily by ammonia rather than HCO3(-). Branchial mRNA expressions of Rhbg and Rhp2 were unaffected by NH4HCO3 or NH4Cl, but v-type H(+)-ATPase was down-regulated by both treatments, and Rhbg and Na(+)/H(+) exchanger NHE2 were up-regulated by HCl. In the kidney, Rhbg was unresponsive to all treatments, but Rhp2 was up-regulated by HCl, and the urea transporter UT was up-regulated by HCl and NH4Cl. These responses are discussed in the context of current ideas about branchial, renal, and OUC function in this nitrogen-limited predator. PMID:25794843

  19. Nitrogen metabolism, acid-base regulation, and molecular responses to ammonia and acid infusions in the spiny dogfish shark (Squalus acanthias).

    PubMed

    Nawata, C Michele; Walsh, Patrick J; Wood, Chris M

    2015-07-01

    Although they are ureotelic, marine elasmobranchs express Rh glycoproteins, putative ammonia channels. To address questions raised by a recent study on high environmental ammonia (HEA) exposure, dogfish were intravascularly infused for 24 h at 3 ml kg(-1) h(-1) with isosmotic NaCl (500 mmol l(-1), control), NH4HCO3 (500 mmol l(-1)), NH4Cl (500 mmol l(-1)), or HCl (as 125 mmol l(-1) HCl + 375 mmol l(-1) NaCl). While NaCl had no effect on arterial acid-base status, NH4HCO3 caused mild alkalosis, NH4Cl caused strong acidosis, and HCl caused lesser acidosis, all predominantly metabolic in nature. Total plasma ammonia (T(Amm)) and excretion rates of ammonia (J(Amm)) and urea-N (J(Urea-N)) were unaffected by NaCl or HCl. However, despite equal loading rates, plasma T(Amm) increased to a greater extent with NH4Cl, while J(Amm) increased to a greater extent with NH4HCO3 due to much greater increases in blood-to-water PNH3 gradients. As with HEA, both treatments caused large (90%) elevations of J(Urea-N), indicating that urea-N synthesis by the ornithine-urea cycle (OUC) is driven primarily by ammonia rather than HCO3(-). Branchial mRNA expressions of Rhbg and Rhp2 were unaffected by NH4HCO3 or NH4Cl, but v-type H(+)-ATPase was down-regulated by both treatments, and Rhbg and Na(+)/H(+) exchanger NHE2 were up-regulated by HCl. In the kidney, Rhbg was unresponsive to all treatments, but Rhp2 was up-regulated by HCl, and the urea transporter UT was up-regulated by HCl and NH4Cl. These responses are discussed in the context of current ideas about branchial, renal, and OUC function in this nitrogen-limited predator.

  20. Reduction of nitrogen oxides with catalytic acid resistant aluminosilicate molecular sieves and ammonia

    DOEpatents

    Pence, Dallas T.; Thomas, Thomas R.

    1980-01-01

    Noxious nitrogen oxides in a waste gas stream such as the stack gas from a fossil-fuel-fired power generation plant or other industrial plant off-gas stream is catalytically reduced to elemental nitrogen and/or innocuous nitrogen oxides employing ammonia as reductant in the presence of a zeolite catalyst in the hydrogen or sodium form having pore openings of about 3 to 10 A.

  1. Sulfuric acid nucleation: An experimental study of the effect of seven bases

    NASA Astrophysics Data System (ADS)

    Glasoe, W. A.; Volz, K.; Panta, B.; Freshour, N.; Bachman, R.; Hanson, D. R.; McMurry, P. H.; Jen, C.

    2015-03-01

    Nucleation of particles with sulfuric acid, water, and nitrogeneous bases was studied in a flow reactor. Sulfuric acid and water levels were set by flows over sulfuric acid and water reservoirs, respectively, and the base concentrations were determined from measured permeation rates and flow dilution ratios. Particle number distributions were measured with a nano-differential-mobility-analyzer system. Results indicate that the nucleation capability of NH3, methylamine, dimethylamine, and trimethylamine with sulfuric acid increases from NH3 as the weakest, methylamine next, and dimethylamine and trimethylamine the strongest. Three other bases were studied, and experiments with triethylamine showed that it is less effective than methylamine, and experiments with urea and acetamide showed that their capabilities are much lower than the amines with acetamide having basically no effect. When both NH3 and an amine were present, nucleation was more strongly enhanced than with just the amine present. Comparisons of nucleation rates to predictions and previous experimental work are discussed, and the sulfuric acid-base nucleation rates measured here are extrapolated to atmospheric conditions. The measurements suggest that atmospheric nucleation rates are significantly affected by synergistic interactions between ammonia and amines.

  2. Conversion of upland to paddy field specifically alters the community structure of archaeal ammonia oxidizers in an acid soil

    NASA Astrophysics Data System (ADS)

    Alam, M. S.; Ren, G. D.; Lu, L.; Zheng, Y.; Peng, X. H.; Jia, Z. J.

    2013-08-01

    The function of ammonia-oxidizing archaea (AOA) and bacteria (AOB) depends on the major energy-generating compounds (i.e., ammonia and oxygen). The diversification of AOA and AOB communities along ecological gradients of substrate availability in a complex environment have been much debated but rarely tested. In this study, two ecosystems of maize and rice crops under different fertilization regimes were selected to investigate the community diversification of soil AOA and AOB upon conversion of an upland field to a paddy field and long-term field fertilization in an acid soil. Real-time quantitative polymerase chain reaction of ammonia monooxygenase (amoA) genes demonstrated that the abundance of AOA was significantly stimulated after conversion of upland to paddy soils for more than 100 yr, whereas a slight decline in AOB numbers was observed. Denaturing gradient gel electrophoresis fingerprints of amoA genes further revealed remarkable changes in the community compositions of AOA after conversion of aerobic upland to flooded paddy field. Sequencing analysis revealed that upland soil was dominated by AOA within the soil group 1.1b lineage, whereas the marine group 1.1a-associated lineage predominated in AOA communities in paddy soils. Irrespective of whether the soil was upland or paddy soil, long-term field fertilization led to increased abundance of amoA genes in AOA and AOB compared with control treatments (no fertilization), whereas archaeal amoA gene abundances outnumbered their bacterial counterparts in all samples. Phylogenetic analyses of amoA genes showed that Nitrosospira cluster-3-like AOB dominated bacterial ammonia oxidizers in both paddy and upland soils, regardless of fertilization treatment. The results of this study suggest that the marine group 1.1a-associated AOA will be better adapted to the flooded paddy field than AOA ecotypes of the soil group 1.1b lineage, and indicate that long-term flooding is the dominant selective force driving the

  3. Insight into acid-base nucleation experiments by comparison of the chemical composition of positive, negative, and neutral clusters.

    PubMed

    Bianchi, Federico; Praplan, Arnaud P; Sarnela, Nina; Dommen, Josef; Kürten, Andreas; Ortega, Ismael K; Schobesberger, Siegfried; Junninen, Heikki; Simon, Mario; Tröstl, Jasmin; Jokinen, Tuija; Sipilä, Mikko; Adamov, Alexey; Amorim, Antonio; Almeida, Joao; Breitenlechner, Martin; Duplissy, Jonathan; Ehrhart, Sebastian; Flagan, Richard C; Franchin, Alessandro; Hakala, Jani; Hansel, Armin; Heinritzi, Martin; Kangasluoma, Juha; Keskinen, Helmi; Kim, Jaeseok; Kirkby, Jasper; Laaksonen, Ari; Lawler, Michael J; Lehtipalo, Katrianne; Leiminger, Markus; Makhmutov, Vladimir; Mathot, Serge; Onnela, Antti; Petäjä, Tuukka; Riccobono, Francesco; Rissanen, Matti P; Rondo, Linda; Tomé, António; Virtanen, Annele; Viisanen, Yrjö; Williamson, Christina; Wimmer, Daniela; Winkler, Paul M; Ye, Penglin; Curtius, Joachim; Kulmala, Markku; Worsnop, Douglas R; Donahue, Neil M; Baltensperger, Urs

    2014-12-01

    We investigated the nucleation of sulfuric acid together with two bases (ammonia and dimethylamine), at the CLOUD chamber at CERN. The chemical composition of positive, negative, and neutral clusters was studied using three Atmospheric Pressure interface-Time Of Flight (APi-TOF) mass spectrometers: two were operated in positive and negative mode to detect the chamber ions, while the third was equipped with a nitrate ion chemical ionization source allowing detection of neutral clusters. Taking into account the possible fragmentation that can happen during the charging of the ions or within the first stage of the mass spectrometer, the cluster formation proceeded via essentially one-to-one acid-base addition for all of the clusters, independent of the type of the base. For the positive clusters, the charge is carried by one excess protonated base, while for the negative clusters it is carried by a deprotonated acid; the same is true for the neutral clusters after these have been ionized. During the experiments involving sulfuric acid and dimethylamine, it was possible to study the appearance time for all the clusters (positive, negative, and neutral). It appeared that, after the formation of the clusters containing three molecules of sulfuric acid, the clusters grow at a similar speed, independent of their charge. The growth rate is then probably limited by the arrival rate of sulfuric acid or cluster-cluster collision.

  4. Insight into acid-base nucleation experiments by comparison of the chemical composition of positive, negative, and neutral clusters.

    PubMed

    Bianchi, Federico; Praplan, Arnaud P; Sarnela, Nina; Dommen, Josef; Kürten, Andreas; Ortega, Ismael K; Schobesberger, Siegfried; Junninen, Heikki; Simon, Mario; Tröstl, Jasmin; Jokinen, Tuija; Sipilä, Mikko; Adamov, Alexey; Amorim, Antonio; Almeida, Joao; Breitenlechner, Martin; Duplissy, Jonathan; Ehrhart, Sebastian; Flagan, Richard C; Franchin, Alessandro; Hakala, Jani; Hansel, Armin; Heinritzi, Martin; Kangasluoma, Juha; Keskinen, Helmi; Kim, Jaeseok; Kirkby, Jasper; Laaksonen, Ari; Lawler, Michael J; Lehtipalo, Katrianne; Leiminger, Markus; Makhmutov, Vladimir; Mathot, Serge; Onnela, Antti; Petäjä, Tuukka; Riccobono, Francesco; Rissanen, Matti P; Rondo, Linda; Tomé, António; Virtanen, Annele; Viisanen, Yrjö; Williamson, Christina; Wimmer, Daniela; Winkler, Paul M; Ye, Penglin; Curtius, Joachim; Kulmala, Markku; Worsnop, Douglas R; Donahue, Neil M; Baltensperger, Urs

    2014-12-01

    We investigated the nucleation of sulfuric acid together with two bases (ammonia and dimethylamine), at the CLOUD chamber at CERN. The chemical composition of positive, negative, and neutral clusters was studied using three Atmospheric Pressure interface-Time Of Flight (APi-TOF) mass spectrometers: two were operated in positive and negative mode to detect the chamber ions, while the third was equipped with a nitrate ion chemical ionization source allowing detection of neutral clusters. Taking into account the possible fragmentation that can happen during the charging of the ions or within the first stage of the mass spectrometer, the cluster formation proceeded via essentially one-to-one acid-base addition for all of the clusters, independent of the type of the base. For the positive clusters, the charge is carried by one excess protonated base, while for the negative clusters it is carried by a deprotonated acid; the same is true for the neutral clusters after these have been ionized. During the experiments involving sulfuric acid and dimethylamine, it was possible to study the appearance time for all the clusters (positive, negative, and neutral). It appeared that, after the formation of the clusters containing three molecules of sulfuric acid, the clusters grow at a similar speed, independent of their charge. The growth rate is then probably limited by the arrival rate of sulfuric acid or cluster-cluster collision. PMID:25406110

  5. Sol-gel process for preparation of YBa{sub 2}Cu{sub 4}O{sub 8} from acidic acetates/ammonia/ascorbic acid systems

    SciTech Connect

    Deptula, A.; Lada, W.; Olczak, T.; Goretta, K.C.; Bartolomeo, A.; Casadio, S.

    1997-03-01

    YBa{sub 2}Cu{sub 4}O{sub x} sols were prepared by addition of ammonia to acidic acetate solutions of Y{sup 3+}, Ba{sup 2+}, and Cu{sup 2+}. Ascorbic acid was added to part of the sol. The resultant sols were gelled to a shard or a coating by evaporation at 60 C. Addition of ethanol to the sols facilitated formation of gel coatings, fabricated by a dipping technique, on Ag or glass or substrates. At 100 C, gels formed in the presence of ascorbic acid were perfectly amorphous, in contrast to crystalline acetate gels. The quality of coatings prepared from ascorbate gels was superior to that of acetate gel coatings.

  6. Formation rates, stability and reactivity of sulfuric acid - amine clusters predicted by computational chemistry

    NASA Astrophysics Data System (ADS)

    Kurtén, Theo; Ortega, Ismael; Kupiainen, Oona; Olenius, Tinja; Loukonen, Ville; Reiman, Heidi; McGrath, Matthew; Vehkamäki, Hanna

    2013-04-01

    Despite the importance of atmospheric particle formation for both climate and air quality, both experiments and non-empirical models using e.g. sulfuric acid, ammonia and water as condensing vapors have so far been unable to reproduce atmospheric observations using realistic trace gas concentrations. Recent experimental and theoretical evidence has shown that this mystery is likely resolved by amines. Combining first-principles evaporation rates for sulfuric acid - dimethylamine clusters with cluster kinetic modeling, we show that even sub-ppt concentrations of amines, together with atmospherically realistic concentrations of sulfuric acid, result in formation rates close to those observed in the atmosphere. Our simulated cluster formation rates are also close to, though somewhat larger than, those measured at the CLOUD experiment in CERN for both sulfuric acid - ammonia and sulfuric acid - dimethylamine systems. A sensitivity analysis indicates that the remaining discrepancy for the sulfuric acid - amine particle formation rates is likely caused by steric hindrances to cluster formation (due to alkyl groups of the amine molecules) rather than by significant errors in the evaporation rates. First-principles molecular dynamic and reaction kinetic modeling shed further light on the microscopic physics and chemistry of sulfuric acid - amine clusters. For example, while the number and type of hydrogen bonds in the clusters typically reach their equilibrium values on a picosecond timescale, and the overall bonding patterns predicted by traditional "static" quantum chemical calculations seem to be stable, the individual atoms participating in the hydrogen bonds continuously change at atmospherically realistic temperatures. From a chemical reactivity perspective, we have also discovered a surprising phenomenon: clustering with sulfuric acid molecules slightly increases the activation energy required for the abstraction of alkyl hydrogens from amine molecules. This implies

  7. Removal of volatile fatty acids and ammonia recovery from unstable anaerobic digesters with a microbial electrolysis cell.

    PubMed

    Cerrillo, Míriam; Viñas, Marc; Bonmatí, August

    2016-11-01

    Continuous assays with a microbial electrolysis cell (MEC) fed with digested pig slurry were performed to evaluate its stability and robustness to malfunction periods of an anaerobic digestion (AD) reactor and its feasibility as a strategy to recover ammonia. When performing punctual pulses of volatile fatty acids (VFA) in the anode compartment of the MEC, simulating a malfunction of the AD process, an increase in the current density was produced (up to 14 times, reaching values of 3500mAm(-2)) as a result of the added chemical oxygen demand (COD), especially when acetate was used. Furthermore, ammonium diffusion from the anode to the cathode compartment was enhanced and the removal efficiency achieved up to 60% during daily basis VFA pulses. An AD-MEC combined system has proven to be a robust and stable configuration to obtain a high quality effluent, with a lower organic and ammonium content. PMID:27501031

  8. Tropospheric Emission Spectrometer (TES) satellite observations of ammonia, methanol, formic acid, and carbon monoxide over the Canadian oil sands: validation and model evaluation

    EPA Science Inventory

    The wealth of air quality information provided by satellite infrared observations of ammonia (NH3), carbon monoxide (CO), formic acid (HCOOH), and methanol (CH3OH) is currently being explored and used for a number of applications, especially at regional or global scales. These ap...

  9. Production of fermentable sugars from corn fiber using soaking in aqueous ammonia (saa) pretreatment and fermentation to succinic acid by Escherichia coli afp184

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Conversion of corn fiber (CF), a by-product from the corn-to-ethanol conversion process, into fermentable sugar and succinic acid was investigated using soaking in aqueous ammonia (SAA) pretreatment followed by biological conversions including enzymatic hydrolysis and fermentation using genetically ...

  10. The effect of acid-base clustering and ions on the growth of atmospheric nano-particles

    NASA Astrophysics Data System (ADS)

    Lehtipalo, Katrianne; Rondo, Linda; Kontkanen, Jenni; Schobesberger, Siegfried; Jokinen, Tuija; Sarnela, Nina; Kürten, Andreas; Ehrhart, Sebastian; Franchin, Alessandro; Nieminen, Tuomo; Riccobono, Francesco; Sipilä, Mikko; Yli-Juuti, Taina; Duplissy, Jonathan; Adamov, Alexey; Ahlm, Lars; Almeida, João; Amorim, Antonio; Bianchi, Federico; Breitenlechner, Martin; Dommen, Josef; Downard, Andrew J.; Dunne, Eimear M.; Flagan, Richard C.; Guida, Roberto; Hakala, Jani; Hansel, Armin; Jud, Werner; Kangasluoma, Juha; Kerminen, Veli-Matti; Keskinen, Helmi; Kim, Jaeseok; Kirkby, Jasper; Kupc, Agnieszka; Kupiainen-Määttä, Oona; Laaksonen, Ari; Lawler, Michael J.; Leiminger, Markus; Mathot, Serge; Olenius, Tinja; Ortega, Ismael K.; Onnela, Antti; Petäjä, Tuukka; Praplan, Arnaud; Rissanen, Matti P.; Ruuskanen, Taina; Santos, Filipe D.; Schallhart, Simon; Schnitzhofer, Ralf; Simon, Mario; Smith, James N.; Tröstl, Jasmin; Tsagkogeorgas, Georgios; Tomé, António; Vaattovaara, Petri; Vehkamäki, Hanna; Vrtala, Aron E.; Wagner, Paul E.; Williamson, Christina; Wimmer, Daniela; Winkler, Paul M.; Virtanen, Annele; Donahue, Neil M.; Carslaw, Kenneth S.; Baltensperger, Urs; Riipinen, Ilona; Curtius, Joachim; Worsnop, Douglas R.; Kulmala, Markku

    2016-05-01

    The growth of freshly formed aerosol particles can be the bottleneck in their survival to cloud condensation nuclei. It is therefore crucial to understand how particles grow in the atmosphere. Insufficient experimental data has impeded a profound understanding of nano-particle growth under atmospheric conditions. Here we study nano-particle growth in the CLOUD (Cosmics Leaving OUtdoors Droplets) chamber, starting from the formation of molecular clusters. We present measured growth rates at sub-3 nm sizes with different atmospherically relevant concentrations of sulphuric acid, water, ammonia and dimethylamine. We find that atmospheric ions and small acid-base clusters, which are not generally accounted for in the measurement of sulphuric acid vapour, can participate in the growth process, leading to enhanced growth rates. The availability of compounds capable of stabilizing sulphuric acid clusters governs the magnitude of these effects and thus the exact growth mechanism. We bring these observations into a coherent framework and discuss their significance in the atmosphere.

  11. Theoretical Modeling of Formic Acid (HCOOH), Formate (HCOO(-)), and Ammonia (NH(4)) Vibrational Spectra in Astrophysical Ices

    NASA Technical Reports Server (NTRS)

    Park, Jin-Young; Woon, David E.

    2006-01-01

    Ions embedded in icy grain mantles are thought to account for various observed infrared spectroscopic features, particularly in certain young stellar objects. The dissociation of formic acid (HCOOH) in astrophysical ices to form the formate ion (HCOO(-)) was modeled with density functional theory cluster calculations. Like isocyanic acid (HOCN), HCOOH was found to spontaneously deprotonate when sufficient water is present to stabilize charge transfer complexes. Both ammonia and water can serve as proton acceptors, yielding ammonium (NH4(+)) and hydronium (H3O(+)) counterions. Computed frequencies of weak infrared features produced by stretching and bending modes in both HCOO(-) and HCOOH were compared with experimental and astronomical data. Our results confirm laboratory assignments that a band at 1381 cm(exp -1) can be attributed to the CH bend in either HCOO(-) or HCOOH, but a band at 1349 cm(exp -1) corresponds to CO stretching in HCOO(-). Another feature at 1710 cm(exp -1) (5.85 m) can possibly be assigned to a CO stretching mode in HCOOH, as suggested by experiment, but the agreement is less satisfactory. In addition, we examine and analyze spectroscopic features associated with NH+4, both as a counterion to HCOO(-) or OCN(-) and in isolation, in order to compare with experimental and astronomical data in the 7 m region.

  12. Comparison of epichlorohydrin-dimethylamine with other cationic organic polymers as coagulation aids of polyferric chloride in coagulation-ultrafiltration process.

    PubMed

    Sun, Shenglei; Gao, Baoyu; Yue, Qinyan; Li, Ruihua; Song, Wen; Bu, Fan; Zhao, Shuang; Jia, Ruibao; Song, Wuchang

    2016-04-15

    Epichlorohydrin-dimethylamine (DAM-ECH) copolymer was acquired by polycondensation of hazardous reagents: epichlorohydrin (analytical reagent, A.R.) and dimethylamine (A.R.) with ethanediamine (A.R.) as cross-linker. Its coagulation and membrane performance as coagulation aid of polyferric chloride (PFC) was evaluated by comparing with other two cationic coagulation aids: poly dimethyl diallyl ammonium chloride (PDMDAAC) and polyacrylamide (PAM) in humic acid-kaolin (HA-Kaolin) simulated water treatment. Firstly, optimum dosages of PFC&DAM-ECH, PFC&PDMDAAC and PFC&PAM were identified according to their coagulation performance. Then their impacts (under optimum dosages) on membrane fouling of regenerated cellulose (RC) ultra-membrane disc in coagulation-ultrafiltration (C-UF) process were reviewed. Results revealed that small addition of DAM-ECH was the effective on turbidity and DOC removal polymer. Furthermore, in the following ultra-filtration process, external membrane fouling resistance was demonstrated to be the dominant portion of the total membrane fouling resistance under all circumstances. Meanwhile, the internal membrane fouling resistance was determined by residual of micro-particles(1) that cannot be intercepted by cake layer or ultrafiltration membrane.

  13. Comparison of epichlorohydrin-dimethylamine with other cationic organic polymers as coagulation aids of polyferric chloride in coagulation-ultrafiltration process.

    PubMed

    Sun, Shenglei; Gao, Baoyu; Yue, Qinyan; Li, Ruihua; Song, Wen; Bu, Fan; Zhao, Shuang; Jia, Ruibao; Song, Wuchang

    2016-04-15

    Epichlorohydrin-dimethylamine (DAM-ECH) copolymer was acquired by polycondensation of hazardous reagents: epichlorohydrin (analytical reagent, A.R.) and dimethylamine (A.R.) with ethanediamine (A.R.) as cross-linker. Its coagulation and membrane performance as coagulation aid of polyferric chloride (PFC) was evaluated by comparing with other two cationic coagulation aids: poly dimethyl diallyl ammonium chloride (PDMDAAC) and polyacrylamide (PAM) in humic acid-kaolin (HA-Kaolin) simulated water treatment. Firstly, optimum dosages of PFC&DAM-ECH, PFC&PDMDAAC and PFC&PAM were identified according to their coagulation performance. Then their impacts (under optimum dosages) on membrane fouling of regenerated cellulose (RC) ultra-membrane disc in coagulation-ultrafiltration (C-UF) process were reviewed. Results revealed that small addition of DAM-ECH was the effective on turbidity and DOC removal polymer. Furthermore, in the following ultra-filtration process, external membrane fouling resistance was demonstrated to be the dominant portion of the total membrane fouling resistance under all circumstances. Meanwhile, the internal membrane fouling resistance was determined by residual of micro-particles(1) that cannot be intercepted by cake layer or ultrafiltration membrane. PMID:26775103

  14. Ammonia Monitor

    NASA Technical Reports Server (NTRS)

    Sauer, Richard L. (Inventor); Akse, James R. (Inventor); Thompson, John O. (Inventor); Atwater, James E. (Inventor)

    1999-01-01

    Ammonia monitor and method of use are disclosed. A continuous, real-time determination of the concentration of ammonia in an aqueous process stream is possible over a wide dynamic range of concentrations. No reagents are required because pH is controlled by an in-line solid-phase base. Ammonia is selectively transported across a membrane from the process stream to an analytical stream to an analytical stream under pH control. The specific electrical conductance of the analytical stream is measured and used to determine the concentration of ammonia.

  15. The measurement of ammonia blood levels in patients taking valproic acid: looking for problems where they do not exist?

    PubMed

    Chicharro, Ada V; de Marinis, Alejandro J; Kanner, Andres M

    2007-11-01

    Hyperammonemia (HA) commonly occurs with the use of valproic acid (VPA); while it has no clinical significance in most cases, the Physician Desk Reference recommends its discontinuation in the presence of HA. The purpose of this study is to review the literature in order to estimate the prevalence and magnitude of HA in VPA treated patients, to establish any association with hepatotoxicity and encephalopathy and to identify any factors associated with its occurrence. A search of MEDLINE and Cochrane Database of Systematic Reviews, between 1980 and 2005 was performed. Out of 183 studies, 24 met our inclusion criteria. The prevalence of HA in the prospective studies ranged between 70% and 100%, while in cross-sectional studies it varied between 16% and 100%. Ammonia (NH(3)) blood levels increased by a two-fold average relative to the baseline levels. There was no association between HA and clinical symptoms. Concomitant administration of other antiepileptic drugs (AEDs) was the factor most frequently associated with HA.

  16. Ozone, nitric acid, and ammonia air pollution is unhealthy for people and ecosystems in southern Sierra Nevada, California.

    PubMed

    Cisneros, Ricardo; Bytnerowicz, Andrzej; Schweizer, Donald; Zhong, Sharon; Traina, Samuel; Bennett, Deborah H

    2010-10-01

    Two-week average concentrations of ozone (O3), nitric acid vapor (HNO3) and ammonia (NH3) were measured with passive samplers during the 2002 summer season across the central Sierra Nevada Mountains, California, along the San Joaquin River drainage. Elevated concentrations of the pollutants were determined with seasonal means for individual sites ranging between 62 and 88 ppb for O3, 1.0-3.8 microg m(-3) for HNO3, and 2.6-5.2 microg m(-3) for NH3. Calculated O3 exposure indices were very high, reaching SUM00-191 ppm h, SUM60-151 ppm h, and W126-124 ppm h. Calculated nitrogen (N) dry deposition ranged from 1.4 to 15 kg N ha(-1) for maximum values, and 0.4-8 kg N ha(-1) for minimum values; potentially exceeding Critical Loads (CL) for nutritional N. The U.S., California, and European 8 h O3 human health standards were exceeded during 104, 108, and 114 days respectively, indicating high risk to humans from ambient O3. PMID:20708832

  17. Size-controllable APTS stabilized ruthenium(0) nanoparticles catalyst for the dehydrogenation of dimethylamine-borane at room temperature.

    PubMed

    Zahmakıran, Mehmet; Philippot, Karine; Özkar, Saim; Chaudret, Bruno

    2012-01-14

    Dimethylamine-borane, (CH(3))(2)NHBH(3), has been considered as one of the attractive materials for the efficient storage of hydrogen, which is still one of the key issues in the "Hydrogen Economy". In a recent communication we have reported the synthesis and characterization of 3-aminopropyltriethoxysilane stabilized ruthenium(0) nanoparticles with the preliminary results for their catalytic performance in the dehydrogenation of dimethylamine-borane at room temperature. Herein, we report a complete work including (i) effect of initial [APTS]/[Ru] molar ratio on both the size and the catalytic activity of ruthenium(0) nanoparticles, (ii) collection of extensive kinetic data under non-MTL conditions depending on the substrate and catalyst concentrations to define the rate law of Ru(0)/APTS-catalyzed dehydrogenation of dimethylamine-borane at room temperature, (iii) determination of activation parameters (E(a), ΔH(#) and ΔS(#)) for Ru(0)/APTS-catalyzed dehydrogenation of dimethylamine-borane; (iv) demonstration of the catalytic lifetime of Ru(0)/APTS nanoparticles in the dehydrogenation of dimethylamine-borane at room temperature, (v) testing the bottlability and reusability of Ru(0)/APTS nanocatalyst in the room-temperature dehydrogenation of dimethylamine-borane, (vi) quantitative carbon disulfide (CS(2)) poisoning experiments to find a corrected TTO and TOF values on a per-active-ruthenium-atom basis, (vii) a summary of extensive literature review for the catalysts tested in the catalytic dehydrogenation of dimethylamine-borane as part of the results and discussions. PMID:22052298

  18. Combined Flux Chamber and Genomics Approach Links Nitrous Acid Emissions to Ammonia Oxidizing Bacteria and Archaea in Urban and Agricultural Soil.

    PubMed

    Scharko, Nicole K; Schütte, Ursel M E; Berke, Andrew E; Banina, Lauren; Peel, Hannah R; Donaldson, Melissa A; Hemmerich, Chris; White, Jeffrey R; Raff, Jonathan D

    2015-12-01

    Nitrous acid (HONO) is a photochemical source of hydroxyl radical and nitric oxide in the atmosphere that stems from abiotic and biogenic processes, including the activity of ammonia-oxidizing soil microbes. HONO fluxes were measured from agricultural and urban soil in mesocosm studies aimed at characterizing biogenic sources and linking them to indigenous microbial consortia. Fluxes of HONO from agricultural and urban soil were suppressed by addition of a nitrification inhibitor and enhanced by amendment with ammonium (NH4(+)), with peaks at 19 and 8 ng m(-2) s(-1), respectively. In addition, both agricultural and urban soils were observed to convert (15)NH4(+) to HO(15)NO. Genomic surveys of soil samples revealed that 1.5-6% of total expressed 16S rRNA sequences detected belonged to known ammonia oxidizing bacteria and archaea. Peak fluxes of HONO were directly related to the abundance of ammonia-oxidizer sequences, which in turn depended on soil pH. Peak HONO fluxes under fertilized conditions are comparable in magnitude to fluxes reported during field campaigns. The results suggest that biogenic HONO emissions will be important in soil environments that exhibit high nitrification rates (e.g., agricultural soil) although the widespread occurrence of ammonia oxidizers implies that biogenic HONO emissions are also possible in the urban and remote environment.

  19. ESR studies on the thermal decomposition of trimethylamine oxide to formaldehyde and dimethylamine in jumbo squid (Dosidicus gigas) extract.

    PubMed

    Zhu, Junli; Jia, Jia; Li, Xuepeng; Dong, Liangliang; Li, Jianrong

    2013-12-15

    The effects of ferrous iron, heating temperature and different additives on the decomposition of trimethylamine oxide (TMAO) to formaldehyde (FA) and dimethylamine (DMA) and generation of free radicals in jumbo squid (Dosidicus gigas) extract during heating were evaluated by electron spin resonance (ESR). The thermal decomposition of TMAO to TMA, DMA and FA and free radical signals was observed in squid extract, whereas no DMA, FA and free radical signals were detected in cod extract or in aqueous TMAO solution in vitro at high temperatures. Significant increase in levels of DMA, FA and radicals intensity were observed in squid extract and TMAO solution in the presence of ferrous iron with increasing temperature. Hydrogen peroxide stimulated the production of DMA, FA and ESR signals in squid extract, while citric acid, trisodium citrate, calcium chloride, tea polyphenols and resveratrol had the opposite effect. Similar ESR spectra of six peaks regarded as amminium radical were detected in the squid extract and TMAO-iron(II) solution, suggesting that the amminium radical was involved in the decomposition of TMAO.

  20. Expression Analysis of Phenylalanine Ammonia Lyase Gene and Rosmarinic Acid Production in Salvia officinalis and Salvia virgata Shoots Under Salicylic Acid Elicitation.

    PubMed

    Ejtahed, Roghayeh Sadat; Radjabian, Tayebeh; Hoseini Tafreshi, Sayed Ali

    2015-08-01

    Partial fragments of phenylalanine ammonia lyase (PAL) genes were cloned and characterized from Salvia officinalis (SoPAL) and Salvia virgata (SvPAL). Different concentrations (250 and 500 μM) of exogenous salicylic acid (SA) were used when correlation between PAL expression and rosmarinic acid (RA) accumulation was compared. The results showed that the deduced cDNA sequences of the partial genes had high similarities with those of known PAL gene from other plant species. Semi-quantitative reverse transcription PCR (RT-PCR) analysis revealed that exogenous application of SA led to up-regulating of the PAL expression. Further analysis showed that in S. virgata, at higher concentration of SA, higher accumulation of RA was achieved, while in S. officinalis, the higher RA accumulation was observed at lower concentration of SA. It was concluded that there was no positive correlation between the intensity of PAL transcription and the RA accumulation in the studied species. Therefore, despite of the increase in transcription rate of the PAL at the higher concentration of SA, the lower amounts of RA were accumulated in the case of S. officinalis. Consequently, the hypothesis that PAL is the rate-determining step in RA biosynthesis is not always valid and probably some other unknown factors participate in the synthesis of phenolics.

  1. Alternative E ammonia feedstock

    SciTech Connect

    Lentz, M.J.; Wright, R.A.

    1999-07-01

    Power plants are using more Ammonia for increasing precipitator and baghouse efficiency, for SCR and SNCR processes, and for controlling acid stack plumes and dewpoint corrosion. These simple systems inject ammonia and air into the furnace or the precipitator or baghouse inlet ductwork. The common feedstocks in use today are Anhydrous ammonia [NH{sub 3}] and Aqueous ammonia [NH{sub 4}OH], both defined as poison gases by US authorities and most Western nations. Storage and handling procedures for these products are strictly regulated. Wilhelm Environmental Technologies Inc. is developing use of solid, formed or prilled Urea [CO(NH{sub 2}){sub 2}] as the feedstock. When heated in moist air, Urea sublimes to ammonia [NH{sub 3}] and carbon dioxide [CO{sub 2}]. Urea is stored and handled without restrictions or environmental concerns. Urea is a more expensive feedstock than NH{sub 3}, but much less expensive than [NH{sub 4}OH]. The design, and operating results, of a pilot system at Jacksonville Electric St. John's River Plant [Unit 2] are described. The pilot plant successfully sublimed Urea up to 100 pounds/hour. Further testing is planned. Very large ammonia use may favor NH{sub 3}, but smaller quantities can be produced at attractive prices with Urea based ammonia systems. Storage costs are far less. Many fluidized-bed boilers can use pastille or solid urea metered directly into the existing cyclones for NO{sub x} control. This is more economical than aqueous ammonia or aqueous urea based technology.

  2. Bipolar membrane electrodialysis for generation of hydrochloric acid and ammonia from simulated ammonium chloride wastewater.

    PubMed

    Li, Ya; Shi, Shaoyuan; Cao, Hongbin; Wu, Xinmin; Zhao, Zhijuan; Wang, Liying

    2016-02-01

    Simulated ammonium chloride wastewater was treated by a lab-scale bipolar membrane electrodialysis for the generation of HCl and NH3·H2O and desalination. The influence of initial concentration of NH4Cl, current density, salt solution volume, initial concentration of acid and base and membrane stack structure on the yields of HCl and NH3·H2O was investigated. The current efficiency and energy consumption were also examined under different conditions. The results showed that, at the current density of 48 mA/cm(2), the highest concentration of HCl and NH3·H2O with initial concentration of 110 g/L NH4Cl was 57.67 g/L and 45.85 g/L, respectively. Higher initial concentration of NH4Cl was favor to reduce unit energy consumption and increase current efficiency of the BMED system. The membrane stack voltage of BMED increased quickly under constant current when the concentration of NH4Cl contained in the solution of salt compartment was depleted below the "inflection point concentration" about 8000 mg/L. It means that the concentration of NH4Cl below 8000 mg/L was no longer suitable for BMED because of higher energy consumption. The HCl and NH3·H2O concentration increased more quickly following the increase of current density. When increasing the volume of NH4Cl, the concentration of HCl and NH3·H2O also increased. The high initial concentration of acid and base could improve the final concentration of them, while the growth rate was decreased. Compared with the BMED system with three compartments, the growth rate of HCl concentration with the two compartments was higher and its unit energy consumption was lower. It meant that the performance of the BMED system could be improved by optimizing operation conditions. The application feasibility of the generation of HCl and NH3·H2O and desalination of ammonium chloride wastewater by BMED was proved. PMID:26674548

  3. Bipolar membrane electrodialysis for generation of hydrochloric acid and ammonia from simulated ammonium chloride wastewater.

    PubMed

    Li, Ya; Shi, Shaoyuan; Cao, Hongbin; Wu, Xinmin; Zhao, Zhijuan; Wang, Liying

    2016-02-01

    Simulated ammonium chloride wastewater was treated by a lab-scale bipolar membrane electrodialysis for the generation of HCl and NH3·H2O and desalination. The influence of initial concentration of NH4Cl, current density, salt solution volume, initial concentration of acid and base and membrane stack structure on the yields of HCl and NH3·H2O was investigated. The current efficiency and energy consumption were also examined under different conditions. The results showed that, at the current density of 48 mA/cm(2), the highest concentration of HCl and NH3·H2O with initial concentration of 110 g/L NH4Cl was 57.67 g/L and 45.85 g/L, respectively. Higher initial concentration of NH4Cl was favor to reduce unit energy consumption and increase current efficiency of the BMED system. The membrane stack voltage of BMED increased quickly under constant current when the concentration of NH4Cl contained in the solution of salt compartment was depleted below the "inflection point concentration" about 8000 mg/L. It means that the concentration of NH4Cl below 8000 mg/L was no longer suitable for BMED because of higher energy consumption. The HCl and NH3·H2O concentration increased more quickly following the increase of current density. When increasing the volume of NH4Cl, the concentration of HCl and NH3·H2O also increased. The high initial concentration of acid and base could improve the final concentration of them, while the growth rate was decreased. Compared with the BMED system with three compartments, the growth rate of HCl concentration with the two compartments was higher and its unit energy consumption was lower. It meant that the performance of the BMED system could be improved by optimizing operation conditions. The application feasibility of the generation of HCl and NH3·H2O and desalination of ammonium chloride wastewater by BMED was proved.

  4. Molecular understanding of sulphuric acid-amine particle nucleation in the atmosphere.

    PubMed

    Almeida, João; Schobesberger, Siegfried; Kürten, Andreas; Ortega, Ismael K; Kupiainen-Määttä, Oona; Praplan, Arnaud P; Adamov, Alexey; Amorim, Antonio; Bianchi, Federico; Breitenlechner, Martin; David, André; Dommen, Josef; Donahue, Neil M; Downard, Andrew; Dunne, Eimear; Duplissy, Jonathan; Ehrhart, Sebastian; Flagan, Richard C; Franchin, Alessandro; Guida, Roberto; Hakala, Jani; Hansel, Armin; Heinritzi, Martin; Henschel, Henning; Jokinen, Tuija; Junninen, Heikki; Kajos, Maija; Kangasluoma, Juha; Keskinen, Helmi; Kupc, Agnieszka; Kurtén, Theo; Kvashin, Alexander N; Laaksonen, Ari; Lehtipalo, Katrianne; Leiminger, Markus; Leppä, Johannes; Loukonen, Ville; Makhmutov, Vladimir; Mathot, Serge; McGrath, Matthew J; Nieminen, Tuomo; Olenius, Tinja; Onnela, Antti; Petäjä, Tuukka; Riccobono, Francesco; Riipinen, Ilona; Rissanen, Matti; Rondo, Linda; Ruuskanen, Taina; Santos, Filipe D; Sarnela, Nina; Schallhart, Simon; Schnitzhofer, Ralf; Seinfeld, John H; Simon, Mario; Sipilä, Mikko; Stozhkov, Yuri; Stratmann, Frank; Tomé, Antonio; Tröstl, Jasmin; Tsagkogeorgas, Georgios; Vaattovaara, Petri; Viisanen, Yrjo; Virtanen, Annele; Vrtala, Aron; Wagner, Paul E; Weingartner, Ernest; Wex, Heike; Williamson, Christina; Wimmer, Daniela; Ye, Penglin; Yli-Juuti, Taina; Carslaw, Kenneth S; Kulmala, Markku; Curtius, Joachim; Baltensperger, Urs; Worsnop, Douglas R; Vehkamäki, Hanna; Kirkby, Jasper

    2013-10-17

    Nucleation of aerosol particles from trace atmospheric vapours is thought to provide up to half of global cloud condensation nuclei. Aerosols can cause a net cooling of climate by scattering sunlight and by leading to smaller but more numerous cloud droplets, which makes clouds brighter and extends their lifetimes. Atmospheric aerosols derived from human activities are thought to have compensated for a large fraction of the warming caused by greenhouse gases. However, despite its importance for climate, atmospheric nucleation is poorly understood. Recently, it has been shown that sulphuric acid and ammonia cannot explain particle formation rates observed in the lower atmosphere. It is thought that amines may enhance nucleation, but until now there has been no direct evidence for amine ternary nucleation under atmospheric conditions. Here we use the CLOUD (Cosmics Leaving OUtdoor Droplets) chamber at CERN and find that dimethylamine above three parts per trillion by volume can enhance particle formation rates more than 1,000-fold compared with ammonia, sufficient to account for the particle formation rates observed in the atmosphere. Molecular analysis of the clusters reveals that the faster nucleation is explained by a base-stabilization mechanism involving acid-amine pairs, which strongly decrease evaporation. The ion-induced contribution is generally small, reflecting the high stability of sulphuric acid-dimethylamine clusters and indicating that galactic cosmic rays exert only a small influence on their formation, except at low overall formation rates. Our experimental measurements are well reproduced by a dynamical model based on quantum chemical calculations of binding energies of molecular clusters, without any fitted parameters. These results show that, in regions of the atmosphere near amine sources, both amines and sulphur dioxide should be considered when assessing the impact of anthropogenic activities on particle formation. PMID:24097350

  5. Molecular understanding of sulphuric acid-amine particle nucleation in the atmosphere.

    PubMed

    Almeida, João; Schobesberger, Siegfried; Kürten, Andreas; Ortega, Ismael K; Kupiainen-Määttä, Oona; Praplan, Arnaud P; Adamov, Alexey; Amorim, Antonio; Bianchi, Federico; Breitenlechner, Martin; David, André; Dommen, Josef; Donahue, Neil M; Downard, Andrew; Dunne, Eimear; Duplissy, Jonathan; Ehrhart, Sebastian; Flagan, Richard C; Franchin, Alessandro; Guida, Roberto; Hakala, Jani; Hansel, Armin; Heinritzi, Martin; Henschel, Henning; Jokinen, Tuija; Junninen, Heikki; Kajos, Maija; Kangasluoma, Juha; Keskinen, Helmi; Kupc, Agnieszka; Kurtén, Theo; Kvashin, Alexander N; Laaksonen, Ari; Lehtipalo, Katrianne; Leiminger, Markus; Leppä, Johannes; Loukonen, Ville; Makhmutov, Vladimir; Mathot, Serge; McGrath, Matthew J; Nieminen, Tuomo; Olenius, Tinja; Onnela, Antti; Petäjä, Tuukka; Riccobono, Francesco; Riipinen, Ilona; Rissanen, Matti; Rondo, Linda; Ruuskanen, Taina; Santos, Filipe D; Sarnela, Nina; Schallhart, Simon; Schnitzhofer, Ralf; Seinfeld, John H; Simon, Mario; Sipilä, Mikko; Stozhkov, Yuri; Stratmann, Frank; Tomé, Antonio; Tröstl, Jasmin; Tsagkogeorgas, Georgios; Vaattovaara, Petri; Viisanen, Yrjo; Virtanen, Annele; Vrtala, Aron; Wagner, Paul E; Weingartner, Ernest; Wex, Heike; Williamson, Christina; Wimmer, Daniela; Ye, Penglin; Yli-Juuti, Taina; Carslaw, Kenneth S; Kulmala, Markku; Curtius, Joachim; Baltensperger, Urs; Worsnop, Douglas R; Vehkamäki, Hanna; Kirkby, Jasper

    2013-10-17

    Nucleation of aerosol particles from trace atmospheric vapours is thought to provide up to half of global cloud condensation nuclei. Aerosols can cause a net cooling of climate by scattering sunlight and by leading to smaller but more numerous cloud droplets, which makes clouds brighter and extends their lifetimes. Atmospheric aerosols derived from human activities are thought to have compensated for a large fraction of the warming caused by greenhouse gases. However, despite its importance for climate, atmospheric nucleation is poorly understood. Recently, it has been shown that sulphuric acid and ammonia cannot explain particle formation rates observed in the lower atmosphere. It is thought that amines may enhance nucleation, but until now there has been no direct evidence for amine ternary nucleation under atmospheric conditions. Here we use the CLOUD (Cosmics Leaving OUtdoor Droplets) chamber at CERN and find that dimethylamine above three parts per trillion by volume can enhance particle formation rates more than 1,000-fold compared with ammonia, sufficient to account for the particle formation rates observed in the atmosphere. Molecular analysis of the clusters reveals that the faster nucleation is explained by a base-stabilization mechanism involving acid-amine pairs, which strongly decrease evaporation. The ion-induced contribution is generally small, reflecting the high stability of sulphuric acid-dimethylamine clusters and indicating that galactic cosmic rays exert only a small influence on their formation, except at low overall formation rates. Our experimental measurements are well reproduced by a dynamical model based on quantum chemical calculations of binding energies of molecular clusters, without any fitted parameters. These results show that, in regions of the atmosphere near amine sources, both amines and sulphur dioxide should be considered when assessing the impact of anthropogenic activities on particle formation.

  6. Analysis of torsional spectra of molecules with two internal C/3v/ rotors. III - Far-infrared and gas phase Raman spectra of dimethylamine-d0, -d3, and -d6

    NASA Technical Reports Server (NTRS)

    Durig, J. R.; Griffin, M. G.; Groner, P.

    1977-01-01

    The Raman spectra of gaseous dimethylamine-d0, -d3, and -d6 have been recorded between 0 and 4000/cm. The far-infrared spectra have been recorded between 300 and 100/cm. Considerable torsional data are reported and used to characterize the torsional potential function based on a semi-rigid model. The average effective V3 for the dimethylamines was found to be 1052 plus or minus 12/cm. The cos-cos coupling term was approximately 15% of the effective V3, whereas the sine-sine coupling term was of an order of magnitude smaller for (CH3)2NH and (CD3)2NH. However, for the mixed isotope the sine-sine term was found to be negligible and the cos-cos about one-half the value obtained for the other two isotopes.

  7. Observation of new particle formation and measurement of sulfuric acid, ammonia, amines and highly oxidized organic molecules at a rural site in central Germany

    NASA Astrophysics Data System (ADS)

    Kürten, Andreas; Bergen, Anton; Heinritzi, Martin; Leiminger, Markus; Lorenz, Verena; Piel, Felix; Simon, Mario; Sitals, Robert; Wagner, Andrea C.; Curtius, Joachim

    2016-10-01

    The exact mechanisms for new particle formation (NPF) under different boundary layer conditions are not known yet. One important question is whether amines and sulfuric acid lead to efficient NPF in the atmosphere. Furthermore, it is not clear to what extent highly oxidized organic molecules (HOMs) are involved in NPF. We conducted field measurements at a rural site in central Germany in the proximity of three larger dairy farms to investigate whether there is a connection between NPF and the presence of amines and/or ammonia due to the local emissions from the farms. Comprehensive measurements using a nitrate chemical ionization-atmospheric pressure interface time-of-flight (CI-APi-TOF) mass spectrometer, a proton-transfer-reaction mass spectrometer (PTR-MS), particle counters and differential mobility analyzers (DMAs), as well as measurements of trace gases and meteorological parameters, were performed. We demonstrate here that the nitrate CI-APi-TOF is suitable for sensitive measurements of sulfuric acid, amines, a nitrosamine, ammonia, iodic acid and HOMs. NPF was found to correlate with sulfuric acid, while an anti-correlation with RH, amines and ammonia is observed. The anti-correlation between NPF and amines could be due to the efficient uptake of these compounds by nucleating clusters and small particles. Much higher HOM dimer (C19/C20 compounds) concentrations during the night than during the day indicate that these HOMs do not efficiently self-nucleate as no nighttime NPF is observed. Observed iodic acid probably originates from an iodine-containing reservoir substance, but the iodine signals are very likely too low to have a significant effect on NPF.

  8. Technical note: Detection of dimethylamine in the low pptv range using nitrate Chemical Ionization-Atmospheric Pressure interface-Time Of Flight (CI-APi-TOF) mass spectrometry

    NASA Astrophysics Data System (ADS)

    Simon, M.; Heinritzi, M.; Herzog, S.; Leiminger, M.; Bianchi, F.; Praplan, A.; Dommen, J.; Curtius, J.; Kürten, A.

    2015-12-01

    Amines are potentially important for atmospheric new particle formation and therefore the demand for highly sensitive gas phase amine measurements has emerged in the last several years. Nitrate Chemical Ionization Mass Spectrometry (CIMS) is routinely used for the measurement of gas phase-sulfuric acid in the sub-pptv range. Furthermore, Extremely Low Volatile Organic Compounds (ELVOCs) can be detected with a nitrate CIMS. In this study we demonstrate that a nitrate CIMS can also be used for the sensitive measurement of dimethylamine ((CH3)2NH, DMA) using the NO3-(HNO3)1-2(DMA) cluster ion signals. This observation was made at the CLOUD aerosol chamber, which was also used for calibration measurements. Good linearity between 0 and ~120 pptv of DMA as well as a sub-pptv detection limit of 0.7 pptv for a 10 min integration time are demonstrated at 278 K and 38 % RH.

  9. Enhancement in the production of nucleating clusters due to dimethylamine and large uncertainties in the thermochemistry of amine-enhanced nucleation

    NASA Astrophysics Data System (ADS)

    Nadykto, Alexey B.; Herb, Jason; Yu, Fangqun; Xu, Yisheng

    2014-08-01

    In the present Letter, the enhancing effect of dimethylamine (DMA) on the production of stable H2SO4-H2O clusters have been studied using the Density Functional Theory (DFT). It has been pointed out that the DMA concentrations of 1-10 ppt are needed in order to achieve a considerable enhancement in production of sulfuric acid-water clusters under typical atmospheric conditions and that the ambient RH plays a significant role at the early stages of the gas-to cluster conversion in the ternary DMA-H2SO4-H2O vapour mixtures. Large uncertainties in the thermochemistry of amine-enhanced nucleation have been pointed out and discussed.

  10. Renal Ammonia Metabolism and Transport

    PubMed Central

    Weiner, I. David; Verlander, Jill W.

    2015-01-01

    Renal ammonia metabolism and transport mediates a central role in acid-base homeostasis. In contrast to most renal solutes, the majority of renal ammonia excretion derives from intrarenal production, not from glomerular filtration. Renal ammoniagenesis predominantly results from glutamine metabolism, which produces 2 NH4+ and 2 HCO3− for each glutamine metabolized. The proximal tubule is the primary site for ammoniagenesis, but there is evidence for ammoniagenesis by most renal epithelial cells. Ammonia produced in the kidney is either excreted into the urine or returned to the systemic circulation through the renal veins. Ammonia excreted in the urine promotes acid excretion; ammonia returned to the systemic circulation is metabolized in the liver in a HCO3−-consuming process, resulting in no net benefit to acid-base homeostasis. Highly regulated ammonia transport by renal epithelial cells determines the proportion of ammonia excreted in the urine versus returned to the systemic circulation. The traditional paradigm of ammonia transport involving passive NH3 diffusion, protonation in the lumen and NH4+ trapping due to an inability to cross plasma membranes is being replaced by the recognition of limited plasma membrane NH3 permeability in combination with the presence of specific NH3-transporting and NH4+-transporting proteins in specific renal epithelial cells. Ammonia production and transport are regulated by a variety of factors, including extracellular pH and K+, and by several hormones, such as mineralocorticoids, glucocorticoids and angiotensin II. This coordinated process of regulated ammonia production and transport is critical for the effective maintenance of acid-base homeostasis. PMID:23720285

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

    NASA Astrophysics Data System (ADS)

    Hansen, K.; Sørensen, L. L.; Hornsby, K. E.; Boegh, E.; Pryor, S. C.

    2013-12-01

    Quantifying the atmosphere-biosphere exchange of reactive nitrogen gasses (including ammonia (NH3) and nitric acid (HNO3)) is crucial to assessing the impact of anthropogenic activities on natural and semi-natural ecosystems. However, measuring the deposition of reactive nitrogen is challenging due to bi-directionality of the flux, and the dynamics of the chemical gas/aerosol equilibrium of NH3 and HNO3 (or other atmospheric acids) with aerosol-phase ammonium (NH4+) and nitrate (NO3-). NH3 and HNO3 are both very reactive and typically exhibit higher deposition velocities than aerosol NH4+. Therefore, the phase partitioning between gas and aerosol phases can have a significant effect on local budgets and atmospheric transport distances (Nemitz et al., Atmos. Chem. Phys., 2004). In this study, fluxes of NH3, HNO3 and carbon dioxide (CO2) along with size-resolved N-aerosol concentrations are measured above the deciduous forest, Morgan Monroe State Forest (MMSF) in south-central Indiana (39°53'N, 86°25'W) during a field campaign. Two relaxed eddy accumulation (REA) systems are used to measure fluxes and concentrations of NH3 and HNO3 at 44 m. The NH3 REA system operates based on wet effluent diffusion denuders with detection by florescence and half-hourly flux measurements are calculated. HNO3 REA system is based on gas capture on sodium chloride (NaCl) coated denuders with subsequent analysis by ion-chromatography, and the resulting fluxes have a resolution of 3-4 hours. CO2 fluxes are measured by eddy covariance using a closed-path Licor LI-7500, while two MSP MOUDI-110 impactors are used to measure the 24-hourly average inorganic and 48 hourly averaged organic ion concentrations in 11 size bins, respectively, just above the canopy level (28 m). The results of this field campaign are used to quantify the fluxes of NH3, HNO3, CO2 to/from the forest during the transition towards senescence, and to investigate process-level controls (e.g. the role of phase

  12. Mitigating ammonia inhibition of thermophilic anaerobic treatment of digested piggery wastewater: use of pH reduction, zeolite, biomass and humic acid.

    PubMed

    Ho, L; Ho, G

    2012-09-15

    High free ammonia released during anaerobic digestion of livestock wastes is widely known to inhibit methanogenic microorganisms and result in low methane production. This was encountered during our earlier thermophilic semi-continuously fed continuously-stirred tank reactor (CSTR) treatment of piggery wastewater. This study explored chemical and biological means to mitigate ammonia inhibition on thermophilic anaerobic treatment of piggery wastewater with the aim to increase organic volatile carbon reduction and methane production. A series of thermophilic anaerobic batch experiments were conducted on the digested piggery effluent to investigate the effects of pH reduction (pH 8.3 to 7.5, 7.0 and 6.5) and additions of biomass (10% v/v and 19% v/v anaerobic digested piggery biomass and aerobic-anaerobic digested municipal biomass), natural zeolite (10, 15 and 20 g/L) and humic acid (1, 5 and 10 g/L) on methane production at 55 °C for 9-11 days. Reduction of the wastewater pH from its initial pH of 8.3 to 6.5 produced the greatest stimulation of methane production (3.4 fold) coupled with reductions in free ammonia (38 fold) and total volatile fatty acids (58% TVFA), particularly acetate and propionate. Addition of 10-20 g/L zeolite to piggery wastewater with and without pH reduction to 6.5 further enhanced total VFA reduction and methane production over their respective controls, with 20 g/L zeolite producing the highest enhancement effect despite the ammonia-nitrogen concentrations of the treated wastewaters remaining high. Without pH reduction, zeolite concentration up to 20 g/L was required to achieve comparable methane enhancement as the pH-reduced wastewater at pH 6.5. Although biomass (10% v/v piggery and municipal wastes) and low humic acid (1 and 5 g/L) additions enhanced total VFA reduction and methane production, they elevated the residual effluent total COD concentrations over the control wastewaters (pH-unadjusted and pH-reduced) unlike zeolite

  13. Molecular Characterization of a Recombinant Zea mays Phenylalanine Ammonia-Lyase (ZmPAL2) and Its Application in trans-Cinnamic Acid Production from L-Phenylalanine.

    PubMed

    Zang, Ying; Jiang, Ting; Cong, Ying; Zheng, Zhaojuan; Ouyang, Jia

    2015-06-01

    Phenylalanine ammonia-lyase (PAL) is one of the most extensively studied enzymes with its crucial role in secondary phenylpropanoid metabolism of plants. Recently, its demand has been increased for aromatic chemical production, but its applications in trans-cinnamic acid production were not much explored. In the present study, a putative PAL gene from Zea mays designated as ZmPAL2 was expressed and characterized in Escherichia coli BL21 (DE3). The recombinant ZmPAL2 exhibited a high PAL activity (7.14 U/mg) and a weak tyrosine ammonia-lyase activity. The optimal temperature of ZmPAL2 was 55 °C, and the thermal stability results showed that about 50 % of enzyme activity remained after a treatment at 60 °C for 6 h. The recombinant ZmPAL2 is a good candidate for the production of trans-cinnamic acid. The vitro conversion indicated that the recombinant ZmPAL2 could effectively catalyze the L-phenylalanine to trans-cinnamic acid, and the trans-cinnamic acid concentration can reach up to 5 g/l.

  14. [Change in the content of salicylic acid and activities of phenylalanine ammonia-lyase and catalase in wheat seedling roots under the influence of Azospirilium lectins].

    PubMed

    Alen'kina, S A; Trutneva, K A; Nikitina, V E

    2013-01-01

    The time course of changes in the endogenous content of salicylic acid, the ratio between the acid's free and bound forms, and changes in the activities of phenylalanine ammonia-lyase and catalase in wheat seedling roots under the effect of lectins of two strains of the associative nitrogen-fixing bacterium Azospirillum (A. brasilense Sp7 and its mutant defective in lectin activity, A. brasilense Sp7.2.3) is investigated. Differences in plant response to the action of the lectins from these two strains are established. On the basis of the obtained data, a model is proposed for lectin-assisted induction of resistance, according to which the lectin effect on the roots of seedlings results in the accumulation of free salicylic acid, which inhibits catalase activity, ultimately leading to accumulation of hydrogen peroxide and formation of induced resistance. PMID:25518563

  15. [Change in the content of salicylic acid and activities of phenylalanine ammonia-lyase and catalase in wheat seedling roots under the influence of Azospirilium lectins].

    PubMed

    Alen'kina, S A; Trutneva, K A; Nikitina, V E

    2013-01-01

    The time course of changes in the endogenous content of salicylic acid, the ratio between the acid's free and bound forms, and changes in the activities of phenylalanine ammonia-lyase and catalase in wheat seedling roots under the effect of lectins of two strains of the associative nitrogen-fixing bacterium Azospirillum (A. brasilense Sp7 and its mutant defective in lectin activity, A. brasilense Sp7.2.3) is investigated. Differences in plant response to the action of the lectins from these two strains are established. On the basis of the obtained data, a model is proposed for lectin-assisted induction of resistance, according to which the lectin effect on the roots of seedlings results in the accumulation of free salicylic acid, which inhibits catalase activity, ultimately leading to accumulation of hydrogen peroxide and formation of induced resistance.

  16. Ammonia Test

    MedlinePlus

    ... be ordered, along with other tests such as glucose , electrolytes , and kidney and liver function tests , to help diagnose the cause of ... Pages tab.) An increased ammonia level and decreased glucose ... may indicate that severe liver or kidney damage has impacted the body's ability ...

  17. Evidence of novel plant-species specific ammonia oxidizing bacterial clades in acidic South African fynbos soils.

    PubMed

    Ramond, Jean-Baptiste; Lako, Joseph D W; Stafford, William H L; Tuffin, Marla I; Cowan, Don A

    2015-08-01

    Ammonia-oxidizing bacteria (AOB) are essential in the biogeochemical cycling of nitrogen as they catalyze the rate-limiting oxidation of ammonia into nitrite. Since their first isolation in the late 19th century, chemolithoautotrophic AOBs have been identified in a wide range of natural (e.g., soils, sediments, estuarine, and freshwaters) and man created or impacted habitats (e.g., wastewater treatment plants and agricultural soils). However, little is known on the plant-species association of AOBs, particularly in the nutrient-starved fynbos terrestrial biome. In this study, we evaluated the diversity of AOBs in the plant canopy of three South African fynbos-specific plant species, namely Leucadendron xanthoconus, Leucospermum truncatulum and Leucadendron microcephalum, through the construction of amoA-gene clone libraries. Our results clearly demonstrate that plant-species specific and monophyletic AOB clades are present in fynbos canopy soils.

  18. Multiple functions of the crustacean gill: osmotic/ionic regulation, acid-base balance, ammonia excretion, and bioaccumulation of toxic metals

    PubMed Central

    Henry, Raymond P.; Lucu, Čedomil; Onken, Horst; Weihrauch, Dirk

    2012-01-01

    The crustacean gill is a multi-functional organ, and it is the site of a number of physiological processes, including ion transport, which is the basis for hemolymph osmoregulation; acid-base balance; and ammonia excretion. The gill is also the site by which many toxic metals are taken up by aquatic crustaceans, and thus it plays an important role in the toxicology of these species. This review provides a comprehensive overview of the ecology, physiology, biochemistry, and molecular biology of the mechanisms of osmotic and ionic regulation performed by the gill. The current concepts of the mechanisms of ion transport, the structural, biochemical, and molecular bases of systemic physiology, and the history of their development are discussed. The relationship between branchial ion transport and hemolymph acid-base regulation is also treated. In addition, the mechanisms of ammonia transport and excretion across the gill are discussed. And finally, the toxicology of heavy metal accumulation via the gill is reviewed in detail. PMID:23162474

  19. Interactions of methylamine and ammonia with atmospheric nucleation precursor H2SO4 and common organic acids: Thermodynamics and atmospheric implications

    NASA Astrophysics Data System (ADS)

    Xu, Y.; Nadykto, A. B.; Jiang, L.; Bai, Z.

    2016-06-01

    Interactions of the two common atmospheric bases, ammonia (NH3) and methylamine MA (CH3NH2), which are considered to be important stabilizers of binary clusters in the Earth's atmosphere, with H2SO4, the key atmospheric precursor, and 14 common atmospheric organic acids (COA) (formic (CH2O2), acetic (C2H4O2), oxalic (C2H2O4), malonic (C3H4O4), succinic (C4H6O4), glutaric acid (C5H8O4), adipic (C6H10O4), benzoic (C6H5COOH), phenylacetic (C6H5CH2COOH), pyruvic (C3H4O3), maleic acid (C4H4O4), malic (C4H6O5), tartaric (C4H6O6) and pinonic acid (C10H16O3)) have been studied using the composite high-accuracy G3MP2 method. The thermodynamic stability of mixed (COA) (H2SO4), (COA)(B1) and (COA)(B2) dimers and (COA) (H2SO4) (B1) and (COA) (H2SO4) (B1) trimers, where B1 and B2 represent methylamine (CH3NH2) and ammonia (NH3), respectively, have been investigated and their impacts on the thermodynamic stability of clusters containing H2SO4 have been analyzed. It has been shown that in many cases the interactions of H2SO4 with COA, ammonia and methylamine lead to the formation of heteromolecular dimers and trimers, which are certainly more stable than (H2SO4)2 and (H2SO4)3. It has also been found that free energies of (COA) (H2SO4)+ CH3NH2⇔(COA) (H2SO4)(CH3NH2) reactions exceed 10-15 kcal mol-1. This is a clear indication that mixed trimers composed of COA, H2SO4 and methylamine are very stable and can thus serve as possible nucleation sites. The present study leads us to conclude that the interactions of COA coexisting with H2SO4 and common atmospheric bases in the Earth's atmosphere may be an important factor affecting the stability of nucleating sulfuric acid clusters and that the impacts of COA on atmospheric nucleation should be studied in further details.

  20. 4-Vinylphenol biosynthesis from cellulose as the sole carbon source using phenolic acid decarboxylase- and tyrosine ammonia lyase-expressing Streptomyces lividans.

    PubMed

    Noda, Shuhei; Kawai, Yoshifumi; Tanaka, Tsutomu; Kondo, Akihiko

    2015-03-01

    Streptomyces lividans was adopted as a host strain for 4-vinylphenol (4VPh) production directly from cellulose. In order to obtain novel phenolic acid decarboxylase (PAD) expressed in S. lividans, PADs distributed among Streptomyces species were screened. Three novel PADs, derived from Streptomycessviceus, Streptomyceshygroscopicus, and Streptomycescattleya, were successfully obtained and expressed in S. lividans. S. sviceus PAD (SsPAD) could convert p-hydroxycinnamic acid (pHCA) to 4VPh more efficiently than the others both in vitro and in vivo. For 4VPh production directly from cellulose, l-tyrosine ammonia lyase derived from Rhodobacter sphaeroides and SsPAD were introduced into endoglucanase-secreting S. lividans, and the 4VPh biosynthetic pathway was constructed therein. The created transformants successfully produced 4VPh directly from cellulose.

  1. Stress enhances the gene expression and enzyme activity of phenylalanine ammonia-lyase and the endogenous content of salicylic acid to induce flowering in pharbitis.

    PubMed

    Wada, Kaede C; Mizuuchi, Kaori; Koshio, Aya; Kaneko, Kentaro; Mitsui, Toshiaki; Takeno, Kiyotoshi

    2014-07-01

    The involvement of salicylic acid (SA) in the regulation of stress-induced flowering in the short-day plant pharbitis (also called Japanese morning glory) Ipomoea nil (formerly Pharbitis nil) was studied. Pharbitis cv. Violet was induced to flower when grown in 1/100-strength mineral nutrient solution under non-inductive long-day conditions. All fully expanded true leaves were removed from seedlings, leaving only the cotyledons, and flowering was induced under poor-nutrition stress conditions. This indicates that cotyledons can play a role in the regulation of poor-nutrition stress-induced flowering. The expression of the pharbitis homolog of PHENYLALANINE AMMONIA-LYASE, the enzyme activity of phenylalanine ammonia-lyase (PAL; E.C. 4.3.1.5) and the content of SA in the cotyledons were all up-regulated by the stress treatment. The Violet was also induced to flower by low-temperature stress, DNA demethylation and short-day treatment. Low-temperature stress enhanced PAL activity, whereas non-stress factors such as DNA demethylation and short-day treatment decreased the activity. The PAL enzyme activity was also examined in another cultivar, Tendan, obtaining similar results to Violet. The exogenously applied SA did not induce flowering under non-stress conditions but did promote flowering under weak stress conditions in both cultivars. These results suggest that stress-induced flowering in pharbitis is induced, at least partly, by SA, and the synthesis of SA is promoted by PAL.

  2. Effects of ruminal ammonia and butyrate concentrations on reticuloruminal epithelial blood flow and volatile fatty acid absorption kinetics under washed reticulorumen conditions in lactating dairy cows.

    PubMed

    Storm, A C; Hanigan, M D; Kristensen, N B

    2011-08-01

    The effect of reticuloruminal epithelial blood flow on the absorption of propionate as a volatile fatty acid (VFA) marker in 8 lactating Holstein cows was studied under washed rumen conditions. The cows were surgically prepared with ruminal cannulas and permanent catheters in an artery and mesenteric, right ruminal, and hepatic portal veins. The experiment was designed with 2 groups of cows: 4 cows adapted to high crude protein (CP) and 4 to low CP. All cows were subjected to 3 buffers: butyric, ammonia, and control in a randomized replicated 3 × 3 incomplete Latin square design. The buffers (30 kg) were maintained in a temporarily emptied and washed rumen for 40 min. The initial concentration of VFA was 84.2 mmol/L. Butyrate was increased from 4 to 36 mmol/L in butyric buffer by replacement of acetate, and ammonia (NH(3)) was increased from 2.5 to 22.5 mmol/L in ammonia buffer by replacement of NaCl. Increasing amounts of deuterium oxide (D(2)O) were added to the buffers as the order of buffer sequence increased (6, 12, and 18 g of D(2)O). Ruminal clearance of D(2)O was used to estimate epithelial blood flow. To increase accuracy of the epithelial blood flow estimates, data of ruminal liquid marker (Cr-EDTA), and initial and final buffer volumes were fitted to a dynamic simulation model. The model was used to estimate ruminal liquid passages, residual liquid, and water influx (saliva and epithelia water) for each combination of cow and buffer (n=24). Epithelial blood flow increased 49±11% for butyric buffer compared with control. The ruminal disappearance of propionate (marker VFA) was affected by buffer and followed the same pattern as for epithelial blood flow. The correlation between ruminal disappearance of propionate and epithelial blood flow (r=0.56) indicates that the removal of propionate can be limited by epithelial blood flow. The ruminal disappearance of propionate increased 30±12% for the butyric compared with ammonia buffer and 12.5±8% when

  3. Effects of ruminal ammonia and butyrate concentrations on reticuloruminal epithelial blood flow and volatile fatty acid absorption kinetics under washed reticulorumen conditions in lactating dairy cows.

    PubMed

    Storm, A C; Hanigan, M D; Kristensen, N B

    2011-08-01

    The effect of reticuloruminal epithelial blood flow on the absorption of propionate as a volatile fatty acid (VFA) marker in 8 lactating Holstein cows was studied under washed rumen conditions. The cows were surgically prepared with ruminal cannulas and permanent catheters in an artery and mesenteric, right ruminal, and hepatic portal veins. The experiment was designed with 2 groups of cows: 4 cows adapted to high crude protein (CP) and 4 to low CP. All cows were subjected to 3 buffers: butyric, ammonia, and control in a randomized replicated 3 × 3 incomplete Latin square design. The buffers (30 kg) were maintained in a temporarily emptied and washed rumen for 40 min. The initial concentration of VFA was 84.2 mmol/L. Butyrate was increased from 4 to 36 mmol/L in butyric buffer by replacement of acetate, and ammonia (NH(3)) was increased from 2.5 to 22.5 mmol/L in ammonia buffer by replacement of NaCl. Increasing amounts of deuterium oxide (D(2)O) were added to the buffers as the order of buffer sequence increased (6, 12, and 18 g of D(2)O). Ruminal clearance of D(2)O was used to estimate epithelial blood flow. To increase accuracy of the epithelial blood flow estimates, data of ruminal liquid marker (Cr-EDTA), and initial and final buffer volumes were fitted to a dynamic simulation model. The model was used to estimate ruminal liquid passages, residual liquid, and water influx (saliva and epithelia water) for each combination of cow and buffer (n=24). Epithelial blood flow increased 49±11% for butyric buffer compared with control. The ruminal disappearance of propionate (marker VFA) was affected by buffer and followed the same pattern as for epithelial blood flow. The correlation between ruminal disappearance of propionate and epithelial blood flow (r=0.56) indicates that the removal of propionate can be limited by epithelial blood flow. The ruminal disappearance of propionate increased 30±12% for the butyric compared with ammonia buffer and 12.5±8% when

  4. Oceanic emissions of ammonia

    NASA Astrophysics Data System (ADS)

    Paulot, F.; Jacob, D. J.; Johnson, M.; Bell, T. G.; Stock, C. A.; Doney, S. C.

    2013-12-01

    Half of natural ammonia (NH3) emissions is thought to originate from the oceans. Such large emissions have implications for the global budget of N and the acidity of marine aerosols. We develop two new inventories of oceanic NH3 emissions based on simulated monthly NH3 seawater concentrations from the GFDL-COBALT and the CESM-BEC ocean models. These new inventories explicitly account for the effect of temperature on the water-atmosphere exchange of NH3. We evaluate these inventory using cruise observations of gas-phase ammonia (AMT cruises) and ammonium (NOAA cruises) as well as seawater measurement of NHx. Implications of atmospheric NHx observations for the exchange of N between ocean and land and ocean N/P limitations are discussed.

  5. Thin film transistors based on poly(3-hexylthiophene)/[6,6]-phenyl C61 butyric acid methyl ester hetero-junction for ammonia detection

    NASA Astrophysics Data System (ADS)

    Chen, Yuyan; Xie, Guangzhong; Xie, Tao; Liu, Yanni; Du, Hongfei; Su, Yuanjie; Jiang, Yadong

    2015-10-01

    Composite film and bilayer film based on poly(3-hexylthiophene) (P3HT)/[6,6]-phenyl C61 butyric acid methyl ester(PC61BM) were firstly utilized as active layers of OTFT sensor. By comparing with electrical and sensing properties of these different devices for ammonia (NH3) at room temperature, the device based on PC61BM/P3HT composite film exhibited the optimum characteristics. The recovery value of PC61BM/P3HT composite film reached 93.9% of its initial value at 20 ppm NH3 within 9 min, which was improved by 75.5% in comparison with the one based on pristine P3HT film. In addition, the sensing mechanisms of all sensors were studied as well.

  6. Combining pH and electrical conductivity measurements to improve titrimetric methods to determine ammonia nitrogen, volatile fatty acids and inorganic carbon concentrations.

    PubMed

    Charnier, C; Latrille, E; Lardon, L; Miroux, J; Steyer, J P

    2016-05-15

    Volatile fatty acids (VFA), inorganic carbon (IC) and total ammonia nitrogen (TAN) are key variables in the current context of anaerobic digestion (AD). Accurate measurements like gas chromatography and infrared spectrometry have been developed to follow the concentration of these compounds but none of these methods are affordable for small AD units. Only titration methods answer the need for small plant monitoring. The existing methods accuracy was assessed in this study and reveals a lack of accuracy and robustness to control AD plants. To solve these issues, a new titrimetric device to estimate the VFA, IC and TAN concentrations with an improved accuracy was developed. This device named SNAC (System of titration for total ammonia Nitrogen, volatile fatty Acids and inorganic Carbon) has been developed combining the measurement of electrical conductivity and pH. SNAC were tested on 24 different plant samples in a range of 0-0.16 mol.L(-1) TAN, 0.01-0.21 mol.L(-1) IC and 0-0.04 mol.L(-1) VFA. The standard error was about 0.012 mol.L(-1) TAN, 0.015 mol.L(-1) IC and 0.003 mol.L(-1) VFA. The coefficient of determination R(2) between the estimated and reference data was 0.95, 0.94 and 0.95 for TAN, IC and VFA respectively. Using the same data, current methods based on key pH points lead to standard error more than 14.5 times higher on VFA and more than 1.2 times higher on IC. These results show that SNAC is an accurate tool to improve the management of AD plant.

  7. Low-temperature synthesis of allyl dimethylamine by selective heating under microwave irradiation used for water treatment

    NASA Astrophysics Data System (ADS)

    Tian, Binghui; Luan, Zhaokun; Li, Mingming

    2005-08-01

    Low-temperature synthesis of allyl dimethylamine (ADA) by selective heating under microwave irradiation (MI) used for water treatment is investigated. The effect of MI, ultrasound irradiation (UI) and conventional heating on yield of ADA, reaction time and the flocculation efficiency of polydiallyl dimethylammunion chloride (PDADMAC) prepared form ADA were studied. The results show that by selective heating at low temperature, MI not only increases yield of ADA and reduces reaction time, but also greatly enhances the flocculation efficiency of PDADMAC.

  8. Sol-gel process for preparing YBa{sub 2}Cu{sub 4}O{sub 8} precursors from Y, Ba, and Cu acidic acetates/ammonia/ascorbic acid systems

    SciTech Connect

    Deptula, A.; Lada, W.; Olczak, T.; Goretta, K.C.; Di Bartolomeo, A.; Casadio, S.

    1995-08-01

    Sols were prepared by addition of ammonia to acidic acetate solutions of Y{sup 3+}, Ba{sup 2+}, and Cu{sup 2+}. Ascorbic acid was added to a part of the sol. The resultant sols were gelled to a shard, a film, or microspheres by evaporation at 60 C or by extraction of water from drops of emulsion suspended in 2-ethylhexanol-1. Addition of ethanol to the sols facilitated the formation of gel films, fabricated by a dipping technique, on glass or silver substrates. At 100 C, gels that were formed in the presence of ascorbic acid were perfectly amorphous, in contrast to the crystalline acetate gels. Conversion of the amorphous ascorbate gels to final products was easier than for the acetate gels. The quality of coatings prepared from ascorbate gels was superior to that of acetate gel coatings.

  9. Pretreatment of Dried Distiller Grains with Solubles by Soaking in Aqueous Ammonia and Subsequent Enzymatic/Dilute Acid Hydrolysis to Produce Fermentable Sugars.

    PubMed

    Nghiem, Nhuan P; Montanti, Justin; Kim, Tae Hyun

    2016-05-01

    Dried distillers grains with solubles (DDGS), a co-product of corn ethanol production in the dry-grind process, was pretreated by soaking in aqueous ammonia (SAA) using a 15 % w/w NH4OH solution at a solid/liquid ratio of 1:10. The effect of pretreatment on subsequent enzymatic hydrolysis was studied at two temperatures (40 and 60 °C) and four reaction times (6, 12, 24, and 48 h). Highest glucose yield of 91 % theoretical was obtained for the DDGS pretreated at 60 °C and 24 h. The solubilized hemicellulose in the liquid fraction was further hydrolyzed with dilute H2SO4 to generate fermentable monomeric sugars. The conditions of acid hydrolysis included 1 and 4 wt% acid, 60 and 120 °C, and 0.5 and 1 h. Highest yields of xylose and arabinose were obtained at 4 wt% acid, 120 °C, and 1 h. The fermentability of the hydrolysate obtained by enzymatic hydrolysis of the SAA-pretreated DDGS was demonstrated in ethanol fermentation by Saccharomyces cerevisiae. The fermentability of the hydrolysate obtained by consecutive enzymatic and dilute acid hydrolysis was demonstrated using a succinic acid-producing microorganism, strain Escherichia coli AFP184. Under the fermentation conditions, complete utilization of glucose and arabinose was observed, whereas only 47 % of xylose was used. The succinic acid yield was 0.60 g/g total sugar consumed. PMID:26797927

  10. Amine permeation sources characterized with acid neutralization and sensitivities of an amine mass spectrometer

    NASA Astrophysics Data System (ADS)

    Freshour, N. A.; Carlson, K. K.; Melka, Y. A.; Hinz, S.; Panta, B.; Hanson, D. R.

    2014-10-01

    An acid titration method for quantifying amine permeation rates was used to calibrate an Ambient pressure Proton transfer Mass Spectrometer (AmPMS) that monitors ambient amine compounds. The method involves capturing amines entrained in a N2 flow by bubbling it through an acidified solution (~10-5 M HCl), and the amines are quantified via changes in solution pH with time. Home-made permeation tubes had permeation rates (typically tens of pmol s-1) that depended on the type of amine and tubing and on temperature. Calibrations of AmPMS yielded sensitivities for ammonia, methylamine, dimethylamine, and trimethylamine that are close to the sensitivity assuming a gas-kinetic, ion-molecule rate coefficient. The permeation tubes were also designed to deliver a reproducible amount of amine to a flow reactor where nucleation with sulfuric acid was studied. The high proton affinity compound dimethyl sulfoxide (DMSO), linked to oceanic environments, was also studied and AmPMS is highly sensitive to it. AmPMS was deployed recently in two field campaigns and, using these sensitivities, mixing ratios for ammonia and the alkyl amines are derived from the signals. Correlations between these species and with particle formation events are discussed.

  11. Urinary excretion of 3-methyladenine after consumption of fish containing high levels of dimethylamine.

    PubMed

    Fay, L B; Leaf, C D; Gremaud, E; Aeschlimann, J M; Steen, C; Shuker, D E; Turesky, R J

    1997-05-01

    The urinary excretion of the DNA alkylation product, 3-methyladenine (3-MeAde), was measured in human volunteers who were on controlled diets and consumed fresh fish, or frozen-stored fish that contained 50-fold higher levels of dimethylamine (DMA), with or without ingested nitrate. DMA potentially could react with nitrosating agents in the diet or within the body, and produce the potent carcinogen N-nitrosodimethylamine (NDMA), which can then react with DNA to form several adducts including 3-MeAde. Our findings show that there was no increase in urinary levels of 3-MeAde after consumption of fish preserved by frozen storage relative to levels after consumption of fresh fish. Furthermore, consumption of 225 mg sodium nitrate (equal to the nitrate content in a large glass of beet juice) at 1 h prior to consumption of the frozen-stored fish did not increase urinary 3-MeAde levels as would be expected if nitrate enhanced endogenous nitrosation of DMA. In contrast, urinary excretion of 3-MeAde from a volunteer who was a moderate cigarette smoker (11 cigarettes per day) was approximately 3- to 8-fold higher than dietary 3-MeAde intake. These findings indicate that consumption of high levels of DMA in fish does not result in detectable levels of NDMA formation and genetic damage as measured by the urinary biomarker 3-MeAde. PMID:9163693

  12. Effect of dietary protein restriction on renal ammonia metabolism.

    PubMed

    Lee, Hyun-Wook; Osis, Gunars; Handlogten, Mary E; Guo, Hui; Verlander, Jill W; Weiner, I David

    2015-06-15

    Dietary protein restriction has multiple benefits in kidney disease. Because protein intake is a major determinant of endogenous acid production, it is important that net acid excretion change in parallel during protein restriction. Ammonia is the primary component of net acid excretion, and inappropriate ammonia excretion can lead to negative nitrogen balance. Accordingly, we examined ammonia excretion in response to protein restriction and then we determined the molecular mechanism of the changes observed. Wild-type C57Bl/6 mice fed a 20% protein diet and then changed to 6% protein developed an 85% reduction in ammonia excretion within 2 days, which persisted during a 10-day study. The expression of multiple proteins involved in renal ammonia metabolism was altered, including the ammonia-generating enzymes phosphate-dependent glutaminase (PDG) and phosphoenolpyruvate carboxykinase (PEPCK) and the ammonia-metabolizing enzyme glutamine synthetase. Rhbg, an ammonia transporter, increased in expression in the inner stripe of outer medullary collecting duct intercalated cell (OMCDis-IC). However, collecting duct-specific Rhbg deletion did not alter the response to protein restriction. Rhcg deletion did not alter ammonia excretion in response to dietary protein restriction. These results indicate 1) dietary protein restriction decreases renal ammonia excretion through coordinated regulation of multiple components of ammonia metabolism; 2) increased Rhbg expression in the OMCDis-IC may indicate a biological role in addition to ammonia transport; and 3) Rhcg expression is not necessary to decrease ammonia excretion during dietary protein restriction. PMID:25925252

  13. Effect of dietary protein restriction on renal ammonia metabolism.

    PubMed

    Lee, Hyun-Wook; Osis, Gunars; Handlogten, Mary E; Guo, Hui; Verlander, Jill W; Weiner, I David

    2015-06-15

    Dietary protein restriction has multiple benefits in kidney disease. Because protein intake is a major determinant of endogenous acid production, it is important that net acid excretion change in parallel during protein restriction. Ammonia is the primary component of net acid excretion, and inappropriate ammonia excretion can lead to negative nitrogen balance. Accordingly, we examined ammonia excretion in response to protein restriction and then we determined the molecular mechanism of the changes observed. Wild-type C57Bl/6 mice fed a 20% protein diet and then changed to 6% protein developed an 85% reduction in ammonia excretion within 2 days, which persisted during a 10-day study. The expression of multiple proteins involved in renal ammonia metabolism was altered, including the ammonia-generating enzymes phosphate-dependent glutaminase (PDG) and phosphoenolpyruvate carboxykinase (PEPCK) and the ammonia-metabolizing enzyme glutamine synthetase. Rhbg, an ammonia transporter, increased in expression in the inner stripe of outer medullary collecting duct intercalated cell (OMCDis-IC). However, collecting duct-specific Rhbg deletion did not alter the response to protein restriction. Rhcg deletion did not alter ammonia excretion in response to dietary protein restriction. These results indicate 1) dietary protein restriction decreases renal ammonia excretion through coordinated regulation of multiple components of ammonia metabolism; 2) increased Rhbg expression in the OMCDis-IC may indicate a biological role in addition to ammonia transport; and 3) Rhcg expression is not necessary to decrease ammonia excretion during dietary protein restriction.

  14. Ammonia measurement with a pH electrode in the ammonia/urea-SCR process

    NASA Astrophysics Data System (ADS)

    Kröcher, Oliver; Elsener, Martin

    2007-03-01

    The selective catalytic reduction of nitrogen oxides with ammonia (ammonia SCR) and urea (urea SCR), respectively, is a widespread process to clean flue and diesel exhaust gases due to its simplicity and efficiency. The main challenge of the process is to minimize the ammonia emissions downstream of the SCR catalyst. We found that ammonia emissions of >10 ppm can reliably be detected with a simple pH electrode in the presence of CO2, SOx, NOx, and moderately weak organic acids. 10-20 ppm of ammonia in the exhaust gas are sufficient to neutralize the acids and to increase the pH value from 3 to 6. On this basis a continuous measuring method for ammonia was developed, which was used to control the dosage of urea in the SCR process. While keeping the ammonia emissions after the SCR catalyst at 5-30 ppm an average NOx removal efficiency (DeNOx) of >95% were achieved at a diesel test rig. The method can also be applied for exhaust gases with higher acid contents, if a basic pre-filter is added adsorbing the acidic exhaust components. Compared to water as absorption solution, more precise ammonia measurements are possible, if a 0.1 M NH4Cl absorption solution is applied, whose pH value is changing as a Nernst function of the ammonia concentration.

  15. The Ammonia Smoke Fountain: An Interesting Thermodynamic Adventure.

    ERIC Educational Resources Information Center

    Alexander, M. Dale

    1999-01-01

    Describes a new demonstration that uses an apparatus like the ammonia-fountain apparatus but with modifications designed to produce ammonium-chloride smoke. This demonstration is easy to perform, interesting to observe, and allows demonstration of the solubility of ammonia in water, the basic nature of ammonia, the acidic nature of hydrogen…

  16. Molecular cloning and promoter analysis of the specific salicylic acid biosynthetic pathway gene phenylalanine ammonia-lyase (AaPAL1) from Artemisia annua.

    PubMed

    Zhang, Ying; Fu, Xueqing; Hao, Xiaolong; Zhang, Lida; Wang, Luyao; Qian, Hongmei; Zhao, Jingya

    2016-07-01

    Phenylalanine ammonia-lyase (PAL) is the key enzyme in the biosynthetic pathway of salicylic acid (SA). In this study, a full-length cDNA of PAL gene (named as AaPAL1) was cloned from Artemisia annua. The gene contains an open reading frame of 2,151 bps encoding 716 amino acids. Comparative and bioinformatics analysis revealed that the polypeptide protein of AaPAL1 was highly homologous to PALs from other plant species. Southern blot analysis revealed that it belonged to a gene family with three members. Quantitative RT-PCR analysis of various tissues of A. annua showed that AaPAL1 transcript levels were highest in the young leaves. A 1160-bp promoter region was also isolated resulting in identification of distinct cis-regulatory elements including W-box, TGACG-motif, and TC-rich repeats. Quantitative RT-PCR indicated that AaPAL1 was upregulated by salinity, drought, wounding, and SA stresses, which were corroborated positively with the identified cis-elements within the promoter region. AaPAL1 was successfully expressed in Escherichia. coli and the enzyme activity of the purified AaPAL1 was approximately 287.2 U/mg. These results substantiated the involvement of AaPAL1 in the phenylalanine pathway. PMID:26040426

  17. Detection of dimethylamine in the low pptv range using nitrate chemical ionization atmospheric pressure interface time-of-flight (CI-APi-TOF) mass spectrometry

    NASA Astrophysics Data System (ADS)

    Simon, Mario; Heinritzi, Martin; Herzog, Stephan; Leiminger, Markus; Bianchi, Federico; Praplan, Arnaud; Dommen, Josef; Curtius, Joachim; Kürten, Andreas

    2016-05-01

    Amines are potentially important for atmospheric new particle formation, but their concentrations are usually low with typical mixing ratios in the pptv range or even smaller. Therefore, the demand for highly sensitive gas-phase amine measurements has emerged in the last several years. Nitrate chemical ionization mass spectrometry (CIMS) is routinely used for the measurement of gas-phase sulfuric acid in the sub-pptv range. Furthermore, extremely low volatile organic compounds (ELVOCs) can be detected with a nitrate CIMS. In this study we demonstrate that a nitrate CIMS can also be used for the sensitive measurement of dimethylamine (DMA, (CH3)2NH) using the NO3-•(HNO3)1 - 2• (DMA) cluster ion signal. Calibration measurements were made at the CLOUD chamber during two different measurement campaigns. Good linearity between 0 and ˜ 120 pptv of DMA as well as a sub-pptv detection limit of 0.7 pptv for a 10 min integration time are demonstrated at 278 K and 38 % RH.

  18. Impacts of epichlorohydrin-dimethylamine on coagulation performance and membrane fouling in coagulation/ultrafiltration combined process with different Al-based coagulants.

    PubMed

    Bu, Fan; Gao, Baoyu; Li, Ruihua; Sun, Shenglei; Yue, Qinyan

    2016-09-01

    Two kinds of aluminum-based coagulants and epichlorohydrin-dimethylamine (DAM-ECH) were used in the treatment of humic acid-kaolin simulated water by coagulation-ultrafiltration (C-UF) hybrid process. Coagulation performance, floc characteristics, including floc size, compact degree, and strength were investigated in this study. Ultrafiltration experiments were conducted by a dead-end batch unit to implement the resistance analyses to explore the membrane fouling mechanisms. Results showed that DAM-ECH aid significantly increased the UV254 and DOC removal efficiencies and contributed to the formation of larger and stronger flocs with a looser structure. Aluminum chloride (Al) gave rise to better coagulation performance with DAM-ECH compared with poly aluminum chloride (PACl). The consequences of ultrafiltration experiments showed that DAM-ECH aid could reduce the membrane fouling mainly by decreasing the cake layer resistance. The flux reductions for PACl, Al/DAM-ECH (dosing both Al and DAM-ECH) and PACl/DAM-ECH (dosing both PACl and DAM-ECH) were 62%, 56% and 44%, respectively. Results of this study would be beneficial for the application of PACl/DAM-ECH and Al/DAM-ECH composite coagulants in water treatment processes.

  19. Impacts of epichlorohydrin-dimethylamine on coagulation performance and membrane fouling in coagulation/ultrafiltration combined process with different Al-based coagulants.

    PubMed

    Bu, Fan; Gao, Baoyu; Li, Ruihua; Sun, Shenglei; Yue, Qinyan

    2016-09-01

    Two kinds of aluminum-based coagulants and epichlorohydrin-dimethylamine (DAM-ECH) were used in the treatment of humic acid-kaolin simulated water by coagulation-ultrafiltration (C-UF) hybrid process. Coagulation performance, floc characteristics, including floc size, compact degree, and strength were investigated in this study. Ultrafiltration experiments were conducted by a dead-end batch unit to implement the resistance analyses to explore the membrane fouling mechanisms. Results showed that DAM-ECH aid significantly increased the UV254 and DOC removal efficiencies and contributed to the formation of larger and stronger flocs with a looser structure. Aluminum chloride (Al) gave rise to better coagulation performance with DAM-ECH compared with poly aluminum chloride (PACl). The consequences of ultrafiltration experiments showed that DAM-ECH aid could reduce the membrane fouling mainly by decreasing the cake layer resistance. The flux reductions for PACl, Al/DAM-ECH (dosing both Al and DAM-ECH) and PACl/DAM-ECH (dosing both PACl and DAM-ECH) were 62%, 56% and 44%, respectively. Results of this study would be beneficial for the application of PACl/DAM-ECH and Al/DAM-ECH composite coagulants in water treatment processes. PMID:27295439

  20. Measuring ammonia concentration over a grassland near livestock facilities using a semiconductor ammonia sensor

    NASA Astrophysics Data System (ADS)

    Kawashima, S.; Yonemura, S.

    We demonstrated the effectiveness of a semiconductor ammonia sensor capable of performing diachronic measurements; its characteristics were checked in the laboratory by means including comparison with standard gases. We found as a result that the ammonia sensor's readings increased with increasing water vapor pressure. We compared sensor readings with values obtained by chemical analysis of samples collected in situ and checked sensor reading accuracy. Ammonia concentration was determined by combining ammonia sensor readings with measured values for water vapor pressure. In situ conditions were ammonia concentration of under 100 ppbv and water vapor pressure of 4-16 hPa. There was a good correlation with the concentration of samples trapped with boric acid and analyzed by indophenol colorimetry. We discerned a relationship between ammonia concentration and local meteorological conditions such as wind direction and speed. The estimated error of the ammonia sensor's measurements was ±9.7 ppbv when ammonia concentration as measured by acid sampling and colorimetry was regarded as correct. This demonstrated that it is possible to detect in situ fluctuations in low ammonia concentrations of about 10 ppbv, which was the background concentration in farming areas. We have shown a monitoring method for ammonia in situ that is both easy to operate and low-cost.

  1. Versatile microanalytical system with porous polypropylene capillary membrane for calibration gas generation and trace gaseous pollutants sampling applied to the analysis of formaldehyde, formic acid, acetic acid and ammonia in outdoor air.

    PubMed

    Coelho, Lúcia H G; Melchert, Wanessa R; Rocha, Flavio R; Rocha, Fábio R P; Gutz, Ivano G R

    2010-11-15

    The analytical determination of atmospheric pollutants still presents challenges due to the low-level concentrations (frequently in the μg m(-3) range) and their variations with sampling site and time. In this work, a capillary membrane diffusion scrubber (CMDS) was scaled down to match with capillary electrophoresis (CE), a quick separation technique that requires nothing more than some nanoliters of sample and, when combined with capacitively coupled contactless conductometric detection (C(4)D), is particularly favorable for ionic species that do not absorb in the UV-vis region, like the target analytes formaldehyde, formic acid, acetic acid and ammonium. The CMDS was coaxially assembled inside a PTFE tube and fed with acceptor phase (deionized water for species with a high Henry's constant such as formaldehyde and carboxylic acids, or acidic solution for ammonia sampling with equilibrium displacement to the non-volatile ammonium ion) at a low flow rate (8.3 nL s(-1)), while the sample was aspirated through the annular gap of the concentric tubes at 2.5 mL s(-1). A second unit, in all similar to the CMDS, was operated as a capillary membrane diffusion emitter (CMDE), generating a gas flow with know concentrations of ammonia for the evaluation of the CMDS. The fluids of the system were driven with inexpensive aquarium air pumps, and the collected samples were stored in vials cooled by a Peltier element. Complete protocols were developed for the analysis, in air, of NH(3), CH(3)COOH, HCOOH and, with a derivatization setup, CH(2)O, by associating the CMDS collection with the determination by CE-C(4)D. The ammonia concentrations obtained by electrophoresis were checked against the reference spectrophotometric method based on Berthelot's reaction. Sensitivity enhancements of this reference method were achieved by using a modified Berthelot reaction, solenoid micro-pumps for liquid propulsion and a long optical path cell based on a liquid core waveguide (LCW). All

  2. Activity of citrulline malate on acid-base balance and blood ammonia and amino acid levels. Study in the animal and in man.

    PubMed

    Callis, A; Magnan de Bornier, B; Serrano, J J; Bellet, H; Saumade, R

    1991-06-01

    An experimental evaluation of citrulline malate (Stimol, CAS 54940-97-5), an anti-fatigue compound, was undertaken in man and in the animal in order to study the pharmacological activity of the substance at hepatic and renal level. In man, the protocol involved a double-blind randomized, placebo-controlled cross-over technique. The study in the animal was blind and placebo-controlled with two randomized parallel groups. Results showed that citrulline malate stimulates hepatic ureogenesis and favorizes the renal reabsorption of bicarbonates. These metabolic actions had a protective effect against acidosis and ammonia poisoning and explain the anti-fatigue properties of citrulline malate in man. PMID:1930358

  3. Rhodotorula glutinis Phenylalanine/Tyrosine Ammonia Lyase Enzyme Catalyzed Synthesis of the Methyl Ester of para-Hydroxycinnamic Acid and its Potential Antibacterial Activity.

    PubMed

    MacDonald, Marybeth C; Arivalagan, Pugazhendhi; Barre, Douglas E; MacInnis, Judith A; D'Cunha, Godwin B

    2016-01-01

    Biotransformation of L-tyrosine methyl ester (L-TM) to the methyl ester of para- hydroxycinnamic acid (p-HCAM) using Rhodotorula glutinis yeast phenylalanine/tyrosine ammonia lyase (PTAL; EC 4.3.1.26) enzyme was successfully demonstrated for the first time; progress of the reaction was followed by spectrophotometric determination at 315 nm. The following conditions were optimized for maximal formation of p-HCAM: pH (8.5), temperature (37°C), speed of agitation (50 rpm), enzyme concentration (0.080 μM), and substrate concentration (0.50 mM). Under these conditions, the yield of the reaction was ∼15% in 1 h incubation period and ∼63% after an overnight (∼18 h) incubation period. The product (p-HCAM) of the reaction of PTAL with L-TM was confirmed using Nuclear Magnetic Resonance spectroscopy (NMR). Fourier Transform Infra-Red spectroscopy (FTIR) was carried out to rule out potential hydrolysis of p-HCAM during overnight incubation. Potential antibacterial activity of p-HCAM was tested against several strains of Gram-positive and Gram-negative bacteria. This study describes a synthetically useful transformation, and could have future clinical and industrial applications.

  4. Rhodotorula glutinis Phenylalanine/Tyrosine Ammonia Lyase Enzyme Catalyzed Synthesis of the Methyl Ester of para-Hydroxycinnamic Acid and its Potential Antibacterial Activity

    PubMed Central

    MacDonald, Marybeth C.; Arivalagan, Pugazhendhi; Barre, Douglas E.; MacInnis, Judith A.; D’Cunha, Godwin B.

    2016-01-01

    Biotransformation of L-tyrosine methyl ester (L-TM) to the methyl ester of para- hydroxycinnamic acid (p-HCAM) using Rhodotorula glutinis yeast phenylalanine/tyrosine ammonia lyase (PTAL; EC 4.3.1.26) enzyme was successfully demonstrated for the first time; progress of the reaction was followed by spectrophotometric determination at 315 nm. The following conditions were optimized for maximal formation of p-HCAM: pH (8.5), temperature (37°C), speed of agitation (50 rpm), enzyme concentration (0.080 μM), and substrate concentration (0.50 mM). Under these conditions, the yield of the reaction was ∼15% in 1 h incubation period and ∼63% after an overnight (∼18 h) incubation period. The product (p-HCAM) of the reaction of PTAL with L-TM was confirmed using Nuclear Magnetic Resonance spectroscopy (NMR). Fourier Transform Infra-Red spectroscopy (FTIR) was carried out to rule out potential hydrolysis of p-HCAM during overnight incubation. Potential antibacterial activity of p-HCAM was tested against several strains of Gram-positive and Gram-negative bacteria. This study describes a synthetically useful transformation, and could have future clinical and industrial applications. PMID:27014206

  5. Calcium alginate bead immobilization of cells containing tyrosine ammonia lyase activity for use in the production of p-hydroxycinnamic acid.

    PubMed

    Trotman, Robert J; Camp, Carl E; Ben-Bassat, Arie; DiCosimo, Robert; Huang, Lixuan; Crum, Grace A; Sariaslani, F Sima; Haynie, Sharon L

    2007-01-01

    An Escherichia coli catalyst with tyrosine ammonia lyase activity (TAL) has been stabilized for repeated use in batch conversions of high tyrosine solids to p-hydroxycinnamic acid (pHCA). The TAL biocatalyst was stabilized by controlling the reaction pH to 9.8 +/- 0.1 and immobilizing the cells within a calcium alginate matrix that was cross-linked with glutaraldehyde and polyethyleneimine (GA/PEI). We found a GA range where the bead-encapsulated TAL was not inactivated, and the resulting cross-linking provided the beads with the mechanical stability necessary for repeated use in consecutive batch reactions with catalyst recycle. The GA/PEI calcium alginate TAL catalyst was used in 41 1-L batch reactions where 50 g L(-1) tyrosine was converted to 39 +/- 4 g L(-1) pHCA in each batch. The practical usefulness and ease of this process was demonstrated by scaling up the TAL bead immobilization and using the immobilized TAL catalyst in four 125-L bioconversion reactions to produce over 12 kg of purified pHCA.

  6. Tropospheric Emission Spectrometer (TES) satellite observations of ammonia, methanol, formic acid, and carbon monoxide over the Canadian oil sands: validation and model evaluation

    NASA Astrophysics Data System (ADS)

    Shephard, M. W.; McLinden, C. A.; Cady-Pereira, K. E.; Luo, M.; Moussa, S. G.; Leithead, A.; Liggio, J.; Staebler, R. M.; Akingunola, A.; Makar, P.; Lehr, P.; Zhang, J.; Henze, D. K.; Millet, D. B.; Bash, J. O.; Zhu, L.; Wells, K. C.; Capps, S. L.; Chaliyakunnel, S.; Gordon, M.; Hayden, K.; Brook, J. R.; Wolde, M.; Li, S.-M.

    2015-12-01

    The wealth of air quality information provided by satellite infrared observations of ammonia (NH3), carbon monoxide (CO), formic acid (HCOOH), and methanol (CH3OH) is currently being explored and used for a number of applications, especially at regional or global scales. These applications include air quality monitoring, trend analysis, emissions, and model evaluation. This study provides one of the first direct validations of Tropospheric Emission Spectrometer (TES) satellite-retrieved profiles of NH3, CH3OH, and HCOOH through comparisons with coincident aircraft profiles. The comparisons are performed over the Canadian oil sands region during the intensive field campaign (August-September, 2013) in support of the Joint Canada-Alberta Implementation Plan for Oil Sands Monitoring (JOSM). The satellite/aircraft comparisons over this region during this period produced errors of (i) +0.08 ± 0.25 ppbv for NH3, (ii) +7.5 ± 23 ppbv for CO, (iii) +0.19 ± 0.46 ppbv for HCOOH, and (iv) -1.1 ± 0.39 ppbv for CH3OH. These values mostly agree with previously estimated retrieval errors; however, the relatively large negative bias in CH3OH and the significantly greater positive bias for larger HCOOH and CO values observed during this study warrant further investigation. Satellite and aircraft ammonia observations during the field campaign are also used in an initial effort to perform preliminary evaluations of Environment Canada's Global Environmental Multi-scale - Modelling Air quality and CHemistry (GEM-MACH) air quality modelling system at high resolution (2.5 × 2.5 km2). These initial results indicate a model underprediction of ~ 0.6 ppbv (~ 60 %) for NH3, during the field campaign period. The TES/model CO comparison differences are ~ +20 ppbv (~ +20 %), but given that under these conditions the TES/aircraft comparisons also show a small positive TES CO bias indicates that the overall model underprediction of CO is closer to ~ 10 % at 681 hPa (~ 3 km) during this period.

  7. Differential inductions of phenylalanine ammonia-lyase and chalcone synthase during wounding, salicylic acid treatment, and salinity stress in safflower, Carthamus tinctorius.

    PubMed

    Dehghan, Sara; Sadeghi, Mahnaz; Pöppel, Anne; Fischer, Rainer; Lakes-Harlan, Reinhard; Kavousi, Hamid Reza; Vilcinskas, Andreas; Rahnamaeian, Mohammad

    2014-01-01

    Safflower (Carthamus tinctorius L.) serves as a reference dicot for investigation of defence mechanisms in Asteraceae due to abundant secondary metabolites and high resistance/tolerance to environmental stresses. In plants, phenylpropanoid and flavonoid pathways are considered as two central defence signalling cascades in stress conditions. Here, we describe the isolation of two major genes in these pathways, CtPAL (phenylalanine ammonia-lyase) and CtCHS (chalcone synthase) in safflower along with monitoring their expression profiles in different stress circumstances. The aa (amino acid) sequence of isolated region of CtPAL possesses the maximum identity up to 96% to its orthologue in Cynara scolymus, while that of CtCHS retains the highest identity to its orthologue in Callistephus chinensis up to 96%. Experiments for gene expression profiling of CtPAL and CtCHS were performed after the treatment of seedlings with 0.1 and 1 mM SA (salicylic acid), wounding and salinity stress. The results of semi-quantitative RT-PCR revealed that both CtPAL and CtCHS genes are further responsive to higher concentration of SA with dissimilar patterns. Regarding wounding stress, CtPAL gets slightly induced upon injury at 3 hat (hours after treatment) (hat), whereas CtCHS gets greatly induced at 3 hat and levels off gradually afterward. Upon salinity stress, CtPAL displays a similar expression pattern by getting slightly induced at 3 hat, but CtCHS exhibits a biphasic expression profile with two prominent peaks at 3 and 24 hat. These results substantiate the involvement of phenylpropanoid and particularly flavonoid pathways in safflower during wounding and especially salinity stress. PMID:24865400

  8. Differential inductions of phenylalanine ammonia-lyase and chalcone synthase during wounding, salicylic acid treatment, and salinity stress in safflower, Carthamus tinctorius

    PubMed Central

    Dehghan, Sara; Sadeghi, Mahnaz; Pöppel, Anne; Fischer, Rainer; Lakes-Harlan, Reinhard; Kavousi, Hamid Reza; Vilcinskas, Andreas; Rahnamaeian, Mohammad

    2014-01-01

    Safflower (Carthamus tinctorius L.) serves as a reference dicot for investigation of defence mechanisms in Asteraceae due to abundant secondary metabolites and high resistance/tolerance to environmental stresses. In plants, phenylpropanoid and flavonoid pathways are considered as two central defence signalling cascades in stress conditions. Here, we describe the isolation of two major genes in these pathways, CtPAL (phenylalanine ammonia-lyase) and CtCHS (chalcone synthase) in safflower along with monitoring their expression profiles in different stress circumstances. The aa (amino acid) sequence of isolated region of CtPAL possesses the maximum identity up to 96% to its orthologue in Cynara scolymus, while that of CtCHS retains the highest identity to its orthologue in Callistephus chinensis up to 96%. Experiments for gene expression profiling of CtPAL and CtCHS were performed after the treatment of seedlings with 0.1 and 1 mM SA (salicylic acid), wounding and salinity stress. The results of semi-quantitative RT–PCR revealed that both CtPAL and CtCHS genes are further responsive to higher concentration of SA with dissimilar patterns. Regarding wounding stress, CtPAL gets slightly induced upon injury at 3 hat (hours after treatment) (hat), whereas CtCHS gets greatly induced at 3 hat and levels off gradually afterward. Upon salinity stress, CtPAL displays a similar expression pattern by getting slightly induced at 3 hat, but CtCHS exhibits a biphasic expression profile with two prominent peaks at 3 and 24 hat. These results substantiate the involvement of phenylpropanoid and particularly flavonoid pathways in safflower during wounding and especially salinity stress. PMID:24865400

  9. Differential inductions of phenylalanine ammonia-lyase and chalcone synthase during wounding, salicylic acid treatment, and salinity stress in safflower, Carthamus tinctorius.

    PubMed

    Dehghan, Sara; Sadeghi, Mahnaz; Pöppel, Anne; Fischer, Rainer; Lakes-Harlan, Reinhard; Kavousi, Hamid Reza; Vilcinskas, Andreas; Rahnamaeian, Mohammad

    2014-06-25

    Safflower (Carthamus tinctorius L.) serves as a reference dicot for investigation of defence mechanisms in Asteraceae due to abundant secondary metabolites and high resistance/tolerance to environmental stresses. In plants, phenylpropanoid and flavonoid pathways are considered as two central defence signalling cascades in stress conditions. Here, we describe the isolation of two major genes in these pathways, CtPAL (phenylalanine ammonia-lyase) and CtCHS (chalcone synthase) in safflower along with monitoring their expression profiles in different stress circumstances. The aa (amino acid) sequence of isolated region of CtPAL possesses the maximum identity up to 96% to its orthologue in Cynara scolymus, while that of CtCHS retains the highest identity to its orthologue in Callistephus chinensis up to 96%. Experiments for gene expression profiling of CtPAL and CtCHS were performed after the treatment of seedlings with 0.1 and 1 mM SA (salicylic acid), wounding and salinity stress. The results of semi-quantitative RT-PCR revealed that both CtPAL and CtCHS genes are further responsive to higher concentration of SA with dissimilar patterns. Regarding wounding stress, CtPAL gets slightly induced upon injury at 3 hat (hours after treatment) (hat), whereas CtCHS gets greatly induced at 3 hat and levels off gradually afterward. Upon salinity stress, CtPAL displays a similar expression pattern by getting slightly induced at 3 hat, but CtCHS exhibits a biphasic expression profile with two prominent peaks at 3 and 24 hat. These results substantiate the involvement of phenylpropanoid and particularly flavonoid pathways in safflower during wounding and especially salinity stress.

  10. Measuring ammonia from space: limits and possibilities

    NASA Astrophysics Data System (ADS)

    Cady-Pereira, K. E.; Pinder, R. W.; Walker, J. T.; Bash, J. O.; Luo, M.; Henze, D. K.; Shephard, M. W.; Zhu, J.; Rinsland, C.

    2010-12-01

    Ammonia (NH3) is an important component in local, regional, and global tropospheric chemistry. Ammonia contributes significantly to several well-known environmental problems: excess deposition in terrestrial ecosystems can lead to soil acidification and loss of plant diversity, while in coastal ecosystems, it can cause eutrophication, algal blooms, and loss of fish and shellfish. In the atmosphere NH3 can combine with sulfates and nitric acid to form ammonium nitrate and ammonium sulfate, which constitute a substantial fraction of fine particulate matter (PM2.5). Nevertheless, there is great uncertainty in the magnitude and in the spatial/seasonal variability of ammonia concentrations and emissions. Retrievals of ammonia from spectra obtained from the Tropospheric Emission Spectrometer (TES) flying on the AURA satellite have the potential of significantly increasing our knowledge of the spatial and temporal variability of ammonia and of providing constraints on ammonia emissions through the use of inverse models at both the regional and global scales. We will present an updated evaluation of the TES ammonia retrievals using sensitivity studies, simulations, and in situ observations. We will demonstrate TES’ capability to discern spatial gradients and temporal variability in ammonia concentrations, with results from the TES transects over the Central Valley and North Carolina, as well as monthly means from TES global surveys. We will also show an example of using TES NH3 measurements to constrain surface emissions over North America.

  11. [Phenylalanine ammonia-lyase of pigmented yeasts].

    PubMed

    Mushi, N Iu; Kupletskaia, M B; Bab'eva, I P; Egorov, N S

    1980-01-01

    116 pigmented yeast cultures were tested for the presence of L-phenylalanine-ammonia lyase transforming L-phenylalanine into trans-cinnamic acid. The enzyme was found in 54 strains. Most of these strains belonged to the genera Rhodotorula and Sporobolomyces. Toluene, along with acetone, was successfully used to increase cellular permeability of the yeast cultures while determining the activity of phenylalanine-ammonia lyase.

  12. Analysis of trifluralin, methyl paraoxon, methyl parathion, fenvalerate and 2,4-D dimethylamine in pond water using solid-phase extraction

    USGS Publications Warehouse

    Swineford, D.M.; Belisle, A.A.

    1989-01-01

    A method was developed for the simultaneous extraction of trifluralin, methyl paraoxon, methyl parathion, fenvalerate, and 2,4-D dimethylamine salt in pond water using a solid-phase C18 column. After elution from the C18 column, the eluate was analyzed on a capillary gas chromatograph equipped with an electron-capture or flame photometric detector.

  13. Molecular understanding of atmospheric particle formation from sulfuric acid and large oxidized organic molecules.

    PubMed

    Schobesberger, Siegfried; Junninen, Heikki; Bianchi, Federico; Lönn, Gustaf; Ehn, Mikael; Lehtipalo, Katrianne; Dommen, Josef; Ehrhart, Sebastian; Ortega, Ismael K; Franchin, Alessandro; Nieminen, Tuomo; Riccobono, Francesco; Hutterli, Manuel; Duplissy, Jonathan; Almeida, João; Amorim, Antonio; Breitenlechner, Martin; Downard, Andrew J; Dunne, Eimear M; Flagan, Richard C; Kajos, Maija; Keskinen, Helmi; Kirkby, Jasper; Kupc, Agnieszka; Kürten, Andreas; Kurtén, Theo; Laaksonen, Ari; Mathot, Serge; Onnela, Antti; Praplan, Arnaud P; Rondo, Linda; Santos, Filipe D; Schallhart, Simon; Schnitzhofer, Ralf; Sipilä, Mikko; Tomé, António; Tsagkogeorgas, Georgios; Vehkamäki, Hanna; Wimmer, Daniela; Baltensperger, Urs; Carslaw, Kenneth S; Curtius, Joachim; Hansel, Armin; Petäjä, Tuukka; Kulmala, Markku; Donahue, Neil M; Worsnop, Douglas R

    2013-10-22

    Atmospheric aerosols formed by nucleation of vapors affect radiative forcing and therefore climate. However, the underlying mechanisms of nucleation remain unclear, particularly the involvement of organic compounds. Here, we present high-resolution mass spectra of ion clusters observed during new particle formation experiments performed at the Cosmics Leaving Outdoor Droplets chamber at the European Organization for Nuclear Research. The experiments involved sulfuric acid vapor and different stabilizing species, including ammonia and dimethylamine, as well as oxidation products of pinanediol, a surrogate for organic vapors formed from monoterpenes. A striking resemblance is revealed between the mass spectra from the chamber experiments with oxidized organics and ambient data obtained during new particle formation events at the Hyytiälä boreal forest research station. We observe that large oxidized organic compounds, arising from the oxidation of monoterpenes, cluster directly with single sulfuric acid molecules and then form growing clusters of one to three sulfuric acid molecules plus one to four oxidized organics. Most of these organic compounds retain 10 carbon atoms, and some of them are remarkably highly oxidized (oxygen-to-carbon ratios up to 1.2). The average degree of oxygenation of the organic compounds decreases while the clusters are growing. Our measurements therefore connect oxidized organics directly, and in detail, with the very first steps of new particle formation and their growth between 1 and 2 nm in a controlled environment. Thus, they confirm that oxidized organics are involved in both the formation and growth of particles under ambient conditions.

  14. The effect of acid-base clustering and ions on the growth of atmospheric nano-particles.

    PubMed

    Lehtipalo, Katrianne; Rondo, Linda; Kontkanen, Jenni; Schobesberger, Siegfried; Jokinen, Tuija; Sarnela, Nina; Kürten, Andreas; Ehrhart, Sebastian; Franchin, Alessandro; Nieminen, Tuomo; Riccobono, Francesco; Sipilä, Mikko; Yli-Juuti, Taina; Duplissy, Jonathan; Adamov, Alexey; Ahlm, Lars; Almeida, João; Amorim, Antonio; Bianchi, Federico; Breitenlechner, Martin; Dommen, Josef; Downard, Andrew J; Dunne, Eimear M; Flagan, Richard C; Guida, Roberto; Hakala, Jani; Hansel, Armin; Jud, Werner; Kangasluoma, Juha; Kerminen, Veli-Matti; Keskinen, Helmi; Kim, Jaeseok; Kirkby, Jasper; Kupc, Agnieszka; Kupiainen-Määttä, Oona; Laaksonen, Ari; Lawler, Michael J; Leiminger, Markus; Mathot, Serge; Olenius, Tinja; Ortega, Ismael K; Onnela, Antti; Petäjä, Tuukka; Praplan, Arnaud; Rissanen, Matti P; Ruuskanen, Taina; Santos, Filipe D; Schallhart, Simon; Schnitzhofer, Ralf; Simon, Mario; Smith, James N; Tröstl, Jasmin; Tsagkogeorgas, Georgios; Tomé, António; Vaattovaara, Petri; Vehkamäki, Hanna; Vrtala, Aron E; Wagner, Paul E; Williamson, Christina; Wimmer, Daniela; Winkler, Paul M; Virtanen, Annele; Donahue, Neil M; Carslaw, Kenneth S; Baltensperger, Urs; Riipinen, Ilona; Curtius, Joachim; Worsnop, Douglas R; Kulmala, Markku

    2016-05-20

    The growth of freshly formed aerosol particles can be the bottleneck in their survival to cloud condensation nuclei. It is therefore crucial to understand how particles grow in the atmosphere. Insufficient experimental data has impeded a profound understanding of nano-particle growth under atmospheric conditions. Here we study nano-particle growth in the CLOUD (Cosmics Leaving OUtdoors Droplets) chamber, starting from the formation of molecular clusters. We present measured growth rates at sub-3 nm sizes with different atmospherically relevant concentrations of sulphuric acid, water, ammonia and dimethylamine. We find that atmospheric ions and small acid-base clusters, which are not generally accounted for in the measurement of sulphuric acid vapour, can participate in the growth process, leading to enhanced growth rates. The availability of compounds capable of stabilizing sulphuric acid clusters governs the magnitude of these effects and thus the exact growth mechanism. We bring these observations into a coherent framework and discuss their significance in the atmosphere.

  15. The effect of acid-base clustering and ions on the growth of atmospheric nano-particles.

    PubMed

    Lehtipalo, Katrianne; Rondo, Linda; Kontkanen, Jenni; Schobesberger, Siegfried; Jokinen, Tuija; Sarnela, Nina; Kürten, Andreas; Ehrhart, Sebastian; Franchin, Alessandro; Nieminen, Tuomo; Riccobono, Francesco; Sipilä, Mikko; Yli-Juuti, Taina; Duplissy, Jonathan; Adamov, Alexey; Ahlm, Lars; Almeida, João; Amorim, Antonio; Bianchi, Federico; Breitenlechner, Martin; Dommen, Josef; Downard, Andrew J; Dunne, Eimear M; Flagan, Richard C; Guida, Roberto; Hakala, Jani; Hansel, Armin; Jud, Werner; Kangasluoma, Juha; Kerminen, Veli-Matti; Keskinen, Helmi; Kim, Jaeseok; Kirkby, Jasper; Kupc, Agnieszka; Kupiainen-Määttä, Oona; Laaksonen, Ari; Lawler, Michael J; Leiminger, Markus; Mathot, Serge; Olenius, Tinja; Ortega, Ismael K; Onnela, Antti; Petäjä, Tuukka; Praplan, Arnaud; Rissanen, Matti P; Ruuskanen, Taina; Santos, Filipe D; Schallhart, Simon; Schnitzhofer, Ralf; Simon, Mario; Smith, James N; Tröstl, Jasmin; Tsagkogeorgas, Georgios; Tomé, António; Vaattovaara, Petri; Vehkamäki, Hanna; Vrtala, Aron E; Wagner, Paul E; Williamson, Christina; Wimmer, Daniela; Winkler, Paul M; Virtanen, Annele; Donahue, Neil M; Carslaw, Kenneth S; Baltensperger, Urs; Riipinen, Ilona; Curtius, Joachim; Worsnop, Douglas R; Kulmala, Markku

    2016-01-01

    The growth of freshly formed aerosol particles can be the bottleneck in their survival to cloud condensation nuclei. It is therefore crucial to understand how particles grow in the atmosphere. Insufficient experimental data has impeded a profound understanding of nano-particle growth under atmospheric conditions. Here we study nano-particle growth in the CLOUD (Cosmics Leaving OUtdoors Droplets) chamber, starting from the formation of molecular clusters. We present measured growth rates at sub-3 nm sizes with different atmospherically relevant concentrations of sulphuric acid, water, ammonia and dimethylamine. We find that atmospheric ions and small acid-base clusters, which are not generally accounted for in the measurement of sulphuric acid vapour, can participate in the growth process, leading to enhanced growth rates. The availability of compounds capable of stabilizing sulphuric acid clusters governs the magnitude of these effects and thus the exact growth mechanism. We bring these observations into a coherent framework and discuss their significance in the atmosphere. PMID:27197574

  16. Sources and sinks for ammonia and nitrite on the early Earth and the reaction of nitrite with ammonia

    NASA Technical Reports Server (NTRS)

    Summers, D. P.

    1999-01-01

    An analysis of sources and sinks for ammonia and nitrite on the early Earth was conducted. Rates of formation and destruction, and steady state concentrations of both species were determined by steady state kinetics. The importance of the reaction of nitrite with ammonia on the feasibility of ammonia formation from nitrite was evaluated. The analysis considered conditions such as temperature, ferrous iron concentration, and pH. For sinks we considered the reduction of nitrite to ammonia, reaction between nitrite and ammonia, photochemical destruction of both species, and destruction at hydrothermal vents. Under most environmental conditions, the primary sink for nitrite is reduction to ammonia. The reaction between ammonia and nitrite is not an important sink for either nitrite or ammonia. Destruction at hydrothermal vents is important at acidic pH's and at low ferrous iron concentrations. Photochemical destruction, even in a worst case scenario, is unimportant under many conditions except possibly under acidic, low iron concentration, or low temperature conditions. The primary sink for ammonia is photochemical destruction in the atmosphere. Under acidic conditions, more of the ammonia is tied up as ammonium (reducing its vapor pressure and keeping it in solution) and hydrothermal destruction becomes more important.

  17. AMBIENT AMMONIA AND AMMONIUM AEROSOL ACROSS A REGION OF VARIABLE AMMONIA EMISSION DENSITY

    EPA Science Inventory

    The paper presents one year of ambient ammonia (NH3), ammonium (NH4+), hydrochloric acid (HCI), chloride (CI¯), nitric acid (HNO3), nitrate (NO3¯), nitrous acid (HONO), sulfur dioxide (SO2), and sulfate (SO4

  18. Sources of atmospheric ammonia

    NASA Technical Reports Server (NTRS)

    Harriss, R. C.; Michaels, J. T.

    1982-01-01

    The information available on factors that influence emissions from the principal societal sources of ammonia to the atmosphere, namely combustion processes, volatilization of farm animal wastes, and volatilization of fertilizers, is reviewed. Emission factors are established for each major source of atmospheric ammonia. The factors are then multiplied by appropriate source characterization descriptors to obtain calculated fluxes of ammonia to the atmosphere on a state-by-state basis for the United States.

  19. Pretreatment of dried distillers grains with solubles by soaking in aqueous ammonia and subsequent enzymatic/dilute acid hydrolysis to produce fermentable sugars

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dried distillers grains with solubles (DDGS), a co-product of corn ethanol production in the dry-grind process, was pretreated by soaking in aqueous ammonia (SAA) using a 15% w/w NH4OH solution at a solid:liquid ratio of 1:10. The effect of pretreatment on subsequent enzymatic hydrolysis was studied...

  20. Nitric oxide scavengers differentially inhibit ammonia oxidation in ammonia-oxidizing archaea and bacteria.

    PubMed

    Sauder, Laura A; Ross, Ashley A; Neufeld, Josh D

    2016-04-01

    Differential inhibitors are important for measuring the relative contributions of microbial groups, such as ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA), to biogeochemical processes in environmental samples. In particular, 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide (PTIO) represents a nitric oxide scavenger used for the specific inhibition of AOA, implicating nitric oxide as an intermediate of thaumarchaeotal ammonia oxidation. This study investigated four alternative nitric oxide scavengers for their ability to differentially inhibit AOA and AOB in comparison to PTIO. Caffeic acid, curcumin, methylene blue hydrate and trolox were tested onNitrosopumilus maritimus, two unpublished AOA representatives (AOA-6f and AOA-G6) as well as the AOB representative Nitrosomonas europaea All four scavengers inhibited ammonia oxidation by AOA at lower concentrations than for AOB. In particular, differential inhibition of AOA and AOB by caffeic acid (100 μM) and methylene blue hydrate (3 μM) was comparable to carboxy-PTIO (100 μM) in pure and enrichment culture incubations. However, when added to aquarium sponge biofilm microcosms, both scavengers were unable to inhibit ammonia oxidation consistently, likely due to degradation of the inhibitors themselves. This study provides evidence that a variety of nitric oxide scavengers result in differential inhibition of ammonia oxidation in AOA and AOB, and provides support to the proposed role of nitric oxide as a key intermediate in the thaumarchaeotal ammonia oxidation pathway.

  1. Photosynthesis of ammonia

    SciTech Connect

    Mallow, W.A.

    1984-09-24

    This study has demonstrated the technical feasibility of producing ammonia using an innovative technique of combining air, water and sunlight. The technique involves passing moist air over a catalyst-doped, open-celled silica foam bed illuminated by concentrated sunlight. A catalytic reaction results in tounts of ammonia. The work summarized in this report included testing of a pilot (small scale) ammonia production system located on the roof of a Southwest Research Institute (SwRI) Laboratory located in San Antonio, Texas. The system consisted of a catalyst foam bed located in a glass tube about three meters long and 5 centimeters in diameter and mounted on the focal line of a parabolic trough solar collector focused at the sun. The primary active ingredient in the catalyst was titanium dioxide. Moist air was blown through the glass tube, over illuminated catalyst foam bed. A catalytic reaction took place in the foam bed resulting in the production of ammonia gas. The ammonia gas was bubbled through a water scrubber where the ammonia was dissolved. The ammonia concentration in the scrubber water was then measured using chemiluminescence and spectrophotometry techniques to determine the ammonia production rate. Thirty-one tests were conducted in the roof top facility. A number of important process parameters were evaluated. The ammonia production rate from these tests varied from several milligrams per hour to a few micrograms per hour. The tests showed that ammonia production was possible although the yields were relatively low. Several aspects of the process could be improved to increase the yield rates. Specifically, better techniques for illuminating the catalyst with concentrated sunlight and for providing moisture at the catalyst surface should enhance the ammonia production rate. 13 references, 7 figures, 1 table.

  2. Method for forming ammonia

    DOEpatents

    Kong, Peter C.; Pink, Robert J.; Zuck, Larry D.

    2008-08-19

    A method for forming ammonia is disclosed and which includes the steps of forming a plasma; providing a source of metal particles, and supplying the metal particles to the plasma to form metal nitride particles; and providing a substance, and reacting the metal nitride particles with the substance to produce ammonia, and an oxide byproduct.

  3. Assessing Ammonia Treatment Options

    EPA Science Inventory

    This is the second of three articles to help water system operators understand ammonia and how to monitor and control its effects at the plant and in the distribution system. The first article (Opflow, April 2012) provided an overview of ammonia's chemistry, origins, and water sy...

  4. Hydrogen generation from alcohols (α-hydroxy carboxylic acids) and alcohol-ammonia coupling in aqueous media catalysed by water-soluble bipyridine-Cp*Ir (Rh or Os) catalyst: a computational mechanism insight

    NASA Astrophysics Data System (ADS)

    Zhang, Dan-Dan; Chen, Xian-Kai; Liu, Hui-Ling; Huang, Xu-Ri

    2015-06-01

    Density functional theory (DFT) calculations were performed to elucidate the mechanism of the dehydrogenative oxidation of various primary alcohols (or α-hydroxy carboxylic acids) and the dehydrogenative coupling of alcohols with ammonia catalysed by the same water-soluble Cp*Ir complex bearing a 2-pyridonate-based ligand (A-Ir). Another two new catalysts A-Rh and A-Os are computationally designed for the dehydrogenative oxidation of alcohols. The plausible pathway for alcohol dehydrogenation includes three steps: alcohol oxidation to aldehyde (step I); the generation of dihydrogen in the metal coordination sphere (step II); and the liberation of dihydrogen accompanied with the regeneration of active catalyst A (step III). Among them, the step I follows bifunctional concerted double hydrogen transfer mechanism rather than the β-H elimination. For step II, the energy barriers involving the addition of one or two water molecules are higher than in absence of water. Our results also confirm that A-Ir can be applied in the dehydrogenation of various α-hydroxy carboxylic acids by the similar mechanism. Remarkably, A-Ir is also found to be efficient for the coupling reactions of various primary benzyl alcohols with ammonia to afford amides.

  5. Phenylalanine Ammonia-Lyase-Catalyzed Deamination of an Acyclic Amino Acid: Enzyme Mechanistic Studies Aided by a Novel Microreactor Filled with Magnetic Nanoparticles.

    PubMed

    Weiser, Diána; Bencze, László Csaba; Bánóczi, Gergely; Ender, Ferenc; Kiss, Róbert; Kókai, Eszter; Szilágyi, András; Vértessy, Beáta G; Farkas, Ödön; Paizs, Csaba; Poppe, László

    2015-11-01

    Phenylalanine ammonia-lyase (PAL), found in many organisms, catalyzes the deamination of l-phenylalanine (Phe) to (E)-cinnamate by the aid of its MIO prosthetic group. By using PAL immobilized on magnetic nanoparticles and fixed in a microfluidic reactor with an in-line UV detector, we demonstrated that PAL can catalyze ammonia elimination from the acyclic propargylglycine (PG) to yield (E)-pent-2-ene-4-ynoate. This highlights new opportunities to extend MIO enzymes towards acyclic substrates. As PG is acyclic, its deamination cannot involve a Friedel-Crafts-type attack at an aromatic ring. The reversibility of the PAL reaction, demonstrated by the ammonia addition to (E)-pent-2-ene-4-ynoate yielding enantiopure l-PG, contradicts the proposed highly exothermic single-step mechanism. Computations with the QM/MM models of the N-MIO intermediates from L-PG and L-Phe in PAL show similar arrangements within the active site, thus supporting a mechanism via the N-MIO intermediate.

  6. Ammonia transport in the kidney by Rhesus glycoproteins

    PubMed Central

    Verlander, Jill W.

    2014-01-01

    Renal ammonia metabolism is a fundamental element of acid-base homeostasis, comprising a major component of both basal and physiologically altered renal net acid excretion. Over the past several years, a fundamental change in our understanding of the mechanisms of renal epithelial cell ammonia transport has occurred, replacing the previous model which was based upon diffusion equilibrium for NH3 and trapping of NH4+ with a new model in which specific and regulated transport of both NH3 and NH4+ across renal epithelial cell membranes via specific membrane proteins is required for normal ammonia metabolism. A major advance has been the recognition that members of a recently recognized transporter family, the Rhesus glycoprotein family, mediate critical roles in renal and extrarenal ammonia transport. The erythroid-specific Rhesus glycoprotein, Rh A Glycoprotein (Rhag), was the first Rhesus glycoprotein recognized as an ammonia-specific transporter. Subsequently, the nonerythroid Rh glycoproteins, Rh B Glycoprotein (Rhbg) and Rh C Glycoprotein (Rhcg), were cloned and identified as ammonia transporters. They are expressed in specific cell populations and membrane domains in distal renal epithelial cells, where they facilitate ammonia secretion. In this review, we discuss the distribution of Rhbg and Rhcg in the kidney, the regulation of their expression and activity in physiological disturbances, the effects of genetic deletion on renal ammonia metabolism, and the molecular mechanisms of Rh glycoprotein-mediated ammonia transport. PMID:24647713

  7. Ammonia transport in the kidney by Rhesus glycoproteins.

    PubMed

    Weiner, I David; Verlander, Jill W

    2014-05-15

    Renal ammonia metabolism is a fundamental element of acid-base homeostasis, comprising a major component of both basal and physiologically altered renal net acid excretion. Over the past several years, a fundamental change in our understanding of the mechanisms of renal epithelial cell ammonia transport has occurred, replacing the previous model which was based upon diffusion equilibrium for NH3 and trapping of NH4(+) with a new model in which specific and regulated transport of both NH3 and NH4(+) across renal epithelial cell membranes via specific membrane proteins is required for normal ammonia metabolism. A major advance has been the recognition that members of a recently recognized transporter family, the Rhesus glycoprotein family, mediate critical roles in renal and extrarenal ammonia transport. The erythroid-specific Rhesus glycoprotein, Rh A Glycoprotein (Rhag), was the first Rhesus glycoprotein recognized as an ammonia-specific transporter. Subsequently, the nonerythroid Rh glycoproteins, Rh B Glycoprotein (Rhbg) and Rh C Glycoprotein (Rhcg), were cloned and identified as ammonia transporters. They are expressed in specific cell populations and membrane domains in distal renal epithelial cells, where they facilitate ammonia secretion. In this review, we discuss the distribution of Rhbg and Rhcg in the kidney, the regulation of their expression and activity in physiological disturbances, the effects of genetic deletion on renal ammonia metabolism, and the molecular mechanisms of Rh glycoprotein-mediated ammonia transport.

  8. Ammonia Leak Locator Study

    NASA Technical Reports Server (NTRS)

    Dodge, Franklin T.; Wuest, Martin P.; Deffenbaugh, Danny M.

    1995-01-01

    The thermal control system of International Space Station Alpha will use liquid ammonia as the heat exchange fluid. It is expected that small leaks (of the order perhaps of one pound of ammonia per day) may develop in the lines transporting the ammonia to the various facilities as well as in the heat exchange equipment. Such leaks must be detected and located before the supply of ammonia becomes critically low. For that reason, NASA-JSC has a program underway to evaluate instruments that can detect and locate ultra-small concentrations of ammonia in a high vacuum environment. To be useful, the instrument must be portable and small enough that an astronaut can easily handle it during extravehicular activity. An additional complication in the design of the instrument is that the environment immediately surrounding ISSA will contain small concentrations of many other gases from venting of onboard experiments as well as from other kinds of leaks. These other vapors include water, cabin air, CO2, CO, argon, N2, and ethylene glycol. Altogether, this local environment might have a pressure of the order of 10(exp -7) to 10(exp -6) torr. Southwest Research Institute (SwRI) was contracted by NASA-JSC to provide support to NASA-JSC and its prime contractors in evaluating ammonia-location instruments and to make a preliminary trade study of the advantages and limitations of potential instruments. The present effort builds upon an earlier SwRI study to evaluate ammonia leak detection instruments [Jolly and Deffenbaugh]. The objectives of the present effort include: (1) Estimate the characteristics of representative ammonia leaks; (2) Evaluate the baseline instrument in the light of the estimated ammonia leak characteristics; (3) Propose alternative instrument concepts; and (4) Conduct a trade study of the proposed alternative concepts and recommend promising instruments. The baseline leak-location instrument selected by NASA-JSC was an ion gauge.

  9. Ammonia Release on ISS

    NASA Technical Reports Server (NTRS)

    Macatangay, Ariel

    2009-01-01

    Crew: Approximately 53% metabolic load Product of protein metabolism Limit production of ammonia by external regulation NOT possbile Payloads Potential source Scientific experiments Thorough safety review ensures sufficient levels of containment

  10. Reactor for removing ammonia

    DOEpatents

    Luo, Weifang; Stewart, Kenneth D.

    2009-11-17

    Disclosed is a device for removing trace amounts of ammonia from a stream of gas, particularly hydrogen gas, prepared by a reformation apparatus. The apparatus is used to prevent PEM "poisoning" in a fuel cell receiving the incoming hydrogen stream.

  11. Titan's Ammonia Feature

    NASA Technical Reports Server (NTRS)

    Smythe, W.; Nelson, R.; Boryta, M.; Choukroun, M.

    2011-01-01

    NH3 has long been considered an important component in the formation and evolution of the outer planet satellites. NH3 is particularly important for Titan, since it may serve as the reservoir for atmospheric nitrogen. A brightening seen on Titan starting in 2004 may arise from a transient low-lying fog or surface coating of ammonia. The spectral shape suggests the ammonia is anhydrous, a molecule that hydrates quickly in the presence of water.

  12. Ammonia Clouds on Jupiter

    NASA Technical Reports Server (NTRS)

    2007-01-01

    [figure removed for brevity, see original site] Click on the image for movie of Ammonia Ice Clouds on Jupiter

    In this movie, put together from false-color images taken by the New Horizons Ralph instrument as the spacecraft flew past Jupiter in early 2007, show ammonia clouds (appearing as bright blue areas) as they form and disperse over five successive Jupiter 'days.' Scientists noted how the larger cloud travels along with a small, local deep hole.

  13. Dimethylamine as a major alkyl amine species in particles and cloud water: Observations in semi-arid and coastal regions

    PubMed Central

    Youn, J.-S.; Crosbie, E.; Maudlin, L.C.; Wang, Z.; Sorooshian, A.

    2016-01-01

    Aerosol and cloud water measurements of dimethylamine (DMA), the most abundant amine in this study, were conducted in semi-arid (Tucson, Arizona) and marine (Nucleation in California Experiment, NiCE; central coast of California) areas. In both regions, DMA exhibits a unimodal aerosol mass size distribution with a dominant peak between 0.18 and 0.56 μm. Particulate DMA concentrations increase as a function of marine biogenic emissions, sulfate, BVOC emissions, and aerosol-phase water. Such data supports biogenic sources of DMA, aminium salt formation, and partitioning of DMA to condensed phases. DMA concentrations exhibit positive correlations with various trace elements and most especially vanadium, which warrants additional investigation. Cloud water DMA levels are enhanced significantly during wildfire periods unlike particulate DMA levels, including in droplet residual particles, due to effective dissolution of DMA into cloud water and probably DMA volatilization after drop evaporation. DMA:NH+4 molar ratios peak between 0.18 and 1.0 μm depending on the site and time of year, suggesting that DMA competes better with NH3 in those sizes in terms of reactive uptake by particles. PMID:26807039

  14. Dimethylamine as a Major Alkyl Amine Species in Particles and Cloud Water: Observations in Semi-Arid and Coastal Regions

    NASA Astrophysics Data System (ADS)

    Youn, J. S.; Crosbie, E.; Maudlin, L.; Wang, Z.; Sorooshian, A.

    2015-12-01

    Aerosol and cloud water measurements of dimethylamine (DMA), the most abundant amine in this study, were conducted in semi-arid (Tucson, Arizona) and marine (Nucleation in California Experiment, NiCE; central coast of California) areas. In both regions, DMA exhibits a unimodal mass size distribution with a dominant peak between 0.18 - 0.56 μm. Aminium salt formation is likely the dominant path for DMA into particles, but DMA can partition to coarse particle (e.g., dust, sea salt) surfaces too. The ratio of DMA to ammonium for bulk aerosol reaches up to 8% and 15% for Tucson and NiCE, respectively. Marine biogenic emissions are shown to be a significant source of DMA, with DMA being over three times as high during NiCE versus at Tucson. Wildfires during NiCE did not impact the mass size distribution of particulate DMA; conversely, significant DMA concentration enhancements were observed in cloud water due to dissolution. It is likely that DMA, similar to nitrate, volatilizes after drop evaporation, which is why enhancements were not observed in surface or airborne aerosol measurements. PM1.0 data in Tucson show the following: (i) year-long DMA concentrations are positively correlated with factors that enhance sulfate formation, biogenic volatile organic compound emissions, and aerosol-phase water; and (ii) DMA concentrations exhibit positive correlations with various trace elements, most especially vanadium, which warrants additional investigation.

  15. Dimethylamine as a major alkyl amine species in particles and cloud water: Observations in semi-arid and coastal regions

    NASA Astrophysics Data System (ADS)

    Youn, J.-S.; Crosbie, E.; Maudlin, L. C.; Wang, Z.; Sorooshian, A.

    2015-12-01

    Aerosol and cloud water measurements of dimethylamine (DMA), the most abundant amine in this study, were conducted in semi-arid (Tucson, Arizona) and marine (Nucleation in California Experiment, NiCE; central coast of California) areas. In both regions, DMA exhibits a unimodal aerosol mass size distribution with a dominant peak between 0.18 and 0.56 μm. Particulate DMA concentrations increase as a function of marine biogenic emissions, sulfate, BVOC emissions, and aerosol-phase water. Such data supports biogenic sources of DMA, aminium salt formation, and partitioning of DMA to condensed phases. DMA concentrations exhibit positive correlations with various trace elements and most especially vanadium, which warrants additional investigation. Cloud water DMA levels are enhanced significantly during wildfire periods unlike particulate DMA levels, including in droplet residual particles, due to effective dissolution of DMA into cloud water and probably DMA volatilization after drop evaporation. DMA: NH4+ molar ratios peak between 0.18 and 1.0 μm depending on the site and time of year, suggesting that DMA competes better with NH3 in those sizes in terms of reactive uptake by particles.

  16. Degradation of N-nitrosodimethylamine (NDMA) and its precursor dimethylamine (DMA) in mineral micropores induced by microwave irradiation.

    PubMed

    He, Yuanzhen; Cheng, Hefa

    2016-05-01

    Removal of N-nitrosodimethylamine (NDMA) in drinking water treatment poses a significant technical challenge due to its small molecular size, high polarity and water solubility, and poor biodegradability. Degradation of NDMA and its precursor, dimethylamine (DMA), was investigated by adsorbing them from aqueous solution using porous mineral sorbents, followed by destruction under microwave irradiation. Among the mineral sorbents evaluated, dealuminated ZSM-5 exhibited the highest sorption capacities for NDMA and DMA, which decreased with the density of surface cations present in the micropores. In contrast, the degradation rate of the sorbed NDMA increased with the density of surface cations under microwave irradiation. Evolutions of the degradation products and C/N ratio indicate that the sorbed NDMA and DMA could be eventually mineralized under continuous microwave irradiation. The degradation rate was strongly correlated with the bulk temperature of ZSM-5 and microwave power, which is consistent with the mechanism of pyrolysis caused by formation of micro-scale "hot spots" within the mineral micropores under microwave irradiation. Compared to existing treatment options for NDMA removal, microporous mineral sorption coupled with microwave-induced degradation has the unique advantages of being able to simultaneously remove NDMA and DMA and cause their full mineralization, and thus could serve as a promising alternative method. PMID:26971806

  17. A novel liquid chromatography-mass spectrometric method for the simultaneous determination of trimethylamine, dimethylamine and methylamine in fishery products.

    PubMed

    Baliño-Zuazo, Lander; Barranco, Alejandro

    2016-04-01

    A novel multianalyte method has been developed to determine the concentration of trimethylamine (TMA), dimethylamine (DMA) and methylamine (MA) in fish. The optimal points of the key parameters (pH 8, 60 °C and 60 min of reaction time) were determined for the reaction with tert-butyl bromoacetate. An HILIC column was used to elute all the compounds in only 12 min and selective quantitation of the compounds was achieved. The methodology was validated in trout, hake and Atlantic horse mackerel and was used to study the shelf life of fish under refrigeration. A good correlation with the picrate method was obtained and the proposed methodology has been proved to be robust, specific and sensible with a limit of detection of 0.08 mg N-TMA kg(-1) in freshwater fish and 1 mg N-TMA kg(-1) in marine fish. In addition, TMA has been proved to be a good spoilage indicator also in freshwater fish.

  18. Effect of gaseous ammonia on nicotine sorption

    SciTech Connect

    Webb, A.M.; Singer, B.C.; Nazaroff, W.W.

    2002-06-01

    Nicotine is a major constituent of environmental tobacco smoke. Sorptive interactions of nicotine with indoor surfaces can substantially alter indoor concentrations. The phenomenon is poorly understood, including whether sorption is fully reversible or partially irreversible. They hypothesize that acid-base chemistry on indoor surfaces might contribute to the apparent irreversibility of nicotine sorption under some circumstances. Specifically, they suggest that nicotine may become protonated on surfaces, markedly reducing its vapor pressure. If so, subsequent exposure of the surface to gaseous ammonia, a common base, could raise the surface pH, causing deprotonation and desorption of nicotine from surfaces. A series of experiments was conducted to explore the effect of ammonia on nicotine sorption to and reemission from surfaces. The results indicate that, under some conditions, exposure to gaseous ammonia can substantially increase the rate of desorption of previously sorbed nicotine from common indoor surface materials.

  19. Ammonia diffusion through Nalophan™ bags.

    PubMed

    Sironi, Selena; Eusebio, Lidia; Dentoni, Licinia; Capelli, Laura; Del Rosso, Renato

    2014-01-01

    The aim of the work is to verify the diffusion rate of ammonia through the Nalophan™ film that constitutes the sampling bag, considering storage times ranging from 1 to 26 h. The ammonia decay over time was evaluated using gas-chromatography for the quantification of ammonia concentration inside the bag. The research assesses the roles of both of ammonia and water concentration gradients at the polymeric film interface on the diffusion process. The results show that both the ammonia concentration gradient and, in a less pronounced way, the water concentration gradient are the main 'engines' of ammonia diffusion. Double bags seem to represent a simple solution for preventing ammonia losses during storage. Another interesting result concerns the role of the bag surface on the ammonia diffusion rate: the higher the surface/volume (S/V) ratio, the higher the ammonia diffusion rate through the polymeric film.

  20. Ammonia excretion in aquatic and terrestrial crabs.

    PubMed

    Weihrauch, Dirk; Morris, Steve; Towle, David W

    2004-12-01

    The excretory transport of toxic ammonia across epithelia is not fully understood. This review presents data combined with models of ammonia excretion derived from studies on decapod crabs, with a view to providing new impetus to investigation of this essential issue. The majority of crabs preserve ammonotely regardless of their habitat, which varies from extreme hypersaline to freshwater aquatic environments, and ranges from transient air exposure to obligate air breathing. Important components in the excretory process are the Na+/K+(NH4+)-ATPase and other membrane-bound transport proteins identified in many species, an exocytotic ammonia excretion mechanism thought to function in gills of aquatic crabs such as Carcinus maenas, and gaseous ammonia release found in terrestrial crabs, such as Geograpsus grayi and Ocypode quadrata. In addition, this review presents evidence for a crustacean Rhesus-like protein that shows high homology to the human Rhesus-like ammonia transporter both in its amino acid sequence and in its predicted secondary structure. PMID:15579545

  1. Effect of ions on the measurement of sulphuric acid in the CLOUD experiment at CERN

    NASA Astrophysics Data System (ADS)

    Rondo, L.; Kürten, A.; Ehrhart, S.; Schobesberger, S.; Franchin, A.; Junninen, H.; Petäjä, T.; Sipilä, M.; Worsnop, D. R.; Curtius, J.

    2014-07-01

    Ternary aerosol nucleation experiments were conducted in the CLOUD chamber at CERN in order to investigate the influence of ions on new particle formation. Neutral and ion-induced nucleation experiments, i.e., with and without the presence of ions, were carried out under precisely controlled conditions. The sulphuric acid concentration was measured with a Chemical Ionization Mass Spectrometer (CIMS) during the new particle formation experiments. The added ternary trace gases were ammonia (NH3), dimethylamine (DMA, C2H7N) or oxidised products of pinanediol (PD, C10H18O2). When pinanediol was introduced into the chamber, an increase in the mass spectrometric signal used to determine the sulphuric acid concentration (m/z 97, i.e., HSO4-) was observed due to ions from the CLOUD chamber. The enhancement was only observed during ion-induced nucleation measurements by using either galactic cosmic rays (GCR) or the proton synchrotron (PS) pion beam for the ion generation, respectively. The ion effect typically involved an increase in the apparent sulphuric acid concentration by a factor of ~2 to 3 and was qualitatively verified by the ion measurements by an Atmospheric Pressure interface-Time Of Flight (APi-TOF) mass spectrometer. By applying a high voltage (HV) clearing field inside the CLOUD chamber the ion effect on the CIMS measurement was completely eliminated since, under these conditions, small ions are swept from the chamber in about one second. In order to exclude the ion effect and to provide corrected sulphuric acid concentrations during the GCR and PS beam nucleation experiments, a parameterisation was derived that utilizes the trace gas concentrations and the UV light intensity as input parameters. Atmospheric sulphuric acid measurements with a CIMS showed an insignificant ion effect.

  2. Effect of ions on the measurement of sulfuric acid in the CLOUD experiment at CERN

    NASA Astrophysics Data System (ADS)

    Rondo, L.; Kürten, A.; Ehrhart, S.; Schobesberger, S.; Franchin, A.; Junninen, H.; Petäjä, T.; Sipilä, M.; Worsnop, D. R.; Curtius, J.

    2014-11-01

    Ternary aerosol nucleation experiments were conducted in the CLOUD chamber at CERN in order to investigate the influence of ions on new particle formation. Neutral and ion-induced nucleation experiments, i.e. without and with the presence of ions, respectively, were carried out under precisely controlled conditions. The sulfuric acid concentration was measured with a chemical ionisation mass spectrometer (CIMS) during the new particle formation experiments. The added ternary trace gases were ammonia (NH3), dimethylamine (DMA, C2H7N) or oxidised products of pinanediol (PD, C10H18O2). When pinanediol was introduced into the chamber, an increase in the mass spectrometric signal used to determine the sulfuric acid concentration (m/z 97, i.e. HSO4-) was observed due to ions from the CLOUD chamber. The enhancement was only observed during ion-induced nucleation measurements by using either galactic cosmic rays (GCRs) or the proton synchrotron (PS) pion beam for the ion generation, respectively. The ion effect typically involved an increase in the apparent sulfuric acid concentration by a factor of ~ 2 to 3 and was qualitatively verified by the ion measurements with an atmospheric-pressure interface-time of flight (APi-TOF) mass spectrometer. By applying a high-voltage (HV) clearing field inside the CLOUD chamber, the ion effect on the CIMS measurement was completely eliminated since, under these conditions, small ions are swept from the chamber in about 1 s. In order to exclude the ion effect and to provide corrected sulfuric acid concentrations during the GCR and PS beam nucleation experiments, a parameterisation was derived that utilises the trace gas concentrations and the UV light intensity as input parameters. Atmospheric sulfuric acid measurements with a CIMS showed an insignificant ion effect.

  3. Methylmalonic acid blood test

    MedlinePlus

    ... acid is a substance produced when proteins, called amino acids, in the body break down. The health care ... Cederbaum S, Berry GT. Inborn errors of carbohydrate, ammonia, amino acid, and organic acid metabolism. In: Gleason CA, Devaskar ...

  4. Fundamental and overtone vibrational spectroscopy, enthalpy of hydrogen bond formation and equilibrium constant determination of the methanol-dimethylamine complex.

    PubMed

    Du, Lin; Mackeprang, Kasper; Kjaergaard, Henrik G

    2013-07-01

    We have measured gas phase vibrational spectra of the bimolecular complex formed between methanol (MeOH) and dimethylamine (DMA) up to about 9800 cm(-1). In addition to the strong fundamental OH-stretching transition we have also detected the weak second overtone NH-stretching transition. The spectra of the complex are obtained by spectral subtraction of the monomer spectra from spectra recorded for the mixture. For comparison, we also measured the fundamental OH-stretching transition in the bimolecular complex between MeOH and trimethylamine (TMA). The enthalpies of hydrogen bond formation (ΔH) for the MeOH-DMA and MeOH-TMA complexes have been determined by measurements of the fundamental OH-stretching transition in the temperature range from 298 to 358 K. The enthalpy of formation is found to be -35.8 ± 3.9 and -38.2 ± 3.3 kJ mol(-1) for MeOH-DMA and MeOH-TMA, respectively, in the 298 to 358 K region. The equilibrium constant (Kp) for the formation of the MeOH-DMA complex has been determined from the measured and calculated transition intensities of the OH-stretching fundamental transition and the NH-stretching second overtone transition. The transition intensities were calculated using an anharmonic oscillator local mode model with dipole moment and potential energy curves calculated using explicitly correlated coupled cluster methods. The equilibrium constant for formation of the MeOH-DMA complex was determined to be 0.2 ± 0.1 atm(-1), corresponding to a ΔG value of about 4.0 kJ mol(-1).

  5. Insights on co-catalyst-promoted enamine formation between dimethylamine and propanal through ab initio and density functional theory study.

    PubMed

    Patil, Mahendra P; Sunoj, Raghavan B

    2007-10-26

    The mechanistic details on enamine formation between dimethylamine and propanal are unraveled using the ab initio and density functional theory methods. The addition of secondary amine to the electrophile and simultaneous proton transfer results in a carbinolamine intermediate, which subsequently undergoes dehydration to form enamine. The direct addition of amine as well as the dehydration of the resulting carbinolamine intermediate is predicted to possess fairly high activation barrier implying that a unimolecular process is unlikely to be responsible for enamine formation. Different models are therefore proposed which could explain the relative ease of enamine formation under neat condition as well as under the influence of methanol as the co-catalyst. The explicit inclusion of either the reagent or the co-catalyst is considered in the transition states as stabilizing agents. The participation of the reagent or the co-catalyst as a monofunctional ancillary species is found to stabilize the transition states relative to the unassisted or the direct addition/dehydration pathways. The reduction in enthalpy of activation is found to be much more dramatic when two co-catalysts participate in an active bifunctional mode in the rate-determining dehydration step. The transition structures exhibited characteristic features of a relay proton transfer mechanism. The free energy of activation associated with the two methanol-assisted pathway is found to be 16.7 kcal/mol lower than that of the unassisted pathway. The results are found to be in concurrence with the available reports on the rate acceleration by co-catalysts in the Michael reaction between enamine and methyl vinyl ketone under neat conditions.

  6. EFFECTS OF AMMONIA LOADING ON PORCELLIO SCABER: GLUTAMINE AND GLUTAMATE SYNTHESIS, AMMONIA EXCRETION AND TOXICITY

    PubMed

    Wright; Donnell; Reichert

    1994-03-01

    The effects of ammonia loading in the terrestrial isopod Porcellio scaber were studied by exposing animals to atmospheres of high PNH3. Isopods show a remarkable tolerance of elevated ambient PNH3, with an LD50 of 89 Pa for a 7-day exposure. However, haemolymph total ammonia concentrations generally remained below 5 mmol l-1 (PNH3=0.37 Pa) over the range of ambient ammonia levels used (6.6­165 Pa). Following a 7-day loading period, whole-animal glutamine (Gln) and glutamate (Glu) levels increased in direct proportion to ambient PNH3, reaching values of 35 µmol g-1 fresh mass for glutamine and 12 µmol g-1 fresh mass for glutamate in 99 Pa PNH3; these correspond to control levels of 7.5 µmol g-1 fresh mass and 5.9 µmol g-1 fresh mass, respectively. Following transfer to ammonia-free chambers, NH3 excretion rates were augmented five- to sixfold relative to non-loaded controls. Ammonia volatilization subsequently declined, approaching control levels after 8­9 days. Levels of Gln and Glu showed a concomitant decline to 13.7 µmol g-1 fresh mass and 9.2 µmol g-1 fresh mass, respectively. The results suggest that these amino acids function in ammonia sequestration and, hence, detoxification. Calculations indicate that mobilization of amino groups by deamination of accumulated Gln and Glu could explain 35 % of the increased ammonia production. Implications of NH3 volatilization for acid­base balance are discussed.

  7. Fate of ammonia in the atmosphere--a review for applicability to hazardous releases.

    PubMed

    Renard, Jean J; Calidonna, Sheryl E; Henley, Michael V

    2004-04-30

    The physical and chemical mechanisms responsible for the removal of ammonia from the atmosphere have been reviewed. Capture by atmospheric moisture (clouds, rain, fog), surface water (rivers, lakes, seas), and deposition on vegetation and soil constitute the main pathways for ammonia removal from the troposphere. Ammonia catalyzes the atmospheric oxidation of sulfur dioxide to sulfur trioxide and reacts rapidly with acidic components of the atmosphere (sulfuric, nitric, and hydrochloric acids). The ammonium salts formed are the main components of smog aerosols and thus affect the opacity of the atmosphere and the earth radiation budget. Slow oxidation of ammonia in the atmosphere plays only a minor role in its removal. The data obtained for ammonia reactions under normal atmospheric conditions are generally applicable to model chemical reactions occurring during massive release of ammonia in the atmosphere, provided the impact of high ammonia concentration on the mass transfer processes that control some of these reactions, are taken into account.

  8. Fate of ammonia in the atmosphere--a review for applicability to hazardous releases.

    PubMed

    Renard, Jean J; Calidonna, Sheryl E; Henley, Michael V

    2004-04-30

    The physical and chemical mechanisms responsible for the removal of ammonia from the atmosphere have been reviewed. Capture by atmospheric moisture (clouds, rain, fog), surface water (rivers, lakes, seas), and deposition on vegetation and soil constitute the main pathways for ammonia removal from the troposphere. Ammonia catalyzes the atmospheric oxidation of sulfur dioxide to sulfur trioxide and reacts rapidly with acidic components of the atmosphere (sulfuric, nitric, and hydrochloric acids). The ammonium salts formed are the main components of smog aerosols and thus affect the opacity of the atmosphere and the earth radiation budget. Slow oxidation of ammonia in the atmosphere plays only a minor role in its removal. The data obtained for ammonia reactions under normal atmospheric conditions are generally applicable to model chemical reactions occurring during massive release of ammonia in the atmosphere, provided the impact of high ammonia concentration on the mass transfer processes that control some of these reactions, are taken into account. PMID:15081162

  9. The Ammonia-Soda Process.

    ERIC Educational Resources Information Center

    Tingle, M.

    1979-01-01

    This article is a condensed version of a commentary written to accompany a set of slides which describes the ammonia-soda process used by the ammonia-soda plant at Northwich of the United Kingdom. (HM)

  10. Liberation of ammonia by cyanobacteria

    SciTech Connect

    Newton, J.W.

    1986-04-01

    Photoheterotrophic nitrogen-fixing cyanobacteria release ammonia when treated with methionine sulfoximine (MSX) to inhibit nitrogen incorporation into protein. This released ammonia can be derived from recently fixed nitrogen (nitrogen atmosphere) or endogenous reserves (argon atmosphere). Anaerobic ammonia release requires light and is stimulated by the photosystem II herbicides DCMU and Atrazine, regardless of the source of ammonia. As much as one quarter of the total cellular nitrogen can be released as ammonia by cyanbacteria treated with MSX and DCMU under argon in light. Chromatography of cell extracts indicates that virtually all cellular proteins are degraded. DCMU and Atrazine, at very low concentration, inhibit sustained uptake of the ammonia analog /sup 14/C methylamine. These data indicate that the herbicides interrupt ammonia uptake and retention by the cells, and support a role for photosystem II in ammonia metabolism.

  11. The Chemistry of Liquid Ammonia.

    ERIC Educational Resources Information Center

    Lagowski, J. J.

    1978-01-01

    The solvent and chemical properties of liquid ammonia are presented. In a certain sense, ammonia is a more versatile solvent than is water because of its ability to solubilize, without reaction, highly negative or reducing species. (Author/BB)

  12. Kinetics and thermochemistry of hydrolysis mechanism of a novel anticancer agent trans-[PtCl2(dimethylamine)(isopropylamine)]: A DFT study

    NASA Astrophysics Data System (ADS)

    Hussain, Iftikar; Gour, N. K.; Deka, Ramesh Ch.

    2016-05-01

    Theoretical investigation has been made on the hydrolysis mechanism of a novel transplatin anticancer agent trans-[PtCl2(dimethylamine)(isopropylamine)] in gas as well as aqueous phases using DFT method. The transition state geometries along with other stationary points on potential energy surface are optimized and characterized. The calculated activation barrier and the predicted relative free energies for the two successive steps are in good agreement with the experimental data reported in the literature. The rate constants are calculated using Eyring equation and results show that the second step is the rate-limiting process having higher activation energy compared to that of the first step.

  13. Eudragit E100 as a drug carrier: the remarkable affinity of phosphate ester for dimethylamine.

    PubMed

    Guzmán, M L; Manzo, R H; Olivera, M E

    2012-09-01

    Therapeutic agents containing phosphate groups in their molecules have increasing therapeutic impact. The object of this study was to characterize the cationic polyelectrolyte Eudragit E100 (EuE100) as a carrier for drugs containing phosphate groups, using dexamethasone phosphate (DP) as a model. A series of EuE100-DP complexes was obtained by acid-base reaction in which DP neutralized 12.5-75% of the basic groups of EuE100. The solids obtained after solvent evaporation revealed by spectroscopic characterization the complete reaction between the components through the ionic interaction between the amine groups of EuE100 and the phosphate groups of DP. The reversibility of the counterion condensation, evaluated through the proton-withdrawing effect produced by the ionic exchange generated by titration with NaCl, showed a remarkable high affinity between EuE100 and DP. In line, drug delivery in bicompartimental Franz cells toward water as receptor medium was very slow (2% in 6 h). However, it was increased as water was replaced by NaCl solution, which upon diffusion generates ionic exchange. A sustained release of DP with noticeable zero order kinetics accounted for a remarkable high affinity, mainly due to the electrostatic attraction. The release rate remains constant regardless of the saline concentration of the media. Besides, the delivery control is maintained even in gastric simulated fluid, a property not informed previously for EuE100 complexes. PMID:22808998

  14. Ammonia tank failure

    SciTech Connect

    Sweat, M.E.

    1983-04-01

    An ammonia tank failure at Hawkeye Chemical of Clinton, Iowa is discussed. The tank was a double-wall, 27,000 metric-ton tank built in 1968 and commissioned in December 1969. The paper presented covers the cause of the failure, repair, and procedural changes made to prevent recurrence of the failure. (JMT)

  15. The role of the small intestine in ammonia production after gastric blood administration.

    PubMed Central

    Sugarbaker, S P; Revhaug, A; Wilmore, D W

    1987-01-01

    It is commonly believed that the digestion of intraluminal blood by colonic bacteria is the primary cause of increased ammonia production after upper gastrointestinal hemorrhage. To evaluate the role of the small intestine in ammonia production, blood, amino acids, or water (5 mL/kg) was administered as a meal or enema to awake dogs with chronic indwelling catheters. After blood meals, intestinal ammonia production increased rapidly to peak at 60 minutes and returned to basal levels. This response was mimicked by the gastric administration of ammoniagenic amino acids. No change in ammonia production occurred with water administration. In contrast, colonic blood administration resulted in a gradual rise in ammonia production, and peaked at 150 minutes. Amino acid enemas resulted in a similar but somewhat more rapid response. No change occurred with water enemas. After gut decontamination, ammonia production did not increase after blood enemas. However, the rapid increase in ammonia production persisted after blood meals. It is concluded that both the small bowel and colon participate in the augmented ammonia production that occurs after upper gastrointestinal hemorrhage. Gut decontamination reduces ammonia production by altering the colonic microflora, but is not specific therapy directed towards amino acid metabolism by the enterocytes of the small bowel and thus, does not alter the ammonia produced by the small intestine. PMID:3496861

  16. An intercomparison of five ammonia measurement techniques

    NASA Technical Reports Server (NTRS)

    Williams, E. J.; Sandholm, S. T.; Bradshaw, J. D.; Schendel, J. S.; Langford, A. O.; Quinn, P. K.; Lebel, P. J.; Vay, S. A.; Roberts, P. D.; Norton, R. B.

    1992-01-01

    Results obtained from five techniques for measuring gas-phase ammonia at low concentration in the atmosphere are compared. These methods are: (1) a photofragmentation/laser-induced fluorescence (PF/LIF) instrument; (2) a molybdenum oxide annular denuder sampling/chemiluminescence detection technique; (3) a tungsten oxide denuder sampling/chemiluminescence detection system; (4) a citric-acid-coated denuder sampling/ion chromatographic analysis (CAD/IC) method; and (5) an oxalic-acid-coated filter pack sampling/colorimetric analysis method. It was found that two of the techniques, the PF/LIF and the CAD/IC methods, measured approximately 90 percent of the calculated ammonia added in the spiking tests and agreed very well with each other in the ambient measurements.

  17. Autotrophic ammonia oxidation at low pH through urea hydrolysis.

    PubMed

    Burton, S A; Prosser, J I

    2001-07-01

    Ammonia oxidation in laboratory liquid batch cultures of autotrophic ammonia oxidizers rarely occurs at pH values less than 7, due to ionization of ammonia and the requirement for ammonium transport rather than diffusion of ammonia. Nevertheless, there is strong evidence for autotrophic nitrification in acid soils, which may be carried out by ammonia oxidizers capable of using urea as a source of ammonia. To determine the mechanism of urea-linked ammonia oxidation, a ureolytic autotrophic ammonia oxidizer, Nitrosospira sp. strain NPAV, was grown in liquid batch culture at a range of pH values with either ammonium or urea as the sole nitrogen source. Growth and nitrite production from ammonium did not occur at pH values below 7. Growth on urea occurred at pH values in the range 4 to 7.5 but ceased when urea hydrolysis was complete, even though ammonia, released during urea hydrolysis, remained in the medium. The results support a mechanism whereby urea enters the cells by diffusion and intracellular urea hydrolysis and ammonia oxidation occur independently of extracellular pH in the range 4 to 7.5. A proportion of the ammonia produced during this process diffuses from the cell and is not subsequently available for growth if the extracellular pH is less than 7. Ureolysis therefore provides a mechanism for nitrification in acid soils, but a proportion of the ammonium produced is likely to be released from the cell and may be used by other soil organisms.

  18. Proximal tubule-specific glutamine synthetase deletion alters basal and acidosis-stimulated ammonia metabolism.

    PubMed

    Lee, Hyun-Wook; Osis, Gunars; Handlogten, Mary E; Lamers, Wouter H; Chaudhry, Farrukh A; Verlander, Jill W; Weiner, I David

    2016-06-01

    Glutamine synthetase (GS) catalyzes the recycling of NH4 (+) with glutamate to form glutamine. GS is highly expressed in the renal proximal tubule (PT), suggesting ammonia recycling via GS could decrease net ammoniagenesis and thereby limit ammonia available for net acid excretion. The purpose of the present study was to determine the role of PT GS in ammonia metabolism under basal conditions and during metabolic acidosis. We generated mice with PT-specific GS deletion (PT-GS-KO) using Cre-loxP techniques. Under basal conditions, PT-GS-KO increased urinary ammonia excretion significantly. Increased ammonia excretion occurred despite decreased expression of key proteins involved in renal ammonia generation. After the induction of metabolic acidosis, the ability to increase ammonia excretion was impaired significantly by PT-GS-KO. The blunted increase in ammonia excretion occurred despite greater expression of multiple components of ammonia generation, including SN1 (Slc38a3), phosphate-dependent glutaminase, phosphoenolpyruvate carboxykinase, and Na(+)-coupled electrogenic bicarbonate cotransporter. We conclude that 1) GS-mediated ammonia recycling in the PT contributes to both basal and acidosis-stimulated ammonia metabolism and 2) adaptive changes in other proteins involved in ammonia metabolism occur in response to PT-GS-KO and cause an underestimation of the role of PT GS expression.

  19. Adsorption of Ammonia on Regenerable Carbon Sorbents

    NASA Technical Reports Server (NTRS)

    Wójtowicz, Marek A.; Cosgrove, Jesph E.; Serio, Michael A..; Wilburn, Monique

    2015-01-01

    Results are presented on the development of reversible sorbents for the combined carbon dioxide, moisture, and trace-contaminant (TC) removal for use in Extravehicular Activities (EVAs), and more specifically in the Primary Life Support System (PLSS). The currently available life support systems use separate units for carbon dioxide, trace contaminants, and moisture control, and the long-term objective is to replace the above three modules with a single one. Data on sorption and desorption of ammonia, which is a major TC of concern, are presented in this paper. The current TC-control technology involves the use of a packed bed of acid-impregnated granular charcoal, which is non-regenerable, and the carbon-based sorbent under development in this project can be regenerated by exposure to vacuum at room temperature. In this study, several carbon sorbents were fabricated and tested for ammonia sorption. Ammonia-sorption capacity was related to carbon pore structure characteristics, and the temperature of oxidative carbon-surface treatment was optimized for enhanced ammonia-sorption performance.

  20. Ammonia biofiltration and community analysis of ammonia-oxidizing bacteria in biofilters.

    PubMed

    Jun, Yin; Wenfeng, Xu

    2009-09-01

    Biological removal of ammonia was investigated using compost and sludge as packing materials in laboratory-scale biofilters. The aim of this study is to characterize the composition of ammonia-oxidizing bacteria (AOB) in two biofilters designed to remove ammonia. Experimental tests and measurements included analysis of removal efficiency and metabolic products. The inlet concentration of ammonia applied was 20-100 mg m(-3). Removal efficiencies of BFC and BFS were in the range of 97-99% and 95-99%, respectively. Periodic analysis of the biofilter packing materials showed ammonia was removed from air stream by nitrification and by the improved absorption of NH(3) in the resultant acidity. Nitrate was the dominant product of NH(3) transformation. Changes in the composition of AOB were examined by using nested PCR, denaturing gradient gel electrophoresis (DGGE) and sequencing of DGGE bands. DGGE analysis of biofilter samples revealed that shifts in the community structure of AOB were observed in the experiment; however, the idle phase did not cause the structural shift of AOB. Phylogenetic analysis revealed the population of AOB showed Nitrosospira sp. remains the predominant population in BFC, while Nitrosomonas sp. is the predominant population in BFS.

  1. Integrated optic ammonia sensor

    NASA Astrophysics Data System (ADS)

    Klein, Rainer; Voges, Edgar I.

    1993-05-01

    Most of the disadvantages that exist with electrochemical devices (e.g., short lifetimes, difficult to miniaturize, need of reference electrodes) can be avoided by using optical sensors. Smock et al. describe a device incorporating a ninhydrin coated fused silica rod that could detect ammonia vapor at concentrations below 100 ppb, however, the reaction is irreversible. Guiliani et al. describe a reversible sensor using a dye coated capillary tube. The dye utilized is oxazine perchlorate, a laser dye. They report that the presence of water vapor is an important factor in the detection of ammonia, and the concentration of water vapor must be controlled. Optical sensors built-up in integrated-optic technique with planar waveguide configurations allow the construction of optical sensor systems for a parallel detection of several chemical species, provide the generation of reference signals, and facilitate the problem of cross-sensitivities. Here, we report on integrated-optic sensors for ammonia detection with a sensitivity in the ppb-range. The reaction is reversible, and the response is independent of the water vapor concentration in the test gas.

  2. Atmospheric dispersion of ammonia: an ammonia fog model

    SciTech Connect

    Kansa, E.J.; Rodean, H.C.; Chan, S.T.; Ermak, D.L.

    1983-01-01

    A simplification to the two-phase ammonia vapor-droplet fog problem has been implemented to study the dispersion of a spill of 40 tons of ammonia. We have circumvented the necessity of adding the partial differential equations for mass, momentum, and energy for the ammonia in the liquid phase by certain assumptions. It is assumed that the ammonia fog behaves as an ideal gas including the droplets. A temperature-dependent molecular weight was introduced to simulate the transition from a vapor-droplet cloud to a pure vapor cloud of ammonia. Likewise, the vaporization of ammonia was spread out over a temperature range. Mass, momentum, energy, and total ammonia is conserved rigorously. The observed features of the ammonia spill simulation have pointed out phenomena that could not be predicted in simpler calculations. Perhaps the most obvious feature is the cloud bifurcation due to the strength of the gravity current relative to the ambient wind. The gravity spreading of the denser ammonia fog significantly perturbs the unidirectional windfield in the vicinity of the spill, setting up complex eddy patterns in the cloud which are enhanced by ground heating and warm dry air entrainment. The lower concentrations appear to lift off by a buoyancy-induced flow. The ammonia cloud, rather than being cigar shaped as assumed in simpler models, ranges from pancake shaped to pear shaped, depending upon the ambient windfield. The fact that the ammonia cloud remains cold, very low, and wide is in qualitative agreement with some of the large-scale ammonia spill accidents. 14 figures.

  3. Effect of ammonia stress on nitrogen metabolism of Ceratophyllum demersum.

    PubMed

    Gao, Jingqing; Li, Linshuai; Hu, Zhiyuan; Yue, Hui; Zhang, Ruiqin; Xiong, Zhiting

    2016-01-01

    The objective of the present study was to determine the effect of total ammonia N concentration and pH on N metabolism of Ceratophyllum demersum and to evaluate stress as a result of inorganic N enrichment in the water column on submerged macrophytes. Carefully controlled pH values distinguished between the effects of un-ionized NH3 and ionized NH4(+). The results showed that the most obvious consequence of ammonia addition was an overall increase in ammonia content and decrease in nitrate content in all tissues of fertilized plants. The activities of nitrate reductase and glutamine synthetase were inhibited by long-term ammonia addition. At the same time, ammonia addition significantly decreased soluble protein content and increased free amino acid content in all treatments. Another clear effect of ammonia addition was a decrease in carbon reserves. Therefore, the authors concluded that increased ammonia availability could affect plant survival and lead to a decline in C. demersum proliferation through a decrease in their carbon reserves. This interaction between N and C metabolism helps to explain changes in benthic vegetation as a result of steadily increasing coastal water eutrophication.

  4. Effect of ammonia stress on nitrogen metabolism of Ceratophyllum demersum.

    PubMed

    Gao, Jingqing; Li, Linshuai; Hu, Zhiyuan; Yue, Hui; Zhang, Ruiqin; Xiong, Zhiting

    2016-01-01

    The objective of the present study was to determine the effect of total ammonia N concentration and pH on N metabolism of Ceratophyllum demersum and to evaluate stress as a result of inorganic N enrichment in the water column on submerged macrophytes. Carefully controlled pH values distinguished between the effects of un-ionized NH3 and ionized NH4(+). The results showed that the most obvious consequence of ammonia addition was an overall increase in ammonia content and decrease in nitrate content in all tissues of fertilized plants. The activities of nitrate reductase and glutamine synthetase were inhibited by long-term ammonia addition. At the same time, ammonia addition significantly decreased soluble protein content and increased free amino acid content in all treatments. Another clear effect of ammonia addition was a decrease in carbon reserves. Therefore, the authors concluded that increased ammonia availability could affect plant survival and lead to a decline in C. demersum proliferation through a decrease in their carbon reserves. This interaction between N and C metabolism helps to explain changes in benthic vegetation as a result of steadily increasing coastal water eutrophication. PMID:26222052

  5. Fungal and Plant Phenylalanine Ammonia-lyase

    PubMed Central

    Hyun, Min Woo; Yun, Yeo Hong; Kim, Jun Young

    2011-01-01

    L-Phenylalanine is one of the essential amino acids that cannot be synthesized in mammals in adequate amounts to meet the requirements for protein synthesis. Fungi and plants are able to synthesize phenylalanine via the shikimic acid pathway. L-Phenylalanine, derived from the shikimic acid pathway, is used directly for protein synthesis in plants or metabolized through the phenylpropanoid pathway. This phenylpropanoid metabolism leads to the biosynthesis of a wide array of phenylpropanoid secondary products. The first step in this metabolic sequence involves the action of phenylalanine ammonia-lyase (PAL). The discovery of PAL enzyme in fungi and the detection of 14CO2 production from 14C-ring-labeled phenylalanine and cinnamic acid demonstrated that certain fungi can degrade phenylalanine by a pathway involving an initial deamination to cinnamic acid, as happens in plants. In this review, we provide background information on PAL and a recent update on the presence of PAL genes in fungi. PMID:22783113

  6. Hydrogen bonding in the benzene-ammonia dimer

    NASA Technical Reports Server (NTRS)

    Rodham, David A.; Suzuki, Sakae; Suenram, Richard D.; Lovas, Frank J.; Dasgupta, Siddharth; Goddard, William A., III; Blake, Geoffrey A.

    1993-01-01

    High-resolution optical and microwave spectra of the gas-phase benzene-ammonia dimer were obtained, showing that the ammonia molecule resides above the benzene plane and undergoes free, or nearly free, internal rotation. To estimate the binding energy (De) and other global properties of the intermolecular potential, theoretical calculations were performed for the benzene-ammonia dimer, using the Gaussian 92 (Fritsch, 1992) program at the MP2/6-31G** level. The predicted De was found to be at the lowest end of the range commonly accepted for hydrogen bonding and considerably below that of C6H6-H2O, consistent with the gas-phase acidities of ammonia and water. The observed geometry greatly resembles the amino-aromatic interaction found naturally in proteins.

  7. Germanium(II) hydride mediated reduction of carbon dioxide to formic acid and methanol with ammonia borane as the hydrogen source.

    PubMed

    Jana, Anukul; Tavčar, Gašper; Roesky, Herbert W; John, Michael

    2010-10-28

    LGeOC(O)H (3) (L = CH{(CMe)(2,6-iPr(2)C(6)H(3)N)}(2)), from the straightforward conversion of LGeH (2) with CO(2), reacts with LiH(2)NBH(3) giving 2 and LiOC(O)H (4), while the corresponding reaction of 3 with H(3)NBH(3) after aqueous workup releases 2 and CH(3)OH (5). This opens the possibility to use hydride 2 as a mediator in the reduction of carbon dioxide to formic acid and methanol. PMID:20830405

  8. Germanium(II) hydride mediated reduction of carbon dioxide to formic acid and methanol with ammonia borane as the hydrogen source.

    PubMed

    Jana, Anukul; Tavčar, Gašper; Roesky, Herbert W; John, Michael

    2010-10-28

    LGeOC(O)H (3) (L = CH{(CMe)(2,6-iPr(2)C(6)H(3)N)}(2)), from the straightforward conversion of LGeH (2) with CO(2), reacts with LiH(2)NBH(3) giving 2 and LiOC(O)H (4), while the corresponding reaction of 3 with H(3)NBH(3) after aqueous workup releases 2 and CH(3)OH (5). This opens the possibility to use hydride 2 as a mediator in the reduction of carbon dioxide to formic acid and methanol.

  9. Ammonia in breath and emitted from skin.

    PubMed

    Schmidt, F M; Vaittinen, O; Metsälä, M; Lehto, M; Forsblom, C; Groop, P-H; Halonen, L

    2013-03-01

    Ammonia concentrations in exhaled breath (eNH3) and skin gas of 20 healthy subjects were measured on-line with a commercial cavity ring-down spectrometer and compared to saliva pH and plasma ammonium ion (NH(+)4), urea and creatinine concentrations. Special attention was given to mouth, nose and skin sampling procedures and the accurate quantification of ammonia in humid gas samples. The obtained median concentrations were 688 parts per billion by volume (ppbv) for mouth-eNH3, 34 ppbv for nose-eNH3, and 21 ppbv for both mouth- and nose-eNH3 after an acidic mouth wash (MW). The median ammonia emission rate from the lower forearm was 0.3 ng cm(-2) min(-1). Statistically significant (p < 0.05) correlations between the breath, skin and plasma ammonia/ammonium concentrations were not found. However, mouth-eNH3 strongly (p < 0.001) correlated with saliva pH. This dependence was also observed in detailed measurements of the diurnal variation and the response of eNH3 to the acidic MW. It is concluded that eNH3 as such does not reflect plasma but saliva and airway mucus NH(+)4 concentrations and is affected by saliva and airway mucus pH. After normalization with saliva pH using the Henderson-Hasselbalch equation, mouth-eNH3 correlated with plasma NH(+)4, which points to saliva and plasma NH(+)4 being linked via hydrolysis of salivary urea.

  10. Sheldon Shore, Small Boranes, and Ammonia

    NASA Astrophysics Data System (ADS)

    Parry, Robert W.

    1997-05-01

    Although trimethylamine [(CH3)3N] and ammonia [H3N] are both recognized as classic Lewis bases, their reactions with the classic Lewis acid borane [BH3 from diborane] was very different. Trimethylamine gave the expected trimethylamine borane [(CH3)3NBH3] while ammonia gave a product called "the diammoniate of diborane." Its structure was shown to be [H2B(NH3)2]+[BH4]- in the late nineteen fifties. The Compound [H2B(NH3)2]+[BH4]- can be viewed as a classic coordination compound in which four-coordinate boron +3 ions are coordinated to the hydride ion and the ammonia molecule as ligands. It is noted that CoCl2 reacts with (CH3)3N and with NH3 in different ways. The "anomaly" is in the bases, not the borane acid. The paper discusses the early studies on "the diammoniate of diborane" and emphasizes how continuing work done by Sheldon Shore at Ohio State University extended the work on the boranes and answered here-to-fore vexing structural problems on intermediates in the borane and borane-ammonia system. His work made major contributions to synthesis. He worked out techniques to prepare significant quantities of pure [H2B(NH3)2][BH4] and of pure H3NBH3. He also prepared the fascinating, theoretically anticipated compounds K2BH3 and K2B2H6. The story, as told, shows how a brilliant, imaginative, and thoughtful person, using superb experimental techniques, has been able to develop a difficult experimental system from "black art" to sound science. Note: This article was prepared from a talk given by the author at a Symposium (8/23/95) honoring Sheldon G. Shore on his sixty-fifth birthday. Dr. Shore is the Charles H. Kimberly Professor of Chemistry at Ohio State University.

  11. Nuclear spatial delocalization silences electron density oscillations in 2-phenyl-ethyl-amine (PEA) and 2-phenylethyl-N,N-dimethylamine (PENNA) cations.

    PubMed

    Jenkins, Andrew J; Vacher, Morgane; Bearpark, Michael J; Robb, Michael A

    2016-03-14

    We simulate electron dynamics following ionization in 2-phenyl-ethyl-amine and 2-phenylethyl-N,N-dimethylamine as examples of systems where 3 coupled cationic states are involved. We study two nuclear effects on electron dynamics: (i) coupled electron-nuclear motion and (ii) nuclear spatial delocalization as a result of the zero-point energy in the neutral molecule. Within the Ehrenfest approximation, our calculations show that the coherent electron dynamics in these molecules is not lost as a result of coupled electron-nuclear motion. In contrast, as a result of nuclear spatial delocalization, dephasing of the oscillations occurs on a time scale of only a few fs, long before any significant nuclear motion can occur. The results have been rationalized using a semi-quantitative model based upon the gradients of the potential energy surfaces.

  12. Nuclear spatial delocalization silences electron density oscillations in 2-phenyl-ethyl-amine (PEA) and 2-phenylethyl-N,N-dimethylamine (PENNA) cations

    NASA Astrophysics Data System (ADS)

    Jenkins, Andrew J.; Vacher, Morgane; Bearpark, Michael J.; Robb, Michael A.

    2016-03-01

    We simulate electron dynamics following ionization in 2-phenyl-ethyl-amine and 2-phenylethyl-N,N-dimethylamine as examples of systems where 3 coupled cationic states are involved. We study two nuclear effects on electron dynamics: (i) coupled electron-nuclear motion and (ii) nuclear spatial delocalization as a result of the zero-point energy in the neutral molecule. Within the Ehrenfest approximation, our calculations show that the coherent electron dynamics in these molecules is not lost as a result of coupled electron-nuclear motion. In contrast, as a result of nuclear spatial delocalization, dephasing of the oscillations occurs on a time scale of only a few fs, long before any significant nuclear motion can occur. The results have been rationalized using a semi-quantitative model based upon the gradients of the potential energy surfaces.

  13. Simultaneous and Real-time Measurement of Gaseous Ammonia and Particulate Ammonium

    NASA Astrophysics Data System (ADS)

    Kang, E.; Lee, J. H.

    2001-05-01

    Gaseous ammonia reacts with acidic gaseous species to neutralize atmospheric acidity and forms ammonium salts. In this neutralization reaction, ammonia is converted to ammonium ion in the particles. It plays an important role as CCN (cloud condensation nuclei) in the cloud formation. Moreover it plays a role on the cooling effect resulting from the reflection of solar radiation back to the space. Therefore, an improved simultaneous and real-time measurement technique for gaseous ammonia/particulate ammonium is needed to study the formation mechanism of CCN. Dual channel system for simultaneous and ream-time measurement of gaseous ammonia/particulate ammonium is described. In the 1st channel both gaseous ammonia/particulate ammonium is collected through a glass coil sampling system without citric acid coated denuder. In the 2nd channel gaseous ammonia is removed from the citric acid coated denuder and only particulate ammonium is collected through a glass coil sampling system. Using continuous flow injection system, collected ammonia (ammonium) reacts with sodium sulfite and o-phthaldialdehyde producing fluorescent product, which is detected by the fluorescence detector. The 1st channel signal represents the sum of gaseous ammonia and particulate ammonium, and the 2nd channel signal with the citric acid coated denuder represents only particulate ammonium. The difference in signal between two channels represents gaseous ammonia. This system shows each signal every second, and the baseline is recorded every 3 or 4 hours. Collection efficiency for gaseous ammonia was determined using consecutive two glass coil samplers. For the 2nd channel, collection efficiency of particulate ammonium is tested adapting consecutive two coil samplers. Gaseous ammonia and particulate ammonium were measured in Kwangju, South Korea at real time by using improved dual channel measurement system, and the detailed results and discussion will be presented in the presentation.

  14. Micelle Formation in Liquid Ammonia.

    PubMed

    Griffin, Joseph M; Atherton, John H; Page, Michael I

    2015-07-17

    Perfluorinated long chain alkyl amides aggregate in liquid ammonia with increasing concentration which reflects micelle-type formation based on changes in (19)F NMR chemical shifts. The critical micelle concentrations (cmc) decrease with increasing chain length and give Kleven parameters A = 0.18 and B = 0.19. The micelles catalyze the ammonolysis of esters in liquid ammonia. The corresponding perfluorinated long chain alkyl carboxylates form ion pairs in liquid ammonia, but the equilibrium dissociation constants indicate favorable interactions between the chains in addition to the electrostatic forces. These perfluorinated carboxylates form micelles in aqueous solution, and their cmc's generate a Kleven B-value = 0.52 compared with 0.30 for the analogous alkyl carboxylates. The differences in hydrophobicity of CH2 and CF2 units in water and liquid ammonia are discussed, as is the possible relevance to life forms in liquid ammonia.

  15. Interorgan ammonia metabolism in health and disease: a surgeon's view.

    PubMed

    Souba, W W

    1987-01-01

    Ammonia is a toxic molecule that is the principal by-product of amino acid metabolism. Although the transport of ammonia in a nontoxic form protects the brain against high circulating levels, the interorgan transport of this molecule and the orchestration between tissues that has evolved is related primarily to the fact that the nitrogen molecule is an essential molecule for the maintenance of the body's nutrition economy and overall metabolic homeostasis. Efficient handling and disposal of ammonia requires a cooperative effort between tissues in order to maintain nitrogen homeostasis. The liver is the central organ of ammonia metabolism, but other organs also play a key role in the interorgan exchange of this molecule. Alterations in ammonia metabolism occur during critical illness. These changes are adaptive and are designed to maintain metabolic homeostasis. Interorgan cooperation in ammonia metabolism is necessary to insure the proper integration of the metabolic processes which contribute to and are essential for survival during critical illness. An understanding of these processes improves our knowledge of metabolic regulation and will lead to a rational approach to the nutritional and metabolic support provided to critically ill patients. PMID:3323556

  16. Mechanism of ammonia excretion in the freshwater leech Nephelopsis obscura: characterization of a primitive Rh protein and effects of high environmental ammonia.

    PubMed

    Quijada-Rodriguez, Alex R; Treberg, Jason R; Weihrauch, Dirk

    2015-09-15

    Remarkably little is known about nitrogenous excretion in freshwater invertebrates. In the current study, the nitrogen excretion mechanism in the carnivorous ribbon leech, Nephelopsis obscura, was investigated. Excretion experiments showed that the ribbon leech is ammonotelic, excreting 166.0 ± 8.6 nmol·grams fresh weight (gFW)(-1)·h(-1) ammonia and 14.7 ± 1.9 nmol·gFW(-1)·h(-1) urea. Exposure to high and low pH hampered and enhanced, respectively, ammonia excretion rates, indicating an acid-linked ammonia trapping mechanism across the skin epithelia. Accordingly, compared with body tissues, the skin exhibited elevated mRNA expression levels of a newly identified Rhesus protein and at least in tendency the Na(+)/K(+)-ATPase. Pharmacological experiments and enzyme assays suggested an ammonia excretion mechanism that involves the V-ATPase, Na(+)/K(+)-ATPase, and carbonic anhydrase, but not necessarily a functional microtubule system. Most importantly, functional expression studies of the identified Rh protein cloned from leech skin tissue revealed an ammonia transport capability of this protein when expressed in yeast. The leech Rh-ammonia transporter (NoRhp) is a member of the primitive Rh protein family, which is a sister group to the common ancestor of vertebrate ammonia-transporting Rh proteins. Exposure to high environmental ammonia (HEA) caused a new adjustment of body ammonia, accompanied with a decrease in NoRhp and Na(+)/K(+)-ATPase mRNA levels, but unaltered ammonia excretion rates. To our knowledge, this is only the second comprehensive study regarding the ammonia excretion mechanisms in a freshwater invertebrate, but our results show that basic processes of ammonia excretion appear to also be comparable to those found in freshwater fish, suggesting an early evolution of ionoregulatory mechanisms in freshwater organisms.

  17. Mechanism of ammonia excretion in the freshwater leech Nephelopsis obscura: characterization of a primitive Rh protein and effects of high environmental ammonia

    PubMed Central

    Quijada-Rodriguez, Alex R.; Treberg, Jason R.

    2015-01-01

    Remarkably little is known about nitrogenous excretion in freshwater invertebrates. In the current study, the nitrogen excretion mechanism in the carnivorous ribbon leech, Nephelopsis obscura, was investigated. Excretion experiments showed that the ribbon leech is ammonotelic, excreting 166.0 ± 8.6 nmol·grams fresh weight (gFW)−1·h−1 ammonia and 14.7 ± 1.9 nmol·gFW−1·h−1 urea. Exposure to high and low pH hampered and enhanced, respectively, ammonia excretion rates, indicating an acid-linked ammonia trapping mechanism across the skin epithelia. Accordingly, compared with body tissues, the skin exhibited elevated mRNA expression levels of a newly identified Rhesus protein and at least in tendency the Na+/K+-ATPase. Pharmacological experiments and enzyme assays suggested an ammonia excretion mechanism that involves the V-ATPase, Na+/K+-ATPase, and carbonic anhydrase, but not necessarily a functional microtubule system. Most importantly, functional expression studies of the identified Rh protein cloned from leech skin tissue revealed an ammonia transport capability of this protein when expressed in yeast. The leech Rh-ammonia transporter (NoRhp) is a member of the primitive Rh protein family, which is a sister group to the common ancestor of vertebrate ammonia-transporting Rh proteins. Exposure to high environmental ammonia (HEA) caused a new adjustment of body ammonia, accompanied with a decrease in NoRhp and Na+/K+-ATPase mRNA levels, but unaltered ammonia excretion rates. To our knowledge, this is only the second comprehensive study regarding the ammonia excretion mechanisms in a freshwater invertebrate, but our results show that basic processes of ammonia excretion appear to also be comparable to those found in freshwater fish, suggesting an early evolution of ionoregulatory mechanisms in freshwater organisms. PMID:26180186

  18. Mechanism of ammonia excretion in the freshwater leech Nephelopsis obscura: characterization of a primitive Rh protein and effects of high environmental ammonia.

    PubMed

    Quijada-Rodriguez, Alex R; Treberg, Jason R; Weihrauch, Dirk

    2015-09-15

    Remarkably little is known about nitrogenous excretion in freshwater invertebrates. In the current study, the nitrogen excretion mechanism in the carnivorous ribbon leech, Nephelopsis obscura, was investigated. Excretion experiments showed that the ribbon leech is ammonotelic, excreting 166.0 ± 8.6 nmol·grams fresh weight (gFW)(-1)·h(-1) ammonia and 14.7 ± 1.9 nmol·gFW(-1)·h(-1) urea. Exposure to high and low pH hampered and enhanced, respectively, ammonia excretion rates, indicating an acid-linked ammonia trapping mechanism across the skin epithelia. Accordingly, compared with body tissues, the skin exhibited elevated mRNA expression levels of a newly identified Rhesus protein and at least in tendency the Na(+)/K(+)-ATPase. Pharmacological experiments and enzyme assays suggested an ammonia excretion mechanism that involves the V-ATPase, Na(+)/K(+)-ATPase, and carbonic anhydrase, but not necessarily a functional microtubule system. Most importantly, functional expression studies of the identified Rh protein cloned from leech skin tissue revealed an ammonia transport capability of this protein when expressed in yeast. The leech Rh-ammonia transporter (NoRhp) is a member of the primitive Rh protein family, which is a sister group to the common ancestor of vertebrate ammonia-transporting Rh proteins. Exposure to high environmental ammonia (HEA) caused a new adjustment of body ammonia, accompanied with a decrease in NoRhp and Na(+)/K(+)-ATPase mRNA levels, but unaltered ammonia excretion rates. To our knowledge, this is only the second comprehensive study regarding the ammonia excretion mechanisms in a freshwater invertebrate, but our results show that basic processes of ammonia excretion appear to also be comparable to those found in freshwater fish, suggesting an early evolution of ionoregulatory mechanisms in freshwater organisms. PMID:26180186

  19. Copper catalysed azide-alkyne cycloaddition (CuAAC) in liquid ammonia.

    PubMed

    Ji, Pengju; Atherton, John H; Page, Michael I

    2012-10-21

    Copper(I) catalysed azide-alkyne cycloaddition reactions (CuAAC) occur smoothly in liquid ammonia (LNH(3)) at room temperature to give exclusively 1,4-substituted 1,2,3-triazoles with excellent yields (up to 99%). The CuAAC reactions in liquid ammonia require relatively small amounts of copper(I) catalyst (0.5 mole%) compared with that in conventional solvents. The product can be obtained conveniently by simply evaporation of ammonia, indicating its potential application in industry. The rate of the CuAAC reaction in liquid ammonia shows a second order dependence on the copper(I) concentration and the reaction occurs only with terminal alkynes. Deuterium exchange experiments with phenyl acetylene-d(1) show that the acidity of the alkyne is increased at least 1000-fold with catalytic amounts of copper(I) in liquid ammonia. The mechanism of the CuAAC reaction in liquid ammonia is discussed. PMID:22930181

  20. Tolerance response to in situ ammonia stress in a pilot-scale anaerobic digestion reactor for alleviating ammonia inhibition.

    PubMed

    Gao, Shumei; Zhao, Mingxing; Chen, Yang; Yu, Meijuan; Ruan, Wenquan

    2015-12-01

    The anaerobic digestion (AD) of protein-rich substrates is generally inhibited by ammonia. In this study, ammonia-tolerant acclimation was exposed to a stepwise in situ ammonia stress during the continuous AD of solid residual kitchen waste by using a continuous stirred tank reactor with a 50 L active volume. The reactor worked well during the acclimation process, with an average daily biogas production of 58 L/d, an effluent soluble chemical oxygen demand of 7238 mg/L, a volatile fatty acid (VFA) content of 578 mg/L, and a VFA/alkalinity ratio of less than 0.4. Moreover, ammonia stress enhanced the activity of Coenzyme F420. The results of high-throughput 16S rDNA sequencing showed that ammonia stress increased the relative abundance of Firmicutes bacteria and hydrogenotrophic methanogens but decreased the abundance of acetotrophic methanogens. This microbial community shift was proposed to be an in situ response strategy for ammonia stress adaptation.

  1. Ammonia metabolism and hyperammonemic disorders.

    PubMed

    Walker, Valerie

    2014-01-01

    Human adults produce around 1000 mmol of ammonia daily. Some is reutilized in biosynthesis. The remainder is waste and neurotoxic. Eventually most is excreted in urine as urea, together with ammonia used as a buffer. In extrahepatic tissues, ammonia is incorporated into nontoxic glutamine and released into blood. Large amounts are metabolized by the kidneys and small intestine. In the intestine, this yields ammonia, which is sequestered in portal blood and transported to the liver for ureagenesis, and citrulline, which is converted to arginine by the kidneys. The amazing developments in NMR imaging and spectroscopy and molecular biology have confirmed concepts derived from early studies in animals and cell cultures. The processes involved are exquisitely tuned. When they are faulty, ammonia accumulates. Severe acute hyperammonemia causes a rapidly progressive, often fatal, encephalopathy with brain edema. Chronic milder hyperammonemia causes a neuropsychiatric illness. Survivors of severe neonatal hyperammonemia have structural brain damage. Proposed explanations for brain edema are an increase in astrocyte osmolality, generally attributed to glutamine accumulation, and cytotoxic oxidative/nitrosative damage. However, ammonia neurotoxicity is multifactorial, with disturbances also in neurotransmitters, energy production, anaplerosis, cerebral blood flow, potassium, and sodium. Around 90% of hyperammonemic patients have liver disease. Inherited defects are rare. They are being recognized increasingly in adults. Deficiencies of urea cycle enzymes, citrin, and pyruvate carboxylase demonstrate the roles of isolated pathways in ammonia metabolism. Phenylbutyrate is used routinely to treat inherited urea cycle disorders, and its use for hepatic encephalopathy is under investigation. PMID:25735860

  2. Ammonia Ice Clouds on Jupiter

    NASA Technical Reports Server (NTRS)

    2007-01-01

    The top cloud layer on Jupiter is thought to consist of ammonia ice, but most of that ammonia 'hides' from spectrometers. It does not absorb light in the same way ammonia does. To many scientists, this implies that ammonia churned up from lower layers of the atmosphere 'ages' in some way after it condenses, possibly by being covered with a photochemically generated hydrocarbon mixture. The New Horizons Linear Etalon Imaging Spectral Array (LEISA), the half of the Ralph instrument that is able to 'see' in infrared wavelengths that are absorbed by ammonia ice, spotted these clouds and watched them evolve over five Jupiter days (about 40 Earth hours). In these images, spectroscopically identified fresh ammonia clouds are shown in bright blue. The largest cloud appeared as a localized source on day 1, intensified and broadened on day 2, became more diffuse on days 3 and 4, and disappeared on day 5. The diffusion seemed to follow the movement of a dark spot along the boundary of the oval region. Because the source of this ammonia lies deeper than the cloud, images like these can tell scientists much about the dynamics and heat conduction in Jupiter's lower atmosphere.

  3. ENGINEERING DESIGN CONFIGURATIONS FOR BIOLOGICAL AMMONIA REMOVAL

    EPA Science Inventory

    Many regions in the United States have excessive levels of nutrients including ammonia in their source waters. For example, farming and agricultural sources of ammonia in the Midwest contribute to relatively high levels of ammonia in many ground waters. Although ammonia in water ...

  4. ROADSIDE AMMONIA MEASUREMENTS USING OPTICAL REMOTE SENSING INSTRUMENTS

    EPA Science Inventory

    Fine particles less than 2.5 microns in diameter have been identified as a causal agent of excess mortality and other undesirable health impacts. A large part of these airborne particles, generally more than one-half, are formed in the atmosphere by reactions of ammonia with acid...

  5. Ammonia as a component of fruit fly attractants.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Abstract Fruit flies in the genus Anastrepha, especially the reproductive age females, are attracted to protein baits. Synthetic lures based on the principal components of protein degradation, especially ammonia along with acetic acid, were tested against three of the most economically important Ana...

  6. Ammonia Formulations and Capture of Anastrepha Fruit Flies (Diptera: Tephritidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fruit flies in the genus Anastrepha, especially the reproductive age females, are attracted in numbers to protein baits. Synthetic lures based on the principle components of protein degradation, especially ammonia along with acetic acid, were tested against three of the most economically important ...

  7. Getter materials for cracking ammonia

    DOEpatents

    Boffito, Claudio; Baker, John D.

    1999-11-02

    A method is provided for cracking ammonia to produce hydrogen. The method includes the steps of passing ammonia over an ammonia-cracking catalyst which is an alloy including (1) alloys having the general formula Zr.sub.1-x Ti.sub.x M.sub.1 M.sub.2, wherein M.sub.1 and M.sub.2 are selected independently from the group consisting of Cr, Mn, Fe, Co, and Ni, and x is between about 0.0 and about 1.0 inclusive; and between about 20% and about 50% Al by weight. In another aspect, the method of the invention is used to provide methods for operating hydrogen-fueled internal combustion engines and hydrogen fuel cells. In still another aspect, the present invention provides a hydrogen-fueled internal combustion engine and a hydrogen fuel cell including the above-described ammonia-cracking catalyst.

  8. First detection of ammonia (NH3) in the upper troposphere

    NASA Astrophysics Data System (ADS)

    Höpfner, Michael; Volkamer, Rainer; Grabowski, Udo; Grutter de la Mora, Michel; Orphal, Johannes; Stiller, Gabriele; von Clarmann, Thomas

    2016-04-01

    Ammonia (NH3) is the major alkaline trace gas in the troposphere. Neutralization of atmospheric acids, like HNO3 and H2SO4, leads to formation of ammonium nitrate and ammonium sulfate aerosols. Further, there are indications that NH3 may enhance nucleation of sulfuric acid aerosols by stabilization of sulfuric acid clusters. By far the largest source of ammonia is agricultural food production. Major global emissions are located in S-E Asia as e.g. shown by satellite nadir observations. Besides its importance with respect to air quality issues, an increase of ammonia emissions in the 21st century might lead to a significant climate radiative impact through aerosol formation. In spite of its significance, there is a lack of observational information on the global distribution of NH3 in the mid- and upper troposphere. Observational evidence, however, would be important for testing e.g. model results on the fate of ammonia from its source regions on ground to altitudes up to the tropopause. In this contribution we will show, to our knowledge, the first unequivocal detection of ammonia in the upper troposphere. This result has been achieved through analysis of infrared limb-emission observations performed with the MIPAS (Michelson Interferometer for Passive Atmospheric Sounding) instrument on board the Envisat satellite from 2002-2012. On a global scale, enhanced values of ammonia have been measured in the upper tropospheric region influenced by the Asian monsoon. We will present a quantitative analysis of the retrieved concentrations of NH3 including an error assessment and further retrieval diagnostics. The results will be discussed with respect to the variability of NH3 locally within the Asian monsoon region's upper troposphere and at different years. Further, we will show comparisons between global distributions of NH3 from published model simulations and our observational dataset from MIPAS.

  9. DEVELOPMENT AND SELECTION OF AMMONIA EMISSION FACTORS FOR THE 1985 NAPAP EMISSIONS INVENTORY

    EPA Science Inventory

    The report, prepared for the National Acid Precipitation Assessment Program (NAPAP), identifies the most appropriate ammonia (NH3) emission factors available for inclusion in the 1985 NAPAP Emissions Inventory. H3 emission factors developed for several new NAPAP source categories...

  10. Evaluation of chemical amendments to reduce ammonia volatilization from poultry litter.

    PubMed

    Moore, P A; Daniel, T C; Edwards, D R; Miller, D M

    1996-03-01

    Ammonia volatilization from poultry litter often causes high levels of atmospheric ammonia in poultry houses, which is detrimental to both farm workers and birds. Ammonia emissions from houses also aggravate environmental problems, such as acid rain, and result in a loss of fertilizer nitrogen. The objectives of this study were to determine the effect of litter amendments on ammonia volatilization and to determine the effect of these amendments on nitrogen and phosphorus content in litter. The results of this research indicate that alum [Al2(SO4)3.18H2O], ferrous sulfate (FeSO4.7H2O), and phosphoric acid (H3PO4) dramatically reduce ammonia volatilization form litter. The amount of ammonia lost from litter treated with sodium bisulfate (NaHSO4) and a proprietory product made of Ca-Fe silicate with a phosphoric acid coating was not different from the control (untreated litter). Aluminum sulfate (alum) and ferrous sulfate also reduced water soluble P concentrations in litter, whereas phosphoric acid greatly increased water-soluble P levels. The most effective compound evaluated with respect to reducing both ammonia loss and P solubility was alum.

  11. Method for the Determination of Ammonia in Mainstream Cigarette Smoke Using Ion Chromatography

    PubMed Central

    Watson, Christina Vaughan; Feng, June; Valentin-Blasini, Liza; Stanelle, Rayman; Watson, Clifford H.

    2016-01-01

    Ammonia in mainstream smoke is present in both the particulate and vapor phases. The presence of ammonia in the cigarette filler material and smoke is of significance because of the potential role ammonia could have in raising the “smoke pH.” An increased smoke pH could shift a fraction of total nicotine to free-base nicotine, which is reportedly more rapidly absorbed by the smoker. Methods measuring ammonia in smoke typically employ acid filled impingers to trap the smoke. We developed a fast, reliable method to measure ammonia in mainstream smoke without the use of costly and time consuming impingers to examine differences in ammonia delivery. The method uses both a Cambridge filter pad and a Tedlar bag to capture particulate and vapor phases of the smoke. We quantified ammonia levels in the mainstream smoke of 50 cigarette brands from 5 manufacturers. Ammonia levels ranged from approximately 1μg to 23μg per cigarette for ISO smoking conditions and 38μg to 67μg per cigarette for Canadian intense smoking conditions and statistically significance differences were observed between brands and manufacturers. Our findings suggest that ammonia levels vary by brand and are higher under Canadian intense smoking conditions. PMID:27415766

  12. Method for the Determination of Ammonia in Mainstream Cigarette Smoke Using Ion Chromatography.

    PubMed

    Watson, Christina Vaughan; Feng, June; Valentin-Blasini, Liza; Stanelle, Rayman; Watson, Clifford H

    2016-01-01

    Ammonia in mainstream smoke is present in both the particulate and vapor phases. The presence of ammonia in the cigarette filler material and smoke is of significance because of the potential role ammonia could have in raising the "smoke pH." An increased smoke pH could shift a fraction of total nicotine to free-base nicotine, which is reportedly more rapidly absorbed by the smoker. Methods measuring ammonia in smoke typically employ acid filled impingers to trap the smoke. We developed a fast, reliable method to measure ammonia in mainstream smoke without the use of costly and time consuming impingers to examine differences in ammonia delivery. The method uses both a Cambridge filter pad and a Tedlar bag to capture particulate and vapor phases of the smoke. We quantified ammonia levels in the mainstream smoke of 50 cigarette brands from 5 manufacturers. Ammonia levels ranged from approximately 1μg to 23μg per cigarette for ISO smoking conditions and 38μg to 67μg per cigarette for Canadian intense smoking conditions and statistically significance differences were observed between brands and manufacturers. Our findings suggest that ammonia levels vary by brand and are higher under Canadian intense smoking conditions. PMID:27415766

  13. Atmospheric ammonia measurements in Houston, TX using an external cavity-quantum cascade laser-based sensor

    NASA Astrophysics Data System (ADS)

    Gong, L.; Lewicki, R.; Griffin, R. J.; Flynn, J. H.; Lefer, B. L.; Tittel, F. K.

    2010-12-01

    Ammonia (NH3) plays a significant role in atmospheric chemistry. It has many anthropogenic (e.g., agricultural crops and mineral fertilizers) and natural sources (e.g., animals, oceans, and vegetation) in the environment. In certain areas, industrial and motor vehicle activities also can contribute to increases in atmospheric NH3 levels. From a perspective of environmental concern, NH3 is a precursor of particulate matter (PM) because it can lead to production of ammonium salts (e.g., (NH4)2SO4 and NH4NO3) through chemical reactions with sulfuric and nitric acid. As a result, the abundance of NH3 in the atmosphere has a great impact on aerosol nucleation and composition. Despite this, NH3 is not regulated. It is crucial, however, to improve our understanding of the dynamics of NH3 in an industrial and urban area such as Greater Houston where atmospheric NH3 data are limited. In this study, a 10.4 µm external cavity quantum cascade laser (EC-QCL)-based sensor was developed and utilized. To monitor atmospheric NH3 at trace gas concentration levels, an amplitude modulated photo-acoustic spectroscopy (AM-PAS) technique was employed. The minimum detection limit obtained from the sensor is ~1.5 ppb for a 5-second data acquisition time. After averaging data over 300 seconds a sub-ppb NH3 concentration level can be achieved. The NH3 sensor has been deployed on the roof of a ~60-meter-high building (North Moody Tower) located on the University of Houston campus since November 2009. Several episodes of high NH3 concentrations were observed. For example, the sensor recorded a significant and lasting increase in NH3 concentrations (~21 ppb) on August 14, 2010, when a major accident occurred during the same time period on the Gulf Freeway (I-45) in Houston only 2 miles from the sampling site. The elevated concentration levels are assumed to be associated with NH3 generation from a chemical fire resulting from the collision involving two 18-wheelers, one carrying fertilizer

  14. Improving ammonia emissions in air quality modelling for France

    NASA Astrophysics Data System (ADS)

    Hamaoui-Laguel, Lynda; Meleux, Frédérik; Beekmann, Matthias; Bessagnet, Bertrand; Génermont, Sophie; Cellier, Pierre; Létinois, Laurent

    2014-08-01

    We have implemented a new module to improve the representation of ammonia emissions from agricultural activities in France with the objective to evaluate the impact of such emissions on the formation of particulate matter modelled with the air quality model CHIMERE. A novel method has been set up for the part of ammonia emissions originating from mineral fertilizer spreading. They are calculated using the one dimensional 1D mechanistic model “VOLT'AIR” which has been coupled with data on agricultural practices, meteorology and soil properties obtained at high spatial resolution (cantonal level). These emissions display high spatiotemporal variations depending on soil pH, rates and dates of fertilization and meteorological variables, especially soil temperature. The emissions from other agricultural sources (animal housing, manure storage and organic manure spreading) are calculated using the national spatialised inventory (INS) recently developed in France. The comparison of the total ammonia emissions estimated with the new approach VOLT'AIR_INS with the standard emissions provided by EMEP (European Monitoring and Evaluation Programme) used currently in the CHIMERE model shows significant differences in the spatiotemporal distributions. The implementation of new ammonia emissions in the CHIMERE model has a limited impact on ammonium nitrate aerosol concentrations which only increase at most by 10% on the average for the considered spring period but this impact can be more significant for specific pollution episodes. The comparison of modelled PM10 (particulate matter with aerodynamic diameter smaller than 10 μm) and ammonium nitrate aerosol with observations shows that the use of the new ammonia emission method slightly improves the spatiotemporal correlation in certain regions and reduces the negative bias on average by 1 μg m-3. The formation of ammonium nitrate aerosol depends not only on ammonia concentrations but also on nitric acid availability, which

  15. Autotrophic Ammonia Oxidation at Low pH through Urea Hydrolysis

    PubMed Central

    Burton, Simon A. Q.; Prosser, Jim I.

    2001-01-01

    Ammonia oxidation in laboratory liquid batch cultures of autotrophic ammonia oxidizers rarely occurs at pH values less than 7, due to ionization of ammonia and the requirement for ammonium transport rather than diffusion of ammonia. Nevertheless, there is strong evidence for autotrophic nitrification in acid soils, which may be carried out by ammonia oxidizers capable of using urea as a source of ammonia. To determine the mechanism of urea-linked ammonia oxidation, a ureolytic autotrophic ammonia oxidizer, Nitrosospira sp. strain NPAV, was grown in liquid batch culture at a range of pH values with either ammonium or urea as the sole nitrogen source. Growth and nitrite production from ammonium did not occur at pH values below 7. Growth on urea occurred at pH values in the range 4 to 7.5 but ceased when urea hydrolysis was complete, even though ammonia, released during urea hydrolysis, remained in the medium. The results support a mechanism whereby urea enters the cells by diffusion and intracellular urea hydrolysis and ammonia oxidation occur independently of extracellular pH in the range 4 to 7.5. A proportion of the ammonia produced during this process diffuses from the cell and is not subsequently available for growth if the extracellular pH is less than 7. Ureolysis therefore provides a mechanism for nitrification in acid soils, but a proportion of the ammonium produced is likely to be released from the cell and may be used by other soil organisms. PMID:11425707

  16. Interannual variability of ammonia concentrations over the United States: sources and implications

    NASA Astrophysics Data System (ADS)

    Schiferl, Luke D.; Heald, Colette L.; Van Damme, Martin; Clarisse, Lieven; Clerbaux, Cathy; Coheur, Pierre-François; Nowak, John B.; Neuman, J. Andrew; Herndon, Scott C.; Roscioli, Joseph R.; Eilerman, Scott J.

    2016-09-01

    The variability of atmospheric ammonia (NH3), emitted largely from agricultural sources, is an important factor when considering how inorganic fine particulate matter (PM2.5) concentrations and nitrogen cycling are changing over the United States. This study combines new observations of ammonia concentration from the surface, aboard aircraft, and retrieved by satellite to both evaluate the simulation of ammonia in a chemical transport model (GEOS-Chem) and identify which processes control the variability of these concentrations over a 5-year period (2008-2012). We find that the model generally underrepresents the ammonia concentration near large source regions (by 26 % at surface sites) and fails to reproduce the extent of interannual variability observed at the surface during the summer (JJA). Variability in the base simulation surface ammonia concentration is dominated by meteorology (64 %) as compared to reductions in SO2 and NOx emissions imposed by regulation (32 %) over this period. Introduction of year-to-year varying ammonia emissions based on animal population, fertilizer application, and meteorologically driven volatilization does not substantially improve the model comparison with observed ammonia concentrations, and these ammonia emissions changes have little effect on the simulated ammonia concentration variability compared to those caused by the variability of meteorology and acid-precursor emissions. There is also little effect on the PM2.5 concentration due to ammonia emissions variability in the summer when gas-phase changes are favored, but variability in wintertime emissions, as well as in early spring and late fall, will have a larger impact on PM2.5 formation. This work highlights the need for continued improvement in both satellite-based and in situ ammonia measurements to better constrain the magnitude and impacts of spatial and temporal variability in ammonia concentrations.

  17. Catalytic ammonia decomposition over industrial-waste-supported Ru catalysts

    SciTech Connect

    Pei Fang Ng; Li Li; Shaobin Wang; Zhonghua Zhu; Gaoqing Lu; Zifeng Yan

    2007-05-15

    Industrial solid wastes (fly ash and red mud, a by-product of the aluminium industry) have been employed as supports for preparation of Ru-based catalysts. Physical and chemical treatments on red mud were conducted and these modified supports were also used for preparation of Ru-based catalysts. Those Ru catalysts were characterized by various techniques such as N2 adsorption, H{sub 2} adsorption, XRD, XPS, and temperature-programmed reduction (TPR), and were then tested for catalytic ammonia decomposition to hydrogen. It was found that red-mud-supported Ru catalyst exhibits higher ammonia conversion and hydrogen production than fly-ash-supported catalyst. Heat and chemical treatments of the red mud greatly improve the catalytic activity. Moreover, a combination of acid and heat treatments produces the highest catalytic conversion of ammonia. 35 refs., 4 figs., 4 tabs.

  18. Counteracting ammonia inhibition in anaerobic digestion by removal with a hollow fiber membrane contactor.

    PubMed

    Lauterböck, B; Ortner, M; Haider, R; Fuchs, W

    2012-10-01

    The aim of the current study was to investigate the feasibility of membrane contactors for continuous ammonia (NH₃-N) removal in an anaerobic digestion process and to counteract ammonia inhibition. Two laboratory anaerobic digesters were fed slaughterhouse wastes with ammonium (NH₄⁺) concentrations ranging from 6 to 7.4 g/L. One reactor was used as reference reactor without any ammonia removal. In the second reactor, a hollow fiber membrane contactor module was used for continuous ammonia removal. The hollow fiber membranes were directly submerged into the digestate of the anaerobic reactor. Sulfuric acid was circulated in the lumen as an adsorbent solution. Using this set up, the NH₄⁺-N concentration in the membrane reactor was significantly reduced. Moreover the extraction of ammonia lowered the pH by 0.2 units. In combination that led to a lowering of the free NH₃-N concentration by about 70%. Ammonia inhibition in the reference reactor was observed when the concentration exceeded 6 g/L NH₄⁺-N or 1-1.2 g/L NH₃-N. In contrast, in the membrane reactor the volatile fatty acid concentration, an indicator for process stability, was much lower and a higher gas yield and better degradation was observed. The chosen approach offers an appealing technology to remove ammonia directly from media having high concentrations of solids and it can help to improve process efficiency in anaerobic digestion of ammonia rich substrates.

  19. Global Seabird Ammonia Emissions

    NASA Astrophysics Data System (ADS)

    Riddick, S. N.; Blackall, T. D.; Dragosits, U.; Daunt, F. H.; Braban, C. F.; Tang, Y. S.; Trathan, P.; Wanless, S.; Sutton, M. A.

    2010-12-01

    Seabird colonies represent a major source of atmospheric ammonia (NH3) in remote coastal and marine systems in temperate, tropical and polar regions. Previous studies have shown that NH3 emissions from Scottish seabird colonies were substantial - of similar magnitude to the most intensive agricultural point source emissions. The UK data were used to model global seabird NH3 emissions and suggested that penguins are a major source of emissions on and around the Antarctic continent. The largest seabird colonies are in the order of millions of seabirds. Due to the isolation of these colonies from anthropogenic nitrogen sources, they may play a major role in the nitrogen cycle within these ecosystems. A global seabird database was constructed and used in conjunction with a species-specific seabird bioenergetics model to map the locations of NH3 emissions from seabird colonies. The accuracy of the modelled emissions was validated with field data of NH3 emissions measured at key seabird colonies in different climatic regions of the world: temperate (Isle of May, Scotland), tropical (Ascension Island) and polar (Signy Island, South Georgia). The field data indicated good agreement between modelled and measured NH3 emissions. The measured NH3 emissions also showed the variability of emission with climate. Climate dependence of seabird NH3 emissions may have further implications under a changing global climate. Seabird colonies represent NH3 emission ‘hotspots’, often far from anthropogenic sources, and are likely to be the major source of nitrogen input to these remote coastal ecosystems. The direct manuring by seabirds at colony locations may strongly influence species richness and biodiversity. The subsequent volatilisation and deposition of NH3 increases the spatial extent of seabird influence on nitrogen cycling in their local ecosystem. As many seabird populations are fluctuating due to changing food supply, climate change or anthropogenic pressures, these factors

  20. MEASUREMENT OF AMMONIA RELEASE FROM SALTSTONE

    SciTech Connect

    Zamecnik, J; Alex Cozzi, A

    2009-01-15

    SRNL was requested by WSRC Waste Solidification Engineering to characterize the release of ammonia from saltstone curing at 95 C by performing experimental testing. These tests were performed with an MCU-type Tank 50H salt simulant containing 0, 50, and 200 mg/L ammonia. The testing program showed that above saltstone made from the 200 mg/L ammonia simulant, the vapor space ammonia concentration was about 2.7 mg/L vapor at 95 C. An upper 95% confidence value for this concentration was found to be 3.9 mg/L. Testing also showed that ammonia was chemically generated from curing saltstone at 95 C; the amount of ammonia generated was estimated to be equivalent to 121 mg/L additional ammonia in the salt solution feed. Even with chemical generation, the ammonia release from saltstone was found to be lower than its release from salt solution only with 200 mg/L ammonia.

  1. Simple and inexpensive quantification of ammonia in whole blood.

    PubMed

    Ayyub, Omar B; Behrens, Adam M; Heligman, Brian T; Natoli, Mary E; Ayoub, Joseph J; Cunningham, Gary; Summar, Marshall; Kofinas, Peter

    2015-01-01

    Quantification of ammonia in whole blood has applications in the diagnosis and management of many hepatic diseases, including cirrhosis and rare urea cycle disorders, amounting to more than 5 million patients in the United States. Current techniques for ammonia measurement suffer from limited range, poor resolution, false positives or large, complex sensor set-ups. Here we demonstrate a technique utilizing inexpensive reagents and simple methods for quantifying ammonia in 100 μL of whole blood. The sensor comprises a modified form of the indophenol reaction, which resists sources of destructive interference in blood, in conjunction with a cation-exchange membrane. The presented sensing scheme is selective against other amine containing molecules such as amino acids and has a shelf life of at least 50 days. Additionally, the resulting system has high sensitivity and allows for the accurate reliable quantification of ammonia in whole human blood samples at a minimum range of 25 to 500 μM, which is clinically for rare hyperammonemic disorders and liver disease. Furthermore, concentrations of 50 and 100 μM ammonia could be reliably discerned with p = 0.0001.

  2. A mass transfer model of ammonia volatilisation from anaerobic digestate

    SciTech Connect

    Whelan, M.J.; Everitt, T.; Villa, R.

    2010-10-15

    Anaerobic digestion (AD) is becoming increasingly popular for treating organic waste. The methane produced can be burned to generate electricity and the digestate, which is high in mineral nitrogen, can be used as a fertiliser. In this paper we evaluate potential losses of ammonia via volatilisation from food waste anaerobic digestate using a closed chamber system equipped with a sulphuric acid trap. Ammonia losses represent a pollution source and, over long periods could reduce the agronomic value of the digestate. Observed ammonia losses from the experimental system were linear with time. A simple non-steady-state partitioning model was developed to represent the process. After calibration, the model was able to describe the behaviour of ammonia in the digestate and in the trap very well. The average rate of volatilisation was approximately 5.2 g N m{sup -2} week{sup -1}. The model was used to extrapolate the findings of the laboratory study to a number of AD storage scenarios. The simulations highlight that open storage of digestate could result in significant losses of ammonia to the atmosphere. Losses are predicted to be relatively minor from covered facilities, particularly if depth to surface area ratio is high.

  3. Monodisperse Pt Nanoparticles Assembled on Reduced Graphene Oxide: Highly Efficient and Reusable Catalyst for Methanol Oxidation and Dehydrocoupling of Dimethylamine-Borane (DMAB).

    PubMed

    Yildiz, Yunus; Erken, Esma; Pamuk, Handan; Sert, Hakan; Sen, Fatih

    2016-06-01

    Herein, monodisperse platinum (0) nanocatalyst assembled on reduced graphene oxide (Pt(0)@RGO) was easily and reproducibly prepared by the double solvent reduction method at room temperature. Pt(0)@RGO was characterized by X-ray diffraction (XRD), X-ray photoelectron microscopy (XPS) and transmission electron microscopy (TEM) measurements that verify the formation of monodisperse Pt (0) nanoparticles on RGO. The catalytic and electrocatalytic performances of Pt(0) @ RGO in terms of activity, isolability and reusability were investigated for both methanol oxidation and the dehydrocoupling of dimethylamine-borane (DMAB) in which Pt(0)@RGO was found to be highly active and reusable heterogeneous catalyst even at room temperature. The prepared nanoparticles can also electrocatalyze methanol oxidation with very high electrochemical activities (5.64 A/cm2 at 0.58 V for methanol). The activation energy (Ea), activation enthalpy (ΔH#), and activation entropy (ΔS#) for DMAB dehydrogenation were calculated to be 59.33 kJ mol(-1), 56.79 kJ mol(-1) and -151.68 J mol(-1) K(-1), respectively. The exceptional stability of new Pt(0) @ RGO nanoparticles towards agglomeration, leaching and CO poisoning allow these particles to be recycled and reused in the catalysis of DMAB dehydrogenation and methanol oxidation. After four subsequent reaction and recovery cycles, Pt(0) @ RGO retained ≥ 75% activity towards the complete dehydrogenation of DMAB. PMID:27427656

  4. Effect of vortex flows on ammonia oxidation

    SciTech Connect

    Beskov, V.S.; Shpinel', E.E.

    1988-09-01

    The oxidation of ammonia over platinum sieve catalysts was investigated given the vortex flows found in industrial contact units. Mathematical and physical models were used to assess the influence of vortices on ammonia oxidation. The flow pattern of the ammonia-air mixture in the reactor was modeled as a stream with a partial recycle. It is shown that vortex flows reduce the conversion of ammonia to nitrogen monoxide and increase the passage of unconverted ammonia through the catalyst sieve. Over long contact periods, the main effect of vortices is to increase the passage of unconverted ammonia, which may lead to the formation of explosive compounds.

  5. The Ammonia Dimer Revisited

    NASA Astrophysics Data System (ADS)

    Dawes, Richard; Van Der Avoird, Ad

    2012-06-01

    The conclusion from microwave spectra by Nelson, Fraser, and Klemperer that the ammonia dimer has a nearly cyclic structure led to much debate about the issue of whether (NH_3)_2 is hydrogen bonded. This structure was surprising because most {ab initio} calculations led to a classical, nearly linear, hydrogen-bonded structure. An obvious explanation of the discrepancy between the outcome of these calculations and the microwave data which led Nelson {et al.} to their ``surprising structure'' might be the effect of vibrational averaging: the electronic structure calculations focus on finding the minimum of the intermolecular potential, the experiment gives a vibrationally averaged structure. Isotope substitution studies seemed to indicate, however, that the complex is nearly rigid. Additional data became available from high-resolution molecular beam far-infrared spectroscopy in the Saykally group. These spectra, displaying large tunneling splittings, indicate that the complex is very floppy. The seemingly contradictory experimental data were explained when it became possible to calculate the vibration-rotation-tunneling (VRT) states of the complex on a six-dimensional intermolecular potential surface. The potential used was a simple model potential, with parameters fitted to the far-infrared data. Now, for the first time, a six-dimensional potential was computed by high level {ab initio} methods and this potential will be used in calculations of the VRT states of (NH_3)_2 and (ND_3)_2. So, we will finally be able to answer the question whether the conclusions from the model calculations are indeed a valid explanation of the experimental data. D. Nelson, G. T. Fraser, and W. Klemperer J. Chem. Phys. 83 6201 (1985) J. G. Loeser, C. A. Schmuttenmaer, R. C. Cohen, M. J. Elrod, D. W. Steyert, R. J. Saykally, R. E. Bumgarner, and G. A. Blake J. Chem. Phys. 97 4727 (1992) E. H. T. Olthof, A. van der Avoird, and P. E. S. Wormer J. Chem. Phys. 101 8430 (1994) E. H. T. Olthof

  6. Role of the aerosol phase state in ammonia/amines exchange reactions.

    PubMed

    Chan, Lap P; Chan, Chak K

    2013-06-01

    The exchange reaction of ammonia in (NH4)2SO4 with an amine and the corresponding reverse reaction of amines in aminium sulfates with ammonia were investigated using an electrodynamic balance coupled with a Raman spectrometer. The temporal changes in particle mass, chemical composition, and phase state were simultaneously monitored. When the salt particles were in an aqueous state at elevated relative humidities (RHs), the exchange of ammonia/amine vapors in the particle phase was reversible. The exchange rates of aqueous particles were in general higher than those of their corresponding solid counterparts. An aqueous phase was essential for the effective displacement of ammonia and amines. Aminium salts in different phase states and with different evaporation characteristics showed remarkably different reaction behaviors in ammonia vapor. The less compact amorphous aminium sulfate solids were more susceptible to ammonia exchange than the crystalline solids. The aminium salts in a liquid state exhibited substantial amine evaporation at <3% RH and formed acidic bisulfate. Under ammonia exposure, these acidic aminium droplets underwent both neutralization and displacement reactions. Stable solid salts containing ammonium, aminium, sulfate, and bisulfate were formed and hindered further reactions. The result suggests that ambient aminium sulfates may be acidic. Overall, the phase states of the ammonium and aminium salt particles crucially determine the heterogeneous reaction rates and final product properties and identities. PMID:23668831

  7. Identifying Potential Mechanisms Enabling Acidophily in the Ammonia-Oxidizing Archaeon “Candidatus Nitrosotalea devanaterra”

    PubMed Central

    Sayavedra-Soto, Luis A.; Gallois, Nicolas; Schouten, Stefan; Stein, Lisa Y.; Prosser, James I.; Nicol, Graeme W.

    2016-01-01

    Ammonia oxidation is the first and rate-limiting step in nitrification and is dominated by two distinct groups of microorganisms in soil: ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB). AOA are often more abundant than AOB and dominate activity in acid soils. The mechanism of ammonia oxidation under acidic conditions has been a long-standing paradox. While high rates of ammonia oxidation are frequently measured in acid soils, cultivated ammonia oxidizers grew only at near-neutral pH when grown in standard laboratory culture. Although a number of mechanisms have been demonstrated to enable neutrophilic AOB growth at low pH in the laboratory, these have not been demonstrated in soil, and the recent cultivation of the obligately acidophilic ammonia oxidizer “Candidatus Nitrosotalea devanaterra” provides a more parsimonious explanation for the observed high rates of activity. Analysis of the sequenced genome, transcriptional activity, and lipid content of “Ca. Nitrosotalea devanaterra” reveals that previously proposed mechanisms used by AOB for growth at low pH are not essential for archaeal ammonia oxidation in acidic environments. Instead, the genome indicates that “Ca. Nitrosotalea devanaterra” contains genes encoding both a predicted high-affinity substrate acquisition system and potential pH homeostasis mechanisms absent in neutrophilic AOA. Analysis of mRNA revealed that candidate genes encoding the proposed homeostasis mechanisms were all expressed during acidophilic growth, and lipid profiling by high-performance liquid chromatography–mass spectrometry (HPLC-MS) demonstrated that the membrane lipids of “Ca. Nitrosotalea devanaterra” were not dominated by crenarchaeol, as found in neutrophilic AOA. This study for the first time describes a genome of an obligately acidophilic ammonia oxidizer and identifies potential mechanisms enabling this unique phenotype for future biochemical characterization. PMID:26896134

  8. Identifying Potential Mechanisms Enabling Acidophily in the Ammonia-Oxidizing Archaeon "Candidatus Nitrosotalea devanaterra".

    PubMed

    Lehtovirta-Morley, Laura E; Sayavedra-Soto, Luis A; Gallois, Nicolas; Schouten, Stefan; Stein, Lisa Y; Prosser, James I; Nicol, Graeme W

    2016-05-01

    Ammonia oxidation is the first and rate-limiting step in nitrification and is dominated by two distinct groups of microorganisms in soil: ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB). AOA are often more abundant than AOB and dominate activity in acid soils. The mechanism of ammonia oxidation under acidic conditions has been a long-standing paradox. While high rates of ammonia oxidation are frequently measured in acid soils, cultivated ammonia oxidizers grew only at near-neutral pH when grown in standard laboratory culture. Although a number of mechanisms have been demonstrated to enable neutrophilic AOB growth at low pH in the laboratory, these have not been demonstrated in soil, and the recent cultivation of the obligately acidophilic ammonia oxidizer "Candidatus Nitrosotalea devanaterra" provides a more parsimonious explanation for the observed high rates of activity. Analysis of the sequenced genome, transcriptional activity, and lipid content of "Ca Nitrosotalea devanaterra" reveals that previously proposed mechanisms used by AOB for growth at low pH are not essential for archaeal ammonia oxidation in acidic environments. Instead, the genome indicates that "Ca Nitrosotalea devanaterra" contains genes encoding both a predicted high-affinity substrate acquisition system and potential pH homeostasis mechanisms absent in neutrophilic AOA. Analysis of mRNA revealed that candidate genes encoding the proposed homeostasis mechanisms were all expressed during acidophilic growth, and lipid profiling by high-performance liquid chromatography-mass spectrometry (HPLC-MS) demonstrated that the membrane lipids of "Ca Nitrosotalea devanaterra" were not dominated by crenarchaeol, as found in neutrophilic AOA. This study for the first time describes a genome of an obligately acidophilic ammonia oxidizer and identifies potential mechanisms enabling this unique phenotype for future biochemical characterization. PMID:26896134

  9. ATMOSPHERIC CONCENTRATIONS OF AMMONIA AND AMMONIUM AT AN AGRICULTURAL SITE IN THE SOUTHEAST UNITED STATES

    EPA Science Inventory

    In this study, we present approximately 1 year (October 1998 - September 1999) of 12-hour mean ammonia [NH3], ammonium [NH4(+)], hydrochloric acid [HCl], nitrate [NO3(-)], nitric acid [HNO3], nitrous acid [HNO2], sulfate [SO4(- -)], and sulfur dioxide [SO2] concentrations measure...

  10. MONITORING AMBIENT AMMONIA CHEMISTRY IN AN AGRICULTURAL REGION WITH A LOW DENSITY OF ANIMAL PRODUCTION

    EPA Science Inventory

    We present several years of ambient ammonia, ammonium, hydrochloric acid, chloride, nitric acid, nitrate, nitrous acid, sulfur dioxide, and sulfate concentrations at a rural site in the Coastal Plain region of North Carolina. Also, the air chemistry of Lewiston, NC and Clinton, N...

  11. Catalytic Organometallic Reactions of Ammonia

    PubMed Central

    Klinkenberg, Jessica L.

    2012-01-01

    Until recently, ammonia had rarely succumbed to catalytic transformations with homogeneous catalysts, and the development of such reactions that are selective for the formation of single products under mild conditions has encountered numerous challenges. However, recently developed catalysts have allowed several classes of reactions to create products with nitrogen-containing functional groups from ammonia. These reactions include hydroaminomethylation, reductive amination, alkylation, allylic substitution, hydroamination, and cross-coupling. This Minireview describes examples of these processes and the factors that control catalyst activity and selectivity. PMID:20857466

  12. Roles of bovine serum albumin and copper in the assay and stability of ammonia monooxygenase activity in vitro.

    PubMed Central

    Juliette, L Y; Hyman, M R; Arp, D J

    1995-01-01

    We investigated the effects of bovine serum albumin (BSA) on both the assay and the stability of ammonia-oxidizing activity in cell extracts of Nitrosomonas europaea. Ammonia-dependent O2 uptake activity of freshly prepared extracts did not require BSA. However, a dependence on BSA developed in extracts within a short time. The role of BSA in the assay of ammonia-oxidizing activity apparently is to absorb endogenous free fatty acids which are present in the extracts, because (i) only proteins which bind fatty acids, e.g., BSA or beta-lactoglobulin, supported ammonia-oxidizing activity; (ii) exogenous palmitoleic acid completely inhibited ammonia-dependent O2 uptake activity; (iii) the inhibition caused by palmitoleic acid was reversed only by proteins which bind fatty acids; and (iv) the concentration of endogenous free palmitoleic acid increased during aging of cell extracts. Additionally, the presence of BSA (10 mg/ml) or CuCl2 (500 microM) stabilized ammonia-dependent O2 uptake activity for 2 to 3 days at 4 degrees C. The stabilizing effect of BSA or CuCl2 was apparently due to an inhibition of lipolysis, because both additives inhibited the increase in concentrations of free palmitoleic acid in aging extracts. Other additives which are known to modify lipase activity were also found to stabilize ammonia-oxidizing activity. These additives included HgCl2, lecithin, and phenylmethylsulfonyl fluoride. PMID:7665467

  13. A modern view of phenylalanine ammonia lyase.

    PubMed

    MacDonald, M Jason; D'Cunha, Godwin B

    2007-06-01

    Phenylalanine ammonia lyase (PAL; E.C.4.3.1.5), which catalyses the biotransformation of L-phenylalanine to trans-cinnamic acid and ammonia, was first described in 1961 by Koukol and Conn. Since its discovery, much knowledge has been gathered with reference to the enzyme's catabolic role in microorganisms and its importance in the phenyl propanoid pathway of plants. The 3-dimensional structure of the enzyme has been characterized using X-ray crystallography. This has led to a greater understanding of the mechanism of PAL-catalyzed reactions, including the discovery of a recently described cofactor, 3,5-dihydro-5-methyldiene-4H-imidazol-4-one. In the past 3 decades, PAL has gained considerable significance in several clinical, industrial, and biotechnological applications. The reversal of the normal physiological reaction can be effectively employed in the production of optically pure L-phenylalanine, which is a precursor of the noncalorific sweetener aspartame (L-phenylalanyl-L-aspartyl methyl ester). The enzyme's natural ability to break down L-phenylalanine makes PAL a reliable treatment for the genetic condition phenylketonuria. In this mini-review, we discuss prominent details relating to the physiological role of PAL, the mechanism of catalysis, methods of determination and purification, enzyme kinetics, and enzyme activity in nonaqueous media. Two topics of current study on PAL, molecular biology and crystal structure, are also discussed. PMID:17612622

  14. A modern view of phenylalanine ammonia lyase.

    PubMed

    MacDonald, M Jason; D'Cunha, Godwin B

    2007-06-01

    Phenylalanine ammonia lyase (PAL; E.C.4.3.1.5), which catalyses the biotransformation of L-phenylalanine to trans-cinnamic acid and ammonia, was first described in 1961 by Koukol and Conn. Since its discovery, much knowledge has been gathered with reference to the enzyme's catabolic role in microorganisms and its importance in the phenyl propanoid pathway of plants. The 3-dimensional structure of the enzyme has been characterized using X-ray crystallography. This has led to a greater understanding of the mechanism of PAL-catalyzed reactions, including the discovery of a recently described cofactor, 3,5-dihydro-5-methyldiene-4H-imidazol-4-one. In the past 3 decades, PAL has gained considerable significance in several clinical, industrial, and biotechnological applications. The reversal of the normal physiological reaction can be effectively employed in the production of optically pure L-phenylalanine, which is a precursor of the noncalorific sweetener aspartame (L-phenylalanyl-L-aspartyl methyl ester). The enzyme's natural ability to break down L-phenylalanine makes PAL a reliable treatment for the genetic condition phenylketonuria. In this mini-review, we discuss prominent details relating to the physiological role of PAL, the mechanism of catalysis, methods of determination and purification, enzyme kinetics, and enzyme activity in nonaqueous media. Two topics of current study on PAL, molecular biology and crystal structure, are also discussed.

  15. Influences of ammonia contamination on leaching from air-pollution-control residues.

    PubMed

    Guan, Zhenzhen; Chen, Dezhen; Astrup, Thomas Fruergaard

    2014-12-01

    Application of selective non-catalytic reduction systems at municipal solid waste incinerators (MSWIs) often involves over-stoichiometric injection of ammonia into flue gases. Un-reacted ammonia may be deposited on fly ash particles and can ultimately influence the leaching behaviour of air-pollution-control (APC) residues. Batch tests were conducted to investigate the impacts of ammonia levels on leaching of a range of metals (sodium, potassium, calcium, aluminium, chromium, iron, lead, cadmium, copper, nickel and zinc), as well as chloride and dissolved organic carbon (DOC). Specific conductivity was also identified to reflect the soluble components. The results showed that with ammonia concentrations rising from a background level of 4 to 26,400 mg l(-1), the specific conductivity increased by 2-7 times as pH varied from alkaline to acidic values. DOC release was also significantly enhanced with high ammonia levels of 1400 mg l(-1) or higher at pH > 9; however at these high ammonia concentrations, the role of DOC in cadmium, copper, nickel and zinc leaching was negligible. Based on the experimental data, chloride, sodium and potassium were leached at high concentrations regardless of pH and ammonia concentrations. For aluminium, chromium, iron and lead, ammonia had little impact on their leaching behaviour. With respect to cadmium, copper, nickel and zinc, high ammonia concentrations significantly increased leaching in the pH range of 8-12 due to the formation of metal-ammonia complexes, which was also proved in the speciation calculations. However, the overall results suggest that typical levels of ammonia injection in MSWIs are not likely to affect metal leaching from APC residues. PMID:25147306

  16. Influences of ammonia contamination on leaching from air-pollution-control residues.

    PubMed

    Guan, Zhenzhen; Chen, Dezhen; Astrup, Thomas Fruergaard

    2014-12-01

    Application of selective non-catalytic reduction systems at municipal solid waste incinerators (MSWIs) often involves over-stoichiometric injection of ammonia into flue gases. Un-reacted ammonia may be deposited on fly ash particles and can ultimately influence the leaching behaviour of air-pollution-control (APC) residues. Batch tests were conducted to investigate the impacts of ammonia levels on leaching of a range of metals (sodium, potassium, calcium, aluminium, chromium, iron, lead, cadmium, copper, nickel and zinc), as well as chloride and dissolved organic carbon (DOC). Specific conductivity was also identified to reflect the soluble components. The results showed that with ammonia concentrations rising from a background level of 4 to 26,400 mg l(-1), the specific conductivity increased by 2-7 times as pH varied from alkaline to acidic values. DOC release was also significantly enhanced with high ammonia levels of 1400 mg l(-1) or higher at pH > 9; however at these high ammonia concentrations, the role of DOC in cadmium, copper, nickel and zinc leaching was negligible. Based on the experimental data, chloride, sodium and potassium were leached at high concentrations regardless of pH and ammonia concentrations. For aluminium, chromium, iron and lead, ammonia had little impact on their leaching behaviour. With respect to cadmium, copper, nickel and zinc, high ammonia concentrations significantly increased leaching in the pH range of 8-12 due to the formation of metal-ammonia complexes, which was also proved in the speciation calculations. However, the overall results suggest that typical levels of ammonia injection in MSWIs are not likely to affect metal leaching from APC residues.

  17. Alleviating versus stimulating effects of bicarbonate on the growth of Vallisneria natans under ammonia stress.

    PubMed

    Dou, Yanyan; Wang, Baozhong; Chen, Liangyan; Yin, Daqiang

    2013-08-01

    Bicarbonate plays a crucial role in limiting the growth of submersed aquatic macrophytes in eutrophic lakes, and high ammonia is often toxic to macrophytes. In order to evaluate the combined effect of HCO3 (-) and total ammonia (i.e., the total of NH3 and NH4 (+)) on submersed macrophytes Vallisneria natans, the growth and physiological response of V. natans in the presence of HCO3 (-) and ammonia were studied. The results showed that with the increase of ammonia, morphological parameters of V. natans declined. In contrast, increased HCO3 (-) concentration stimulated the growth of V. natans, especially when the NH4 (+)-N/NO3 (-)-N ratio was 1:7. High ammonia concentration induced excess free amino acids (FAA) accumulation and soluble carbohydrates (SC) depletion in plant tissues. However, the elevated HCO3 (-) promoted the synthesis of SC and rendered the decrease of FAA/SC ratio. The results also suggested that HCO3 (-) could partially alleviate the stress of ammonia, as evidenced by the decrease of FAA/SC ratio and the growth enhancement of V. natans when the ammonia concentration was 0.58 mg L(-1). Given the fact that HCO3 (-) is probably the dominant available carbon source in most eutrophic lakes, the ability of V. natans to use HCO3 (-) for SC synthesis may explain the alleviating effect of HCO3 (-) on V. natans under ammonia stress. PMID:23381797

  18. Diel variation in ammonia excretion, glutamine levels, and hydration status in two species of terrestrial isopods.

    PubMed

    Wright, Jonathan C; Peña-Peralta, Mariasol

    2005-01-01

    Terrestrial isopods (suborder Oniscidea) excrete most nitrogen diurnally as volatile ammonia, and ammonia-loaded animals accumulate nonessential amino acids, which may constitute the major nocturnal nitrogen pool. This study explored the relationship between ammonia excretion, glutamine storage/mobilization, and water balance, in two sympatric species Ligidium lapetum (section Diplocheta), a hygric species; and Armadillidium vulgare (Section Crinocheta), a xeric species capable of water-vapor absorption (WVA). Ammonia excretion (12-h), tissue glutamine levels, and water contents were measured following field collection of animals at dusk and dawn. In both species, diurnal ammonia excretion exceeded nocturnal excretion four- to fivefold while glutamine levels increased four- to sevenfold during the night. Most glutamine was accumulated in the somatic tissues ("body wall"). While data support the role of glutamine in nocturnal nitrogen storage, potential nitrogen mobilization from glutamine breakdown (162 micromol g(-1) in A. vulgare) exceeds measured ammonia excretion (2.5 micromol g(-1)) over 60-fold. This may serve to generate the high hemolymph ammonia concentrations (and high P(NH3)) seen during volatilization. The energetic cost of ammonia volatilization is discussed in the light of these findings. Mean water contents were similar at dusk and dawn in both species, indicating that diel cycles of water depletion and replenishment were not occurring. PMID:15578188

  19. Diel variation in ammonia excretion, glutamine levels, and hydration status in two species of terrestrial isopods.

    PubMed

    Wright, Jonathan C; Peña-Peralta, Mariasol

    2005-01-01

    Terrestrial isopods (suborder Oniscidea) excrete most nitrogen diurnally as volatile ammonia, and ammonia-loaded animals accumulate nonessential amino acids, which may constitute the major nocturnal nitrogen pool. This study explored the relationship between ammonia excretion, glutamine storage/mobilization, and water balance, in two sympatric species Ligidium lapetum (section Diplocheta), a hygric species; and Armadillidium vulgare (Section Crinocheta), a xeric species capable of water-vapor absorption (WVA). Ammonia excretion (12-h), tissue glutamine levels, and water contents were measured following field collection of animals at dusk and dawn. In both species, diurnal ammonia excretion exceeded nocturnal excretion four- to fivefold while glutamine levels increased four- to sevenfold during the night. Most glutamine was accumulated in the somatic tissues ("body wall"). While data support the role of glutamine in nocturnal nitrogen storage, potential nitrogen mobilization from glutamine breakdown (162 micromol g(-1) in A. vulgare) exceeds measured ammonia excretion (2.5 micromol g(-1)) over 60-fold. This may serve to generate the high hemolymph ammonia concentrations (and high P(NH3)) seen during volatilization. The energetic cost of ammonia volatilization is discussed in the light of these findings. Mean water contents were similar at dusk and dawn in both species, indicating that diel cycles of water depletion and replenishment were not occurring.

  20. 27 CFR 21.96 - Ammonia, aqueous.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Ammonia, aqueous. 21.96 Section 21.96 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT... Ammonia, aqueous. (a) Alkalinity. Strongly alkaline to litmus. (b) Ammonia content. 27 to 30 percent...

  1. 27 CFR 21.96 - Ammonia, aqueous.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Ammonia, aqueous. 21.96 Section 21.96 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT... Ammonia, aqueous. (a) Alkalinity. Strongly alkaline to litmus. (b) Ammonia content. 27 to 30 percent...

  2. 27 CFR 21.96 - Ammonia, aqueous.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Ammonia, aqueous. 21.96 Section 21.96 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT... Ammonia, aqueous. (a) Alkalinity. Strongly alkaline to litmus. (b) Ammonia content. 27 to 30 percent...

  3. 27 CFR 21.96 - Ammonia, aqueous.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Ammonia, aqueous. 21.96 Section 21.96 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT... Ammonia, aqueous. (a) Alkalinity. Strongly alkaline to litmus. (b) Ammonia content. 27 to 30 percent...

  4. 46 CFR 154.1760 - Liquid ammonia.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ....1760 Liquid ammonia. The master shall ensure that no person sprays liquid ammonia into a cargo tank containing more than 8% oxygen by volume. ... 46 Shipping 5 2010-10-01 2010-10-01 false Liquid ammonia. 154.1760 Section 154.1760 Shipping...

  5. 46 CFR 154.1760 - Liquid ammonia.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ....1760 Liquid ammonia. The master shall ensure that no person sprays liquid ammonia into a cargo tank containing more than 8% oxygen by volume. ... 46 Shipping 5 2014-10-01 2014-10-01 false Liquid ammonia. 154.1760 Section 154.1760 Shipping...

  6. 46 CFR 154.1760 - Liquid ammonia.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ....1760 Liquid ammonia. The master shall ensure that no person sprays liquid ammonia into a cargo tank containing more than 8% oxygen by volume. ... 46 Shipping 5 2012-10-01 2012-10-01 false Liquid ammonia. 154.1760 Section 154.1760 Shipping...

  7. 46 CFR 154.1760 - Liquid ammonia.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ....1760 Liquid ammonia. The master shall ensure that no person sprays liquid ammonia into a cargo tank containing more than 8% oxygen by volume. ... 46 Shipping 5 2013-10-01 2013-10-01 false Liquid ammonia. 154.1760 Section 154.1760 Shipping...

  8. 46 CFR 154.1760 - Liquid ammonia.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ....1760 Liquid ammonia. The master shall ensure that no person sprays liquid ammonia into a cargo tank containing more than 8% oxygen by volume. ... 46 Shipping 5 2011-10-01 2011-10-01 false Liquid ammonia. 154.1760 Section 154.1760 Shipping...

  9. 21 CFR 573.180 - Anhydrous ammonia.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.180 Anhydrous ammonia. (a) The food additive anhydrous ammonia is applied directly...: (1)(i) The food additive anhydrous ammonia is applied as a component of an aqueous premix...

  10. 21 CFR 573.180 - Anhydrous ammonia.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.180 Anhydrous ammonia. (a) The food additive anhydrous ammonia is applied directly...: (1)(i) The food additive anhydrous ammonia is applied as a component of an aqueous premix...

  11. 21 CFR 573.180 - Anhydrous ammonia.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.180 Anhydrous ammonia. (a) The food additive anhydrous ammonia is applied directly...: (1)(i) The food additive anhydrous ammonia is applied as a component of an aqueous premix...

  12. 21 CFR 573.180 - Anhydrous ammonia.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.180 Anhydrous ammonia. (a) The food additive anhydrous ammonia is applied directly...: (1)(i) The food additive anhydrous ammonia is applied as a component of an aqueous premix...

  13. Synergistic ammonia losses from animal wastewater

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thin-layer models are commonly used to estimate ammonia emissions from liquid waste. However, such models differ in their ability to accurately reproduce observed emissions, which may be partly due to an incomplete mechanistic understanding of ammonia volatilization. In this study, ammonia release...

  14. Hydrogen production using ammonia borane

    DOEpatents

    Hamilton, Charles W; Baker, R. Thomas; Semelsberger, Troy A; Shrestha, Roshan P

    2013-12-24

    Hydrogen ("H.sub.2") is produced when ammonia borane reacts with a catalyst complex of the formula L.sub.nM-X wherein M is a base metal such as iron, X is an anionic nitrogen- or phosphorus-based ligand or hydride, and L is a neutral ancillary ligand that is a neutral monodentate or polydentate ligand.

  15. Ammonia excretion by Azobacter chroococcum

    SciTech Connect

    Narula, N.; Lakshminarayana, K.; Tauro, P.

    1981-02-01

    In recent years, research has focused attention on the development of biological systems for nitrogen fixation. In this report, two strains of Azotobacter chroococcum are identified which can excrete as much as 45 mg ammonia/ml of the culture broth in a sucrose supplemented synthetic medium.

  16. Geographic Distribution of Archaeal Ammonia Oxidizing Ecotypes in the Atlantic Ocean.

    PubMed

    Sintes, Eva; De Corte, Daniele; Haberleitner, Elisabeth; Herndl, Gerhard J

    2016-01-01

    In marine ecosystems, Thaumarchaeota are most likely the major ammonia oxidizers. While ammonia concentrations vary by about two orders of magnitude in the oceanic water column, archaeal ammonia oxidizers (AOA) vary by only one order of magnitude from surface to bathypelagic waters. Thus, the question arises whether the key enzyme responsible for ammonia oxidation, ammonia monooxygenase (amo), exhibits different affinities to ammonia along the oceanic water column and consequently, whether there are different ecotypes of AOA present in the oceanic water column. We determined the abundance and phylogeny of AOA based on their amoA gene. Two ecotypes of AOA exhibited a distribution pattern reflecting the reported availability of ammonia and the physico-chemical conditions throughout the Atlantic, and from epi- to bathypelagic waters. The distinction between these two ecotypes was not only detectable at the nucleotide level. Consistent changes were also detected at the amino acid level. These changes include substitutions of polar to hydrophobic amino acid, and glycine substitutions that could have an effect on the configuration of the amo protein and thus, on its activity. Although we cannot identify the specific effect, the ratio of non-synonymous to synonymous substitutions (dN/dS) between the two ecotypes indicates a strong positive selection between them. Consequently, our results point to a certain degree of environmental selection on these two ecotypes that have led to their niche specialization.

  17. Geographic Distribution of Archaeal Ammonia Oxidizing Ecotypes in the Atlantic Ocean

    PubMed Central

    Sintes, Eva; De Corte, Daniele; Haberleitner, Elisabeth; Herndl, Gerhard J.

    2016-01-01

    In marine ecosystems, Thaumarchaeota are most likely the major ammonia oxidizers. While ammonia concentrations vary by about two orders of magnitude in the oceanic water column, archaeal ammonia oxidizers (AOA) vary by only one order of magnitude from surface to bathypelagic waters. Thus, the question arises whether the key enzyme responsible for ammonia oxidation, ammonia monooxygenase (amo), exhibits different affinities to ammonia along the oceanic water column and consequently, whether there are different ecotypes of AOA present in the oceanic water column. We determined the abundance and phylogeny of AOA based on their amoA gene. Two ecotypes of AOA exhibited a distribution pattern reflecting the reported availability of ammonia and the physico-chemical conditions throughout the Atlantic, and from epi- to bathypelagic waters. The distinction between these two ecotypes was not only detectable at the nucleotide level. Consistent changes were also detected at the amino acid level. These changes include substitutions of polar to hydrophobic amino acid, and glycine substitutions that could have an effect on the configuration of the amo protein and thus, on its activity. Although we cannot identify the specific effect, the ratio of non-synonymous to synonymous substitutions (dN/dS) between the two ecotypes indicates a strong positive selection between them. Consequently, our results point to a certain degree of environmental selection on these two ecotypes that have led to their niche specialization. PMID:26903961

  18. [Temporal and spatial distribution of anthropogenic ammonia emissions in China: 1994-2006].

    PubMed

    Dong, Wen-xuan; Xing, Jia; Wang, Shu-xiao

    2010-07-01

    Ammonia has both direct and indirect impacts on important environmental issues including acid deposition, regional fine particles and eutrophication. Estimation of anthropogenic ammonia emissions will provide valuable information for the pollution control of acid deposition and regional fine particle. Based on the provincial activity data on N-fertilizer application, livestock farming, N-fertilizer production and populations, this paper uses emission factor method to estimate China's atmospheric ammonia emissions, analyzes its historical trends and presents its geographical distributions from year 1994 to 2006. The national total atmospheric ammonia emissions are estimated to be 11.06 million tons (Mt) in 1994, which increase quickly to 16.07 Mt in 2006. Emissions from livestock farming, N-fertilizer application, N-fertilizer production and human excreta have increased from 4.47 Mt, 5.94 Mt, 0.09 Mt, and 0.59 Mt in 1994 to 6.61 Mt, 8.68 Mt, 0.14 Mt, 0.65 Mt respectively in 2006. Livestock farming and N-fertilizer application are the most important ammonia emission sources, which contributed 40.79 and 55.53 percent of total emissions respectively in 2006. In 2006, the average ammonia emission intensity is 1.67 t x km(-2) but there are large variations among atmospheric ammonia emissions from each province. Emissions from provinces including Henan, Shandong, Hebei, Sichuan and Jiangsu accounted for 40.82 percent of national emissions. PMID:20825010

  19. Investigation of a chemiluminescent system for the determination of ammonia by flow-injection analysis

    SciTech Connect

    Kraus, P.R.; Crouch, S.R.

    1987-01-01

    A novel system for the determination of ammonia based on the chemiluminescent reaction between hypochlorite and luminol is presented. The technique of flow injection analysis was employed to automate the system. Ammonia reacts with hypochlorite to form monochloramine in basic solution which decreases the observed chemiluminescence intensity. Several interferents are identified, and the reasons why they interfere are discussed. The effects of interferents are minimized through the use of a double-tube dialyzer where the ammonia is diffused across the dialyzer membrane into a recipient stream of hydrochloric acid.

  20. A STUDY OF THE EFFECTS OF POST-COMBUSTION AMMONIA INJECTION ON FLY ASH QUALITY: CHARACTERIZATION OF AMMONIA RELEASE FROM CONCRETE AND MORTARS CONTAINING FLY ASH AS A POZZOLANIC ADMIXTURE

    SciTech Connect

    Robert F. Rathbone; Thomas L. Robl

    2001-04-11

    Work completed in this reporting period focused on finalization of the Work and Management Plan, sample acquisition and analysis, evaluation of ammonia measurement methods, and measurement of ammonia loss from mortar. All fly ash samples have been acquired and analyzed for chemical composition and particle fineness. Three non-ammoniated fly ash samples were obtained from power plants that do not inject ammonia for NOx or particulate control, while three ammoniated fly ashes originate from plants that inject ammonia into the flue gas. The fly ash sources were selected based on their marketability as concrete admixtures and ammonia content. Coarse and fine aggregates for mortar and concrete testing have also been secured and have been thoroughly characterized using ASTM methods. Methodologies for the measurement of ammonia in the gaseous and aqueous phase have been carefully considered in the context of their suitability for use in this project. These include ammonia detection tubes, carbon impregnated with sulfuric acid (CISA) tubes, titration, and electrochemical methods. It was concluded that each of these methods is potentially useful for different aspects of the project, depending on the phase and concentration of ammonia to be measured. Preparation of fly ash-containing mortars both with and without ammonia indicated that the ammonia has no significant influence on compressive strength. Finally, measurement of ammonia loss from mortar has begun and the results of several of these experiments are included herein. It has been found that, under the laboratory curing conditions devised, ammonia release from mortar occurs at a relatively rapid rate in the first 24 hours, proceeded by a much slower, essentially linear rate. Furthermore, at the end of the three-week experiments, it was calculated that greater than 80% of the initial ammonia concentration remained within the mortar.

  1. Priming ammonia lyases and aminomutases for industrial and therapeutic applications.

    PubMed

    Heberling, Matthew M; Wu, Bian; Bartsch, Sebastian; Janssen, Dick B

    2013-04-01

    Ammonia lyases (AL) and aminomutases (AM) are emerging in green synthetic routes to chiral amines and an AL is being explored as an enzyme therapeutic for treating phenylketonuria and cancer. Although the restricted substrate range of the wild-type enzymes limits their widespread application, the non-reliance on external cofactors and direct functionalization of an olefinic bond make ammonia lyases attractive biocatalysts for use in the synthesis of natural and non-natural amino acids, including β-amino acids. The approach of combining structure-guided enzyme engineering with efficient mutant library screening has extended the synthetic scope of these enzymes in recent years and has resolved important mechanistic issues for AMs and ALs, including those containing the MIO (4-methylideneimidazole-5-one) internal cofactor.

  2. Rh protein expression in branchial neuroepithelial cells, and the role of ammonia in ventilatory control in fish.

    PubMed

    Zhang, Li; Michele Nawata, C; De Boeck, Gudrun; Wood, Chris M

    2015-08-01

    Bill Milsom has made seminal contributions to our understanding of ventilatory control in a wide range of vertebrates. Teleosts are particularly interesting, because they produce a 3rd, potentially toxic respiratory gas (ammonia) in large amounts. Fish are well known to hyperventilate under high environmental ammonia (HEA), but only recently has the potential role of ammonia in normal ventilatory control been investigated. It is now clear that ammonia can act directly as a ventilatory stimulant in trout, independent of its effects on acid-base balance. Even in ureotelic dogfish sharks, acute elevations in ammonia cause increases in ventilation. Peripherally, the detection of elevated ammonia resides in gill arches I and II in trout, and in vitro, neuroepithelial cells (NECs) from these arches are sensitive to ammonia, responding with elevations in intracellular Ca(2+) ([Ca(2+)]i). Centrally, hyperventilatory responses to ammonia correlate more closely with concentrations of ammonia in the brain than in plasma or CSF. After chronic HEA exposure, ventilatory responsiveness to ammonia is lost, associated with both an attenuation of the [Ca(2+)]i response in NECs, and the absence of elevation in brain ammonia concentration. Chronic exposure to HEA also causes increases in the mRNA expression of several Rh proteins (ammonia-conductive channels) in both brain and gills. "Single cell" PCR techniques have been used to isolate the individual responses of NECs versus other gill cell types. We suggest several circumstances (post-feeding, post-exercise) where the role of ammonia as a ventilatory stimulant may have adaptive benefits for O2 uptake in fish.

  3. Effect of acetylene and ammonia as reburn fuel additions to methane in nitric oxide reburning

    SciTech Connect

    Kumpaty, S.K.; Nokku, V.P.; Subramanian, K.

    1996-12-31

    Presented in this paper are the computational results of NO reburning with (a) a combination of methane and acetylene and (b) a combination of methane and ammonia. An updated reaction mechanism that was more comprehensive in terms of predicting the ammonia and isocyanic acid oxidation chemistry was employed to run the CKINTERP program. Using the binary file created by executing the above program and the input stoichiometric ratio conditions, the CHEMKIN package predicted the exit concentrations of various species involved in NO reburning.

  4. Inhibition of ammonia monooxygenase in Nitrosomonas europaea by carbon disulfide.

    PubMed Central

    Hyman, M R; Kim, C Y; Arp, D J

    1990-01-01

    Carbon disulfide has long been recognized as a potent inhibitor of nitrification, and it is the likely active component in several nitrification inhibitors suitable for field use. The effects of this compound on Nitrosomonas europaea have been investigated, and the site of action has been determined. Low concentrations of CS2 (less than 400 microM) produced a time-dependent inhibition of ammonia-dependent O2 uptake but did not inhibit hydrazine-oxidizing activity. CS2 also produced distinct changes in difference spectra of whole cells. These results suggest that ammonia monooxygenase (AMO) is the site of action of CS2. Unlike the case for thiourea and acetylene, saturating concentrations of CS2 did not fully inhibit AMO, and the inhibition resulted in a low but significant rate of ammonia-dependent O2 uptake. The effects of CS2 were not competitive with respect to ammonia concentration, and the inhibition by CS2 did not require the turnover of AMO to take effect. The ability of CS2-treated cells to incorporate [14C]acetylene into the 28-kilodalton polypeptide of AMO was used to demonstrate that the effects of CS2 are compatible with a mode of action which involves a reduction of the rate of turnover of AMO without effects on the catalytic mechanism. It is proposed that CS2 may act on AMO by reversibly reacting with a suitable nucleophilic amino acid in close proximity to the active site copper. Images PMID:2118501

  5. A baseline study of atmospheric ammonia concentration and fluxes for forest

    NASA Astrophysics Data System (ADS)

    Hansen, K.; Boegh, E.; Hornsby, K. E.; Pryor, S. C.; Sørensen, L. L.

    2014-12-01

    Natural ammonia emissions are difficult to address because most measurement sites are influenced by nearby anthropogenic ammonia sources. Furthermore, measuring the net exchange of ammonia is challenging due to bi-directionality of the flux and the high reactivity of ammonia. In this study we present two months of half-hourly ammonia fluxes and concentrations measured above the remote forest site Morgan-Monroe State Forest (MMSF) in the central Midwest in USA. Measurements are conducted during the late summer and autumn 2013 using the Relaxed Eddy Accumulation Method with the purpose is to quantify the baseline concentration and exchange of ammonia in a natural forest ecosystem and to understand the controlling processes. Combined with additional ammonia studies for MMSF a seasonal baseline of the ammonia concentration above the forest of spring = 0.39±0.39, summer = 0.30±0.39, autumn = 0.20±0.26, and winter = 0.26±0.1 μg m-3 was concluded. The mean concentration of ammonia measured in this study was 0.23 μg m-3 but shorter periods with concentration higher than 1 μg m-3 were also seen. The fluxes were mainly upward (emission) of up to 0.11 μg m-2 s-1, however, when the atmospheric concentration was higher, downward fluxes (deposition) up to -0.07 μg m-2 s-1 occurred. Air mass back trajectories from the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model did not identify any specific source area causing the higher ammonia concentrations measured affirming that the atmospheric ammonia is surface controlled. The largest fluxes was found shortly after rain events indication that the humidity of the forest ecosystem in crucial in controlling both deposition and emission of atmospheric ammonia. Measurements of size resolved aerosol concentrations and nitric acid gas concentrations and fluxes indicated that gas-particle phase partitioning occurred and influenced the exchange of ammonia. At last, a clear diurnal pattern in the ammonia

  6. Superionic water-ammonia mixtures

    NASA Astrophysics Data System (ADS)

    Bethkenhagen, M.; Cebulla, D.; Redmer, R.; Hamel, S.

    2014-12-01

    The interior of the Giant Planets Uranus and Neptune contains large amounts of water, ammonia and methane (referred to as planetary ices). Many observable properties of these planets, such as luminosity, gravitational moments and magnetic fields, are thought to be determined by the physical and chemical properties of matter within this ice layer. Hence, the phase diagrams, equations of state and structural properties of these materials and their respective mixtures are of great interest.Especially the phase diagrams of water and ammonia gained much attention since Cavazzoni et al. [1] proposed superionic phases for these materials, which are characterized by highly mobile hydrogen ions in a lattice of oxygen and nitrogen ions, respectively. For water, the influence of such a phase on the properties of the Giant Planets as well as on exoplanets has been discussed widely. [2,3] Nevertheless, it is an open question how the properties of such a water layer change when another compound, e.g., ammonia is introduced. Considering a 1:1 mixture, we have performed ab initio simulations based on density functional theory using the VASP code [4] heating up structures which we had found from evolutionary random structure search calculations with XtalOpt [5]. We propose possible superionic water-ammonia structures present up to several Mbar. Moreover, we investigate the equation of state and transport properties of this mixture such as diffusion coefficients in order to compare with the pure compounds. These results are essential to construct new interior models for Neptune-like planets.[1] C. Cavazzoni et al., Science 283, 44 (1999).[2] R. Redmer et al., Icarus 211, 798 (2011).[3] L. Zeng and D. Sasselov, ApJ 784, 96 (2014).[4] G. Kresse and J. Hafner, Phys. Rev. B 47, 558 (1993).[5] D. C. Lonie and E. Zurek, Comput. Phys. Commun. 182, 372 (2011).

  7. Lyα-induced charge effects of polycyclic aromatic hydrocarbons embedded in ammonia and ammonia:water ice

    NASA Astrophysics Data System (ADS)

    Cuylle, Steven H.; Tenenbaum, Emily D.; Bouwman, Jordy; Linnartz, Harold; Allamandola, Louis J.

    2012-06-01

    Infrared emission features assigned to gas phase polycyclic aromatic hydrocarbons (PAHs) are observed in space along many lines of sight. In regions where interstellar ices are present, these emissions are largely quenched. It is here that PAHs form agglomerates covered by ice or freeze out on to dust grains, together with volatile species such as H2O, CO, CO2 and NH3. Upon exposure to the Lyα-dominated interstellar radiation field, PAHs are expected to participate in photo-induced chemical reactions, explicitly also involving the surrounding ice matrix. In this paper, a systematic laboratory-based study is presented for the solid-state behaviour of the PAHs pyrene and benzo[ghi]perylene upon Lyα irradiation in ammonia and mixed NH3:H2O astronomical ice analogues. The results are compared to recently published work focusing on a pure water ice environment. It is found that the ice matrix acts as an ‘electronic solid-state switch’ in which the relative amount of water and ammonia determines whether positively or negatively charged PAHs form. In pure water ice, cations are generated through direct ionization, whereas in pure ammonia ice, anions form through electron donation from ammonia-related photoproducts. The solid-state process controlling this latter channel involves electron transfer, rather than acid-base type proton transfer. In the mixed ice, the resulting products depend on the mixing ratio. The astronomical consequences of these laboratory findings are discussed.

  8. Heterogeneous uptake of amines by citric acid and humic acid.

    PubMed

    Liu, Yongchun; Ma, Qingxin; He, Hong

    2012-10-16

    Heterogeneous uptake of methylamine (MA), dimethylamine (DMA), and trimethylamine (TMA) onto citric acid and humic acid was investigated using a Knudsen cell reactor coupled to a quadrupole mass spectrometer at 298 K. Acid-base reactions between amines and carboxylic acids were confirmed. The observed uptake coefficients of MA, DMA, and TMA on citric acid at 298 K were measured to be 7.31 ± 1.13 × 10(-3), 6.65 ± 0.49 × 10(-3), and 5.82 ± 0.68 × 10(-3), respectively, and showed independence of sample mass. The observed uptake coefficients of MA, DMA, and TMA on humic acid at 298 K increased linearly with sample mass, and the true uptake coefficients of MA, DMA, and TMA were measured to be 1.26 ± 0.07 × 10(-5), 7.33 ± 0.40 × 10(-6), and 4.75 ± 0.15 × 10(-6), respectively. Citric acid, having stronger acidity, showed a higher reactivity than humic acid for a given amine; while the steric effect of amines was found to govern the reactivity between amines and citric acid or humic acid.

  9. Fluorographene based Ultrasensitive Ammonia Sensor

    PubMed Central

    Tadi, Kiran Kumar; Pal, Shubhadeep; Narayanan, Tharangattu N.

    2016-01-01

    Single molecule detection using graphene can be brought by tuning the interactions via specific dopants. Electrostatic interaction between the most electronegative element fluorine (F) and hydrogen (H) is one of the strong interactions in hydrogen bonding, and here we report the selective binding of ammonia/ammonium with F in fluorographene (FG) resulting to a change in the impedance of the system. Very low limit of detection value of ~0.44 pM with linearity over wide range of concentrations (1 pM–0.1 μM) is achieved using the FG based impedance sensor, andthisscreen printed FG sensor works in both ionized (ammonium) and un-ionized ammonia sensing platforms. The interaction energies of FG and NH3/NH4+ are evaluated using density functional theory calculations and the interactions are mapped. Here FGs with two different amounts of fluorinecontents −~5 atomic% (C39H16F2) and ~24 atomic% (C39H16F12) - are theoretically and experimentally studied for selective, high sensitive and ultra-low level detection of ammonia. Fast responding, high sensitive, large area patternable FG based sensor platform demonstrated here can open new avenues for the development of point-of-care devices and clinical sensors. PMID:27142522

  10. Planar waveguide sensor of ammonia

    NASA Astrophysics Data System (ADS)

    Rogoziński, Roman; Tyszkiewicz, Cuma; Karasiński, Paweł; Izydorczyk, Weronika

    2015-12-01

    The paper presents the concept of forming ammonia sensor based on a planar waveguide structure. It is an amplitude sensor produced on the basis of the multimode waveguide. The technological base for this kind of structure is the ion exchange method and the sol-gel method. The planar multimode waveguide of channel type is produced in glass substrate (soda-lime glass of Menzel-Glaser company) by the selective Ag+↔Na+ ion exchange. On the surface of the glass substrate a porous (~40%) silica layer is produced by the sol-gel method. This layer is sensitized to the presence of ammonia in the surrounding atmosphere by impregnation with Bromocresol Purple (BCP) dye. Therefore it constitutes a sensor layer. Spectrophotometric tests carried out showed about 50% reduction of cross-transmission changes of such sensor layer for a wave λ=593 nm caused by the presence of 25% ammonia water vapor in its ambience. The radiation source used in this type of sensor structure is a light emitting diode LED. The gradient channel waveguide is designed for frontal connection (optical glue) with a standard multimode telecommunications waveguide 62.5/125μm.

  11. Fiber-Optic Ammonia Sensors

    NASA Technical Reports Server (NTRS)

    Carter, Michael T.

    2003-01-01

    Reversible, colorimetric fiber-optic sensors are undergoing development for use in measuring concentrations of ammonia in air at levels relevant to human health [0 to 50 parts per million (ppm)]. A sensor of this type includes an optical fiber that has been modified by replacing a portion of its cladding with a polymer coat that contains a dye that reacts reversibly with ammonia and changes color when it does so. The change in color is measured as a change in the amount of light transmitted from one end of the fiber to the other. Responses are reversible and proportional to the concentration of ammonia over the range from 9 to 175 ppm and in some cases the range of reversibility extends up to 270 ppm. The characteristic time for the response of a sensor to rise from 10 to 90 percent of full scale is about 25 seconds. These sensors are fully operational in pure carbon dioxide and are not adversely affected by humidity. This work was done by Michael T. Carter

  12. Physiological and molecular responses of the goldfish (Carassius auratus) kidney to metabolic acidosis, and potential mechanisms of renal ammonia transport.

    PubMed

    Lawrence, Michael J; Wright, Patricia A; Wood, Chris M

    2015-07-01

    Relative to the gills, the mechanisms by which the kidney contributes to ammonia and acid-base homeostasis in fish are poorly understood. Goldfish were exposed to a low pH environment (pH 4.0, 48 h), which induced a characteristic metabolic acidosis and an increase in total plasma [ammonia] but reduced plasma ammonia partial pressure (PNH3). In the kidney tissue, total ammonia, lactate and intracellular pH remained unchanged. The urinary excretion rate of net base under control conditions changed to net acid excretion under low pH, with contributions from both the NH4 (+) (∼30%) and titratable acidity minus bicarbonate (∼70%; TA-HCO3 (-)) components. Inorganic phosphate (Pi), urea and Na(+) excretion rates were also elevated while Cl(-) excretion rates were unchanged. Renal alanine aminotransferase activity increased under acidosis. The increase in renal ammonia excretion was due to significant increases in both the glomerular filtration and the tubular secretion rates of ammonia, with the latter accounting for ∼75% of the increase. There was also a 3.5-fold increase in the mRNA expression of renal Rhcg-b (Rhcg1) mRNA. There was no relationship between ammonia secretion and Na(+) reabsorption. These data indicate that increased renal ammonia secretion during acidosis is probably mediated through Rhesus (Rh) glycoproteins and occurs independently of Na(+) transport, in contrast to branchial and epidermal models of Na(+)-dependent ammonia transport in freshwater fish. Rather, we propose a model of parallel H(+)/NH3 transport as the primary mechanism of renal tubular ammonia secretion that is dependent on renal amino acid catabolism.

  13. Inactivation of Ascaris suum eggs by ammonia.

    PubMed

    Pecson, Brian M; Nelson, Kara L

    2005-10-15

    Uncharged ammonia is known to cause inactivation of a number of wastewater pathogens, but its effect on Ascaris eggs has never been isolated or quantified. The objectives of this research were to determine the conditions under which ammonia inactivates eggs of the swine Ascaris species, Ascaris suum, and to quantify the impact of ammonia on the U.S. EPA's requirements for alkaline treatment to produce Class A sludge. Eggs were incubated in controlled, laboratory solutions such that the effects of ammonia concentration and speciation, pH, and temperature could be separated. With a 24-h incubation, the inactivation at all pH levels (range 7-11) was not statistically different in the absence of ammonia. The presence of ammonia (0-1000 ppm as N) significantly increased Ascaris egg inactivation at pH 9 and 11, and the ovicidal effect was directly related to the concentration of the uncharged NH3 species. Increasing temperatures (32-52 degrees C) caused increased inactivation at all pH levels and ammonia concentrations. The current EPA treatment requirements to produce Class A biosolids by alkaline treatment have temperature, pH, and time requirements, but do not account for the effectof differences in ammonia concentration on inactivation. To illustrate the potential savings in temperature and pH that could be achieved when accounting for ammonia inactivation, the combinations of ammonia concentration, temperature, and pH neededto achieve 99% inactivation after 72 h were determined. The presence of ammonia at concentrations encountered in sludges and feces (up to 8000 ppm as N) allowed for 99% egg inactivation to be achieved at temperatures up to 14 degrees C lower than ammonia-free controls. Thus, environmentally relevant concentrations of ammonia may significantly increase the rate of Ascaris egg inactivation during alkaline stabilization.

  14. Urea and Ammonia Metabolism and the Control of Renal Nitrogen Excretion.

    PubMed

    Weiner, I David; Mitch, William E; Sands, Jeff M

    2015-08-01

    Renal nitrogen metabolism primarily involves urea and ammonia metabolism, and is essential to normal health. Urea is the largest circulating pool of nitrogen, excluding nitrogen in circulating proteins, and its production changes in parallel to the degradation of dietary and endogenous proteins. In addition to serving as a way to excrete nitrogen, urea transport, mediated through specific urea transport proteins, mediates a central role in the urine concentrating mechanism. Renal ammonia excretion, although often considered only in the context of acid-base homeostasis, accounts for approximately 10% of total renal nitrogen excretion under basal conditions, but can increase substantially in a variety of clinical conditions. Because renal ammonia metabolism requires intrarenal ammoniagenesis from glutamine, changes in factors regulating renal ammonia metabolism can have important effects on glutamine in addition to nitrogen balance. This review covers aspects of protein metabolism and the control of the two major molecules involved in renal nitrogen excretion: urea and ammonia. Both urea and ammonia transport can be altered by glucocorticoids and hypokalemia, two conditions that also affect protein metabolism. Clinical conditions associated with altered urine concentrating ability or water homeostasis can result in changes in urea excretion and urea transporters. Clinical conditions associated with altered ammonia excretion can have important effects on nitrogen balance.

  15. Ammonia Regulation of Carbon Metabolism in Photosynthesizing Leaf Discs 1

    PubMed Central

    Platt, Steven G.; Plaut, Zvi; Bassham, James A.

    1977-01-01

    Alfalfa (Medicago sativa L., var. El Unico) leaf discs, floating on buffer containing NH4Cl and photosynthesizing with 14CO2, produced more labeled amino acid and less sucrose than did control discs (no added NH4Cl). The level of pyruvate increased and that of phosphoenolpyruvate decreased. These and other changes in levels of labeled compounds led us to conclude that pyruvate kinase was activated by ammonia, resulting in increased transfer of photosynthetically incorporated carbon to synthesis of amino acid skeletons at the expense of sucrose synthesis. Carbon flow through enzymes catalyzing the anaplerotic reactions was apparently stimulated. PMID:16660175

  16. Ammonia Process by Pressure Swing Adsorption

    SciTech Connect

    Dr Felix Jegede

    2010-12-27

    The overall objective of the project is to design, develop and demonstrate a technically feasible and commercially viable system to produce ammonia along with recovery of the products by adsorption separation methods and significantly decrease the energy requirement in ammonia production. This is achieved through a significantly more efficient ammonia psa recovery system. The new ammonia recovery system receives the reactor effluents and achieves complete ammonia recovery, (which completely eliminates the energy intensive refrigeration and condensation system currently used in ammonia production). It also recovers the unused reactants and recycles them back to the reactor, free of potential reactor contaminants, and without the need for re-compression and re-heat of recycle stream thereby further saving more energy. The result is a significantly lower energy consumption, along with capital cost savings.

  17. The Importance of Ammonia for Winter Haze Formation in Two Oil and Gas Production Regions

    NASA Astrophysics Data System (ADS)

    Collett, J. L., Jr.; Li, Y.; Evanoski-Cole, A. R.; Sullivan, A.; Day, D.; Archuleta, C.; Tigges, M.; Sewell, H. J.; Prenni, A. J.; Schichtel, B. A.

    2014-12-01

    Fine particle ammonium nitrate formation results from the atmospheric reaction of gaseous ammonia and nitric acid. This reaction is most important in winter when low temperatures thermodynamically enhance particle formation. Nitrogen oxides emissions from oil and gas operations partially react in the atmosphere to form nitric acid. The availability of atmospheric ammonia plays an important role in determining whether the nitric acid formed results in wintertime ammonium nitrate formation. Here we contrast situations in two important U.S. oil and gas production regions. Measurements of ammonia, nitric acid, ammonium nitrate and other species were made from 2007 to present near Boulder, Wyoming and in winters 2013 and 2014 in western North Dakota. The Boulder, Wyoming site is close to the large Jonah and Pinedale Anticline gas fields. Field sites at the north unit of Theodore Roosevelt National Park and Fort Union are situated in the large Bakken Formation oil and gas production region. Wintertime formation of nitric acid and ammonium nitrate, together comprising nitrogen in the +5 oxidation state (N(V)), was observed in both locations. Concentrations of N(V), however, are generally much lower at Boulder, WY than in the Bakken. An even bigger difference is seen in fine particle ammonium nitrate concentrations; limited regional ammonia is available in western Wyoming to react with nitric acid, leaving a portion of the nitric acid trapped in the gas phase. Higher concentrations of ammonia are observed in the Bakken where they support formation of much higher concentrations of ammonium nitrate. Comparison of these two regions clearly indicates the importance of understanding both local NOx emissions and regional concentrations of ammonia in predicting source impacts on formation of fine particles and haze.

  18. Adsorption of ammonia on multilayer iron phthalocyanine

    SciTech Connect

    Isvoranu, Cristina; Knudsen, Jan; Ataman, Evren; Andersen, Jesper N.; Schnadt, Joachim; Schulte, Karina; Wang Bin; Bocquet, Marie-Laure

    2011-03-21

    The adsorption of ammonia on multilayers of well-ordered, flat-lying iron phthalocyanine (FePc) molecules on a Au(111) support was investigated by x-ray photoelectron spectroscopy. We find that the electron-donating ammonia molecules coordinate to the metal centers of iron phthlalocyanine. The coordination of ammonia induces changes of the electronic structure of the iron phthalocyanine layer, which, in particular, lead to a modification of the FePc valence electron spin.

  19. Polyaniline-based optical ammonia detector

    DOEpatents

    Duan, Yixiang; Jin, Zhe; Su, Yongxuan

    2002-01-01

    Electronic absorption spectroscopy of a polyaniline film deposited on a polyethylene surface by chemical oxidation of aniline monomer at room temperature was used to quantitatively detect ammonia gas. The present optical ammonia gas detector was found to have a response time of less than 15 s, a regeneration time of less than 2 min. at room temperature, and a detection limit of 1 ppm (v/v) for ammonia, with a linear dynamic range from 180 ppm to 18,000 ppm.

  20. Comparison of damage to human hair fibers caused by monoethanolamine- and ammonia-based hair colorants.

    PubMed

    Bailey, Aaron D; Zhang, Guiru; Murphy, Bryan P

    2014-01-01

    The number of Level 3 hair color products that substitute 2-aminoethanol [monoethanolamine (MEA)] for ammonia is increasing. There is some anecdotal evidence that higher levels of MEA can be more damaging to hair and more irritating than a corresponding equivalent level of the typical alkalizer, ammonia (in the form of ammonium hydroxide). Our interest was to understand in more quantitative terms the relative hair damage from the two alkalizers, particularly at the upper limits of MEA on-head use. Limiting investigations of oxidative hair damage to increases in cysteic acid content (from cystine oxidation) can underreport the extent of total damage. Hence, we complemented Fourier transform infrared spectroscopy (FTIR) cysteic acid level measurement with scanning electron microscopy (SEM) photomicrographs to visualize cuticle damage, and protein loss to understand not only the oxidative damage but also the damage caused by other damage pathways, e.g., reaction of the more nucleophilic (than ammonia) MEA with hair protein. In fact, all methods show an increase in damage from MEA-based formulations, up to 85% versus ammonia in the most extreme case. Hence, if the odor of ammonia is a concern, a better approach may be to minimize the volatility of ammonia in specific chassis rather than replacing it with high levels of a potentially more damaging alkalizer such as MEA.

  1. Electrokinetic remediation of manganese and ammonia nitrogen from electrolytic manganese residue.

    PubMed

    Shu, Jiancheng; Liu, Renlong; Liu, Zuohua; Du, Jun; Tao, Changyuan

    2015-10-01

    Electrolytic manganese residue (EMR) is a solid waste found in filters after sulphuric acid leaching of manganese carbonate ore, which mainly contains manganese and ammonia nitrogen and seriously damages the ecological environment. This work demonstrated the use of electrokinetic (EK) remediation to remove ammonia nitrogen and manganese from EMR. The transport behavior of manganese and ammonia nitrogen from EMR during electrokinetics, Mn fractionation before and after EK treatment, the relationship between Mn fractionation and transport behavior, as well as the effects of electrolyte and pretreatment solutions on removal efficiency and energy consumption were investigated. The results indicated that the use of H2SO4 and Na2SO4 as electrolytes and pretreatment of EMR with citric acid and KCl can reduce energy consumption, and the removal efficiencies of manganese and ammonia nitrogen were 27.5 and 94.1 %, respectively. In these systems, electromigration and electroosmosis were the main mechanisms of manganese and ammonia nitrogen transport. Moreover, ammonia nitrogen in EMR reached the regulated level, and the concentration of manganese in EMR could be reduced from 455 to 37 mg/L. In general, the electrokinetic remediation of EMR is a promising technology in the future.

  2. Ammonia toxicity as a criterion for the evaluation of larval quality in the prawn Macrobrachium rosenbergii.

    PubMed

    Cavalli, R O; Berghe, E V; Lavens, P; Nguyen, T T; Wille, M; Sorgeloos, P

    2000-03-01

    The feasibility of a short-term ammonia toxicity test as an evaluation criterion for larval quality was assessed in three trials. In each one, Macrobrachium rosenbergii larvae originating from the same spawn were nutritionally differentiated in two groups by feeding them either a nutrient-rich (Artemia nauplii enriched for 24 h with n-3 highly unsaturated fatty acids (HUFA) and ascorbic acid (AA)) or a nutrient-poor diet (Artemia nauplii starved for 24 h). Throughout their development, larvae from both treatments were exposed during 24 h to six concentrations of total ammonia (NH(4)(+)+NH(3)) and a control (no ammonia added). Based on mortality rates, the median lethal concentration for 50% of the population (LC(50)) was estimated. As expected from earlier work, larvae fed the optimal diet presented higher n-3 HUFA and AA contents as well as higher growth and metamorphosis rates. From the moment the effect of diet quality was analytically detectable in the tissues of the larvae, the ammonia test was able to distinguish both groups of larvae. Differences in ammonia tolerance were observed as early as larval stage 4 and remained evident throughout larval development. The short-term ammonia toxicity test proved to be a valuable, sensitive and reproducible criterion for the establishment of larval quality. PMID:11790354

  3. Electrokinetic remediation of manganese and ammonia nitrogen from electrolytic manganese residue.

    PubMed

    Shu, Jiancheng; Liu, Renlong; Liu, Zuohua; Du, Jun; Tao, Changyuan

    2015-10-01

    Electrolytic manganese residue (EMR) is a solid waste found in filters after sulphuric acid leaching of manganese carbonate ore, which mainly contains manganese and ammonia nitrogen and seriously damages the ecological environment. This work demonstrated the use of electrokinetic (EK) remediation to remove ammonia nitrogen and manganese from EMR. The transport behavior of manganese and ammonia nitrogen from EMR during electrokinetics, Mn fractionation before and after EK treatment, the relationship between Mn fractionation and transport behavior, as well as the effects of electrolyte and pretreatment solutions on removal efficiency and energy consumption were investigated. The results indicated that the use of H2SO4 and Na2SO4 as electrolytes and pretreatment of EMR with citric acid and KCl can reduce energy consumption, and the removal efficiencies of manganese and ammonia nitrogen were 27.5 and 94.1 %, respectively. In these systems, electromigration and electroosmosis were the main mechanisms of manganese and ammonia nitrogen transport. Moreover, ammonia nitrogen in EMR reached the regulated level, and the concentration of manganese in EMR could be reduced from 455 to 37 mg/L. In general, the electrokinetic remediation of EMR is a promising technology in the future. PMID:26062467

  4. A Possible Role of Divalent Manganese Ions in the Photoinduction of Phenylalanine Ammonia-Lyase

    PubMed Central

    Engelsma, G.

    1972-01-01

    Divalent Mn ions cause an increase in the level of phenylalanine ammonia-lyase in gherkin hypocotyls. With the exception of Mg ions, which had a small effect, no other metal ion has so far been found which could replace the Mn ion in this respect. Invertase and peroxidase were not significantly affected by the Mn treatment. The increase in phenylalanine ammonialyase activity is explained by the removal, under the influence of Mn ions, of hydroxycinnamic acids, which cause repression of phenylalanine ammonia-lyase synthesis and/or inactivation of phenylalanine ammonia-lyase. Arguments are advanced for the hypothesis that photochemical transformations of Mn complexes are involved in the photoinduction of phenylalanine ammonia-lyase in dark-grown gherkin seedlings. PMID:16658225

  5. Adsorption study of Ammonia Nitrogen by watermelon rind

    NASA Astrophysics Data System (ADS)

    Ibrahim, A.; Yusof, L.; Beddu, N. S.; Galasin, N.; Lee, P. Y.; Lee, R. N. S.; Zahrim, A. Y.

    2016-06-01

    The utilization of fruit waste for low-cost adsorbents as a replacement for costly conventional methods of removing ammonia nitrogen from wastewater has been reviewed. The adsorption studies were conducted as a function of contact time and adsorbent dosage and it were carried out on four different adsorbents; fresh watermelon rind and modified watermelon rind with sodium hydroxide (NaOH), potassium hydroxide (KOH) and sulphuric acid (H2SO4). Adsorbents were tested for characterization by using zeta potential test and all samples shows negative values thus makes it favourable for the adsorption process. The batch experimental result showed that adsorption process is rapid and equilibrium was established within 40 minutes of contact time. The ammonia nitrogen removal rate amounted in range of 96% to 99%, and the adsorption capacities were in range of 1.21 to 1.24 mg/g for all four different types of adsorbents used.

  6. Adsorption of ammonia on vanadium-antimony mixed oxides

    NASA Astrophysics Data System (ADS)

    Seitz, Hernan; Germán, Estefanía; Juan, Alfredo; Irigoyen, Beatriz

    2012-02-01

    We analyzed the adsorption of ammonia (NH3) on the VSbO4(1 1 0) catalyst surface using density functional theory (DFT) calculations. We followed the evolution of the chemical bonds between different atoms of the resulting NH3/VSbO4 system and the changes in the electronic structure of the catalyst. NH3 preferential adsorption geometries were analyzed through the crystal orbital overlap population (COOP) concept and the density of states (DOS) curves. The VSbO4(1 1 0) surface exhibits Lewis and Brønsted acid sites on which the ammonia molecule can interact. On the Lewis acid site, NH3 adsorption resulted in the interaction between the N and a surface V-isolated cation. On Brønsted acid site, N interacted with a surface H coming from the chemical dissociation of water. The COOP analysis indicate that NH3 interaction on the VSbO4(1 1 0) surface is weak. In addition, the DOS curves show more developed electronic interactions for NH3 adsorption on Lewis acid site than over Brønsted acid site.

  7. On the reactive adsorption of ammonia on activated carbons modified by impregnation with inorganic compounds.

    PubMed

    Bandosz, Teresa J; Petit, Camille

    2009-10-15

    Ammonia adsorption was studied under dynamic conditions, at room temperature, on activated carbons of different origins (coal-based, wood-based and coconut-shell-based carbons) before and after their impregnation with various inorganic compounds including metal chlorides, metal oxides and polycations. The role of humidity was evaluated by running tests in both dry and moist conditions. Adsorbents were analyzed before and after exposure to ammonia by thermal analyses, sorption of nitrogen, potentiometric titration, X-ray diffraction and FTIR spectroscopy. Results of breakthrough tests show significant differences in terms of adsorption capacity depending on the parent carbon, the impregnates and the experimental conditions. It is found that surface chemistry governs ammonia adsorption on the impregnated carbons. More precisely, it was demonstrated that a proper combination of the surface pH, the strength, type and amount of functional groups present on the adsorbents' surface is a key point in ammonia uptake. Water can have either positive or negative effects on the performance of adsorbents. It can enhance NH(3) adsorption capacity since it favors ammonia dissolution and thus enables reaction between ammonium ions and carboxylic groups from the carbons' surface. On the other hand, water can also reduce the performance from the strength of adsorption standpoint. It promotes dissolution of ammonia and that ammonia is first removed from the system when the adsorbent bed is purged with air. Ammonia, besides adsorption by van der Waals forces and dissolution in water, is also retained on the surface via reactive mechanisms such as acid-base reactions (Brønsted and Lewis) or complexation. Depending on the materials used and the experimental conditions, 6-47% ammonia adsorbed is strongly retained on the surface even when the bed is purged with air. PMID:19615690

  8. Discontinuous ammonia excretion and glutamine storage in littoral Oniscidea (Crustacea: Isopoda): testing tidal and circadian models.

    PubMed

    Nakamura, Maya; Wright, Jonathan C

    2013-01-01

    A key evolutionary development facilitating land colonization in terrestrial isopods (Isopoda: Oniscidea) is the intermittent liberation of waste nitrogen as volatile ammonia. Intermittent ammonia release exploits glutamine (Gln) as an intermediary nitrogen store. Here, we explore the relationship between temporal patterns of ammonia release and Gln accumulation in three littoral oniscideans from Southern California. Results are interpreted in terms of water availability, habitat, activity patterns, and ancestry. A two-way experimental design was used to test whether ammonia excretion and Gln accumulation follow a tidal or diel periodicity. Ammonia excretion was studied in the laboratory using chambers with or without available seawater and using an acid trap to collect volatile ammonia. Ligia occidentalis releases ammonia directly into seawater and accumulates Gln during low tide (48.9 ± 6.5 μmol g⁻¹ at low tide, 24.1 ± 3.0 μmol g⁻¹ at high tide), indicating that excretion is tidally constrained. Alloniscus perconvexus and Tylos punctatus can excrete ammonia directly into seawater or utilize volatilization. Both species burrow in sand by day and show a diel excretory pattern, accumulating Gln nocturnally (31.8 ± 2.7 μmol g⁻¹ at dawn and 21.8 ± 2.3 μmol g⁻¹ at dusk for A. perconvexus; 85.7 ± 15.1 μmol g⁻¹ at dawn and 25.4 ± 2.9 μmol g⁻¹ at dusk for T. punctatus) and liberating ammonia diurnally. Glutaminase shows higher activity in terrestrial (0.54-0.86 U g⁻¹) compared to intertidal (0.25-0.31 U g⁻¹) species, consistent with the need to generate high PNH₃ for volatilization. The predominant isoform in Armadillidium vulgare is phosphate dependent and maleate independent; phosphate is a plausible regulator in vivo. PMID:22836297

  9. On the reactive adsorption of ammonia on activated carbons modified by impregnation with inorganic compounds

    SciTech Connect

    Bandosz, T.J.; Petit, C.

    2009-10-15

    Ammonia adsorption was studied under dynamic conditions, at room temperature, on activated carbons of different origins (coal-based, wood-based and coconut-shell-based carbons) before and after their impregnation with various inorganic compounds including metal chlorides, metal oxides and polycations. The role of humidity was evaluated by running tests in both dry and moist conditions. Adsorbents were analyzed before and after exposure to ammonia by thermal analyses, sorption of nitrogen, potentiometric titration, X-ray diffraction and FTIR spectroscopy. Results of breakthrough tests show significant differences in terms of adsorption capacity depending on the parent carbon, the impregnates and the experimental conditions. It is found that surface chemistry governs ammonia adsorption on the impregnated carbons. More precisely, it was demonstrated that a proper combination of the surface pH, the strength, type and amount of functional groups present on the adsorbents' surface is a key point in ammonia uptake. Water can have either positive or negative effects on the performance of adsorbents. It can enhance NH{sub 3} adsorption capacity since it favors ammonia dissolution and thus enables reaction between ammonium ions and carboxylic groups from the carbons' surface. On the other hand, water can also reduce the performance from the strength of adsorption standpoint. It promotes dissolution of ammonia and that ammonia is first removed from the system when the adsorbent bed is purged with air. Ammonia, besides adsorption by van der Waals forces and dissolution in water, is also retained on the surface via reactive mechanisms such as acid-base reactions (Bronsted and Lewis) or complexation. Depending on the materials used and the experimental conditions, 6-47% ammonia adsorbed is strongly retained on the surface even when the bed is purged with air.

  10. Discontinuous ammonia excretion and glutamine storage in littoral Oniscidea (Crustacea: Isopoda): testing tidal and circadian models.

    PubMed

    Nakamura, Maya; Wright, Jonathan C

    2013-01-01

    A key evolutionary development facilitating land colonization in terrestrial isopods (Isopoda: Oniscidea) is the intermittent liberation of waste nitrogen as volatile ammonia. Intermittent ammonia release exploits glutamine (Gln) as an intermediary nitrogen store. Here, we explore the relationship between temporal patterns of ammonia release and Gln accumulation in three littoral oniscideans from Southern California. Results are interpreted in terms of water availability, habitat, activity patterns, and ancestry. A two-way experimental design was used to test whether ammonia excretion and Gln accumulation follow a tidal or diel periodicity. Ammonia excretion was studied in the laboratory using chambers with or without available seawater and using an acid trap to collect volatile ammonia. Ligia occidentalis releases ammonia directly into seawater and accumulates Gln during low tide (48.9 ± 6.5 μmol g⁻¹ at low tide, 24.1 ± 3.0 μmol g⁻¹ at high tide), indicating that excretion is tidally constrained. Alloniscus perconvexus and Tylos punctatus can excrete ammonia directly into seawater or utilize volatilization. Both species burrow in sand by day and show a diel excretory pattern, accumulating Gln nocturnally (31.8 ± 2.7 μmol g⁻¹ at dawn and 21.8 ± 2.3 μmol g⁻¹ at dusk for A. perconvexus; 85.7 ± 15.1 μmol g⁻¹ at dawn and 25.4 ± 2.9 μmol g⁻¹ at dusk for T. punctatus) and liberating ammonia diurnally. Glutaminase shows higher activity in terrestrial (0.54-0.86 U g⁻¹) compared to intertidal (0.25-0.31 U g⁻¹) species, consistent with the need to generate high PNH₃ for volatilization. The predominant isoform in Armadillidium vulgare is phosphate dependent and maleate independent; phosphate is a plausible regulator in vivo.

  11. Role of ammonia in the activiation of methanol dehydrogenase/cytochrome C(L) enzyme

    NASA Astrophysics Data System (ADS)

    Kunjumon, Ancy

    Recent advancement in enzyme catalysis has opened ways to design efficient biocatalysts, bio-sensors and bio-fuel cells. An in-depth knowledge about the mechanism of the reaction taking place within the enzymes is of great importance to achieve these goals. In this dissertation, various computation methods are applied to investigate the mechanism behind enzyme catalysis in the presence of compounds called activators. Methanol dehydrogenase (MDH) is a well-known bio-catalyst that can oxidize excess of methanol from the environment to formaldehyde. The enzyme works well within the bacterial environment, but under in vitro, it loses activity. Ammonia is used as an activator to restore the activity of MDH. The Monte Carlo search using simulated annealing metaheuristic method is conducted to explore the binding of MDH with its natural electron acceptor Cytochrome cL in varying concentration of ammonia. The main aim behind this is to explore the interaction energy between the enzymes under the influence of its activator. The concentration of ammonia is varied from 0 to 5 ammonia molecules. Moving deeper into the active site of MDH, molecular mechanics and dynamics calculations were performed to investigate the position and effect of ammonia in the active site amino acids of MDH. The concentration of ammonia was varied from 0 to 55.39 mM. It was proposed that ammonia may form a complex conjugate with the cofactor of MDH (Pyrroloquinoline quinone) to assist in the oxidation of methanol. Two of the most debated methanol oxidation mechanisms, Addition-Elimination reaction and Hydride-Transfer mechanism, were used to investigate the role of ammonia in the oxidation of methanol. Density functional theory (DFT) was applied to explore the methanol oxidation mechanism in the presence of ammonia. Models of varying size that best represent the active site of MDH were tested for this purpose. The interaction energy obtained after the docking of MDH and Cytochrome cL (CL) indicate

  12. Optical humidity and ammonia gas sensors using Reichardt's dye-polymer composites.

    PubMed

    Sadaoka, Y; Sakai, Y; Murata, Y U

    1992-12-01

    Optical intensity reflected at 750 nm by Reichardt's betain dye-polymer (PMMA or PEO) composite increased with an increase in humidity and was not affected by ammonia vapor. For the composites treated with hydrochloric acid, the intensity at around 590 nm decreased with an increase in ammonia concentration, and the sensitivity was enhanced by the presence of water vapor. The treatment with hydrochloric acid induced the formation of phenolic group, O(-)H(+) and N(+)Cl(-) in the dye. The sorption of NH(3) decreases the ionic interactions. PMID:18965589

  13. Ammonia and hydrogen sulfide removal using biochar

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Reducing ammonia and hydrogen sulfide emissions from livestock facilities is an important issue for many communities and livestock producers. Ammonia has been regarded as odorous, precursor for particulate matter (PM), and contributed to livestock mortality. Hydrogen sulfide is highly toxic at elev...

  14. Method for releasing hydrogen from ammonia borane

    SciTech Connect

    Varma, Arvind; Diwan, Moiz; Shafirovich, Evgeny; Hwang, Hyun-Tae; Al-Kukhun, Ahmad

    2013-02-19

    A method of releasing hydrogen from ammonia borane is disclosed. The method comprises heating an aqueous ammonia borane solution to between about 80-135.degree. C. at between about 14.7 and 200 pounds per square inch absolute (psia) to release hydrogen by hydrothermolysis.

  15. Ammonia Production Using Pressure Swing Adsorption

    SciTech Connect

    2009-02-01

    This factsheet describes a research project whose overall objective is to develop and demonstrate a technically feasible and commercially viable system that integrates reaction to produce ammonia along with recovery of the products by adsorption separation methods and significantly decrease the energy requirement in ammonia production.

  16. Decontaminating Aluminum/Ammonia Heat Pipes

    NASA Technical Reports Server (NTRS)

    Jones, J. A.

    1985-01-01

    Internal gas slugs reduced or eliminated. Manufacturing method increases efficiency of aluminum heat pipes in which ammonia is working fluid by insuring pipe filled with nearly pure charge of ammonia. In new process heat pipe initially closed with stainless-steel valve instead of weld so pipe put through several cycles of filling, purging, and accelerated aging.

  17. Regeneration of ammonia borane from polyborazylene

    DOEpatents

    Sutton, Andrew; Gordon, John C; Ott, Kevin C; Burrell, Anthony K

    2013-02-05

    Method of producing ammonia borane, comprising providing a reagent comprising a dehydrogenated material in a suitable solvent; and combining the reagent with a reducing agent comprising hydrazine, a hydrazine derivative, or combinations thereof, in a reaction which produces a mixture comprising ammonia borane.

  18. Ammonia Solubility in High Concentration Salt Solutions

    SciTech Connect

    HEDENGREN, D.C.

    2000-02-01

    Solubility data for ammonia in water and various dilute solutions are abundant in the literature. However, there is a noticeable lack of ammonia solubility data for high salt, basic solutions of various mixtures of salts including those found in many of the Hanford Washington underground waste tanks. As a result, models based on solubility data for dilute salt solutions have been used to extrapolate to high salt solutions. These significant extrapolations need to be checked against actual laboratory data. Some indirect vapor measurements have been made. A more direct approach is to determine the ratio of solubility of ammonia in water to its solubility in high salt solutions. In various experiments, pairs of solutions, one of which is water and the other a high salt solution, are allowed to come to equilibrium with a common ammonia vapor pressure. The ratio of concentrations of ammonia in the two solutions is equal to the ratio of the respective ammonia solubilities (Henry's Law constants) at a given temperature. This information can then be used to refine the models that predict vapor space compositions of ammonia. Ammonia at Hanford is of concern because of its toxicity in the environment and its contribution to the flammability of vapor space gas mixtures in waste tanks.

  19. Effects of conservation tillage practices on ammonia emissions from Loess Plateau rain-fed winter wheat fields

    NASA Astrophysics Data System (ADS)

    Yang, Yang; Zhou, Chunju; Li, Na; Han, Kun; Meng, Yuan; Tian, Xiaoxiao; Wang, Linquan

    2015-03-01

    Ammonia emissions from agricultural activities contribute to air pollution. For the rain-fed winter wheat system in the Loess Plateau there is a lack of information about ammonia emissions. Current study aimed to provide field data on ammonia emissions affected by conservation tillage practices and nitrogen applications. A two-year field experiment was conducted during 2011-2013 wheat growing seasons followed a split-plot design. Main plots consisted of one conventional tillage (CT, as the control) and five conservation tillage systems, i.e., stalk mulching (SM), film mulching (FM), ridge tillage (RT), ridge tillage with film mulch on the ridge (RTfm), and ridge tillage with film mulch on the ridge and stalk mulch in the furrow (RTfmsm); while subplots consisted of two nitrogen application rates, i.e., 0 and 180 kg N ha-1. Ammonia emissions were measured using an acid trapping method with vented chambers. Results showed ammonia fluxes peaked during the first 10 days after fertilization. On average, nitrogen application increased ammonia emissions by 26.5% (1.31 kg N ha-1) compared with treatments without nitrogen application (P < 0.05). Ammonia fluxes were strongly dependent on soil ammonium, moisture, and temperature. Tillage systems had significant effects on ammonia emissions. On average, conservation tillage practices reduced ammonia emissions by 7.7% (0.46 kg N ha-1) compared with conventional tillage (P < 0.05), with FM most effective. Deep-band application of nitrogen fertilizer, stalk mulches, and film mulches were responsible for reductions in ammonia emissions from nitrogen fertilization in conservation tillage systems, thus they were recommended to reduce ammonia emissions from winter wheat production regions in the southern Loess Plateau.

  20. Clinical utility of breath ammonia for evaluation of ammonia physiology in healthy and cirrhotic adults.

    PubMed

    Spacek, Lisa A; Mudalel, Matthew; Tittel, Frank; Risby, Terence H; Solga, Steven F

    2015-12-14

    Blood ammonia is routinely used in clinical settings to assess systemic ammonia in hepatic encephalopathy and urea cycle disorders. Despite its drawbacks, blood measurement is often used as a comparator in breath studies because it is a standard clinical test. We sought to evaluate sources of measurement error and potential clinical utility of breath ammonia compared to blood ammonia. We measured breath ammonia in real time by quartz enhanced photoacoustic spectrometry and blood ammonia in 10 healthy and 10 cirrhotic participants. Each participant contributed 5 breath samples and blood for ammonia measurement within 1 h. We calculated the coefficient of variation (CV) for 5 breath ammonia values, reported medians of healthy and cirrhotic participants, and used scatterplots to display breath and blood ammonia. For healthy participants, mean age was 22 years (±4), 70% were men, and body mass index (BMI) was 27 (±5). For cirrhotic participants, mean age was 61 years (±8), 60% were men, and BMI was 31 (±7). Median blood ammonia for healthy participants was within normal range, 10 μmol L(-1) (interquartile range (IQR), 3-18) versus 46 μmol L(-1) (IQR, 23-66) for cirrhotic participants. Median breath ammonia was 379 pmol mL(-1) CO2 (IQR, 265-765) for healthy versus 350 pmol mL(-1) CO2 (IQR, 180-1013) for cirrhotic participants. CV was 17  ±  6%. There remains an important unmet need in the evaluation of systemic ammonia, and breath measurement continues to demonstrate promise to fulfill this need. Given the many differences between breath and blood ammonia measurement, we examined biological explanations for our findings in healthy and cirrhotic participants. We conclude that based upon these preliminary data breath may offer clinically important information this is not provided by blood ammonia.

  1. Clinical utility of breath ammonia for evaluation of ammonia physiology in healthy and cirrhotic adults

    PubMed Central

    Spacek, Lisa A; Mudalel, Matthew; Tittel, Frank; Risby, Terence H; Solga, Steven F

    2016-01-01

    Blood ammonia is routinely used in clinical settings to assess systemic ammonia in hepatic encephalopathy and urea cycle disorders. Despite its drawbacks, blood measurement is often used as a comparator in breath studies because it is a standard clinical test. We sought to evaluate sources of measurement error and potential clinical utility of breath ammonia compared to blood ammonia. We measured breath ammonia in real time by quartz enhanced photoacoustic spectrometry and blood ammonia in 10 healthy and 10 cirrhotic participants. Each participant contributed 5 breath samples and blood for ammonia measurement within 1 h. We calculated the coefficient of variation (CV) for 5 breath ammonia values, reported medians of healthy and cirrhotic participants, and used scatterplots to display breath and blood ammonia. For healthy participants, mean age was 22 years (±4), 70% were men, and body mass index (BMI) was 27 (±5). For cirrhotic participants, mean age was 61 years (±8), 60% were men, and BMI was 31 (±7). Median blood ammonia for healthy participants was within normal range, 10 μmol L−1 (interquartile range (IQR), 3–18) versus 46 μmol L−1 (IQR, 23–66) for cirrhotic participants. Median breath ammonia was 379 pmol mL−1 CO2 (IQR, 265–765) for healthy versus 350 pmol mL−1 CO2 (IQR, 180–1013) for cirrhotic participants. CV was 17 ± 6%. There remains an important unmet need in the evaluation of systemic ammonia, and breath measurement continues to demonstrate promise to fulfill this need. Given the many differences between breath and blood ammonia measurement, we examined biological explanations for our findings in healthy and cirrhotic participants. We conclude that based upon these preliminary data breath may offer clinically important information this is not provided by blood ammonia. PMID:26658550

  2. Autotrophic ammonia oxidation by soil thaumarchaea.

    PubMed

    Zhang, Li-Mei; Offre, Pierre R; He, Ji-Zheng; Verhamme, Daniel T; Nicol, Graeme W; Prosser, James I

    2010-10-01

    Nitrification plays a central role in the global nitrogen cycle and is responsible for significant losses of nitrogen fertilizer, atmospheric pollution by the greenhouse gas nitrous oxide, and nitrate pollution of groundwaters. Ammonia oxidation, the first step in nitrification, was thought to be performed by autotrophic bacteria until the recent discovery of archaeal ammonia oxidizers. Autotrophic archaeal ammonia oxidizers have been cultivated from marine and thermal spring environments, but the relative importance of bacteria and archaea in soil nitrification is unclear and it is believed that soil archaeal ammonia oxidizers may use organic carbon, rather than growing autotrophically. In this soil microcosm study, stable isotope probing was used to demonstrate incorporation of (13)C-enriched carbon dioxide into the genomes of thaumarchaea possessing two functional genes: amoA, encoding a subunit of ammonia monooxygenase that catalyses the first step in ammonia oxidation; and hcd, a key gene in the autotrophic 3-hydroxypropionate/4-hydroxybutyrate cycle, which has been found so far only in archaea. Nitrification was accompanied by increases in archaeal amoA gene abundance and changes in amoA gene diversity, but no change was observed in bacterial amoA genes. Archaeal, but not bacterial, amoA genes were also detected in (13)C-labeled DNA, demonstrating inorganic CO(2) fixation by archaeal, but not bacterial, ammonia oxidizers. Autotrophic archaeal ammonia oxidation was further supported by coordinate increases in amoA and hcd gene abundance in (13)C-labeled DNA. The results therefore provide direct evidence for a role for archaea in soil ammonia oxidation and demonstrate autotrophic growth of ammonia oxidizing archaea in soil.

  3. An assessment of ammonia emissions from dairy facilities in Pennsylvania.

    PubMed

    Ferguson, J D; Dou, Z; Ramberg, C F

    2001-10-26

    A survey of 715 Holstein dairy farms in Pennsylvania was used to construct demographics for the average Holstein dairy farm. The average Holstein dairy farm was composed of 69 lactating cows; 11 nonlactating, pregnant cows; 44 heifers; and 18 calves. Milk production averaged 27.3 kg (60.0 lb). Crop area averaged 73.6 ha. Milk production, crop area and type, average county yields, and herd animal groups were used to construct a typical feeding program for these farms. Typical rations were constructed for six feeding groups (three milk production groups, one nonlactating group, two heifer groups) to meet milk production, pregnancy, and growth requirements. Rations were constructed based on three forage qualities (excellent, average, and poor) typically observed on Pennsylvania dairy farms. Data for animal description (milk production, body weight, growth, and pregnancy status) and ration components and amounts consumed for each animal group were input into the excretion model of the Dairy Nutrient Planner computer program (DNP). Excretion of fecal N and dry matter (DM), urinary N, and total P and K were produced for each animal group and used to assess potential volatile losses of N. Work at the Marshak Dairy, New Bolton Center, indicates the majority of urinary N is rapidly lost as ammonia from dairy facilities. Based on this observation, the losses of N as ammonia were estimated to be 4.63, 4.62, and 4.28 tonne/year for the farm with excellent, average, and poor quality forages, respectively. Volatile losses of N may be reduced most by controlling levels of urea in urine. Urinary N may be reduced through dietary manipulation of protein and carbohydrate sources. Conversion of urea to ammonia may be reduced by altering the pH of barn floors and gutters. Entrapment of ammonia may be accomplished by acidification of manure slurry. Atmospheric ammonia contributes to acid rain, eutrophication of estuaries and lakes, and particulate air pollution. Reduction of ammonia

  4. An assessment of ammonia emissions from dairy facilities in Pennsylvania.

    PubMed

    Ferguson, J D; Dou, Z; Ramberg, C F

    2001-10-26

    A survey of 715 Holstein dairy farms in Pennsylvania was used to construct demographics for the average Holstein dairy farm. The average Holstein dairy farm was composed of 69 lactating cows; 11 nonlactating, pregnant cows; 44 heifers; and 18 calves. Milk production averaged 27.3 kg (60.0 lb). Crop area averaged 73.6 ha. Milk production, crop area and type, average county yields, and herd animal groups were used to construct a typical feeding program for these farms. Typical rations were constructed for six feeding groups (three milk production groups, one nonlactating group, two heifer groups) to meet milk production, pregnancy, and growth requirements. Rations were constructed based on three forage qualities (excellent, average, and poor) typically observed on Pennsylvania dairy farms. Data for animal description (milk production, body weight, growth, and pregnancy status) and ration components and amounts consumed for each animal group were input into the excretion model of the Dairy Nutrient Planner computer program (DNP). Excretion of fecal N and dry matter (DM), urinary N, and total P and K were produced for each animal group and used to assess potential volatile losses of N. Work at the Marshak Dairy, New Bolton Center, indicates the majority of urinary N is rapidly lost as ammonia from dairy facilities. Based on this observation, the losses of N as ammonia were estimated to be 4.63, 4.62, and 4.28 tonne/year for the farm with excellent, average, and poor quality forages, respectively. Volatile losses of N may be reduced most by controlling levels of urea in urine. Urinary N may be reduced through dietary manipulation of protein and carbohydrate sources. Conversion of urea to ammonia may be reduced by altering the pH of barn floors and gutters. Entrapment of ammonia may be accomplished by acidification of manure slurry. Atmospheric ammonia contributes to acid rain, eutrophication of estuaries and lakes, and particulate air pollution. Reduction of ammonia

  5. [¹³N]Ammonia positron emission tomographic/computed tomographic imaging targeting glutamine synthetase expression in prostate cancer.

    PubMed

    Shi, Xinchong; Zhang, Xiangsong; Yi, Chang; Liu, Yubo; He, Qiao

    2014-01-01

    The purpose of this study was to investigate the expression of glutamine synthetase (GS) in prostate cancer (PCa) and the utility of [¹³N]ammonia positron emission tomography/computed tomography (PET/CT) in the imaging of PCa. The uptake ratio of [¹³N]ammonia and the expression of GS in PC3 and DU145 cells was measured. Thirty-four patients with suspected PCa underwent [¹³N]ammonia PET/CT imaging, and immunohistochemistry staining of GS was performed. The uptake of [¹³N]ammonia in PC3 and DU145 cells elevated along with the decrease in glutamine in medium. The expression of GS messenger ribonucleic acid and protein also increased when glutamine was deprived. In biopsy samples, the GS expression scores were significantly higher in PCa tissue than in benign tissues (p < .001), and there was a positive correlation between the maximum GS expression scores and Gleason scores (Spearman r  =  .52). In 34 patients, [¹³N]ammonia uptake in PCa segments was significantly higher than that in benign segments (p ≤ .01), and there was a weak correlation between GS expression scores and the uptake of [¹³N]ammonia (Spearman r  =  .47). The expression of GS in PCa cells upregulated along with the deprivation of glutamine. GS is the main reason for the uptake of [¹³N]ammonia, and [¹³N]ammonia is a useful tracer for PCa imaging.

  6. Innovative ammonia stripping with an electrolyzed water system as pretreatment of thermally hydrolyzed wasted sludge for anaerobic digestion.

    PubMed

    Park, Seyong; Kim, Moonil

    2015-01-01

    In this study, the anaerobic digestion of thermally hydrolyzed wasted sludge (THWS) with a high concentration of ammonia was carried out through combining with an ammonia stripping and an electrolyzed water system (EWS). The EWS produced acidic water (pH 2-3) at the anode and alkaline water (pH 11-12) at the cathode with an electro-diaphragm between the electrodes that could be applied to ammonia stripping. The ammonia stripping efficiency was strongly dependent on the pH and aeration rate, and the ammonium ion removal rate followed pseudo-first-order kinetics. From the BMP test, the methane yield of THWS after ammonia stripping using the EWS was 2.8 times higher than that of the control process (raw THWS without ammonia stripping). Furthermore, both methane yield and ammonium removal efficiency were higher in this study than in previous studies. Since ammonia stripping with the EWS does not require any chemicals for pH control, no precipitated sludge is produced and anaerobic microorganisms are not inhibited by cations. Therefore, ammonia stripping using the EWS could be an effective method for digestion of wastewater with a high concentration of ammonium nitrogen.

  7. Physiological responses of plant leaves to atmospheric ammonia and ammonium

    NASA Astrophysics Data System (ADS)

    Pearson, J.; Soares, A.

    Misting of leaves of several plant species with 3 mM aqueous NH +4 at pH 5, or fumigation with 3000 μg m -3 gaseous NH 3 for 1 h, elicits similar biochemical and physiological changes in the species tested. The enzyme glutamine synthetase (GS) was shown to increase its activity in all species, while that of nitrate reductase (NR) was inhibited, at least in those species which possessed the ability to induce foliar NR. At the same time there were marked changes in organic anion concentrations, with malate and citrate in particular being reduced in concentration, following either NH +4 or NH 3 application to leaves. The changes in organic anions are also discussed in the light of pH regulation by the cell. A stimulation of photosynthesis was also evident when leaves were treated with either NH 3 or NH +4. It is argued that, because of the differences in solution chemistry of the two ammonia forms, the aqueous form applied at pH 5 and the gaseous form being an alkali in solution, these changes can only have occurred through the ability of the leaves to readily assimilate both forms of the ammonia. The biochemical changes might have potential as markers for the onset of physiological perturbation by atmospheric ammonia pollution, particularly changes in organic acid concentration; their use in an index of pollution stress is briefly discussed.

  8. Reversible Ammonia Sorption for the Primary Life Support System (PLSS)

    NASA Technical Reports Server (NTRS)

    Wojtowicz, Marek A.; Cosgrove, Joseph E.; Serio, Michael A.; Jennings, Mallory A.

    2012-01-01

    Results are presented on the development of regenerable trace-contaminant (TC) sorbent for use in Extravehicular Activities (EVAs), and more specifically in the Primary Life Support System (PLSS). Since ammonia is the most important TC to be captured, data presented in this paper are limited to ammonia sorption, with results relevant to other TCs to be reported at a later time. The currently available TC-control technology involves the use of a packed bed of acid-impregnated granular charcoal. The sorbent is non-regenerable, and its use is associated with appreciable pressure drop, i.e. power consumption. The objective of this work is to demonstrate the feasibility of using vacuum-regenerable sorbents for PLSS application. In this study, several carbon sorbent monoliths were fabricated and tested. Multiple adsorption/vacuum-regeneration cycles were demonstrated at room temperature, as well as carbon surface conditioning that enhances ammonia sorption without impairing sorbent regeneration. Depending on sorbent monolith geometry, the reduction in pressure drop with respect to granular sorbent was found to be between 50% and two orders of magnitude. Resistive heating of the carbon sorbent monolith was demonstrated by applying voltage to the opposite ends of the monolith.

  9. Procurement of exogenous ammonia by the swallowtail butterfly, Papilio polytes, for protein biosynthesis and sperm production

    NASA Astrophysics Data System (ADS)

    Honda, Keiichi; Takase, Hiroyuki; Ômura, Hisashi; Honda, Hiroshi

    2012-09-01

    How to acquire sufficient quantity of nitrogen is a pivotal issue for herbivores, particularly for lepidopterans (butterflies and moths) of which diet quality greatly differs among their life stages. Male Lepidoptera often feed from mud puddles, dung, and carrion, a behavior known as puddling, which is thought to be supplementary feeding targeted chiefly at sodium. During copulation, males transfer a spermatophore to females that contains, besides sperm, nutrients (nuptial gifts) rich in sodium, proteins, and amino acids. However, it is still poorly understood how adults, mostly nectarivores, extract nitrogen from the environment. We examined the availability of two ubiquitous inorganic nitrogenous ions in nature, viz. ammonium (or ammonia) and nitrate ions, as nutrients in a butterfly, and show that exogenous ammonia ingested by adult males of the swallowtail, Papilio polytes, can serve as a resource for protein biosynthesis. Feeding experiments with 15N-labeled ammonium chloride revealed that nitrogen was incorporated into eupyrene spermatozoa, seminal protein, and thoracic muscle. Ammonia uptake by males significantly increased the number of eupyrene sperms in the reproductive tract tissues. The females also had the capacity to assimilate ammonia into egg protein. Consequently, it is evident that acquired ammonia is utilized for the replenishment of proteins allocable for reproduction and somatic maintenance. The active exploitation of exogenous ammonia as a nutrient by a butterfly would foster better understanding of the foraging and reproductive strategies in insects.

  10. A Cyanine Dye Encapsulated Porous Fibrous Mat for Naked-Eye Ammonia Sensing.

    PubMed

    Ji, Chendong; Ma, Lijing; Yin, Meizhen; Yang, Wantai; Pan, Kai

    2016-08-19

    Electrospun ultrathin fiber-based sensors are desirable because of their practicality and sensitivity. Ammonia-detection systems are in high demand in different areas, including the industrial and agricultural fields. However, current technologies rely on large and complex instruments that restrict their actual utilization. Herein, we report a flexible naked-eye ammonia sensor, the polylactic acid-cyanine (PLA-Cy) fibrous mat, which was fabricated by blending a carboxyl-functionalized cyanine dye (D1) into electospun PLA porous fibers. The sensing mat was shown to undergo a naked-eye-detectable color change from white to blue upon exposure to ammonia vapor. The mat showed high selectivity to ammonia gas with a detection limit of 3.3 ppm. Aggregated D1 was first encapsulated by PLA and was then ionized by NH3 . These mechanisms were examined by photophysical studies and scanning electron microscopy. The aggregation-deaggregation process of D1 in the PLA-Cy fibrous mat led to the color change. This work provides a facile method for the naked-eye detection of ammonia and a novel strategy for the use of organic dyes in ammonia sensing.

  11. Ammonia-LCFA synergetic co-inhibition effect in manure-based continuous biomethanation process.

    PubMed

    Wang, Han; Fotidis, Ioannis A; Angelidaki, Irini

    2016-06-01

    In the current study it has been hypothesized that, when organic loading of an anaerobic reactor is increased, the additional cell biomass biosynthesis would capture more ammonia nitrogen and thereby reduce the ammonia toxicity. Therefore, the alleviation of the toxicity of high ammonia levels using lipids (glycerol trioleate-GTO) or carbohydrates (glucose-GLU) as co-substrates in manure-based thermophilic continuous stirred-tank reactors (R(GTO) and R(GLU), respectively) was tested. At 5gNH4(+)-NL(-1), relative methane production of R(GTO) and R(GLU), was 10.5% and 41% compared to the expected uninhibited production, respectively. At the same time control reactor (R(CTL)), only fed with manure, reached 32.7% compared to the uninhibited basis production. Therefore, it seems that using lipids to counteract the ammonia effect in CSTR reactors creates an "ammonia-LCFA (long chain fatty acids) synergetic co-inhibition" effect. Moreover, co-digestion with glucose in R(GLU) was more robust to ammonia toxicity compared to R(CTL).

  12. A Cyanine Dye Encapsulated Porous Fibrous Mat for Naked-Eye Ammonia Sensing.

    PubMed

    Ji, Chendong; Ma, Lijing; Yin, Meizhen; Yang, Wantai; Pan, Kai

    2016-08-19

    Electrospun ultrathin fiber-based sensors are desirable because of their practicality and sensitivity. Ammonia-detection systems are in high demand in different areas, including the industrial and agricultural fields. However, current technologies rely on large and complex instruments that restrict their actual utilization. Herein, we report a flexible naked-eye ammonia sensor, the polylactic acid-cyanine (PLA-Cy) fibrous mat, which was fabricated by blending a carboxyl-functionalized cyanine dye (D1) into electospun PLA porous fibers. The sensing mat was shown to undergo a naked-eye-detectable color change from white to blue upon exposure to ammonia vapor. The mat showed high selectivity to ammonia gas with a detection limit of 3.3 ppm. Aggregated D1 was first encapsulated by PLA and was then ionized by NH3 . These mechanisms were examined by photophysical studies and scanning electron microscopy. The aggregation-deaggregation process of D1 in the PLA-Cy fibrous mat led to the color change. This work provides a facile method for the naked-eye detection of ammonia and a novel strategy for the use of organic dyes in ammonia sensing. PMID:27411059

  13. Ammonia-LCFA synergetic co-inhibition effect in manure-based continuous biomethanation process.

    PubMed

    Wang, Han; Fotidis, Ioannis A; Angelidaki, Irini

    2016-06-01

    In the current study it has been hypothesized that, when organic loading of an anaerobic reactor is increased, the additional cell biomass biosynthesis would capture more ammonia nitrogen and thereby reduce the ammonia toxicity. Therefore, the alleviation of the toxicity of high ammonia levels using lipids (glycerol trioleate-GTO) or carbohydrates (glucose-GLU) as co-substrates in manure-based thermophilic continuous stirred-tank reactors (R(GTO) and R(GLU), respectively) was tested. At 5gNH4(+)-NL(-1), relative methane production of R(GTO) and R(GLU), was 10.5% and 41% compared to the expected uninhibited production, respectively. At the same time control reactor (R(CTL)), only fed with manure, reached 32.7% compared to the uninhibited basis production. Therefore, it seems that using lipids to counteract the ammonia effect in CSTR reactors creates an "ammonia-LCFA (long chain fatty acids) synergetic co-inhibition" effect. Moreover, co-digestion with glucose in R(GLU) was more robust to ammonia toxicity compared to R(CTL). PMID:26985628

  14. Vapor Phase Catalytic Ammonia Reduction

    NASA Technical Reports Server (NTRS)

    Flynn, Michael T.; Harper, Lynn D. (Technical Monitor)

    1994-01-01

    This paper discusses the development of a Vapor Phase Catalytic Ammonia Reduction (VPCAR) teststand and the results of an experimental program designed to evaluate the potential of the technology as a water purification process. In the experimental program the technology is evaluated based upon product water purity, water recovery rate, and power consumption. The experimental work demonstrates that the technology produces high purity product water and attains high water recovery rates at a relatively high specific power consumption. The experimental program was conducted in 3 phases. In phase I an Igepon(TM) soap and water mixture was used to evaluate the performance of an innovative Wiped-Film Rotating-Disk evaporator and associated demister. In phase II a phenol-water solution was used to evaluate the performance of the high temperature catalytic oxidation reactor. In phase III a urine analog was used to evaluate the performance of the combined distillation/oxidation functions of the processor.

  15. Dakota Gasification Company - ammonia scrubber

    SciTech Connect

    Wallach, D.L.

    1995-12-31

    Amain stack BACT assessment for sulfur dioxide emissions conducted in 1990 for the Dakota Gasification Company`s (DGC) Great Plains Synfuels Plant identified wet limestone flue gas desulfurization system as BACT. During the development of the design specification for the wet limestone FGD, GE Environmental Systems Inc. and DGC jointly demonstrated a new ammonia-based process for flue gas desulfurization on a large pilot plant located at the Great Plains Synfuels Plant. The production of saleable ammonium sulfate, rather than a waste product, was of interest to DGC as it fit into the plant`s on-going by-product recovery efforts. With the success of the pilot plant, DGC and GEESI entered into an agreement to build the first commercial scale Ammonium Sulfate Forced Oxidation FGD system. Construction of this system is well in progress with an anticipated start-up date of August, 1996.

  16. Nitrate Reduction to Nitrite, Nitric Oxide and Ammonia by Gut Bacteria under Physiological Conditions

    PubMed Central

    Tiso, Mauro; Schechter, Alan N.

    2015-01-01

    The biological nitrogen cycle involves step-wise reduction of nitrogen oxides to ammonium salts and oxidation of ammonia back to nitrites and nitrates by plants and bacteria. Neither process has been thought to have relevance to mammalian physiology; however in recent years the salivary bacterial reduction of nitrate to nitrite has been recognized as an important metabolic conversion in humans. Several enteric bacteria have also shown the ability of catalytic reduction of nitrate to ammonia via nitrite during dissimilatory respiration; however, the importance of this pathway in bacterial species colonizing the human intestine has been little studied. We measured nitrite, nitric oxide (NO) and ammonia formation in cultures of Escherichia coli, Lactobacillus and Bifidobacterium species grown at different sodium nitrate concentrations and oxygen levels. We found that the presence of 5 mM nitrate provided a growth benefit and induced both nitrite and ammonia generation in E.coli and L.plantarum bacteria grown at oxygen concentrations compatible with the content in the gastrointestinal tract. Nitrite and ammonia accumulated in the growth medium when at least 2.5 mM nitrate was present. Time-course curves suggest that nitrate is first converted to nitrite and subsequently to ammonia. Strains of L.rhamnosus, L.acidophilus and B.longum infantis grown with nitrate produced minor changes in nitrite or ammonia levels in the cultures. However, when supplied with exogenous nitrite, NO gas was readily produced independently of added nitrate. Bacterial production of lactic acid causes medium acidification that in turn generates NO by non-enzymatic nitrite reduction. In contrast, nitrite was converted to NO by E.coli cultures even at neutral pH. We suggest that the bacterial nitrate reduction to ammonia, as well as the related NO formation in the gut, could be an important aspect of the overall mammalian nitrate/nitrite/NO metabolism and is yet another way in which the microbiome

  17. Colonic luminal ammonia and portal blood L-glutamine and L-arginine concentrations: a possible link between colon mucosa and liver ureagenesis.

    PubMed

    Eklou-Lawson, Mamy; Bernard, Françoise; Neveux, Nathalie; Chaumontet, Catherine; Bos, Cécile; Davila-Gay, Anne-Marie; Tomé, Daniel; Cynober, Luc; Blachier, François

    2009-10-01

    The highest ammonia concentration in the body is found in the colon lumen and although there is evidence that this metabolite can be absorbed through the colonic epithelium, there is little information on the capacity of the colonic mucosa to transfer and metabolize this compound. In the present study, we used a model of conscious pig with a canula implanted into the proximal colon to inject endoluminally increasing amounts of ammonium chloride and to measure during 5 h the kinetics of ammonia and amino acid concentration changes in the portal and arterial blood. By injecting as a single dose from 1 to 5 g ammonia into the colonic lumen, a dose-related increase in ammonia concentration in the portal blood was recorded. Ammonia concentration remained unchanged in the arterial blood except for the highest dose tested, i.e. 5 g which thus apparently exceeds the hepatic ureagenesis capacity. By calculating the apparent net ammonia absorption, it was determined that the pig colonic epithelium has the capacity to absorb 4 g ammonia. Ammonia absorption through the colonic epithelium was concomitant with increase of L-glutamine and L-arginine concentrations in the portal blood. This coincided with the expression of both glutamate dehydrogenase and glutamine synthetase in isolated colonic epithelial cells. Since L-glutamine and L-arginine are known to represent activators for liver ureagenesis, we propose that increased portal concentrations of these amino acids following increased ammonia colonic luminal concentration represent a metabolic link between colon mucosa and liver urea biosynthesis.

  18. Characterization of tunnel mutants reveals a catalytic step in ammonia delivery by an aminoacyl-tRNA amidotransferase.

    PubMed

    Zhao, Liangjun; Rathnayake, Udumbara M; Dewage, Sajeewa W; Wood, Whitney N; Veltri, Anthony J; Cisneros, G Andrés; Hendrickson, Tamara L

    2016-09-01

    The Helicobacter pylori Asp-tRNA(A) (sn) /Glu-tRNA(G) (ln) amidotransferase (GatCAB) utilizes an uncommonly hydrophilic, ~ 40 Å ammonia tunnel for ammonia/ammonium transport between isolated active sites. Hydrophilicity of this tunnel requires a distinct ammonia transport mechanism, which hypothetically occurs through a series of deprotonation and protonation steps. To explore the initiation of this relay mechanism, the highly conserved tunnel residue D185 (in the GatA subunit) was enzymatically and computationally investigated by comparing D185A, D185N, and D185E mutant enzymes to wild-type GatCAB. Our results indicate that D185 acts as an acid/base residue, participating directly in catalysis. To our knowledge, this is the first example of acid/base chemistry in a glutamine-dependent amidotransferase ammonia tunnel. PMID:27500385

  19. Low-cost anodes for ammonia electrooxidation

    NASA Astrophysics Data System (ADS)

    Selverston, Steven M.

    This research focused on the development of low-cost electrodes for the electrochemical oxidation of ammonia to nitrogen, a reaction that has possible applications in hydrogen generation, direct ammonia fuel cells, water treatment, and sensors. Statistical design of experiments was used to help develop an efficient and scalable process for electrodeposition of platinum with a specific electrochemical surface area of over 25 m2 /g. Catalyst surface area and activity were evaluated using cyclic voltammetry, and the material microstructure and morphology were investigated using x-ray diffraction and scanning electron microscopy. The synthesized electrodes were found to be active toward the ammonia electrooxidation reaction, particularly when supporting electrolyte was added. However, supporting electrolyte was not required in order to oxidize the ammonia. As proof of concept, a homemade direct ammonia fuel cell employing a commercial anion exchange membrane was tested at room temperature with gravity-fed fuel and without supporting electrolyte. At room temperature, with passive reactant supply and using dissolved oxygen at the cathode, the cell produced about one quarter the power of a direct methanol fuel cell that used active transport of humidified oxygen and preheated (50 °C) methanol. With continued development of the membrane, cathode and membrane electrode assembly, the passive direct ammonia fuel cell using anion exchange membrane could have performance similar to the equivalent direct methanol fuel cell, and it could benefit from many advantages of ammonia over methanol such as lower cost, higher energy density, and reduced greenhouse gas emissions.

  20. Ammonia synthesis using magnetic induction method (MIM)

    NASA Astrophysics Data System (ADS)

    Puspitasari, P.; Razak, J. Abd; Yahya, N.

    2012-09-01

    The most challenging issues for ammonia synthesis is to get the high yield. New approach of ammonia synthesis by using Magnetic Induction Method (MIM) and the Helmholtz Coils has been proposed. The ammonia detection was done by using Kjeldahl Method and FTIR. The system was designed by using Autocad software. The magnetic field of MIM was vary from 100mT-200mT and the magnetic field for the Helmholtz coils was 14mT. The FTIR result shows that ammonia has been successfully formed at stretching peaks 1097,1119,1162,1236, 1377, and 1464 cm-1. UV-VIS result shows the ammonia bond at 195nm of wavelength. The ammonia yield was increase to 244.72μmole/g.h by using the MIM and six pairs of Helmholtz coils. Therefore this new method will be a new promising method to achieve the high yield ammonia at ambient condition (at 25δC and 1atm), under the Magnetic Induction Method (MIM).

  1. Highly compressed ammonia forms an ionic crystal.

    PubMed

    Pickard, Chris J; Needs, R J

    2008-10-01

    Ammonia is an important compound with many uses, such as in the manufacture of fertilizers, explosives and pharmaceuticals. As an archetypal hydrogen-bonded system, the properties of ammonia under pressure are of fundamental interest, and compressed ammonia has a significant role in planetary physics. We predict new high-pressure crystalline phases of ammonia (NH(3)) through a computational search based on first-principles density-functional-theory calculations. Ammonia is known to form hydrogen-bonded solids, but we predict that at higher pressures it will form ammonium amide ionic solids consisting of alternate layers of NH(4)(+) and NH(2)(-) ions. These ionic phases are predicted to be stable over a wide range of pressures readily obtainable in laboratory experiments. The occurrence of ionic phases is rationalized in terms of the relative ease of forming ammonium and amide ions from ammonia molecules, and the volume reduction on doing so. We also predict that the ionic bonding cannot be sustained under extreme compression and that, at pressures beyond the reach of current static-loading experiments, ammonia will return to hydrogen-bonded structures consisting of neutral NH(3) molecules. PMID:18724375

  2. Studies on the behavior of ammonia and ammonium salts in the atmosphere (1) - Fractional collection of ammonia gas and particulate ammonium

    NASA Technical Reports Server (NTRS)

    Kiin, K.; Fujimura, M.; Hashimoto, Y.

    1981-01-01

    Methods for the fractional collection of trace amounts of atmospheric ammonia gas and ammonium particles on a two staged glass fiber filter are summarized. A standard glass fiber filter washed with distilled water and dried at 120 to 130 C was used. A second filter was impregnated with a mixture of 3% boric acid and 25% glycerin solution. The blank of glass fiber filters impregnated with a mixture of the above solution was very low for ammonia, i.e. 0.06 micrograms in a filter of 47 mm in diameter. The mean concentrations of ammonia and ammonium in air at Kawasaki, a polluted area, were 7.6 and 2.3 micrograms cu m, and those at Sanriku, an unpolluted area 0.9 and 0.2 micrograms cu m, respectively. Ratios of concentration levels of ammonium to total ammonia in the atmosphere were 0.3 and 0.2 for the polluted and unpolluted areas, respectively. Ammonium salts in air at both areas were not correlated with relative humidity. Variations in time of ammonia concentrations and sources in surrounding areas are also considered.

  3. Removal of ammonia from air on molybdenum and tungsten oxide modified activated carbons.

    PubMed

    Petit, Camille; Bandosz, Teresa J

    2008-04-15

    Microporous coconut-based activated carbon was impregnated with solutions of ammonium metatungstate or ammonium molybdate and then calcined in air in order to convert the salts into their corresponding oxides. The surface of those materials was characterized using adsorption of nitrogen, potentiometric titration, Fourier-transform infrared spectroscopy, X-ray diffraction, and thermal analysis. The results indicated a significant increase in surface acidity related to the presence of tungsten or molybdenum oxides. On the materials obtained, adsorption of ammonia from either dry or moist air was carried out. The oxides distributed on the surface provided Lewis and/or Brønsted centers for interactions with ammonia molecules or ammonium ions. Water on the surface of carbon or in the gas phase increased the amount of ammonia adsorbed via involvement of Brønsted-type interactions and/or by leading to the formation of molybdate or tungstate salts on the surface. Although the amount of ammonia adsorbed is closely related to the number of moles of oxides and their acidic centers, the carbon surface also contributes to the adsorption via providing small pores where ammonia can be dissolved in the water film.

  4. Recovery of ammonia from poultry litter using flat gas permeable membranes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The use of flat gas-permeable membranes was investigated as components of a new process to capture and recover ammonia (NH3) in poultry houses. This process includes the passage of gaseous NH3 through a microporous hydrophobic membrane, capture with a circulating dilute acid on the other side of the...

  5. Degradation of spent craft brewer’s yeast by caprine rumen hyper ammonia-producing bacteria

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Spent brewer’s yeast has long been included in ruminant diets as a protein supplement. However, modern craft beers often include more hops (Humulus lupulus L.) compounds than traditional recipes. These compounds include alpha and beta-acids, which are antimicrobial to the rumen hyper ammonia-produci...

  6. Nutrition - An effective tool for mitigating ammonia emissions from dairy and feedlot operations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ammonia emitted from animal feeding operations is a potential environmental and human health hazard, contributing to eutrophication of surface waters and nitrate contamination of ground waters, soil acidity, and fine particulate matter formation. It may also contribute to global warming through nitr...

  7. Interactive effects of ammonia and light intensity on hematochemical variables in broiler chickens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study examined the influence of atmospheric ammonia exposure, light intensity, and their interaction on blood gases, electrolytes, and acid-base balance in broiler chickens under environmentally controlled conditions. The experiment consisted of a 3 × 3 factorial arranged in a randomized comple...

  8. Age-related Effects of Varying Ammonia Concentrations on Hematophysiological Variables in Broiler Chickens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study examined the response of different aged birds of the same genetic strain exposed to ammonia (NH3) at set concentrations on blood gases, electrolytes, and acid-base balance under environmentally controlled conditions. The experiment consisted of a 4 × 4 factorial with a randomized design. ...

  9. Ammonia adsorption capacity of biomass and animal-manure derived biochars

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this research was to characterize and investigate ammonia and hydrogen sulfide gas adsorption capacities of low- and high-temperature biochars made from wood shavings and chicken litter. The biochar samples were activated with steam or phosphoric acid. The specific surface areas and...

  10. AMMONIA REMOVAL FROM MAMMALIAN CELL CULTURE MEDIUM BY ION-EXCHANGE MEMBRANES

    EPA Science Inventory

    Metabolites such as ammonia and lactic acid formed during mammalian cell culture can frequently be toxic to the cells themselves beyond a threshold concentration of the metabolites. Cell culture conducted in the presence of such accumulated metabolites is therefore limited in pro...

  11. The aerosols' fate in a putative ammonia ocean on Titan

    NASA Astrophysics Data System (ADS)

    Ramírez, S. I.; Coll, P.; Buch, A.; Brassé, C.; Poch, O.; Raulin, F.

    2010-04-01

    -methyl-N-(tert-butyldimethylsilyl)-trifluoroacetamide in dimethylformamide, the products were identified and quantified by a GC-MS system. We found derived residues related to amino acids as well as urea, as shown by their mass spectra and chromatographic patterns. There seems to be a constant presence of alanine and glycine, no matter the ammonia concentrations to which the analogues were exposed. Our results have important astrobiological implications to Titan's environment particularly if the existence of the suggested subsurface water-ammonia liquids is validated. Titan is a place where organic compounds are produced and where liquid water might be present. Therefore, this kind of studies helps to better understand the geological processes of Titan's surface and its relationship with the active organic chemistry occurring in its atmosphere.

  12. Ammonia manipulates the ammonia-oxidizing archaea and bacteria in the coastal sediment-water microcosms.

    PubMed

    Zhang, Yan; Chen, Lujun; Dai, Tianjiao; Sun, Renhua; Wen, Donghui

    2015-08-01

    Ammonia was observed as a potential significant factor to manipulate the abundance and activity of ammonia-oxidizing microorganisms (AOMs) in water environments. For the first time, this study confirmed this phenomenon by laboratory cultivation. In a series of estuarine sediment-coastal water microcosms, we investigated the AOM's phylogenetic composition and activity change in response to ammonia concentration. Increase of ammonia concentration promoted bacterial amoA gene abundance in a linear pattern. The ratio of transcribed ammonia-oxidizing bacteria (AOB) amoA gene/ammonia-oxidizing archaea (AOA) amoA gene increased from 0.1 to 43 as NH4 (+)-N increased from less than 0.1 to 12 mg L(-1), and AOA amoA transcription was undetected under 20 mg NH4 (+)-N L(-1). The incubation of stable isotope probing (SIP) microcosms revealed a faster (13)C-NaHCO3 incorporation rate of AOA amoA gene under 0.1 mg NH4 (+)-N L(-1) and a sole (13)C-NaHCO3 utilization of the AOB amoA gene under 20 mg NH4 (+)-N L(-1). Our results indicate that ammonia concentration manipulates the structure of AOM. AOA prefers to live and perform higher amoA transcription activity than AOB in ammonia-limited water environments, and AOB tends to take the first contributor place in ammonia-rich ones.

  13. Assimilation of ammonia in Paracoccus denitrificans.

    PubMed

    Mikes, V; Chválová, H; Mátlová, L

    1991-01-01

    Two pathways serve for assimilation of ammonia in Paracoccus denitrificans. Glutamate dehydrogenase (NADP+) catalyzes the assimilation at a high NH4+ concentration. If nitrate serves as the nitrogen source, glutamate is synthesized by glutamate-ammonia ligase and glutamate synthase (NADPH). At a very low NH4+ concentration, all three enzymes are synthesized simultaneously. No direct relationship exists between glutamate dehydrogenase (NADP+) and glutamate-ammonia ligase in P. denitrificans, while the glutamate synthase (NADPH) activity changes in parallel with that of the latter enzyme. Ammonia does not influence the induction or repression of glutamate dehydrogenase (NADP+). The inner concentration of metabolites indicates a possible repression of glutamate dehydrogenase (NADP+) by the high concentration of glutamine or its metabolic products as in the case when NH4+ is formed by assimilative nitrate reduction. No direct effect of the intermediates of nitrate assimilation on the synthesis of glutamate dehydrogenase (NADP+) was observed. PMID:1688163

  14. Ammonia Affects Astroglial Proliferation in Culture

    PubMed Central

    Bodega, Guillermo; Segura, Berta; Ciordia, Sergio; Mena, María del Carmen; López-Fernández, Luis Andrés; García, María Isabel; Trabado, Isabel; Suárez, Isabel

    2015-01-01

    Primary cultures of rat astroglial cells were exposed to 1, 3 and 5 mM NH4Cl for up to 10 days. Dose- and time-dependent reductions in cell numbers were seen, plus an increase in the proportion of cells in the S phase. The DNA content was reduced in the treated cells, and BrdU incorporation diminished. However, neither ammonia nor ammonia plus glutamine had any effect on DNA polymerase activity. iTRAQ analysis showed that exposure to ammonia induced a significant reduction in histone and heterochromatin protein 1 expression. A reduction in cell viability was also noted. The ammonia-induced reduction of proliferative activity in these cultured astroglial cells seems to be due to a delay in the completion of the S phase provoked by the inhibition of chromatin protein synthesis. PMID:26421615

  15. Supercritical ammonia pretreatment of lignocellulosic materials

    SciTech Connect

    Chou, Y.C.T.; Scott, C.D.

    1986-01-01

    A pretreatment technique using ammonia in a supercritical or near-critical fluid state was shown to substantially enhance the susceptibility of polysaccharides in lignocellulosics to subsequent hydrolysis by Trichoderma reesei cellulase. Near-theoretical conversion of cellulose and 70-80% conversion of hemicellulose to sugars from supercritical ammonia pretreated hardwoods or agricultural byproducts were obtained with a small dosage of cellulase. This technique was less effective toward softwoods. The pretreatment results are discussed in light of the properties of supercritical fluids.

  16. Ammonia chemistry in a flameless jet

    SciTech Connect

    Zieba, Mariusz; Schuster, Anja; Scheffknecht, Guenter; Brink, Anders; Hupa, Mikko

    2009-10-15

    In this paper, the nitrogen chemistry in an ammonia (NH{sub 3}) doped flameless jet is investigated using a kinetic reactor network model. The reactor network model is used to explain the main differences in ammonia chemistry for methane (CH{sub 4})-containing fuels and methane-free fuels. The chemical pathways of nitrogen oxides (NO{sub x}) formation and destruction are identified using rate-of-production analysis. The results show that in the case of natural gas, ammonia reacts relatively late at fuel lean condition leading to high NO{sub x} emissions. In the pre-ignition zone, the ammonia chemistry is blocked due to the absence of free radicals which are consumed by methane-methyl radical (CH{sub 3}) conversion. In the case of methane-free gas, the ammonia reacted very rapidly and complete decomposition was reached in the fuel rich region of the jet. In this case the necessary radicals for the ammonia conversion are generated from hydrogen (H{sub 2}) oxidation. (author)

  17. Corrosion inhibitor for aqueous ammonia absorption system

    DOEpatents

    Phillips, B.A.; Whitlow, E.P.

    1998-09-22

    A method is described for inhibiting corrosion and the formation of hydrogen and thus improving absorption in an ammonia/water absorption refrigeration, air conditioning or heat pump system by maintaining the hydroxyl ion concentration of the aqueous ammonia working fluid within a selected range under anaerobic conditions at temperatures up to 425 F. This hydroxyl ion concentration is maintained by introducing to the aqueous ammonia working fluid an inhibitor in an amount effective to produce a hydroxyl ion concentration corresponding to a normality of the inhibitor relative to the water content ranging from about 0.015 N to about 0.2 N at 25 C. Also, working fluids for inhibiting the corrosion of carbon steel and resulting hydrogen formation and improving absorption in an ammonia/water absorption system under anaerobic conditions at up to 425 F. The working fluids may be aqueous solutions of ammonia and a strong base or aqueous solutions of ammonia, a strong base, and a specified buffer. 5 figs.

  18. Corrosion inhibitor for aqueous ammonia absorption system

    DOEpatents

    Phillips, Benjamin A.; Whitlow, Eugene P.

    1998-09-22

    A method of inhibiting corrosion and the formation of hydrogen and thus improving absorption in an ammonia/water absorption refrigeration, air conditioning or heat pump system by maintaining the hydroxyl ion concentration of the aqueous ammonia working fluid within a selected range under anaerobic conditions at temperatures up to 425.degree. F. This hydroxyl ion concentration is maintained by introducing to the aqueous ammonia working fluid an inhibitor in an amount effective to produce a hydroxyl ion concentration corresponding to a normality of the inhibitor relative to the water content ranging from about 0.015 N to about 0.2 N at 25.degree. C. Also, working fluids for inhibiting the corrosion of carbon steel and resulting hydrogen formation and improving absorption in an ammonia/water absorption system under anaerobic conditions at up to 425.degree. F. The working fluids may be aqueous solutions of ammonia and a strong base or aqueous solutions of ammonia, a strong base, and a specified buffer.

  19. Ammonia and the Interior of Titan

    NASA Astrophysics Data System (ADS)

    Lorenz, R. D.

    2002-12-01

    Titan's surface will be very different from those of the Galileans, not just because of interactions with the atmosphere, but because the internal evolution will have been unique. The incorporation of ammonia in the ices making up Titan will make the evolution of Titan's interior structure very different. The presence of ammonia was previously only hinted at by formation models and the remarkably thick nitrogen atmosphere. However, recent radar observations showing Iapetus' bright face to be surprisingly radar-dark also point to incorporation of ammonia in the ices of the Saturnian satellites, explaining Titan's radar-darkness too. Ammonia will have several effects. As is well-known, its freezing-point depression to 176K makes a liquid layer ('internal ocean') more likely. A significant difference compared with the Galileans is that the greater expansivity of ammonia solutions compared with pure water causes the adiabat to be steeper, and thus a greater temperature difference prevails across the liquid layer. This in turn leads to a higher Carnot efficiency for the mantle heat engine - by an order of magnitude compared with Callisto - suggesting endogenic activity may be more manifest on Titan than on its Galilean cousins. The replenishment of methane in Titan's atmosphere against photolysis requires either surface lakes, or volcanic replenishment. If plausible methane contents of water-ammonia cryolavas are assumed, the heat flux associated with volcanism can be easily accommodated by the expected radiogenic heat production in the rocky core.

  20. Formation of High-Purity Indium Oxide Nanoparticles and Their Application to Sensitive Detection of Ammonia.

    PubMed

    Bhardwaj, Sanjeev K; Bhardwaj, Neha; Kukkar, Manil; Sharma, Amit L; Kim, Ki-Hyun; Deep, Akash

    2015-01-01

    High-purity In₂O₃ nanoparticles were recovered from scrap indium tin oxide substrates in a stepwise process involving acidic leaching, liquid-liquid extraction with a phosphine oxide extractant, and combustion of the organic phase. The morphological and structural parameters of the recovered nanoparticles were investigated to support the formation of the desired products. These In₂O₃ nanoparticles were used for sensitive sensing of ammonia gas using a four-probe electrode device. The proposed sensor offered very quick response time (around 10 s) and highly sensitive detection of ammonia (at a detection limit of 1 ppm).

  1. Control of Nitrogen Dioxide in Stack Emission by Reaction with Ammonia

    NASA Technical Reports Server (NTRS)

    Metzler, A. J.; Stevenson, E. F.

    1970-01-01

    The development of an acid base gas-phase reaction system which utilizes anhydrous ammonia as the reactant to remove nitrogen dioxide from hydrazine-nitrogen tetroxide rocket combustion exhaust is reported. This reaction reduced NO2 levels in exhaust emissions so that the resulting stack emission is completely white instead of the earlier observed typical reddish-brown coloration. Preliminary analyses indicate the importance of reaction time and ammonia concentration on removal efficiency and elimination of the health hazard to individuals with respiratory problems.

  2. Formation of High-Purity Indium Oxide Nanoparticles and Their Application to Sensitive Detection of Ammonia

    PubMed Central

    Bhardwaj, Sanjeev K.; Bhardwaj, Neha; Kukkar, Manil; Sharma, Amit L.; Kim, Ki-Hyun; Deep, Akash

    2015-01-01

    High-purity In2O3 nanoparticles were recovered from scrap indium tin oxide substrates in a stepwise process involving acidic leaching, liquid-liquid extraction with a phosphine oxide extractant, and combustion of the organic phase. The morphological and structural parameters of the recovered nanoparticles were investigated to support the formation of the desired products. These In2O3 nanoparticles were used for sensitive sensing of ammonia gas using a four-probe electrode device. The proposed sensor offered very quick response time (around 10 s) and highly sensitive detection of ammonia (at a detection limit of 1 ppm). PMID:26694415

  3. Antimicrobial Effects of Red Clover (Trifolium pratense) Phenolic Extract on the Ruminal Hyper Ammonia-producing Bacterium, Clostridium sticklandii SR

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ruminal proteolysis and subsequent amino acid degradation represent considerable economic loss in ruminant production. The hyper ammonia-producing bacteria (HAB) are responsible for amino acid deamination in the rumen. HAB can be controlled with ionophores, but they are also susceptible to plant-sy...

  4. Recovery of ammonia from swine manure using gas-permeable membranes: Effect of waste strength and pH

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nitrogen recovery of swine manure was investigated using gas-permeable membranes. The process involved a continuous recirculation of an acidic solution through a tubular gas-permeable membrane submerged in a manure filled vessel. Ammonia contained in manure was concentrated in the acidic solution ...

  5. Factors affecting the removal of ammonia from air on carbonaceous materials: Investigation of reactive adsorption mechanism

    NASA Astrophysics Data System (ADS)

    Petit, Camille

    Air pollution related to the release of industrial toxic gases, represents one of the main concerns of our modern world owing to its detrimental effect on the environment. To tackle this growing issue, efficient ways to reduce/control the release of pollutants are required. Adsorption of gases on porous materials appears as a potential solution. However, the physisorption of small molecules of gases such as ammonia is limited at ambient conditions. For their removal, adsorbents providing strong adsorption forces must be used/developed. In this study, new carbon-based materials are prepared and tested for ammonia adsorption at ambient conditions. Characterization of the adsorbents' texture and surface chemistry is performed before and after exposure to ammonia to identify the features responsible for high adsorption capacity and for controlling the mechanisms of retention. The characterization techniques include: nitrogen adsorption, thermal analysis, potentiometric titration, FT-IR spectroscopy, X-ray diffraction, Energy Dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy and Electron Microscopy. The results obtained indicate that ammonia removal is governed by the adsorbent's surface chemistry. On the contrary, porosity (and thus physisorption) plays a secondary role in this process, unless strong dispersive forces are provided by the adsorbent. The surface chemistry features responsible for the enhanced ammonia adsorption include the presence of oxygen-(carboxyl, hydroxyl, epoxy) and sulfur- (sulfonic) containing groups. Metallic species improve the breakthrough capacity as well as they lead to the formation of Lewis acid-base interactions, hydrogen-bonding or complexation. In addition to the latter three mechanisms, ammonia is retained on the adsorbent surface via Bronsted acid-base interactions or via specific reactions with the adsorbent's functionalities leading to the incorporation of ammonia into the adsorbent's matrix. Another mechanism

  6. Ammonia excretion in the Atlantic hagfish (Myxine glutinosa) and responses of an Rhc glycoprotein.

    PubMed

    Edwards, Susan L; Arnold, Justin; Blair, Salvatore D; Pray, Margaret; Bradley, Rachel; Erikson, Olivia; Walsh, Patrick J

    2015-05-01

    Hagfishes, the most ancient of the extant craniates, demonstrate a high tolerance for a number of unfavorable environmental conditions, including elevated ammonia. Proposed mechanisms of ammonia excretion in aquatic organisms include vesicular NH(4)(+) transport and release by exocytosis in marine crabs, and passive NH(3) diffusion, active NH(4)(+) transport, and paracellular leakage of NH3 or NH(4)(+) across the gills of fishes. Recently, an emerging paradigm suggests that Rhesus glycoproteins play a vital role in ammonia transport in both aquatic invertebrates and vertebrates. This study has identified an Rh glycoprotein ortholog from the gills of Atlantic hagfish. The hagfish Rhcg shares a 56-60% amino acid identity to other vertebrate Rhcg cDNAs. Sequence information was used to produce an anti-hagfish Rhcg (hRhcg) antibody. We have used hRhcg to localize protein expression to epithelial cells of the gill and the skin. In addition, we have quantified hRhcg expression following exposure to elevated plasma ammonia levels. Animals exposed to a 3 mmol/kg NH(4)Cl load resulted in significantly elevated plasma ammonia concentrations compared with controls for up to 4 h postinjection. This correlated with net ammonia excretion rates that were also significantly elevated for up to 4 h postinjection. Rhcg mRNA expression in both the gill and skin was significantly elevated by 15 min and 1 h, respectively, and hRhcg protein expression in gills was significantly elevated at 2, 4, and 8 h postinjection. These results demonstrate a potential role for Rhcg in the excretion of ammonia in the Atlantic hagfish.

  7. Atmospheric ammonia over China: emission estimates and impacts on air quality

    NASA Astrophysics Data System (ADS)

    Zhang, Lin; Zhao, Yuanhong; Chen, Youfan; Henze, Daven

    2016-04-01

    Ammonia (NH3) in the atmosphere is an important precursor of inorganic aerosols, and its deposition through wet and dry processes can cause adverse effects on ecosystems. The ammonia emissions over China are particularly large due to intensive agricultural activities, yet our current estimates of Chinese ammonia emissions and associated consequences on air quality are subject to large errors. Here we use the GEOS-Chem chemical transport model and its adjoint model to better quantify this issue. The TES satellite observations of ammonia concentrations and surface measurements of wet deposition fluxes are assimilated into the model to constrain the ammonia emissions over China. Optimized emissions show a strong seasonal variability with emissions in summer a factor of 3 higher than winter. We improve the bottom-up estimate of Chinese ammonia emissions from fertilizer use by using more practical feritilizer application rates for different crop types, which explains most of the discrepancies between our top-down estimates and prior emission estimates. We further use the GEOS-Chem adjoint at 0.25x0.3125 degree resolution to examine the sources contributing to the PM2.5 air pollution over North China. We show that wintertime PM2.5 over Beijing is largely contributed by residential and industrial sources, and ammonia emissions from agriculture activities. PM2.5 concentrations over North China are particularly sensitive to NH3 emissions in cold seasons due to strong nitrate formation. By converting shorted-lived nitric acid to aerosol nitrate, NH3 significantly promotes the regional transport influences of PM2.5 sources.

  8. Ammonia transformations and abundance of ammonia oxidizers in a clay soil underlying a manure pond.

    PubMed

    Sher, Yonatan; Baram, Shahar; Dahan, Ofer; Ronen, Zeev; Nejidat, Ali

    2012-07-01

    Unlined manure ponds are constructed on clay soil worldwide to manage farm waste. Seepage of ammonia-rich liquor into underlying soil layers contributes to groundwater contamination by nitrate. To identify the possible processes that lead to the production of nitrate from ammonia in this oxygen-limited environment, we studied the diversity and abundance of ammonia-transforming microorganisms under an unlined manure pond. The numbers of ammonia-oxidizing bacteria and anammox bacteria were most abundant in the top of the soil profile and decreased significantly with depth (0.5 m), correlating with soil pore-water ammonia concentrations and soil ammonia concentrations, respectively. On the other hand, the numbers of ammonia-oxidizing archaea were relatively constant throughout the soil profile (10(7) amoA copies per g(soil)). Nitrite-oxidizing bacteria were detected mainly in the top 0.2 m. The results suggest that nitrate accumulation in the vadose zone under the manure pond could be the result of complete aerobic nitrification (ammonia oxidation to nitrate) and could exist as a byproduct of anammox activity. While the majority of the nitrogen was removed within the 0.5-m soil section, possibly by combined anammox and heterotrophic denitrification, a fraction of the produced nitrate leached into the groundwater.

  9. Importance of ammonia pressure in the kinetics of ammonia synthesis over supported Ru

    SciTech Connect

    Holzman, P.R.; Shiflett, W.K.; Dumesic, J.A.

    1980-03-01

    This study examines the ammonia dependence of the synthesis rate over supported (but unpromoted) ruthenium using data collected with a flow reactor coupled with effluent ammonia determination. Silica gel and ..gamma..-alumina powder were impregnated to Ca. 1.0 to 1.3 wt % ruthenium loading by incipient wetness using an aqueous solution of RuCl/sub 3/ . 3 H/sub 2/O. Following this impregnation, the samples were dried overnight in air at 380 K, and then a portion, 1.5 g in the case of the silica-supported sample and 2.2 g in the case of the alumina-supported sample, was loaded into a flow reactor for hydrogen reduction (at 700K for ca. 50h) and subsequent ammonia synthesis studies at atmospheric pressure (0.1 MPa). This study has yielded ammonia synthesis turnover frequencies and apparent activation energies at constant flow rate that are in good agreement with the results of Ozaki et al. This study has also shown that the rate of ammonia synthesis does indeed exhibit an ammonia dependence in the same range of ammonia pressures studied by Ozaki et al. Apparent activation energies calculated at constant ammonia pressure are greater than those determined at constant flow rate. 6 figures, 1 table. (DP)

  10. Ammonia formation by metal-ligand cooperative hydrogenolysis of a nitrido ligand

    NASA Astrophysics Data System (ADS)

    Askevold, Bjorn; Nieto, Jorge Torres; Tussupbayev, Samat; Diefenbach, Martin; Herdtweck, Eberhardt; Holthausen, Max C.; Schneider, Sven

    2011-07-01

    Bioinspired hydrogenation of N2 to ammonia at ambient conditions by stepwise nitrogen protonation/reduction with metal complexes in solution has experienced remarkable progress. In contrast, the highly desirable direct hydrogenation with H2 remains difficult. In analogy to the heterogeneously catalysed Haber-Bosch process, such a reaction is conceivable via metal-centred N2 splitting and unprecedented hydrogenolysis of the nitrido ligands to ammonia. We report the synthesis of a ruthenium(IV) nitrido complex. The high nucleophilicity of the nitrido ligand is demonstrated by unusual N-C coupling with π-acidic CO. Furthermore, the terminal nitrido ligand undergoes facile hydrogenolysis with H2 at ambient conditions to produce ammonia in high yield. Kinetic and quantum chemical examinations of this reaction suggest cooperative behaviour of a phosphorus-nitrogen-phosphorus pincer ligand in rate-determining heterolytic hydrogen splitting.

  11. Consolidated conversion of protein waste into biofuels and ammonia using Bacillus subtilis.

    PubMed

    Choi, Kwon-Young; Wernick, David G; Tat, Christine A; Liao, James C

    2014-05-01

    The non-recyclable use of nitrogen fertilizers in microbial production of fuels and chemicals remains environmentally detrimental. Conversion of protein wastes into biofuels and ammonia by engineering nitrogen flux in Escherichia coli has been demonstrated as a method to reclaim reduced-nitrogen and curb its environmental deposition. However, protein biomass requires a proteolysis process before it can be taken up and converted by any microbe. Here, we metabolically engineered Bacillus subtilis to hydrolyze polypeptides through its secreted proteases and to convert amino acids into advanced biofuels and ammonia fertilizer. Redirection of B. subtilis metabolism for amino-acid conversion required inactivation of the branched-chain amino-acid (BCAA) global regulator CodY. Additionally, the lipoamide acyltransferase (bkdB) was deleted to prevent conversion of branched-chain 2-keto acids into their acyl-CoA derivatives. With these deletions and heterologous expression of a keto-acid decarboxylase and an alcohol dehydrogenase, the final strain produced biofuels and ammonia from an amino-acid media with 18.9% and 46.6% of the maximum theoretical yield. The process was also demonstrated on several waste proteins. The results demonstrate the feasibility of direct microbial conversion of polypeptides into sustainable products.

  12. FORMATION OF HYDROXYLAMINE ON DUST GRAINS VIA AMMONIA OXIDATION

    SciTech Connect

    He, Jiao; Vidali, Gianfranco; Lemaire, Jean-Louis; Garrod, Robin T.

    2015-01-20

    The quest to detect prebiotic molecules in space, notably amino acids, requires an understanding of the chemistry involving nitrogen atoms. Hydroxylamine (NH{sub 2}OH) is considered a precursor to the amino acid glycine. Although not yet detected, NH{sub 2}OH is considered a likely target of detection with ALMA. We report on an experimental investigation of the formation of hydroxylamine on an amorphous silicate surface via the oxidation of ammonia. The experimental data are then fed into a simulation of the formation of NH{sub 2}OH in dense cloud conditions. On ices at 14 K and with a modest activation energy barrier, NH{sub 2}OH is found to be formed with an abundance that never falls below a factor 10 with respect to NH{sub 3}. Suggestions of conditions for future observations are provided.

  13. Characterisation of terrestrial acidophilic archaeal ammonia oxidisers and their inhibition and stimulation by organic compounds.

    PubMed

    Lehtovirta-Morley, Laura E; Ge, Chaorong; Ross, Jenna; Yao, Huaiying; Nicol, Graeme W; Prosser, James I

    2014-09-01

    Autotrophic ammonia oxidation is performed by two distinct groups of microorganisms: ammonia-oxidising archaea (AOA) and ammonia-oxidising bacteria (AOB). AOA outnumber their bacterial counterparts in many soils, at times by several orders of magnitude, but relatively little is known of their physiology due to the lack of cultivated isolates. Although a number of AOA have been cultivated from soil, Nitrososphaera viennensis was the sole terrestrial AOA in pure culture and requires pyruvate for growth in the laboratory. Here, we describe isolation in pure culture and characterisation of two acidophilic terrestrial AOA representing the Candidatus genus Nitrosotalea and their responses to organic acids. Interestingly, despite their close phylogenetic relatedness, the two Nitrosotalea strains exhibited differences in physiological features, including specific growth rate, temperature preference and to an extent, response to organic compounds. In contrast to N. viennensis, both Nitrosotalea isolates were inhibited by pyruvate but their growth yield increased in the presence of oxaloacetate. This study demonstrates physiological diversity within AOA species and between different AOA genera. Different preferences for organic compounds potentially influence the favoured localisation of ammonia oxidisers within the soil and the structure of ammonia-oxidising communities in terrestrial ecosystems.

  14. Global oceanic emission of ammonia: Constraints from seawater and atmospheric observations

    NASA Astrophysics Data System (ADS)

    Paulot, F.; Jacob, D. J.; Johnson, M. T.; Bell, T. G.; Baker, A. R.; Keene, W. C.; Lima, I. D.; Doney, S. C.; Stock, C. A.

    2015-08-01

    Current global inventories of ammonia emissions identify the ocean as the largest natural source. This source depends on seawater pH, temperature, and the concentration of total seawater ammonia (NHx(sw)), which reflects a balance between remineralization of organic matter, uptake by plankton, and nitrification. Here we compare [NHx(sw)] from two global ocean biogeochemical models (BEC and COBALT) against extensive ocean observations. Simulated [NHx(sw)] are generally biased high. Improved simulation can be achieved in COBALT by increasing the plankton affinity for NHx within observed ranges. The resulting global ocean emissions is 2.5 TgN a-1, much lower than current literature values (7-23 TgN a-1), including the widely used Global Emissions InitiAtive (GEIA) inventory (8 TgN a-1). Such a weak ocean source implies that continental sources contribute more than half of atmospheric NHx over most of the ocean in the Northern Hemisphere. Ammonia emitted from oceanic sources is insufficient to neutralize sulfate aerosol acidity, consistent with observations. There is evidence over the Equatorial Pacific for a missing source of atmospheric ammonia that could be due to photolysis of marine organic nitrogen at the ocean surface or in the atmosphere. Accommodating this possible missing source yields a global ocean emission of ammonia in the range 2-5 TgN a-1, comparable in magnitude to other natural sources from open fires and soils.

  15. The purine nucleotide cycle. A pathway for ammonia production in the rat kidney.

    PubMed Central

    Bogusky, R T; Lowenstein, L M; Lowenstein, J M

    1976-01-01

    Particle-free extracts prepared from kidney cortex of rat catalyze the formation of ammonia via the purine nucleotide cycle. The cycle generates ammonia and fumarate from aspartate, using catalytic amounts of inosine monophosphate, adenylosuccinate, and adenosine monophosphate. The specific activities of the enzymes of the cycle are 1.27+/-0.27 nmol/mg protein per min (SE) for adenoylosuccinate synthetase, 1.38+/-0.16 for adenylosuccinase, and 44.0+/-3.3 for AMP deaminase. Compared with controls, extracts prepared from kidneys of rats fed ammonium chloride for 2 days show a 60% increase in adenylosuccinate synthetase and a threefold increase in adenylosuccinase activity, and a greater and more rapid synthesis of ammonia and adenine nucleotide from aspartate and inosine monophosphate. Extracts prepared from kidneys of rats fed a potassium-deficient diet show a twofold increase in adenylosuccinate synthetase and a threefold increase in adenylosuccinase activity. In such extracts the rate of synthesis of ammonia and adenine nucleotide from aspartate and inosine monophosphate is also increased. These results show that the reactions of the purine nucleotide cycle are present and can operate in extracts of kidney cortex. The operational capacity of the cycle is accelerated by ammonium chloride feeding and potassium depletion, conditions known to increase renal ammonia excretion. Extracts of kidney cortex convert inosine monophosphate to uric acid. This is prevented by addition of allopurinol of 1-pyrophosphoryl ribose 5-phosphate to the reaction mixture. PMID:821968

  16. Ammonia removal from raw manure digestate by means of a turbulent mixing stripping process.

    PubMed

    Limoli, Alice; Langone, Michela; Andreottola, Gianni

    2016-07-01

    In this study, ammonia stripping by means of a turbulent mixing process followed by pH neutralization was investigated as a simple and cost-effective ammonia removal technique to treat raw manure digestate. Batch tests conducted using CaO, NaOH and H2O2 to control pH and temperature and combinations thereof showed that sodium hydroxide was the most suitable chemical, as it is easy to handle, minimizes treatment time and costs, does not increase the solid content of the sludge and allows to easily control the stripping process. NaOH dosage mainly depended on buffering capacity rather than on total solid content. The analysis of the ammonia stripping process indicated that ammonia removal was strongly dependent on pH, and ammonia removal rate followed the pseudo-first-order kinetics. Total solid content slightly influenced TAN removal efficiency. When NaOH was applied to treat raw digestate at pH 10 and mean temperature of 23 ± 2 °C, TAN removal efficiency reached 88.7% after 24 h of turbulent mixing stripping, without reaching inhibitory salinity levels. Moreover, pH neutralization with sulfuric acid following the stripping process improved raw digestate dewaterability. PMID:27031295

  17. Electrospun Nanofibers from a Tricyanofuran-Based Molecular Switch for Colorimetric Recognition of Ammonia Gas.

    PubMed

    Khattab, Tawfik A; Abdelmoez, Sherif; Klapötke, Thomas M

    2016-03-14

    A chromophore based on tricyanofuran (TCF) with a hydrazone (H) recognition moiety was developed. Its molecular-switching performance is reversible and has differential sensitivity towards aqueous ammonia at comparable concentrations. Nanofibers were fabricated from the TCF-H chromophore by electrospinning. The film fabricated from these nanofibers functions as a solid-state optical chemosensor for probing ammonia vapor. Recognition of ammonia vapor occurs by proton transfer from the hydrazone fragment of the chromophore to the ammonia nitrogen atom and is facilitated by the strongly electron withdrawing TCF fragment. The TCF-H chromophore was added to a solution of poly(acrylic acid), which was electrospun to obtain a nanofibrous sensor device. The morphology of the nanofibrous sensor was determined by SEM, which showed that nanofibers with a diameter range of 200-450 nm formed a nonwoven mat. The resultant nanofibrous sensor showed very good sensitivity in ammonia-vapor detection. Furthermore, very good reversibility and short response time were also observed.

  18. Production of Melamine-Formaldehyde PCM Microcapsules with Ammonia Scavenger used for Residual Formaldehyde Reduction.

    PubMed

    Sumiga, Boštjan; Knez, Emil; Vrtačnik, Margareta; Ferk-Savec, Vesna; Starešinič, Marica; Boh, Bojana

    2011-03-01

    Paraffinic phase change materials (PCM) were microencapsulated by in situ polymerization of melamine-formaldehyde prepolymers. Partly methylated trimethylolmelamine was used as an aminoaldehyde prepolymer for the microcapsule wall, a styrene-maleic acid anhydride copolymer as an emulsifier and modifying agent, and ammonia as a scavenger for reducing residual formaldehyde. For the determination of residual formaldehyde in a ppm concentration range, EDANA and malachite green analytical methods were studied, and the EDANA 210.1-99 was applied for the determination of residual formaldehyde in 25 samples of microcapsules, produced in a 200-L reactor. A linear correlation was observed between the added ammonia scavenger concentration and the reduction of residual formaldehyde concentration. Compared with 0.45% (4500 ppm) formaldehyde in a non-treated microcapsule suspension, with ammonia scavenger concentrations 0.80, 0.90 and 1.35%, the concentration of residual formaldehyde dropped to 0.27, 0.20 and 0.09% (i.e. 2700, 2000 and 900 ppm), respectively. Morphological characterisation of microcapsules by SEM and microcapsule wall permeability measurements by gravimetry / mass loss at an elevated temperature (135 °C) suggested that ammonia positively contributed to the wall elasticity / durability, while microcapsules with no ammonia scavenger added tended to have more brittle walls, and were more prone to cracking.

  19. Acidosis-induced downregulation of hepatocyte mitochondrial aquaporin-8 and ureagenesis from ammonia.

    PubMed

    Molinas, Sara M; Soria, Leandro R; Marrone, Julieta; Danielli, Mauro; Trumper, Laura; Marinelli, Raúl A

    2015-08-01

    It has been proposed that, during metabolic acidosis, the liver downregulates mitochondrial ammonia detoxification via ureagenesis, a bicarbonate-consuming process. Since we previously demonstrated that hepatocyte mitochondrial aquaporin-8 channels (mtAQP8) facilitate the uptake of ammonia and its metabolism into urea, we studied whether mtAQP8 is involved in the liver adaptive response to acidosis. Primary cultured rat hepatocytes were adapted to acidosis by exposing them to culture medium at pH 7.0 for 40 h. Control cells were exposed to pH 7.4. Hepatocytes exposed to acid medium showed a decrease in mtAQP8 protein expression (-30%, p < 0.05). Ureagenesis from ammonia was assessed by incubating the cells with (15)N-labeled ammonia and measuring (15)N-labeled urea synthesis by nuclear magnetic resonance. Reduced ureagenesis was found in acidified hepatocytes (-31%, p < 0.05). In vivo studies in rats subjected to 7 days acidosis also showed decreased protein expression of hepatic mtAQP8 (-50%, p < 0.05) and reduced liver urea content (-35%; p < 0.05). In conclusion, our in vitro and in vivo data suggest that hepatic mtAQP8 expression is downregulated in acidosis, a mechanism that may contribute to decreased ureagenesis from ammonia in response to acidosis.

  20. Hydrogen generation from deliquescence of ammonia borane using Ni-Co/r-GO catalyst

    NASA Astrophysics Data System (ADS)

    Chou, Chang-Chen; Chen, Bing-Hung

    2015-10-01

    Hydrogen generation from the catalyzed deliquescence/hydrolysis of ammonia borane (AB) using the Ni-Co catalyst supported on the graphene oxide (Ni-Co/r-GO catalyst) under the conditions of limited water supply was studied with the molar feed ratio of water to ammonia borane (denoted as H2O/AB) at 2.02, 3.97 and 5.93, respectively. The conversion efficiency of ammonia borane to hydrogen was estimated both from the cumulative volume of the hydrogen gas generated and the conversion of boron chemistry in the hydrolysates analyzed by the solid-state 11B NMR. The conversion efficiency of ammonia borane could reach nearly 100% under excess water dosage, that is, H2O/AB = 3.97 and 5.93. Notably, the hydrogen storage capacity could reach as high as 6.5 wt.% in the case with H2O/AB = 2.02. The hydrolysates of ammonia borane in the presence of Ni-Co/r-GO catalyst were mainly the mixture of boric acid and metaborate according to XRD, FT-IR and solid-state 11B NMR analyses.

  1. Ammonia uptake by phytoplankton and limnological studies of Mountain Lake, Virginia

    SciTech Connect

    Parson, J.J.

    1988-01-01

    The first comprehensive year-round investigation of Mountain Lake, Virginia since 1970-71 was begun in March 1985 and continued through November 1987. Whereas inorganic nitrogen, orthophosphate, Secchi disc transparency, and primary productivity continue to suggest an oligotrophic condition, important limnological changes are indicated by the greater seasonal hypolimnetic oxygen depletion and extractable chlorophyll a which at times approach mesotrophic levels. In addition, the decrease in alkalinity, the increase in sulfate levels, and the increase in pH fluctuations compared to the past, suggest that Mountain Lake is susceptible to damage or change by acid rain and perhaps other perturbations that effect pH alkalinity or hardness. Changes were also noted in phytoplankton composition. Studies of ammonia uptake by the phytoplankton, using the ammonia analog ({sup 14}C)methylamine (MeA), revealed that during thermal stratification, phytoplankton succession was related to rapid ammonia uptake. Each successive phytoplankton community had significantly higher Vmax values for ammonia (methylamine) until midsummer when ammonia-nitrogen levels were at a seasonal low.

  2. Wastewater effluent impacts ammonia-oxidizing prokaryotes of the Grand River, Canada.

    PubMed

    Sonthiphand, Puntipar; Cejudo, Eduardo; Schiff, Sherry L; Neufeld, Josh D

    2013-12-01

    The Grand River (Ontario, Canada) is impacted by wastewater treatment plants (WWTPs) that release ammonia (NH3 and NH4+) into the river. In-river microbial communities help transform this ammonia into more oxidized compounds (e.g., NO3- or N2), although the spatial distribution and relative abundance of freshwater autotrophic ammonia-oxidizing prokaryotes (AOP) are not well characterized. This study investigated freshwater N cycling within the Grand River, focusing on sediment and water columns, both inside and outside a WWTP effluent plume. The diversity, relative abundance, and nitrification activity of AOP were investigated by denaturing gradient gel electrophoresis (DGGE), quantitative real-time PCR (qPCR), and reverse transcriptase qPCR (RT-qPCR), targeting both 16S rRNA and functional genes, together with activity assays. The analysis of bacterial 16S rRNA gene fingerprints showed that the WWTP effluent strongly affected autochthonous bacterial patterns in the water column but not those associated with sediment nucleic acids. Molecular and activity data demonstrated that ammonia-oxidizing archaea (AOA) were numerically and metabolically dominant in samples taken from outside the WWTP plume, whereas ammonia-oxidizing bacteria (AOB) dominated numerically within the WWTP effluent plume. Potential nitrification rate measurements supported the dominance of AOB activity in downstream sediment. Anaerobic ammonia-oxidizing (anammox) bacteria were detected primarily in sediment nucleic acids. In-river AOA patterns were completely distinct from effluent AOA patterns. This study demonstrates the importance of combined molecular and activity-based studies for disentangling molecular signatures of wastewater effluent from autochthonous prokaryotic communities.

  3. Ammonia threshold for inhibition of anaerobic digestion of thin stillage and the importance of organic loading rate.

    PubMed

    Moestedt, Jan; Müller, Bettina; Westerholm, Maria; Schnürer, Anna

    2016-03-01

    Biogas production from nitrogen-rich feedstock results in release of ammonia (NH3), causing inhibition of the microbial process. The reported threshold ammonia value for stable biogas production varies greatly between studies, probably because of differences in operating conditions. Moreover, it is often difficult to separate the effect of ammonia inhibition from that of organic loading rate (OLR), as these two factors are often interrelated. This study attempted to distinguish the effects of ammonia and OLR by analysis of two laboratory-scale biogas reactors operating with thin stillage and subjected to an increase in free ammonia (from 0.30 to 1.1 g L(-1)) either by addition of an external nitrogen source (urea) or by increasing the OLR (3.2-6.0 g volatile solids L(-1) d(-1)). The results showed that ammonia concentration was detrimental for process performance, with the threshold for stability in both processes identified as being about 1 g NH3-N L(-1), irrespective of OLR. Analysis of the methanogenic community showed limited differences between the two reactors on order level and a clear increase in the abundance of Methanomicrobiales, particularly Methanoculleus sp., in response to increasing ammonia concentration. Further comprehensive molecular analysis revealed that diverse Methanoculleus species dominated in the reactors at a given ammonia level at different OLR. The acetogenic community was clearly affected by both ammonia concentration and OLR, suggesting that the volatile fatty acid load in relation to the higher OLR was important for the dynamics of this community. PMID:26686366

  4. The Ammonia-Hydrogen System under Pressure

    SciTech Connect

    Chidester, Bethany A; Strobel, Timothy A

    2012-01-20

    Binary mixtures of hydrogen and ammonia were compressed in diamond anvil cells to 15 GPa at room temperature over a range of compositions. The phase behavior was characterized using optical microscopy, Raman spectroscopy, and synchrotron X-ray diffraction. Below 1.2 GPa we observed two-phase coexistence between liquid ammonia and fluid hydrogen phases with limited solubility of hydrogen within the ammonia-rich phase. Complete immiscibility was observed subsequent to the freezing of ammonia phase III at 1.2 GPa, although hydrogen may become metastably trapped within the disordered face-centered-cubic lattice upon rapid solidification. For all compositions studied, the phase III to phase IV transition of ammonia occurred at ~3.8 GPa and hydrogen solidified at ~5.5 GPa, transition pressures equivalent to those observed for the pure components. A P-x phase diagram for the NH3-H2 system is proposed on the basis of these observations with implications for planetary ices, molecular compound formation, and possible hydrogen storage materials.

  5. Energy Efficient Operation of Ammonia Refrigeration Systems

    SciTech Connect

    Mohammed, Abdul Qayyum; Wenning, Thomas J; Sever, Franc; Kissock, Professor Kelly

    2013-01-01

    Ammonia refrigeration systems typically offer many energy efficiency opportunities because of their size and complexity. This paper develops a model for simulating single-stage ammonia refrigeration systems, describes common energy saving opportunities, and uses the model to quantify those opportunities. The simulation model uses data that are typically available during site visits to ammonia refrigeration plants and can be calibrated to actual consumption and performance data if available. Annual electricity consumption for a base-case ammonia refrigeration system is simulated. The model is then used to quantify energy savings for six specific energy efficiency opportunities; reduce refrigeration load, increase suction pressure, employ dual suction, decrease minimum head pressure set-point, increase evaporative condenser capacity, and reclaim heat. Methods and considerations for achieving each saving opportunity are discussed. The model captures synergistic effects that result when more than one component or parameter is changed. This methodology represents an effective method to model and quantify common energy saving opportunities in ammonia refrigeration systems. The results indicate the range of savings that might be expected from common energy efficiency opportunities.

  6. Ammonia stripping of biologically treated liquid manure.

    PubMed

    Alitalo, Anni; Kyrö, Aleksis; Aura, Erkki

    2012-01-01

    A prerequisite for efficient ammonia removal in air stripping is that the pH of the liquid to be stripped is sufficiently high. Swine manure pH is usually around 7. At pH 7 (at 20°C), only 0.4% of ammonium is in ammonia form, and it is necessary to raise the pH of swine slurry to achieve efficient ammonia removal. Because manure has a very high buffering capacity, large amounts of chemicals are needed to change the slurry pH. The present study showed that efficient air stripping of manure can be achieved with a small amount of chemicals and without strong bases like NaOH. Slurry was subjected to aerobic biological treatment to raise pH before stripping. This facilitated 8 to 32% ammonia removal without chemical treatment. The slurry was further subjected to repeated cycles of stripping with MgO and Ca(OH)(2) additions after the first and second strippings, respectively, to raise slurry pH in between the stripping cycles. After three consecutive stripping cycles, 59 to 86% of the original ammonium had been removed. It was shown that the reduction in buffer capacity of the slurry was due to ammonia and carbonate removal during the stripping cycles.

  7. Reactions of fluoroalkyl-. beta. -ketoesters with ammonia

    SciTech Connect

    Pashkevich, K.I.; Saloutin, V.I.; Fomin, A.N.; Rudaya, M.N.; Egorova, L.G.

    1987-01-20

    It has been found that ..beta..-ketoesters containing highly fluorinated substituents (CF/sub 3/, or H(CF/sub 2/)/sub 4/) react with ammonia to give ..beta..-aminocrotonate esters, or under severe conditions, ..beta..-ketoamides. The latter react with a tenfold excess of ammonia to give ..beta..-aminocrotonamides together with acetamide and fluorocarboxamides. Acetoacetic and 4,4-difluoroacetoacetic esters react with ammonia, irrespective of the reaction conditions, to give ..beta..-aminocrotonate and 4,4-difluoro-..beta..-aminocrotonate esters. Using DNMR and dipole moments, it has been shown that rotation of the amino group around the C-N bond in fluorinated ..beta..-aminocrotonate esters is restricted (..delta..Gnumber approx. 50 kJ/mole).

  8. Ammonia emission time profiles based on manure transport data improve ammonia modelling across north western Europe

    NASA Astrophysics Data System (ADS)

    Hendriks, C.; Kranenburg, R.; Kuenen, J. J. P.; Van den Bril, B.; Verguts, V.; Schaap, M.

    2016-04-01

    Accurate modelling of mitigation measures for nitrogen deposition and secondary inorganic aerosol (SIA) episodes requires a detailed representation of emission patterns from agriculture. In this study the meteorological influence on the temporal variability of ammonia emissions from livestock housing and application of manure and fertilizer are included in the chemistry transport model LOTOS-EUROS. For manure application, manure transport data from Flanders (Belgium) were used as a proxy to derive the emission variability. Using improved ammonia emission variability strongly improves model performance for ammonia, mainly by a better representation of the spring maximum. The impact on model performance for SIA was negligible as explained by the limited, ammonia rich region in which the emission variability was updated. The contribution of Flemish agriculture to modelled annual mean ammonia and SIA concentrations in Flanders were quantified at respectively 7-8 and 1-2 μg/m3. A scenario study was performed to investigate the effects of reducing ammonia emissions from manure application during PM episodes by 75%, yielding a maximum reduction in modelled SIA levels of 1-3 μg/m3 during episodes. Year-to-year emission variability and a soil module to explicitly model the emission process from manure and fertilizer application are needed to further improve the modelling of the ammonia budget.

  9. Hydrogen peroxide detoxification is a key mechanism for growth of ammonia-oxidizing archaea

    PubMed Central

    Kim, Jong-Geol; Park, Soo-Je; Sinninghe Damsté, Jaap S.; Schouten, Stefan; Rijpstra, W. Irene C.; Jung, Man-Young; Kim, So-Jeong; Gwak, Joo-Han; Hong, Heeji; Si, Ok-Ja; Lee, SangHoon; Madsen, Eugene L.; Rhee, Sung-Keun

    2016-01-01

    Ammonia-oxidizing archaea (AOA), that is, members of the Thaumarchaeota phylum, occur ubiquitously in the environment and are of major significance for global nitrogen cycling. However, controls on cell growth and organic carbon assimilation by AOA are poorly understood. We isolated an ammonia-oxidizing archaeon (designated strain DDS1) from seawater and used this organism to study the physiology of ammonia oxidation. These findings were confirmed using four additional Thaumarchaeota strains from both marine and terrestrial habitats. Ammonia oxidation by strain DDS1 was enhanced in coculture with other bacteria, as well as in artificial seawater media supplemented with α-keto acids (e.g., pyruvate, oxaloacetate). α-Keto acid-enhanced activity of AOA has previously been interpreted as evidence of mixotrophy. However, assays for heterotrophic growth indicated that incorporation of pyruvate into archaeal membrane lipids was negligible. Lipid carbon atoms were, instead, derived from dissolved inorganic carbon, indicating strict autotrophic growth. α-Keto acids spontaneously detoxify H2O2 via a nonenzymatic decarboxylation reaction, suggesting a role of α-keto acids as H2O2 scavengers. Indeed, agents that also scavenge H2O2, such as dimethylthiourea and catalase, replaced the α-keto acid requirement, enhancing growth of strain DDS1. In fact, in the absence of α-keto acids, strain DDS1 and other AOA isolates were shown to endogenously produce H2O2 (up to ∼4.5 μM), which was inhibitory to growth. Genomic analyses indicated catalase genes are largely absent in the AOA. Our results indicate that AOA broadly feature strict autotrophic nutrition and implicate H2O2 as an important factor determining the activity, evolution, and community ecology of AOA ecotypes. PMID:27339136

  10. Hydrogen peroxide detoxification is a key mechanism for growth of ammonia-oxidizing archaea.

    PubMed

    Kim, Jong-Geol; Park, Soo-Je; Sinninghe Damsté, Jaap S; Schouten, Stefan; Rijpstra, W Irene C; Jung, Man-Young; Kim, So-Jeong; Gwak, Joo-Han; Hong, Heeji; Si, Ok-Ja; Lee, SangHoon; Madsen, Eugene L; Rhee, Sung-Keun

    2016-07-12

    Ammonia-oxidizing archaea (AOA), that is, members of the Thaumarchaeota phylum, occur ubiquitously in the environment and are of major significance for global nitrogen cycling. However, controls on cell growth and organic carbon assimilation by AOA are poorly understood. We isolated an ammonia-oxidizing archaeon (designated strain DDS1) from seawater and used this organism to study the physiology of ammonia oxidation. These findings were confirmed using four additional Thaumarchaeota strains from both marine and terrestrial habitats. Ammonia oxidation by strain DDS1 was enhanced in coculture with other bacteria, as well as in artificial seawater media supplemented with α-keto acids (e.g., pyruvate, oxaloacetate). α-Keto acid-enhanced activity of AOA has previously been interpreted as evidence of mixotrophy. However, assays for heterotrophic growth indicated that incorporation of pyruvate into archaeal membrane lipids was negligible. Lipid carbon atoms were, instead, derived from dissolved inorganic carbon, indicating strict autotrophic growth. α-Keto acids spontaneously detoxify H2O2 via a nonenzymatic decarboxylation reaction, suggesting a role of α-keto acids as H2O2 scavengers. Indeed, agents that also scavenge H2O2, such as dimethylthiourea and catalase, replaced the α-keto acid requirement, enhancing growth of strain DDS1. In fact, in the absence of α-keto acids, strain DDS1 and other AOA isolates were shown to endogenously produce H2O2 (up to ∼4.5 μM), which was inhibitory to growth. Genomic analyses indicated catalase genes are largely absent in the AOA. Our results indicate that AOA broadly feature strict autotrophic nutrition and implicate H2O2 as an important factor determining the activity, evolution, and community ecology of AOA ecotypes. PMID:27339136

  11. Ammonia Results Review for Retained Gas Sampling

    SciTech Connect

    Mahoney, Lenna A.

    2000-09-20

    This report was prepared as part of a task supporting the deployment of the retained gas sampler (RGS) system in Flammable Gas Watch List Tanks. The emphasis of this report is on presenting supplemental information about the ammonia measurements resulting from retained gas sampling of Tanks 241-AW-101, A-101, AN-105, AN-104, AN-103, U-103, S-106, BY-101, BY-109, SX-106, AX-101, S-102, S-111, U-109, and SY-101. This information provides a better understanding of the accuracy of past RGS ammonia measurements, which will assist in determining flammable and toxicological hazards.

  12. Biochemistry of Ammonia Monoxygenase from Nitrosomonas

    SciTech Connect

    Alan Hooper

    2009-07-15

    Major results. 1. CytochromecM552, a protein in the electron transfer chain to ammonia monooxygenase. Purification, modeling of protein structure based on primary structure, characterization of 4 hemes by magnetic spectroscopy, potentiometry, ligand binding and turnover. Kim, H. J., ,Zatsman, et al. 2008). 2. Characterization of proteins which thought to be involved in the AMO reaction or to protect AMO from toxic nitrogenous intermediates such as NO. Nitrosocyanin is a protein present only in bacteria which catalyze the ammonia monoxygenase reaction (1). Cytochrome c P460 beta and cytochrome c’ beta.

  13. Ammonia Leaching: A New Approach of Copper Industry in Hydrometallurgical Processes

    NASA Astrophysics Data System (ADS)

    Radmehr, Vahid; Koleini, Seyed Mohammad Javad; Khalesi, Mohammad Reza; Tavakoli Mohammadi, Mohammad Reza

    2013-10-01

    Ammonia and ammonium salts have been recognized as effective leaching agents in hydrometallurgical processes due to low toxicity and cost, easy recovery and high selective recovery of metals. New research findings on considerable advantages of leaching by these agents and elimination of problems associated with acid leaching have resulted in a new approach in the world to this method. The investigations in this field indicate more frequent use of this method for extracting copper from ore and concentrate relative to other basic metals. In this paper, an attempt was made to describe the basis and different ammonia leaching methods and present the major research activities in this field for copper. Also latest findings and related novel processes have been presented. Comparisons including assessment of advantages and disadvantages of this method relative to acid leaching method, kinetic study of copper ammonia leaching and evaluation of Eh-pH diagrams in a system containing water and ammonia are other parts of this study. Finally, by describing the studies on copper extraction from the resulting pregnant solutions, the applicable extraction agents have been reviewed.

  14. Nitrogen potential recovery and concentration of ammonia from swine manure using electrodialysis coupled with air stripping.

    PubMed

    Ippersiel, D; Mondor, M; Lamarche, F; Tremblay, F; Dubreuil, J; Masse, L

    2012-03-01

    The practice of intensive animal production in certain areas has resulted in excessive manure production for the available regional land base. Consequently, there is a need to develop treatment technologies to recover the valuable nutrients that manure contains so that the resulting product can be transported and used as fertilizer on agricultural land. The project presented here used electrodialysis in a dilution/concentration configuration to transfer the manure ammonia in the diluate solution by electromigration to an adjacent solution separated by an ion-exchange membrane under the driving force of an electrical potential. Then, air stripping from the electrodialysis-obtained concentrate solution without pH modification was used to isolate the ammonia in an acidic solution. An optimal process operating voltage of 17.5 V was first determined on the basis of current efficiency and total energy consumption. During the process, the swine manure pH varied from 8.5 to 8.2, values favourable for NH(4)(+) electromigration. Total ammonia nitrogen reached 21,352 mg/L in the concentrate solution, representing approximately seven times the concentration in the swine manure. Further increases in concentration were limited by water transfer from the diluate solution due to electroosmosis and osmosis. Applying vacuum to the concentrate reservoir was found to be more efficient than direct concentrate solution aeration for NH(3) recuperation in the acid trap, given that the ammonia recuperated under vacuum represented 14.5% of the theoretical value of the NH(3) present in the concentrate solution as compared to 6.2% for aeration. However, an excessively low concentrate solution pH (8.6-8.3) limited NH(3)volatilization toward the acid trap. These results suggest that the concentrate solution pH needs to be raised to promote the volatile NH(3) form of total ammonia nitrogen.

  15. A high-resolution ammonia emission inventory in China

    NASA Astrophysics Data System (ADS)

    Huang, Xin; Song, Yu; Li, Mengmeng; Li, Jianfeng; Huo, Qing; Cai, Xuhui; Zhu, Tong; Hu, Min; Zhang, Hongsheng

    2012-03-01

    The existence of gas-phase ammonia (NH3) in the atmosphere and its interaction with other trace chemical species could have a substantial impact on tropospheric chemistry and global climate change. China is a large agricultural country with an enormous animal population, tremendous nitrogen fertilizer consumption and, consequently, a large emission of NH3. Despite the importance of NH3 in the global nitrogen (N) cycle, considerable inaccuracies and uncertainty exist regarding its emission in China. In this study, a comprehensive NH3 emission inventory was compiled for China on a 1 km × 1 km grid, which is suitable for input to atmospheric models. We attempted to estimate NH3 emissions accurately by taking into consideration as many native experiment results as possible and parameterizing the emission factors (EFs) by the ambient temperature, soil acidity and other factors. The total NH3emission in China was approximately 9.8 Tg in 2006. The emission sources considered included livestock excreta (5.3 Tg), fertilizer application (3.2 Tg), agricultural soil (0.2 Tg), nitrogen-fixing plants (0.05 Tg), crop residue compost (0.3 Tg), biomass burning (0.1 Tg), urine from rural populations (0.2 Tg), chemical industry (0.2 Tg), waste disposal (0.1 Tg) and traffic (0.1 Tg). The regions with the highest emission rates are located in Central and Southwest China. Seasonally, the peak ammonia emissions occur in spring and summer.

  16. Ammonia oxidation is not required for growth of Group 1.1c soil Thaumarchaeota

    PubMed Central

    Weber, Eva B.; Lehtovirta-Morley, Laura E.; Prosser, James I.; Gubry-Rangin, Cécile

    2015-01-01

    Thaumarchaeota are among the most abundant organisms on Earth and are ubiquitous. Within this phylum, all cultivated representatives of Group 1.1a and Group 1.1b Thaumarchaeota are ammonia oxidizers, and play a key role in the nitrogen cycle. While Group 1.1c is phylogenetically closely related to the ammonia-oxidizing Thaumarchaeota and is abundant in acidic forest soils, nothing is known about its physiology or ecosystem function. The goal of this study was to perform in situ physiological characterization of Group 1.1c Thaumarchaeota by determining conditions that favour their growth in soil. Several acidic grassland, birch and pine tree forest soils were sampled and those with the highest Group 1.1c 16S rRNA gene abundance were incubated in microcosms to determine optimal growth temperature, ammonia oxidation and growth on several organic compounds. Growth of Group 1.1c Thaumarchaeota, assessed by qPCR of Group 1.1c 16S rRNA genes, occurred in soil, optimally at 30°C, but was not associated with ammonia oxidation and the functional gene amoA could not be detected. Growth was also stimulated by addition of organic nitrogen compounds (glutamate and casamino acids) but not when supplemented with organic carbon alone. This is the first evidence for non-ammonia oxidation associated growth of Thaumarchaeota in soil. PMID:25764563

  17. Accuracy of cuticular resistance parameterizations in ammonia dry deposition models

    NASA Astrophysics Data System (ADS)

    Schrader, Frederik; Brümmer, Christian; Richter, Undine; Fléchard, Chris; Wichink Kruit, Roy; Erisman, Jan Willem

    2016-04-01

    Accurate representation of total reactive nitrogen (Nr) exchange between ecosystems and the atmosphere is a crucial part of modern air quality models. However, bi-directional exchange of ammonia (NH3), the dominant Nr species in agricultural landscapes, still poses a major source of uncertainty in these models, where especially the treatment of non-stomatal pathways (e.g. exchange with wet leaf surfaces or the ground layer) can be challenging. While complex dynamic leaf surface chemistry models have been shown to successfully reproduce measured ammonia fluxes on the field scale, computational restraints and the lack of necessary input data have so far limited their application in larger scale simulations. A variety of different approaches to modelling dry deposition to leaf surfaces with simplified steady-state parameterizations have therefore arisen in the recent literature. We present a performance assessment of selected cuticular resistance parameterizations by comparing them with ammonia deposition measurements by means of eddy covariance (EC) and the aerodynamic gradient method (AGM) at a number of semi-natural and grassland sites in Europe. First results indicate that using a state-of-the-art uni-directional approach tends to overestimate and using a bi-directional cuticular compensation point approach tends to underestimate cuticular resistance in some cases, consequently leading to systematic errors in the resulting flux estimates. Using the uni-directional model, situations where low ratios of total atmospheric acids to NH3 concentration occur lead to fairly high minimum cuticular resistances, limiting predicted downward fluxes in conditions usually favouring deposition. On the other hand, the bi-directional model used here features a seasonal cycle of external leaf surface emission potentials that can lead to comparably low effective resistance estimates under warm and wet conditions, when in practice an expected increase in the compensation point due to

  18. 46 CFR 151.50-32 - Ammonia, anhydrous.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... enclosed anhydrous ammonia tanks complies with the following chemical and physical properties: (1) Boiling point above 125 °F atmospheric pressure. (2) Inert to ammonia at 100 °F at atmospheric pressure....

  19. 46 CFR 151.50-32 - Ammonia, anhydrous.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... enclosed anhydrous ammonia tanks complies with the following chemical and physical properties: (1) Boiling point above 125 °F atmospheric pressure. (2) Inert to ammonia at 100 °F at atmospheric pressure....

  20. 46 CFR 151.50-32 - Ammonia, anhydrous.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... enclosed anhydrous ammonia tanks complies with the following chemical and physical properties: (1) Boiling point above 125 °F atmospheric pressure. (2) Inert to ammonia at 100 °F at atmospheric pressure....

  1. Ammonia volatilisation in waste stabilisation ponds: a cascade of misinterpretations?

    PubMed

    Camargo Valero, M A; Mara, D D

    2010-01-01

    Ammonia volatilisation has generally been reported as, or assumed to be, the main nitrogen removal mechanism in waste stabilisation ponds (WSP). Nitrogen removal via ammonia volatilisation is based on two observations: (a) in-pond pH values can reach high values (>9, even >10), so increasing the proportion of the total ammonia present as the un-ionized form or free ammonia (NH(3)); and (b) in-pond temperatures can also be high, so improving the mass transfer rate of free ammonia to the atmosphere. Consequently, one of the most widely accepted models for ammonia removal in WSP is that reported by Pano & Middlebrooks in 1982, which was developed to reflect the occurrence of these two observations. This work reports how simple mathematical models for ammonia volatilisation in WSP, in spite of the possibility of their giving good predictions, may not accurately describe the main pathways and mechanisms involved in ammonia removal in WSP.

  2. Comparison of low-cost methods for measuring ammonia volatilization

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nitrogen fertilizer application to improve crop production is increasing worldwide, and subsequent nitrogen losses via ammonia emissions generate undesirable economic and environmental consequences. Thus, low cost and practical methods to quantify ammonia emissions are essential for the development ...

  3. Ammonia volatilisation in waste stabilisation ponds: a cascade of misinterpretations?

    PubMed

    Camargo Valero, M A; Mara, D D

    2010-01-01

    Ammonia volatilisation has generally been reported as, or assumed to be, the main nitrogen removal mechanism in waste stabilisation ponds (WSP). Nitrogen removal via ammonia volatilisation is based on two observations: (a) in-pond pH values can reach high values (>9, even >10), so increasing the proportion of the total ammonia present as the un-ionized form or free ammonia (NH(3)); and (b) in-pond temperatures can also be high, so improving the mass transfer rate of free ammonia to the atmosphere. Consequently, one of the most widely accepted models for ammonia removal in WSP is that reported by Pano & Middlebrooks in 1982, which was developed to reflect the occurrence of these two observations. This work reports how simple mathematical models for ammonia volatilisation in WSP, in spite of the possibility of their giving good predictions, may not accurately describe the main pathways and mechanisms involved in ammonia removal in WSP. PMID:20150690

  4. Ammonia as a Potential Neurotoxic Factor in Alzheimer's Disease

    PubMed Central

    Adlimoghaddam, Aida; Sabbir, Mohammad G.; Albensi, Benedict C.

    2016-01-01

    Ammonia is known to be a potent neurotoxin that causes severe negative effects on the central nervous system. Excessive ammonia levels have been detected in the brain of patients with neurological disorders such as Alzheimer disease (AD). Therefore, ammonia could be a factor contributing to the progression of AD. In this review, we provide an introduction to the toxicity of ammonia and putative ammonia transport proteins. We also hypothesize how ammonia may be linked to AD. Additionally, we discuss the evidence that support the hypothesis that ammonia is a key factor contributing to AD progression. Lastly, we summarize the old and new experimental evidence that focuses on energy metabolism, mitochondrial function, inflammatory responses, excitatory glutamatergic, and GABAergic neurotransmission, and memory in support of our ammonia-related hypotheses of AD. PMID:27551259

  5. Ammonia as a Potential Neurotoxic Factor in Alzheimer's Disease.

    PubMed

    Adlimoghaddam, Aida; Sabbir, Mohammad G; Albensi, Benedict C

    2016-01-01

    Ammonia is known to be a potent neurotoxin that causes severe negative effects on the central nervous system. Excessive ammonia levels have been detected in the brain of patients with neurological disorders such as Alzheimer disease (AD). Therefore, ammonia could be a factor contributing to the progression of AD. In this review, we provide an introduction to the toxicity of ammonia and putative ammonia transport proteins. We also hypothesize how ammonia may be linked to AD. Additionally, we discuss the evidence that support the hypothesis that ammonia is a key factor contributing to AD progression. Lastly, we summarize the old and new experimental evidence that focuses on energy metabolism, mitochondrial function, inflammatory responses, excitatory glutamatergic, and GABAergic neurotransmission, and memory in support of our ammonia-related hypotheses of AD. PMID:27551259

  6. Acidifier application rate impacts on ammonia emissions from US roaster chicken houses

    NASA Astrophysics Data System (ADS)

    Shah, Sanjay B.; Grimes, Jesse L.; Oviedo-Rondón, Edgar O.; Westerman, Philip W.

    2014-08-01

    Due to its potential environmental and public health impacts, emissions of ammonia (NH3) as well as several other gases from US livestock farms may be regulated. Broiler houses are important sources of NH3 emissions. However, there are no emissions data from roaster (8-12 wk old broilers, ˜4 kg ea.) houses. Producers treat the litter in broiler houses with acidifiers, such as sodium bisulfate (SBS, NaHSO4) to reduce ammonia production and protect bird health. However, there is very little data on the effect of acidifiers, particularly at high application rates on ammonia emissions. The impact of different SBS application rates [High (0.95-1.46 kg m-2, whole house), Medium (0.73 kg m-2, whole house), Low (0.37-0.49 kg m-2, whole house), and Control (0.37-0.49 kg m-2, brood chamber)] on ammonia emissions was evaluated in commercial roaster houses over 22 months spanning eight flocks. Ammonia emission from each fan was measured with an acid scrubber that operated only when the fan operated. Emissions were calculated using >95% measured data with the rest being estimated using robust methods. Exhaust ammonia-N concentrations were inversely correlated with the SBS application rates. Emission rates on animal unit (AU, where 1 AU = 500 kg live-mass) basis (ER, g d-1 AU-1) were reduced by 27, 13, and 5%, respectively, in the High, Medium, and Low treatments vs. the Control treatment (mean: 100 g d-1 AU-1, range: 86-114 g d-1 AU-1). Emission rates for the Control treatment measured in this study on roasters were mostly higher than ERs in the literature. Differences in ERs are not only due to diet, environmental and management conditions, but also due to measurement methods.

  7. Modulation of sheep ruminal urea transport by ammonia and pH.

    PubMed

    Lu, Zhongyan; Stumpff, Friederike; Deiner, Carolin; Rosendahl, Julia; Braun, Hannah; Abdoun, Khalid; Aschenbach, Jörg R; Martens, Holger

    2014-09-01

    Ruminal fermentation products such as short-chain fatty acids (SCFA) and CO2 acutely stimulate urea transport across the ruminal epithelium in vivo, whereas ammonia has inhibitory effects. Uptake and signaling pathways remain obscure. The ruminal expression of SLC14a1 (UT-B) was studied using polymerase chain reaction (PCR). The functional short-term effects of ammonia on cytosolic pH (pHi) and ruminal urea transport across native epithelia were investigated using pH-sensitive microelectrodes and via flux measurements in Ussing chambers. Two variants (UT-B1 and UT-B2) could be fully sequenced from ovine ruminal cDNA. Functionally, transport was passive and modulated by luminal pH in the presence of SCFA and CO2, rising in response to luminal acidification to a peak value at pH 5.8 and dropping with further acidification, resulting in a bell-shaped curve. Presence of ammonia reduced the amplitude, but not the shape of the relationship between urea flux and pH, so that urea flux remained maximal at pH 5.8. Effects of ammonia were concentration dependent, with saturation at 5 mmol/l. Clamping the transepithelial potential altered the inhibitory potential of ammonia on urea flux. Ammonia depolarized the apical membrane and acidified pHi, suggesting that, at physiological pH (< 7), uptake of NH4 (+) into the cytosol may be a key signaling event regulating ruminal urea transport. We conclude that transport of urea across the ruminal epithelium involves proteins subject to rapid modulation by manipulations that alter pHi and the cytosolic concentration of NH4 (+). Implications for epithelial and ruminal homeostasis are discussed.

  8. Bioaugmentation of Syntrophic Acetate-Oxidizing Culture in Biogas Reactors Exposed to Increasing Levels of Ammonia

    PubMed Central

    Westerholm, Maria; Levén, Lotta

    2012-01-01

    The importance of syntrophic acetate oxidation for process stability in methanogenic systems operating at high ammonia concentrations has previously been emphasized. In this study we investigated bioaugmentation of syntrophic acetate-oxidizing (SAO) cultures as a possible method for decreasing the adaptation period of biogas reactors operating at gradually increased ammonia concentrations (1.5 to 11 g NH4+-N/liter). Whole stillage and cattle manure were codigested semicontinuously for about 460 days in four mesophilic anaerobic laboratory-scale reactors, and a fixed volume of SAO culture was added daily to two of the reactors. Reactor performance was evaluated in terms of biogas productivity, methane content, pH, alkalinity, and volatile fatty acid (VFA) content. The decomposition pathway of acetate was analyzed by isotopic tracer experiments, and population dynamics were monitored by quantitative PCR analyses. A shift in dominance from aceticlastic methanogenesis to SAO occurred simultaneously in all reactors, indicating no influence by bioaugmentation on the prevailing pathway. Higher abundances of Clostridium ultunense and Tepidanaerobacter acetatoxydans were associated with bioaugmentation, but no influence on Syntrophaceticus schinkii or the methanogenic population was distinguished. Overloading or accumulation of VFA did not cause notable dynamic effects on the population. Instead, the ammonia concentration had a substantial impact on the abundance level of the microorganisms surveyed. The addition of SAO culture did not affect process performance or stability against ammonia inhibition, and all four reactors deteriorated at high ammonia concentrations. Consequently, these findings further demonstrate the strong influence of ammonia on the methane-producing consortia and on the representative methanization pathway in mesophilic biogas reactors. PMID:22923397

  9. Measuring ammonia concentrations and emissions from agricultural land and liquid surfaces: a review.

    PubMed

    Shah, Sanjay B; Westerman, Philip W; Arogo, Jactone

    2006-07-01

    Aerial ammonia concentrations (Cg) are measured using acid scrubbers, filter packs, denuders, or optical methods. Using Cg and wind speed or airflow rate, ammonia emission rate or flux can be directly estimated using enclosures or micrometeorological methods. Using nitrogen (N) recovery is not recommended, mainly because the different gaseous N components cannot be separated. Although low cost and replicable, chambers modify environmental conditions and are suitable only for comparing treatments. Wind tunnels do not modify environmental conditions as much as chambers, but they may not be appropriate for determining ammonia fluxes; however, they can be used to compare emissions and test models. Larger wind tunnels that also simulate natural wind profiles may be more useful for comparing treatments than micrometeorological methods because the latter require larger plots and are, thus, difficult to replicate. For determining absolute ammonia flux, the micrometeorological methods are the most suitable because they are nonintrusive. For use with micrometeorological methods, both the passive denuders and optical methods give comparable accuracies, although the latter give real-time Cg but at a higher cost. The passive denuder is wind weighted and also costs less than forced-air Cg measurement methods, but it requires calibration. When ammonia contamination during sample preparation and handling is a concern and separating the gas-phase ammonia and aerosol ammonium is not required, the scrubber is preferred over the passive denuder. The photothermal interferometer, because of its low detection limit and robustness, may hold potential for use in agriculture, but it requires evaluation. With its simpler theoretical basis and fewer restrictions, the integrated horizontal flux (IHF) method is preferable over other micrometeorological methods, particularly for lagoons, where berms and land-lagoon boundaries modify wind flow and flux gradients. With uniform wind flow, the ZINST

  10. Removal of ammonia from tarry water using a tubular furnace

    SciTech Connect

    V.V. Grabko; V.A. Kofanova; V.M. Li; M.A. Solov'ev

    2009-07-15

    An ammonia-processing system without the use of live steam from OAO Alchevskkoks plant's supply network is considered. Steam obtained from the wastewater that leaves the ammonia column is used to process the excess tarry water, with the release of volatile ammonia.

  11. Comparison of ammonia emissions determined using different sampling methods

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dynamic, flow-through flux chambers are sometimes used to estimate ammonia emissions from livestock operations; however, ammonia emissions from the surfaces are affected by many factors which can be affected by the chamber. Ammonia emissions estimated using environmental flow-through chambers may be...

  12. Management Options for Reducing Ammonia Emissions from Poultry Litter

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ammonia emissions from poultry litter not only result in air pollution; high levels of ammonia in poultry houses cause poor bird performance, increase the susceptibility of birds to viral diseases, and negatively impact human health. Although ammonia emissions are a concern, few cost-effective best ...

  13. Resurfacing of Titan by Ammonia-Water Cryomagma

    NASA Astrophysics Data System (ADS)

    Mitri, G.; Showman, A. P.; Lunine, J. I.; Lopes, R.

    2006-03-01

    We propose mechanism for cryovolcanic processes on Titan involving bottom crevasse formation in an ice shell floating on an ammonia-water ocean, transport of ammonia-water pockets to the base of the stagnant lid by convective motions in the ice, and refreezing of chambers of ammonia-water.

  14. 46 CFR 151.50-32 - Ammonia, anhydrous.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... BULK LIQUID HAZARDOUS MATERIAL CARGOES Special Requirements § 151.50-32 Ammonia, anhydrous. (a) The anhydrous ammonia tanks may be installed in the bulk liquid cargo tanks provided the liquid surrounding the enclosed anhydrous ammonia tanks complies with the following chemical and physical properties: (1)...

  15. 46 CFR 151.50-32 - Ammonia, anhydrous.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... BULK LIQUID HAZARDOUS MATERIAL CARGOES Special Requirements § 151.50-32 Ammonia, anhydrous. (a) The anhydrous ammonia tanks may be installed in the bulk liquid cargo tanks provided the liquid surrounding the enclosed anhydrous ammonia tanks complies with the following chemical and physical properties: (1)...

  16. Archaea and Bacteria Acclimate to High Total Ammonia in a Methanogenic Reactor Treating Swine Waste

    PubMed Central

    Parameswaran, Prathap; Rittmann, Bruce E.

    2016-01-01

    Inhibition by ammonium at concentrations above 1000 mgN/L is known to harm the methanogenesis phase of anaerobic digestion. We anaerobically digested swine waste and achieved steady state COD-removal efficiency of around 52% with no fatty-acid or H2 accumulation. As the anaerobic microbial community adapted to the gradual increase of total ammonia-N (NH3-N) from 890 ± 295 to 2040 ± 30 mg/L, the Bacterial and Archaeal communities became less diverse. Phylotypes most closely related to hydrogenotrophic Methanoculleus (36.4%) and Methanobrevibacter (11.6%), along with acetoclastic Methanosaeta (29.3%), became the most abundant Archaeal sequences during acclimation. This was accompanied by a sharp increase in the relative abundances of phylotypes most closely related to acetogens and fatty-acid producers (Clostridium, Coprococcus, and Sphaerochaeta) and syntrophic fatty-acid Bacteria (Syntrophomonas, Clostridium, Clostridiaceae species, and Cloacamonaceae species) that have metabolic capabilities for butyrate and propionate fermentation, as well as for reverse acetogenesis. Our results provide evidence countering a prevailing theory that acetoclastic methanogens are selectively inhibited when the total ammonia-N concentration is greater than ~1000 mgN/L. Instead, acetoclastic and hydrogenotrophic methanogens coexisted in the presence of total ammonia-N of ~2000 mgN/L by establishing syntrophic relationships with fatty-acid fermenters, as well as homoacetogens able to carry out forward and reverse acetogenesis. PMID:27725793

  17. Ammonia fixation by humic substances: A nitrogen-15 and carbon-13 NMR study

    USGS Publications Warehouse

    Thorn, K.A.; Mikita, M.A.

    1992-01-01

    The process of ammonia fixation has been studied in three well characterized and structurally diverse fulvic and humic acid samples. The Suwannee River fulvic acid, and the IHSS peat and leonardite humic acids, were reacted with 15N-labelled ammonium hydroxide, and analyzed by liquid phase 15N NMR spectrometry. Elemental analyses and liquid phase 13C NMR spectra also were recorded on the samples before and after reaction with ammonium hydroxide. The largest increase in percent nitrogen occurred with the Suwannee River fulvic acid, which had a nitrogen content of 0.88% before fixation and 3.17% after fixation. The 15N NMR spectra revealed that ammonia reacted similarly with all three samples, indicating that the functional groups which react with ammonia exist in structural configurations common to all three samples. The majority of nitrogcn incorporated into the samples appears to be in the form of indole and pyrrole nitrogen, followed by pyridine, pyrazine, amide and aminohydroquinone nitrogen. Chemical changes in the individual samples upon fixation could not be discerned from the 13C NMR spectra.

  18. Ammonia in comet P/Halley

    NASA Technical Reports Server (NTRS)

    Meier, R.; Eberhardt, P.; Krankowsky, D.; Hodges, R. R.

    1994-01-01

    In comet P/Halley the abundances of ammonia relative to water reported in the literature differ by about one order of magnitude from roughly 0.1% up to 2%. Different observational techniques seem to have inherent systematic errors. Using the ion mass channels m/q = 19 amu/e, 18 amu/e and 17 amu/e of the Neutral Mass Spectrometer experiment aboard the spacecraft Giotto, we derive a production rate of ammonia of (1.5(sub -0.7)(sup +0.5))% relative to water. Inside the contact surface we can explain our data by a nuclear source only. The uncertainty in our abundance of ammonia is primarily a result of uncertainties in some key reaction coefficients. We discuss in detail these reactions and the range of error indicated results from extreme assumptions in the rate coefficients. From our data, even in the worst case, we can exclude the ammonia abundance to be only of the order of a few per mill.

  19. 21 CFR 573.180 - Anhydrous ammonia.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... to corn plant material and thoroughly blended prior to ensiling. It is used or intended for use as a... daily in shelled corn; and a warning not to use additional trace mineral supplementation with treated silage. (2)(i) The food additive anhydrous ammonia is applied directly to corn plant material for use...

  20. Radiation Chemistry in Ammonia-Water Ices

    NASA Technical Reports Server (NTRS)

    Loeffler, M. J.; Raut, U.; Baragiola, R. A.

    2010-01-01

    We studied the effects of 100 keV proton irradiation on films of ammonia-water mixtures between 20 and 120 K. Irradiation destroys ammonia, leading to the formation and trapping of H2, N2 NO, and N2O, the formation of cavities containing radiolytic gases, and ejection of molecules by sputtering. Using infrared spectroscopy, we show that at all temperatures the destruction of ammonia is substantial, but at higher temperatures (120 K), it is nearly complete (approximately 97% destroyed) after a fluence of 10(exp 16) ions per square centimeter. Using mass spectroscopy and microbalance gravimetry, we measure the sputtering yield of our sample and the main components of the sputtered flux. We find that the sputtering yield depends on fluence. At low temperatures, the yield is very low initially and increases quadratically with fluence, while at 120 K the yield is constant and higher initially. The increase in the sputtering yield with fluence is explained by the formation and trapping of the ammonia decay products, N2 and H2 which are seen to be ejected from the ice at all temperatures.

  1. Sensitivity of Mytilus galloprovincialis larvae to ammonia

    SciTech Connect

    Gardiner, W.W.; Antrim, L.D.; Word, J.Q.

    1994-12-31

    Free ammonia is a constituent of some marine effluents and sediments. The authors evaluated the sensitivity of the larval stage of the marine bivalve, Mytilus galloprovincialis, to concentrations of ammonium sulfate, as well as to suspended-particulate-phase (SPP) preparations of marine sediments and petroleum-based marine effluents. Mytilus larvae are commonly used test organisms because of their sensitivity to toxicants and their use in evaluation of water-column impacts of dredged material disposal. Ammonia-only EC{sub 50} values were between 3 mg/L NH{sub 3} and 8 mg/L NH{sub 3}; LC{sub 50} values ranged from 66 mg/L NH{sub 3} to 100 mg/L NH{sub 3}. Abnormalities included exogastrulation and arrested development at early gastrulation. The EC{sub 50} values for ammonia in SPP and effluents were within similar ranges, which indicates that ammonia may contribute significantly to toxicity of these materials. Exposure of larvae during different developmental stages and time periods will also be discussed.

  2. USDA-EPA Collaborative Ammonia Research

    EPA Science Inventory

    In 2014, a work group was formed between USDA and EPA to facilitate information exchange on ammonia emissions from agriculture, air quality impacts and emission mitigation options and to identify opportunities for collaboration. This document provides background on the work grou...

  3. Ammonia release method for depositing metal oxides

    DOEpatents

    Silver, G.L.; Martin, F.S.

    1994-12-13

    A method is described for depositing metal oxides on substrates which is indifferent to the electrochemical properties of the substrates and which comprises forming ammine complexes containing metal ions and thereafter effecting removal of ammonia from the ammine complexes so as to permit slow precipitation and deposition of metal oxide on the substrates. 1 figure.

  4. Ammonia release method for depositing metal oxides

    DOEpatents

    Silver, Gary L.; Martin, Frank S.

    1994-12-13

    A method of depositing metal oxides on substrates which is indifferent to the electrochemical properties of the substrates and which comprises forming ammine complexes containing metal ions and thereafter effecting removal of ammonia from the ammine complexes so as to permit slow precipitation and deposition of metal oxide on the substrates.

  5. Subsurface manure application to reduce ammonia emissions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Incorporation into soil is generally recommended to reduce ammonia volatilization and nutrient runoff following land application of manures. A range of subsurface applicators are available for manure incorporation with minimal soil disturbance in reduced tillage systems, but none have been widely a...

  6. Ammonia release method for depositing metal oxides

    SciTech Connect

    Silver, G.L.; Martin, F.S.

    1993-12-31

    A method of depositing metal oxides on substrates which is indifferent to the electrochemical properties of the substrates and which comprises forming ammine complexes containing metal ions and thereafter effecting removal of ammonia from the ammine complexes so as to permit slow precipitation and deposition of metal oxide on the substrates.

  7. The origin of mouth-exhaled ammonia.

    PubMed

    Chen, W; Metsälä, M; Vaittinen, O; Halonen, L

    2014-09-01

    It is known that the oral cavity is a production site for mouth-exhaled NH3. However, the mechanism of NH3 production in the oral cavity has been unclear. Since bacterial urease in the oral cavity has been found to produce ammonia from oral fluid urea, we hypothesize that oral fluid urea is the origin of mouth-exhaled NH3. Our results show that under certain conditions a strong correlation exists between oral fluid urea and oral fluid ammonia (NH4(+)+NH3) (rs = 0.77, p < 0.001). We also observe a strong correlation between oral fluid NH3 and mouth-exhaled NH3 (rs = 0.81, p < 0.001). We conclude that three main factors affect the mouth-exhaled NH3 concentration: urea concentration, urease activity and oral fluid pH. Bacterial urease catalyses the hydrolysis of oral fluid urea to ammonia (NH4(+)+NH3). Oral fluid ammonia (NH4(+)+NH3) and pH determine the concentration of oral fluid NH3, which evaporates from oral fluid into gas phase and turns to mouth-exhaled NH3.

  8. Radiation chemistry in ammonia-water ices

    SciTech Connect

    Loeffler, M. J.; Raut, U.; Baragiola, R. A.

    2010-02-07

    We studied the effects of 100 keV proton irradiation on films of ammonia-water mixtures between 20 and 120 K. Irradiation destroys ammonia, leading to the formation and trapping of H{sub 2}, N{sub 2}, NO, and N{sub 2}O, the formation of cavities containing radiolytic gases, and ejection of molecules by sputtering. Using infrared spectroscopy, we show that at all temperatures the destruction of ammonia is substantial, but at higher temperatures (120 K), it is nearly complete ({approx}97% destroyed) after a fluence of 10{sup 16} ions/cm{sup 2}. Using mass spectroscopy and microbalance gravimetry, we measure the sputtering yield of our sample and the main components of the sputtered flux. We find that the sputtering yield depends on fluence. At low temperatures, the yield is very low initially and increases quadratically with fluence, while at 120 K the yield is constant and higher initially. The increase in the sputtering yield with fluence is explained by the formation and trapping of the ammonia decay products, N{sub 2} and H{sub 2}, which are seen to be ejected from the ice at all temperatures.

  9. AMMONIA EMISSION FACTORS FROM SWINE FINISHING OPERATIONS

    EPA Science Inventory

    The paper presents results from two new studies at swine finishing facilities. (NOTE: Concentrated anaimal feeding operations (CAFOs) are being examined in several regions of the U.S. as major sources of ammonia and particulate matter precursors. EPA's National Risk Management Re...

  10. Effect of ammonia on Swiss albino mice

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Casey, C. J.; Furst, A.

    1977-01-01

    Times to incapacitation and death and LC /50/ values were determined for Swiss albino male mice exposed to different concentrations of ammonia in a 4.2 liter hemispherical chamber. The LC/50/ for a 30 minute exposure was 21,430 ppm.

  11. Atmospheric ammonia emissions from agricultural waste combustion

    NASA Astrophysics Data System (ADS)

    Lee, David S.; Atkins, D. H. F.

    1994-02-01

    Measurements of ammonia and ammonium aerosol were made during straw and stubble burning experiments in the field. Factors were determined for the calculation of emissions of ammonia and ammonium ion, from this source, in the United Kingdom between 1981 and 1992. Emissions of NHx from straw burning were calculated to be equivalent to approximately 20 ktonnes N yr-1 in 1981 and have declined to 3.3 ktonnes N yr-1 in 1991 as a result of changes in agricultural practices in response to impending U.K. legislation. The fraction of total plant nitrogen released as NHx was estimated to be between approximately 40 and 80%. Emissions of ammonia from straw and stubble burning over a 6—8 week period over which this typically occurs were calculated to be 27% of the total U.K. emissions over the equivalent period in 1981 and 7% in 1991. We have identified straw and stubble burning as another source of ammonia currently not accounted for in European and North American emission inventories; these focus almost exclusively on emissions from animal sources.

  12. Effect of tryptone and ammonia on the biogas process in continuously stirred tank reactors treating cattle manure.

    PubMed

    Nielsen, H B; Ahring, B K

    2007-08-01

    Two thermophilic continuously stirred tank reactors, R1 and R2, were subject to pulses of tryptone and ammonia. R1 was operated at an ammonia-N concentration of 3.0 g l(-1) and R2 was operated at an ammonia-N concentration of 1.7 g l(-1). Shock loads of tryptone (10 g l(-1), 10 g l(-1), 15 g l(-1)) had an immediate stimulating effect on methanogenesis for both reactors illustrated by significant peaks in methane production but also led to an organic overloading illustrated by a steep increase in volatile fatty acids (VFA) concentration. Three days after the pulses a second peak in acetate concentration and a decrease in methane production indicated an ammonia-inhibition of the acetoclastic methanogens. During the pulses of tryptone the performance of R1 was slightly more affected than R2. Pulses of ammonia (0.79 g l(-1) as N) resulted in a decrease in methane production of both reactors but no immediate increases in VFA concentrations was observed illustrating that the ammonia inhibition during this experiment was an overall inhibition of the biogas process and not only an inhibition of the methanogens.

  13. Ammonia downstream from HH 80 North

    NASA Technical Reports Server (NTRS)

    Girart, Jose M.; Rodriguez, Luis F.; Anglada, Guillem; Estalella, Robert; Torrelles, Jose, M.; Marti, Josep; Pena, Miriam; Ayala, Sandra; Curiel, Salvador; Noriega-Crespo, Alberto

    1994-01-01

    HH 80-81 are two optically visible Herbig-Haro (HH) objects located about 5 minutes south of their exciting source IRAS 18162-2048. Displaced symmetrically to the north of this luminous IRAS source, a possible HH counterpart was recently detected as a radio continuum source with the very large array (VLA). This radio source, HH 80 North, has been proposed to be a member of the Herbig-Haro class since its centimeter flux density, angular size, spectral index, and morphology are all similar to those of HH 80. However, no object has been detected at optical wavelengths at the position of HH 80 North, possibly because of high extinction, and the confirmation of the radio continuum source as an HH object has not been possible. In the prototypical Herbig-Haro objects HH 1 and 2, ammonia emission has been detected downstream of the flow in both objects. This detection has been intepreted as a result of an enhancement in the ammonia emission produced by the radiation field of the shock associated with the HH object. In this Letter we report the detection of the (1,1) and (2,2) inversion transitions of ammonia downstream HH 80 North. This detection gives strong suppport to the interpretation of HH 80 North as a heavily obscured HH object. In addition, we suggest that ammonia emission may be a tracer of embedded Herbig-Haro objects in other regions of star formation. A 60 micrometer IRAS source could be associated with HH 80 North and with the ammonia condensation. A tentative explanation for the far-infrared emission as arising in dust heated by their optical and UV radiation of the HH object is presented.

  14. On the Ammonia Absorption on Saturn

    NASA Astrophysics Data System (ADS)

    Tejfel, Victor G.; Karimov, A. M.; Lyssenko, P. G.; Kharitonova, G. A.

    2015-11-01

    The ammonia absorption bands centered at wavelengths of 645 and 787 nm in the visible spectrum of Saturn are very weak and overlapped with more strong absorption bands of methane. Therefore, the allocation of these bands is extremely difficult. In fact, the NH3 band 787 nm is completely masked by methane. The NH3 645 nm absorption band is superimposed on a relatively weak shortwave wing of CH4 band, in which the absorption maximum lies at the wavelength of 667 nm. In 2009, during the equinox on Saturn we have obtained the series of zonal spectrograms by scanning of the planet disk from the southern to the northern polar limb. Besides studies of latitudinal variation of the methane absorption bands we have done an attempt to trace the behavior of the absorption of ammonia in the band 645 nm. Simple selection of the pure NH3 profile of the band was not very reliable. Therefore, after normalizing to the ring spectrum and to the level of the continuous spectrum for entire band ranging from 630 to 680 nm in the equivalent widths were calculated for shortwave part of this band (630-652 nm), where the ammonia absorption is present, and a portion of the band CH4 652-680 nm. In any method of eliminating the weak part of the methane uptake in the short wing show an increased ammonia absorption in the northern hemisphere compared to the south. This same feature is observed also in the behavior of weak absorption bands of methane in contrast to the more powerful, such as CH4 725 and 787 nm. This is due to the conditions of absorption bands formation in the clouds at multiple scattering. Weak absorption bands of methane and ammonia are formed on the large effective optical depths and their behavior reflects the differences in the degree of uniformity of the aerosol component of the atmosphere of Saturn.

  15. AMMONIA CONCENTRATION IN SALTSTONE HEADSPACE SUMMARY REPORT

    SciTech Connect

    Zamecnik, J; Alex Cozzi, A

    2008-09-26

    The Saltstone Facility Documented Safety Analysis (DSA) is under revision to accommodate changes in the Composite Lower Flammability Limit (CLFL) from the introduction of Isopar into Tank 50. Saltstone samples were prepared with an 'MCU' type salt solution spiked with ammonia. The ammonia released from the saltstone was captured and analyzed. The ammonia concentration found in the headspace of samples maintained at 95 C and 1 atm was, to 95% confidence, less than or equal to 3.9 mg/L. Tank 50 is fed by several influent streams. The salt solution from Tank 50 is pumped to the salt feed tank (SFT) in the Saltstone Production Facility (SPF). The premix materials cement, slag and fly ash are blended together prior to transfer to the grout mixer. The premix is fed to the grout mixer in the SPF and the salt solution is incorporated into the premix in the grout mixer, yielding saltstone slurry. The saltstone slurry drops into a hopper and then is pumped to the vault. The Saltstone Facility Documented Safety Analysis (DSA) is under revision to accommodate changes in the Composite Lower Flammability Limit (CLFL) from the introduction of Isopar{reg_sign} L into Tank 50. Waste Solidification-Engineering requested that the Savannah River National Laboratory (SRNL) perform testing to characterize the release of ammonia in curing saltstone at 95 C. The test temperature represents the maximum allowable temperature in the Saltstone Disposal Facility (SDF). Ammonia may be present in the salt solution and premix materials, or may be produced by chemical reactions when the premix and salt solution are combined. A final report (SRNS-STI-2008-00120, Rev. 0) will be issued that will cover in more depth the information presented in this report.

  16. Ammonia and ammonium hydroxide sensors for ammonia/water absorption machines: Literature review and data compilation

    NASA Astrophysics Data System (ADS)

    Anheier, N. C., Jr.; McDonald, C. E.; Cuta, J. M.; Cuta, F. M.; Olsen, K. B.

    1995-05-01

    This report describes an evaluation of various sensing techniques for determining the ammonia concentration in the working fluid of ammonia/water absorption cycle systems. The purpose was to determine if any existing sensor technology or instrumentation could provide an accurate, reliable, and cost-effective continuous measure of ammonia concentration in water. The resulting information will be used for design optimization and cycle control in an ammonia-absorption heat pump. Pacific Northwest Laboratory (PNL) researchers evaluated each sensing technology against a set of general requirements characterizing the potential operating conditions within the absorption cycle. The criteria included the physical constraints for in situ operation, sensor characteristics, and sensor application. PNL performed an extensive literature search, which uncovered several promising sensing technologies that might be applicable to this problem. Sixty-two references were investigated, and 33 commercial vendors were identified as having ammonia sensors. The technologies for ammonia sensing are acoustic wave, refractive index, electrode, thermal, ion-selective field-effect transistor (ISFET), electrical conductivity, pH/colormetric, and optical absorption. Based on information acquired in the literature search, PNL recommends that follow-on activities focus on ISFET devices and a fiber optic evanescent sensor with a colormetric indicator. The ISFET and fiber optic evanescent sensor are inherently microminiature and capable of in situ measurements. Further, both techniques have been demonstrated selective to the ammonium ion (NH4(+)). The primary issue remaining is how to make the sensors sufficiently corrosion-resistant to be useful in practice.

  17. Ammonia and ammonium hydroxide sensors for ammonia/water absorption machines: Literature review and data compilation

    SciTech Connect

    Anheier, N.C. Jr.; McDonald, C.E.; Cuta, J.M.; Cuta, F.M.; Olsen, K.B.

    1995-05-01

    This report describes an evaluation of various sensing techniques for determining the ammonia concentration in the working fluid of ammonia/water absorption cycle systems. The purpose of this work was to determine if any existing sensor technology or instrumentation could provide an accurate, reliable, and cost-effective continuous measure of ammonia concentration in water. The resulting information will be used for design optimization and cycle control in an ammonia-absorption heat pump. PNL researchers evaluated each sensing technology against a set of general requirements characterizing the potential operating conditions within the absorption cycle. The criteria included the physical constraints for in situ operation, sensor characteristics, and sensor application. PNL performed an extensive literature search, which uncovered several promising sensing technologies that might be applicable to this problem. Sixty-two references were investigated, and 33 commercial vendors were identified as having ammonia sensors. The technologies for ammonia sensing are acoustic wave, refractive index, electrode, thermal, ion-selective field-effect transistor (ISFET), electrical conductivity, pH/colormetric, and optical absorption. Based on information acquired in the literature search, PNL recommends that follow-on activities focus on ISFET devices and a fiber optic evanescent sensor with a colormetric indicator. The ISFET and fiber optic evanescent sensor are inherently microminiature and capable of in situ measurements. Further, both techniques have been demonstrated selective to the ammonium ion (NH{sub 4}{sup +}). The primary issue remaining is how to make the sensors sufficiently corrosion-resistant to be useful in practice.

  18. High Brain Ammonia Tolerance and Down-Regulation of Na+:K+:2Cl- Cotransporter 1b mRNA and Protein Expression in the Brain of the Swamp Eel, Monopterus albus, Exposed to Environmental Ammonia or Terrestrial Conditions

    PubMed Central

    Ip, Yuen K.; Hou, Zhisheng; Chen, Xiu L.; Ong, Jasmine L. Y.; Chng, You R.; Ching, Biyun; Hiong, Kum C.; Chew, Shit F.

    2013-01-01

    Na+:K+:2Cl- cotransporter 1 (NKCC1) has been implicated in mediating ischemia-, trauma- or ammonia-induced astrocyte swelling/brain edema in mammals. This study aimed to determine the effects of ammonia or terrestrial exposure on ammonia concentrations in the plasma and brain, and the mRNA expression and protein abundance of nkcc/Nkcc in the brain, of the swamp eel Monopterusalbus. Ammonia exposure led to a greater increase in the ammonia concentration in the brain of M. albus than terrestrial exposure. The brain ammonia concentration of M. albus reached 4.5 µmol g-1 and 2.7 µmol g-1 after 6 days of exposure to 50 mmol l-1 NH4Cl and terrestrial conditions, respectively. The full cDNA coding sequence of nkcc1b from M. albus brain comprised 3276 bp and coded for 1092 amino acids with an estimated molecular mass of 119.6 kDa. A molecular characterization indicated that it could be activated through phosphorylation and/or glycosylation by osmotic and/or oxidative stresses. Ammonia exposure for 1 day or 6 days led to significant decreases in the nkcc1b mRNA expression and Nkcc1b protein abundance in the brain of M. albus. In comparison, a significant decrease in nkcc1b mRNA expression was observed in the brain of M. albus only after 6 days of terrestrial exposure, but both 1 day and 6 days of terrestrial exposure resulted in significant decreases in the protein abundance of Nkcc1b. These results are novel because it has been established in mammals that ammonia up-regulates NKCC1 expression in astrocytes and NKCC1 plays an important role in ammonia-induced astrocyte swelling and brain edema. By contrast, our results indicate for the first time that M. albus is able to down-regulate the mRNA and protein expression of nkcc1b/Nkcc1b in the brain when confronted with ammonia toxicity, which could be one of the contributing factors to its extraordinarily high brain ammonia tolerance. PMID:24069137

  19. Optimization of the tungsten oxide technique for measurement of atmospheric ammonia

    NASA Technical Reports Server (NTRS)

    Brown, Kenneth G.

    1987-01-01

    Hollow tubes coated with tungstic acid have been shown to be of value in the determination of ammonia and nitric acid in ambient air. Practical application of this technique was demonstrated utilizing an automated sampling system for in-flight collection and analysis of atmospheric samples. Due to time constraints these previous measurements were performed on tubes that had not been well characterized in the laboratory. As a result the experimental precision could not be accurately estimated. Since the technique was being compared to other techniques for measuring these compounds, it became necessary to perform laboratory tests which would establish the reliability of the technique. This report is a summary of these laboratory experiments as they are applied to the determination of ambient ammonia concentration.

  20. Metal-decorated graphene oxide for ammonia adsorption

    NASA Astrophysics Data System (ADS)

    Li, Yunguo; Pathak, Biswarup; Nisar, Jawad; Qian, Zhao; Ahuja, Rajeev

    2013-07-01

    Based on the first-principles density functional theory, we have studied the stability, electronic structure and ammonia storage capacity of metal-decorated graphene oxide (GO). Metal atoms (Mg and Li) are bonded strongly to the epoxy oxygen atoms on the surface of the GO sheet, which can act as high-surface-area adsorbent for the ammonia uptake and release. Each metal atom can bind several ammonia molecules around itself with a reasonable binding energy. We find metal-decorated GO can store up to tens of moles of ammonia per kilogram, which is far better than the recently reported excellent ammonia adsorption by GO.

  1. Establishing relative sensitivities of various toxicity testing organisms to ammonia

    SciTech Connect

    Karle, L.M.; Mayhew, H.L.; Barrows, M.E.; Karls, R.K.

    1994-12-31

    The toxicity of ammonia to various organisms was examined to develop a baseline for mortality in several commonly used testing species. This baseline data will assist in choosing the proper test species and in interpreting results as they pertain to ammonia. Responses for two juvenile fish species, three marine amphipods, and two species of mysid shrimp were compared for their sensitivity to levels of ammonia. All mortality caused by ammonia in the bottom-dwelling Citharichthys stigmaeus occurred within 24 h of exposure, whereas mortality in the silverside, Menidia beryllina, occurred over the entire 96-h test duration. Responses to ammonia varied among the amphipods Rhepoxynius abronius, Ampelisca abdita, and Eohaustorius estuarius. R. abronius and A. abdita showed similar sensitivity to ammonia at lower concentrations; A. abdita appeared more sensitive than R. abronius at levels above 40 mg/L. Concentrations of ammonia required to produce significant mortality in the amphipod E. estuarius were far higher than the other species examined (> 100 mg/L NH{sub 3}). A comparison of ammonia toxicity with two commonly used invertebrates, Holmesimysis sculpts and Mysidopsis bahia, suggest that these two species of mysid have similar sensitivities to ammonia. Further studies with ammonia that examine sensitivity of different organisms should be conducted to assist regulatory and environmental agencies in determining appropriate test species and in interpreting toxicological results as they may be affected by levels of ammonia.

  2. Pretreatment of Biomass by Aqueous Ammonia for Bioethanol Production

    NASA Astrophysics Data System (ADS)

    Kim, Tae Hyun; Gupta, Rajesh; Lee, Y. Y.

    The methods of pretreatment of lignocellulosic biomass using aqueous ammonia are described. The main effect of ammonia treatment of biomass is delignification without significantly affecting the carbohydrate contents. It is a very effective pretreatment method especially for substrates that have low lignin contents such as agricultural residues and herbaceous feedstock. The ammonia-based pretreatment is well suited for simultaneous saccharification and co-fermentation (SSCF) because the treated biomass retains cellulose as well as hemicellulose. It has been demonstrated that overall ethanol yield above 75% of the theoretical maximum on the basis of total carbohydrate is achievable from corn stover pretreated with aqueous ammonia by way of SSCF. There are two different types of pretreatment methods based on aqueous ammonia: (1) high severity, low contact time process (ammonia recycle percolation; ARP), (2) low severity, high treatment time process (soaking in aqueous ammonia; SAA). Both of these methods are described and discussed for their features and effectiveness.

  3. Spin-state chemistry of deuterated ammonia

    NASA Astrophysics Data System (ADS)

    Sipilä, O.; Harju, J.; Caselli, P.; Schlemmer, S.

    2015-09-01

    Aims: We aim to develop a chemical model that contains a consistent description of spin-state chemistry in reactions involving chemical species with multiple deuterons. We apply the model to the specific case of deuterated ammonia, to derive values for the various spin-state ratios. Methods: We applied symmetry rules in the context of the complete scrambling assumption to calculate branching ratio tables for reactions between chemical species that include multiple protons and/or deuterons. New reaction sets for both gas-phase and grain-surface chemistry were generated using an automated routine that forms all possible spin-state variants of any given reaction with up to six H/D atoms, using the predetermined branching ratios. Both a single-point and a modified Bonnor-Ebert model were considered to study the density and temperature dependence of ammonia and its isotopologs, and the associated spin-state ratios. Results: We find that the spin-state ratios of the ammonia isotopologs are, at late times, very different from their statistical values. The ratios are rather insensitive to variations in the density, but present strong temperature dependence. We derive high peak values (~0.1) for the deuterium fraction in ammonia, in agreement with previous (gas-phase) models. The deuterium fractionation is strongest at high density, corresponding to a high degree of depletion, and also presents temperature dependence. We find that in the temperature range 5 K to 20 K, the deuterium fractionation peaks at ~15 K, while most of the ortho/para (and meta/para for ND3) ratios present a minimum at 10 K (ortho/para NH2D has instead a maximum at this temperature). Conclusions: Owing to the density and temperature dependence found in the abundances and spin-state ratios of ammonia and its isotopologs, it is evident that observations of ammonia and its deuterated forms can provide important constraints on the physical structure of molecular clouds. Appendix A is available in

  4. Enhanced anaerobic digestion of piggery wastewater by ammonia stripping: effects of alkali types.

    PubMed

    Zhang, Lei; Jahng, Deokjin

    2010-10-15

    Air stripping at alkaline pH was carried out to remove ammonia from the piggery wastewater, and its effects on subsequent anaerobic digestion were investigated in semi-continuous experiments. In ammonia stripping process, three alkalis (NaOH, KOH and CaO) were used for pH adjustment. When using NaOH and KOH, the methane production rate increased more than two folds as compared to the control (no ammonia stripped), but cation toxicity exerted by sodium and potassium ions was observed. When using lime, on the contrary, it was found that volumetric methane production rates (1040-1130 mL CH(4)/L day) and yields (262.3-258.9 mL CH(4)/g of COD(added)) were significantly higher than others. In addition, the organic removal efficiencies (54.2-59.5% of volatile solid, 59.6-64.0% of total COD, 72.1-81.9% of soluble COD and 89.3-98.9% of volatile fatty acid) were also high. Batch toxicity test results confirmed that cations of Na(+), K(+) were strong methanogenic inhibitors as compared to Ca(2+). From these observations, it was concluded that ammonia stripping at alkaline pH is important for anaerobic digestion of piggery wastewater and the alkali types should be chosen cautiously to avoid cation toxicity.

  5. Species, Abundance and Function of Ammonia-oxidizing Archaea in Inland Waters across China

    NASA Astrophysics Data System (ADS)

    Zhou, Leiliu; Wang, Shanyun; Zou, Yuxuan; Xia, Chao; Zhu, Guibing

    2015-11-01

    Ammonia oxidation is the first step in nitrification and was thought to be performed solely by specialized bacteria. The discovery of ammonia-oxidizing archaea (AOA) changed this view. We examined the large scale and spatio-temporal occurrence, abundance and role of AOA throughout Chinese inland waters (n = 28). Molecular survey showed that AOA was ubiquitous in inland waters. The existence of AOA in extreme acidic, alkaline, hot, cold, eutrophic and oligotrophic environments expanded the tolerance limits of AOA, especially their known temperature tolerance to -25 °C, and substrate load to 42.04 mM. There were spatio-temporal divergences of AOA community structure in inland waters, and the diversity of AOA in inland water ecosystems was high with 34 observed species-level operational taxonomic units (OTUs; based on a 15% cutoff) distributed widely in group I.1b, I.1a, and I.1a-associated. The abundance of AOA was quite high (8.5 × 104 to 8.5 × 109 copies g-1), and AOA outnumbered ammonia-oxidizing bacteria (AOB) in the inland waters where little human activities were involved. On the whole AOB predominate the ammonia oxidation rate over AOA in inland water ecosystems, and AOA play an indispensable role in global nitrogen cycle considering that AOA occupy a broader habitat range than AOB, especially in extreme environments.

  6. The protective effects of taurine on acute ammonia toxicity in grass carp Ctenopharynodon idellus.

    PubMed

    Xing, Xiaodan; Li, Ming; Yuan, Lixia; Song, Meize; Ren, Qianyan; Shi, Ge; Meng, Fanxing; Wang, Rixin

    2016-09-01

    The four experimental groups were carried out to test the response of grass carp Ctenopharyngodon idella to ammonia toxicity and taurine: group 1 was injected with NaCl, group 2 was injected with ammonium acetate, group 3 was injected with ammonium acetate and taurine, and group 4 was injected taurine. Fish in group 2 had the highest ammonia content in the liver and brain, and alanine, arginine, glutamine, glutamate and glycine contents in liver. Brain alanine and glutamate of fish in group 2 were significantly higher than those of fish in group 1. Malondialdehyde content of fish in group 2 was the highest, but superoxide dismutase and glutathione activities were the lowest. Although fish in group 2 had the lowest red cell count and hemoglobin, the highest alkaline phosphatase, complement C3, C4 and total immunoglobulin contents appeared in this group. In addition, superoxide dismutase and glutathione activities, red cell count and hemoglobin of fish in group 3 were significantly higher than those of fish in group 2, but malondialdehyde content is the opposite. This study indicates that ammonia exerts its toxic effects by interfering with amino acid transport, inducing reactive oxygen species generation and malondialdehyde accumulation, leading to blood deterioration and over-activation of immune response. The exogenous taurine could mitigate the adverse effect of high ammonia level on fish physiological disorder. PMID:27514785

  7. Species, Abundance and Function of Ammonia-oxidizing Archaea in Inland Waters across China.

    PubMed

    Zhou, Leiliu; Wang, Shanyun; Zou, Yuxuan; Xia, Chao; Zhu, Guibing

    2015-01-01

    Ammonia oxidation is the first step in nitrification and was thought to be performed solely by specialized bacteria. The discovery of ammonia-oxidizing archaea (AOA) changed this view. We examined the large scale and spatio-temporal occurrence, abundance and role of AOA throughout Chinese inland waters (n = 28). Molecular survey showed that AOA was ubiquitous in inland waters. The existence of AOA in extreme acidic, alkaline, hot, cold, eutrophic and oligotrophic environments expanded the tolerance limits of AOA, especially their known temperature tolerance to -25 °C, and substrate load to 42.04 mM. There were spatio-temporal divergences of AOA community structure in inland waters, and the diversity of AOA in inland water ecosystems was high with 34 observed species-level operational taxonomic units (OTUs; based on a 15% cutoff) distributed widely in group I.1b, I.1a, and I.1a-associated. The abundance of AOA was quite high (8.5 × 10(4) to 8.5 × 10(9) copies g(-1)), and AOA outnumbered ammonia-oxidizing bacteria (AOB) in the inland waters where little human activities were involved. On the whole AOB predominate the ammonia oxidation rate over AOA in inland water ecosystems, and AOA play an indispensable role in global nitrogen cycle considering that AOA occupy a broader habitat range than AOB, especially in extreme environments. PMID:26522086

  8. Species, Abundance and Function of Ammonia-oxidizing Archaea in Inland Waters across China.

    PubMed

    Zhou, Leiliu; Wang, Shanyun; Zou, Yuxuan; Xia, Chao; Zhu, Guibing

    2015-01-01

    Ammonia oxidation is the first step in nitrification and was thought to be performed solely by specialized bacteria. The discovery of ammonia-oxidizing archaea (AOA) changed this view. We examined the large scale and spatio-temporal occurrence, abundance and role of AOA throughout Chinese inland waters (n = 28). Molecular survey showed that AOA was ubiquitous in inland waters. The existence of AOA in extreme acidic, alkaline, hot, cold, eutrophic and oligotrophic environments expanded the tolerance limits of AOA, especially their known temperature tolerance to -25 °C, and substrate load to 42.04 mM. There were spatio-temporal divergences of AOA community structure in inland waters, and the diversity of AOA in inland water ecosystems was high with 34 observed species-level operational taxonomic units (OTUs; based on a 15% cutoff) distributed widely in group I.1b, I.1a, and I.1a-associated. The abundance of AOA was quite high (8.5 × 10(4) to 8.5 × 10(9) copies g(-1)), and AOA outnumbered ammonia-oxidizing bacteria (AOB) in the inland waters where little human activities were involved. On the whole AOB predominate the ammonia oxidation rate over AOA in inland water ecosystems, and AOA play an indispensable role in global nitrogen cycle considering that AOA occupy a broader habitat range than AOB, especially in extreme environments.

  9. Species, Abundance and Function of Ammonia-oxidizing Archaea in Inland Waters across China

    PubMed Central

    Zhou, Leiliu; Wang, Shanyun; Zou, Yuxuan; Xia, Chao; Zhu, Guibing

    2015-01-01

    Ammonia oxidation is the first step in nitrification and was thought to be performed solely by specialized bacteria. The discovery of ammonia-oxidizing archaea (AOA) changed this view. We examined the large scale and spatio-temporal occurrence, abundance and role of AOA throughout Chinese inland waters (n = 28). Molecular survey showed that AOA was ubiquitous in inland waters. The existence of AOA in extreme acidic, alkaline, hot, cold, eutrophic and oligotrophic environments expanded the tolerance limits of AOA, especially their known temperature tolerance to −25 °C, and substrate load to 42.04 mM. There were spatio-temporal divergences of AOA community structure in inland waters, and the diversity of AOA in inland water ecosystems was high with 34 observed species-level operational taxonomic units (OTUs; based on a 15% cutoff) distributed widely in group I.1b, I.1a, and I.1a-associated. The abundance of AOA was quite high (8.5 × 104 to 8.5 × 109 copies g−1), and AOA outnumbered ammonia-oxidizing bacteria (AOB) in the inland waters where little human activities were involved. On the whole AOB predominate the ammonia oxidation rate over AOA in inland water ecosystems, and AOA play an indispensable role in global nitrogen cycle considering that AOA occupy a broader habitat range than AOB, especially in extreme environments. PMID:26522086

  10. Ammonia-treated porous carbon derived from ZIF-8 for enhanced CO2 adsorption

    NASA Astrophysics Data System (ADS)

    Ma, Xiancheng; Li, Liqing; Wang, Shaobin; Lu, Mingming; Li, Hailong; Ma, Weiwu; Keener, Tim C.

    2016-04-01

    A porous carbon (ZC) was prepared at 900 °C using zeolitic imidazolate framework-8 (ZIF-8) as a solid template for CO2 adsorption. The ZC was further treated by ammonia functionalization to improve CO2 uptake. The textural and surface characteristics of ZC samples were determined by X-ray diffraction (XRD), N2 adsorption, Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). It was revealed that ammonia treatment at 600 °C considerably enhanced the specific surface area and N-content of ZC. However, the pyrrolic-N group was decreased, yet the pyridinic-N group was increased with an increased temperature. The pyrrolic-N significantly enhanced CO2 adsorption. The ammonia treatment, on the one hand, increases the alkalinity of ZC sample and the base-acid interaction between N-containing functional groups with CO2. On the other hand, the ammonia treatment increased pyrrolic-N group (NH) into carbon surface facilitating the hydrogen-bonding interactions between proton of pyrrolic-N and CO2 molecules.

  11. High yield shock synthesis of ammonia from iron, water and nitrogen available on the early Earth

    NASA Astrophysics Data System (ADS)

    Nakazawa, Hiromoto; Sekine, Toshimori; Kakegawa, Takeshi; Nakazawa, Satoru

    2005-06-01

    Ammonia is a necessary precursor of amino acids in terms of the origin of life on the early Earth. However, the formation of ammonia is problematic in the non-reducing atmosphere that presently believed on the early Earth. The abiotic reduction of nitrogen is, therefore, debated currently in the oceanic and hydrothermal conditions [[J.A. Brandes, N.Z. Boctor, G.D. Cody, B.A. Cooper, R.M. Hazen, H.S. Yoder Jr., Abiotic nitrogen reduction on the early Earth, Nature 395 (1998), 365-367; D.P. Summers, S. Chang, Prebiotic ammonia from reduction of nitrite by iron (II) on the early Earth, Nature 365 (1993), 630-633; M. Dörr, J. Kaessbohrer, R. Grunert, G. Kreisel, W.A. Brand, R.A. Werner, H. Geilmann, C. Apfel, C. Robl, W. Weigand, A possible prebiotic formation of ammonia from dinitrogen on iron sulfide surfaces, Angew. Chem. Int. Ed. 42 ( 2003), 1540-1543 [1-3

  12. Was early Mars warmed by ammonia?

    NASA Technical Reports Server (NTRS)

    Kasting, J. F.; Brown, L. L.; Acord, J. M.; Pollack, J. B.

    1992-01-01

    Runoff channels and valley networks present on ancient, heavily cratered Martian terrain suggests that the climate of Mars was originally warm and wet. One explanation for the formation of these channels is that the surface was warmed by the greenhouse effect of a dense, CO2 atmosphere. However, recent work shows that this theory is not consistent for the early period of the solar system. One way to increase the surface temperature predicted is to assume that other greenhouse gases were present in Mars' atmosphere in addition to CO2 and H2O. This possible gas is ammonia, NH3. If ammonia was present in sufficient quantities, it could have raised the surface temperature to 273 K. An adequate source would have been volcanic outgassing if the NH3 produced was shielded from photolysis by an ultraviolet light absorber.

  13. Optically pumped isotopic ammonia laser system

    DOEpatents

    Buchwald, Melvin I.; Jones, Claude R.; Nelson, Leonard Y.

    1982-01-01

    An optically pumped isotopic ammonia laser system which is capable of producing a plurality of frequencies in the middle infrared spectral region. Two optical pumping mechanisms are disclosed, i.e., pumping on R(J) and lasing on P(J) in response to enhancement of rotational cascade lasing including stimulated Raman effects, and, pumping on R(J) and lasing on P(J+2). The disclosed apparatus for optical pumping include a hole coupled cavity and a grating coupled cavity.

  14. Diverse microbial species survive high ammonia concentrations

    NASA Astrophysics Data System (ADS)

    Kelly, Laura C.; Cockell, Charles S.; Summers, Stephen

    2012-04-01

    Planetary protection regulations are in place to control the contamination of planets and moons with terrestrial micro-organisms in order to avoid jeopardizing future scientific investigations relating to the search for life. One environmental chemical factor of relevance in extraterrestrial environments, specifically in the moons of the outer solar system, is ammonia (NH3). Ammonia is known to be highly toxic to micro-organisms and may disrupt proton motive force, interfere with cellular redox reactions or cause an increase of cell pH. To test the survival potential of terrestrial micro-organisms exposed to such cold, ammonia-rich environments, and to judge whether current planetary protection regulations are sufficient, soil samples were exposed to concentrations of NH3 from 5 to 35% (v/v) at -80°C and room temperature for periods up to 11 months. Following exposure to 35% NH3, diverse spore-forming taxa survived, including representatives of the Firmicutes (Bacillus, Sporosarcina, Viridibacillus, Paenibacillus, Staphylococcus and Brevibacillus) and Actinobacteria (Streptomyces). Non-spore forming organisms also survived, including Proteobacteria (Pseudomonas) and Actinobacteria (Arthrobacter) that are known to have environmentally resistant resting states. Clostridium spp. were isolated from the exposed soil under anaerobic culture. High NH3 was shown to cause a reduction in viability of spores over time, but spore morphology was not visibly altered. In addition to its implications for planetary protection, these data show that a large number of bacteria, potentially including spore-forming pathogens, but also environmentally resistant non-spore-formers, can survive high ammonia concentrations.

  15. Ammonia volatilization from sows on grassland

    NASA Astrophysics Data System (ADS)

    Sommer, S. G.; Søgaard, H. T.; Møller, H. B.; Morsing, S.

    According to regulations, sows with piglets on organic farms must graze on pastures. Volatilization of ammonia (NH 3) from urine patches may represent a significant source of nitrogen (N) loss from these farms. Inputs of N are low on organic farms and losses may reduce crop production. This study examined spatial variations in NH 3 volatilization using a movable dynamic chamber, and the pH and total ammoniacal nitrogen (TAN) content in the topsoil of pastures with grazing sows was measured during five periods between June 1998 and May 1999. Gross NH 3 volatilization from the pastures was also measured with an atmospheric mass balance technique during seven periods from September 1997 until June 1999. The dynamic chamber study showed a high variation in NH 3 volatilization because of the distribution of urine; losses were between 0 and 2.8 g NH 3-N m -2 day -1. Volatilization was highest near the feeding area and the huts, where the sows tended to urinate. Ammonia volatilization rate was linearly related to the product of NH 3 concentration in the boundary layer and wind speed. The NH 3 in the boundary layer was in equilibrium with NH 3 in soil solution. Gross NH 3 volatilization was in the range 0.07-2.1 kg NH 3-N ha -1 day -1 from a pasture with 24 sows ha -1. Ammonia volatilization was related to the amount of feed given to the sows, incident solar radiation and air temperature during measuring periods, and also to temperature, incident solar radiation and rain 1-2 days before measurements. Annual ammonia loss was 4.8 kg NH 3-N sow -1.

  16. Ammonia emissions in Europe, part II: How ammonia emission abatement strategies affect secondary aerosols

    NASA Astrophysics Data System (ADS)

    Backes, Anna M.; Aulinger, Armin; Bieser, Johannes; Matthias, Volker; Quante, Markus

    2016-02-01

    In central Europe, ammonium sulphate and ammonium nitrate make up a large fraction of fine particles which pose a threat to human health. Most studies on air pollution through particulate matter investigate the influence of emission reductions of sulphur- and nitrogen oxides on aerosol concentration. Here, we focus on the influence of ammonia (NH3) emissions. Emission scenarios have been created on the basis of the improved ammonia emission parameterization implemented in the SMOKE for Europe and CMAQ model systems described in part I of this study. This includes emissions based on future European legislation (the National Emission Ceilings) as well as a dynamic evaluation of the influence of different agricultural sectors (e.g. animal husbandry) on particle formation. The study compares the concentrations of NH3, NH4+, NO3 -, sulphur compounds and the total concentration of particles in winter and summer for a political-, technical- and behavioural scenario. It was found that a reduction of ammonia emissions by 50% lead to a 24% reduction of the total PM2.5 concentrations in northwest Europe. The observed reduction was mainly driven by reduced formation of ammonium nitrate. Moreover, emission reductions during winter had a larger impact than during the rest of the year. This leads to the conclusion that a reduction of the ammonia emissions from the agricultural sector related to animal husbandry could be more efficient than the reduction from other sectors due to its larger share in winter ammonia emissions.

  17. Ammonia and nitrite oxidation in the Eastern Tropical North Pacific

    NASA Astrophysics Data System (ADS)

    Peng, Xuefeng; Fuchsman, Clara A.; Jayakumar, Amal; Oleynik, Sergey; Martens-Habbena, Willm; Devol, Allan H.; Ward, Bess B.

    2015-12-01

    Nitrification plays a key role in the marine nitrogen (N) cycle, including in oceanic oxygen minimum zones (OMZs), which are hot spots for denitrification and anaerobic ammonia oxidation (anammox). Recent evidence suggests that nitrification links the source (remineralized organic matter) and sink (denitrification and anammox) of fixed N directly in the steep oxycline in the OMZs. We performed shipboard incubations with 15N tracers to characterize the depth distribution of nitrification in the Eastern Tropical North Pacific (ETNP). Additional experiments were conducted to investigate photoinhibition. Allylthiourea (ATU) was used to distinguish the contribution of archaeal and bacterial ammonia oxidation. The abundance of archaeal and β-proteobacterial ammonia monooxygenase gene subunit A (amoA) was determined by quantitative polymerase chain reaction. The rates of ammonia and nitrite oxidation showed distinct subsurface maxima, with the latter slightly deeper than the former. The ammonia oxidation maximum coincided with the primary nitrite concentration maximum, archaeal amoA gene maximum, and the subsurface nitrous oxide maximum. Negligible rates of ammonia oxidation were found at anoxic depths, where high rates of nitrite oxidation were measured. Archaeal amoA gene abundance was generally 1 to 2 orders of magnitude higher than bacterial amoA gene abundance, and inhibition of ammonia-oxidizing bacteria with 10 μM ATU did not affect ammonia oxidation rates, indicating the dominance of archaea in ammonia oxidation. These results depict highly dynamic activities of ammonia and nitrite oxidation in the oxycline of the ETNP OMZ.

  18. Ammonia causes decreased brain monoamines in fathead minnows (Pimephales promelas)

    USGS Publications Warehouse

    Ronan, Patrick J.; Gaikowski, Mark P.; Hamilton, Steven J.; Buhl, Kevin J.; Summers, Cliff H.

    2007-01-01

    Hyperammonemia, arising from variety of disorders, leads to severe neurological dysfunction. The mechanisms of ammonia toxicity in brain are not completely understood. This study investigated the effects of ammonia on monoaminergic systems in brains of fathead minnows (Pimephales promelas). Fish serve as a good model system to investigate hyperammonemic effects on brain function since no liver manipulations are necessary to increase endogenous ammonia concentrations. Using high performance liquid chromatography with electrochemical detection, monoamines and some associated metabolites were measured from whole brain homogenate. Adult males were exposed for 48 h to six different concentrations of ammonia (0.01–2.36 mg/l unionized) which bracketed the 96-h LC50 for this species. Ammonia concentration-dependent decreases were found for the catecholamines (norepinephrine and dopamine) and the indoleamine serotonin (5-HT). After an initial increase in the 5-HT precursor 5-hydroxytryptophan it too decreased with increasing ammonia concentrations. There were also significant increases in the 5-HIAA/5-HT and DOPAC/DA ratios, often used as measures of turnover. There were no changes in epinephrine (Epi) or monoamine catabolites (DOPAC, 5-HIAA) at any ammonia concentrations tested. Results suggest that ammonia causes decreased synthesis while also causing increased release and degradation. Increased release may underlie behavioral reactions to ammonia exposure in fish. This study adds weight to a growing body of evidence demonstrating that ammonia leads to dysfunctional monoaminergic systems in brain which may underlie neurological symptoms associated with human disorders such as hepatic encephalopathy.

  19. Influence of Nitrate and Ammonia on Photosynthetic Characteristics and Leaf Anatomy of Moricandia arvensis1

    PubMed Central

    Winter, Klaus; Usuda, Hideaki; Tsuzuki, Mikio; Schmitt, Mark; Edwards, Gerald E.; Thomas, Richard J.; Evert, Ray F.

    1982-01-01

    The leaf anatomy and certain photosynthetic properties of nitrate- and ammonia-grown plants of Moricandia arvensis (L.) DC., a species previously reported to be a C3-C4 intermediate, were investigated. Nitrate-grown plants had a high level of malate in the leaves while ammonia-grown plants had low levels of malate. In young leaves of nitrate-grown plants, there was a diurnal fluctuation of malate content, increasing during the day and decreasing during the night. Titratable acidity remained low in leaves of both nitrate- and ammonia-grown plants. In nitrate-grown plants, the activity of phosphoenolpyruvate (PEP) carboxylase was about 2-fold higher than in ammonia-grown plants, the latter having activity typical of C3 species. Also, in nitrate-grown plants, the ratio of activities of ribulose 1,5-bisphosphate (RuBP) carboxylase/PEP carboxylase was lower than in ammonia-grown plants. Nitrate reductase activities were higher in nitrate- than in ammonia-grown plants and the greatest activity was found in younger leaves. With nitrate-grown plants, during a pulse-chase experiment the label in malate, as a percentage of the total labeled products, increased from about 7% after a 10-second pulse with 14CO2 up to 17% during a 5-minute chase with 12CO2. The pattern of 14C labeling in various metabolites suggests the primary carboxylation is through RuBP carboxylase with a secondary carboxylation through PEP carboxylase. In similar experiments, with ammonia-grown plants, the percentage label in malate was only 0% to 4% with no increase in malate labeling during the chase period. The CO2 compensation point was lower in nitrate-grown than ammonia-grown plants. There was no evidence of Kranz-like anatomy in either the nitrate or ammonia-grown plants. Mitochondria of bundle-sheath cells were strikingly positioned along the inner tangential wall. This might allow the chloroplasts of these cells to fix the mitochondrial photorespired CO2 more effectively and contribute to the low

  20. Effects of Glycine, Water, Ammonia, and Ammonium Bicarbonate on the Oligomerization of Methionine

    NASA Astrophysics Data System (ADS)

    Huang, Rui; Furukawa, Yoshihiro; Otake, Tsubasa; Kakegawa, Takeshi

    2016-09-01

    The abiotic oligomerization of amino acids may have created primordial, protein-like biological catalysts on the early Earth. Previous studies have proposed and evaluated the potential of diagenesis for the amino acid oligomerization, simulating the formation of peptides that include glycine, alanine, and valine, separately. However, whether such conditions can promote the formation of peptides composed of multiple amino acids remains unclear. Furthermore, the chemistry of pore water in sediments should affect the oligomerization and degradation of amino acids and oligomers, but these effects have not been studied extensively. In this study, we investigated the effects of water, ammonia, ammonium bicarbonate, pH, and glycine on the oligomerization and degradation of methionine under high pressure (150 MPa) and high temperature conditions (175 °C) for 96 h. Methionine is more difficult to oligomerize than glycine and methionine dimer was formed in the incubation of dry powder of methionine. Methionine oligomers as long as trimers, as well as methionylglycine and glycylmethionine, were formed under every condition with these additional compounds. Among the compounds tested, the oligomerization reaction rate was accelerated by the presence of water and by an increase in pH. Ammonia also increased the oligomerization rate but consumed methionine by side reactions and resulted in the rapid degradation of methionine and its peptides. Similarly, glycine accelerated the oligomerization rate of methionine and the degradation of methionine, producing water, ammonia, and bicarbonate through its decomposition. With Gly, heterogeneous dimers (methionylglycine and glycylmethionine) were formed in greater amounts than with other additional compounds although smaller amount of these heterogeneous dimers were formed with other additional compounds. These results suggest that accelerated reaction rates induced by water and co-existing reactive compounds promote the oligomerization

  1. High protein diet induces pericentral glutamate dehydrogenase and ornithine aminotransferase to provide sufficient glutamate for pericentral detoxification of ammonia in rat liver lobules.

    PubMed

    Boon, L; Geerts, W J; Jonker, A; Lamers, W H; Van Noorden, C J

    1999-06-01

    The liver plays a central role in nitrogen metabolism. Nitrogen enters the liver as free ammonia and as amino acids of which glutamine and alanine are the most important precursors. Detoxification of ammonia to urea involves deamination and transamination. By applying quantitative in situ hybridization, we found that mRNA levels of the enzymes involved are mainly expressed in periportal zones of liver lobules. Free ammonia, that is not converted periportally, is efficiently detoxified in the small rim of hepatocytes around the central veins by glutamine synthetase preventing it from entering the systemic circulation. Detoxification of ammonia by glutamine synthetase may be limited due to a shortage of glutamate when the nitrogen load is high. Adaptations in metabolism that prevent release of toxic ammonia from the liver were studied in rats that were fed diets with different amounts of protein, thereby varying the nitrogen load of the liver. We observed that mRNA levels of periportal deaminating and transaminating enzymes increased with the protein content in the diet. Similarly, mRNA levels of pericentral glutamate dehydrogenase and ornithine aminotransferase, the main producers of glutamate in this zone, and pericentral glutamine synthetase all increased with increasing protein levels in the diet. On the basis of these changes in mRNA levels, we conclude that: (a) glutamate is produced pericentrally in sufficient amounts to allow ammonia detoxification by glutamine synthetase and (b) in addition to the catalytic role of ornithine in the periportally localized ornithine cycle, pericentral ornithine degradation provides glutamate for ammonia detoxification.

  2. Control and pollution prevention options for ammonia emissions

    SciTech Connect

    Phillips, J.

    1995-04-01

    In response to requests for guidance concerning technologies available for the control and prevention of ammonia emissions, the Control Technology Center (CTC) initiated a review of current and potential methods for ammonia emissions control. A review of various industries has identified significant sources of ammonia to be fertilizer production, coke production using the by-product recovery method, fossil fuel combustion, livestock management, and refrigeration using ammonia as a refrigerant. Control methods implemented by these sources include wet scrubbers, condensate strippers, recovery and recycle of exhaust streams, capture systems, and good maintenance practices. The report discusses each industry process identified above, concentrating on the sources of ammonia emissions and the controls and pollution prevention (P2) methods applied. Other industries may have minor ammonia emissions but they are not addressed in this report because neither control technologies nor P2 are applied.

  3. Ambient ammonia measurements using laser photo-acoustic spectroscopy

    NASA Technical Reports Server (NTRS)

    Aldridge, M. D., III; Copeland, G. E.; Harward, C. N.

    1981-01-01

    Ammonia concentrations reached minimal levels (approximately 0.1 ppb) in early winter, followed by a sudden later winter increase. A direct relationship between ambient ammonia levels and air temperature was inferred from the data (linear correlation coefficient r=0.53). Ammonia concentrations were determined to be directly related to the absolute humidity of the air (r=0.72); a weaker relationship between ammonia concentrations and relative humidity was discovered (r=0.37). The data also indicated that ammonia levels were generally higher within continental air masses than those of maritime origin. Soil parameters such as pH and moisture content were found to have a major bearing on the release of gaseous ammonia from soils in the region.

  4. Ammonia removal in constructed wetlands receiving oil sands wastewater

    SciTech Connect

    Bishay, F.S.; Bayley, S.E.; Nix, P.G.

    1995-12-31

    Constructed wetlands are a component of the mine decommissioning and reclamation plan for Suncor Inc., Oil Sands Group, a large oil sands mining and extraction operation in northeastern Alberta, A field, pilot-scale wetlands facility was built in 1991. Over a three year period (1992--1994) the feasibility of constructed wetlands as treatment systems for various oil sands wastewater streams was assessed. Ammonia and hydrocarbons are the primary contaminants. Ammonia removal rates were estimated by measuring inputs and outputs of ammonia, changes in storage, and removal processes. These removal rates were comparable to rates in other studies indicating that the presence of hydrocarbons was not limiting ammonia removal. Nitrogen in sediments and vegetation was elevated; however, removal to sediments or vegetation did not contribute significantly to overall ammonia removal. Volatilization and denitrification were measured in situ. Although neither of these measured processes accounted for all of the ammonia removal, nitrification/denitrification was thought to be the primary removal mechanism.

  5. Ethanol, acetone and ammonia gas room temperature operated sensor

    NASA Astrophysics Data System (ADS)

    Singh, Iqbal; Bedi, R. K.

    2013-06-01

    CuO nanocrystalline thick films were fabricated from powder synthesized by a sol-gel auto combustion route at different pH value of the precursor solution. The gas sensing response of thick film samples towards ethanol, acetone and ammonia gases has been tested and response has been found to be higher for ammonia gas. The sensor recovers its original state after ammonia exposure.

  6. Electron ionization study of ammonia micro-clusters

    PubMed

    Pelc; Michalak

    2000-01-01

    An electron impact ion source on a double focusing sector field mass spectrometer was used to investigate ammonia micro-clusters produced by the adiabatic free jet expansion of ammonia gas. The appearance energies for [NH(3)](n)(+), n ammonia clusters production is proposed. Copyright 2000 John Wiley & Sons, Ltd.

  7. L-Ornithine phenylacetate reduces ammonia in pigs with acute liver failure through phenylacetylglycine formation: a novel ammonia-lowering pathway.

    PubMed

    Kristiansen, Rune Gangsøy; Rose, Christopher F; Fuskevåg, Ole-Martin; Mæhre, Hanne; Revhaug, Arthur; Jalan, Rajiv; Ytrebø, Lars Marius

    2014-11-15

    Glycine is an important ammoniagenic amino acid, which is increased in acute liver failure (ALF). We have previously shown that L-ornithine phenylacetate (OP) attenuates ammonia rise and intracranial pressure in pigs suffering from ALF but failed to demonstrate a stoichiometric relationship between change in plasma ammonia levels and excretion of phenylacetylglutamine in urine. The aim was to investigate the impact of OP treatment on the phenylacetylglycine pathway as an alternative and additional ammonia-lowering pathway. A well-validated and -characterized large porcine model of ALF (portacaval anastomosis, followed by hepatic artery ligation), which recapitulates the cardinal features of human ALF, was used. Twenty-four female pigs were randomized into three groups: (1) sham operated + vehicle, (2) ALF + vehicle, and (3) ALF + OP. There was a significant increase in arterial glycine concentration in ALF (P < 0.001 compared with sham), with a three-fold increase in glycine release into the systemic circulation from the kidney compared with the sham group. This increase was attenuated in both the blood and brain of the OP-treated animals (P < 0.001 and P < 0.05, respectively), and the attenuation was associated with renal removal of glycine through excretion of the conjugation product phenylacetylglycine in urine (ALF + vehicle: 1,060 ± 106 μmol/l; ALF + OP: 27,625 ± 2,670 μmol/l; P < 0.003). Data from this study provide solid evidence for the existence of a novel, additional pathway for ammonia removal in ALF, involving glycine production and removal, which is targeted by OP.

  8. Prebiotic ammonia from reduction of nitrite by iron (II) on the early Earth.

    PubMed

    Summers, D P; Chang, S

    1993-10-14

    Theories for the origin of life require the availability of reduced (or 'fixed') nitrogen-containing compounds, in particular ammonia. In reducing atmospheres, such compounds are readily formed by electrical discharges, but geochemical evidence suggests that the early Earth had a non-reducing atmosphere, in which discharges would have instead produced NO. This would have been converted into nitric and nitrous acids and delivered to the early oceans as acid rain. It is known, however, that Fe(II) was present in the early oceans at much higher concentrations than are found today, and thus the oxidation of Fe(II) to Fe(III) provides a possible means for reducing nitrites and nitrates to ammonia. Here we explore this possibility in a series of experiments which mimic a broad range of prebiotic seawater conditions (the actual conditions on the early Earth remain poorly constrained). We find that the reduction by Fe(II) of nitrites and nitrates to ammonia could have been a significant source of reduced nitrogen on the early Earth, provided that the ocean pH exceeded 7.3 and is favoured for temperatures greater than about 25 degrees C.

  9. [Optimization of liquid ammonia treatment for enzymatic hydrolysis of Saccharum arundinaceum to fermentable sugars].

    PubMed

    Liu, Jianjun; Peng, Hehuan; Zhao, Xiangjun; Cheng, Cheng; Chen, Feng; Shao, Qianjun

    2013-03-01

    China has abundant available marginal land that can be used for cultivation of lignocellulosic energy plants. Saccharum arundinaceum Retz. is a potential energy crop with both high biomass yield and low soil fertility requirements. It can be planted widely as cellulosic ethanol feedstock in southern China. In the present work Saccharum arundinaceum was pretreated by liquid ammonia treatment (LAT) to overcome biomass recalcitrance, followed by enzymatic hydrolysis. The monosaccharide contents (glucose, xylose, and arabinose) of the enzymatic hydrolysate were determined by high performance liquid chromatography. Experimental results show that the optimal LAT pretreatment conditions were 130 0C, 2:1 (W/W) ammonia to biomass ratio, 80% moisture content (dry weight basis) and 5 min residence time. Approximately 69.34% glucan and 82.60% xylan were converted after 72 h enzymatic hydrolysis at 1% glucan loading using 15 FPU/(g of glucan) of cellulase. The yields of glucose and xylose were 573% and 1 056% higher than those of the untreated biomass, and the LAT-pretreated substrates obtained an 8-fold higher of total monosaccharide yield than untreated substrates. LAT pretreatment was an effective to increase the enzymatic digestibility of Saccharum arundinaceum compared to acid impregnated steam explosion and similar to that of acid treatment and ammonia fiber expansion treatment.

  10. Ammonia, a selective agent for methane production by syntrophic acetate oxidation at mesophilic temperature.

    PubMed

    Schnürer, A; Nordberg, A

    2008-01-01

    In biogas processes, methane production from acetate proceeds by either aceticlastic methanogenesis or through syntrophic acetate oxidation (SAO). In the present study, the pathway for methane production from acetate was analysed; i) during a gradual increase of the ammonia concentration (final concentration 7 g NH(4)(+) -N/L) in a semi-continuous lab-scale anaerobic digester (4.3 L), operating at mesophilic temperature (37 degrees C) or ii) in diluted enrichment cultures (100 ml) experiencing a gradual increase in ammonia, sodium, potassium and propionic acid. The pathway for methane formation was determined by calculating the (14)CO(2)/(14)CH(4) ratio after incubating samples with (14)C-2-acetate. In the anaerobic digester, as well as in the enrichment cultures, the (14)CO(2)/(14)CH4 ratio clearly increased with increasing ammonium-nitrogen concentration, i.e. as the ammonia concentration increased, a shift from the aceticlastic mechanism to the syntrophic pathway occurred. The shift was very distinct and occurred as the NH(4)(+) -N concentration rose above 3 g/l. No shift in pathway was seen during increasing concentrations of sodium, potassium or propionic acid. The shift to SAO in the biogas digester resulted in a twofold decrease in the specific gas and methane yield.

  11. Process model for ammonia volatilization from anaerobic swine lagoons incorporating varying wind speeds and biogas bubbling

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ammonia volatilization from treatment lagoons varies widely with the total ammonia concentration, pH, temperature, suspended solids, atmospheric ammonia concentration above the water surface, and wind speed. Ammonia emissions were estimated with a process-based mechanistic model integrating ammonia ...

  12. Biodegradation of cyanuric acid.

    PubMed

    Saldick, J

    1974-12-01

    Cyanuric acid biodegrades readily under a wide variety of natural conditions, and particularly well in systems of either low or zero dissolved-oxygen level, such as anaerobic activated sludge and sewage, soils, muds, and muddy streams and river waters, as well as ordinary aerated activated sludge systems with typically low (1 to 3 ppm) dissolved-oxygen levels. Degradation also proceeds in 3.5% sodium chloride solution. Consequently, there are degradation pathways widely available for breaking down cyanuric acid discharged in domestic effluents. The overall degradation reaction is merely a hydrolysis; CO(2) and ammonia are the initial hydrolytic breakdown products. Since no net oxidation occurs during this breakdown, biodegradation of cyanuric acid exerts no primary biological oxygen demand. However, eventual nitrification of the ammonia released will exert its usual biological oxygen demand.

  13. Biodegradation of Cyanuric Acid

    PubMed Central

    Saldick, Jerome

    1974-01-01

    Cyanuric acid biodegrades readily under a wide variety of natural conditions, and particularly well in systems of either low or zero dissolved-oxygen level, such as anaerobic activated sludge and sewage, soils, muds, and muddy streams and river waters, as well as ordinary aerated activated sludge systems with typically low (1 to 3 ppm) dissolved-oxygen levels. Degradation also proceeds in 3.5% sodium chloride solution. Consequently, there are degradation pathways widely available for breaking down cyanuric acid discharged in domestic effluents. The overall degradation reaction is merely a hydrolysis; CO2 and ammonia are the initial hydrolytic breakdown products. Since no net oxidation occurs during this breakdown, biodegradation of cyanuric acid exerts no primary biological oxygen demand. However, eventual nitrification of the ammonia released will exert its usual biological oxygen demand. PMID:4451360

  14. Microbial communities in liquid and fiber fractions of food waste digestates are differentially resistant to inhibition by ammonia.

    PubMed

    Peng, Wei; Lü, Fan; Shao, Liming; He, Pinjing

    2015-04-01

    The effect of different concentrations of ammonia (1.0-7.0 g/L) during mesophilic anaerobic digestion with fiber or liquid digestate as inoculum was examined. Evolution of microbial community within fiber and liquid digestates was quantitatively assessed by the intact lipid analysis methods and qualitatively by DNA fingerprint methods in order to determine their resistance to ammonia inhibition. The results showed that an increased level of total ammonia nitrogen prolonged the lag phase of fiber digestates while reduced the metabolic rate of liquid digestates. Fiber digestates had 19.6-50.9-fold higher concentrations of phospholipid fatty acids (PLFA) compared to liquid digestates, whereas concentrations of phospholipid ether lipids (PLEL) in the fiber digestates were only 2.91-17.6-fold higher compared to liquid digestates. Although the cell concentration in liquid fraction was far lower than that in the fiber one, the ammonia-resistant ability and the methanization efficiency of the liquid digestate was superior to the fiber digestate. The bacterial profiles were affected more by the type of digestate inoculum compared to the concentration of ammonia. Principal component analysis indicated that the lipids technique was superior to the DNA technique for bacterial quantification but detected less archaeal diversity. PMID:25661818

  15. Genomic Characterization of Phenylalanine Ammonia Lyase Gene in Buckwheat.

    PubMed

    Thiyagarajan, Karthikeyan; Vitali, Fabio; Tolaini, Valentina; Galeffi, Patrizia; Cantale, Cristina; Vikram, Prashant; Singh, Sukhwinder; De Rossi, Patrizia; Nobili, Chiara; Procacci, Silvia; Del Fiore, Antonella; Antonini, Alessandro; Presenti, Ombretta; Brunori, Andrea

    2016-01-01

    Phenylalanine Ammonia Lyase (PAL) gene which plays a key role in bio-synthesis of medicinally important compounds, Rutin/quercetin was sequence characterized for its efficient genomics application. These compounds possessing anti-diabetic and anti-cancer properties and are predominantly produced by Fagopyrum spp. In the present study, PAL gene was sequenced from three Fagopyrum spp. (F. tataricum, F. esculentum and F. dibotrys) and showed the presence of three SNPs and four insertion/deletions at intra and inter specific level. Among them, the potential SNP (position 949th bp G>C) with Parsimony Informative Site was selected and successfully utilised to individuate the zygosity/allelic variation of 16 F. tataricum varieties. Insertion mutations were identified in coding region, which resulted the change of a stretch of 39 amino acids on the putative protein. Our Study revealed that autogamous species (F. tataricum) has lower frequency of observed SNPs as compared to allogamous species (F. dibotrys and F. esculentum). The identified SNPs in F. tataricum didn't result to amino acid change, while in other two species it caused both conservative and non-conservative variations. Consistent pattern of SNPs across the species revealed their phylogenetic importance. We found two groups of F. tataricum and one of them was closely related with F. dibotrys. Sequence characterization information of PAL gene reported in present investigation can be utilized in genetic improvement of buckwheat in reference to its medicinal value. PMID:26990297

  16. Genomic Characterization of Phenylalanine Ammonia Lyase Gene in Buckwheat

    PubMed Central

    Thiyagarajan, Karthikeyan; Vitali, Fabio; Tolaini, Valentina; Galeffi, Patrizia; Cantale, Cristina; Vikram, Prashant; Singh, Sukhwinder; De Rossi, Patrizia; Nobili, Chiara; Procacci, Silvia; Del Fiore, Antonella; Antonini, Alessandro; Presenti, Ombretta; Brunori, Andrea

    2016-01-01

    Phenylalanine Ammonia Lyase (PAL) gene which plays a key role in bio-synthesis of medicinally important compounds, Rutin/quercetin was sequence characterized for its efficient genomics application. These compounds possessing anti-diabetic and anti-cancer properties and are predominantly produced by Fagopyrum spp. In the present study, PAL gene was sequenced from three Fagopyrum spp. (F. tataricum, F. esculentum and F. dibotrys) and showed the presence of three SNPs and four insertion/deletions at intra and inter specific level. Among them, the potential SNP (position 949th bp G>C) with Parsimony Informative Site was selected and successfully utilised to individuate the zygosity/allelic variation of 16 F. tataricum varieties. Insertion mutations were identified in coding region, which resulted the change of a stretch of 39 amino acids on the putative protein. Our Study revealed that autogamous species (F. tataricum) has lower frequency of observed SNPs as compared to allogamous species (F. dibotrys and F. esculentum). The identified SNPs in F. tataricum didn’t result to amino acid change, while in other two species it caused both conservative and non-conservative variations. Consistent pattern of SNPs across the species revealed their phylogenetic importance. We found two groups of F. tataricum and one of them was closely related with F. dibotrys. Sequence characterization information of PAL gene reported in present investigation can be utilized in genetic improvement of buckwheat in reference to its medicinal value. PMID:26990297

  17. Multi-component removal in flue gas by aqua ammonia

    DOEpatents

    Yeh, James T.; Pennline, Henry W.

    2007-08-14

    A new method for the removal of environmental compounds from gaseous streams, in particular, flue gas streams. The new method involves first oxidizing some or all of the acid anhydrides contained in the gas stream such as sulfur dioxide (SO.sub.2) and nitric oxide (NO) and nitrous oxide (N.sub.2O) to sulfur trioxide (SO.sub.3) and nitrogen dioxide (NO.sub.2). The gas stream is subsequently treated with aqua ammonia or ammonium hydroxide which captures the compounds via chemical absorption through acid-base or neutralization reactions. The products of the reactions can be collected as slurries, dewatered, and dried for use as fertilizers, or once the slurries have been dewatered, used directly as fertilizers. The ammonium hydroxide can be regenerated and recycled for use via thermal decomposition of ammonium bicarbonate, one of the products formed. There are alternative embodiments which entail stoichiometric scrubbing of nitrogen oxides and sulfur oxides with subsequent separate scrubbing of carbon dioxide.

  18. Airborne Observations of Ammonia Emissions from North Carolina Swine Facilities

    NASA Astrophysics Data System (ADS)

    Nowak, J. B.; Neuman, J. A.; Liao, J.; Welti, A.; Middlebrook, A. M.; McKeen, S. A.; Trainer, M.; Parrish, D. D.

    2013-12-01

    Ammonia (NH3) is the dominant gas-phase base in the troposphere. As a consequence, NH3 abundance influences particle formation and composition. Anthropogenic emissions of NH3 can react with sulfuric acid (H2SO4) and nitric acid (HNO3), photochemical oxidation products of sulfur dioxide (SO2) and nitrogen oxides (NOx (NO + NO2)), to form ammoniated particles that typically account for half or more of measured PM2.5 mass in the Eastern US. NH3 emissions are predominantly from agricultural sources, primarily livestock animal waste and crop fertilization. Accurate NH3 emissions estimates from these sources are necessary for developing effective particle control strategies. Swine facilities in North Carolina are one of the largest source of NH3 emissions in the Southeastern US. Airborne measurements of NH3 and particulate ammonium (NH4+) made aboard the NOAA WP-3D aircraft as part of the recent 2013 SENEX field campaign are used to quantify NH3 emissions from North Carolina swine facilities. The observed NH3 emissions are compared to swine facility emissions estimates from current emissions inventories. In addition, the NH3 emissions from swine facilities are placed in the broader context of NH3 sources through comparison to recent emissions observations from dairy facilities in California. The July 10 SENEX WP-3D flight track colored and sized by observed NH3 mixing ratios.

  19. Genomic Characterization of Phenylalanine Ammonia Lyase Gene in Buckwheat.

    PubMed

    Thiyagarajan, Karthikeyan; Vitali, Fabio; Tolaini, Valentina; Galeffi, Patrizia; Cantale, Cristina; Vikram, Prashant; Singh, Sukhwinder; De Rossi, Patrizia; Nobili, Chiara; Procacci, Silvia; Del Fiore, Antonella; Antonini, Alessandro; Presenti, Ombretta; Brunori, Andrea

    2016-01-01

    Phenylalanine Ammonia Lyase (PAL) gene which plays a key role in bio-synthesis of medicinally important compounds, Rutin/quercetin was sequence characterized for its efficient genomics application. These compounds possessing anti-diabetic and anti-cancer properties and are predominantly produced by Fagopyrum spp. In the present study, PAL gene was sequenced from three Fagopyrum spp. (F. tataricum, F. esculentum and F. dibotrys) and showed the presence of three SNPs and four insertion/deletions at intra and inter specific level. Among them, the potential SNP (position 949th bp G>C) with Parsimony Informative Site was selected and successfully utilised to individuate the zygosity/allelic variation of 16 F. tataricum varieties. Insertion mutations were identified in coding region, which resulted the change of a stretch of 39 amino acids on the putative protein. Our Study revealed that autogamous species (F. tataricum) has lower frequency of observed SNPs as compared to allogamous species (F. dibotrys and F. esculentum). The identified SNPs in F. tataricum didn't result to amino acid change, while in other two species it caused both conservative and non-conservative variations. Consistent pattern of SNPs across the species revealed their phylogenetic importance. We found two groups of F. tataricum and one of them was closely related with F. dibotrys. Sequence characterization information of PAL gene reported in present investigation can be utilized in genetic improvement of buckwheat in reference to its medicinal value.

  20. Suppression of Ammonia Volatilization from Urea-Based Fertilizers Using Urease Inhibitors: A Reasonably Available Control Technology for Agriculture?

    NASA Astrophysics Data System (ADS)

    Robarge, W. P.

    2015-12-01

    Ammonia loss from fertilizers can impact formation of atmospheric aerosols, as well as contribute to nitrogen (N) deposition in terrestrial and aquatic ecosystems. Urea is the predominant form of N fertilizer used worldwide due to its high N content (46.6% N) and low cost. Once in contact with soil or vegetation, urea is hydrolyzed to ammonium via naturally occurring urease enzymes. Losses of N from surface applied urea as ammonia can exceed 30%. To address this issue, various physical and chemical mechanisms have been incorporated into granular urea. The most common approach is incorporation of urease inhibitors such as N-(n-butyl) thiophosphoric triamide (NBPT). We have been investigating ammonia volatilization from urea granules (+/- urease inhibitors) in various field and laboratory controlled experiments for the past several years. Laboratory experiments are conducted with a customized growth chamber system designed to continuously measure ammonia volatilization. Field measurements are conducted using a passive sampler technology with an acid-coated trap in PVC cylinders, or annular denuder technology using flow-through PVC chambers. Daily exchanges of acid-coated denuder tubes enhance the sensitivity of ammonia volatilization measurements for the urease-inhibitor treated product. Loss of N from commercial urea granules has ranged from 6 - ~ 35%, depending on ambient temperature. This loss typically occurs within the first 5-10 days under field conditions. Some urease-inhibitors can minimize loss of N via volatilization (< 5%) for up to 20+ days in the absence of a rainfall event. Visual observations have confirmed that on bare soil, treated or untreated urea granules quickly "dissolve" and move into the soil. The accompanying urease-inhibitor formulation moves with the urea continuing to provide protection against reaction with naturally occurring urease enzymes. Use of urease-inhibitors does not guarantee increased crop yields or NUE, but the consistency of